AP Psychology Unit 1: Biological Bases of Behavior

Heredity

The passing of traits from parents to offspring.

Nature

The influence of genetics on behavior.

Nurture

The influence of the environment on behavior.

Genetic predisposition

A genetic tendency to develop certain traits or disorders.

Evolutionary perspective

A perspective focusing on how evolution shapes behavior.

Natural selection

The process by which traits that enhance survival are passed on.

Eugenics

The scientifically erroneous and immoral theory of “racial improvement” and “planned breeding,” which gained popularity during the early 20th century.

Twin studies

Studies comparing similarities between identical and fraternal twins.

Family studies

Studies comparing similarities among family members.

Adoption studies

Studies comparing adopted children to their biological and adoptive families.

Central nervous system

The part of the nervous system consisting of the brain and spinal cord.

Peripheral nervous system

The part of the nervous system outside the brain and spinal cord.

Autonomic nervous system

The part of the peripheral nervous system controlling involuntary actions.

Sympathetic nervous system

The division of the autonomic nervous system that activates fight-or-flight responses.

Parasympathetic nervous system

The division of the autonomic nervous system that calms the body.

Somatic nervous system

The part of the peripheral nervous system controlling voluntary movements.

Neurons

Specialized cells transmitting electrical and chemical signals.

Glial cells

Supportive cells assisting neurons.

Reflex arc

The neural pathway consisting of a sensory neuron, an interneuron, and a motor neuron that transmits signals quickly to produce an automatic response.

Sensory neurons

Neurons transmitting sensory information to the brain.

Motor neurons

Neurons transmitting signals from the brain to muscles.

Interneurons

Neurons communicating between sensory and motor neurons.

Neural transmission

The process of transmitting a neural signal.

Action potential

The brief electrical charge that travels down the axon of a neuron, triggering the release of neurotransmitters at the synapse.

All-or-nothing principle

The principle that a neuron fires fully or not at all.

Depolarization

The change in a neuron's charge that initiates an action potential.

Refractory period

The period when a neuron cannot fire after an action potential.

Resting potential

The stable, negative charge of an inactive neuron.

Reuptake

The reabsorption of neurotransmitters by a neuron.

Threshold

The level of stimulation required to trigger an action potential.

Multiple sclerosis

A disease damaging the myelin sheath around neurons.

Myasthenia gravis

A disorder causing muscle weakness due to damaged nerve receptors.

Excitatory neurotransmitters

Neurotransmitters that increase the likelihood of a neuron firing.

Inhibitory neurotransmitters

Neurotransmitters that decrease the likelihood of a neuron firing.

Dopamine

A neurotransmitter involved in movement, motivation, and reward.

Serotonin

A neurotransmitter regulating mood, appetite, and sleep.

Norepinephrine

A neurotransmitter involved in alertness and arousal.

Glutamate

The main excitatory neurotransmitter in the brain.

GABA

The main inhibitory neurotransmitter in the brain.

Endorphins

Neurotransmitters that reduce pain and enhance pleasure.

Substance p

A neurotransmitter involved in pain perception.

Acetylcholine

A neurotransmitter involved in muscle action and memory.

Hormones

Chemical messengers released by glands.

Adrenaline

A hormone that increases heart rate and energy.

Leptin

A hormone regulating appetite and energy balance.

Ghrelin

A hormone stimulating hunger.

Melatonin

A hormone regulating sleep-wake cycles.

Oxytocin

A hormone associated with bonding and social behavior.

Psychoactive drugs

Drugs affecting the brain and behavior.

Agonists

Substances that enhance the action of a neurotransmitter.

Antagonists

Substances that block the action of a neurotransmitter.

Reuptake inhibitors

Drugs that inhibit the reabsorption of neurotransmitters.

Stimulants

Drugs that increase central nervous system activity.

Caffeine

A stimulant found in coffee and tea.

Cocaine

A powerful stimulant derived from coca leaves.

Depressants

Drugs that decrease central nervous system activity.

Alcohol

A depressant commonly consumed in beverages.

Hallucinogens

Drugs causing hallucinations and altered perceptions.

Marijuana

A psychoactive drug derived from the cannabis plant.

Opioids

Drugs derived from opium that relieve pain.

Heroin

A potent opioid causing euphoria and addiction.

Tolerance

The need for increasing amounts of a substance to achieve the same effect.

Addiction

A compulsive craving for and use of a substance.

Withdrawal

Symptoms experienced when stopping a substance.

Brain stem

The lower part of the brain connecting to the spinal cord.

Medulla

The part of the brain controlling vital functions like breathing.

Reticular activating system

A network controlling arousal and attention.

Reward center

A brain region involved in processing rewards.

Cerebellum

The part of the brain involved in coordination and balance.

Cerebral cortex

The outer layer of the brain involved in complex functions.

Limbic system

A group of brain structures involved in emotion and memory.

Thalamus

The brain's relay station for sensory information.

Hypothalamus

A brain region regulating homeostasis and basic drives.

Pituitary gland

A gland controlling growth and other endocrine glands.

Hippocampus

A brain structure involved in forming new memories.

Amygdala

A brain region involved in processing emotions.

Corpus callosum

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

Occipital lobes

The lobes at the back of the brain involved in vision.

Temporal lobes

The lobes on the sides of the brain involved in hearing and memory.

Parietal lobes

The lobes at the top of the brain involved in sensory processing.

Association areas

Regions of the brain involved in integrating information.

Somatosensory cortex

A brain area processing touch and body position.

Frontal lobes

The lobes at the front of the brain involved in decision-making and movement.

Linguistic processing

The process of understanding and producing language.

Higher-order thinking

Complex mental activities such as thinking, reasoning, and planning.

Executive functioning

Processes involved in managing and regulating behavior.

Prefrontal cortex

The front part of the frontal lobes involved in planning and decision-making.

Motor cortex

A brain region controlling voluntary movements.

Split brain research

Research on the functions of the brain's hemispheres.

Hemispheric specialization

The specialization of the brain's hemispheres for different functions.

Broca's area

A brain area involved in speech production.

Wernicke's area

A brain area involved in language comprehension.

Aphasia (Broca's and Wernicke's)

Language disorders due to damage in specific brain areas.

Contralateral hemispheric organization

The organization where each hemisphere controls the opposite side of the body.

Plasticity

The brain's ability to change and adapt.

EEG

A technique for recording electrical activity in the brain.

fMRI

A brain imaging technique showing brain activity.

Lesioning

The removal or destruction of brain tissue.

Consciousness

The state of being awake and aware.

Circadian rhythm (sleep/wake cycle)

The body's natural 24-hour cycle.