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250 Cards in this Set
- Front
- Back
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explain condensation in terms of loud speakers [diaphragm]
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diaphragm of speaker moves out pushing air molecules together
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explain rarefaction in terms of loud speakers [diaphragm]
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diaphragm of speaker moves in pulling aire molecules apart
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pure tones occur when pressure changes in the air occur in what type of pattern?
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sine waves
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what's the frequency?
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number of cycles of alternating high and low pressure regions within a given time period
Hz |
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what's the perception of frequency?
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pitch
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what is tone height?
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the increase in pitch that happens when frequency is increased
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what does the audibility curve show?
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threshold of hearing
humans most sensitive to 2,000-4,000 Hz but can hear between 20-20,000 Hz |
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what does the audibility response area show?
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we hear tones that fall within this area. at intensities below audibility curve we can't hear a tone
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what does the equal loudness curve demonstrate the relationship of?
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between loudness and frequency. indicate the number of dB that create the same perception of loudness at different frequencies
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repetition rate of a complex tone
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fundamental frequency
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periodic complex tones consist of a number of....
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pure tones
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how can we build a complex tone?
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using additive synthesis in which a number of sine wave components are added together to create the complex tone. add harmonics
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what's the starting point for creating a complex tone by additive synthesis?
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single pure tone which has a frequency equal to a complex tone's fundamental frequency
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how is timbre created?
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partially by the multiple frequencies that make up complex tones
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increase sound level by 10 dB- how does it affect loudness?
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doubles loudness
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what's the perception of amplitude?
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loudness
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perceptual experience of increased pitch that accompanies increase in a tone's fundamental frequency:
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pitch
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notes with the same _____ have fundamental frequencies that are multiples of one another
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chroma
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how does removing the fundamental frequency affect the wave?
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pitch stays the same; it changes a tone's waveform but not its repetition rate.
it changes timbre |
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what's the quality that distinguishes b/w 2 tones that have the same loudness, pitch, and duration but still sound different?
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timbre
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what's closely related to harmonic structures of a tone?
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timbre
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what does timbre depend on?
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the tone's steady-state harmonic structure and on the time course of the attack and decay of tone's harmonics
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outer and middle ear are filled with:
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air
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what act to amplify vibration for better transmission of vibrations from air to fluid in inner ear?
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ossicles
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main structure of inner ear:
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cochlea
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what sets the cochlea into vibration?
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stapes [stirrup]
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how is the cochlea divided?
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scala vestibuli on top an scala tympani.
divided by cochlear partition |
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what contains the organ of corti?
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cochlear partition
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in the organ of corti what vibrates in response to sound and also supports the organ of corti?
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basilar membrane
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what are the receptors for hearing?
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inner and outer hair cells
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what extends over hair cells in the organ of corti?
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tectorial membrane
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why do cilia bend on top of hair cells in the organ of corti?
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the in and out movement of the stapes creates pressure changes in the liquid inside to cochlea that sets the cochlear partition into up and down motion
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what increases vibration of basilar membrane?
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outer hair cells
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movement of outer hair cells in 1 direction opens channels in the membrane and ions flow into cell. this creates:
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electrical signals that result in teh release of neural transmitter from inner hair cell
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when cilia bend in other direction:
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the ion channels close so electrical signals aren't generated
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explain the entire sensory transduction in general terms [flow]
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airborne sound
movement of eardrum movement of ossicles movement of oval window creates fluid-borne pressure waves and displacement of basilar membrane stimulation of hair cells |
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hair cells all along cochlea send signals to nerve fibres that combines to form:
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auditory nerve
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low frequency causes max activity where on the cochlea?
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apex
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high frequency causes max activity where on the cochlea?
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base end
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physical properties of basilar membrane
base: near stapes compare width and flexibility of base to apex |
base: 3-4x narrower than at apex
100x stiffer than at apex |
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what does the spinal lamina do?
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supporting structure that makes up for the basilar membrane's difference in width at base and apex ends of cochlea
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what are used to determine threshold for specific frequencies measured at single neurons?
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pure tones
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what is auditory masking?
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ability to hear a sound is decreased by presence of other sounds
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what's the frequency analyzer?
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cochlea
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what is the cochlear amplifier?
