AP Psychology MIdterm

absolute threshold

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

accommodation

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

Acetylcholine

enables muscle action, learning, and memory

action potential

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

Adenosine

a neurotransmitter that causes drowsiness and the slowing of nerve cells. Caffeine is an antagonist that blocks the transmission of adenosine keeping us awake.

adreanal glands

set of endocrine glands that sit above kidneys, help with body arousal during stress

Adrenaline

A hormone released into the bloodstream in response to physical or mental stress

afferent neurons

neurons that take information from the senses to the brain

all-or-none response

a neuron's reaction of either firing (with a full-strength response) or not firing.

Alocohol

The most common drug which leads to more dilute urine, by acting as an ADH suppressant.

alpha waves

the relatively slow brain waves of a relaxed, awake state

amplitude

height of a wave; influences brightness in visual perception and volume in audition

Androgens

male sex hormones

audition

the sense of hearing

autonomic nervous system

The part of the PNS that controls the glands and the muscles of the internal organs.

Axon

the extension of a neuron, ending in branching terminal fibers, through which messages pass to other neurons or to muscles or glands

axon terminal

The endpoint of a neuron where neurotransmitters are stored

basilar membrane

area within the cochlea where hair cells are located

beta waves

awake and alert

binocular cues

depth cues that require the combined input of both eyes

bipolar cells

second layer of neurons in the retina that transmit impulses from rods and cones to ganglion cells; rods share these, but cones do not

blind spot

the point at which the optic nerve leaves the eye; no receptors cells are located there. Creates a gap in our vision that is "filled" by the brain.

bottom-up processing

analysis that begins with the sense receptors and works up to the brain's integration of sensory information.

Broca's aphasia

condition resulting from damage to Broca's area, causing the affected person to be unable to speak fluently, to mispronounce words, and to speak haltingly

Broca's area

controls language expression - an area, usually in the left frontal lobe, that directs the muscle movements involved in speech.

Caffeine

a mild stimulant found in coffee, tea, and several other plant-based substances

Calcitonin

Lowers blood calcium levels

Carl Wernicke

discovered a brain area responsible for interpreting meaning of language

central nervous system

made up of the brain and spinal cord

cerebral cortex

outer region of the cerebrum, containing sheets of nerve cells; gray matter of the brain

change blindness

when paying attention to a specific aspect of a visual scene, we may fail to notice other fairly obvious changes or presentations of stimuli; demonstrated by the door study and the gorilla illusion

Charles Darwin

English natural scientist who formulated a theory of evolution by natural selection (1809-1882)

Chromosomes

threadlike structures made of DNA molecules that contain the genes

circadian rhythm

the biological clock; regular bodily rhythms that occur on a 24-hour cycle

closure

Gestalt grouping principle; we fill in "gaps" to create a full, complete object

cochlea

snail-shaped tube in the inner ear that contains fluid that moves in response to vibrations, stimulating activity on the basilar membrane

cochlear implant

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

cocktail party effect

ability to selectively attend to one voice among many

color constancy

perceiving familiar objects as having consistent color, even if changing illumination alters the wavelengths reflected by the objects.

conduction hearing loss

hearing loss caused by damage to the (mechanical) middle ear structures that conduct sound waves to the cochlea.

cones

Receptor cells that are concentrated near the center of the retina and that function in daylight or in well-lit conditions. They detect fine details and give rise to color sensation.

connectedness

Gestalt grouping principle; when objects uniform (in color or texture) are linked (no space exists between them) we perceive them as a single unit

continuity

Gestalt grouping principle; our tendency to perceive smooth, continuous patterns rather than discontinuous ones

convergence

a binocular cue for perceiving depth; the more the eyes strain to turn inwards to view an object, the closer the object is (note: only a factor at close ranges)

corpus callosum

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

Cortisol

stress hormone released by the adrenal cortex

CT scan

a series of x-ray photographs taken from different angles and combined by computer into a composite representation of a slice through the body

David Hubel & Torsten Wiesel

Nobel-prize-winning researchers who discovered "feature detectors" within the brain

Dendrite

the bushy, branching extensions of a neuron that receive messages and conduct impulses toward the cell body

Depolarization

The process during the action potential when sodium is rushing into the cell causing the interior to become more positive.

