All AP Psychology Terms (2024-2025)

nature

the influence of our inherited characteristics on our personality, physical growth, intellectual growth, and social interactions

nurture

environment

Heredity

Passing of traits from parents to offspring

Epigenetics

the study of environmental influences on gene expression that occur without a DNA change

Heritability

The proportion of variation among individuals that we can attribute to genes. The heritability of a trait may vary, depending on the range of populations and environments studied.

peripheral nervous system

the sensory and motor neurons that connect the central nervous system to the rest of the body

central nervous system

consists of the brain and spinal cord

autonomic nervous system

the part of the peripheral nervous system that controls the glands and the muscles of the internal organs (such as the heart). Its sympathetic division arouses; its parasympathetic division calms.

somatic nervous system

the division of the peripheral nervous system that controls the body's skeletal muscles

Neuron

a nerve cell; the basic building block of the nervous system

afferent neurons

neurons that take information from the senses to the brain

efferent neurons

Nerve cells that conduct impulses away from the central nervous system

Interneurons

neurons within the brain and spinal cord that communicate internally and intervene between the sensory inputs and motor outputs

glial cells

cells in the nervous system that support, nourish, and protect neurons

Dendrites

Branchlike parts of a neuron that are specialized to receive information.

Soma

cell body

Axon

the extension of a neuron, ending in branching terminal fibers, through which messages pass to other neurons or to muscles or glands

myelin sheath

covers the axon of some neurons and helps speed neural impulses

axon terminal

The endpoint of a neuron where neurotransmitters are stored

action potential

a neural impulse; a brief electrical charge that travels down an axon

refractory period

the time following an action potential during which a new action potential cannot be initiated

threshold

the level of stimulation required to trigger a neural impulse

all-or-nothing response

a neuron's reaction of either firing at full strength, or not firing.

depolarization

The process during the action potential when sodium is rushing into the cell causing the interior to become more positive.

Synapse (synaptic gap)

microscopic fluid-filled space between the axon terminal of one cell and the dendrites or surface of the next cell

Neurotransmitters

chemical messengers that cross the synaptic gaps between neurons

Reuptake

process by which neurotransmitters are taken back into the synaptic vesicles

dopamine

influences movement, learning, attention, and emotion

serotonin

Affects mood, hunger, sleep, and arousal

Norepinephrine

A neurotransmitter involved in arousal, as well as in learning and mood regulation

Acetylcholine (ACh)

enables muscle action, learning, and memory

Gamma-Aminobutyric (GABA)

neurotransmitter at most inhibitory synapses in the brain

Glutamate

A major excitatory neurotransmitter; involved in memory

substance P

A neurotransmitter that is involved in the transmission of pain messages to the brain.

endorphins

"morphine within"--natural, opiatelike neurotransmitters linked to pain control and to pleasure.

Alcohol and neurotransmitters

-stimulates GABA receptors, which may be responsible for reducing tension

-increases levels of dopamine and seratonin, may account for pleasurable feelings

-inhibits glutamate receptors, which may cause the cognitive effects of alcohol intoxiation like slurred speech and memory loss

Heroin and neurotransmitters

Turns off dopamine inhibition.

Increased dopamine causes immediate feelings of sedation and well-being.

Marijuana and neurotransmitters

THC (active chemical in marijuana) mimics anandamide; binds to cannabinoid receptors (turn off release of inhibitory receptors). Inhibition turned off and dopamine released.

Ecstasy and neurotransmitters

Ecstasy alters the serotonin transporter that transports serotonin into the cell, it becomes 'confused' and starts to do its job in reverse. The transporter starts transporting serotonin outside of the cell. The excess serotonin becomes trapped in the synaptic cleft, it binds again and again to the receptors, overstimulating the cell.

Meth and neurotransmitters

norepinephrine and dopamine

LSD and neurotransmitters

LSD acts almost exclusively on serotonin neurons. LSD chemically resembles serotonin and elicits its effect by binding to serotonin receptors.

Cocaine and Neurotransmitters

This drug blocks reuptake of dopamine, serotonin, and norepinephrine. These extra neurotransmitter molecules remain in the synapse, producing an euphoric rush.

endocrine system

the body's "slow" chemical communication system; a set of glands that secrete hormones into the bloodstream

adrenaline

A hormone released into the bloodstream in response to physical or mental stress

leptin

A hormone produced by adipose (fat) cells that acts as a satiety factor in regulating appetite.

Ghrelin

A hunger-arousing hormone secreted by an empty stomach

Melatonin

A hormone manufactured by the pineal gland that produces sleepiness.

