chapter 6 Flashcards
what is sensation
The awareness of properties of an object or event when a sensory receptor is stimulated
what is perception
The act of organizing and interpreting sensory input as signaling a particular object or event
what is psychophysics
Studies of the relationship between physical stimuli and the sensation & perception that those stimuli effect.
what is an absolute threshold
the minimum stimulus energy needed to detect a particular stimulus 50 percent of the time
what is the difference threshold (JND)
the minimum difference between two stimuli required for detection 50 percent of the time. We experience the difference threshold as a just noticeable difference
what is weber’s law
computes the JND; how much does it have to change before we know its changing
Ernst weber
what is the stimulus for vision
light stimulus= the photon
what are the properties of light
wavelength, amplitude, frequency
what are the structures of the eye
pupil
iris
cornea
retina
fovea
optic nerve
lense
what does the pupil do
lets light in
what does the iris do
determines how much light is let in
what does the cornea do
protects eye, refracts light
what does the retina do
photoreceptors (rods + cones)
*Rods (100-120 million)
* Very sensitive to light
* Only register shades of gray
*Cones (5-6 million)
* Sensitive to particular
wavelengths
* Allow color vision
what is the fovea
where light needs to hit to see
what is the optic nerve
where information leaves the eye
what does the lense do
flattens or fattens aka bends light in order to make it to fovea
what is the Young-Helmholtz Trichromatic theory
that we have cones in our eyes that see blue, red, and green
what is Herings Opponent process theory
humans perceive color in terms of three opposing color pairs: red versus green, blue versus yellow, and black versus white
theory suggests that one color in a pair suppresses the other, so we see yellowish-greens and reddish-yellows, but not reddish-greens or yellowish-blues.
explains afterimages
what is transduction
cells translate world language to brain language
what is accomdation
when the lense changes shape
what is myopia
nearsighted, eyeball too long
what is hypermetropia
farsighted; light rays come to focus behind retina
what is an astigmatism
shape of cornea is abnormal
what happens when a wavelength is short
high frequency, bluish colors, high pitched sounds
what happens when a wavelength is long
low frequency, reddish colors, low-pitched sounds
what happens when the amplitude is big
loud sounds, bright colors
what happens when the amplitude is small
dull colors, soft sounds
what is the stimulus for audition?
sound waves
what is the middle ear
the chamber between the eardrum and cochlea containing three tiny bones that concentrate the vibrations of the eardrum on the cochlea’s oval window
in slides contain eardrum and bones
what is the inner ear and the cochlea
the innermost part of the ear, containing the cochlea, semicircular canals, and vestibular sacs
a coiled, bony, fluid-filled tube in the inner ear; sound waves traveling through the cochlear fluid trigger nerve impulses
what is the anatomy of the cochlea
In your middle ear, a piston made of three tiny bones picks up the vibrations and transmits them to the cochlea, a snail-shaped tube in your inner ear.
The incoming vibrations then cause the cochlea’s membrane-covered opening (the oval window) to vibrate, jostling the fluid inside the cochlea. This motion causes ripples in the basilar membrane, bending the hair cells lining its surface, rather like grass blades bending in the wind.
The hair cell movements in turn trigger impulses in the adjacent nerve cells, whose axons converge to form the auditory nerve. The auditory nerve carries the neural messages to your thalamus and then on to the auditory cortex in your brain’s temporal lobe. From vibrating air, to tiny moving bones, to fluid waves, to electrical impulses to the brain: Voila! You hear!
what is the place theory
states that our perception of sound depends on where each component frequency produces vibrations along the basilar membrane
high frequency waves in basilar membrane
Dissipates near narrow and
stiff base
low frequency waves in basilar membrane
propagate all the way to apex
how does the primary auditory cortex perceive pitch
high pitched toward front of cortex, low pitch toward back of cortex (tonoptic organization)
what does the auditory cortex do?
Processes complex relevant sounds
* Animal noises
* Footsteps
* Any complex pattern of sound
Mostinterestingsoundsfallintothiscategory,includingspeech,environmental sounds, and background noise.
Fine-tuned by experience
* Language
* Music
* Heschl’s gyrus (Heschl’s gyrus is responsible for processing auditory stimuli like sound frequency, duration, and intensity)
what are the 3 kinds of deafness
central, conduction, sensorineural
what is central deafness
Auditory areas of brain fail to process incoming information * Often due to stroke, tumor or TBI
what is conduction deafness
Sound vibrations cannot be turned into fluid displacement * Often due to fusing of ossicles
what is sensorineural deafness
Hair cells fail to respond to fluid displacement * Often due to permanent damage to hair cells
what is the vestibular system and what does it do
sense off balance;
Motion sickness
* sensory conflict theory: contradictory sensory messages
* Discrepancy between vestibular and visual info
what are the 5 basic tastes
sour, sweet, salty, bitter, umami ( responds to msg)
how do we get distinct flavors?
- Each food stimulates distinct combination of taste receptors
- Smell matters
- Apple vs. Onion
- Temperature & Texture matters * Mood matters
what is the function of the tongue
- Papillae
- Different types
- Each papillae has from one to several hundred taste buds
- (average person has 2000-5,000 taste buds)
- Each taste bud has 50-150 taste receptor cells
where are tastes triggered
*
*
We do not just taste 1 type in one region
For example: sweetness is not just triggered at tip of tongue.
*
* Thresholds
All taste types found in each area.
* Singlepapillaecanbesensitivetojust1tasteat low concentration levels, but at higher levels may be sensitive to more than one taste.
taste receptor cell
- Taste pore
- Small opening on tongue surface where taste cells exposed to
contents of mouth * Taste receptor cells - Undergo constant cycle of growth, change, death, regeneration (lifespan of 1 taste cell = ~ 2weeks)
- Depolarizes/hyperpolarizes in response to chemicals
neural coding of taste
- So how do we distinguish between say 2 different kinds of chocolate? * Answer: In the brain
- Broad response to different tastes
- Can have several taste receptor cells sensitive to different tastes synapse
with gustatory axon (so that axon will fire to different tastes) - Pattern maintained through to the cortex
- Populations of neurons fire together to give us our perception of tastes
what are ambiguous figures
images that can be interpreted in multiple ways, or appear to flip between two different options
what are the gestalt laws
proximity, continuity, similarity, closure, good form
proximity
we group together thiings that are close to each other 3 set of 2, 2 sets of 3
continuity
4 squiggly lines converging looks like 2 crossing each other
similarity
when items share visual characteristics, they are perceived as more related than objects that are dissimilar
closure
when presented with incomplete visual information, our brains tend to fill in the gaps to perceive a complete object
good form
how the human brain perceives objects as complete, regular forms, even when the input is fragmented
what are illusory contours
Visual Illusion due to our brain’s perceptual organization
what is involved in depth perception
binocular cues, monocular cues
what are the binocular cues
*Retinal Disparity * Convergence
*Stereograms
what are the monocular cues
- Monocular cues
- Relative Motion: motion parallax
*Relative Height
*Relative Size - Interposition
*Light and shadow
Linear perspective
