Alex Brandmeyer on High-frequency Neural oscillations for Auditory Perception
Date:
Fri, 05/22/2015 - 11:30am - 1:00pm
Location:
CCRMA Seminar Room (Top Floor of the Knoll)
Event Type:
Hearing Seminar Neural oscillation is a phenomenon in which periodic fluctuations in electrical field potentials are observed at different characteristic frequencies when measuring the activity of large populations of neurons, using both invasive methods, such as laminar electrode recordings in animals or electrocorticography (ECoG) in humans, and non-invasive methods such as electroencephalography (EEG) and it’s magnetic equivalent, magnteoencephalography (MEG). Current theories suggest that neural oscillations serve both to entrain our perceptual activity to temporally structured events in the environment and to coordinate communication across different functional networks in the central nervous system at multiple spatiotemporal scales.
Following a review of recent findings on the role of these oscillations in auditory perception, the results of a recent MEG study on the neural encoding of auditory feature information will be presented. In this experiment, listeners judged complex synthetic stimuli along two feature dimensions in distinct task settings: a global pitch feature (high/low), and a local frequency modulation feature (up/down). A key finding was that the early encoding of sensory information, as indexed by the power of high-frequency oscillations in the gamma band, was differentially lateralized over left and right auditory cortices, depending on which of the two tasks was being performed. This suggests that attention to specific features of complex auditory stimuli biases bottom-up processing of sensory information in functionally distinct regions of cortex. These findings will be linked back to work on the role of gamma-band oscillations in multimodal sensory processing and object representation.
Bio: Alex Brandmeyer obtained his Bachelor’s degree from UC Berkeley, and his MSc and PhD from the Donders Institute for Brain, Cognition and Behavior in Nijmegen, the Netherlands. Following the completion of his dissertation, he worked as a Postdoc at the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig, Germany in the ‘Auditory Cognition’ research group. Currently, he is a Staff Scientist at Dolby Laboratories in San Francisco. His recent work has focused on the use of EEG and MEG measures to understand cortical processing of sound information, the formation of auditory representations and how these processes are shaped by learning and expertise.
FREE
Open to the Public