Oxytocin

a hormone released by the pituitary gland that causes increased contraction of the uterus during labor and stimulates the ejection of milk into the ducts of the breasts. "Love" or "attachment" hormone

CT Scan

a series of x-ray photographs taken from different angles and combined by computer into a composite representation of a slice through the body

MRI (magnetic resonance imaging)

a technique that uses magnetic fields and radio waves to produce computer-generated images of soft tissue. MRI scans show brain anatomy.

EEG (electroencephalogram)

An amplified recording of the waves of electrical activity that sweep across the brain's surface. These waves are measured by electrodes placed on the scalp.

PET Scan

a visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given task

fMRI

A technique for revealing blood flow and, therefore, brain activity by comparing successive MRI scans.

contralateral control

each hemisphere of the brain controls the opposite side of the body

corpus callosum

the large band of neural fibers connecting the two brain hemispheres and carrying messages between them

split brain

a condition resulting from surgery that isolates the brain's two hemispheres by cutting the fibers (mainly those of the corpus callosum) connecting them

frontal lobe

A region of the cerebral cortex that has specialized areas for movement, abstract thinking, planning, memory, and judgement

parietal lobe

A region of the cerebral cortex whose functions include processing information about touch.

Temporal lobe

A region of the cerebral cortex responsible for hearing and language.

Occipital lobe

A region of the cerebral cortex that processes visual information

Broca's Area

Controls language expression - an area of the frontal lobe, usually in the left hemisphere, that directs the muscle movements involved in speech.

Wernicke's area

controls language reception - a brain area involved in language comprehension and expression; usually in the left temporal lobe

Prosopagnosia

inability to recognize faces

aphasia

impairment of language, usually caused by left hemisphere damage either to Broca's area (impairing speaking) or to Wernicke's area (impairing understanding).

limbic system

neural system (including the hippocampus, amygdala, and hypothalamus) located below the cerebral hemispheres; associated with emotions and drives.

Hypothalamus

A neural structure lying below the thalamus; it directs several maintenance activities (eating, drinking, body temperature), helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward.

Amygdala

A limbic system structure involved in memory and emotion, particularly fear and aggression.

Hippocampus

A neural center located in the limbic system that helps process explicit memories for storage.

Medulla

the base of the brainstem; controls heartbeat and breathing

Reticular Formation

a nerve network in the brainstem that plays an important role in controlling arousal

Pons

sleep and arousal

Thalamus

the brain's sensory switchboard, located on top of the brainstem; it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla

Cerebellum

the "little brain" at the rear of the brainstem; functions include processing sensory input and coordinating movement output and balance

basal ganglia

a set of subcortical structures that directs intentional movements

olfactory bulb

the brain center for smell, located below the frontal lobes

circadian rhythm

the biological clock; regular bodily rhythms that occur on a 24-hour cycle

NREM stage 1 sleep

relaxation begins; EEG shows alpha waves; arousal is easy; hypnogogic sensations

NREM Stage 2 Sleep

sleep spindles and mixed EEG activity

NREM Stage 3 Sleep

(slow-wave, deepest sleep) progressively more delta waves

REM stage

stands for rapid eye movement. majority of dreams happen in REM sleep, 25% of night's sleep is spent in REM, sexual arousal occurs and body muscle become paralyzed

Narcolepsy

A sleep disorder characterized by uncontrollable sleep attacks. The sufferer may lapse directly into REM sleep, often at inopportune times.

Sleep Apnea

a sleep disorder characterized by temporary cessations of breathing during sleep and repeated momentary awakenings

Night Terrors

a sleep disorder characterized by high arousal and an appearance of being terrified; unlike nightmares, night terrors occur during Stage 3 sleep, within two or three hours of falling asleep, and are seldom remembered

Insomnia

recurring problems in falling or staying asleep

REM Rebound

the tendency for REM sleep to increase following REM sleep deprivation (created by repeated awakenings during REM sleep)

kinesthetic sense

sense of the location of body parts in relation to the ground and each other

vestibular sense

the sense of body movement and position, including the sense of balance

Synesthesia

when one kind of sensory stimulus evokes the subjective experience of another

absolute threshold

the minimum stimulation needed to detect a particular stimulus 50 percent of the time

difference threshold

the minimum difference between two stimuli required for detection 50 percent of the time

Weber's law

the principle that, to be perceived as different, two stimuli must differ by a constant minimum percentage (rather than a constant amount)

Below Threshold

subliminal

sensory adaptation

tendency of sensory receptor cells to become less responsive to a stimulus that is unchanging

Transduction

conversion of one form of energy into another. In sensation, the transforming of stimulus energies, such as sights, sounds, and smells, into neural impulses our brains can interpret.

cornea

The clear tissue that covers the front of the eye

pupil

the adjustable opening in the center of the eye through which light enters

lens

the transparent structure behind the pupil that changes shape to help focus images on the retina