AP Psychology Exam Study Guide: Biological Bases, Cognition, Sensation, and Research Methods

Comprehensive vocabulary flashcards covering the nervous system, brain structures, neuroimaging methods, consciousness, sensation, audition, vision, and research methods based on the provided AP Psychology Unit 1 exam study sheets.

All-or-None Firing

The principle that a neuron either fires completely with a full-strength action potential once threshold is reached or does not fire at all.

Activation-Synthesis Theory

A biological dream theory proposing that dreams are the brain's attempt to synthesize and make sense of random neural activity originating from the brainstem during REM sleep.

Information-Processing Theory

A dream theory proposing that dreaming serves to sift, sort, consolidate, and fix the day's experiences into long-term memory.

Sleep Apnea

A sleep disorder characterized by temporary cessations of breathing during sleep and repeated momentary awakenings.

Narcolepsy

A sleep disorder marked by uncontrollable sleep attacks, where the sufferer may lapse directly into REM sleep at inopportune times.

REM Sleep Behavior Disorder

A sleep condition where normal muscle paralysis (atonia) during REM sleep is absent, leading individuals to physically act out their dreams.

Night Terrors

A sleep disorder occurring during NREM-3 (deep) sleep featuring high arousal and an appearance of being terrified, unlike nightmares which occur during REM sleep.

Medulla

The base of the brainstem that controls vital, autonomic life-support functions such as heartbeat and breathing.

Pons

A brainstem structure located above the medulla that plays a key role in regulating sleep, dreaming, and relaying sensory information between the cerebellum and cortex.

Reticular Activating System (RAS)

A network of neurons in the brainstem that controls alertness, wakefulness, arousal, and filters incoming sensory stimuli.

Cerebellum

The hindbrain structure responsible for coordinating voluntary movements, balance, and processing implicit procedural memories.

Thalamus

The brain's sensory relay center located atop the brainstem; it directs incoming sensory signals (except smell) to the appropriate areas of the cerebral cortex.

Hypothalamus

A limbic system structure below the thalamus that regulates the autonomic nervous system, endocrine system via the pituitary gland, and drives like hunger, thirst, and body temperature.

Hippocampus

A limbic system structure vital for processing and consolidating explicit, conscious memories for long-term storage.

Amygdala

Two lima-bean-sized neural clusters in the limbic system linked to emotional processing, particularly fear and aggression.

Corpus Callosum

The large band of neural fibers connecting the left and right cerebral hemispheres, enabling communication between them.

Frontal Lobes

Cortical regions behind the forehead involved in speaking, muscle movements (motor cortex), planning, decision-making, and judgment.

Parietal Lobes

Cortical regions at the top rear of the head containing the somatosensory cortex, which processes bodily touch, temperature, and spatial awareness.

Occipital Lobes

Cortical regions at the back of the head that include the visual cortex for receiving and processing visual information.

Temporal Lobes

Cortical regions situated above the ears that include the auditory cortex for hearing and language processing.

Motor Cortex vs. Somatosensory Cortex

The motor cortex (in the frontal lobe) controls voluntary muscle movements, whereas the somatosensory cortex (in the parietal lobe) registers and processes body touch and movement sensations.

Broca's Area vs. Broca's Aphasia

Broca's area is the left frontal lobe region directing speech muscle movements; damage causes Broca's aphasia, characterized by difficulty producing fluent speech while comprehension remains intact.

Wernicke's Area vs. Wernicke's Aphasia

Wernicke's area is the left temporal lobe region involved in language comprehension; damage causes Wernicke's aphasia, leading to fluent but meaningless speech and severe comprehension deficits.

Split-Brain Research

Studies pioneered by Sperry and Gazzaniga on patients whose corpus callosum was severed, revealing hemisphere specialization (e.g., left hemisphere language production vs. right hemisphere spatial tasks).

Brain Plasticity

The brain's ability to modify, reorganize, and build new neural pathways in response to experience, learning, or following damage.

Deep Brain Stimulation (DBS)

A neurosurgical procedure involving the implantation of electrodes within specific brain regions to deliver electrical impulses and treat movement or affective disorders.

Transcranial Magnetic Stimulation (TMS)

A noninvasive technique applying magnetic pulses across the scalp to stimulate or temporarily disrupt electrical activity in specific cortical regions.

Electroencephalogram (EEG)

An amplified recording of electrical brain wave activity measured by electrodes placed on the scalp.

