Unit 3 - Sensation and Perception

Sensation

process of detecting physical energy and turning it into signals our brain can understand

Absolute threshold

smallest amount of a stimulus you can notice half the time

Transduction

turning energy like light waves into neural signals your brain can use

Just-noticeable difference

smallest change you can detect between two stimuli

Sensory adaptation

when you stop noticing a constant stimulus like your socks

Weber’s law

the bigger the stimulus the bigger the change needed to notice a difference

Sensory interaction

senses work together like taste and smell combining for flavor

Synesthesia

when senses mix up like seeing colors when hearing sounds

Retina

back of the eye that holds light sensitive cells

Blind spot

spot on the retina where there are no receptors

Lens & accommodation

lens bends to focus light and accommodation is when it changes shape

Nearsightedness

can see near not far because the eye is too long

Farsightedness

can see far not near because the eye is too short

Photoreceptors (rods & cones)

rods see dim light cones see color and detail

Wavelengths & colors

short waves look blue long waves look red

Trichromatic theory

three cones red green and blue make all colors

Opponent-process theory

color pairs red green and blue yellow explain afterimages

Ganglion cells

carry visual info from retina to brain

Afterimages

when you still see an image after looking away

Color vision deficiency

cone or ganglion cell issues cause color blindness

Prosopagnosia

face blindness or trouble recognizing faces

Blindsight

can respond to things seen without consciously seeing them

Wavelengths & amplitudes

wavelength is pitch or color amplitude is loudness or brightness

Place theory + volley theory

place theory says pitch comes from where hair cells fire volley theory says cells take turns for high sounds

Frequency theory

pitch is based on how fast hair cells fire

Sound localization

knowing where sound comes from using both ears

Conduction deafness

middle ear damage blocks sound waves

Sensorineural deafness

inner ear or nerve damage keeps brain from getting sound info

Sensation of hot

brain mixes warm and cold signals to feel heat

Phantom limb sensation

feeling pain or touch in a limb that is gone

Vestibular sense (semicircular canals)

sense of balance and movement in inner ear

Kinesthesis

sense of body position and movement

Olfaction

sense of smell

Not processed in brain

smell skips the thalamus and goes to emotion and memory centers

Pheromones

chemicals that affect others behavior

Gustation

sense of taste

Sweet sour salty bitter umami & oleogustus

the six main taste types oleogustus means fat

Taste receptors

taste bud cells that detect chemicals

Supertasters nontasters

supertasters have more taste buds nontasters have fewer

Bottom-up processing

start with details and build the full picture

Top-down processing

use experience and expectations to interpret info

Schemas & perceptual sets

mental templates that shape what you expect to see

Contexts experiences & culture

shape how you see and interpret the world

Closure

filling in gaps to see a complete image

Figure-ground

focus on one part as figure rest is background

Proximity

things close together seem grouped

Similarity

similar things look like they belong together

Selective attention

focusing on one thing and ignoring others

Cocktail party phenomenon

hearing your name in a noisy room even when not paying attention

Change blindness

missing changes in the environment because focus is elsewhere

Binocular cues

depth cues using both eyes

Retinal disparity

eyes see slightly different images to judge depth

Convergence

eyes move inward for close objects

Monocular cues

depth cues needing one eye

Relative clarity

clear means close hazy means far

Relative size

smaller means farther away

Texture gradient

more detail means closer smooth means far

Linear perspective

parallel lines appear to meet in distance

Interposition

one object blocking another means it is closer

Visual perception constancies

seeing objects as the same size shape or color even when they change visually

Apparent movement

still images look like motion like animation