AP PSYCH U#4

sensation

sensation

process by which sensory receptors and nervous system receive stimulus energies from the environment

• raw data/stimulus

• bottom up

bottom up processing

analysis that begins with sense receptors and works up to the brains internation of sensory info

• PNS sends sensory info to CNS

absolute thresholds

weakest amount of stimulus required to produce a consciousness sensation 50% of the time

• right on the border

subliminal stimuli

stimuli that creates sensory stimulation and perception below ones absolute threshold of conscious awareness

difference threshold/Just noticable difference

minimum amount of difference a person can detect between 2 stimuli

webers law

To be sensed as different, 2 stimuli must differ by a constant minimum percentage rather than a constant amount

• 5 v 10

• 105 v 110

  • big difference

weber fraction

the percentage that a stimuli must differ to be perceived as different

sensory adaptation

diminshed sensitivity to a stimulus as a consequence of a constant stimulation by that stimulus

• lights off in darkness

• allows us to experience the world not exactly as it is, but as it is useful for us to experience

senses

Vision, Olfaction, Gustation, Touch, and Audition

transduction

conversion of one form of energy into another

• stimulus from the environment → transduction → neural impulses our brain can interpret

light

electromagnetic energy measured and described in wavelengths

hue

the dimension of the color that is determined by the wavelengths of color

• the actual color

• ex: lemon yellow

intensity

amount of energy in light/sound wave determined by amplitude

parts of the eye

• cornea

• pupil

• iris

• lens

• vitreous humor

• retina

• photoreceptors

• fovea

• bipolar and ganglion cells

• optic nerve

cornea

the dome shaped covering on the front to the eye

• light enters the eye through the cornea

• no blood vessels, transparent

• protection, outermost

pupil

adjusable opening through which light passes

• controlled by iris

iris

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

• bright light = iris expands → pupil constricts

• dim light = iris constricts → pupils expand

lens

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

accomidation

the process by which the lens changes its curvature

vitreous humor

thick, transparent liquid that fills the center of the eye

• mostly water

• gives eye its shape

retina

the light-sensative inner surface of the eye

• contains photoreceptors that transduce light to vision

photoreceptors

rods and cones

rods

allows for peripheral vision, sensitive to the brightness of light, detects black, white and grey

cones

allows for central vision, detects detail and color concentrated in the fovea

fovea

retinas area of central focus where ethem cones cluster

bipolar and ganglion cells

neurons that transduce light waves into neural impulses for the optic nerve

• light to vision

• rods & cones→bipolar cells→ganglion cells→optic nerves

optic nerve

sends neural impulses from the eye to the brain

blindspot

where the optic nerve connects to the eye and there are no photoreceptors

acuity

the sharpness of vision, the ability to see details

• vision charts

• how well you can see

myopia

close objects are seen more clearly than for away

hyperopia

faraway objects are seen more clearly than close

astigmatism

distortion/blurring of the image at the retina

• caused by irregularity in shape of cornea and lens

retinopathy

damage to small blood vessels of the retina that causes to leak blood

• leaking fluid causes blurred vision, blind spots, “floaters”

glaucoma

fluid pressure builds up inside the eye which damages the optic nerve

• results in blurred vision and loss of peripheral vision

macular degeneration

inability to see objects clearly which results in distorted vision and dark spots in the center of field of vision

cataracts

clouding of the lens

• affects acuity and color vision

visual information processing

rods and cones→bipolar and ganglion cells→optic nerve→opposite thalamus→visual cortex in occipital lobe

parallel processing

the brains natural mode of processing several things at once

• brain divides and conquers tasks

color vision

humans have low difference thresholds for color

young - helmholtz trichromatic theory

theory that the retina contains 3 types of cone cells, each responding to a particular wavelengths of light

• short wavelength = blue

• medium wavelength = green

• long wavelength = red

• incomplete theory

color deficiency

when cones in the eye don’t function properly

deuteranomaly

malfunctioning green cone, most common

afterimage

when you view a color for a period of time, and then the color is removed… you see its complimentary color image

opponent-process theory

the ability to perceive color is controlled by 3 receptors complexes with opposite actions that cant be activated at the same time

• one member of the color pair supresses the other

• one at a time

loudness

amplitude of the wave

pitch

a tones experienced highness or lowness, depends on frequency

• slow and far apart v close together and fast

frequency

number of wavelength that pass a point in a period of time

• low pitch - bass

• high pitch - high ringing

outer ear parts

• pinna

• external auditory canal

pinna

outer ear/lobe

• carilage

external auditory canal

channels sound waves to the eardrum

• ear canal

middle ear parts

• eardrum

• ossicle bones

eardrum

thin membrane that vibrates when the sound waves hit it

oscicle bones

• hammer

• anvil

• stirrup

inner ear parts

• cochlea

• basilar membrane

• auditory nerve

cochlea

coiled, bony, fluid-filled tube in the inner ear through which sounds waves trigger nerves impulses

basilar membrane

inner lining of cochlea containing hair cells → stimulates neurons in basilar membrane → transduction to neural impulses

auditory nerve

sends neural impulses from the cochlea to the brain

• opposite thalamus to the temporal lobe

place theory (Helmholtz)

links the pitch we hear with the place where the cochleas membrane is stimulated

• works with frequency theory

frequency theory

the rate of nerves impulses traveling up the auditory nerve matches the frequency of a one, thus enabling us to sense its pitch

• works with place theory

conductive deafness

a reuslt of sound waves being unable to be transfered from the outer to inner ear

• blockage in middle and outer ear

sensorineural deafness

following damage to the inner ear or auditory nerve leading to the brain

• cochlear implant

kennard principle

better to have brain injuries younger in life due to neuroplasticity

olfaction

the sense of smell

chemical sense - smell

odors are composed of chemical molecules which are sensed by olfactory receptor cells

• receptors in nasal cavity (transduction) → olfactory bulb → olfactory nerves → primary smell cortex (temporal lobe)

• doesn’t pass through thalamus

• odors envoke memories because the bulb is connected to the amygdala and he hippocampus

gustation

sense of taste

5 basic tastes

• sweet

• salty

• sour

• bitter

• umami

chemical sense - taste buds

taste buds catch food chemicals via receptors cells sensitive to 5 basic tastes

• chemical-sensitive receptors on taste buds (transduction) → facial nerves → medulla → thalamus → primary gustatory region (temporal lobe)

sensory interaction

flavor

touch

gate-control theory

AB-nerves

C-nerves

kinesthesis/proprioception (6th sense)

vestibular sense (7th)

perception

top-down processing

priming

selective attention/cocktail party effect

visual capture

gestalt psychology

gestalt grouping principles

figure - group relationship

depth perception - Eleanor Gibson

visual cliff

binocular cues

retinal disparity

convergence

monocular cues

relative size

relative height

interposition (occlusion)

linear perspective

texture gradient

relative clarity

light and shadow

relative motion (motion parallax)

phi phenomenon

beta movement

perceptual constancy