Cerebral Systems Laboratory

Cerebral Systems Lab receives 5-year grant from the Natural Sciences and Engineering Research Council of Canada (NSERC)to examine the “Functional Organization of Non-Primary Auditory Cortex”.

Functional specialization is a common characteristic of the cerebral cortex. Globally, regions are specialized to perform particular sensory or motor functions. Within extrastriate visual cortex of humans, monkeys and cats, areas have been identified that are further specialized for spatial, motion, and pattern processing. The behavioral correlate for such functional specializations, or a “division of labor”, within auditory cortex is largely unknown. The long-term goal of the proposed work is to elucidate the behavioral “division of labor” within auditory cortex and determine the relative contributions that the different auditory fields make to acoustically-mediated behaviors. These results, when combined with investigations of underlying cerebral connections, will provide evidence for, or refute, which hierarchical or network theories best explain processing in auditory cortex. In the present study, we will combine a battery of behavioral tests, reversible deactivation, and electrophysiological recording, to dissect the functional plan of auditory cortex.

Cerebral Systems Lab receives 5-year grant from the Canadian Institutes of Health Research (CIHR) to examine “Auditory Cortex Plasticity Following Cochlear Implant”.

In Canada, hearing impairment is the most common sensory disability in adults (affecting 26% of those >45 years old) and deafness is the most common birth defect. Cochlear implants are extremely useful tools in providing auditory sensations to the profoundly deaf and have restored hearing to over 1 million people worldwide. The use of cochlear implants in the profoundly deaf makes human speech comprehension possible. In hearing subjects, acoustic input shapes the development of auditory cortex of the brain. However, in deaf individuals the auditory cortex has no acoustic input. Other senses, such as vision and touch, exploit the unused “deaf” region of cortex for their own purposes. This commonly results in enhanced visual or tactile abilities reported in the deaf. However, if the dormant auditory system is then activated by a cochlear implant, how does “deaf” auditory cortex respond? Does all of “deaf” auditory cortex begin to process sound? Does the visual or tactile processing that invaded “deaf” auditory cortex retreat? Does each auditory cortical area begin to perform the same functions identified in a hearing subject? By better understanding the plastic properties of the brain following cochlear implant, it will be possible to develop implantation strategies to better exploit the plasticity of the brain and improve cochlear implant efficacy and hearing restoration success.