AP Psychology - Biological Bases of Behavior: Test 3

sensation

the process by which a stimulated receptor (eyes, ears) creates a pattern of neural messages that represent the stimulus in the brain

perception

a mental process that elaborates and assigns meaning to incoming sensory patterns

bottom up processing

analysis that begins with sense receptors then goes to the brain and mind

top down processing

guided by higher level processing as we construct perceptions

perceptual set

mental predisposition to perceive one thing and not another because of top down processing

cocktail party effect

we are able to block out other stimuli to focus on one thing

inattentional blindness

we don’t notice something right infront of us because we aren’t paying attention

change blindness

failure to notice sudden changes (merging lanes into cyclists)

psychophysics

relationship between physical stimuli and our psychological experiences

absolute threshold

minimum amount of stimulation needed to detect something (candle flame seen from 30ft on a clear night)

subliminal threshold

when stimuli are below ones absolute threshold for conscious awareness

difference thresholds

the smallest amount of detectable change

weber’s law

to perceive as different, two stimuli must differ by a constant minimum percentage

signal detection theory (SDT)

predicts how and when we detect the presence of a faint stimulus, assumes there is no single absolute threshold

sensory adaptation

diminished physical sensitivity as a consequence of a constant (going into cold pool)

habituation

focuses on the cognitive/perceptual level

transduction

the sensory process that converts light/sound waves into a neural message

hue

dimension of color determined by wavelength

intensity

amount of energy in a wave determined by amplitude

cornea

outer covering of eye

pupil

adjustable center of eye where light enters

iris

dilates and constricts to change light intensity

lens

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

accommodation

lens focusing on retina

nearsightedness

near objects are clearer

farsightedness

far objects are clearer

acuity

sharpness of vision

retina

light sensitive inner surface, contains rods and cones and layers of neurons that begin visual processing

blind spot

the point at which the optic nerve leaves the eye, no receptor cells

fovea

central focus point in the retina

ganglion cells

neurons that connect to the bipolar cells, axons create the optic nerve

bipolar cells

neurons that connect rods and cones to the ganglion cells

optic chiasm

where optic nerves from each eye cross into opposite sides of the brain

visual pathway

axon of ganglion cells form optic nerve, half go to opposite hemisphere, while the rest go to the LGN

feature detectors

nerve cells that respond to specific features

parallel processing

motion, form, depth, color

trichromatic theory

retina receptors are sensitive to blue red and green

opponent process theory

hering, we process colors in pairs, red-green blue-yellow black-white

gestalt theory

argues that the brain forms a perceptual whole that is more than the sum of its sensory parts

grouping

we tend to group things based on proximity, continuity, and closure

law of pragnanz

we see the simplest organization, requires the least cognitive effort

binocular depth cues

uses both eyes

retinal disparity

images differ from each eye

convergence

moving eyes inward to see near objects

relative size

closer objects are larger

interposition

something infront is closer

linear perspective

lines converge in distance

relative motion/object parallax

closer objects seem to move faster

texture gradient

we see more texture closer

motion perception

changing size of objects

stroboscopic movement

animated movement

phi phenomenon

illusion of movement, flashing lighted signs

perceptual constancy

we see objects as stable even seeing it from different views (we don’t think someone shrank when they don’t)

moon illusion

when the moon is close to the horizon, it looks larger

ponzo illusions

size illusions, far away looks larger

critical period

you need visual stimulation by a certain age, or else it will negatively impact vision

perceptual adaptation

how we adapt to perceptual changes (upside down glasses)

frequency

the number of cycles completed by a wave in a given amount of time

amplitude

physical strength of a wave, volume

eardrum

vibrates sound

hammer, anvil, stirrup

bones in the ear that vibrate cochlea

cochlea

has fluid that vibrates to basilar membrane to auditory nerve which sends signal to thalamus then temporal lobe

place theory

the pitch we hear affects where the cochlea is vibrated

frequency theory

brain identifies pitch of sounds according to how rapidly nerve impulses fire

valley principle

neural cells alternate firing in rapid succession