Lecture 19 Hearing in the Environment Flashcards
How are ITD values calculated based on tuning curves?
time to reach ipsilateral ear minus time to reach contralateral ear
What do positive ITD values on the tuning curve represent?
neurons that respond best to sounds that reach the CONTRALATERAL ear first
What do negative ITD values on the tuning curve represent?
neurons that respond best to sounds that reach the IPSILATERAL ear first
Why might IT tuning curves be broader in mammals than in birds?
- mammals use population coding to encode ITD (to localize sound)
- birds use specificity coding
TRUE or FALSE: neurons in the left hemisphere are tuned to respond most strongly to sounds reaching the left ear first
FALSE: LEFT hemisphere respond more strongly to sounds reaching RIGHT ear first
Area A1 is involved in ____________.
locating sound
What resulted when cat A1 areas were destroyed?
sound localization ability LOST
What resulted when ferret A1 was destroyed?
sound localization ability DECREASED
What resulted when cat A1 was cooled?
sound localization ability DECREASED
TRUE or FALES: the anterior belt area is also involved in locating sound
FALSE: the POSTERIOR BEST area involved in sound localization
TRUE or FALSE: posterior belt tuning curves are narrower than A1 tuning curves
TRUE (posterior belt single cell recordings revelaed neurons that only respond to sounds coming from particular locations in space –> SPECIFIC)
TRUE or FALSE: when the cat posterior belt was cooled, ability to differentiate 2 patterns of sound was impaired, but localization ability remained intact
FALSE: localization decreased; ability to differentiate 2 patterns intact
TRUE or FALSE: the posterior belt is involved in perceiving more complex sound
FALSE: anterior belt for complex sounds
What resulted when the cat anterior belt was cooled?
ability to differentiate between 2 patterns of sound decreased (localization unaffected)
Where, or dorsal stream, extends from the ________________ to the ____________ and ______________.
posterior belt; parietal lobe; frontal cortex
What, or ventral stream, extends from the ___________________ to the ___________________ and ______________.
anterior belt; temporal lobe; frontal cortex
What are the 2 kinds of sound waves that reach your ears?
direct and indirect sounds
What is a direct sound?
sound that reaches the listener’s ears straight from the source
What is an indirect sound?
sound that is REFLECTED off environmental surfaces and then to the listener