Vocabulary

5α-reductase: An enzyme required to convert testosterone to 5α-dihydrotestosterone.
Abducens nucleus: A group of excitatory motor neurons in the medial brainstem that send projections through the VIth cranial nerve to control the ipsilateral lateral rectus muscle. In addition, abducens interneurons send an excitatory projection across the midline to a subdivision of cells in the ipsilateral oculomotor nucleus, which project through the IIIrd cranial nerve to innervate the ipsilateral medial rectus muscle.
Ablation: Surgical removal of brain tissue.
Acetylcholine: An organic compound neurotransmitter consisting of acetic acid and choline. Depending upon the receptor type, acetycholine can have excitatory, inhibitory, or modulatory effects.
Adaptations: Evolved solutions to problems that historically contributed to reproductive success.
Adherence: In health, it is the ability of a patient to maintain a health behavior prescribed by a physician. This might include taking medication as prescribed, exercising more, or eating less high-fat food.
Adoption study: A behavior genetic research method that involves comparison of adopted children to their adoptive and biological parents.
Affect: An emotional process; includes moods, subjective feelings, and discrete emotions.
Afferent nerve fibers: Single neurons that innervate the receptor hair cells and carry vestibular signals to the brain as part of the vestibulocochlear nerve (cranial nerve VIII).
Afferent nerves: Nerves that carry messages to the brain or spinal cord.
A-fibers: Fast-conducting sensory nerves with myelinated axons. Larger diameter and thicker myelin sheaths increases conduction speed. Aβ-fibers conduct touch signals from low-threshold mechanoreceptors with a velocity of 80 m/s and a diameter of 10 μm; Aδ-fibers have a diameter of 2.5 μm and conduct cold, noxious, and thermal signals at 12 m/s. The third and fastest conducting A-fiber is the Aα, which conducts proprioceptive information with a velocity of 120 m/s and a diameter of 20 μm.
Age identity: How old or young people feel compared to their chronological age; after early adulthood, most people feel younger than their chronological age.
Aggression: Any behavior intended to harm another person who does not want to be harmed.
Aggression: A form of social interaction that includes threat, attack, and fighting.
Agnosias: Due to damage of Wernicke’s area. An inability to recognize objects, words, or faces.
Agonists: A drug that increases or enhances a neurotransmitter’s effect.
Agreeableness: A core personality trait that includes such dispositional characteristics as being sympathetic, generous, forgiving, and helpful, and behavioral tendencies toward harmonious social relations and likeability.
Agreeableness: A personality trait that reflects a person’s tendency to be compassionate, cooperative, warm, and caring to others. People low in agreeableness tend to be rude, hostile, and to pursue their own interests over those of others.
Allodynia: Pain due to a stimulus that does not normally provoke pain, e.g., when a light, stroking touch feels painful.
Altruism: A motivation for helping that has the improvement of another’s welfare as its ultimate goal, with no expectation of any benefits for the helper.
Ambulatory assessment: An overarching term to describe methodologies that assess the behavior, physiology, experience, and environments of humans in naturalistic settings.
Amygdala: A region located deep within the brain in the medial area (toward the center) of the temporal lobes (parallel to the ears). If you could draw a line through your eye sloping toward the back of your head and another line between your two ears, the amygdala would be located at the intersection of these lines. The amygdala is involved in detecting relevant stimuli in our environment and has been implicated in emotional responses.
Amygdala: Two almond-shaped structures located in the medial temporal lobes of the brain.
Analgesia: Pain relief.
Anchoring: The bias to be affected by an initial anchor, even if the anchor is arbitrary, and to insufficiently adjust our judgments away from that anchor.
Anhedonia: Loss of interest or pleasure in activities one previously found enjoyable or rewarding.
Animism: The belief that everyone and everything had a “soul” and that mental illness was due to animistic causes, for example, evil spirits controlling an individual and his/her behavior.
Antagonist: A drug that blocks a neurotransmitter’s effect.
Anterograde amnesia: Inability to form new memories for facts and events after the onset of amnesia.
Aphasia: Due to damage of the Broca’s area. An inability to produce or understand words.
Arcuate fasciculus: A fiber tract that connects Wernicke’s and Broca’s speech areas.
Aromatase: An enzyme that converts androgens into estrogens.
Arousal: cost–reward model: An egoistic theory proposed by Piliavin et al. (1981) that claims that seeing a person in need leads to the arousal of unpleasant feelings, and observers are motivated to eliminate that aversive state, often by helping the victim. A cost–reward analysis may lead observers to react in ways other than offering direct assistance, including indirect help, reinterpretation of the situation, or fleeing the scene.
Aspartate: An excitatory amino acid neurotransmitter that is widely used by vestibular receptors, afferents, and many neurons in the brain.
Asylum: A place of refuge or safety established to confine and care for the mentally ill; forerunners of the mental hospital or psychiatric facility.
Attributional style: The tendency by which a person infers the cause or meaning of behaviors or events.
Autobiographical memory: Memory for the events of one’s life.
Autobiographical narratives: A qualitative research method used to understand characteristics and life themes that an individual considers to uniquely distinguish him- or herself from others.
Automatic process: When a thought, feeling, or behavior occurs with little or no mental effort. Typically, automatic processes are described as involuntary or spontaneous, often resulting from a great deal of practice or repetition.
Autonomic nervous system: A part of the peripheral nervous system that connects to glands and smooth muscles. Consists of sympathetic and parasympathetic divisions.
Availability heuristic: The tendency to judge the frequency or likelihood of an event by the ease with which relevant instances come to mind.
Average life expectancy: Mean number of years that 50% of people in a specific birth cohort are expected to survive. This is typically calculated from birth but is also sometimes re-calculated for people who have already reached a particular age (e.g., 65).
Axial plane: See “horizontal plane.”
Basal ganglia: Subcortical structures of the cerebral hemispheres involved in voluntary movement.
Behavioral genetics: The empirical science of how genes and environments combine to generate behavior.
Behavioral medicine: A field similar to health psychology that integrates psychological factors (e.g., emotion, behavior, cognition, and social factors) in the treatment of disease. This applied field includes clinical areas of study, such as occupational therapy, hypnosis, rehabilitation or medicine, and preventative medicine.
Behaviorism: The study of behavior.
Biases: The systematic and predictable mistakes that influence the judgment of even very talented human beings.
Binocular advantage: Benefits from having two eyes as opposed to a single eye.
Biofeedback: The process by which physiological signals, not normally available to human perception, are transformed into easy-to-understand graphs or numbers. Individuals can then use this information to try to change bodily functioning (e.g., lower blood pressure, reduce muscle tension).
Biomedical Model of Health: A reductionist model that posits that ill health is a result of a deviation from normal function, which is explained by the presence of pathogens, injury, or genetic abnormality.
Biopsychosocial model: A model in which the interaction of biological, psychological, and sociocultural factors is seen as influencing the development of the individual.
Biopsychosocial Model of Health: An approach to studying health and human function that posits the importance of biological, psychological, and social (or environmental) processes.
Blocking: In classical conditioning, the finding that no conditioning occurs to a stimulus if it is combined with a previously conditioned stimulus during conditioning trials. Suggests that information, surprise value, or prediction error is important in conditioning.
Blood-oxygen-level-dependent (BOLD): The signal typically measured in fMRI that results from changes in the ratio of oxygenated hemoglobin to deoxygenated hemoglobin in the blood.
Bouncing balls illusion: The tendency to perceive two circles as bouncing off each other if the moment of their contact is accompanied by an auditory stimulus.
Bounded awareness: The systematic ways in which we fail to notice obvious and important information that is available to us.
Bounded ethicality: The systematic ways in which our ethics are limited in ways we are not even aware of ourselves.
Bounded rationality: Model of human behavior that suggests that humans try to make rational decisions but are bounded due to cognitive limitations.
Bounded self-interest: The systematic and predictable ways in which we care about the outcomes of others.
Bounded willpower: The tendency to place greater weight on present concerns rather than future concerns.
Brain stem: The “trunk” of the brain comprised of the medulla, pons, midbrain, and diencephalon.
Broca’s area: An area in the frontal lobe of the left hemisphere. Implicated in language production.
Bystander intervention: The phenomenon whereby people intervene to help others in need even if the other is a complete stranger and the intervention puts the helper at risk.
Callosotomy: Surgical procedure in which the corpus callosum is severed (used to control severe epilepsy).
Case study: A thorough study of a patient (or a few patients) with naturally occurring lesions.
Categorize: To sort or arrange different items into classes or categories.
Catharsis: Greek term that means to cleanse or purge. Applied to aggression, catharsis is the belief that acting aggressively or even viewing aggression purges angry feelings and aggressive impulses into harmless channels.
Cathartic method: A therapeutic procedure introduced by Breuer and developed further by Freud in the late 19th century whereby a patient gains insight and emotional relief from recalling and reliving traumatic events.
Central nervous system: The part of the nervous system that consists of the brain and spinal cord.
Central sulcus: The major fissure that divides the frontal and the parietal lobes.
Cerebellum: The distinctive structure at the back of the brain, Latin for “small brain.”
Cerebellum: A nervous system structure behind and below the cerebrum. Controls motor movement coordination, balance, equilibrium, and muscle tone.
Cerebral cortex: The outermost gray matter of the cerebrum; the distinctive convoluti characteristic of the mammalian brain.
Cerebral hemispheres: The cerebral cortex, underlying white matter, and subcortical structures.
Cerebrum: Consists of left and right hemispheres that sit at the top of the nervous system and engages in a variety of higher-order functions.
Cerebrum: Usually refers to the cerebral cortex and associated white matter, but in some texts includes the subcortical structures.
C-fibers: C-fibers: Slow-conducting unmyelinated thin sensory afferents with a diameter of 1 μm and a conduction velocity of approximately 1 m/s. C-pain fibers convey noxious, thermal, and heat signals; C-tactile fibers convey gentle touch, light stroking.
Chromosomal sex: The sex of an individual as determined by the sex chromosomes (typically XX or XY) received at the time of fertilization.
Chronic disease: A health condition that persists over time, typically for periods longer than three months (e.g., HIV, asthma, diabetes).
