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Behavioral/Systems/Cognitive Gain Mechanisms for Contextually Guided

Summary: Behavioral/Systems/Cognitive
Gain Mechanisms for Contextually Guided
Visuomotor Transformations
Marina Brozovic´,1* Alexander Gail,1,2* and Richard A. Andersen1
1Division of Biology, California Institute of Technology, Pasadena, California 91125, and 2Bernstein Center for Computational Neuroscience, German
Primate Center, 37077 Go¨ttingen, Germany
results in decisions about motor actions. We used neural network models to study how context-specific visuomotor remapping may
depend on the functional connectivity among multiple layers. Networks were trained to perform different rotational visuomotor associ-
network (bottom-up), whereas in network II, it was propagated backwards (top-down). During the presentation of the visual cue stim-
ulus, both networks integrate the context with the sensory information via a mechanism similar to the classic gain field. The recurrence
in the networks hidden layers allowed a simulation of the multimodal integration over time. Network I learned to perform the proper
visuomotor transformations based on a context-modulated memory of the visual cue in its hidden layer activity. In network II, a brief
visual response, which was driven by the sensory input, is quickly replaced by a context-modulated motor-goal representation in the
after the disappearance of the visual cue, conveys motor goal information. We also show that the origin of the context information is not
parietal cortex during context-specific movement planning might be the consequence of strong top-down feedback originating from
within the parietal lobe or from the frontal lobe.


Source: Andersen, Richard - Division of Biology, California Institute of Technology
Crawford, Doug - York Centre for Vision Research, York University (Toronto)


Collections: Biology and Medicine