Vocabulary

5α-reductase: An enzyme required to convert testosterone to 5α-dihydrotestosterone.
Ablation: Surgical removal of brain tissue.
Absolute threshold: The smallest amount of stimulation needed for detection by a sense.
Action potential: A transient all-or-nothing electrical current that is conducted down the axon when the membrane potential reaches the threshold of excitation.
Adaptations: Evolved solutions to problems that historically contributed to reproductive success.
Adoption study: A behavior genetic research method that involves comparison of adopted children to their adoptive and biological parents.
Afferent nerves: Nerves that carry messages to the brain or spinal cord.
Aggression: A form of social interaction that includes threat, attack, and fighting.
Agnosia: Loss of the ability to perceive stimuli.
Agnosias: Due to damage of Wernicke’s area. An inability to recognize objects, words, or faces.
Ambulatory assessment: An overarching term to describe methodologies that assess the behavior, physiology, experience, and environments of humans in naturalistic settings.
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.
Anosmia: Loss of the ability to smell.
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.
Audience design: Constructing utterances to suit the audience’s knowledge.
Audition: Ability to process auditory stimuli. Also called hearing.
Auditory canal: Tube running from the outer ear to the middle ear.
Auditory hair cells: Receptors in the cochlea that transduce sound into electrical potentials.
Autobiographical memory: Memory for the events of one’s life.
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.
Basal ganglia: Subcortical structures of the cerebral hemispheres involved in voluntary movement.
Basic-level category: The neutral, preferred category for a given object, at an intermediate level of specificity.
Behavioral genetics: The empirical science of how genes and environments combine to generate behavior.
Behaviorism: The study of behavior.
Biases: The systematic and predictable mistakes that influence the judgment of even very talented human beings.
Binocular disparity: Difference is images processed by the left and right eyes.
Binocular vision: Our ability to perceive 3D and depth because of the difference between the images on each of our retinas.
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.
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.
Bottom-up processing: Building up to perceptual experience from individual pieces.
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.
Callosotomy: Surgical procedure in which the corpus callosum is severed (used to control severe epilepsy).
Cartesian catastrophe: The idea that mental processes taking place outside conscious awareness are impossible.
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.
Category: A set of entities that are equivalent in some way. Usually the items are similar to one another.
Cause-and-effect: Related to whether we say one variable is causing changes in the other variable, versus other variables that may be related to these two variables.
Cell membrane: A bi-lipid layer of molecules that separates the cell from the surrounding extracellular fluid.
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: Usually refers to the cerebral cortex and associated white matter, but in some texts includes the 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.
Chemical senses: Our ability to process the environmental stimuli of smell and taste.
Chromosomal sex: The sex of an individual as determined by the sex chromosomes (typically XX or XY) received at the time of fertilization.
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: Describes stimulus-stimulus associative learning.
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.
Clock time: Scheduling activities according to the time on the clock.
Cochlea: Spiral bone structure in the inner ear containing auditory hair cells.
Cognitive psychology: The study of mental processes.
Common ground: Information that is shared by people who engage in a conversation.
Computerized axial tomography: A noninvasive brain-scanning procedure that uses X-ray absorption around the head.
Concept: The mental representation of a category.
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 of the retina sensitive to color. Located primarily in the fovea.
Confidence interval: An interval of plausible values for a population parameter; the interval of values within the margin of error of a statistic.
Confounds: Factors that undermine the ability to draw causal inferences from an experiment.
Conscious: Having knowledge of something external or internal to oneself; being aware of and responding to one’s surroundings.
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
Consciousness: Awareness of ourselves and our environment.
Consolidation: The process occurring after encoding that is believed to stabilize memory traces.
Consolidation: Process by which a memory trace is stabilized and transformed into a more durable form.
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).
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.
Correlation: Measures the association between two variables, or how they go together.
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)
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.
Dark adaptation: Adjustment of eye to low levels 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.
Dendrite: Part of a neuron that extends away from the cell body and is the main input to the neuron.
Deoxygenated hemoglobin: Hemoglobin not carrying oxygen.