Chronic pain: Persistent or recurrent pain, beyond usual course of acute illness or injury; sometimes present without observable tissue damage or clear cause.
Chronic stress: Discrete or related problematic events and conditions which persist over time and result in prolonged activation of the biological and/or psychological stress response (e.g., unemployment, ongoing health difficulties, marital discord).
Chunk: The process of grouping information together using our knowledge.
Chutes and Ladders: A numerical board game that seems to be useful for building numerical knowledge.
Cingulate gyrus: A medial cortical portion of the nervous tissue that is a part of the limbic system.
Classical conditioning: The procedure in which an initially neutral stimulus (the conditioned stimulus, or CS) is paired with an unconditioned stimulus (or US). The result is that the conditioned stimulus begins to elicit a conditioned response (CR). Classical conditioning is nowadays considered important as both a behavioral phenomenon and as a method to study simple associative learning. Same as Pavlovian conditioning.
Classical conditioning: Describes stimulus-stimulus associative learning.
Cochlea: Snail-shell-shaped organ that transduces mechanical vibrations into neural signals.
Cognitive psychology: The study of mental processes.
Cohort: Group of people typically born in the same year or historical period, who share common experiences over time; sometimes called a generation (e.g., Baby Boom Generation).
Compensatory reflexes: A stabilizing motor reflex that occurs in response to a perceived movement, such as the vestibuloocular reflex, or the postural responses that occur during running or skiing.
Computerized axial tomography: A noninvasive brain-scanning procedure that uses X-ray absorption around the head.
Concrete operations stage: Piagetian stage between ages 7 and 12 when children can think logically about concrete situations but not engage in systematic scientific reasoning.
Conditioned aversions and preferences: Likes and dislikes developed through associations with pleasurable or unpleasurable sensations.
Conditioned compensatory response: In classical conditioning, a conditioned response that opposes, rather than is the same as, the unconditioned response. It functions to reduce the strength of the unconditioned response. Often seen in conditioning when drugs are used as unconditioned stimuli.
Conditioned response (CR): The response that is elicited by the conditioned stimulus after classical conditioning has taken place.
Conditioned stimulus (CS): An initially neutral stimulus (like a bell, light, or tone) that elicits a conditioned response after it has been associated with an unconditioned stimulus.
Cones: Photoreceptors that operate in lighted environments and can encode fine visual details. There are three different kinds (S or blue, M or green and L or red) that are each sensitive to slightly different types of light. Combined, these three types of cones allow you to have color vision.
Conscientiousness: A personality trait that reflects a person’s tendency to be careful, organized, hardworking, and to follow rules.
Consciousness: Awareness of ourselves and our environment.
Conservation problems: Problems pioneered by Piaget in which physical transformation of an object or set of objects changes a perceptually salient dimension but not the quantity that is being asked about.
Consolidation: Process by which a memory trace is stabilized and transformed into a more durable form.
Consolidation: The process occurring after encoding that is believed to stabilize memory traces.
Context: Stimuli that are in the background whenever learning occurs. For instance, the Skinner box or room in which learning takes place is the classic example of a context. However, “context” can also be provided by internal stimuli, such as the sensory effects of drugs (e.g., being under the influence of alcohol has stimulus properties that provide a context) and mood states (e.g., being happy or sad). It can also be provided by a specific period in time—the passage of time is sometimes said to change the “temporal context.”
Continuous development: Ways in which development occurs in a gradual incremental manner, rather than through sudden jumps.
Continuous distributions: Characteristics can go from low to high, with all different intermediate values possible. One does not simply have the trait or not have it, but can possess varying amounts of it.
Contralateral: Literally “opposite side”; used to refer to the fact that the two hemispheres of the brain process sensory information and motor commands for the opposite side of the body (e.g., the left hemisphere controls the right side of the body).
Contrast: Relative difference in the amount and type of light coming from two nearby locations.
Contrast gain: Process where the sensitivity of your visual system can be tuned to be most sensitive to the levels of contrast that are most prevalent in the environment.
Control: Feeling like you have the power to change your environment or behavior if you need or want to.
Converging evidence: Similar findings reported from multiple studies using different methods.
Convoy Model of Social Relations: Theory that proposes that the frequency, types, and reciprocity of social exchanges change with age. These social exchanges impact the health and well-being of the givers and receivers in the convoy.
Coronal plane: A slice that runs from head to foot; brain slices in this plane are similar to slices of a loaf of bread, with the eyes being the front of the loaf.
Cortisol: A hormone made by the adrenal glands, within the cortex. Cortisol helps the body maintain blood pressure and immune function. Cortisol increases when the body is under stress.
Cost–benefit analysis: A decision-making process that compares the cost of an action or thing against the expected benefit to help determine the best course of action.
C-pain or Aδ-fibers: C-pain fibers convey noxious, thermal, and heat signals
Crossmodal phenomena: Effects that concern the influence of the perception of one sensory modality on the perception of another.
Crossmodal receptive field: A receptive field that can be stimulated by a stimulus from more than one sensory modality.
Crossmodal stimulus: A stimulus with components in multiple sensory modalties that interact with each other.
Cross-sectional studies: Research method that provides information about age group differences; age differences are confounded with cohort differences and effects related to history and time of study.
Crowds: Adolescent peer groups characterized by shared reputations or images.
Crystallized intelligence: Type of intellectual ability that relies on the application of knowledge, experience, and learned information.
C-tactile fibers: C-tactile fibers convey gentle touch, light stroking
Cue overload principle: The principle stating that the more memories that are associated to a particular retrieval cue, the less effective the cue will be in prompting retrieval of any one memory.
Cultural display rules: These are rules that are learned early in life that specify the management and modification of emotional expressions according to social circumstances. Cultural display rules can work in a number of different ways. For example, they can require individuals to express emotions “as is” (i.e., as they feel them), to exaggerate their expressions to show more than what is actually felt, to tone down their expressions to show less than what is actually felt, to conceal their feelings by expressing something else, or to show nothing at all.
Cultural relativism: The idea that cultural norms and values of a society can only be understood on their own terms or in their own context.
Cutaneous senses: The senses of the skin: tactile, thermal, pruritic (itchy), painful, and pleasant.
Daily Diary method: A methodology where participants complete a questionnaire about their thoughts, feelings, and behavior of the day at the end of the day.
Daily hassles: Irritations in daily life that are not necessarily traumatic, but that cause difficulties and repeated stress.
Dark adaptation: Process that allows you to become sensitive to very small levels of light, so that you can actually see in the near-absence of light.
Day reconstruction method (DRM): A methodology where participants describe their experiences and behavior of a given day retrospectively upon a systematic reconstruction on the following day.
Decay: The fading of memories with the passage of time.
Declarative memory: Conscious memories for facts and events.
Defeminization: The removal of the potential for female traits.
Demasculinization: The removal of the potential for male traits.
Deoxygenated hemoglobin: Hemoglobin not carrying oxygen.
Depolarization: A change in a cell’s membrane potential, making the inside of the cell more positive and increasing the chance of an action potential.
Depolarized: When receptor hair cells have mechanically gated channels open, the cell increases its membrane voltage, which produces a release of neurotransmitter to excite the innervating nerve fiber.
Depth perception: The ability to actively perceive the distance from oneself of objects in the environment.
Descending pain modulatory system: A top-down pain-modulating system able to inhibit or facilitate pain. The pathway produces analgesia by the release of endogenous opioids. Several brain structures and nuclei are part of this circuit, such as the frontal lobe areas of the anterior cingulate cortex, orbitofrontal cortex, and insular cortex; and nuclei in the amygdala and the hypothalamus, which all project to a structure in the midbrain called the periaqueductal grey (PAG). The PAG then controls ascending pain transmission from the afferent pain system indirectly through the rostral ventromedial medulla (RVM) in the brainstem, which uses ON- and OFF-cells to inhibit or facilitate nociceptive signals at the spinal dorsal horn.
Detection thresholds: The smallest amount of head motion that can be reliably reported by an observer.
Deviant peer contagion: The spread of problem behaviors within groups of adolescents.
Dichotic listening: An experimental task in which two messages are presented to different ears.
Differential susceptibility: Genetic factors that make individuals more or less responsive to environmental experiences.
Diffuse optical imaging (DOI): A neuroimaging technique that infers brain activity by measuring changes in light as it is passed through the skull and surface of the brain.
Diffusion of responsibility: When deciding whether to help a person in need, knowing that there are others who could also provide assistance relieves bystanders of some measure of personal responsibility, reducing the likelihood that bystanders will intervene.
Dihydrotestosterone (DHT): A primary androgen that is an androgenic steroid product of testosterone and binds strongly to androgen receptors.
Directional tuning: The preferred direction of motion that hair cells and afferents exhibit where a peak excitatory response occurs and the least preferred direction where no response occurs. Cells are said to be “tuned” for a best and worst direction of motion, with in-between motion directions eliciting a lesser but observable response.
Discontinuous development: Discontinuous development
Discriminative stimulus: In operant conditioning, a stimulus that signals whether the response will be reinforced. It is said to “set the occasion” for the operant response.
Dissociative amnesia: Loss of autobiographical memories from a period in the past in the absence of brain injury or disease.
Distinctiveness: The principle that unusual events (in a context of similar events) will be recalled and recognized better than uniform (nondistinctive) events.
Divided attention: The ability to flexibly allocate attentional resources between two or more concurrent tasks.
DNA methylation: Covalent modifications of mammalian DNA occurring via the methylation of cytosine, typically in the context of the CpG dinucleotide.
DNA methyltransferases (DNMTs): Enzymes that establish and maintain DNA methylation using methyl-group donor compounds or cofactors. The main mammalian DNMTs are DNMT1, which maintains methylation state across DNA replication, and DNMT3a and DNMT3b, which perform de novo methylation.
Double flash illusion: The false perception of two visual flashes when a single flash is accompanied by two auditory beeps.
Drive state: Affective experiences that motivate organisms to fulfill goals that are generally beneficial to their survival and reproduction.
Early adversity: Single or multiple acute or chronic stressful events, which may be biological or psychological in nature (e.g., poverty, abuse, childhood illness or injury), occurring during childhood and resulting in a biological and/or psychological stress response.
