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.
Action potential
A transient all-or-nothing electrical current that is conducted down the axon when the membrane potential reaches the threshold of excitation.
Action Potential
A transient all-or-nothing electrical current that is conducted down the axon when the membrane potential reaches the threshold of excitation.
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.
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.
Allodynia
Pain due to a stimulus that does not normally provoke pain, e.g., when a light, stroking touch feels painful.
Alogia
A reduction in the amount of speech and/or increased pausing before the initiation of speech.
Ambulatory assessment
An overarching term to describe methodologies that assess the behavior, physiology, experience, and environments of humans in naturalistic settings.
Amygdala
Two almond-shaped structures located in the medial temporal lobes of the brain.
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.
Analgesia
Pain relief.
Anhedonia
Loss of interest or pleasure in activities one previously found enjoyable or rewarding.
Anhedonia/amotivation
A reduction in the drive or ability to take the steps or engage in actions necessary to obtain the potentially positive outcome.
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.
Aspartate
An excitatory amino acid neurotransmitter that is widely used by vestibular receptors, afferents, and many neurons in the brain.
Attributional style
The tendency by which a person infers the cause or meaning of behaviors or events.
Audience design
Constructing utterances to suit the audience’s knowledge.
Autobiographical memory
Memory for the events of one’s life.
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.
Awareness
A conscious experience or the capability of having conscious experiences, which is distinct from self-awareness, the conscious understanding of one’s own existence and individuality.
Axial plane
See “horizontal plane.”
Axon
Part of the neuron that extends off the soma, splitting several times to connect with other neurons; main output of the neuron.
Axon
Part of the neuron that extends off the soma, splitting several times to connect with other neurons; main output of the neuron.
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.
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 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 Alcohol Content (BAC)
Blood Alcohol Content (BAC): a measure of the percentage of alcohol found in a person’s blood. This measure is typically the standard used to determine the extent to which a person is intoxicated, as in the case of being too impaired to drive a vehicle.
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.
Brain stem
The “trunk” of the brain comprised of the medulla, pons, midbrain, and diencephalon.
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.
Broca’s Area
An area in the frontal lobe of the left hemisphere. Implicated in language production.
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.
Catatonia
Behaviors that seem to reflect a reduction in responsiveness to the external environment. This can include holding unusual postures for long periods of time, failing to respond to verbal or motor prompts from another person, or excessive and seemingly purposeless motor activity.
Categorize
To sort or arrange different items into classes or categories.
Cell membrane
A bi-lipid layer of molecules that separates the cell from the surrounding extracellular fluid.
Central Nervous System
The portion of the nervous system that includes 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
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.
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.
Cingulate gyrus
A medial cortical portion of the nervous tissue that is a part of the limbic system.
Circadian Rhythm
Circadian Rhythm: The physiological sleep-wake cycle. It is influenced by exposure to sunlight as well as daily schedule and activity. Biologically, it includes changes in body temperature, blood pressure and blood sugar.
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.
Common ground
Information that is shared by people who engage in a conversation.
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.
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.
Conscious experience
The first-person perspective of a mental event, such as feeling some sensory input, a memory, an idea, an emotion, a mood, or a continuous temporal sequence of happenings.
Consciousness
Consciousness: the awareness or deliberate perception of a stimulus
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.
Contemplative science
A research area concerned with understanding how contemplative practices such as meditation can affect individuals, including changes in their behavior, their emotional reactivity, their cognitive abilities, and their brains. Contemplative science also seeks insights into conscious experience that can be gained from first-person observations by individuals who have gained extraordinary expertise in introspection.
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.”
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).
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.
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.
Corpus Callosum
The thick bundle of nerve cells that connect the two hemispheres of the brain and allow them to communicate.
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.
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.
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.
Cues
Cues: a stimulus that has a particular significance to the perceiver (e.g., a sight or a sound that has special relevance to the person who saw or heard it)
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.
Delusions
False beliefs that are often fixed, hard to change even in the presence of conflicting information, and often culturally influenced in their content.
Demasculinization
The removal of the potential for male traits.
Dendrite
Part of a neuron that extends away from the cell body and is the main input to the neuron.
Dendrites
Part of a neuron that extends away from the cell body and is the main input to the neuron.
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.
Depressants
Depressants: a class of drugs that slow down the body’s physiological and mental processes.
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.
