BIOMEDICAL
ENGINEERING SEMINAR SERIES
**********************************************************
Dr.
Xiaoqin Wang
Professor
of Biomedical Engineering, Neuroscience and Otolaryngology
Johns
Hopkins University School of Medicine
“Information
Processing in Auditory Cortex”
Thursday,
April 6th, 2006
12:00
Noon
3201
Natural Sciences II
Abstract:
In
contrast to the visual system, the auditory system has longer subcortical
pathways and more spiking synapses between the periphery and cortex. This unique
organization reflects the needs of the auditory system to extract information
from the acoustic environment using strategies different from those used in
other sensory systems. The representations of the acoustic environment in
auditory cortex can be characterized by three types of transformations: 1)
isomorphic (faithful) transformation of tonotopic axis, 2) non-isomorphic
transformation of acoustic features and 3) transformation from acoustic to
perceptual dimensions for auditory object processing. The challenges now facing
auditory researchers are to understand the nature of the latter two
transformations. I will use recent findings from my laboratory to illustrate how
such transformations of acoustic information take place in auditory cortex and
their implications for neural processing of speech and music in the brain. In
particular, I will discuss how the auditory cortex solves the problem of
representing a wide range of time-varying signals and extracts the pitch from
harmonic complex sounds.
Related
Readings:
Wang, X., T. Lu,
R.K. Snider and L. Liang. “Sustained firing in auditory cortex evoked by
preferred stimuli.” Nature 435:
341-346 (2005).
Bendor, D. A. and
X. Wang. “The neuronal representation of pitch in primate auditory cortex.” Nature
436:1161-1165 (2005).
Barbour, D. L. and
X. Wang. “Contrast tuning in auditory cortex.” Science 299: 1073-1075
(2003).
Lu, T., L. Liang
and X. Wang. “Temporal and rate representations of time-varying signals in the
auditory cortex of awake primates.” Nature
Neuroscience 4: 1131-1138 (2001).
Sponsored by
The
Laser Microbeam and Medical Program (LAMMP)
a
NIH biotechnology resource facility
The
Department of Biomedical Engineering
UCI
Center for Hearing Research