Dependent variable: The variable the researcher measures but does not manipulate in an experiment.
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.
Depressants: Depressants: a class of drugs that slow down the body’s physiological and mental processes.
Dichotic listening: A task in which different audio streams are presented to each ear. Typically, people are asked to monitor one stream while ignoring the other.
Dichotic listening: An experimental task in which two messages are presented to different ears.
Differential threshold (or difference threshold): The smallest difference needed in order to differentiate two stimuli. (See Just Noticeable Difference (JND))
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.
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.
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.
Distractor task: A task that is designed to make a person think about something unrelated to an impending decision.
Distribution: The pattern of variation in data.
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.
Dorsal pathway: Pathway of visual processing. The “where” pathway.
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.
EEG: (Electroencephalography) The recording of the brain’s electrical activity over a period of time by placing electrodes on the scalp.
Efferent nerves: Nerves that carry messages from the brain to glands and organs in the periphery.
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.
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.
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: The pact of putting information into memory.
Encoding: Process by which information gets 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.
Engrams: A term indicating the change in the nervous system representing an event; also, memory trace.
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.
Eugenics: The practice of selective breeding to promote desired traits.
Euphoria: Euphoria: an intense feeling of pleasure, excitement or happiness.
Eureka experience: When a creative product enters consciousness.
Event-related potentials: A physiological measure of large electrical change in the brain produced by sensory stimulation or motor responses.
Evolution: Change over time. Is the definition changing?
Excitatory postsynaptic potentials: A depolarizing postsynaptic current that causes the membrane potential to become more positive and move towards the threshold of excitation.
Exemplar: An example in memory that is labeled as being in a particular category.
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.
Experimenter expectations: When the experimenter’s expectations influence the outcome of a study.
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.
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.”
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.
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.
Flashbulb memory: A highly detailed and vivid memory of an emotionally significant event.
Flavor: The combination of smell and taste.
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)
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.
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 most forward region (close to forehead) of the cerebral hemispheres.
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.
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 (fMRI): Functional magnetic resonance imaging (fMRI): A neuroimaging technique that infers brain activity by measuring changes in oxygen levels in the blood.
Functionalism: A school of American psychology that focused on the utility of consciousness.
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.
Generalizability: Related to whether the results from the sample can be generalized to a larger population.
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.
Globus pallidus: A nucleus of the basal ganglia.
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.
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: Ability to process gustatory stimuli. Also called 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.
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.
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.
Heuristics: cognitive (or thinking) strategies that simplify decision making by using mental short-cuts
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.
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.
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.
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.
Hypothalamus: Part of the diencephalon. Regulates biological drives with pituitary gland.
Hypotheses: A logical idea that can be tested.
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.
Inattentional blindness: The failure to notice a fully visible, but unexpected, object or event when attention is devoted to something else.
Inattentional deafness: The auditory analog of inattentional blindness. People fail to notice an unexpected sound or voice when attention is devoted to other aspects of a scene.
Incidental learning: Any type of learning that happens without the intention to learn.
Independent variable: The variable the researcher manipulates and controls in an experiment.
Individual differences: Ways in which people differ in terms of their behavior, emotion, cognition, and development.
Ingroup: Group to which a person 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.
Intentional learning: Any type of learning that happens when motivated by intention.
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.
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.
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.
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).
Just noticeable difference (JND): The smallest difference needed in order to differentiate two stimuli. (see Differential Threshold)
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 sulcus: The major fissure that delineates the temporal lobe below the frontal and the parietal lobes.
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.
Lexicon: Words and expressions.
Light adaptation: Adjustment of eye to high levels of light.
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.
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.
Longitudinal study: A study that follows the same group of individuals over time.
Ma: Japanese way of thinking that emphasizes attention to the spaces between things rather than the things themselves.
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).
Margin of error: The expected amount of random variation in a statistic; often defined for 95% confidence level.
Masculinization: The induction of male traits.
Maternal behavior: Parental behavior performed by the mother or other female.
Mechanoreceptors: Mechanical sensory receptors in the skin that response to tactile stimulation.
