AP Psych Semester 1 || Units 2 - 5

Heredity

The genetic transfer of characteristics from parents to offspring.

Environmental factors

External influences such as education, family, and culture that shape development.

Evolutionary perspective

Study of how natural selection of traits has promoted the survival of genes.

Eugenics

The practice of trying to improve the human race by encouraging/discouraging reproduction.

Twin studies

Research comparing identical vs. fraternal twins to determine heritability.

Family studies

Examining blood relatives to see how much they resemble one another on traits.

Adoption studies

Comparing adopted children to biological and adoptive parents to weigh nature vs. nurture.

Central Nervous System (CNS)

The brain and the spinal cord.

Peripheral Nervous System (PNS)

Sensory and motor neurons that connect the CNS to the rest of the body.

Autonomic NS

Controls involuntary functions like heart rate and digestion.

Somatic NS

Controls voluntary movements of skeletal muscles.

Glial cells

Cells that support, nourish, and protect neurons; they also create myelin.

Reflex arc

A simple neural pathway for automatic response (sensory -> interneuron -> motor).

All-or-nothing principle

A neuron either fires at full strength or not at all.

Depolarization

Process during action potential where sodium rushes in, making the cell less negative.

Refractory period

A brief resting pause after a neuron has fired where it cannot fire again.

Resting potential

The negative-inside/positive-outside state of a neuron when it is not firing.

Reuptake

The reabsorption of excess neurotransmitters by the sending neuron.

Threshold

The minimum level of stimulation required to trigger a neural impulse.

Multiple Sclerosis

A disease where the myelin sheath is destroyed, slowing neural communication.

Myasthenia Gravis

Condition causing muscle weakness due to broken communication between nerves and muscles.

Dopamine

Influences movement, learning, attention, and emotion; linked to schizophrenia.

Serotonin

Affects mood, hunger, sleep, and arousal; low levels linked to depression.

Norepinephrine

Helps control alertness and arousal; part of "fight or flight."

Glutamate

A major excitatory neurotransmitter involved in memory.

GABA

A major inhibitory neurotransmitter that helps calm neural activity.

Endorphins

Natural, opiate-like neurotransmitters linked to pain control and pleasure.

Substance P

A neurotransmitter involved in the transmission of pain messages.

Acetylcholine (ACh)

Enables muscle action, learning, and memory.

Agonists

Molecules that increase a neurotransmitter's action by mimicking it.

Antagonists

Molecules that inhibit or block a neurotransmitter's action.

Reuptake inhibitors

Drugs (like SSRIs) that prevent reuptake to keep neurotransmitters in the synapse.

Stimulants

Drugs that excite neural activity and speed up body functions (e.g., caffeine).

Depressants

Drugs that reduce neural activity and slow body functions (e.g., alcohol).

Hallucinogens

Drugs that distort perceptions and evoke sensory images (e.g., LSD).

Opioids

Drugs that depress neural activity and temporarily lessen pain/anxiety (e.g., heroin).

Tolerance

The diminishing effect with regular use of the same dose of a drug.

Addiction

Compulsive craving of drugs or behaviors despite adverse consequences.

Withdrawal

The discomfort and distress following the discontinuation of an addictive drug.

Brainstem

The oldest part of the brain; responsible for automatic survival functions.

Medulla

Base of the brainstem; controls heartbeat and breathing.

Reticular Activating System (RAS)

Nerve network in the brainstem that controls arousal and alertness.

Cerebellum

The "little brain"; coordinates movement, balance, and procedural memory.

Cerebral cortex

The intricate fabric of interconnected neural cells covering the hemispheres.

Limbic System

Neural system (thalamus, amygdala, etc.) associated with emotions and drives.

Thalamus

The brain's sensory control center for all senses except smell.

Hypothalamus

Directs maintenance (eating, temp) and governs the endocrine system.

Pituitary gland

The "master gland" of the endocrine system; regulated by the hypothalamus.

Hippocampus

A neural center that helps process explicit memories for storage.

Amygdala

Two lima-bean-sized neural clusters linked to fear and aggression.

Corpus callosum

Large band of neural fibers connecting the two brain hemispheres.

Frontal lobe

Involved in speaking, muscle movements, and making plans/judgments.

Motor cortex

Area at the rear of frontal lobes that controls voluntary movements.

Parietal lobe

Receives sensory input for touch and body position.

Somatosensory cortex

Registers and processes body touch and movement sensations.

Occipital lobe

Includes areas that receive information from the visual fields.

Temporal lobe

Includes auditory areas receiving information from the opposite ear.

[Image of the lobes of the human brain]

Split-brain research

Studying patients with a severed corpus callosum to isolate hemisphere functions.

Broca’s area

Controls language expression and speech production (left frontal lobe).

Wernicke’s area

Controls language reception and comprehension (left temporal lobe).

Aphasia

Impairment of language usually caused by left hemisphere damage.

Brain plasticity

The brain's ability to reorganize after damage or build new pathways.

EEG

Recording of the waves of electrical activity sweeping across the brain's surface.

Adrenaline

Hormone (epinephrine) that triggers the "fight or flight" response.

Melatonin

Hormone that regulates sleep-wake cycles.

Oxytocin

Hormone linked to social bonding, trust, and romantic love.

Circadian rhythm

The biological clock; regular bodily rhythms on a 24-hour cycle.

NREM sleep

Non-rapid eye movement sleep; Stages 1-3.

Hypnagogic sensations

Bizarre experiences (like falling) while transitioning into sleep.

REM sleep

Rapid eye movement sleep; vivid dreams occur; "paradoxical sleep."

REM rebound

Increased REM sleep following REM sleep deprivation.

Activation-synthesis

Theory that dreams are the brain's attempt to synthesize random neural activity.

Consolidation theory

Theory that dreams help store the day's experiences in memory.

Insomnia

Recurring problems in falling or staying asleep.

Narcolepsy

Sleep disorder characterized by uncontrollable sleep attacks.

Sensation

Process by which sensory receptors receive stimulus energies from the environment.

Absolute threshold

Minimum stimulation needed to detect a stimulus 50% of the time.

Transduction

Conversion of one form of energy (light/sound) into neural impulses.

Just-noticeable difference (JND)

Minimum difference between two stimuli required for detection 50% of the time.

Sensory adaptation

Diminished sensitivity as a consequence of constant stimulation.

Weber’s law

Principle that two stimuli must differ by a constant minimum percentage to be different.

Sensory interaction

Principle that one sense may influence another (e.g., smell and taste).

Synesthesia

Condition where stimulation of one sense leads to experiences in a second sense.

Retina

The light-sensitive inner surface of the eye.

Blind spot

Point where the optic nerve leaves the eye; no receptor cells are located here.

Lens

Transparent structure that changes shape to help focus images on the retina.

Accommodation

The process by which the eye's lens changes shape to focus near or far objects.

Nearsightedness

Condition where nearby objects are seen clearly but distant objects are blurry.

Farsightedness

Condition where distant objects are seen clearly but nearby objects are blurry.

Rods

Photoreceptors that detect black, white, and gray; used for night vision.

Cones

Photoreceptors that detect fine detail and color; used in daylight.

Trichromatic theory

Theory that the retina contains three color receptors (red, green, blue).

Opponent-process theory

Theory that opposing retinal processes enable color vision.

Ganglion cells

Neurons that relay information from the retina to the brain via the optic nerve.

Afterimages

Sensations that remain after a stimulus is removed.