AP Psychology Unit 1 Terms

Nature–nurture issue

The debate over whether behavior comes from genetics or environment.

Charles Darwin

Scientist who developed the theory of evolution by natural selection.

Natural selection

The process where traits that help survival and reproduction become more common.

Evolutionary psychology

The study of how evolution may explain behavior and mental processes.

Behavior genetics

The study of how genes and environment influence behavior.

Mutation

A random change in an organism's DNA.

Environment

All outside influences that affect a person's development and behavior.

Heredity

The passing of traits from parents to offspring through genes.

Genes

DNA segments that control inherited traits.

Genome

All of an organism's genetic material.

Identical (monozygotic) twins

Twins who develop from one fertilized egg and have nearly identical genes.

Fraternal (dizygotic) twins

Twins who develop from two separate eggs and share about 50% of their genes.

Interaction

The way genes and environment work together to influence behavior.

Epigenetics

The study of how environment can affect gene expression without changing DNA.

Nervous system

The body's system for communicating through electrical and chemical signals.

Central nervous system (CNS)

The brain and spinal cord.

Peripheral nervous system (PNS)

All nerves outside the brain and spinal cord.

Nerves

Bundles of fibers that carry messages throughout the body.

Sensory (afferent) neurons

Neurons that carry information from the senses to the CNS.

Motor (efferent) neurons

Neurons that carry commands from the CNS to muscles and glands.

Interneurons

Neurons that connect sensory and motor neurons within the CNS.

Somatic nervous system

Controls voluntary movement of skeletal muscles.

Autonomic nervous system (ANS)

Controls automatic body functions like heartbeat and digestion.

Sympathetic nervous system

Activates the body during stress or emergencies.

Parasympathetic nervous system

Calms the body and conserves energy after stress.

Reflex

An automatic, rapid response to a stimulus.

Neuron

A nerve cell that sends and receives information.

Cell body

The part of a neuron containing the nucleus and keeping the cell alive.

Dendrites

Branches that receive messages from other neurons.

Axon

The part of a neuron that sends messages to other cells.

Myelin sheath

Fatty covering that speeds up neural signals along the axon.

Glial cells (glia)

Cells that support, protect, and nourish neurons.

Action potential

A neural impulse that travels down an axon.

Threshold

The minimum stimulation needed to trigger an action potential.

Refractory period

A short period when a neuron cannot fire again normally.

All-or-none response

A neuron either fires completely or does not fire at all.

Synapse

The tiny gap between neurons where communication occurs.

Neurotransmitters

Chemicals that carry messages across synapses.

Reuptake

The process of a sending neuron taking neurotransmitters back in.

Endorphins

Natural chemicals that reduce pain and can create feelings of pleasure.

Agonist

A chemical that increases or imitates a neurotransmitter's effects.

Antagonist

A chemical that blocks or reduces a neurotransmitter's effects.

Endocrine system

The body's system of glands that releases hormones into the blood.

Hormones

Chemical messengers released by endocrine glands.

Psychoactive drug

A substance that changes mood, thinking, or behavior.

Substance use disorder

A pattern of continued drug use despite harmful effects.

Depressants

Drugs that slow nervous system activity.

Tolerance

Needing more of a drug to get the same effect.

Addiction

A strong need to continue using a substance despite harmful effects.

Withdrawal

Unpleasant effects after stopping a drug.

Barbiturates

Depressant drugs that reduce nervous system activity.

Opioids

Drugs that reduce pain and can produce relaxation.

Stimulants

Drugs that increase nervous system activity.

Hallucinogens

Drugs that cause changes in perception and sensory experiences.

Near-death experience

An unusual psychological experience reported by some people close to death.

Biological psychology

The study of how biology affects behavior and mental processes.

Biopsychosocial approach

Explaining behavior using biological, psychological, and social factors.

Levels of analysis

Different ways of studying behavior, from biological to psychological to social.

Neuroplasticity

The brain's ability to change and reorganize itself.

Lesion

Damaged or destroyed brain tissue.

EEG

A device that records electrical activity in the brain.

MEG

A device that measures magnetic fields produced by brain activity.

CT scan

An imaging method that uses X-rays to create detailed brain images.

PET scan

A scan that shows brain activity by tracking radioactive glucose.

MRI

An imaging technique that uses magnets to create detailed brain images.

fMRI

An MRI that shows brain activity by tracking blood flow.

Hindbrain

The lower brain area involved in basic survival functions.

Midbrain

The brain region involved in movement, vision, hearing, and alertness.

Forebrain

The largest brain region involved in thinking, emotion, and sensory processing.

Brainstem

The structure connecting the brain to the spinal cord and controlling basic functions.

Medulla

Controls automatic functions such as breathing and heartbeat.

Thalamus

The brain's sensory relay station, except for smell.

Reticular formation

A network involved in alertness and arousal.

Cerebellum

Controls balance, coordination, and fine motor movement.

Limbic system

A group of structures involved in emotion, motivation, and memory.

Amygdala

Helps process emotions, especially fear and aggression.

Hypothalamus

Controls hunger, thirst, body temperature, and other basic drives.

Hippocampus

Important for forming new memories.

Cerebral cortex

The brain's outer layer involved in complex thinking and processing.

Frontal lobes

Involved in planning, judgment, decision-making, and movement.

Parietal lobes

Process touch and information about body position.

Occipital lobes

Process visual information.

Temporal lobes

Process hearing, language, and memory.

Motor cortex

Controls voluntary muscle movements.

Somatosensory cortex

Processes touch and body sensations.

Association areas

Areas of the cortex involved in higher-level thinking and connecting information.

Neurogenesis

The creation of new neurons.

Corpus callosum

A bundle of fibers connecting the brain's two hemispheres.

Roger Sperry

Scientist who studied split-brain patients.

Michael Gazzaniga

Neuroscientist known for research on split-brain patients.

Split brain

A condition where the corpus callosum has been cut or damaged.

Consciousness

Awareness of yourself and your surroundings.

Cognitive neuroscience

The study of how brain activity relates to thinking and mental processes.

Dual processing

The brain processing information consciously and unconsciously at the same time.

Blindsight

Being able to respond to visual information without consciously seeing it.

Parallel processing

Processing many aspects of information at the same time.

Sequential processing

Processing information one step at a time.

Sleep

A natural state of reduced awareness and activity.

Circadian rhythm

The body's roughly 24-hour biological clock.

REM sleep

A sleep stage with rapid eye movements and vivid dreaming.