AP psych vocabulary (APA dictionary)

Absolute threshold

minimum amount of stimulation required to trigger a reaction or produce a sensation

accommodation of lens

the focus of the eye is changed to allow near or distant objects to form sharp images on the retin

action potential

change in electric potential that propagates along the axon of a neuron during the transmission of a nerve impulse or the contraction of a muscle.

activation-synthesis

explains dreams as a product of cortical interpretation of random neural activity rising from the brainstem (specifically the pons)

adaptations

adjustment of a sense organ to the intensity or quality of stimulation, resulting in a temporary change in sensory or perceptual experience

addiction

a state of psychological and/or physical dependence on the use of drugs or other substances, such as alcohol, or on activities or behaviors.

afterimages

the image that remains after a stimulus ends or is removed.

agonists

a drug or other chemical agent that binds to a particular receptor and produces a physiological effect, typically one similar to that of the body’s own neurotransmitter at that receptor.

antagonists

a drug or other chemical agent that inhibits the action of another substance.

all or nothing Principle

the principle that the amplitude of the action potential in a neuron is independent of the magnitude of the stimulus.

amygdala

an almond-shaped structure in the temporal lobe that is a component of the limbic system. Functions as well as an important role in memory, emotion, perception of threat, and fear learning

association areas

regions of the cerebral cortex that integrate and interpret information from various sources

autonomic nervous system

portion of the nervous system innervating smooth muscle and glands, including the circulatory, digestive, respiratory, and reproductive organs

autopsy

procedure in which the body of a dead person is examined in an effort to determine the exact cause and time of death.

axon

the long, thin, hollow, cylindrical extension of a neuron that normally carries a nerve impulse away from the cell body.

blind spot

the area of the monocular visual field in which stimulation cannot be perceived because the image falls on the site of the optic disk in the eye.

blindsight

the capacity of some individuals with damage to the striate cortex (primary visual cortex or area V1) to detect and even localize visual stimuli presented to the blind portion of the visual field.

EEG

method of studying brain waves using an instrument (electroencephalograph) that amplifies and records the electrical activity of the brain through electrodes placed at various points on the scalp

PET

an imaging technique using radiolabeled tracers, such as 2-deoxyglucose labeled with fluorine-18, that emit positively charged particles (positrons) as they are metabolized. Used to evaluate cerebral metabolism and blood flow as well as the binding and transport of neurotransmitter systems in the brain

CT

a medical imaging technique that uses X-rays to create detailed images of internal organs, bones, and blood vessels. 

MRI

a noninvasive diagnostic technique that uses the responses of hydrogen in tissue molecules to strong magnetic impulses to form a three-dimensional picture of body organs and tissues (e.g., the brain) with more accuracy than computed tomography.

fMRI

a form of magnetic resonance imaging used to localize areas of cognitive activation, based on the correlation between brain activity and blood property changes linked to local changes in blood flow to the brain.

brain laterization

the concept that different functions and processes are primarily located in one hemisphere of the brain, either the left or right

alpha (Brain wave)

low-amplitude brain wave (frequency 8–12 Hz) that typically occurs when the eyes are closed or unfocused and no deliberate mental tasks are taking place

beta (Brain wave)

the type of brain wave (frequency 13–30 Hz) associated with alert wakefulness and intense mental activity.

delta (brain wave)

regular-shaped waves that have a frequency of 1 to 3 Hz. They are associated with deep sleep

theta (brain wave)

a type of regular brain wave with a frequency of 4 to 7 Hz. these waves occur during REM sleep in nonhuman animals, Stage 2 NREM sleep in humans, and the drowsy state prior to sleep onset in newborn infants, adolescents, and adults.

brainstem

the part of the brain that connects the cerebrum with the spinal cord. It includes the midbrain, pons, and medulla oblongata and is involved in the autonomic control of visceral activity, such as salivation, respiration, heartbeat, digestion, and other so called vegetative functions.

broca’s area

a region of the posterior portion of the inferior frontal convolution of a cerebral hemisphere that is associated with the production of speech.

broca’s aphasia

characterized by nonfluent conversational speech and slow, halting speech production. Auditory comprehension is relatively good for everyday conversation, but there is considerable difficulty with complex syntax or multistep commands.

central nervous system

the entire complex of neurons, axons, and supporting tissue that constitute the brain and spinal cord.

