Unit 6: Sensation and Perception

top-down processing

top-down processing

constructs perceptions from sensory input by drawing on own experiences (ex. expectation to see sheep not naked people, rat vs. old man, figuring out an abstract painting, etc.)

bottom-up processing

starts at sensory receptors and works up to higher levels of processing (ex. seeing naked men instead of sheep, guessing song in reverse, etc.)

selective attention

focus conscious awareness on one stimulus and ignoring other stimuli (ex. texting and driving)

cocktail party effect

ability to attend to one voice among other voices (ex. hear name being called somewhere else in a crowded room)

inattentional blindness

failing to see visible objects when our attention is directed elsewhere (ex. gorilla in brain scan)

change blindness

failing to notice changes in the environment (ex. magic color-changing card trick)

transduction

convert sensory info into electrical impulses that brain can understand

absolute threshold

minimum stimulation needed to detect a stimulus 50% of the time

subliminal

below one’s absolute threshold for conscious awareness (ex. arrow in FedEx logo)

difference threshold

smallest recognizable physical difference between two stimuli (ex. can you tell difference between Starbucks and expensive coffee? what about twins?)

priming

activate unconscious associations when we are affected by subliminal sensations (ex. Olivia Rodrigo seemingly copying Paramore)

sensory adaptation

diminished sensitivity as a consequence of constant stimulation (ex. getting used to cold pool water or a strong odor)

accommodation

lens changes curvature and thickness to focus on image

rods

sense receptors sensitive to dim light located in peripheral of fovea

cones

sense receptors sensitive to colors and concentrated in center of retina

Trichromatic Theory

retina has three cones (red, blue, green) that can be combined to form any visible color (criticism: Why can some colorblind people see yellow but not red or green, which make yellow?)

Opponent-Process Theory

bipolar cells process colors in complementary pairs (blue and yellow, red and green, black and white); looking at one color for a long period causes those receptor cells to become fatigued so their opposing cells fire, sending signals that cause the perception of the opposing color

feature detectors

nerve cells in brain’s visual cortex that respond to specific features of the stimulus, such as shape, angle, or movement (ex. allows driver to anticipate pedestrian’s next move)

parallel processing

processing many aspects of a problem simultaneously (ex. to analyze a visual scene, brain integrate separate subdimensions like motion, form, depth, and color)

Gestalt

organized whole: we have the tendency to integrate pieces of information into meaningful wholes

figure-ground

organization of visual field into figures that stand out from ground (ex. when you read, words are figures and white background is ground)

binocular cue

depth cue that depends on use of two eyes (ex. the reason you see finger sausage)

retinal disparity

binocular cue where the difference in the two retinal images (due to the angle from which each eye views an object) helps perceive depth

monocular cue

depth cue available to each separate eye (relative height, relative size, relative motion, interposition, linear perspective, light and shadow)

perceptual constancy

perceiving objects as unchanging even as illumination and retinal images change (ex. closed door vs open door are both the object)

frequency

longer wavelengths = lower ____

pitch

determined by frequency (ex. low frequency = long waves = low pitch)

middle ear

hammer, anvil, stirrup are three bones that pass along vibrations

inner ear

semicircular canals and cochlea

place theory

we hear different pitches because sound waves activate different places of the basilar membrane

frequency theory

we hear different pitches because nerve impulses match frequency of a sound wave

kinesthetic sense

the sense that provides information about body movement and position

vestibular sense

sense of balance

Chris Pratt Loves Ramen Outside By The Ocean

Light enters CORNEA, passes through PUPIL, LENS does accommodation, RETINA does transduction, bipolar cells send info to Ganglion cells. Info then exits OPTIC NERVE at BLINDSPOT, passes through THALAMUS, and then to OCCIPITAL LOBE

semicircular canals

help maintain balance and detects head motion

cochlea

creates impulse and contains cilia hairs that capture sound signals that are carried to brain

sensation

reception of info from sensory receptors

perception

process of organizing and interpreting sensory info

pinna

collects sound waves and channels them into the ear canal

eardrum

a tight membrane, and when sound waves hit it, it vibrates and sends those vibrations to the middle ear

afterimage

sensory experience that occurs after a visual experience has been removed; when eyes adjust to stimulation (or lack of) but they do not completely adjust/adapt (evidence of the opponent-process theory)