AP Psych Unit 2.3 Vocab

absolute threshold

The lowest amount of stimulation needed to detect a particular stimulus 50 percent of the time.

accommodation (vision)

The process in which the lens of the eye changes shape in response to external conditions so that an object remains in focus.

adaptation

The process by which the eye adjusts to varying levels of light or colors.

amplitude (loudness)

The height of the sound waves generated by an auditory stimulus.

binocular cue

A visual depth cue that requires the use of both eyes.

blind spot

An area or direction in which a person's vision is obscured because no receptor cells are located there.

cochlea

The snail-shaped, fluid-filled organ in the inner ear that contains the basilar membrane.

conduction deafness

Hearing loss related to problems with the ossicles, the bones of the middle ear.

cones

The visual receptors in the retina that are responsible for color vision, but are less useful for seeing in low-light conditions.

confabulation

An imagined but plausible memory that fills in gaps about what a person actually remembers.

convergence

A binocular cue that perceives depth; the eyes converge inward when looking at an object.

cornea

The clear part of the eye that lies in front of the iris and is part of the eye's protective covering.

depth perception

The ability to visually perceive the world and to understand spatial relationships in order to gauge the distances between objects.

eardrum

Another term for the tympanic membrane.

feature detection cells

Cells in the visual cortex of the brain that respond to different characteristics, or features, of a visual stimulus.

feature detection theory

An explanation for pattern recognition; the theory that we process images in terms of their constituent parts and then match the features of a pattern to those features stored in memory.

figure and ground

An aspect of perception where the perceived is separated into at least two parts, each with different attributes, but influencing one another.

fovea

A depression near the center of the retina that is densely packed with cones. The fovea is where vision is most acute.

frequency theory

A theory that sound is heard when pulses travel up the auditory nerve and carry the information to the brain for processing, and that the rate of this pulse exactly matches the frequency of whatever tone is heard.

gate control theory

The theory of pain perception that suggests there is a spinal "gate" that can be closed by signals from the brain. Closing the gate keeps pain signals from reaching the brain.

gustation

The sense of taste.

induced motion

An optical illusion in which a stationary object appears to move in one direction because of the movement of objects on either side of it in the opposite direction.

iris

The colored portion of the eye that controls how much light enters the pupil.

kinesthetic

The sense of body position. Also known as proprioception.

law of effect

Proposed by Edward Thorndike, the law of effect states that a behavior is likely to be repeated when it maximizes pleasure and/or minimizes pain.

lens

The portion of the eye that changes shape in order to focus the visual image onto the retina.

light adaptation

The changes that occur in the eye to permit vision when moving from darkness to light.

monocular cue

A visual depth cue that makes use of only one eye.

olfaction

The sense of smell.

opponent process theory

The theory that opposing retinal processes (red-green, black-white, yellow-blue) make color vision possible.

optic nerve

The cranial nerve that carries the visual impulse out of the back of the eye and into the brain for further processing.

parallel processing

A feature of the visual system in which many different processes are taking place simultaneously.

perception

The process of organizing and interpreting sensory information.

photoreceptors

The sense receptors for the visual system.

pitch (frequency)

The frequency of sound waves, which translates into the highness or lowness of a sound.

proximity

A Gestalt principle of perception that states that all else being equal, things that are near one another tend to be perceived as a unit.

pupil

The opening in the center of the eye that controls how much light is let into the eye.

retina

The layer of cells at the back of the eye where transduction of light waves into nerve signals takes place. It contains photoreceptors and additional neurons.

rods

Photoreceptors that respond to low levels of light.

semicircular canals

The three fluid-filled channels in the inner ear that are responsible for the vestibular sense, or sense of balance. The semicircular canals respond to changes in the position of the head and the rate of movement.

sensation

The raw, unelaborated awareness of stimulation.

sensory integration

A process of synthesizing information from two or more sensory systems.

subliminal

Sensory stimulation that is below the threshold of perception, but may still influence us in some way.

tastebuds

Sense organs that contain the chemical receptors for taste.

threshold

The minimum sensory stimulation required for detection.

timbre (complexity)

The quality of sound that is the result of the mixture of wavelengths in the sound.

transduction

The conversion of sensory stimuli, such as sound waves, into a form that can be processed by the sense receptors.

trichromatic (Young-Helmholtz) theory

A theory of color vision in which three types of color receptors produce the three basic colors of red, green, and blue.

vestibular sense

The sense of balance.

visible spectrum

The part or range of wavelengths of electromagnetic radiation that is visible to the human eye.

Weber's law

The rule that the just noticeable difference (JND) of a stimulus is proportional to the magnitude of the original stimulus. For example, a dim light doesn't need to brighten very much for us to notice it, but an already bright light must become much brighter for us to perceive the difference.