cerebellum

a portion of the hindbrain dorsal to the rest of the brainstem and modulates muscular contractions to produce smooth, accurately timed ballistic movements; it helps maintain equilibrium by predicting body positions ahead of actual body movements, and it is required for some kinds of motor conditioning

cerebral Cortex

the layer of gray matter that covers the outside of the cerebral hemispheres in the brain and is associated with higher cognitive functions, such as language, learning, perception, and planning

cerebrum

the largest part of the brain, forming most of the forebrain and lying in front of and above the cerebellum

circadian rhythm

any periodic variation in physiological or behavioral activity that repeats at approximately 24-hour intervals

confederate

poses as a participant but whose behavior is rehearsed prior to the experiment

consciousness

the state of being conscious

contralaterality

corpus callosum

a large tract of nerve fibers running across the longitudinal fissure of the brain and connecting the cerebral hemispheres

cortical areas of the brain

Brodmann’s area; cerebral cortex

debriefing

the process of giving participants in a completed research project a fuller explanation of the study in which they participated than was possible before or during the research.

informed consent

a person’s voluntary agreement to participate in a procedure on the basis of their understanding of its nature, its potential benefits and possible risks, and available alternatives.

deception

any distortion of or withholding of fact with the purpose of misleading others

deep sleep

the stage of the sleep cycle in which arousal thresholds are highest and consciousness is taken to be least likely.

dendrites

a branching, threadlike extension of the cell body that increases the receptive surface of a neuron.

depolarization

a reduction in the electric potential across the plasma membrane of a cell, especially a neuron, such that the inner surface of the membrane becomes less negative in relation to the outer surface.

depressants

having the quality of diminishing or retarding a function or activity of a body system or organ

dichromatism

partial color blindness in which the eye contains only two types of cone photopigment instead of the typical three: Lack of the third pigment leads to confusion between certain colors

monochromatism

a partial color blindness in which the eye contains only one type of cone photopigment instead of the typical three: Everything appears in various shades of a single color.

insomnia

difficulty in initiating or maintaining a restorative sleep, which results in fatigue, the severity or persistence of which causes clinically significant distress or impairment in functioning

narcolepsy

a disorder consisting of excessive daytime sleepiness accompanied by brief “attacks” of sleep during waking hours

REM sleep behavior disorder

a sleep disorder involving motor activity during REM sleep, which typically includes a physical enactment of dream sequences.

sleep apnea

the temporary cessation of breathing while asleep, which occurs when the upper airway briefly becomes blocked (obstructive sleep apnea) or when the respiratory centers in the brain fail to stimulate respiration

somnambulism (sleep walking)

a sleep disorder characterized by persistent incidents of complex motor activity during slow-wave NREM sleep. These episodes typically occur during the first hours of sleep and involve getting out of bed and walking, although the individual may also perform more complicated tasks, such as eating, talking, or operating machinery.

drug tolerance

a condition, resulting from persistent use of a drug, characterized by a markedly diminished effect with regular use of the same dose of the drug or by a need to increase the dose markedly over time to achieve the same desired effect.

drug withdrawal

a syndrome that develops after cessation of prolonged, heavy consumption of a substance.

dual processing

1. the theory that the response made by an individual to a stimulus that permits behavioral control involves two stages: (a) a decision as to whether or not to respond and (b) a choice between alternative responses.

sleep deprivation

the condition of getting insufficient sleep. This may occur as a result of illness, shift work, or lifestyle considerations (e.g., having a newborn, staying up late to study)

electrochemical reaction

the neural communication process, where neurons communicate through both electrical signals (the "electro" part) and chemical signals (the "chemical" part). 

endrocrine system

a network of glands that produce and release hormones, chemical messengers that regulate various bodily functions, including metabolism, reproduction, growth, and development, and influence mood, energy, and behavior

epigenetics

the study of heritable chemical modifications to DNA that alter gene activity without changing nucleotide sequence.

eugenics

a social and political philosophy, based loosely on Charles Darwin’s evolutionary theory and Francis Galton’s research on hereditary genius, that seeks to eradicate genetic defects and improve the genetic makeup of populations through selective human breeding

evolutionary perspective

examines how natural selection and adaptation explain human thoughts and behaviors, emphasizing traits that enhance survival and reproduction, passed down through generations

excitatory postsynaptic potential

a brief decrease in the difference in electrical charge across the membrane of a neuron that is caused by the transmission of a signal from a neighboring neuron across the synapse (specialized junction) separating them.

inhibitory postsynaptic potential

a brief increase in the difference in electrical charge across the membrane of a neuron that is caused by the transmission of a signal from a neighboring neuron across the synapse (specialized junction) separating them.

