Reaction time correlations as a measure of eye-hand coordination Heather Dean Pesaran Lab Center for Neural Science New York University

Interconnected brain areas may interact to plan and initiate coordinated movements

How are arm movements coordinated with eye movements? Getting at interacting circuits through behavior

Correlated Reaction Times Std SRT: 37 ms Std RRT: 41 ms R = 0.55

There are several stages in movement preparation Variability in RT is due to variability in the duration of these stages

Shared sensory processing attention/arousal

Stimulus Onset Asynchrony Task Delay reach with respect to saccade up to 600 ms. This will disrupt coordination but not arousal.

SOA is the time between movement go cues

RT Correlations are not due to arousal Correlations between SRT and RRT decrease with increasing time between movements.

Shared sensory processing attention/arousal

Overlap in plans Overlap is defined as the time between the start of the saccade and the cue to begin planning the reach.

RT correlations are nonzero when movement plans overlap Correlations between SRT and RRT increase with increasing time of plan overlap.

Interacting Movement Planning

Accumulating Process Model

Summary For movement of two effectors, correlations of RTs can show us how coordinated movements are. When hand and eye movements are made separately, RT correlations disappear. The degree of correlation seems to depend on the overlap between movement plans. Simultaneous multiple area recordings will let us identify neural mechanisms for coupling movement plans

Acknowledgements Pesaran Lab Eva Tsui Bridget DiPrisco Funding Patterson Trust Swartz Foundation Burroughs-Wellcome Fund Bijan Pesaran Alfred P Sloan Foundation