Ecological momentary assessment: An overarching term to describe methodologies that repeatedly sample participants’ real-world experiences, behavior, and physiology in real time.
Ecological validity: The degree to which a study finding has been obtained under conditions that are typical for what happens in everyday life.
Ectoderm: The outermost layer of a developing fetus.
Efferent nerves: Nerves that carry messages from the brain to glands and organs in the periphery.
Egoism: A motivation for helping that has the improvement of the helper’s own circumstances as its primary goal.
Electroencephalogram: A measure of electrical activity generated by the brain’s neurons.
Electroencephalography: A technique that is used to measure gross electrical activity of the brain by placing electrodes on the scalp.
Electroencephalography (EEG): A neuroimaging technique that measures electrical brain activity via multiple electrodes on the scalp.
Electronically activated recorder, or EAR: A methodology where participants wear a small, portable audio recorder that intermittently records snippets of ambient sounds around them.
Emotion-focused coping: Coping strategy aimed at reducing the negative emotions associated with a stressful event.
Empathic concern: According to Batson’s empathy–altruism hypothesis, observers who empathize with a person in need (that is, put themselves in the shoes of the victim and imagine how that person feels) will experience empathic concern and have an altruistic motivation for helping.
Empathy–altruism model: An altruistic theory proposed by Batson (2011) that claims that people who put themselves in the shoes of a victim and imagining how the victim feel will experience empathic concern that evokes an altruistic motivation for helping.
Empirical methods: Approaches to inquiry that are tied to actual measurement and observation.
Empiricism: The belief that knowledge comes from experience.
Encoding: The initial experience of perceiving and learning events.
Encoding: Process by which information gets into memory.
Encoding: The pact of putting information into memory.
Encoding specificity principle: The hypothesis that a retrieval cue will be effective to the extent that information encoded from the cue overlaps or matches information in the engram or memory trace.
Endocrine gland: A ductless gland from which hormones are released into the blood system in response to specific biological signals.
Endophenotypes: A characteristic that reflects a genetic liability for disease and a more basic component of a complex clinical presentation. Endophenotypes are less developmentally malleable than overt behavior.
Endorphin: An endogenous morphine-like peptide that binds to the opioid receptors in the brain and body; synthesized in the body’s nervous system.
Engrams: A term indicating the change in the nervous system representing an event; also, memory trace.
Enzyme: A protein produced by a living organism that allows or helps a chemical reaction to occur.
Enzyme induction: Process through which a drug can enhance the production of an enzyme.
Epigenetics: Heritable changes in gene activity that are not caused by changes in the DNA sequence. http://en.wikipedia.org/wiki/Epigenetics
Epigenetics: The study of heritable changes in gene expression or cellular phenotype caused by mechanisms other than changes in the underlying DNA sequence. Epigenetic marks include covalent DNA modifications and posttranslational histone modifications.
Epigenome: The genome-wide distribution of epigenetic marks.
Episodic memory: Memory for events in a particular time and place.
Error management theory (EMT): A theory of selection under conditions of uncertainty in which recurrent cost asymmetries of judgment or inference favor the evolution of adaptive cognitive biases that function to minimize the more costly errors.
Estrogen: Any of the C18 class of steroid hormones, so named because of the estrus-generating properties in females. Biologically important estrogens include estradiol and estriol.
Ethics: Professional guidelines that offer researchers a template for making decisions that protect research participants from potential harm and that help steer scientists away from conflicts of interest or other situations that might compromise the integrity of their research.
Etiology: The causal description of all of the factors that contribute to the development of a disorder or illness.
Eugenics: The practice of selective breeding to promote desired traits.
Event-related potentials: A physiological measure of large electrical change in the brain produced by sensory stimulation or motor responses.
Event-related potentials (ERP): Measures the firing of groups of neurons in the cortex. As a person views or listens to specific types of information, neuronal activity creates small electrical currents that can be recorded from non-invasive sensors placed on the scalp. ERP provides excellent information about the timing of processing, clarifying brain activity at the millisecond pace at which it unfolds.
Evolution: Change over time. Is the definition changing?
Experience-sampling method: A methodology where participants report on their momentary thoughts, feelings, and behaviors at different points in time over the course of a day.
External validity: The degree to which a finding generalizes from the specific sample and context of a study to some larger population and broader settings.
Exteroception: The sense of the external world, of all stimulation originating from outside our own bodies.
Extinction: Decrease in the strength of a learned behavior that occurs when the conditioned stimulus is presented without the unconditioned stimulus (in classical conditioning) or when the behavior is no longer reinforced (in instrumental conditioning). The term describes both the procedure (the US or reinforcer is no longer presented) as well as the result of the procedure (the learned response declines). Behaviors that have been reduced in strength through extinction are said to be “extinguished.”
Extraversion: A personality trait that reflects a person’s tendency to be sociable, outgoing, active, and assertive.
Facets: Broad personality traits can be broken down into narrower facets or aspects of the trait. For example, extraversion has several facets, such as sociability, dominance, risk-taking and so forth.
Factor analysis: A statistical technique for grouping similar things together according to how highly they are associated.
False memories: Memory for an event that never actually occurred, implanted by experimental manipulation or other means.
Fear conditioning: A type of classical or Pavlovian conditioning in which the conditioned stimulus (CS) is associated with an aversive unconditioned stimulus (US), such as a foot shock. As a consequence of learning, the CS comes to evoke fear. The phenomenon is thought to be involved in the development of anxiety disorders in humans.
Feminization: The induction of female traits.
Fight or flight response: The physiological response that occurs in response to a perceived threat, preparing the body for actions needed to deal with the threat.
Five-Factor Model: (also called the Big Five) The Five-Factor Model is a widely accepted model of personality traits. Advocates of the model believe that much of the variability in people’s thoughts, feelings, and behaviors can be summarized with five broad traits. These five traits are Openness, Conscientiousness, Extraversion, Agreeableness, and Neuroticism.
Flashbulb memory: A highly detailed and vivid memory of an emotionally significant event.
Flashbulb memory: Vivid personal memories of receiving the news of some momentous (and usually emotional) event.
Fluid intelligence: Type of intelligence that relies on the ability to use information processing resources to reason logically and solve novel problems.
Foils: Any member of a lineup (whether live or photograph) other than the suspect.
Forebrain: A part of the nervous system that contains the cerebral hemispheres, thalamus, and hypothalamus.
Foreclosure: Individuals commit to an identity without exploration of options.
Formal operations stage: Piagetian stage starting at age 12 years and continuing for the rest of life, in which adolescents may gain the reasoning powers of educated adults.
Fornix: (plural form, fornices) A nerve fiber tract that connects the hippocampus to mammillary bodies.
Framing: The bias to be systematically affected by the way in which information is presented, while holding the objective information constant.
Frontal lobe: The front most (anterior) part of the cerebrum; anterior to the central sulcus and responsible for motor output and planning, language, judgment, and decision-making.
Frontal lobe: The most forward region (close to forehead) of the cerebral hemispheres.
Full-cycle psychology: A scientific approach whereby researchers start with an observational field study to identify an effect in the real world, follow up with laboratory experimentation to verify the effect and isolate the causal mechanisms, and return to field research to corroborate their experimental findings.
Functional magnetic resonance imaging: (or fMRI) A noninvasive brain-imaging technique that registers changes in blood flow in the brain during a given task (also see magnetic resonance imaging).
Functional magnetic resonance imaging: A measure of changes in the oxygenation of blood flow as areas in the brain become active.
Functional magnetic resonance imaging (fMRI): Functional magnetic resonance imaging (fMRI): A neuroimaging technique that infers brain activity by measuring changes in oxygen levels in the blood.
Functional magnetic resonance imaging (fMRI): Entails the use of powerful magnets to measure the levels of oxygen within the brain that vary with changes in neural activity. That is, as the neurons in specific brain regions “work harder” when performing a specific task, they require more oxygen. By having people listen to or view social percepts in an MRI scanner, fMRI specifies the brain regions that evidence a relative increase in blood flow. In this way, fMRI provides excellent spatial information, pinpointing with millimeter accuracy, the brain regions most critical for different social processes.
Functional neuroanatomy: Classifying how regions within the nervous system relate to psychology and behavior.
Functionalism: A school of American psychology that focused on the utility of consciousness.
G: Short for “general factor” and is often used to be synonymous with intelligence itself.
Gamma-aminobutyric acid: A major inhibitory neurotransmitter in the vestibular commissural system.
Gaze stability: A combination of eye, neck, and head responses that are all coordinated to maintain visual fixation (fovea) upon a point of interest.
Gene: A specific deoxyribonucleic acid (DNA) sequence that codes for a specific polypeptide or protein or an observable inherited trait.
Gene Selection Theory: The modern theory of evolution by selection by which differential gene replication is the defining process of evolutionary change.
General Adaptation Syndrome: A three-phase model of stress, which includes a mobilization of physiological resources phase, a coping phase, and an exhaustion phase (i.e., when an organism fails to cope with the stress adequately and depletes its resources).
Generalize: Generalizing, in science, refers to the ability to arrive at broad conclusions based on a smaller sample of observations. For these conclusions to be true the sample should accurately represent the larger population from which it is drawn.
Genome-wide association study (GWAS): A study that maps DNA polymorphisms in affected individuals and controls matched for age, sex, and ethnic background with the aim of identifying causal genetic variants.
Genotype: The DNA content of a cell’s nucleus, whether a trait is externally observable or not.
Gestalt psychology: An attempt to study the unity of experience.
Global subjective well-being: Individuals’ perceptions of and satisfaction with their lives as a whole.
Globus pallidus: A nucleus of the basal ganglia.
Glutamate: An excitatory amino acid neurotransmitter that is widely used by vestibular receptors, afferents, and many neurons in the brain.
Goal-directed behavior: Instrumental behavior that is influenced by the animal’s knowledge of the association between the behavior and its consequence and the current value of the consequence. Sensitive to the reinforcer devaluation effect.
Gonadal sex: The sex of an individual as determined by the possession of either ovaries or testes. Females have ovaries, whereas males have testes.