fight-or-flight

a pattern of physiological changes elicited by activity of the sympathetic nervous system in response to threatening or otherwise stressful situations that leads to mobilization of energy for physical activity

forebrain

the part of the brain that develops from the anterior section of the neural tube in the embryo, containing the cerebrum and the diencephalon.

fovea

a small depression in the central portion of the retina in which retinal cone cells are most concentrated and an image is focused most clearly.

ganglion cells

the only type of neuron in the retina that sends signals to the brain resulting from visual stimulation

gate control theory of pain

the hypothesis that the subjective experience of pain is modulated by large nerve fibers in the spinal cord that act as gates, such that pain is not the product of a simple transmission of stimulation from the skin or some internal organ to the brain

generalizability

the extent to which results or findings obtained from a sample are applicable to a broader population.

glands

an organ that secretes a substance for use by or discharge from the body

glial cells

non-neuronal cells that support and protect neurons, forming myelin, maintaining the brain environment, and playing a role in immune defense

gustation

the sense of taste.

hallucinogens

a false sensory perception that has a compelling sense of reality despite the absence of an external stimulus.

hempispheric specialization

refers to the idea that the two brain hemispheres (left and right) have different, specialized functions, with the left hemisphere generally dominant for language and the right for spatial reasoning and creativity

heredity

he transmission of traits from parents to their offspring.

heritability

the capacity to be inherited.

hindbrain

the posterior of three bulges that appear in the embryonic brain as it develops from the neural tube.

hippocampus

a seahorse-shaped part of the forebrain, in the basal medial region of the temporal lobe, that is important for declarative memory and learning

homeostasis

the regulation by an organism of all aspects of its internal environment, including body temperature, salt–water balance (see osmoregulation), acid–base balance (see hydrogen-ion concentration), and blood sugar level

adrenaline

a hormone released by the adrenal glands that plays a crucial role in the fight-or-flight response, preparing the body for stressful or dangerous situations. 

leptin

a protein, manufactured and secreted by fat cells, that may communicate to the brain the amount of body fat stored and may help to regulate food intake.

ghrelin

a peptide secreted by endocrine cells in the stomach that binds to growth hormone receptors in the hypothalamus and anterior pituitary, stimulating appetite and the release of growth hormone.

melatonin

an amine hormone, produced mainly by the pineal gland as a metabolic product of the neurotransmitter serotonin, that helps to regulate seasonal changes in physiology and may also influence puberty.

oxytocin

often referred to as the "love hormone" or "cuddle hormone" and is associated with social bonding, trust, and empathy, playing a role in behaviors like pair bonding, childbirth, and breastfeeding

hyperpolarization

an increase in the electric potential across the plasma membrane of a cell, especially a neuron, such that the inner surface of the membrane becomes more negative in relation to the outer surface.

hypothalamus

contains nuclei with primary control of the autonomic (involuntary) functions of the body.

4 F’s

fight, flight, freeze, and fawn

Independent variable

the variable in an experiment that is specifically manipulated or is observed to occur before the dependent, or outcome, variable, in order to assess its effect or influence

Dependent variable

the outcome that is observed to occur or change after the occurrence or variation of the independent variable in an experiment, or the effect that one wants to predict or explain in correlational research.

Interneurons

any neuron that is neither sensory nor motor but connects other neurons within the central nervous system

Ions

electrically charged particles (like sodium, potassium, calcium, and chloride) that play a crucial role in neural communication, specifically in the process of action potentials and resting potential. 

Just-noticeable difference

the smallest difference between two stimuli that can be consistently and accurately detected on 50% of trials

K complex

a brief, high-amplitude spike-and-rebound waveform recorded in the scalp electroencephalograph during sleep onset.

Kinesthesis

the sense that provides information through receptors in the muscles, tendons, and joints, enabling humans and other animals to control and coordinate their movements, including walking, talking, facial expressions, gestures, and posture.

Left hemisphere of the brain

the part of the brain concerned with sensation and perception, motor control, and higher level cognitive processes.

Right hemisphere of the brain

the part of the brain responsible for processing non-verbal information, spatial reasoning, and creative thinking, while also controlling the left side of the body

lesioning

any disruption of or damage to the normal structure or function of an organ or part of an organ due to injury, disease, or a surgical procedure.

limbic system

a loosely defined, widespread group of brain nuclei that innervate each other to form a network that is involved in autonomic and visceral processes and mechanisms of emotion, memory, and learning.