Psych Sensation and Perception Review

sensation

process by which our sensory receptors and nervous system receive and represent stimuli energies from our environment

• brain receives input from sensory organs

perception

process by which our brains organize and interpret sensory information

• enables us to recognize objects and events as meaningful

• makes sense out of input from sensory organs

bottom up processing

info processing that begins with sensory receptors and works to the brain’s integration of sensory info

top down processing

info processing guided by higher level mental processes

• construct perceptions drawing on experience and expectations

gestalt

explains perceptions in terms of organized whole rather than by analyzing their constituents

• minds tend to perceive object as part of a greater whole and as elements of more complex systems

similarity

gestalt concept: similar things tend to appear grouped together (both visual and auditory stimuli)

pragnanz

gestalt concept: objects in environment are seen in a way that makes them appear as similar as possible

proximity

gestalt concept that things near each other seem to be grouped together

continuity

gestalt concept that point connected by a straight or curving line are seen in a way that follows the smoothest path

closure

gestalt concept that things are grouped together if they seem to complete some entity

gestalt common region/grouping

gestalt concept that elements that are grouped together within the same region of space tend to be grouped together

figure ground

gestalt concept that the organization of the visual field into objects that stand out from their surroundings

transduction

conversion of one form of energy to another

psychophysics

study of relationship between physical characteristic of stimuli (ex. intensity) and out psychological experience of them

absolute threshold

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

signal detection theory

predicts how and when we detect the presence of a faint stimulus among background stimulation

subliminal

stimuli below one’s absolute threshold for conscious awareness

• brain may still respond to stimulus unconsciously

priming

activation (often subconsciously) of certain associations

• predisposes one’s perception, memory or response

difference threshold

minimum difference between 2 stimuli required for detection 50% of the time

• experienced as a just noticeable difference

Weber’s law

to be perceived as different, 2 stimuli must differ by a constant minimum % (not constant amount)

• % varies by stimulus

sensory adaptation

diminished sensitivity as a consequence of constant stimulation

• focuses attention on informative changes to environment

• eyes are always moving to prevent visuals from vanishing

wavelength

distance from the peak of one light wave or sound wave to the peak of the next

hue/pitch

dimension of color of tone of sound that is determined by wavelength of light/sound (known as colors)

intensity

amount of energy in a light or sound wave which influences brightness/loudness

• determined by amplitude

amplitude

height of a light or sound wave

cornea

eye’s clear, protective outer layer covering pupils and iris

• bends light to provide focus

pupil

adjustable opening in center of eye through which light enters

iris

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

• dilates/constricts in response

• responds to cognitive + emotional states

lens

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

retina

light-sensitive back inner surface of the eye

• contains receptors (rods and cones) plus layers of neurons that begin the processing of neural info

accomodation

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

rods

retinal receptors that detect black/white and are sensitive to movement

• necessary for peripheral and twilight vision

cones

retinal receptors that are concentrated near the center of the retina (cluster around the fovea)

• function in well lit-conditions/daylight

• detect fine detail and color sensations

fovea

central focal point in retina

• cones cluster around

optic nerve

nerve carrying neural impulses from eye to brain

blind spot

point at which optic nerves leaves the eye

• no receptor cells (rods/cones) located there

young-helmholtz trichromatic theory

retina contains 3 different types of color receptors which, when stimulated in combination can produce perception of any color

• 3 colors = red, blue, green

opponent process theory

opposing retinal processes enable color vision

• some cells stimulated by red and inhibited by green

• red-green, blue-yellow, white-black

• combination of colors must travel through separate channels

feature detectors

nerve cells in the brain’s visual cortex (occipital lobe) that respond to specific features of the stimulus

• ex. respond to shape, angle, or movement of stimulus

• pass info to cortical areas where supercell clusters respond to more complex patterns

parallel processing

processing multiple aspects of a stimulus or problem simultaneously

• other neural teams integrate results + compare with stored info to enable perceptions

audition

the sense or act of hearing

pitch

tone of sound (how high or low it is)

• depends on frequency

middle ear

chamber between eardrum and cochlea containing 3 tiny bones that concentrate the vibration of eardrum on cochlea’s oval window

hammer, anvil, stirrup

the 3 tiny bones in the middle ear

inner ear

innermost part of the ear

• contains cochlea, semicircular canals, vestibular sacs

cochlea

coiled, bony, fluid-filled tube in inner ear

• sound waves travelling thru cochlear fluid trigger nerve impulses

sensorineural hearing loss

most common form of hearing loss, also called nerve deafness

• caused by damage to cochlea’s receptor cells or auditory nerve

conduction hearing loss

less common form of hearing loss

• caused by damage to mechanical system that conducts sound waves to the cochlea

cochlear implant

device for converting sounds into electrical signals and stimulating the auditory nerve through electrodes threaded into the cochlea

place theory

high frequencies vibrate beginning of cochlea membrane

• theory of how we hear high pitches

frequency theory

neural impulses are sent at the same rate as incoming sound wave

• theory of ow we hear low pitches

volley theory

nerves cannot fire faster than 1000 times per second → neural cells alternate firing for frequencies above 1000 waves per second

