[CTN] Special CTN seminar: Tues Sept 27, Dr. Kerry Walker (University of Oxford, UK)

[Matthijs van der Meer]

Dr. Walker happens to be visiting Waterloo, and she kindly agreed to
give a special CTN seminar next week.

Tuesday Sept 27th, 3.30pm in PAS 2464 (the usual place and time).

Jeff Orchard will be acting as host, so please e-mail
<jorchard at cs.uwaterloo.ca> if you would like to meet with Dr. Walker.

Dr. Kerry Walker
Postdoctoral Research Scientist, Auditory Neuroscience Group, University
of Oxford
Junior Research Fellow, St. Catherine's College

Title: "Sound feature encoding in the auditory cortex"

Abstract:

Our ears detect sound as changes in air pressure over time, yet we would
not describe the process of hearing as one of “perceiving pressure
waves”. Rather, we hear music, a familiar voice, or the rustling of
leaves. The brain categorizes and distinguishes these types of auditory
objects by constructing perceptual features such as pitch (an ordering
of sounds from low to high) and timbre (e.g. the spectral envelope that
defines a sound source). My research investigates how these complex
features are represented as patterns of action potentials in the
auditory cortex of the ferret. We have found that the spike rates of
small ensembles of neurons in auditory cortex can account for ferrets’
pitch judgements. In fact, these neural responses correlate more
strongly with the animal’s choice on a pitch discrimination task than
the acoustic properties of the sound being presented. Furthermore, we
have shown that in a realistic environment where sounds vary
simultaneously in pitch, timbre and spatial location, cortical neurons
can rely on temporally multiplexed spike codes to represent each of
these features independently.