Diagnostic criteria
The specific criteria used to determine whether an individual has a specific type of psychiatric disorder. Commonly used diagnostic criteria are included in the Diagnostic and Statistical Manual of Mental Disorder, 5th Edition (DSM-5) and the Internal Classification of Disorders, Version 9 (ICD-9).
Dichotic listening
An experimental task in which two messages are presented to different ears.
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.
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
The force on molecules to move from areas of high concentration to areas of low concentration.
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.
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.
Disorganized behavior
Behavior or dress that is outside the norm for almost all subcultures. This would include odd dress, odd makeup (e.g., lipstick outlining a mouth for 1 inch), or unusual rituals (e.g., repetitive hand gestures).
Disorganized speech
Speech that is difficult to follow, either because answers do not clearly follow questions or because one sentence does not logically follow from another.
Dissociation
Dissociation: the heightened focus on one stimulus or thought such that many other things around you are ignored; a disconnect between one’s awareness of their environment and the one object the person is focusing on
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.
Dopamine
A neurotransmitter in the brain that is thought to play an important role in regulating the function of other neurotransmitters.
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.
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.
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.
Electrostatic pressure
The force on two ions with similar charge to repel each other; the force of two ions with opposite charge to attract to one another.
Emotion-focused coping
Coping strategy aimed at reducing the negative emotions associated with a stressful event.
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.
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.
Episodic memory
The ability to learn and retrieve new information or episodes in one’s life.
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.
Euphoria
Euphoria: an intense feeling of pleasure, excitement or happiness.
A physiological measure of large electrical change in the brain produced by sensory stimulation or motor responses.
Excitatory postsynaptic potentials
A depolarizing postsynaptic current that causes the membrane potential to become more positive and move towards the threshold of excitation.
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.”
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.
First-person perspective
Observations made by individuals about their own conscious experiences, also known as introspection or a subjective point of view. Phenomenology refers to the description and investigation of such observations.
Flashbulb memory
Vivid personal memories of receiving the news of some momentous (and usually emotional) event.
Flat affect
A reduction in the display of emotions through facial expressions, gestures, and speech intonation.
Flexible Correction Model
Flexible Correction Model: the ability for people to correct or change their beliefs and evaluations if they believe these judgments have been biased (e.g., if someone realizes they only thought their day was great because it was sunny, they may revise their evaluation of the day to account for this “biasing” influence of the weather)
Forebrain
A part of the nervous system that contains the cerebral hemispheres, thalamus, and hypothalamus.
Fornix
(plural form, fornices) A nerve fiber tract that connects the hippocampus to mammillary bodies.
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 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 capacity
The ability to engage in self-care (cook, clean, bathe), work, attend school, and/or engage in social relationships.
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
(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 (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)
Functional magnetic resonance imaging (fMRI): A neuroimaging technique that infers brain activity by measuring changes in oxygen levels in the blood.
Functional neuroanatomy
Classifying how regions within the nervous system relate to psychology and behavior.
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.
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.
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
A fold between sulci in the cortex.
Gyrus
(plural form, gyri) A bulge that is raised between or among fissures of the convoluted brain.
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.
Hallucinations
Perceptual experiences that occur even when there is no stimulus in the outside world generating the experiences. They can be auditory, visual, olfactory (smell), gustatory (taste), or somatic (touch).
Hallucinogens
Hallucinogens: substances that, when ingested, alter a person’s perceptions, often by creating hallucinations that are not real or distorting their perceptions of time.
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.
Heritability coefficient
An easily misinterpreted statistical construct that purports to measure the role of genetics in the explanation of differences among individuals.
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.
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.
Hostility
An experience or trait with cognitive, behavioral, and emotional components. It often includes cynical thoughts, feelings of emotion, and aggressive behavior.
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.
Hypnosis
Hypnosis: the state of consciousness whereby a person is highly responsive to the suggestions of another; this state usually involves a dissociation with one’s environment and an intense focus on a single stimulus, which is usually accompanied by a sense of relaxation
Hypnotherapy
Hypnotherapy: The use of hypnotic techniques such as relaxation and suggestion to help engineer desirable change such as lower pain or quitting smoking.
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
Part of the diencephalon. Regulates biological drives with pituitary gland.
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.
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.
Immunocytochemistry
A method of staining tissue including the brain, using antibodies.