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actions of outer hair cells
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pathway from cochlea to cortex:
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cochlear nucleus
superior olivary nuclei [brain stem] inferior colliculus [midbrain] medial geniculate nucleus [thalamus] primary auditory receiving area A1 [temporal lobe] SONIC MG |
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processing in superior olivary nuclei is important for determining:
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auditory localization
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auditory areas in the cortex:
neural signals travel through: |
the core, then belt, then parabelt area
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simple sounds cause activation of:
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core area
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which areas are activated in response to more complex stimuli of many frequencies?
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belt and parabelt areas
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what does the WHAT/ventral stream do?
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identifies sounds
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where does the WHAT/ ventral stream start?
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in anterior portion of the core and belt and extends to the prefrontal cortex
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what does the WHERE/ dorsal stream do?
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locates sounds
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where does the WHERE/ dorsal stream start?
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in posterior core and belt and exts to parietal and prefrontal cortices
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in A1 the neurons that respond better to low frequencies are on the:
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left
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in A1 the neurons that respond better to high frequencies are on the:
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right
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auditory cortex is important for discriminating between different:
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frequencies
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tasks that require pitch recognition activate:
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core area
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tasks that require recognition of complex stimuli activate areas:
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parabelt area
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pitch perceived when fundamental frequency is removed [pitch stays the same, timbre changes]
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periodicity pitch
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locating an object in space based on their source
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auditory localization
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surround an observer and exists wherever there is sound. perceive object located at different positions based on their sounds.
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auditory space
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position left to right
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azimuth coordinates
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position up and down
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elevation coordinates
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position from observer
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distance coordinates
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location cues based on the comparison of the signals received by the left and right eaers
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binaural cues
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interaural time difference: ITD
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difference between the time sounds reach the 2 ears
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when the source is to the side of observer:
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times will differ [ITD]
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Interaural Intensity [level] difference: ILD
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difference in sound pressure level reaching teh 2 ears
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ILD: reduction in intensity occurs for ______frequency sounds for the far ear
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high frequency
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ILD: for high frequencies head casts an
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acoustic shadow
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disruption of high frequency waves creates a decrease in sound_______ on the far side of the head
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sound intensity
--> acoustic shadow |
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ITD provides info about______ of ______frequency sounds
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info about location of low frequency sounds
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ILD provides info about _______of ______frequency sounds
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info about location of high frequency sounds
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ITD & ILD judge what kind of locations
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aziumuth NOT ELEVATION
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monaural cues: what affects intensities of frequencies?
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pinna and head
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this is a spectral cue since info for location comes from spectrum of frequencies
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head-related transfer function
HRTF |
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the differences caused by the fact that before the sound stimulus enters teh auditory canal it's:
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reflected from teh head and within various folds of the pinna
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differences in the way the sounds bounce around within the pinna create:
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different frequency spectra for 2 locations [with same ITD & ILD]
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spectral cues work best for judging:
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elevation at high frequencies
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neurons in inferior colliculus and superior olivatry nuclei that respond to a range of ITDs
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narrowly tuned ITD neurons
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a specific ITD activates neurons tuned to that ITD is a form of
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specificity coding
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Jeffress Model
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series of neurons that each respond best to a specific ITD these neurons are wired so that they each receive signals from 2 ears.
- source directly in front- waves reach at same time and signals start from each each start together. as they travel down the axon it stimulates each neuron in turn at beginning of journey - neurons receive signals from only left or right and they don't fire |
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distributed coding model- info in nervous system is based on the pattern of neural responding
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broadly tuned ITD neurons
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interaural time difference detectors
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neurons that respond to specific interaural time differences
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where are interaural time difference detectors located?
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in auditory cortex and at first nucleus [superior olivary nucleus] on system that receives input from both ears
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what type of neurons signal location by their pattern of firing
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panoramic neurons
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the where/dorsal stream shows more specific neural response for location where?
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the further upstream the neurons are located in teh cortex
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array of all sound sources in the environment
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auditory scene
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process by which sound sources in the auditory scene are separated into individual perceptions
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auditory scene analysis
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heuristics of auditory grouping:
location |
single sound source tends to come from 1 location and to move consistently
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heuristics of auditory grouping:
similarity of timbre and pitch |
similar osunds are grouped together
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heuristics of auditory grouping:
proximity in time |
sounds that occur in rapid succession usually come from same source
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heuristics of auditory grouping:
good continuation |
sounds that stay constant or change smoothly: same source
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heuristics of auditory grouping:
experience |
listen for melodies: melody schema
vs jumble of notes |
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where are the mechanoreceptors located?