Grandiosity: Inflated self-esteem or an exaggerated sense of self-importance and self-worth (e.g., believing one has special powers or superior abilities).
Gray matter: The outer grayish regions of the brain comprised of the neurons’ cell bodies.
Gray matter: Composes the bark or the cortex of the cerebrum and consists of the cell bodies of the neurons (see also white matter).
Gustation: The action of tasting; the ability to taste.
Gyri: (plural) Folds between sulci in the cortex.
Gyrus: (plural form, gyri) A bulge that is raised between or among fissures of the convoluted brain.
Gyrus: A fold between sulci in the cortex.
Habit: Instrumental behavior that occurs automatically in the presence of a stimulus and is no longer influenced by the animal’s knowledge of the value of the reinforcer. Insensitive to the reinforcer devaluation effect.
Habituation: Occurs when the response to a stimulus decreases with exposure.
Hair cells: The receptor cells of the vestibular system. They are termed hair cells due to the many hairlike cilia that extend from the apical surface of the cell into the gelatin membrane. Mechanical gated ion channels in the tips of the cilia open and close as the cilia bend to cause membrane voltage changes in the hair cell that are proportional to the intensity and direction of motion.
Health: According to the World Health Organization, it is a complete state of physical, mental, and social well-being and not merely the absence of disease or infirmity.
Health behavior: Any behavior that is related to health—either good or bad.
Hedonic well-being: Component of well-being that refers to emotional experiences, often including measures of positive (e.g., happiness, contentment) and negative affect (e.g., stress, sadness).
Helpfulness: A component of the prosocial personality orientation; describes individuals who have been helpful in the past and, because they believe they can be effective with the help they give, are more likely to be helpful in the future.
Helping: Prosocial acts that typically involve situations in which one person is in need and another provides the necessary assistance to eliminate the other’s need.
Hemoglobin: The oxygen-carrying portion of a red blood cell.
Heritability coefficient: An easily misinterpreted statistical construct that purports to measure the role of genetics in the explanation of differences among individuals.
Heterogeneity: Inter-individual and subgroup differences in level and rate of change over time.
Heuristics: cognitive (or thinking) strategies that simplify decision making by using mental short-cuts
HEXACO model: The HEXACO model is an alternative to the Five-Factor Model. The HEXACO model includes six traits, five of which are variants of the traits included in the Big Five (Emotionality [E], Extraversion [X], Agreeableness [A], Conscientiousness [C], and Openness [O]). The sixth factor, Honesty-Humility [H], is unique to this model.
Hippocampus: (plural form, hippocampi) A nucleus inside (medial) the temporal lobe implicated in learning and memory.
Histone acetyltransferases (HATs) and histone deacetylases (HDACs): HATs are enzymes that transfer acetyl groups to specific positions on histone tails, promoting an “open” chromatin state and transcriptional activation. HDACs remove these acetyl groups, resulting in a “closed” chromatin state and transcriptional repression.
Histone modifications: Posttranslational modifications of the N-terminal “tails” of histone proteins that serve as a major mode of epigenetic regulation. These modifications include acetylation, phosphorylation, methylation, sumoylation, ubiquitination, and ADP-ribosylation.
Homeostasis: The tendency of an organism to maintain a stable state across all the different physiological systems in the body.
Homeostatic set point: An ideal level that the system being regulated must be monitored and compared to.
Homo habilis: A human ancestor, handy man, that lived two million years ago.
Homo sapiens: Modern man, the only surviving form of the genus Homo.
Homophily: Adolescents tend to associate with peers who are similar to themselves.
Horizontal plane: A slice that runs horizontally through a standing person (i.e., parallel to the floor); slices of brain in this plane divide the top and bottom parts of the brain; this plane is similar to slicing a hamburger bun.
Hormone: An organic chemical messenger released from endocrine cells that travels through the blood to interact with target cells at some distance to cause a biological response.
Hormones: Chemicals released by cells in the brain or body that affect cells in other parts of the brain or body.
Hostile attribution bias: The tendency to perceive ambiguous actions by others as aggressive.
Hostile expectation bias: The tendency to assume that people will react to potential conflicts with aggression.
Hostile perception bias: The tendency to perceive social interactions in general as being aggressive.
Hostility: An experience or trait with cognitive, behavioral, and emotional components. It often includes cynical thoughts, feelings of emotion, and aggressive behavior.
Humorism (or humoralism): A belief held by ancient Greek and Roman physicians (and until the 19th century) that an excess or deficiency in any of the four bodily fluids, or humors—blood, black bile, yellow bile, and phlegm—directly affected their health and temperament.
Hyperpolarization: A change in a cell’s membrane potential, making the inside of the cell more negative and decreasing the chance of an action potential.
Hyperpolarizes: When receptor hair cells have mechanically gated channels close, the cell decreases its membrane voltage, which produces less release of neurotransmitters to inhibit the innervating nerve fiber.
Hypersomnia: Excessive daytime sleepiness, including difficulty staying awake or napping, or prolonged sleep episodes.
Hypothalamic-pituitary-adrenal (HPA) axis: A system that involves the hypothalamus (within the brain), the pituitary gland (within the brain), and the adrenal glands (at the top of the kidneys). This system helps maintain homeostasis (keeping the body’s systems within normal ranges) by regulating digestion, immune function, mood, temperature, and energy use. Through this, the HPA regulates the body’s response to stress and injury.
Hypothalamus: A portion of the brain involved in a variety of functions, including the secretion of various hormones and the regulation of hunger and sexual arousal.
Hypothalamus: A brain structure located below the thalamus and above the brain stem.
Hypothalamus: Part of the diencephalon. Regulates biological drives with pituitary gland.
Hypotheses: A logical idea that can be tested.
Hysteria: Term used by the ancient Greeks and Egyptians to describe a disorder believed to be caused by a woman’s uterus wandering throughout the body and interfering with other organs (today referred to as conversion disorder, in which psychological problems are expressed in physical form).
Identical twins: Two individual organisms that originated from the same zygote and therefore are genetically identical or very similar. The epigenetic profiling of identical twins discordant for disease is a unique experimental design as it eliminates the DNA sequence-, age-, and sex-differences from consideration.
Identity achievement: Individuals have explored different options and then made commitments.
Identity diffusion: Adolescents neither explore nor commit to any roles or ideologies.
Immunocytochemistry: A method of staining tissue including the brain, using antibodies.
Implicit learning: Occurs when we acquire information without intent that we cannot easily express.
Implicit memory: A type of long-term memory that does not require conscious thought to encode. It's the type of memory one makes without intent.
Inattentional blindness: The failure to notice a fully visible object when attention is devoted to something else.
Incidental learning: Any type of learning that happens without the intention to learn.
Independent: Two characteristics or traits are separate from one another-- a person can be high on one and low on the other, or vice-versa. Some correlated traits are relatively independent in that although there is a tendency for a person high on one to also be high on the other, this is not always the case.
Individual differences: Ways in which people differ in terms of their behavior, emotion, cognition, and development.
Information processing theories: Theories that focus on describing the cognitive processes that underlie thinking at any one age and cognitive growth over time.
Ingroup: A social group to which an individual identifies or belongs.
Inhibitory functioning: Ability to focus on a subset of information while suppressing attention to less relevant information.
Instrumental conditioning: Process in which animals learn about the relationship between their behaviors and their consequences. Also known as operant conditioning.
Integrated: The process by which the perceptual system combines information arising from more than one modality.
Intelligence: An individual’s cognitive capability. This includes the ability to acquire, process, recall and apply information.
Intentional learning: Any type of learning that happens when motivated by intention.
Interaural differences: Differences (usually in time or intensity) between the two ears.
Interference: Other memories get in the way of retrieving a desired memory
Internal validity: The degree to which a cause-effect relationship between two variables has been unambiguously established.
Interoception: The sense of the physiological state of the body. Hunger, thirst, temperature, pain, and other sensations relevant to homeostasis. Visceral input such as heart rate, blood pressure, and digestive activity give rise to an experience of the body’s internal states and physiological reactions to external stimulation. This experience has been described as a representation of “the material me,” and it is hypothesized to be the foundation of subjective feelings, emotion, and self-awareness.
Interpersonal: This refers to the relationship or interaction between two or more individuals in a group. Thus, the interpersonal functions of emotion refer to the effects of one’s emotion on others, or to the relationship between oneself and others.
Intersexual selection: A process of sexual selection by which evolution (change) occurs as a consequences of the mate preferences of one sex exerting selection pressure on members of the opposite sex.
Intra- and inter-individual differences: Different patterns of development observed within an individual (intra-) or between individuals (inter-).
Intrapersonal: This refers to what occurs within oneself. Thus, the intrapersonal functions of emotion refer to the effects of emotion to individuals that occur physically inside their bodies and psychologically inside their minds.
Intrasexual competition: A process of sexual selection by which members of one sex compete with each other, and the victors gain preferential mating access to members of the opposite sex.
Introspection: A method of focusing on internal processes.
Invasive Procedure: A procedure that involves the skin being broken or an instrument or chemical being introduced into a body cavity.
IQ: Short for “intelligence quotient.” This is a score, typically obtained from a widely used measure of intelligence that is meant to rank a person’s intellectual ability against that of others.
Kin selection: According to evolutionary psychology, the favoritism shown for helping our blood relatives, with the goals of increasing the likelihood that some portion of our DNA will be passed on to future generations.
Lateral geniculate nucleus: (or LGN) A nucleus in the thalamus that is innervated by the optic nerves and sends signals to the visual cortex in the occipital lobe.
Lateral inhibition: A signal produced by a neuron aimed at suppressing the response of nearby neurons.
Lateral rectus muscle: An eye muscle that turns outward in the horizontal plane.
Lateral sulcus: The major fissure that delineates the temporal lobe below the frontal and the parietal lobes.
Lateral vestibulo-spinal tract: Vestibular neurons that project to all levels of the spinal cord on the ipsilateral side to control posture and balance movements.
Lateralized: To the side; used to refer to the fact that specific functions may reside primarily in one hemisphere or the other (e.g., for the majority individuals, the left hemisphere is most responsible for language).
