umit 4 sensation and perception

Sensation

the bottom-up process, which our senses, like vision, hearing, and smell, receive and relay outside stimuli

Perception

the top-down way our brains organize and interpret sensory information and put it into context

Bottom up processing

Sensory info received & travels to the brain ( perception)

Top bottom processing

Info processing guided by higher mental processing (sensation)

an example of the difference between sensation and perception

the physical detection of a smell and recognizing that smell is your grandmothers holiday bread

Absolute threshold

minimal strength to detect a stimulus 50% of the time

example of absolute threshold

the lightest touch on your skin that you feel

Signal detection theory

predicting how/when we detect weak stimuli

signal detection theory example

detecting signals under uncertainty (hearing your phone in a noisy room, maybe you hear it, maybe it’s in your head)

Subliminal

below the threshold of conscious awareness

sensory adaptation 

the decreased sensitivity to a constant stimulus over time

example of sensory adaptation

moving from bright sunlight into a dark room; your eyes gradually adjust 

what sense does not adapt

pain

selective attention 

your ability to focus on one or more sensory inputs and ignore all the others going on simultaneously 

selective attention examples

concentrating on a conversation in a noisy room or focusing on a single instrument in an orchestra

cocktail party effect

ability to focus on one voice in a noisy environment, like hearing your name across a crowded room 

inattentional blindness

failing to notice something visible because attention is focused elsewhere ( missing a gorilla walking through a basketball game) 

change blindness

failure to notice changes in a visual scene ( a person’s shirt color changing between cuts in a video)

wavelength ( vision)

determines color - shorter wavelength = blue/violet, longer = red 

amplitude ( hearing)

determines loudness- higher amplitude = louder sound 

intensity

refers to the strength of a stimulus ( brightness or volume) 

eye; cornea

protects the eye and bends light to focus

eye; pupil

small/ adjustable opening that lets light in

eye; iris

colored muscle that controls pupil size, adjust light intake 

eye; lens

focuses light onto retina, transparent structure behind pupil that change shape to focus images on the retina 

eye; retina

the light inner surface of eye, contains photoreceptors ( rods and cones) 

retina eye; rods

detect black, white and dim light

retina eye;cones

detect color and detail

eye; optic nerve

sends visual info to the brain , connects eye to brain 

eye; blind spot

area with no receptors where optic nerve exits, optic nerve leaves eye

eye; fovea

central focus point with high cone concentration

parallel processing

brain processes multiple aspects of a scene ( color, motion, depth) simultaneously

afterimages

visual illusion where an image remains after stimulus is removed ( seeing green after staring at red) 

color constancy

perceiving consistent color despite lighting changes ( a red apple looks red in sunlight and shade) 

size constancy

perceiving an object as the same size even when its distance changes 

shape constancy

recognizing an object’s shape despite changes in angle or perspective 

hearing; amplitude

loudness

hearing;frequency

pitch; higher frequency = higher pitch

hearing; sound measurement

measured in decibels (dB)

outer ear

pinna and auditory canal; collects sound

middle ear

3 bones; hammer,anvil,stirrup-amplify vibrations

inner ear

cochlea- fluid-filled, converts sound to neural signals

McGurk effect

visual input alters auditory perception ( seeing “ga” while hearing “ba” makes you perceive) 

cochlear implant

device that bypasses damaged parts of the ear to stimulate auditory nerve directly ( enable the brain to “hear” sounds)

4 skin senses

pressure,warmth,cold,pain

kinesthesia

sense of body part movement and position

vestibular sense

balance and spatial orientation (monitors the head and body’s position according to gravity)

sensory interaction 

one sense influences another ( ex. smell affects how something taste) 

figure ground

the idea that your brain separates what you’re focusing on from everything else in the background

proximity

objects that are close together

continuity

on going images/ things that are forever connected 

closure

filling in gaps to create whole objects

visual cliff

experiment showing depth perception in infants

binocular depth cues 

depth cues such retinal disparity that depend on the use of both eyes

retinal disparity

each eye sees slightly different image

monocular cues

uses one eye to judge depth

relative height

higher = farther

relative size

smaller = farther

interposition

overlapping = closer

relative motion

closer objects move faster

linear perspective

parallel lines converge with distance

light & shadow

shading implies depth

phi phenomenon

illusion of movement from blinking lights

perceptual constancy

perceiving objects as unchanging despite changes in sensory input

wet

pressure & cold together

itch

pain and pressure receptors

tickle 

overwhelming pressure receptors

importance of pain

tells the body that something is usually wrong

phantom limb sensations

feeling your limb after them being amputated

2 examples of psychological influences of pain

attention - focusing on pain can make it feel more intense expectations and emotions- your mood,stress level, and expectations can shape how you experience pain

5 basic taste 

sweet(energy source) ,sour(acidic acid) ,salty,bitter,umami

scientific name for smell

olfaction gustation

stimuli

something that causes a response in your brain or body ( loud noise = you jump)

low intensity

rods

in edges of retina (2)

rods (2)

frequently high

cones

center in retina (2)

cones (2)

monochromatic people

see no color

visual capture

vision overrides senses

frequency

pitch

intensity

loud, volume

sensory neural treatment

cochlear implant

conduction

mechanical hearing aid

cilia

little hair in cochlea

ear wax

keeps ear canal clean

ear drum

barrier between outside and inside ear

taste

gustation