Implicit Associations Test
Implicit Associations Test (IAT): A computer reaction time test that measures a person’s automatic associations with concepts. For instance, the IAT could be used to measure how quickly a person makes positive or negative evaluations of members of various ethnic groups.
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.
Ingroup
Group to which a person belongs.
Ingroup
A social group to which an individual identifies or belongs.
Inhibitory postsynaptic potentials
A hyperpolarizing postsynaptic current that causes the membrane potential to become more negative and move away from the threshold of excitation.
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.
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.
Ion channels
Proteins that span the cell membrane, forming channels that specific ions can flow through between the intracellular and extracellular space.
Ionotropic receptor
Ion channel that opens to allow ions to permeate the cell membrane under specific conditions, such as the presence of a neurotransmitter or a specific membrane potential.
Jet Lag
Jet Lag: The state of being fatigued and/or having difficulty adjusting to a new time zone after traveling a long distance (across multiple time zones).
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
Damage or tissue abnormality due, for example, to an injury, surgery, or a vascular problem.
Lexicon
Words and expressions.
Limbic System
Includes the subcortical structures of the amygdala and hippocampal formation as well as some cortical structures; responsible for aversion and gratification.
Limbic system
Includes the subcortical structures of the amygdala and hippocampal formation as well as some cortical structures; responsible for aversion and gratification.
Limbic system
A loosely defined network of nuclei in the brain involved with learning and emotion.
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.
Linguistic intergroup bias
A tendency for people to characterize positive things about their ingroup using more abstract expressions, but negative things about their outgroups using more abstract expressions.
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.
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).
Magnetic resonance imaging
A set of techniques that uses strong magnets to measure either the structure of the brain (e.g., gray matter and white matter) or how the brain functions when a person performs cognitive tasks (e.g., working memory or episodic memory) or other types of tasks.
Magnification factor
Cortical space projected by an area of sensory input (e.g., mm of cortex per degree of visual field).
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.
Melatonin
Melatonin: A hormone associated with increased drowsiness and sleep.
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.
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.
Mindfulness
Mindfulness: a state of heightened focus on the thoughts passing through one’s head, as well as a more controlled evaluation of those thoughts (e.g., do you reject or support the thoughts you’re having?)
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.
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.
Myelin Sheath
Fatty tissue, that insulates the axons of the neurons; myelin is necessary for normal conduction of electrical impulses among neurons.
Myelin sheath
Substance around the axon of a neuron that serves as insulation to allow the action potential to conduct rapidly toward the terminal buttons.
Nervous System
The body’s network for electrochemical communication. This system includes all the nerves cells in the body.
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 induction
A process that causes the formation of the neural tube.
Neuroblasts
Brain progenitor cells that asymmetrically divide into other neuroblasts or nerve cells.
Neurodevelopmental
Processes that influence how the brain develops either in utero or as the child is growing up.
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.
Neurons
Individual brain cells
Neuroscience
The study of the nervous system.
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
Chemical substance released by the presynaptic terminal button that acts on the postsynaptic cell.
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.
Neurotransmitters
Chemical substance released by the presynaptic terminal button that acts on the postsynaptic cell.
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.
Noxious stimulus
A stimulus that is damaging or threatens damage to normal tissues.
Nucleus
Collection of nerve cells found in the brain which typically serve a specific function.
Nucleus accumbens
A region of the basal forebrain located in front of the preoptic region.
Observational learning
Learning by observing the behavior of others.
Occipital lobe
The back part of the cerebrum, which houses the visual areas.
Occipital lobe
The back most (posterior) part of the cerebrum; involved in vision.
Occipital Lobe
The back most (posterior) part of the cerebrum; involved in vision.
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.
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.
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
Group to which a person does not belong.
Outgroup
A social group to which an individual does not identify or belong.
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.
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
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
All of the nerve cells that connect the central nervous system to all the other parts of the body.
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.
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.
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”).
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 emission tomography
A technique that uses radio-labelled ligands to measure the distribution of different neurotransmitter receptors in the brain or to measure how much of a certain type of neurotransmitter is released when a person is given a specific type of drug or does a particularly cognitive task.
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.
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.
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.
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.
Priming
Priming: the activation of certain thoughts or feelings that make them easier to think of and act upon
Priming
A stimulus presented to a person reminds him or her about other ideas associated with the stimulus.
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 speed with which an individual can perceive auditory or visual information and respond to it.
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.