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dermis
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mechanoreceptor:
fires continuously as long as pressure is applied. senses fine details. disk shaped. |
Merkel receptor
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mechanoreceptor
stack of flattened disks in the dermis, fires only when pressure is applied and removed, controls hand grip |
Meissner corpuscle
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mechanoreceptor
branched wires inside a cylindrical capsule. responds continuously to stimulation, perceives stretching of skin |
Ruffini cylinder
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mechanoreceptor
onlion like capsule deep in skin. responds when stimulus is applied and removed. senses rapid vibrations and fine texture |
Pacinian corpuscle
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what type of fibres are found in Merkel receptors and Ruffini cylinder receptors that fire continuously as long as pressure is applied?
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Slowly adapting fibres
SA |
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what type of fibres are found in Meissner corpuscle and Pacinian corpuscle receptors that fire at onset and offset of stimulation?
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rapidly adapting fires RA
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what responds to pattern of grooves?
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SA1 fibres, Merkel receptors
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what doesn't respond to the details of patterns of grooves stimuli?
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RA2 fibres
Pacinian Corpuscle |
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what's the frequency range?
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3 Hz for SA1 fibres to 500 Hz for RA2 fibres
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what's the bundle of nerve fibres that travel to the spinal cord?
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peripheral nerves
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what are the 2 major pathways in the spinal cord?
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medial lemniscal pathway
spinothalamic pathway |
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what does the medial lemniscal pathway consist of?
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large fibres that carry proprioceptive and touch info
signals related to sensing position of limbs [proprioreception] and perceiving touch |
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what does the spinothalamic pathway consist of?
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smaller fibres that carry temp and pain info
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what do the nerve fibre bundles to? how do they travel?
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cross over to opposite side of the body adn synapse in the thalamus. most synapse in ventrolateral nucleus in teh thalamus but some synapse in other thalamic nuclei [LGN-vision; MGN-hearing]
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signals travel from teh thalamus to the:
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somatosensory receiving area: S1 and the secondary receiving area: S2 in teh parietal lobe
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focal dystonia
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musician's cramp
loss of skilled hand movement due to fused cortical areas belonging to affected hand |
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what are 2 ways to measure tactile acuity?
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1. 2 point threshold
2. grating acuity |
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describe the 2 point threshold
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minimum separation needed b/w 2 points to perceive them as 2 units
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describe grating acuity
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placing a grooved stimulus on teh skin and asking the participant to indicate the orientation of the grating
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there's a high density of what type of mechanoreceptor in the fingertip?
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Merkel receptor: SA1
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Merkel receptors are:
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sensitive to details
get better acuity with less spacing |
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areas with high acuity are:
- represented how in the cortex - have what type of receptive fields? |
-larger areas of cortical tissue devoted to them [homunculus]
-smaller receptive fields on skin |
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what type of mechanoreceptor perceives vibration?
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pacinian corpuscle: RA2
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what are the 2 types of cues to perceive texture?
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1. spatial cues
2. temporal cues |
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describe spatial cues
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determined by size, shape and distribution of surface elements. caused by large surface elements [bumps and grooves] that can be felt both when the skin moves across the surface elements adn when it's passed onto the elements [braille, comb]
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describe temporal cues
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determined by the rate of vibration as skin is moved across finely textured surfaces. . provide info in form of vibration that occur as a result of movement over a surface.
perception of fine features |
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perception of coarse textures:
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spatial cues
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perception of fine textures:
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temporal cues
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what systems are involved in active touch?
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-sensory system: detecting cutaneous sense [touch, temp, texture]
- motor system: ove hands - cognitive system: think abt info provided by sensory and motor systems |
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exploratory procedures:
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-lateral motion
-pressure -enclosure -contour following |
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firing pattern of groups of mechanoreceptors signals:
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shape [curvature of object]
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what shows cells that respond to centre-surround receptive fields
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thalamus
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what cortex shows cells that respond maximally to orientations and directions of movement
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somatosensory cortex
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somatosensory neurons respond best to:
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- grasping specific objects
- paying attn to the task |
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unilateral neglect
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denies ownership of limbs on 1 side of the body [parietal lobe-visual/somatosensory damage]
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define pain
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multimodal phenomene containing a sensory component and an affective or emotional component
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3 types of pain
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1. nociceptive
2. inflammatory 3. neuropathic |
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describe nociceptive pain
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signals impending damage to skin
types respond to heat, chemicals, severe pressure, and cold threshold of eliciting receptor response must be balanced to arn of damage but not be affected by normal activity |
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descrbie inflammatory pain
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caused by damage to tissues or joints that releases chemicals that activate nociceptors
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describe neuropathic pain
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caused by damage to CNS
stroke causing brain damage repetitive movements [carpal tunnel] |
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signals from nociceptors travel up teh spinothalamic pathway and activate:
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-subcortical areas including hypothalamus, limbic system, and the thalamus
- cortical areas S1 & S2 in somatosensory cortex, teh insula, and anterior cortex - ---> pain matrix |
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what affects pain?
