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Behavioral/Systems/Cognitive Neural Dynamics in Monkey Parietal Reach Region Reflect
 

Summary: Behavioral/Systems/Cognitive
Neural Dynamics in Monkey Parietal Reach Region Reflect
Context-Specific Sensorimotor Transformations
Alexander Gail1,2 and Richard A. Andersen2
1Bernstein Center for Computational Neuroscience Gošttingen, German Primate Center, 37077 Gošttingen, Germany, and 2Division of Biology, California
Institute of Technology, Pasadena, California 91125
We investigated the neural dynamics of sensorimotor transformations in the parietal reach region (PRR) of monkeys. To dissociate
sensory from motor goal representations, we used a memory-guided anti-reach task. The monkeys had to reach either to a visually
instructed, memorized peripheral target position (pro-reach) or to a diametrically opposed position (anti) while keeping central ocular
fixation. Pro- and anti-reaches were randomly interleaved and indicated by a color instruction from the beginning of each trial. We
analyzedspatiotemporalsingle-celltuningandperformedtime-resolvedpopulationdecodingtoquantifythedynamicrepresentationof
the spatial visual cue, the reach goal, and the currently valid task rule (pro/anti mapping). Sensory information regarding the visual cue
positionwasrepresentedweaklyduringashortperiodofcuevisibility.PRRpredominantlyencodedthereachgoalfromtheendofthecue
period on. The representation of the reach goal in the memory task evolves later for the anti- compared with pro-reaches, consistent with
a40­50msdifferenceinreactiontimebetweenthetwotaskrules.Thetaskrulecouldbedecodedbeforetheappearanceofthespatialcue,
which indicates that abstract rule information is present in PRR that is independent of spatial cue or motor goal representations. Our
findings support the hypothesis that PRR immediately translates current sensory information into reach movement plans, rather than
storing the memorized cue location in the instructed-delay task. This finding indicates that PRR represents integrated knowledge on
spatial sensory information combined with abstract behavioral rules to encode the desired movement goal.
Key words: sensorimotor transformation; posterior parietal cortex; motor intention; goal-directed behavior; anti-reach; S­R

  

Source: Andersen, Richard - Division of Biology, California Institute of Technology

 

Collections: Biology and Medicine