Psychoactive drugs
A drug that changes mood or the way someone feels.
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.
Psychopathology
Illnesses or disorders that involve psychological or psychiatric symptoms.
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.
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.
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.
Recoding
The ubiquitous process during learning of taking information in one form and converting it to another form, usually one more easily remembered.
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.
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).
Resting membrane potential
The voltage inside the cell relative to the voltage outside the cell while the cell is a rest (approximately -70 mV).
Retrieval
The process of accessing stored information.
Retrieval
Process by which information is accessed from memory and utilized.
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.
Sapir-Whorf hypothesis
The hypothesis that the language that people use determines their thoughts.
Satiation
The state of being full to satisfaction and no longer desiring to take on more.
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.
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).
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.
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.
Situation model
A mental representation of an event, object, or situation constructed at the time of comprehending a linguistic description.
Social brain hypothesis
The hypothesis that the human brain has evolved, so that humans can maintain larger ingroups.
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 networks
Networks of social relationships among individuals through which information can travel.
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 support
A subjective feeling of psychological or physical comfort provided by family, friends, and others.
S​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.
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.
Socioeconomic status (SES)
A person’s economic and social position based on income, education, and occupation.
Sodium-potassium pump
An ion channel that uses the neuron’s energy (adenosine triphosphate, ATP) to pump three Na+ ions outside the cell in exchange for bringing two K+ ions inside the cell.
Soma
Cell body of a neuron that contains the nucleus and genetic information, and directs protein synthesis.
Soma
Cell body of a neuron that contains the nucleus and genetic information, and directs protein synthesis.
Somatic nervous system
A part of the peripheral nervous system that uses cranial and spinal nerves in volitional actions.
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
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.
Spina bifida
A developmental disease of the spinal cord, where the neural tube does not close caudally.
Spines
Protrusions on the dendrite of a neuron that form synapses with terminal buttons of the presynaptic axon.
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.
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.
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).
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.
Stimulants
Stimulants: a class of drugs that speed up the body’s physiological and mental processes.
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.
Subcortical
Structures that lie beneath the cerebral cortex, but above the brain stem.
Subliminal perception
The ability to process information for meaning when the individual is not consciously aware of that information.
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.
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.
Synapse
Junction between the presynaptic terminal button of one neuron and the dendrite, axon, or soma of another postsynaptic neuron.
Synapse
The tiny space separating neurons.
Synapses
Junction between the presynaptic terminal button of one neuron and the dendrite, axon, or soma of another postsynaptic neuron.
Synaptic Gap
Also known as the synaptic cleft; the small space between the presynaptic terminal button and the postsynaptic dendritic spine, axon, or soma.
Synaptic gap
Also known as the synaptic cleft; the small space between the presynaptic terminal button and the postsynaptic dendritic spine, axon, or soma.
Synaptic vesicles
Groups of neurotransmitters packaged together and located within the terminal button.
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.
Syntax
Rules by which words are strung together to form sentences.
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
An area of the cerebrum that lies below the lateral sulcus; it contains auditory and olfactory (smell) projection regions.
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
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 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
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.
Temporally graded ​​retrograde amnesia
Inability to retrieve memories from just prior to the onset of amnesia with intact memory for more remote events.
Terminal button
The part of the end of the axon that form synapses with postsynaptic dendrite, axon, or soma.
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.
Third-person perspective
Observations made by individuals in a way that can be independently confirmed by other individuals so as to lead to general, objective understanding. With respect to consciousness, third-person perspectives make use of behavioral and neural measures related to conscious experiences.
Threshold of excitation
Specific membrane potential that the neuron must reach to initiate an action potential.
Torsion
A rotational eye movement around the line of sight that consists of a clockwise or counterclockwise direction.
Trance States
Trance: a state of consciousness characterized by the experience of “out-of-body possession,” or an acute dissociation between one’s self and the current, physical environment surrounding them.
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
A process in which physical energy converts into neural energy.
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.
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.”
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.
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.
Vestibulo-ocular reflex
Coordination of motion information with visual information that allows you to maintain your gaze on an object while you move.
Vicarious reinforcement
Learning that occurs by observing the reinforcement or punishment of another person.
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.
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
Short transitory memory processed in the hippocampus.
Working memory
The ability to maintain information over a short period of time, such as 30 seconds or less.
Working memory
The form of memory we use to hold onto information temporarily, usually for the purposes of manipulation.