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-expectation
-shifting attention -content of emotional distraction -individual differences |
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what makes up the gate in the gate control model of pain perception?
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substantia gelatinosa cells in spinal cord
SG- and SG+ |
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where does input into gate come from?
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-large diameter L fibres: info from tactile stimuli
-small diamter S fibres: info from nociceptors -central control: info from cognitive factors from cortex |
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pain doesn't occur when gate is closed. when is gate closed?
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stimulation into SG- from central control on L fibres into the T cell
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pain does occur from stimulationi from the:
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S fibres into the SG+ into the T cells
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give me the low down on S fibres.
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acitivy in S fibres increases activity of transmission T cell. intensity of pain is determined by amount of T cell activity with more activity resulting in more pain. the paths along which signals from teh S travel down excitatory ones. signals from S fibres always excite T cells and increase pain
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lay it down on L fibres:
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nonpainful tactile stimulus signals sent form skin rubbing activity in teh L fibres can send inhibition to the T cells this occurs bc signals that pass thru SG activate an inhibitory synapse this closes gate which decreases T cell activity and decreases pain
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what's up with central control?
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fibres contain info related to cognitive function [expectation, attention, distraction] carry signals down from teh cortex
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how is the perception of pain determined?
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balance between input from nociceptors in teh skina nd nonnociceptive activity from teh skin and brain
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Stern & McClintock experiment:
secretions from donors taken at beginning of their cycles affect recipients how? |
led to a shortened length of recipient's cycle
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Stern & McClintock experiment:
secretions from ovulatory phase affected recipients' cycles how? |
lengthened recipient's cycle
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why do different species smell better or more?
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individual receptors for all animals are equally sensitive so the difference lies in the number of receptors they have
humans: 10 million dogs: 1 billion |
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what's the difference threshold?
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smallest difference in concentration that can be detected between 2 samples.
threshold is at 11% |
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what's the recognition threshold?
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concentration needed to determine quality of an odourant
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how many odours can humans discriminate?:
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100,000
trouble naming: recollection problems |
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what are the 6 corners of Henning's Odour prism?
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6 corners with the qualities putrid, etheral, resinous, spicy, fragrant, and burned
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how does Schiffman's odour space work?`
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odours are arranged such that the distance between 2 indicates their similarity
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where is the olfactory mucosa located?
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top of nasal cavity
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where are the receptors contained in the olfactory mucosa?
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the cilia of sensory neurons
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how many types of olfactory receptors have and how do they work?
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350 types of receptors each expressing a protein that crosses the membrane seven times
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give a general overview of the flow of signals/information in olfactory system
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- odourants flow over mucosa
- olfactory receptor neurons [ORNs] are activated - signals are sent to glomeruli in olfactory bulb signals sent to higher cortical area |
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where are olfactory signals sent to after the signals are carried to the glomeruli in teh olfactory bulb?
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- then sent to primary olfactory [piriform] cortex in temporal lobe
- secondary olfactory [orbitofrontal cortex] in front lobe - amygdala deep in cortex |
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odourants are coded by combinations of olfactory receptors called:
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recognition profiles
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how many different types of ORNs in mucosa?
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350
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how many of each type of ORN in mucosa?
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10,000
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how many different types of olfactory receptors does each ORN have?
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one type of olfactory receptor
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what's the pattern of activation?
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the odourant's recognition profile
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the idea that an odourant's smell can be related to different response profiles is similar to what theory in vision?
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trichromatic theory of colour vision
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each odourant is coded by a different pattern of firing of ORNs and a particular ORN respond to
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many odourants
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activation of receptors in mucosa causes electrical signals in ?
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ORNs that are distributed across the mucosa
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ORNs send signals where?
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glomeruli in the olfactory bulb
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all of the 10,000 ORNs of a particular type send signals to how many glomeruli
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1 or 2 glomeruli
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each glomeruli collects info about?
