*********************************
There is now a CONTENT FREEZE for Mercury while we switch to a new platform. It began on Friday, March 10 at 6pm and will end on Wednesday, March 15 at noon. No new content can be created during this time, but all material in the system as of the beginning of the freeze will be migrated to the new platform, including users and groups. Functionally the new site is identical to the old one. webteam@gatech.edu
*********************************
Adaptive Shaping of Cortical Response Selectivity in the Vibrissa Pathway in Awake and Anesthetized States
Advisor:
Garrett Stanley, PhD (Georgia Institute of Technology)
Committee Members:
Dieter Jaeger, PhD (Emory University)
Robert Liu, PhD (Emory University)
Anna Roe, PhD (Vanderbilt University)
Chris Rozell, PhD (Georgia Institute of Technology)
The brain is inundated with sensory stimuli every waking hour, yet we efficiently extract relevant information to form perceptions and make decisions. The efficient encoding of sensory information necessarily relies on the ability of the pathway to dynamically shift its operating regime, depending on the context under which external stimuli are processed, be it an environmental cue or internal brain state regulation. One embodiment of context-dependent information processing is sensory adaptation, which has been shown to shape the information flow in the sensory pathway and cortical selectivity to stimulus features. Using voltage-sensitive dye imaging in anesthetized rats and the paradigm of detection / spatial discrimination task by the ideal observer as a model for context-dependent information processing, I first quantify how adaptation shapes the cortical response to a stimulus in the vibrissa pathway and how the information for detecting and spatially discriminating the stimulus is differentially optimized. I further investigate the effect of adaptation in ethologically relevant contexts. Cortical activation and detection-discrimination tradeoff are quantified in relation to the degree of adaptation, which is modulated continuously by the frequency and velocity of the adapting stimulus. Finally, I will generalize the findings to awake animals and investigate the common effects of adaptation under anesthetized and awake states and potential differences in sensory information processing.
