Psychology key terms

A rapid electrical signal that travels down a neuron's axon when the membrane depolarizes past threshold, driven by ion flow and followed by a brief refractory period.

A chemical released at the synapse that binds receptors on a neighboring neuron, exciting or inhibiting it. Common examples include dopamine, serotonin, and GABA.

The process by which a presynaptic neuron reabsorbs released neurotransmitter from the synaptic cleft, ending its signal and recycling the molecule for later release.

The body senses, including touch, pressure, temperature, pain, and proprioception, carried by receptors in skin, muscles, and joints to the somatosensory cortex.

The brain's organization and interpretation of sensory input into meaningful experience, shaped by prior knowledge, expectations, and context rather than raw stimulus alone.

Engagement in an activity for its own sake, because it is interesting or satisfying, rather than for external reward or pressure.

Engagement driven by external outcomes such as rewards, grades, money, or avoiding punishment, rather than by interest in the activity itself.

Learning in which a neutral stimulus comes to elicit a response after repeated pairing with a stimulus that already produces that response, as in Pavlov's dogs.

Learning in which the consequences of a behavior change its future frequency; reinforcement increases behavior and punishment decreases it.

The rule determining when and how often a response is reinforced, such as fixed-ratio or variable-interval, which strongly affects response rate and persistence.

The gradual weakening and disappearance of a conditioned response when the conditioned stimulus is repeatedly presented without the unconditioned stimulus or reinforcement.

A limited-capacity system that temporarily holds and manipulates information during tasks such as reasoning, comprehension, and mental arithmetic.

The relatively permanent store of knowledge and experience, including explicit facts and events and implicit skills, with essentially unlimited capacity.

The initial processing of information into a form the memory system can store; deeper, more meaningful encoding generally produces better later retrieval.

The process of accessing stored information and bringing it back into conscious awareness, as in recall and recognition tasks.

The capacity to reason and solve novel problems independent of acquired knowledge, often measured with abstract puzzles and declining relatively early in aging.

Accumulated knowledge and verbal skills acquired through education and experience, which tends to remain stable or grow across adulthood.

The understanding that objects continue to exist when out of sight, typically developing in infancy and tested by searching for a hidden toy.

The understanding that quantity stays the same despite changes in appearance or arrangement, typically achieved in Piaget's concrete operational stage around age seven.

An enduring emotional bond between infant and caregiver, classified as secure, avoidant, or anxious-ambivalent in the strange-situation procedure.

The discomfort felt when holding conflicting beliefs or when behavior contradicts attitudes, motivating people to change attitudes or rationalize their actions.

Changing one's behavior or beliefs to match those of a group, often to gain approval or because the group appears to provide accurate information.

Compliance with the direct commands of an authority figure, famously studied by Milgram in experiments on administering apparent electric shocks.

The tendency to overattribute others' behavior to stable personality traits while underestimating situational influences, especially for out-group members.

A widely used trait model describing personality along five dimensions: openness, conscientiousness, extraversion, agreeableness, and neuroticism.

The consistency or reproducibility of a measurement across time, items, or raters; a necessary but not sufficient condition for a test to be useful.

The extent to which a test or measure assesses the construct it is intended to assess, supported by content, criterion, and construct evidence.

The standard diagnostic manual used in North America that lists mental disorders with criteria, organized for reliable clinical diagnosis and research.

The co-occurrence of two or more disorders in the same person at the same time, common in clinical populations and complicating diagnosis and treatment.

The view that psychological disorders emerge when a preexisting vulnerability, such as genetic or temperamental risk, interacts with stressful life events.

A structured, goal-oriented treatment that targets maladaptive thoughts and behaviors, using techniques such as cognitive restructuring and behavioral exposure.

A behavioral treatment in which a patient confronts feared stimuli or situations without avoidance, allowing anxiety to extinguish through repeated safe experience.

A class of antidepressant medication that blocks serotonin reuptake, increasing its availability in the synapse; commonly prescribed for depression and anxiety disorders.

Placing participants into experimental conditions by chance so groups are comparable on average, supporting causal inference about the manipulated variable.

An extraneous factor that varies systematically with the independent variable, providing an alternative explanation for observed effects and threatening internal validity.

The ethical requirement that participants receive understandable information about a study's purpose, risks, and right to withdraw before agreeing to take part.

A result unlikely to have occurred by chance if the null hypothesis were true, conventionally judged by a p value below a chosen alpha level.

A school of psychology holding that psychology should study observable behavior rather than introspection or mental states, dominating mid-twentieth-century American psychology.

A committee that reviews research proposals involving human participants to ensure ethical standards such as minimal risk, informed consent, and fair selection are met.