• theory of how we hear medium pitches

benefit of 2 ears

sound waves strike 1 ear sooner + more intensity than other

taste

tactile sense → sensitive to pressure, warmth, cold and pain

gate-control theory

spinal cord contains neurological “gate” that blocks pain signals or allows them to pass to brain

• gate opened by activity of pain signals travelling up small nerve fibers

• gate closed by activity of pain signals in large fibers or from info coming from brain

gustation

sense of state

• chemical sense

• aromas interact with info from tast preceptor (bud) cells

sweet, salty, bitter, sour, umami, oleogustus

6 different flavors

olfaction

sense of smell

• no basic sensations

• chemical sense

• DOES NOT PASS THRU THALAMUS (unlike all other senses)

• travels to olfactory bulb and temporal lobe smell cortex

kinesthesis

movement sense

• senses position and movement of individual body parts

vestibular sense

balance sense

• sense of body movement + position that enables sense of balance

• uses semicircular canals and vestibular sacs to sense tilting'/rotation of head (stimulated hair like receptors)

• faster than sight

embodied cognition

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

sensory interaction

principle that one sense can influence another (ex. smell influences taste of food)

selective attention

ability to focus conscious awareness on a particular stimulus

inattentional blindness

phenonemom where people fail to see visible objects when attention is directed elsewhere

change blindness

failing to notice changes in the environment

• form of inattentional blindness

perceptual set

mental predisposition to perceive one thing and not the other

• affects top-down cognition

• schemas prime us to organize and interpret ambiguous stimuli in certain ways

ganglion cells

cells which receive optic info and transmit it to brain for processing

• create optic nerve

• where opponent process theory occurs

nearsightedness

inability to see far away (good vision close up)

farsightedness

inability to see nearby (can see far away)

monochromatism

color deficiency where person only has rods

color deficiency

disorder caused by missing cones or ganglion cells

• red/green most common

dichromatism

color deficiency where person is missing one type of cone

cocktail party effect

phenonemom where you notice your name across the room when its spoken, when you weren’t previously paying attention

binocular cues

a depth cue that depends on the use of 2 eyes

monocular cue

a depth cue available to either eye alone

convergence

eyes strain more as objects draw nearer

• cue to nearby object’s distance

• enabled by brain’s combining of retinal images

retinal disparity

image cast is slightly different on each retina

• location of image helps us determine depth

• brain compares difference in retinal images to compute distance

• greater the difference between the 2 images the closer the object is

interposition

monocular cue where an overlapping image appears closer

relative size

monocular cue where 2 objects that are usually similar in size, the smaller one is further away

linear perspective

monocular cue where parallel lines converge with distance

relative clarity

monocular cue where hazy objects appear further away

texture gradient

monocular cue where coarser/more textured objects are closer

stroboscopic movement

illusion of continuous movement experienced when viewing a rapid series of slightly varying still images

phi phenomenom

illusion of movement created when 2 or more adjacent lights blink on/off in quick succession

autokinetic effect

illusory movement of a still spot of light in a dark room

perceptual constancy

ability and need to perceive objects as unchanging even as changes may occur in distance, point of view, and illumination

• ex. constant color, size, shape, brightness

expectations, emotions, motivations

factors which influences perceptual set

prosopagnosia (face blindness)

a neurological condition characterized by the inability to recognize the faces of familiar people and learn to recognize new ones

pinna

fleshy outside part of the ear

outer ear

part of ear that traps sound waves and channels them through the auditory canal into the eardrum

auditory canal

canal in outer ear

• sound waves travel down this structure and into the eardrum

eardrum

tight membrane that vibrates when sound waves hit it

middle ear

part of ear that transmits eardrum’s vibrations through a piston made of 3 tiny bones to the cochlea

inner ear

part of ear containing the cochlea, semicircular canals and vestibular sacs

• where sound transduction occurs

basilar membrane

membrane inside cochlea which vibrates in response to sound and whose vibrations lead to activity in the auditory pathways

auditory nerve

nerve that sends neural messages (via the thalamus) to the temporal lobe’s auditory cortex

mcGurk effect

perceptual phenomenon which demonstrate an interaction between hearing and vision in speech perception

proprioceptors

sensors that are located in the skin, joints, muscles, and tendons for kinesthesis

oval window

where stirrup attached to the cochlea