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firing of a particular type of ORN
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what determines general area of olfactory bulb that's activated?
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functional group
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what determines the position within the area of the olfactory bulb?
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chain length
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what area is involved in the process of perceiving complex odours?
t discriminates between different odours |
piriform cortex
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when perception of pleasantness changes [cheese vs body odour] and the pattern of ORN firing is still the same what reflects the difference?
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orbitofrontal cortex activity
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5 basic tastes:
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1. salty
2. sour 3. sweet 4. bitter 5. umami |
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what are the 4 types of papillae on the tongue?
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1 filiform
2 fungiform 3 foliate 4 circumvallate |
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describe the filiform
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shaped like cones and located over entire surface.
only papillae with no taste buds |
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describe the fungiform
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shaped like mushrooms, found on sides and tip
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describe the foliate
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series of folds on back and sides
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describe the circumvallate
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shaped like mounds at back
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how many taste buds?
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10,000
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each taste bud has taste cells with tips that extend where?
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into taste pore
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when does transduction occur?
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when chemicals contact receptor sites on tips of taste cells on taste buds
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electrical signals generated in teh taste cells are transmitted from the tongue in a number of different nerves [name 4]
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1. chroda tympani nerve [from taste cells on teh front and sides of tongue]
2. glossopharyngeal nerve 3. vagus nervoe [from mouth and throat] 4. superficial retronasal nerve [soft palette on top] |
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what is the perception of flavour?
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combination of smell, taste, and other sensations
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odour stimuli from food in mouth reachs the olfactory mucosa through:
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the retronasal route
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where are the responses from taste and smell first combined?
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orbitofrontal cortex
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where does the orbitofrontal cortex also receive input from?
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primary somatosensory cortex and the inferotemporal cortex in visual what pathway
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what type of neurons are present in the orbitofrontal cortex due to convergence of neurons from different senses?
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bimodal neurons
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the firing of neurons in the orbitofrontal cortex reflects:
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the extent to which an animal will consume a particular food
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the responses of neurons in the OFC reflect:
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the pleasantness of flavours and help control food intake
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vision sends to what area following what path to ultimately end up at the orbitofrontal cortex?
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vision sends to the V4 area following the IT cortex what pathway to reach the OFC
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taste sends to what area then to where to ultimately end up at the orbitofrontal cortex?
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taste sends signals to the thalamus then to the primary taste cortex and ends up at OFC
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olfaction sends signals to what and then to where to ultimately end up at the OFC?
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olfaction sends to the olfactory bulb and then to the primary olfactory cortex and ends up at the OFC
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touch sends signals to what and then where to ultimately end up at the OFC?
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touch sends signals to the thalamus and then to the primary somatosensory cortex and ends up at the OFC
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odourant molecules released by food in oral cavity and pharynx travel through what to reach the olfactory mucosa in nasal cavity by following teh retronasal route to olfactory receptors?
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through the nasal pharynx
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measure neural responses to a visual stimulus
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visual evoked potential VEP
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visual acuit of infants at birth:
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20/400
must view a stimulus from 20 ft away to see same thing as adult at 400 ft |
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when is full visual acuity reached by?
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1 year
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what are 2 reasons for low visual acuity at birth?
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1. visual cortex not fully developed
2. shape and size of cones aren't fully developed |
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compare a newborn's cones to an adult's cones
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fat inner segments and very small outer segments. adults have inner and outer segments of same width
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what does the small size of a newborn's outer segment of the cone tell us?
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newborn's cones contain less visual pigment therefore they don't absorb light as effectively as adult cones
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what does the fat inner segment of a newborn's cone create?
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coarse receptor lattice with large space between segments
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what do adult inner segments do when they become thin?
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pack closely together to create a fine lattice that is well united to detect fine detail
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cone receptor's outer segments cover what percent of adult fovea and what percent of a newborn's fovea?
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68% of adult fovea
2% of newborn fovea |
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contrast to sensitivity measured by determining
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the smallest difference b/w light and dark bars of a grating that can be detected
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spatial frequency
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number of cycles per grating per visual angle
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contrast sensitivity function plot of
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contrast sensitivity vs spatial frequency
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infants can only perceive contrast at what type of frequencies?
