University of Pittsburgh Department of Neuroscience: Special Seminars as part of Faculty Search.

Dr. Alan Emanuel, Harvard University

“Contributions of Peripheral Mechanoreceptor Subtypes to the Cortical Representation of Touch”


Join the Zoom Meeting Here!

CMU Neural Engineering Seminar 

When: Monday, November 29, 2021, 3-4PM ET

Where: Join Zoom Meeting https://cmu.zoom.us/j/92714209784?pwd=VUJkeVZZQUZQT2lxMUtGQVVJcnM1Zz09

Decoding local and global cognitive signals from neuronal populations

Matt Smith, Ph.D.

Associate Professor of Biomedical Engineering and the Neuroscience Institute, Carnegie Mellon University

Abstract: Neural activity observed within a brain area may reflect local computations within the area, inputs from another area, or shared computations/inputs across many areas. Ideally, these distinct mechanisms could be studied separately. However, because multiple processes can influence groups of neurons, it is not obvious how to separate the neural signals that should be attributed to each process. We investigated the different behavioral roles of neural variability shared across hemispheres and neural variability local to each hemisphere. To do this, we applied dimensionality reduction methods to bilateral prefrontal cortex (PFC) array recordings. We were able to identify latent variables representing activity shared across hemispheres, as well as latent variables representing activity local to each hemisphere. We found that variability shared across hemispheres was dominated by a process that slowly evolved across trials and was highly correlated with trial-to-trial fluctuations in mean pupil diameter – a potential neural correlate of fluctuations in arousal. By decoding this signal from neuronal population activity, we were able to predict a constellation of aspects of the animal’s task and eye movement behavior. Overall, our work demonstrates how distributed cognitive processes and states can be hidden in subtle shifts in the responsivity of individual neurons, but accessed and decoded from simultaneously recorded populations of neurons.

About the Speaker: Matt Smith (B.S. Canisius College, Ph.D. New York University) is an Associate Professor of Biomedical Engineering and the Neuroscience Institute. His laboratory studies visual perception, cognition, and decisions. They use a combination of electrophysiological and imaging techniques, combined with computational approaches, to gain insight into how populations of neurons work together to support perception and action.