Medial temporal lobes: Inner region of the temporal lobes that includes the hippocampus.
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.
Mere-exposure effects: The result of developing a more positive attitude towards a stimulus after repeated instances of mere exposure to it.
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.
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: 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.
Monochronic (M-time): Monochronic thinking focuses on doing one activity, from beginning to completion, at a time.
Motor cortex: Region of the frontal lobe responsible for voluntary movement; the motor cortex has a contralateral representation of the human body.
Multimodal perception: The effects that concurrent stimulation in more than one sensory modality has on the perception of events and objects in the world.
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: Substance around the axon of a neuron that serves as insulation to allow the action potential to conduct rapidly toward the terminal buttons.
Natural selection: Differential reproductive success as a consequence of differences in heritable attributes.
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.
Neuroepithelium: The lining of the neural tube.
Neuroscience methods: A research method that deals with the structure or function of the nervous system and brain.
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.
Neurotransmitters: Chemical substance released by the presynaptic terminal button that acts on the postsynaptic cell.
Nociception: Our ability to sense pain.
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.
Nucleus: Collection of nerve cells found in the brain which typically serve a specific function.
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.
Odorants: Chemicals transduced by olfactory receptors.
Olfaction: Ability to process olfactory stimuli. Also called smell.
Olfactory epithelium: Organ containing olfactory receptors.
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: Describes stimulus-response associative learning.
Operant conditioning: See instrumental conditioning.
Operational definitions: How researchers specifically measure a concept.
Opponent-process theory: Theory proposing color vision as influenced by cells responsive to pairs of colors.
Ossicles: A collection of three small bones in the middle ear that vibrate against the tympanic membrane.
Outgroup: Group to which a person does not 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.
Pace of life: The frequency of events per unit of time; also referred to as speed or tempo.
Parameter: A numerical result summarizing a population (e.g., mean, proportion).
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: An area of the cerebrum just behind the central sulcus that is engaged with somatosensory and gustatory sensation.
Parietal lobe: The part of the cerebrum between the frontal and occipital lobes; involved in bodily sensations, visual attention, and integrating the senses.
Participant demand: When participants behave in a way that they think the experimenter wants them to behave.
Paternal behavior: Parental behavior performed by the father or other male.
Pavlovian conditioning: See classical conditioning.
Perception: The psychological process of interpreting sensory information.
Perceptual learning: Occurs when aspects of our perception changes as a function of experience.
Peripheral nervous system: The part of the nervous system that is outside the brain and spinal cord.
Phantom limb: The perception that a missing limb still exists.
Phantom limb pain: Pain in a limb that no longer exists.
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.
Photo spreads: A selection of normally small photographs of faces given to a witness for the purpose of identifying a perpetrator.
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: Outermost portion of the ear.
Placebo effect: When receiving special treatment or something new affects human behavior.
Polychronic (P-time): Polychronic thinking switches back and forth among multiple activities as the situation demands.
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.
Population: A larger collection of individuals that we would like to generalize our results to.
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.
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: Area of the cortex involved in processing auditory stimuli.
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 somatosensory cortex: Area of the cortex involved in processing somatosensory stimuli.
Primary visual cortex: Area of the cortex involved in processing visual stimuli.
Priming: A stimulus presented to a person reminds him or her about other ideas associated with the stimulus.
Priming: Priming: the activation of certain thoughts or feelings that make them easier to think of and act upon
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.
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.
Psychological adaptations: Mechanisms of the mind that evolved to solve specific problems of survival or reproduction; conceptualized as information processing devices.
Psychological essentialism: The belief that members of a category have an unseen property that causes them to be in the category and to have the properties associated with it.
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).
Punisher: A stimulus that decreases the strength of an operant behavior when it is made a consequence of the behavior.
P-value: The probability of observing a particular outcome in a sample, or more extreme, under a conjecture about the larger population or process.
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.
Quasi-experimental design: An experiment that does not require random assignment to conditions.
Random assignment: Using a probability-based method to divide a sample into treatment groups.
Random assignment: Assigning participants to receive different conditions of an experiment by chance.
