AP Psych Unit 1

Biological Basis of Behavior

Heredity

the genetic transmission of traits from parents to offspring

Nature

the influence of genetics on behavior and traits

Nurture

the influence of environment and experience on behavior

Genetic predisposition

an inherited tendency to develop certain traits or disorders

Evolutionary perspective

view that behavior is shaped by natural selection

Natural selection

process by which traits aiding survival are passed on

Eugenics

movement aimed at improving genetics through selective breeding

Twin studies

research comparing identical and fraternal twins

Family studies

research examining traits across generations

Adoption studies

research comparing adopted children to biological and adoptive parents

Central nervous system

brain and spinal cord

Brain and spinal cord

main control center of the nervous system

Peripheral nervous system

nerves connecting CNS to the body

Autonomic nervous system

controls involuntary bodily functions

Sympathetic nervous system

arouses body for action (fight or flight)

Parasympathetic nervous system

calms body and conserves energy

Somatic nervous system

controls voluntary muscle movement

Neurons

nerve cells that transmit information

Glial cells

support and nourish neurons

Reflex arc

automatic response pathway involving spinal cord

Sensory neurons

carry information to the CNS

Motor neurons

carry commands from CNS to muscles

Interneurons

connect sensory and motor neurons

Neural transmission

communication between neurons

Action potential

electrical impulse traveling down a neuron

All-or-nothing principle

neuron fires fully or not at all

Depolarization

neuron becomes positively charged during firing

Refractory period

brief time when neuron cannot fire again

Resting potential

neuron’s inactive charge state

Reuptake

neurotransmitters reabsorbed by sending neuron

Threshold

minimum stimulation needed to fire a neuron

Multiple sclerosis

disease destroying myelin sheath

Myasthenic gravis

autoimmune disorder causing muscle weakness

Excitatory neurotransmitters

increase likelihood of neuron firing

Inhibitory neurotransmitters

decrease likelihood of neuron firing

Dopamine

influences movement

Serotonin

regulates mood

Norepinephrine

controls alertness and arousal

GABA

main inhibitory neurotransmitter

Endorphins

reduce pain and increase pleasure

Substance P

involved in pain perception

Acetylcholine

enables muscle movement and memory

Hormones

chemical messengers released by endocrine glands

Adrenaline

hormone that increases arousal and stress response

Leptin

hormone signaling fullness

Ghrelin

hormone that stimulates hunger

Melatonin

hormone regulating sleep

Oxytocin

hormone involved in bonding

Psychoactive drugs

substances affecting brain and behavior

Agonists

increase neurotransmitter action

Antagonists

block neurotransmitter action

Reuptake inhibitors

prevent neurotransmitter reabsorption

Stimulants

increase nervous system activity

Caffeine

stimulant increasing alertness

Cocaine

stimulant causing dopamine surge

Depressants

slow nervous system activity

Alcohol

depressant impairing coordination

Hallucinogens

distort perception and reality

Marijuana

mild hallucinogen affecting perception

Opioids

pain-reducing drugs

Heroin

addictive opioid drug

Tolerance

need for increased dose

Addiction

compulsive substance use

Withdrawal

symptoms after stopping drug use

Brain stem

controls basic life functions

Medulla

regulates breathing and heart rate

Reticular activating system

controls alertness

Reward center

brain areas linked to pleasure

Cerebellum

coordinates balance and movement

Cerebral cortex

outer brain layer for thinking

Limbic system

emotion and memory system

Thalamus

sensory relay station

Hypothalamus

regulates hunger

Pituitary gland

master endocrine gland

Hippocampus

forms new memories

Amygdala

processes emotion and fear

Corpus callosum

connects brain hemispheres

Occipital lobes

process vision

Temporal lobes

process hearing and language

Parietal lobes

process touch and spatial awareness

Association areas

integrate information

Somatosensory cortex

receives touch information

Frontal lobes

decision-making and personality

Unilateral processing

one hemisphere handles certain tasks

Right-brain thinking

creativity and spatial tasks

Executive functioning

planning and impulse control

Prefrontal cortex

judgment and decision-making

Motor cortex

controls voluntary movement

Split-brain operation

severing corpus callosum

Hemispheric specialization

each hemisphere has specialized functions

Broca’s area

speech production

Wernicke’s area

language comprehension

Aphasia (Broca’s and Wernicke’s)

language impairment

Contralateral hemispheric organization

brain controls opposite body side

Plasticity

brain’s ability to change

EEG

records brain electrical activity

fMRI

shows brain activity via blood flow

Lesioning

studying brain by damaging areas

Consciousness

awareness of self and environment

Circadian rhythm

24-hour biological clock