Depressants

drugs (such as alcohol, barbiturates, and opiates) that reduce neural activity and slow body functions

depth perception

the ability to see objects in three dimensions although the images that strike the retina are two-dimensional; allows us to judge distance

difference threshold

the minimum difference between two stimuli required for detection 50% of the time; also referred to as just noticeable difference (JND)

DNA

A complex molecule containing the genetic information that makes up the chromosomes.

dominant allele

An allele whose trait always shows up in the organism when the allele is present.

Dopamine

a neurotransmitter that regulates motor behavior, motivation, pleasure, and emotional arousal

EEG (electroencephalogram)

shows brain's electrical activity by positioning electrodes over the scalp

efferent neurons

Nerve cells that conduct impulses away from the central nervous system

embodied cognition

in psychological science, the influence of bodily sensations, gestures, and other states on cognitive preferences and judgments

endocrine system

the body's "slow" chemical communication system; a set of glands that secrete hormones into the bloodstream

Endorphins

natural, opiate-like neurotransmitters linked to pain control and to pleasure

Epigenetics

the study of environmental influences on gene expression that occur without a DNA change

Epinephrine

Neurotransmitter secreted by the adrenal medulla in response to stress. Also known as adrenaline.

Ernst Weber

early psychologist who established that the proportion of difference (rather than absolute difference) between two stimuli that is required for distinguishing between them is constant for particular types of sensation (e.g. weight, brightness, etc).

Estrogren

influences the development of female secondary sex characteristics

excitory neurotransmitters

cause next neuron to fire

extrasensory perception (ESP)

the controversial claim that perception can occur apart from sensory input; includes telepathy, clairvoyance, and precognition

feature detectors

nerve cells in the brain that respond to specific features of the stimuli, such as shape, angle, or movement.

figure-ground

A gestalt perceptual phenomenon; the organization of the visual field into objects that stand out from their surroundings

fMRI

a form of magnetic resonance imaging of the brain that registers blood flow to functioning areas of the brain

fovea

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

frequency

the number of complete wavelengths that pass a point in a given time; determines perception of hue in light and of pitch in sound

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.

frontal lobes function

control skilled voluntary movements of limbs and trunk

coordinate muscles involved in speech

control voluntary movements of eyes and eyelids

concentration, problem-solving, and planning

GABA (gamma-aminobutyric acid)

A major inhibitory neurotransmitter. Undersupply linked to seizures, tremors, and insomnia.

gate-control theory

the theory that the spinal cord contains neurological "gate" that blocks pain signals or allows them to pass on to the brain. The "gate" is open by the activity of pain signals traveling up small nerve fibers and is closed by activity in larger fibers or by information coming form the brain.

Gene

A segment of DNA on a chromosome that codes for a specific trait

Genotype

An organism's genetic makeup, or allele combinations.

gestalt

a perceptual whole; derived from German word meaning "form" or "whole"

Glutamate

The most common neurotransmitter in the brain. Excitatory.

Gonads

sex glands

grouping

the perceptual tendency to organize stimuli into coherent groups

gustation

sense of taste

Gustav Fechner

often credited with founding "psychophysics" as a subfield of psychology; studied afterimages

hair cells

finger-like projections on the basilar membrane that stimulate activity of the auditory nerve

Hallucinogens

psychedelic drugs, such as LSD, that distort perceptions and evoke sensory images in the absence of sensory input

Heroin

narcotic drug derived from opium that is extremely addictive

Heterozygous

An organism that has two different alleles for a trait

Homozygous

An organism that has two identical alleles for a trait

hue

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

inhibitory neurotransmitters

chemicals released from the terminal buttons of a neuron that inhibit the next neuron from firing

inner ear

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

insomnia

inability to sleep

interposition

monocular cue for depth perception; if one object partially blocks our view of another object, we perceive it as closer

iris

a ring of muscle tissue that forms the color portions of the eye around the pupil and controls the size of the pupil opening.

kinesthesia

the system for sensing the position and movement of individual body parts; enabled by feedback from proprioceptors (which provide info about the movement of muscles, tendons, joints); also called "proprioception"

latent content

the underlying meaning of a dream