Random sampling: Using a probability-based method to select a subset of individuals for the sample from the population.
Realism: A point of view that emphasizes the importance of the senses in providing knowledge of the external world.
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.
Resting membrane potential: The voltage inside the cell relative to the voltage outside the cell while the cell is a rest (approximately -70 mV).
Retina: Cell layer in the back of the eye containing photoreceptors.
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.
Rods: Photoreceptors of the retina sensitive to low levels of light. Located around the fovea.
Rostrocaudal: A front-back plane used to identify anatomical structures in the body and the brain.
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.
Sample: The collection of individuals on which we collect data.
Sapir-Whorf hypothesis: The hypothesis that the language that people use determines their thoughts.
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.
Selective listening: A method for studying selective attention in which people focus attention on one auditory stream of information while deliberately ignoring other auditory information.
Semantic memory: The more or less permanent store of knowledge that people have.
Sensation: The physical processing of environmental stimuli by the sense organs.
Sensitization: Occurs when the response to a stimulus increases with exposure
Sensory adaptation: Decrease in sensitivity of a receptor to a stimulus after constant stimulation.
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.
Shape theory of olfaction: Theory proposing that odorants of different size and shape correspond to different smells.
Signal detection: Method for studying the ability to correctly identify sensory stimuli.
Silent language: Cultural norms of time and time use as they pertain to social communication and interaction.
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 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 time: Scheduling by the flow of the activity. Events begin and end when, by mutual consensus, participants “feel” the time is right.
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.
Somatic nervous system: A part of the peripheral nervous system that uses cranial and spinal nerves in volitional actions.
Somatosensation: Ability to sense touch, pain and temperature.
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.
Somatotopic map: Organization of the primary somatosensory cortex maintaining a representation of the arrangement of the body.
Sound waves: Changes in air pressure. The physical stimulus for audition.
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.
Spines: Protrusions on the dendrite of a neuron that form synapses with terminal buttons of the presynaptic axon.
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.
Statistic: A numerical result computed from a sample (e.g., mean, proportion).
Statistical significance: A result is statistically significant if it is unlikely to arise by chance alone.
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.
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.
Subliminal perception: The ability to process information for meaning when the individual is not consciously aware of that information.
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.
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: 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 vesicles: Groups of neurotransmitters packaged together and located within the terminal button.
Syntax: Rules by which words are strung together to form sentences.
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).
Tastants: Chemicals transduced by taste receptor cells.
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.
Taste receptor cells: Receptors that transduce gustatory information.
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 perspective: The extent to which we are oriented toward the past, present, and future.
Temporal resolution: The degree to which one can separate a single point in time from another.
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 part of the diencephalon that works as a gateway for incoming and outgoing information.
Theories: Groups of closely related phenomena or observations.
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.
Tip-of-the-tongue phenomenon: The inability to pull a word from memory even though there is the sensation that that word is available.
Top-down processing: Experience influencing the perception of stimuli.
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: The conversion of one form of energy into another.
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.”
Trichromatic theory: Theory proposing color vision as influenced by three different cones responding preferentially to red, green and blue.
Twin studies: A behavior genetic research method that involves comparison of the similarity of identical (monozygotic; MZ) and fraternal (dizygotic; DZ) twins.
Tympanic membrane: Thin, stretched membrane in the middle ear that vibrates in response to sound. Also called the eardrum.
Typicality: The difference in “goodness” of category members, ranging from the most typical (the prototype) to borderline members.
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.
Unconscious: Not conscious; the part of the mind that affects behavior though it is inaccessible to the conscious mind.
Ventral pathway: Pathway of visual processing. The “what” pathway.
Vestibular system: Parts of the inner ear involved in balance.
Vicarious reinforcement: Learning that occurs by observing the reinforcement or punishment of another person.
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.
Weber’s law: States that just noticeable difference is proportional to the magnitude of the initial stimulus.
Wernicke’s area: A language area in the temporal lobe where linguistic information is comprehended (Also see Broca’s area).
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 form of memory we use to hold onto information temporarily, usually for the purposes of manipulation.