Vocabulary

Ablation: Surgical removal of brain tissue.
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.
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.
Allodynia: Pain due to a stimulus that does not normally provoke pain, e.g., when a light, stroking touch feels painful.
Ambulatory assessment: An overarching term to describe methodologies that assess the behavior, physiology, experience, and environments of humans in naturalistic settings.
Analgesia: Pain relief.
Anterograde amnesia: Inability to form new memories for facts and events after the onset of amnesia.
Autobiographical memory: Memory for the events of one’s life.
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.
Behavioral genetics: The empirical science of how genes and environments combine to generate behavior.
Behaviorism: The study of behavior.
Binocular advantage: Benefits from having two eyes as opposed to a single eye.
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.
Brain stem: The “trunk” of the brain comprised of the medulla, pons, midbrain, and diencephalon.
Callosotomy: Surgical procedure in which the corpus callosum is severed (used to control severe epilepsy).
Case study: A thorough study of a patient (or a few patients) with naturally occurring lesions.
Categorize: To sort or arrange different items into classes or categories.
Cell membrane: A bi-lipid layer of molecules that separates the cell from the surrounding extracellular fluid.
Cerebellum: The distinctive structure at the back of the brain, Latin for “small brain.”
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.
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.
Chronic pain: Persistent or recurrent pain, beyond usual course of acute illness or injury; sometimes present without observable tissue damage or clear cause.
Chunk: The process of grouping information together using our knowledge.
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.
Cognitive psychology: The study of mental processes.
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.
Confounds: Factors that undermine the ability to draw causal inferences from an experiment.
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: 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).
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.
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.
C-pain or Aδ-fibers: C-pain fibers convey noxious, thermal, and heat signals
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.
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.
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.
Dendrite: Part of a neuron that extends away from the cell body and is the main input to the neuron.
Dependent variable: The variable the researcher measures but does not manipulate in an experiment.
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.
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.
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.
Discriminative stimulus: In operant conditioning, a stimulus that signals whether the response will be reinforced. It is said to “set the occasion” for the operant response.
Dissociative amnesia: Loss of autobiographical memories from a period in the past in the absence of brain injury or disease.
Distinctiveness: The principle that unusual events (in a context of similar events) will be recalled and recognized better than uniform (nondistinctive) events.
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.
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: Process by which information gets into memory.
Encoding: The pact of putting information into memory.
Encoding: The initial experience of perceiving and learning events.
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.
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.
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.
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.
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.
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.
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.”
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.
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.
Foils: Any member of a lineup (whether live or photograph) other than the suspect.
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 (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.
g or general mental ability: The general factor common to all cognitive ability measures, “a very general mental capacity that, among other things, involves the ability to reason, plan, solve problems, think abstractly, comprehend complex ideas, learn quickly, and learn from experience. It is not merely book learning, a narrow academic skill, or test-taking smarts. Rather, it reflects a broader and deeper capability for comprehending our surroundings—‘catching on,’ ‘making sense of things,’ or ‘figuring out’ what to do” (Gottfredson, 1997, p. 13).
Gene Selection Theory: The modern theory of evolution by selection by which differential gene replication is the defining process of evolutionary change.
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.
Gestalt psychology: An attempt to study the unity of experience.
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.
Gray matter: The outer grayish regions of the brain comprised of the neurons’ cell bodies.
Gyri: (plural) Folds between sulci in the cortex.
Gyrus: A fold between sulci in the cortex.
Habit: Instrumental behavior that occurs automatically in the presence of a stimulus and is no longer influenced by the animal’s knowledge of the value of the reinforcer. Insensitive to the reinforcer devaluation effect.
Habituation: Occurs when the response to a stimulus decreases with exposure.
Heritability coefficient: An easily misinterpreted statistical construct that purports to measure the role of genetics in the explanation of differences among individuals.
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.
Hypotheses: A logical idea that can be tested.
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, 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.
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.
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.
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.
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.
Lateral inhibition: A signal produced by a neuron aimed at suppressing the response of nearby neurons.
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.
Limbic system: Includes the subcortical structures of the amygdala and hippocampal formation as well as some cortical structures; responsible for aversion and gratification.
