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Computational Neuroscience Lecture 7. Conor Houghton. PICTURE FROM WIKIPEDIA. PICTURES FROM WIKIPEDIA. The inner ear. CROSS SECTION OF THE COCHLEA. COCHLEA. Outer hair cells amplify. Video of dancing haircell . http://youtube.com/ / watch?v =Xo9bwQuYrRo. Inner hair cells signal.
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Computational Neuroscience Lecture 7 Conor Houghton
PICTURES FROM WIKIPEDIA The inner ear CROSS SECTION OF THE COCHLEA COCHLEA
Outer hair cells amplify • Video of dancing haircell. http://youtube.com/ /watch?v=Xo9bwQuYrRo
Inner hair cells signal • Video about the inner ear, with the sound removed. http://youtube.com/ /watch?v= 1VmwHiRTdVc
Stereocilia of a frog’s inner ear PICTURE FROM WIKIPEDIA
Different hair cells respond to different frequencies – all hair cells respond to sound over a short time window.
Weber’s law • Roughly speaking – effect goes like the log of the cause. • Sort of holds for the auditory system. • Use log|S(k,t)| • SMALL PRINT: The phase information is gone, however, we have overlapping windows and two variables; there are theorems that say we haven’t lost anything.
Spectrogram • Zebra finch song and spectrogram. http://youtube.com/ /watch?v= 5hcKa86WJbg
Spectrogram • Repeat of zebra finch song. http://youtube.com/ /watch?v= 5hcKa86WJbg
Zebra finches http://effieex3.tumblr.com/post/20369494508
From Sen et al. J Neuro 2001
From Sen et al. J Neuro 2001
From Sen et al. J Neuro 2001
So? • Works better than you might expect, particularly in the lower part of the pathway. • Does not give the whole story, particularly further up the pathway. • The calculation is hairy, but seems to work, certainly don’t try to improve it. • The STRFs aren’t quite as revealing as you’d expect.