AP PSYCH UNIT 1

What does the Nature vs. Nurture debate study?

Whether behavior and traits are shaped more by genetics (nature) or environment and experience (nurture).

What is heritability (h²)?

The % of variation in a trait within a population due to genetics (0.0 = all environment, 1.0 = all genetics).

What did the Han Chinese vs. European hair color example show?

Han = low heritability (little genetic variation); Europeans = high heritability (large genetic variation).

What is evolutionary psychology?

Studies how traits and behaviors evolved to help ancestors survive and reproduce.

Define natural selection.

Traits that improve survival and reproduction are passed to offspring.

Define adaptation.

Species change over time to better fit their environment.

What is eugenics and who founded it?

“Improving” population by selective breeding; founded by Francis Galton (1883).

How was eugenics misused historically?

U.S. sterilization laws and Nazi “racial purification” through sterilization, euthanasia, and genocide.

What does behavior genetics study?

How genes and environment influence behavior.

Define environment.

All non-biological influences (family, culture, education, experiences).

Define heredity.

Passing genes from parents to offspring.

Define genes and genome.

Genes = units of heredity; Genome = complete set of genes.

What are monozygotic twins?

Identical twins—one fertilized egg splits; genetically identical.

What are dizygotic twins?

Fraternal twins—two eggs fertilized; genetically like siblings.

What did the Minnesota Twin Study find?

Genetics strongly influence personality, IQ, and health.

What did the Colorado Adoption Project show?

As children age, their IQ/personality resemble biological more than adoptive parents, showing genetic influence increases over time.

What is epigenetics?

Environmental factors turn genes “on” or “off” without changing DNA sequence.

What are the two main parts of the nervous system?

CNS (Brain + Spinal Cord) and PNS (all other nerves).

What is a neuron?

A nerve cell that receives, processes, and transmits information.

What do sensory (afferent) neurons do?

Carry messages to the brain; detect stimuli like light, sound, and touch.

What do motor (efferent) neurons do?

Carry messages from the brain to muscles; cause movement.

What do interneurons do?

Connect sensory and motor neurons inside the CNS.

What is a reflex arc?

Automatic response that travels through spinal cord without brain involvement.

What is the soma?

Cell body that contains the nucleus and nutrients.

What are dendrites?

Branch-like structures that receive signals.

What is the axon?

Long fiber that sends impulses away from the soma.

What is the myelin sheath?

Fatty insulation that speeds up neural signals; damaged in multiple sclerosis (MS).

What are axon terminals?

Ends of axon that release neurotransmitters.

What is the synapse?

Gap where one neuron passes information to another.

Define action potential.

Brief electrical impulse (firing) when stimulation reaches threshold.

What is the all-or-none principle?

Neurons fire completely or not at all.

What is the refractory period?

Time after firing when neuron can’t fire again until reset.

What is resting potential?

The negative charge inside a neuron at rest (~–70 mV).

What is reuptake?

Reabsorption of neurotransmitters by the sending neuron.

What are glial cells?

Support cells that form myelin, clean waste, provide nutrients, and repair neurons.

What do neurotransmitters do?

Chemical messengers that transmit signals between neurons.

What are excitatory vs. inhibitory neurotransmitters?

Excitatory increase firing; inhibitory decrease firing.

What is an agonist?

Drug that mimics or increases neurotransmitter action.

What is an antagonist?

Drug that blocks or decreases neurotransmitter action.

What does acetylcholine (ACh) do?

Enables muscle action, learning, and memory; low ACh causes Alzheimer’s or myasthenia gravis.

What does serotonin do?

Regulates mood, sleep, and hunger; low levels cause depression.

What does dopamine do?

Controls movement, motivation, learning, emotion; low = Parkinson’s, high = schizophrenia or addiction.

What does norepinephrine do?

Increases alertness and arousal; low levels cause depression.

What does GABA do?

Major inhibitory neurotransmitter; low levels cause seizures, tremors, and insomnia.

What does glutamate do?

Major excitatory neurotransmitter; high levels cause migraines and seizures.

What do endorphins do?

Natural painkillers linked to pleasure; opioids reduce natural production.

What does Substance P do?

Involved in pain perception and immune response.

What is the endocrine system?

Body’s slow chemical communication system using hormones via bloodstream.

What is the pituitary gland?