Positron Emission Tomography (PET Scan)

A functional neuroimaging technique that detects metabolic activity and glucose consumption across brain areas using a radioactive tracer.

Functional MRI (fMRI)

An imaging technique comparing successive MRI scans to reveal brain activity by tracking blood flow and oxygen consumption in real time.

Synesthesia

A neurological phenomenon in which stimulation of one sensory or cognitive pathway leads to involuntary, automatic experiences in a second, unrelated pathway (e.g., hearing colors).

Photoreceptors: Rods vs. Cones

Rods detect black, white, and gray, function well in peripheral and dim light; cones detect fine detail and color, are concentrated in the fovea, and function in well-lit conditions.

Trichromatic Theory (Young-Helmholtz)

The theory that the retina contains three distinct types of color receptor cones, each maximally sensitive to red, green, or blue wavelengths.

Opponent-Process Theory

The theory that opposing retinal and thalamic processes (red-green, blue-yellow, white-black) enable color vision and account for afterimages.

Fovea

The central focal point in the retina around which the eye's cones cluster, providing the sharpest visual acuity.

Blind Spot

The area on the retina where the optic nerve leaves the eye, creating a gap in the visual field because no photoreceptors are present.

Place Theory vs. Frequency Theory

Place theory links pitch to the specific location on the basilar membrane that is stimulated (best for high frequencies); frequency theory links pitch to the firing rate of the auditory nerve matching the frequency of the sound wave (best for low frequencies).

Volley Theory (Volley Principle)

An auditory principle stating that neural cells alternate rapid firing in succession to achieve combined frequencies exceeding the maximum single-cell firing rate of $1000\,\text{pulses/s}$.

Olfaction (Smell)

The chemical sense of smelling airborne molecules; unique among major senses because its sensory signals travel directly to the olfactory bulb and cortex, bypassing the thalamus entirely.

Gate-Control Theory

The theory that the spinal cord contains a neurological gate that blocks pain signals or allows them to pass on to the brain depending on activity in small pain fibers versus large non-pain fibers.

Vestibular Sense vs. Kinesthesis

Vestibular sense monitors head position, movement, and overall body balance via the fluid-filled semicircular canals in the inner ear; kinesthesis monitors the position and movement of individual body parts via receptors in joints, tendons, and muscles.

Standard Deviation

A computed measure of variation indicating the average distance and spread of individual data scores around the mean.

Correlation Coefficient ($r$-score)

A statistical index ranging from $-1.0$ to $+1.0$ that measures the strength and direction of the linear relationship between two variables.

$p$-value

A statistical measure indicating the probability that experimental results occurred by random chance; a value of $p < 0.05$ is typically required for statistical significance.

Operational Definition

A carefully worded statement of the exact procedures and measurements used in a research study to define variables, ensuring replicability.

Random Assignment vs. Random Selection

Random selection ensures every member of a population has an equal chance of being chosen for a sample (improving generalizability); random assignment ensures participants have an equal chance of being placed into experimental or control groups (controlling confounding variables).

Double-Blind Study

An experimental procedure where neither the research participants nor the researchers collecting data know who received the treatment versus the placebo, eliminating experimenter and participant bias.

Sympathetic vs. Parasympathetic Nervous System

The sympathetic division mobilizes body resources for 'fight-or-flight' (accelerating heart rate, inhibiting digestion); the parasympathetic division calms the body for 'rest-and-digest' (slowing heart rate, stimulating digestion).

Sensory (Afferent) vs. Motor (Efferent) Neurons

Sensory (afferent) neurons carry incoming information from sensory receptors inward to the brain and spinal cord; motor (efferent) neurons carry outgoing instructions from the brain and spinal cord outward to muscles and glands.

Action Potential

A brief electrical charge that travels down an axon, initiated by an influx of sodium ions ($\text{Na}^+$) depolarizing the neural membrane.

Reuptake vs. Enzymatic Degradation

The two primary methods of clearing neurotransmitters from the synaptic cleft: reuptake involves reabsorption by the presynaptic neuron, while enzymatic degradation involves chemical breakdown by specific enzymes.

Agonist vs. Antagonist

An agonist is a molecule that binds to a receptor and mimics or increases a neurotransmitter's action; an antagonist binds to a receptor and blocks or inhibits the neurotransmitter's action.

Circadian Rhythm

The internal biological clock that regulates bodily rhythms (including body temperature and wakefulness) on an approximate 24-hour cycle.