Linguistic inquiry and word count: A quantitative text analysis methodology that automatically extracts grammatical and psychological information from a text by counting word frequencies.
Lived day analysis: A methodology where a research team follows an individual around with a video camera to objectively document a person’s daily life as it is lived.
Longitudinal study: A study that follows the same group of individuals over time.
Medial temporal lobes: Inner region of the temporal lobes that includes the hippocampus.
Memory traces: A term indicating the change in the nervous system representing an event.
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.
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.
Motor cortex: Region of the frontal lobe responsible for voluntary movement; the motor cortex has a contralateral representation of the human body.
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 impulse: An electro-chemical signal that enables neurons to communicate.
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.
Observational learning: Learning by observing the behavior of others.
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.
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 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.
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.
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.
Pavlovian conditioning: See classical conditioning.
Perceptual learning: Occurs when aspects of our perception changes as a function of experience.
Phantom pain: Pain that appears to originate in an amputated limb.
Photo spreads: A selection of normally small photographs of faces given to a witness for the purpose of identifying a perpetrator.
Photoactivation: A photochemical reaction that occurs when light hits photoreceptors, producing a neural signal.
Phrenology: A now-discredited field of brain study, popular in the first half of the 19th century that correlated bumps and indentations of the skull with specific functions of the brain.
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”).
Placebo effect: When receiving special treatment or something new affects human behavior.
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 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.
Psychological adaptations: Mechanisms of the mind that evolved to solve specific problems of survival or reproduction; conceptualized as information processing devices.
Psychophysics: Study of the relationships between physical stimuli and the perception of those stimuli.
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.
Quasi-experimental design: An experiment that does not require random assignment to conditions.
Random assignment: Assigning participants to receive different conditions of an experiment by chance.
Realism: A point of view that emphasizes the importance of the senses in providing knowledge of the external world.
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).
Retrieval: Process by which information is accessed from memory and utilized.
Retrieval: The process of accessing stored information.
Retroactive interference: The phenomenon whereby events that occur after some particular event of interest will usually cause forgetting of the original event.
Retrograde amnesia: Inability to retrieve memories for facts and events acquired before the onset of amnesia.
Rods: Photoreceptors that are very sensitive to light and are mostly responsible for night vision.
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.
Satisfaction: Correspondence between an individual’s needs or preferences and the rewards offered by the environment.
Satisfactoriness: Correspondence between an individual’s abilities and the ability requirements of the environment.
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 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.
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).
Sensitization: Occurs when the response to a stimulus increases with exposure
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.
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 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.
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.
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 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.
Specific abilities: Cognitive abilities that contain an appreciable component of g or general ability, but also contain a large component of a more content-focused talent such as mathematical, spatial, or verbal ability; patterns of specific abilities channel development down different paths as a function of an individual’s relative strengths and weaknesses.
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.
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.
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.
Sulci: (plural) Grooves separating folds of the cortex.
Sulcus: A groove separating folds of the cortex.
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.
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.
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.
Taste aversion learning: The phenomenon in which a taste is paired with sickness, and this causes the organism to reject—and dislike—that taste in the future.
Temporal lobe: The part of the cerebrum in front of (anterior to) the occipital lobe and below the lateral fissure; involved in vision, auditory processing, memory, and integrating vision and audition.
Temporal 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.
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.
Transcranial direct current stimulation (tDCS): A neuroscience technique that passes mild electrical current directly through a brain area by placing small electrodes on the skull.
Transcranial magnetic stimulation (TMS): A neuroscience technique whereby a brief magnetic pulse is applied to the head that temporarily induces a weak electrical current that interferes with ongoing activity.
Transduction: The mechanisms that convert stimuli into electrical signals that can be transmitted and processed by the nervous system. Physical or chemical stimulation creates action potentials in a receptor cell in the peripheral nervous system, which is then conducted along the axon to the central nervous system.
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.
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.
Under-determined or misspecified causal models: Psychological frameworks that miss or neglect to include one or more of the critical determinants of the phenomenon under analysis.
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 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.
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.
Working memory: The form of memory we use to hold onto information temporarily, usually for the purposes of manipulation.