Law of effect: The idea that instrumental or operant responses are influenced by their effects. Responses that are followed by a pleasant state of affairs will be strengthened and those that are followed by discomfort will be weakened. Nowadays, the term refers to the idea that operant or instrumental behaviors are lawfully controlled by their consequences.
Lesion: A region in the brain that suffered damage through injury, disease, or medical intervention.
Lesion studies: A surgical method in which a part of the animal brain is removed to study its effects on behavior or function.
Lesions: Abnormalities in the tissue of an organism usually caused by disease or trauma.
Lesions: Damage or tissue abnormality due, for example, to an injury, surgery, or a vascular problem.
Lexical hypothesis: The lexical hypothesis is the idea that the most important differences between people will be encoded in the language that we use to describe people. Therefore, if we want to know which personality traits are most important, we can look to the language that people use to describe themselves and others.
Life course theories: Theory of development that highlights the effects of social expectations of age-related life events and social roles; additionally considers the lifelong cumulative effects of membership in specific cohorts and sociocultural subgroups and exposure to historical events.
Life span theories: Theory of development that emphasizes the patterning of lifelong within- and between-person differences in the shape, level, and rate of change trajectories.
Limbic system: A loosely defined network of nuclei in the brain involved with learning and emotion.
Limbic system: Includes the subcortical structures of the amygdala and hippocampal formation as well as some cortical structures; responsible for aversion and gratification.
Limited capacity: The notion that humans have limited mental resources that can be used at a given time.
Linguistic inquiry and word count: A quantitative text analysis methodology that automatically extracts grammatical and psychological information from a text by counting word frequencies.
Lived day analysis: A methodology where a research team follows an individual around with a video camera to objectively document a person’s daily life as it is lived.
Longitudinal studies: Research method that collects information from individuals at multiple time points over time, allowing researchers to track cohort differences in age-related change to determine cumulative effects of different life experiences.
Lordosis: A physical sexual posture in females that serves as an invitation to mate.
Magnetic resonance imaging: Or MRI is a brain imaging noninvasive technique that uses magnetic energy to generate brain images (also see fMRI).
Magnification factor: Cortical space projected by an area of sensory input (e.g., mm of cortex per degree of visual field).
Maladaptive: Term referring to behaviors that cause people who have them physical or emotional harm, prevent them from functioning in daily life, and/or indicate that they have lost touch with reality and/or cannot control their thoughts and behavior (also called dysfunctional).
Masculinization: The induction of male traits.
Maternal behavior: Parental behavior performed by the mother or other female.
McGurk effect: An effect in which conflicting visual and auditory components of a speech stimulus result in an illusory percept.
Mechanically gated ion channels: Ion channels located in the tips of the stereocilia on the receptor cells that open/close as the cilia bend toward the tallest/smallest cilia, respectively. These channels are permeable to potassium ions, which are abundant in the fluid bathing the top of the hair cells.
Medial prefrontal cortex: An area of the brain located in the middle of the frontal lobes (at the front of the head), active when people mentalize about the self and others.
Medial temporal lobes: Inner region of the temporal lobes that includes the hippocampus.
Medial vestibulo-spinal tract: Vestibular nucleus neurons project bilaterally to cervical spinal motor neurons for head and neck movement control. The tract principally functions in gaze direction and stability during motion.
Medulla oblongata: An area just above the spinal cord that processes breathing, digestion, heart and blood vessel function, swallowing, and sneezing.
Memory traces: A term indicating the change in the nervous system representing an event.
Mentalizing: The act of representing the mental states of oneself and others. Mentalizing allows humans to interpret the intentions, beliefs, and emotional states of others.
Mesmerism: Derived from Franz Anton Mesmer in the late 18th century, an early version of hypnotism in which Mesmer claimed that hysterical symptoms could be treated through animal magnetism emanating from Mesmer’s body and permeating the universe (and later through magnets); later explained in terms of high suggestibility in individuals.
Metabolism: Breakdown of substances.
Metabolite: A substance necessary for a living organism to maintain life.
Metacognition: Describes the knowledge and skills people have in monitoring and controlling their own learning and memory.
Mind–body connection: The idea that our emotions and thoughts can affect how our body functions.
Misinformation effect: A memory error caused by exposure to incorrect information between the original event (e.g., a crime) and later memory test (e.g., an interview, lineup, or day in court).
Misinformation effect: When erroneous information occurring after an event is remembered as having been part of the original event.
Mnemonic devices: A strategy for remembering large amounts of information, usually involving imaging events occurring on a journey or with some other set of memorized cues.
Mock witnesses: A research subject who plays the part of a witness in a study.
Moratorium: State in which adolescents are actively exploring options but have not yet made identity commitments.
Motor cortex: Region of the frontal lobe responsible for voluntary movement; the motor cortex has a contralateral representation of the human body.
Multimodal: Of or pertaining to multiple sensory modalities.
Multimodal perception: The effects that concurrent stimulation in more than one sensory modality has on the perception of events and objects in the world.
Multimodal phenomena: Effects that concern the binding of inputs from multiple sensory modalities.
Multisensory convergence zones: Regions in the brain that receive input from multiple unimodal areas processing different sensory modalities.
Multisensory enhancement: See “superadditive effect of multisensory integration.”
Myelin: Fatty tissue, produced by glial cells (see module, “Neurons”) that insulates the axons of the neurons; myelin is necessary for normal conduction of electrical impulses among neurons.
Natural selection: Differential reproductive success as a consequence of differences in heritable attributes.
Nature: The genes that children bring with them to life and that influence all aspects of their development.
Negative state relief model: An egoistic theory proposed by Cialdini et al. (1982) that claims that people have learned through socialization that helping can serve as a secondary reinforcement that will relieve negative moods such as sadness.
Neural crest: A set of primordial neurons that migrate outside the neural tube and give rise to sensory and autonomic neurons in the peripheral nervous system.
Neural impulse: An electro-chemical signal that enables neurons to communicate.
Neural induction: A process that causes the formation of the neural tube.
Neural plasticity: The ability of synapses and neural pathways to change over time and adapt to changes in neural process, behavior, or environment.
Neuroblasts: Brain progenitor cells that asymmetrically divide into other neuroblasts or nerve cells.
Neuroendocrinology: The study of how the brain and hormones act in concert to coordinate the physiology of the body.
Neuroepithelium: The lining of the neural tube.
Neuroscience: The study of the nervous system.
Neuroscience methods: A research method that deals with the structure or function of the nervous system and brain.
Neuroticism: A personality trait that reflects the tendency to be interpersonally sensitive and the tendency to experience negative emotions like anxiety, fear, sadness, and anger.
Neurotransmitter: A chemical messenger that travels between neurons to provide communication. Some neurotransmitters, such as norepinephrine, can leak into the blood system and act as hormones.
Neurotransmitter: A chemical substance produced by a neuron that is used for communication between neurons.
Neurotransmitters: A chemical compound used to send signals from a receptor cell to a neuron, or from one neuron to another. Neurotransmitters can be excitatory, inhibitory, or modulatory and are packaged in small vesicles that are released from the end terminals of cells.
Nociception: The neural process of encoding noxious stimuli, the sensory input from nociceptors. Not necessarily painful, and crucially not necessary for the experience of pain.
Nociceptors: High-threshold sensory receptors of the peripheral somatosensory nervous system that are capable of transducing and encoding noxious stimuli. Nociceptors send information about actual or impending tissue damage to the brain. These signals can often lead to pain, but nociception and pain are not the same.
Nomenclature: Naming conventions.
Nonassociative learning: Occurs when a single repeated exposure leads to a change in behavior.
Noninvasive procedure: A procedure that does not require the insertion of an instrument or chemical through the skin or into a body cavity.
Norm: Assessments are given to a representative sample of a population to determine the range of scores for that population. These “norms” are then used to place an individual who takes that assessment on a range of scores in which he or she is compared to the population at large.
Noxious stimulus: A stimulus that is damaging or threatens damage to normal tissues.
Nucleus accumbens: A region of the basal forebrain located in front of the preoptic region.
Numerical magnitudes: The sizes of numbers.
Nurture: The environments, starting with the womb, that influence all aspects of children’s development.
Object permanence task: The Piagetian task in which infants below about 9 months of age fail to search for an object that is removed from their sight and, if not allowed to search immediately for the object, act as if they do not know that it continues to exist.
Observational learning: Learning by observing the behavior of others.
Occipital lobe: The back most (posterior) part of the cerebrum; involved in vision.
Occipital lobe: The back part of the cerebrum, which houses the visual areas.
Ocial touch hypothesis: Proposes that social touch is a distinct domain of touch. C-tactile afferents form a special pathway that distinguishes social touch from other types of touch by selectively firing in response to touch of social-affective relevance; thus sending affective information parallel to the discriminatory information from the Aβ-fibers. In this way, the socially relevant touch stands out from the rest as having special positive emotional value and is processed further in affect-related brain areas such as the insula.
Oculomotor nuclei: Includes three neuronal groups in the brainstem, the abducens nucleus, the oculomotor nucleus, and the trochlear nucleus, whose cells send motor commands to the six pairs of eye muscles.
Oculomotor nucleus: A group of cells in the middle brainstem that contain subgroups of neurons that project to the medial rectus, inferior oblique, inferior rectus, and superior rectus muscles of the eyes through the 3rd cranial nerve.
Olfaction: The sense of smell; the action of smelling; the ability to smell.
Omnivore: A person or animal that is able to survive by eating a wide range of foods from plant or animal origin.
Openness to Experience: A personality trait that reflects a person’s tendency to seek out and to appreciate new things, including thoughts, feelings, values, and experiences.
Operant: A behavior that is controlled by its consequences. The simplest example is the rat’s lever-pressing, which is controlled by the presentation of the reinforcer.
Operant conditioning: See instrumental conditioning.
Operant conditioning: Describes stimulus-response associative learning.
Opponent Process Theory: Theory of color vision that assumes there are four different basic colors, organized into two pairs (red/green and blue/yellow) and proposes that colors in the world are encoded in terms of the opponency (or difference) between the colors in each pair. There is an additional black/white pair responsible for coding light contrast.
