AP pych review

axon

the segmented neuron extension that passes messages through its branches to other neurons or to muscles or glands.

endorphins [en-DOR-fins]

“morphine within”; natural, opioid-like neurotransmitters linked to pain control and to pleasure.

barbiturates

drugs that depress central nervous system activity, reducing anxiety but impairing memory and judgment.

levels of analysis

the differing complementary views, from biological to psychological to social-cultural, for analyzing any given phenomenon.

fMRI (functional MRI)

a technique for revealing blood flow and, therefore, brain activity by comparing successive MRI scans.

hindbrain

consists of the medulla, pons, and cerebellum; directs essential survival functions, such as breathing, sleeping, and wakefulness, as well as coordination and balance.

midbrain

found atop the brainstem; connects the hindbrain with the forebrain, controls some motor movement, and transmits auditory and visual information.

forebrain

consists of the cerebral cortex, thalamus, and hypothalamus; manages complex cognitive activities, sensory and associative functions, and voluntary motor activities.

brainstem

the central core of the brain, beginning where the spinal cord swells as it enters the skull; the brainstem is responsible for automatic survival functions.

medulla [muh-DUL-uh]

the hindbrain structure that is the brainstem’s base; controls heartbeat and breathing.

thalamus [THAL-uh-muss]

the forebrain’s sensory control center, located on top of the brainstem; it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla.

reticular formation

a nerve network that travels through the brainstem into the thalamus; it filters information and plays an important role in controlling arousal.

limbic system

neural system located mostly in the forebrain — below the cerebral hemispheres — that includes the amygdala, hypothalamus, hippocampus, thalamus, and pituitary gland; associated with emotions and drives.

frontal lobes

the portion of the cerebral cortex lying just behind the forehead. They enable linguistic processing, muscle movements, higher- order thinking, and executive functioning (such as making plans and judgments).

parietal [puh-RYE-uh-tuhl] lobes

the portion of the cerebral cortex lying at the top of the head and toward the rear; it receives sensory input for touch and body position.

occipital [ahk-SIP-uh-tuhl] lobes

the portion of the cerebral cortex lying at the back of the head; it includes areas that receive information from the visual fields.

temporal lobes

the portion of the cerebral cortex lying roughly above the ears; it includes the auditory areas, each of which receives information primarily from the opposite ear. They also enable language processing.

motor cortex

a cerebral cortex area at the rear of the frontal lobes that controls voluntary movements.

association areas

areas of the cerebral cortex that are not involved in primary motor or sensory functions, but rather are involved in higher mental functions such as learning, remembering, thinking, and speaking.

cognitive neuroscience

the interdisciplinary study of the brain activity linked with cognition (thinking, knowing, remembering, and communicating).

sleep

a periodic, natural loss of consciousness — as distinct from unconsciousness resulting from a coma, general anesthesia, or hibernation. (Adapted from Dement, 1999.)

circadian [ser-KAY-dee-an] rhythm

our biological clock; regular bodily rhythms (for example, of temperature and wakefulness) that occur on a 24-hour cycle.

hypnagogic sensations

bizarre experiences, such as jerking or a feeling of falling or floating weightlessly, while transitioning to sleep. (Also called hypnic sensations.)

suprachiasmatic nucleus (SCN)

a pair of cell clusters in the hypothalamus that controls circadian rhythm. In response to light, the SCN adjusts melatonin production, thus modifying our feelings of sleepiness.

narcolepsy

a sleep disorder characterized by uncontrollable sleep attacks. The affected person may lapse directly into REM sleep, often at inopportune times.

REM sleep behavior disorder

a sleep disorder in which normal REM paralysis does not occur; instead, twitching, talking, or even kicking or punching may occur, often acting out one’s dream.

sensation

the process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment.

bottom-up processing

information processing that begins with the sensory receptors and works up to the brain’s integration of sensory information.

top-down processing

information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experience and expectations.

signal detection theory

a theory predicting how and when we detect the presence of a faint stimulus (signal) amid background stimulation (noise); assumes there is no single absolute threshold and that detection depends partly on a person’s experience, expectations, motivation, and alertness.

difference threshold

the minimum difference between two stimuli required for detection 50 percent of the time. We experience the difference threshold as a just noticeable difference (jnd).

sensory adaptation

diminished sensitivity as a consequence of constant stimulation.

pupil

the adjustable opening in the center of the eye through which light enters.

accommodation

the process by which the eye’s lens changes shape to focus images of near or far objects on the retina.

feature detectors

nerve cells in the brain’s visual cortex that respond to specific features of the stimulus, such as shape, angle, or movement.

audition

the sense or act of hearing.

sensorineural hearing loss

the most common form of hearing loss, caused by damage to the cochlea’s receptor cells or to the auditory nerve; also called nerve deafness.

conduction hearing loss

a less common form of hearing loss, caused by damage to the mechanical system that conducts sound waves to the cochlea.

cochlear implant a device

for converting sounds into electrical signals and stimulating the auditory nerve through electrodes threaded into the cochlea.

place theory

in hearing, the theory that links the pitch we hear with the place where the cochlea’s membrane is stimulated. (Also called place coding.)

frequency theory

in hearing, the theory that the rate of nerve impulses traveling up the auditory nerve matches the frequency of a tone, thus enabling us to sense its pitch. (Also called temporal coding.)