Brain Waves (Beta, Alpha, Theta, Delta)

Electroencephalogram patterns reflecting states of consciousness: Beta waves occur during alert waking states; Alpha during relaxed wakefulness; Theta during light NREM-1 sleep; and Delta during deep NREM-3 slow-wave sleep.

Transduction

The conversion of one form of physical sensory energy (such as light, sound waves, or odor molecules) into neural impulses that the brain can interpret.

Absolute Threshold

The minimum stimulus energy needed to detect a specific stimulus (such as light, sound, or odor) at least $50\%$ of the time.

Just Noticeable Difference (Weber's Law)

The minimum difference between two stimuli required for detection $50\%$ of the time; Weber's Law states that to be perceived as different, stimuli must differ by a constant minimum percentage rather than a constant amount.

Sensory Adaptation vs. Habituation

Sensory adaptation is diminished sensitivity at the sensory receptor level due to constant, unchanging stimulation; habituation is a decrease in behavioral response at the central cognitive level after repeated exposure to a familiar stimulus.

Heroin

depressant drug, agonist of dopamine (excitatory). Narcotic drug derived from opim that is extremely addictive.

Ecstasy (MDMA)

Designer drug that can have both stimulant and hallucinatory effects. Produces increased energy, a distorted sense of time, and heightened sensory perception. Involved with neurotransmitter serotonin.

Marijuana

Hallucinogen drug, agonist of dopamine (excitatory). Mild hallucinogen derived from the leaves and flowers of a particular type of hemp plant.

LSD

Powerful synthetic hallucinogen, involved in the neurotransmitter serotonin. LSD mimics serotonin and sometimes is inhibitory and sometimes excitatory.

Meth

Stimulant drug, agonist involved with dopamine (excitatory).

Alcohol

Depressant drug, involved with neurotransmitters GABA and Glutamate. Inhibitory.

Cocaine

Stimulant drug, involved with dopamine by blocking transporters and dopamine overstimulates cell. Natural drug derived from the leaves of the coca plant.

Acetylcholine’s function

excitatory or inhibitory; involved in arousal, attention, memory, and controls muscle contractions.

Dopamine’s function

excitatory or inhibitory; involved in control of movement and sensations of pleasure.

serotonin function

excitatory or inhibitory; involved in sleep, mood, anxiety, and appetite.

Norepinephrine function

mainly excitatory; involved in arousal and mood.

GABA function

major inhibitory neurotransmitter; involved in sleep and inhibits movement

Glutamate function

major excitatory neurotransmitter; involved in learning, memory formation, nervous system development, and synaptic plasticity.

Endorphins function

can reduce the body’s stress response, help relieve pain, reduce stress and improve mood. Released when your body feels pain or stress.

Substance P

involved in regulating emotion and social behavior, involved in pain signaling, and modulates nerve activity.

withdrawal symptoms

nausea, pain, tremors, crankiness, high blood pressure, etc.

interneurons

neurons that connect the afferent neurons to the efferent neurons

cross sectional design

several different participant age-groups are studied at one particular point in time.

cross-sequential design

participants are first studied by means of a cross-sectional design but are also followed and assessed longitudinally.

presynaptic neuron

The transmitting neuron that releases neurotransmitters from its axon terminals across the synaptic cleft toward a receiving cell.

postsynaptic neuron

the neuron receiving the signal/message from the synapse

subliminal threshold

the boundary below which a sensory stimulus is too weak, fast, or quiet for a person to consciously detect it

CT scan

brain imaging method using computer-controlled X-rays of the brain in “slices”

cortex

outermost covering of the brain, consisting of densely packed nerves responsible for higher thought processes and interpretation of sensory input.

cerebrum

the upper part of the brain consisting of the two hemispheres and the structures that connect them.

mirror neurons

neurons that fire when an animal or person performs an action and also when an animal or person observes that same action being performed by another.

association areas

areas within each lobe of the cortex responsible for the coordination and interpretation of information, as well as higher mental processing.

retina

a light sensitive area at the back of the eye containing 3 layers (ganglion cells, bipolar cells, and rods and cones).

what are the 5 basic tastes

sweet, sour, salty, bitter, and umami.

semicircular canals

3 somewhat circular tubes filled with fluid that stimulate receptors when rotated.

what are the types of pain

visceral pain: pain in the internal organs

somatic pain: pain in the skin, joints, tendons, and muscles.

positive vs. negative skew

positive skew: the mean moves to the right of the area of central tendency

negative skew: the mean moves to the left of the arra of central tendency

opioids

synthetic drugs that mimic the pain-reducing effects of opiates and their addictive properties