Orbital frontal cortex: A region of the frontal lobes of the brain above the eye sockets.
Orthonasal olfaction: Perceiving scents/smells introduced via the nostrils.
Other-oriented empathy: A component of the prosocial personality orientation; describes individuals who have a strong sense of social responsibility, empathize with and feel emotionally tied to those in need, understand the problems the victim is experiencing, and have a heightened sense of moral obligations to be helpful.
Otoconia: Small calcium carbonate particles that are packed in a layer on top of the gelatin membrane that covers the otolith receptor hair cell stereocilia.
Otolith receptors: Two inner ear vestibular receptors (utricle and saccule) that transduce linear accelerations and head tilt relative to gravity into neural signals that are then transferred to the brain.
Outgroup: A social group to which an individual does not identify or belong.
Overconfident: The bias to have greater confidence in your judgment than is warranted based on a rational assessment.
Oxygenated hemoglobin: Hemoglobin carrying oxygen.
Oxytocin: A peptide hormone secreted by the pituitary gland to trigger lactation, as well as social bonding.
Oxytocin: A nine amino acid mammalian neuropeptide. Oxytocin is synthesized primarily in the brain, but also in other tissues such as uterus, heart and thymus, with local effects. Oxytocin is best known as a hormone of female reproduction due to its capacity to cause uterine contractions and eject milk. Oxytocin has effects on brain tissue, but also acts throughout the body in some cases as an antioxidant or anti-inflammatory.
Pain: Defined as “an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage,” according to the International Association for the Study of Pain.
Parasympathetic nervous system: A division of the autonomic nervous system that is slower than its counterpart—that is, the sympathetic nervous system—and works in opposition to it. Generally engaged in “rest and digest” functions.
Parasympathetic nervous system (PNS): One of the two major divisions of the autonomic nervous system, responsible for stimulation of “rest and digest” activities.
Parental behavior: Behaviors performed in relation to one’s offspring that contributes directly to the survival of those offspring
Parietal lobe: The part of the cerebrum between the frontal and occipital lobes; involved in bodily sensations, visual attention, and integrating the senses.
Parietal lobe: An area of the cerebrum just behind the central sulcus that is engaged with somatosensory and gustatory sensation.
Paternal behavior: Parental behavior performed by the father or other male.
Pavlovian conditioning: See classical conditioning.
Perceptual learning: Occurs when aspects of our perception changes as a function of experience.
Periaqueductal gray: The gray matter in the midbrain near the cerebral aqueduct.
Peripheral nervous system: The part of the nervous system that is outside the brain and spinal cord.
Personal distress: According to Batson’s empathy–altruism hypothesis, observers who take a detached view of a person in need will experience feelings of being “worried” and “upset” and will have an egoistic motivation for helping to relieve that distress.
Personality: Enduring predispositions that characterize a person, such as styles of thought, feelings and behavior.
Personality traits: Enduring dispositions in behavior that show differences across individuals, and which tend to characterize the person across varying types of situations.
Person-situation debate: The person-situation debate is a historical debate about the relative power of personality traits as compared to situational influences on behavior. The situationist critique, which started the person-situation debate, suggested that people overestimate the extent to which personality traits are consistent across situations.
Phantom pain: Pain that appears to originate in an amputated limb.
Pharmacokinetics: The action of a drug through the body, including absorption, distribution, metabolism, and excretion.
Phenotype: The pattern of expression of the genotype or the magnitude or extent to which it is observably expressed—an observable characteristic or trait of an organism, such as its morphology, development, biochemical or physiological properties, or behavior.
Phonemic awareness: Awareness of the component sounds within words.
Photo spreads: A selection of normally small photographs of faces given to a witness for the purpose of identifying a perpetrator.
Photoactivation: A photochemical reaction that occurs when light hits photoreceptors, producing a neural signal.
Phrenology: A now-discredited field of brain study, popular in the first half of the 19th century that correlated bumps and indentations of the skull with specific functions of the brain.
Piaget’s theory: Theory that development occurs through a sequence of discontinuous stages: the sensorimotor, preoperational, concrete operational, and formal operational stages.
Pinna: Visible part of the outer ear.
Placebo effect: Effects from a treatment that are not caused by the physical properties of a treatment but by the meaning ascribed to it. These effects reflect the brain’s own activation of modulatory systems, which is triggered by positive expectation or desire for a successful treatment. Placebo analgesia is the most well-studied placebo effect and has been shown to depend, to a large degree, on opioid mechanisms. Placebo analgesia can be reversed by the pharmacological blocking of  opioid receptors. The word “placebo” is probably derived from the Latin word “placebit” (“it will please”).
Pluralistic ignorance: Relying on the actions of others to define an ambiguous need situation and to then erroneously conclude that no help or intervention is necessary.
Polypharmacy: The use of many medications.
Pons: A bridge that connects the cerebral cortex with the medulla, and reciprocally transfers information back and forth between the brain and the spinal cord.
Positron: A particle having the same mass and numerically equal but positive charge as an electron.
Positron Emission Tomography: (or PET) An invasive procedure that captures brain images with positron emissions from the brain after the individual has been injected with radio-labeled isotopes.
Positron emission tomography (PET): A neuroimaging technique that measures brain activity by detecting the presence of a radioactive substance in the brain that is initially injected into the bloodstream and then pulled in by active brain tissue.
Practitioner-Scholar Model: A model of training of professional psychologists that emphasizes clinical practice.
Prediction error: When the outcome of a conditioning trial is different from that which is predicted by the conditioned stimuli that are present on the trial (i.e., when the US is surprising). Prediction error is necessary to create Pavlovian conditioning (and associative learning generally). As learning occurs over repeated conditioning trials, the conditioned stimulus increasingly predicts the unconditioned stimulus, and prediction error declines. Conditioning works to correct or reduce prediction error.
Preoperational reasoning stage: Period within Piagetian theory from age 2 to 7 years, in which children can represent objects through drawing and language but cannot solve logical reasoning problems, such as the conservation problems.
Preoptic area: A region in the anterior hypothalamus involved in generating and regulating male sexual behavior.
Preoptic region: A part of the anterior hypothalamus.
Preparedness: The idea that an organism’s evolutionary history can make it easy to learn a particular association. Because of preparedness, you are more likely to associate the taste of tequila, and not the circumstances surrounding drinking it, with getting sick. Similarly, humans are more likely to associate images of spiders and snakes than flowers and mushrooms with aversive outcomes like shocks.
Primary auditory cortex: A region of the cortex devoted to the processing of simple auditory information.
Primary Motor Cortex: A strip of cortex just in front of the central sulcus that is involved with motor control.
Primary Somatosensory Cortex: A strip of cerebral tissue just behind the central sulcus engaged in sensory reception of bodily sensations.
Primary visual cortex: A region of the cortex devoted to the processing of simple visual information.
Primary visual cortex (V1): Brain region located in the occipital cortex (toward the back of the head) responsible for processing basic visual information like the detection, thickness, and orientation of simple lines, color, and small-scale motion.
Principle of Inverse Effectiveness: The finding that, in general, for a multimodal stimulus, if the response to each unimodal component (on its own) is weak, then the opportunity for multisensory enhancement is very large. However, if one component—by itself—is sufficient to evoke a strong response, then the effect on the response gained by simultaneously processing the other components of the stimulus will be relatively small.
Problem-focused coping: A set of coping strategies aimed at improving or changing stressful situations.
Processing speed: The time it takes individuals to perform cognitive operations (e.g., process information, react to a signal, switch attention from one task to another, find a specific target object in a complex picture).
Progesterone: A primary progestin that is involved in pregnancy and mating behaviors.
Progestin: A class of C21 steroid hormones named for their progestational (pregnancy-supporting) effects. Progesterone is a common progestin.
Prohormone: A molecule that can act as a hormone itself or be converted into another hormone with different properties. For example, testosterone can serve as a hormone or as a prohormone for either dihydrotestosterone or estradiol.
Prolactin: A protein hormone that is highly conserved throughout the animal kingdom. It has many biological functions associated with reproduction and synergistic actions with steroid hormones.
Proprioceptive: Sensory information regarding muscle position and movement arising from receptors in the muscles, tendons, and joints.
Prosocial behavior: Social behavior that benefits another person.
Prosocial personality orientation: A measure of individual differences that identifies two sets of personality characteristics (other-oriented empathy, helpfulness) that are highly correlated with prosocial behavior.
Psychoactive drugs: A drug that changes mood or the way someone feels.
Psychogenesis: Developing from psychological origins.
Psychological adaptations: Mechanisms of the mind that evolved to solve specific problems of survival or reproduction; conceptualized as information processing devices.
Psychological control: Parents’ manipulation of and intrusion into adolescents’ emotional and cognitive world through invalidating adolescents’ feelings and pressuring them to think in particular ways.
Psychometric approach: Approach to studying intelligence that examines performance on tests of intellectual functioning.
Psychomotor agitation: Increased motor activity associated with restlessness, including physical actions (e.g., fidgeting, pacing, feet tapping, handwringing).
Psychomotor retardation: A slowing of physical activities in which routine activities (e.g., eating, brushing teeth) are performed in an unusually slow manner.
Psychoneuroimmunology: A field of study examining the relationship among psychology, brain function, and immune function.
Psychophysics: Study of the relationships between physical stimuli and the perception of those stimuli.
Psychophysiological methods: Any research method in which the dependent variable is a physiological measure and the independent variable is behavioral or mental (such as memory).
Psychosomatic medicine: An interdisciplinary field of study that focuses on how biological, psychological, and social processes contribute to physiological changes in the body and health over time.
Psychotropic drug: A drug that changes mood or emotion, usually used when talking about drugs prescribed for various mental conditions (depression, anxiety, schizophrenia, etc.).
Punisher: A stimulus that decreases the strength of an operant behavior when it is made a consequence of the behavior.
Punishment: Inflicting pain or removing pleasure for a misdeed. Punishment decreases the likelihood that a behavior will be repeated.
Qualitative changes: Large, fundamental change, as when a caterpillar changes into a butterfly; stage theories such as Piaget’s posit that each stage reflects qualitative change relative to previous stages.