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. The “gate” is opened by the activity of pain signals traveling up small nerve fibers, and is closed by activity in larger fibers or by information coming from the brain.

kinesthesis [kin-ehs-THEE- sis]

our movement sense; our system for sensing the position and movement of individual body parts.

vestibular sense

our balance sense; our sense of body movement and position that enables our sense of balance.

embodied cognition

the influence of bodily sensations, gestures, and other states on cognitive preferences and judgments.

natural selection

the principle that the inherited traits enabling an organism to survive and reproduce in a particular environment will (in competition with other trait variations) most likely be passed on to succeeding generations.

behavior genetics

the study of the relative power and limits of genetic and environmental influences on behavior.

heredity

the genetic transfer of characteristics from parents to offspring.

interaction

the interplay that occurs when the effect of one factor (such as environment) depends on another factor (such as heredity).

epigenetics

“above” or “in addition to” (epi) genetics; the study of the molecular mechanisms by which environments can influence genetic expression (without a DNA change).

peripheral nervous system (PNS)

the sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body.

nerves

bundled axons that form neural cables connecting the central nervous system with muscles, glands, and sensory organs.

neuron

a nerve cell; the basic building block of the nervous system.

cell body

the part of a neuron that contains the nucleus; the cell’s life-support center.

action potential

a neural impulse; a brief electrical charge that travels down an axon.

threshold

the level of stimulation required to trigger a neural impulse.

agonist

a molecule that increases a neurotransmitter’s action.

endocrine [EN-duh-krin]

system the body’s “slow” chemical communication system; a set of glands and fat tissue that secrete hormones into the bloodstream.

opioids

opium and its derivatives; they depress neural activity, temporarily lessening pain and anxiety.

biological psychology

the scientific study of the links between biological (genetic, neural, hormonal) and psychological processes. Some biological psychologists call themselves behavioral neuroscientists, neuropsychologists, behavior geneticists, physiological psychologists, or biopsychologists.

biopsychosocial approach

an integrated approach that incorporates biological, psychological, and social-cultural levels of analysis.

EEG (electroencephalogram)

an amplified recording of the waves of electrical activity sweeping across the brain’s surface. These waves are measured by electrodes placed on the scalp.

MEG (magnetoencephalography)

a brain-imaging technique that measures magnetic fields from the brain’s natural electrical activity.

CT (computed tomography) scan

a series of X-ray photographs taken from different angles and combined by computer into a composite representation of a slice of the brain’s structure.

cerebellum

the hindbrain’s “little brain” at the rear of the brainstem; its functions include processing sensory input, coordinating movement output and balance, and enabling nonverbal learning and memory.

amygdala [uh-MIG-duh-la]

two lima-bean–sized neural clusters in the limbic system; linked to emotion.

cerebral [seh-REE-bruhl] cortex

the intricate fabric of interconnected neural cells covering the forebrain’s cerebral hemispheres; the body’s ultimate control and information-processing center.

neurogenesis

the formation of new neurons.

corpus callosum [KOR-pus kah-LOW-sum]

the large band of neural fibers connecting the two brain hemispheres and carrying messages between them.

split brain

a condition resulting from surgery that separates the brain’s two hemispheres by cutting the fibers (mainly those of the corpus callosum) connecting them.

consciousness

our subjective awareness of ourselves and our environment.

dual processing

the principle that information is often simultaneously processed on separate conscious and unconscious tracks.

blindsight

a condition in which a person can respond to a visual stimulus without consciously experiencing it.

parallel processing

processing multiple aspects of a stimulus or problem simultaneously.

sequential processing

processing one aspect of a stimulus or problem at a time; generally used to process new information or to solve difficult problems.

hallucinations

false sensory experiences, such as seeing something in the absence of an external visual stimulus.

delta waves

the large, slow brain waves associated with deep sleep.

insomnia

recurring problems in falling or staying asleep.

sensory receptors

sensory nerve endings that respond to stimuli.

perception

the process by which our brain organizes and interprets sensory information, enabling us to recognize objects and events as meaningful.

psychophysics

the study of relationships between the physical characteristics of stimuli, such as their intensity, and our psychological experience of them.

absolute threshold

the minimum stimulus energy needed to detect a particular stimulus 50 percent of the time.

subliminal

below one’s absolute threshold for conscious awareness.

priming

the activation, often unconsciously, of certain associations, thus predisposing one’s perception, memory, or response.

Weber’s law

the principle that, to be perceived as different, two stimuli must differ by a constant minimum percentage (rather than a constant amount).

hue

the dimension of color that is determined by the wavelength of light; what we know as the color names blue, green, and so forth.

intensity

the amount of energy in a light wave or sound wave, which influences what we perceive as brightness or loudness. Intensity is determined by the wave’s amplitude (height).

cornea

the eye’s clear, protective outer layer, covering the pupil and iris.

lens

the transparent structure behind the pupil that changes shape to help focus images on the retina.

retina

the light-sensitive back inner surface of the eye, containing the receptor rods and cones plus layers of neurons that begin the processing of visual information.

rods

retinal receptors that detect black, white, and gray, and are sensitive to movement. Rods are necessary for peripheral and twilight vision, when cones don’t respond.

cones

retinal receptors that are concentrated near the center of the retina and that function in daylight or in well-lit conditions.

optic nerve

the nerve that carries neural impulses from the eye to the brain.

fovea

the central focal point in the retina, around which the eye’s cones cluster.

opponent-process theory

the theory that opposing retinal processes (red-green, blue-yellow, white-black) enable color vision. For example, some cells are stimulated by green and inhibited by red; others are stimulated by red and inhibited by green.

frequency

the number of complete wavelengths that pass a point in a given time (for example, per second).

middle ear

the chamber between the eardrum and the cochlea containing three tiny bones that concentrate the vibrations of the eardrum on the cochlea’s oval window.

inner ear

the innermost part of the ear, containing the cochlea, semicircular canals, and vestibular sacs.

gustation

our sense of taste.

olfaction

our sense of smell.