“Master gland” controlled by hypothalamus; releases growth hormone and vasopressin.

What does oxytocin do?

“Love hormone”; promotes bonding, trust, and uterine contractions.

What does melatonin do?

Regulates sleep-wake cycles; produced by pineal gland.

What does leptin do?

Signals fullness and energy sufficiency to the brain.

What does ghrelin do?

Triggers hunger when stomach is empty.

What are psychoactive drugs?

Chemicals that alter brain function and change mood or perception.

What is tolerance?

Reduced effect with regular use, requiring larger doses.

What is addiction?

Compulsive use despite harmful consequences.

What is withdrawal?

Discomfort or distress after stopping a drug.

What are the effects of alcohol?

Depressant; relaxation then memory loss, impaired reaction, organ damage.

What are the effects of opioids like heroin or oxycodone?

Mimic endorphins; cause euphoria and high addiction; depress physiology.

What are the effects of marijuana (THC)?

Mild hallucinogen; relaxation, altered time perception, impaired learning and memory.

What does the Somatic Nervous System control?

Voluntary muscle movement and sensory input.

What does the Autonomic Nervous System control?

Involuntary functions like heartbeat, digestion, and glands.

What does the Sympathetic Division do?

“Fight or flight”; increases heart rate, breathing, decreases digestion.

What does the Parasympathetic Division do?

“Rest and digest”; slows heart rate and restores energy.

What are case studies used for?

Study effects of brain damage on behavior (e.g., Phineas Gage).

What are lesion studies?

Studying brain regions by observing effects of damage or removal.

Which brain imaging techniques are on the exam?

EEG and fMRI.

What does an EEG measure?

Electrical activity (brain waves); used for sleep and seizure studies.

What does an fMRI measure?

Blood and oxygen flow to show brain activity and function.

What makes up the central nervous system (CNS)?

Brain and spinal cord.

What does the brainstem control?

Vital life functions like heartbeat and breathing.

What does the cerebellum do?

Balance, coordination, and procedural (muscle) memory.

What is the cerebrum?

85% of brain; four lobes, two hemispheres, and cerebral cortex for higher thinking.

What does the corpus callosum do?

Connects left and right hemispheres for communication.

What does the frontal lobe do?

Thinking, planning, speech, voluntary movement; includes Motor Cortex & Broca’s Area.

What does the parietal lobe do?

Processes touch and body position; includes Somatosensory Cortex.

What does the occipital lobe do?

Vision; includes Visual Cortex.

What does the temporal lobe do?

Hearing and memory; includes Auditory Cortex & Wernicke’s Area.

Where is Broca’s Area and what does it control?

Left frontal lobe; speech production.

What are symptoms of Broca’s Aphasia?

Can understand but struggle to speak; aware of problem.

Where is Wernicke’s Area and what does it control?

Left temporal lobe; language comprehension.

What are symptoms of Wernicke’s Aphasia?

Speak fluently but speech makes no sense; unaware of problem.

What does the limbic system regulate?

Emotions, motivation, reward, and memory formation.

What does the thalamus do?

Relays sensory info (except smell) to the cerebral cortex.

What does the hippocampus do?

Forms new memories; damage causes anterograde amnesia.

What does the amygdala do?

Controls emotion, fear, and aggression.

What does the hypothalamus do?

Maintains homeostasis; controls hunger, thirst, body temp, and sex drive; regulates pituitary gland.

What hormones are linked to hypothalamus hunger control?

Ghrelin (hunger) and Leptin (fullness).

What is the Reticular Activating System (RAS)?

Network in brainstem regulating arousal, attention, and sleep-wake cycle; damage can cause coma.

What are association areas?

Regions not involved in movement or sensation; handle thinking, learning, memory, and speech.

What is brain lateralization?

Each hemisphere specializes: left = language/logical; right = spatial/facial recognition.

What is prosopagnosia?

Face blindness from right fusiform gyrus damage.

What is neurogenesis?

Formation of new neurons.

What is brain plasticity (neuroplasticity)?

Brain’s ability to form new connections and reorganize after learning or injury.

Who researched split-brain and hemisphere specialization?

Roger Sperry and Paul Gazzaniga, studying patients after corpus callosum surgery.

Which two neuroimaging techniques are part of the AP curriculum?

EEG and fMRI.