Quantitative changes: Gradual, incremental change, as in the growth of a pine tree’s girth.
Quantitative genetics: Scientific and mathematical methods for inferring genetic and environmental processes based on the degree of genetic and environmental similarity among organisms.
Quantitative law of effect: A mathematical rule that states that the effectiveness of a reinforcer at strengthening an operant response depends on the amount of reinforcement earned for all alternative behaviors. A reinforcer is less effective if there is a lot of reinforcement in the environment for other behaviors.
Realism: A point of view that emphasizes the importance of the senses in providing knowledge of the external world.
Recall: Type of memory task where individuals are asked to remember previously learned information without the help of external cues.
Receptive field: The portion of the world to which a neuron will respond if an appropriate stimulus is present there.
Receptor: A chemical structure on the cell surface or inside of a cell that has an affinity for a specific chemical configuration of a hormone, neurotransmitter, or other compound.
Reciprocal altruism: According to evolutionary psychology, a genetic predisposition for people to help those who have previously helped them.
Recoding: The ubiquitous process during learning of taking information in one form and converting it to another form, usually one more easily remembered.
Recognition: Type of memory task where individuals are asked to remember previously learned information with the assistance of cues.
Reinforcer: Any consequence of a behavior that strengthens the behavior or increases the likelihood that it will be performed it again.
Reinforcer devaluation effect: The finding that an animal will stop performing an instrumental response that once led to a reinforcer if the reinforcer is separately made aversive or undesirable.
Relational aggression: Intentionally harming another person’s social relationships, feelings of acceptance, or inclusion within a group.
Renewal effect: Recovery of an extinguished response that occurs when the context is changed after extinction. Especially strong when the change of context involves return to the context in which conditioning originally occurred. Can occur after extinction in either classical or instrumental conditioning.
Resilience: The ability to “bounce back” from negative situations (e.g., illness, stress) to normal functioning or to simply not show poor outcomes in the face of adversity. In some cases, resilience may lead to better functioning following the negative experience (e.g., post-traumatic growth).
Retrieval: Process by which information is accessed from memory and utilized.
Retrieval: The process of accessing stored information.
Retroactive interference: The phenomenon whereby events that occur after some particular event of interest will usually cause forgetting of the original event.
Retrograde amnesia: Inability to retrieve memories for facts and events acquired before the onset of amnesia.
Retronasal olfaction: Perceiving scents/smells introduced via the mouth/palate.
Reward value: A neuropsychological measure of an outcome’s affective importance to an organism.
Rods: Photoreceptors that are very sensitive to light and are mostly responsible for night vision.
Rostrocaudal: A front-back plane used to identify anatomical structures in the body and the brain.
Rubber hand illusion: The false perception of a fake hand as belonging to a perceiver, due to multimodal sensory information.
Sagittal plane: A slice that runs vertically from front to back; slices of brain in this plane divide the left and right side of the brain; this plane is similar to slicing a baked potato lengthwise.
Satiation: The state of being full to satisfaction and no longer desiring to take on more.
Schema (plural: schemata): A memory template, created through repeated exposure to a particular class of objects or events.
Scientist-practitioner model: A model of training of professional psychologists that emphasizes the development of both research and clinical skills.
Selective attention: The ability to select certain stimuli in the environment to process, while ignoring distracting information.
Self-efficacy: The belief that one can perform adequately in a specific situation.
Self-perceptions of aging: An individual’s perceptions of their own aging process; positive perceptions of aging have been shown to be associated with greater longevity and health.
Semantic memory: The more or less permanent store of knowledge that people have.
Semicircular canals: A set of three inner ear vestibular receptors (horizontal, anterior, posterior) that transduce head rotational accelerations into head rotational velocity signals that are then transferred to the brain. There are three semicircular canals in each ear, with the major planes of each canal being orthogonal to each other.
Sensitization: Occurs when the response to a stimulus increases with exposure
Sensitization: Increased responsiveness of nociceptive neurons to their normal input and/or recruitment of a response to normally subthreshold inputs. Clinically, sensitization may only be inferred indirectly from phenomena such as hyperalgesia or allodynia. Sensitization can occur in the central nervous system (central sensitization) or in the periphery (peripheral sensitization).
Sensorimotor stage: Period within Piagetian theory from birth to age 2 years, during which children come to represent the enduring reality of objects.
Sensory modalities: A type of sense; for example, vision or audition.
Sex determination: The point at which an individual begins to develop as either a male or a female. In animals that have sex chromosomes, this occurs at fertilization. Females are XX and males are XY. All eggs bear X chromosomes, whereas sperm can either bear X or Y chromosomes. Thus, it is the males that determine the sex of the offspring.
Sex differentiation: The process by which individuals develop the characteristics associated with being male or female. Differential exposure to gonadal steroids during early development causes sexual differentiation of several structures including the brain.
Sexual selection: The evolution of characteristics because of the mating advantage they give organisms.
Sexual strategies theory: A comprehensive evolutionary theory of human mating that defines the menu of mating strategies humans pursue (e.g., short-term casual sex, long-term committed mating), the adaptive problems women and men face when pursuing these strategies, and the evolved solutions to these mating problems.
Shadowing: A task in which the individual is asked to repeat an auditory message as it is presented.
Simulation: Imaginary or real imitation of other people’s behavior or feelings.
Social and cultural: Society refers to a system of relationships between individuals and groups of individuals; culture refers to the meaning and information afforded to that system that is transmitted across generations. Thus, the social and cultural functions of emotion refer to the effects that emotions have on the functioning and maintenance of societies and cultures.
Social brain: The set of neuroanatomical structures that allows us to understand the actions and intentions of other people.
Social categorization: The act of mentally classifying someone into a social group (e.g., as female, elderly, a librarian).
Social integration: The size of your social network, or number of social roles (e.g., son, sister, student, employee, team member).
Social Learning Theory: The theory that people can learn new responses and behaviors by observing the behavior of others.
Social models: Authorities that are the targets for observation and who model behaviors.
Social network: Network of people with whom an individual is closely connected; social networks provide emotional, informational, and material support and offer opportunities for social engagement.
Social referencing: This refers to the process whereby individuals look for information from others to clarify a situation, and then use that information to act. Thus, individuals will often use the emotional expressions of others as a source of information to make decisions about their own behavior.
Social support: A subjective feeling of psychological or physical comfort provided by family, friends, and others.
Social support: The perception or actuality that we have a social network that can help us in times of need and provide us with a variety of useful resources (e.g., advice, love, money).
Social touch hypothesis: Proposes that social touch is a distinct domain of touch. C-tactile afferents form a special pathway that distinguishes social touch from other types of touch by selectively firing in response to touch of social-affective relevance; thus sending affective information parallel to the discriminatory information from the Aβ-fibers. In this way, the socially relevant touch stands out from the rest as having special positive emotional value and is processed further in affect-related brain areas such as the insula.
Social zeitgeber: Zeitgeber is German for “time giver.” Social zeitgebers are environmental cues, such as meal times and interactions with other people, that entrain biological rhythms and thus sleep-wake cycle regularity.
Sociocultural theories: Theory founded in large part by Lev Vygotsky that emphasizes how other people and the attitudes, values, and beliefs of the surrounding culture influence children’s development.
Socioeconomic status (SES): A person’s economic and social position based on income, education, and occupation.
Socioemotional Selectivity Theory: Theory proposed to explain the reduction of social partners in older adulthood; posits that older adults focus on meeting emotional over information-gathering goals, and adaptively select social partners who meet this need.
Somatic nervous system: A part of the peripheral nervous system that uses cranial and spinal nerves in volitional actions.
Somatogenesis: Developing from physical/bodily origins.
Somatosensory (body sensations) cortex: The region of the parietal lobe responsible for bodily sensations; the somatosensory cortex has a contralateral representation of the human body.
Somatosensory cortex: Consists of primary sensory cortex (S1) in the postcentral gyrus in the parietal lobes and secondary somatosensory cortex (S2), which is defined functionally and found in the upper bank of the lateral sulcus, called the parietal operculum. Somatosensory cortex also includes parts of the insular cortex.
Somatotopically organized: When the parts of the body that are represented in a particular brain region are organized topographically according to their physical location in the body (see Figure 2 illustration).
Spatial principle of multisensory integration: The finding that the superadditive effects of multisensory integration are observed when the sources of stimulation are spatially related to one another.
Spatial resolution: A term that refers to how small the elements of an image are; high spatial resolution means the device or technique can resolve very small elements; in neuroscience it describes how small of a structure in the brain can be imaged.
Spatial resolution: The degree to which one can separate a single object in space from another.
Spina bifida: A developmental disease of the spinal cord, where the neural tube does not close caudally.
Spinothalamic tract: Runs through the spinal cord’s lateral column up to the thalamus. C-fibers enter the dorsal horn of the spinal cord and form a synapse with a neuron that then crosses over to the lateral column and becomes part of the spinothalamic tract.
Split-brain patient: A patient who has had most or all of his or her corpus callosum severed.
Spontaneous recovery: Recovery of an extinguished response that occurs with the passage of time after extinction. Can occur after extinction in either classical or instrumental conditioning.
Standardize: Assessments that are given in the exact same manner to all people . With regards to intelligence tests standardized scores are individual scores that are computed to be referenced against normative scores for a population (see “norm”).
Stereocilia: Hairlike projections from the top of the receptor hair cells. The stereocilia are arranged in ascending height and when displaced toward the tallest cilia, the mechanical gated channels open and the cell is excited (depolarized). When the stereocilia are displaced toward the smallest cilia, the channels close and the cell is inhibited (hyperpolarized).
Stereotype threat: The phenomenon in which people are concerned that they will conform to a stereotype or that their performance does conform to that stereotype, especially in instances in which the stereotype is brought to their conscious awareness.
Stereotypes: The beliefs or attributes we associate with a specific social group. Stereotyping refers to the act of assuming that because someone is a member of a particular group, he or she possesses the group’s attributes. For example, stereotyping occurs when we assume someone is unemotional just because he is man, or particularly athletic just because she is African American.
Stimulus control: When an operant behavior is controlled by a stimulus that precedes it.