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low frequencies
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at low frequencies infants contrast sensitivity is _______x ______ than an adults
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20-100x lower than an adults
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infants can see little or nothing above ____cycles/degree
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2-3
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spatial frequency depends on both
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fineness of the grating and the distance from which it is viewed
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determining the contrast sensitivity of gratings with different spatial frequency result in a plot of contrast sensitivity vs spatial frequency
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contrast sensitivity function CSF
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adults most sensitive to gratings with a spatial frequency of
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3 cycles/ degree
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see high spatial frequency drops off rapidly above
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10 cycles/degree
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due to the underdeveloped state of fovea forces it to see primarily with
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rod-dominated peripheral retina
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habituation method
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infants more likely to look at novel stimulus
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as one stimulus is presented repeatedly infant looking time
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decreases
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once habituation occurs a new stimulus is presented if the infant can distinguish b/w the stimuli
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dishabituation will occur
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what helps infants with perception of object unity?
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movement
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intermodal perception
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coordination of info from different senses into a perceptual whole
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describe the fibrous tunic
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white dense inflexible material: protective coat
bulges in front and turns into transparent cornea cornea draw nutrients from the anterior chamber containing the aqueous humour 80% of focusing: forms a clear image on the retina |
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describe the vascular tunic
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most the heavily pigmented spongy structure: choroid
nourishes entire eye [esp retina] reduces light scatter due to its dark pigmentation in the anterior chamber it turns into the ciliary body producing the aqueous humour |
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describe the iris
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formed from the ciliary body in the anterior chamber
2 layers: outer pigmented layer- circular muscle inner vascularised layer- radial muscle regulate amt of light received by light thru the pupil and the depth of field |
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describe the lens
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1. an elastic covering or capsule
2. an epithelial layer just inside the capsule 3. lens field because of its elastic nautre the optical power can be varied to accommodate for near and far vision *aging causes sclerosis of lens |
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describe the vitreous chamber
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2/3 of volume of eye
bounded by the lens and the retina this chamber is filled with a transparent fluid called vitreous |
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describe the retina
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innermost of 3 layers
3 layers: 1. retinal ganglion cells 2. collector [bipolar, amacrine and horizontal cells] 3. photoreceptors [rods and cones] |
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where is vision most acute?
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macula located at centre of the retina
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what accounts for 80% of focusing? the other 20%
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cornea: 80% [fixed]
lens: 20% [adjusts shape for object distance] |
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how does accommodation work?
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ciliary muscles are tightened which causes lens to thicken
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distance of near point at:
20 50 60 70 |
20: 10 cm
50: 40 cm 60: 100 cm 70: 400 cm |
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what are the 2 components of visual pigment molecules?
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opsin: large protein
retinal: light sensitive molecule |
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when does visual transduction occur?
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when retinal absorbs 1 photon
retinal changes it shapes [isomerization] opsin crosses disc membrane 7 times |
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process needed for transduction:
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-retinal molecule changes shape after absorbing 1 photon of light
-opsin molecule separates -retina shows pigment bleaching -retinal and opsin must recombine tor respond to light |
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how long does a cone pigment take to regenerate?
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6 minutes
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how long does a rod pigment take to regenerate?
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over 30 minutes
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what's the purkinje shift?
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enhanced sensitivity to short wavelengths [blue] durking dark adaptation when teh shift from cone to rod vision occurs
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rod pigment absorbs best at what wavelength?
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500 nm
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cone pigments absorb best at:
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419, 532, 558
avrage: 560 nm |
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rods and cones send signals VERTICALLY through:
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bipolar cells
ganglion cells ganglion axons [optic nerve] |
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rods and cones send signals HORIZONTALLY through:
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horizontal cells
amacrine cells |
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how many rods and cones each converge onto a ganglion cell?
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120 rods to one ganglion cell
6 cones to 1 ganglion cell |
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cones in fovea have what ratio to ganglion cells
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1:1
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signals can travel between receptors through?
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horizontal cells
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signals can travel between bipolar and ganglion cells through?
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amacrine cells
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brightness
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variations in intensity of light sources
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lightness
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perception of reflectance
high reflectance: white low reflectance: black |
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cortical magnification factor
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apportioning the small fovea with a large cortical area
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optic ataxia
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parietal lobe damage who have trouble reaching for objects and forming their hands to grasp them
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4 ways to perceive motion:
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1. real movement
-object physically moving 2. apparent movement -stationary stimuli presented in different locations 3. induced movement -movement of one object makes a stationary object look like it's moving in opposite direction (moon and clouds) 4. movement aftereffect -moving object. stationary object. appears to move in opposite direction |
