APPSYCH Unit #1 Section #1 First 30 terms

sensation

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

sensory receptors

sensory nerve endings that respond to stimuli

perception

the process by which our brain organizes and intercepts sensory information, enabling us to recognize things as meaningful.

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 from experiences or expectations

transduction

conversion of one form of energy into another. example: sensation— we transform physical energy to neural impulses

psychophysics

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

embodied cognition

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

absolute threshold

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

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, motivations and alertness

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

synesthesia

when the stimulation of one sense triggers the experience of another

Weber’s law

the principle that, to be perceived as different, 2 stimuli must differ by a constant minimum percentage. (rather than a constant amount)

sensory adaptation

diminished sensitivity as a consequence of constant stimulation

wavelength

the distance from the peak of one light wave or sound wave to the peak of the next. electromagnetic wavelengths vary from the short gamma rays to the long pulses of radio transmission.

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

cornea

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

pupil

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

iris

a ring of muscle tissue that forms the colored portion of the eye around the pupil and control the size of the pupil opening

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

accomodation

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

rods

retinal receptors that detect black, white, and gray, and are sensitive to movement, necessary for peripheral and twilight vision

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

blind spot

the point at which the optic nerve leaves the eye, creating a “blind spot” because no receptor cells are located there.

fovea

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

Young-Helmholtz trichromatic (three way) theory

the theory that the retina contains 3 different types of color receptors—red, blue, green—which, when stimulated in combination, can produce the perception of any color