Storage: The stage in the learning/memory process that bridges encoding and retrieval; the persistence of memory over time.
Stress: A pattern of physical and psychological responses in an organism after it perceives a threatening event that disturbs its homeostasis and taxes its abilities to cope with the event.
Stress: A threat or challenge to our well-being. Stress can have both a psychological component, which consists of our subjective thoughts and feelings about being threatened or challenged, as well as a physiological component, which consists of our body’s response to the threat or challenge (see “fight or flight response”).
Stressor: An event or stimulus that induces feelings of stress.
Stria terminalis: A band of fibers that runs along the top surface of the thalamus.
Structuralism: A school of American psychology that sought to describe the elements of conscious experience.
Subcortical: Structures that lie beneath the cerebral cortex, but above the brain stem.
Subjective age: A multidimensional construct that indicates how old (or young) a person feels and into which age group a person categorizes him- or herself
Subliminal perception: The ability to process information for meaning when the individual is not consciously aware of that information.
Successful aging: Includes three components: avoiding disease, maintaining high levels of cognitive and physical functioning, and having an actively engaged lifestyle.
Suicidal ideation: Recurring thoughts about suicide, including considering or planning for suicide, or preoccupation with suicide.
Sulci: (plural) Grooves separating folds of the cortex.
Sulcus: A groove separating folds of the cortex.
Sulcus: (plural form, sulci) The crevices or fissures formed by convolutions in the brain.
Superadditive effect of multisensory integration: The finding that responses to multimodal stimuli are typically greater than the sum of the independent responses to each unimodal component if it were presented on its own.
Superior temporal sulcus: The sulcus (a fissure in the surface of the brain) that separates the superior temporal gyrus from the middle temporal gyrus. Located in the temporal lobes (parallel to the ears), it is involved in perception of biological motion or the movement of animate objects.
Supernatural: Developing from origins beyond the visible observable universe.
Sympathetic nervous system: A branch of the autonomic nervous system that controls many of the body’s internal organs. Activity of the SNS generally mobilizes the body’s fight or flight response.
Sympathetic nervous system: A division of the autonomic nervous system, that is faster than its counterpart that is the parasympathetic nervous system and works in opposition to it. Generally engaged in “fight or flight” functions.
Sympathetic nervous system (SNS): One of the two major divisions of the autonomic nervous system, responsible for stimulation of “fight or flight” activities.
Synapse: The tiny space separating neurons.
Syndrome: Involving a particular group of signs and symptoms.
Synesthesia: The blending of two or more sensory experiences, or the automatic activation of a secondary (indirect) sensory experience due to certain aspects of the primary (direct) sensory stimulation.
System 1: Our intuitive decision-making system, which is typically fast, automatic, effortless, implicit, and emotional.
System 2: Our more deliberative decision-making system, which is slower, conscious, effortful, explicit, and logical.
Systematic observation: The careful observation of the natural world with the aim of better understanding it. Observations provide the basic data that allow scientists to track, tally, or otherwise organize information about the natural world.
Target cell: A cell that has receptors for a specific chemical messenger (hormone or neurotransmitter).
Taste aversion learning: The phenomenon in which a taste is paired with sickness, and this causes the organism to reject—and dislike—that taste in the future.
Temporal lobe: The part of the cerebrum in front of (anterior to) the occipital lobe and below the lateral fissure; involved in vision, auditory processing, memory, and integrating vision and audition.
Temporal lobe: An area of the cerebrum that lies below the lateral sulcus; it contains auditory and olfactory (smell) projection regions.
Temporal parietal junction: The area where the temporal lobes (parallel to the ears) and parieta lobes (at the top of the head toward the back) meet. This area is important in mentalizing and distinguishing between the self and others.
Temporal resolution: A term that refers to how small a unit of time can be measured; high temporal resolution means capable of resolving very small units of time; in neuroscience it describes how precisely in time a process can be measured in the brain.
Temporal resolution: The degree to which one can separate a single point in time from another.
Temporally graded retrograde amnesia: Inability to retrieve memories from just prior to the onset of amnesia with intact memory for more remote events.
Testosterone: The primary androgen secreted by the testes of most vertebrate animals, including men.
Thalamus: A structure in the midline of the brain located between the midbrain and the cerebral cortex.
Thalamus: A part of the diencephalon that works as a gateway for incoming and outgoing information.
Theories: Groups of closely related phenomena or observations.
Tip-of-the-tongue phenomenon: The inability to pull a word from memory even though there is the sensation that that word is available.
Torsion: A rotational eye movement around the line of sight that consists of a clockwise or counterclockwise direction.
“Traitement moral” (moral treatment): A therapeutic regimen of improved nutrition, living conditions, and rewards for productive behavior that has been attributed to Philippe Pinel during the French Revolution, when he released mentally ill patients from their restraints and treated them with compassion and dignity rather than with contempt and denigration.
Transcranial direct current stimulation (tDCS): A neuroscience technique that passes mild electrical current directly through a brain area by placing small electrodes on the skull.
Transcranial magnetic stimulation (TMS): A neuroscience technique whereby a brief magnetic pulse is applied to the head that temporarily induces a weak electrical current that interferes with ongoing activity.
Transduction: The mechanisms that convert stimuli into electrical signals that can be transmitted and processed by the nervous system. Physical or chemical stimulation creates action potentials in a receptor cell in the peripheral nervous system, which is then conducted along the axon to the central nervous system.
Transduction: A process in which physical energy converts into neural energy.
Transfer-appropriate processing: A principle that states that memory performance is superior when a test taps the same cognitive processes as the original encoding activity.
Transverse plane: See “horizontal plane.”
Trephination: The drilling of a hole in the skull, presumably as a way of treating psychological disorders.
Trichromacy theory: Theory that proposes that all of your color perception is fundamentally based on the combination of three (not two, not four) different color signals.
Twin studies: A behavior genetic research method that involves comparison of the similarity of identical (monozygotic; MZ) and fraternal (dizygotic; DZ) twins.
Tympanic membrane: Ear drum, which separates the outer ear from the middle ear.
Type A Behavior: Type A behavior is characterized by impatience, competitiveness, neuroticism, hostility, and anger.
Type B Behavior: Type B behavior reflects the absence of Type A characteristics and is represented by less competitive, aggressive, and hostile behavior patterns.
Unconditioned response (UR): In classical conditioning, an innate response that is elicited by a stimulus before (or in the absence of) conditioning.
Unconditioned stimulus (US): In classical conditioning, the stimulus that elicits the response before conditioning occurs.
Unimodal: Of or pertaining to a single sensory modality.
Unimodal components: The parts of a stimulus relevant to one sensory modality at a time.
Unimodal cortex: A region of the brain devoted to the processing of information from a single sensory modality.
Vagus nerve: The 10th cranial nerve. The mammalian vagus has an older unmyelinated branch which originates in the dorsal motor complex and a more recently evolved, myelinated branch, with origins in the ventral vagal complex including the nucleus ambiguous. The vagus is the primary source of autonomic-parasympathetic regulation for various internal organs, including the heart, lungs and other parts of the viscera. The vagus nerve is primarily sensory (afferent), transmitting abundant visceral input to the central nervous system.
Vasopressin: A nine amino acid mammalian neuropeptide. Vasopressin is synthesized primarily in the brain, but also may be made in other tissues. Vasopressin is best known for its effects on the cardiovascular system (increasing blood pressure) and also the kidneys (causing water retention). Vasopressin has effects on brain tissue, but also acts throughout the body.
Vergence angle: The angle between the line of sight for the two eyes. Low vergence angles indicate far-viewing objects, whereas large angles indicate viewing of near objects.
Vestibular compensation: Following injury to one side of vestibular receptors or the vestibulocochlear nerve, the central vestibular nuclei neurons gradually recover much of their function through plasticity mechanisms. The recovery is never complete, however, and extreme motion environments can lead to dizziness, nausea, problems with balance, and spatial memory.
Vestibular efferents: Nerve fibers originating from a nucleus in the brainstem that project from the brain to innervate the vestibular receptor hair cells and afferent nerve terminals. Efferents have a modulatory role on their targets, which is not well understood.
Vestibular system: Consists of a set of motion and gravity detection receptors in the inner ear, a set of primary nuclei in the brainstem, and a network of pathways carrying motion and gravity signals to many regions of the brain.
Vestibulocochlear nerve: The VIIIth cranial nerve that carries fibers innervating the vestibular receptors and the cochlea.
Vestibulo-ocular reflex: Coordination of motion information with visual information that allows you to maintain your gaze on an object while you move.
Vestibuloocular reflex: Eye movements produced by the vestibular brainstem that are equal in magnitude and opposite in direction to head motion. The VOR functions to maintain visual stability on a point of interest and is nearly perfect for all natural head movements.
Vicarious reinforcement: Learning that occurs by observing the reinforcement or punishment of another person.
Violence: Aggression intended to cause extreme physical harm, such as injury or death.
Visual cortex: The part of the brain that processes visual information, located in the back of the brain.
Visual hemifield: The half of visual space (what we see) on one side of fixation (where we are looking); the left hemisphere is responsible for the right visual hemifield, and the right hemisphere is responsible for the left visual hemifield.
Voltage: The difference in electric charge between two points.
Wernicke’s area: A language area in the temporal lobe where linguistic information is comprehended (Also see Broca’s area).
What pathway: Pathway of neural processing in the brain that is responsible for your ability to recognize what is around you.
Where-and-How pathway: Pathway of neural processing in the brain that is responsible for you knowing where things are in the world and how to interact with them.
White coat hypertension: A phenomenon in which patients exhibit elevated blood pressure in the hospital or doctor’s office but not in their everyday lives.
White matter: The inner whitish regions of the cerebrum comprised of the myelinated axons of neurons in the cerebral cortex.
White matter: Regions of the nervous system that represent the axons of the nerve cells; whitish in color because of myelination of the nerve cells.
Working memory: The form of memory we use to hold onto information temporarily, usually for the purposes of manipulation.
Working memory: Short transitory memory processed in the hippocampus.
Working memory: Memory system that allows for information to be simultaneously stored and utilized or manipulated.