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The posterior parietal cortex encodes in parallel both goals for double-reach sequences
Daniel Baldauf1, He Cui, Richard A Andersen
1Division of Biology, California Institute of Technology, Pasadena, California 91125, USA. daniel@vis.caltech.edu
Summary
The parietal reach region (PRR) encodes both immediate and subsequent movement goals during planned double-reach sequences. This suggests the posterior parietal cortex supports complex action planning beyond single targets.
Area of Science:
- Neuroscience
- Cognitive Neuroscience
- Primate Motor Control
Background:
- The parietal reach region (PRR) is recognized for its role in preparing visually guided arm movements toward single targets.
- Previous research has not fully elucidated whether PRR exclusively encodes the immediate target or also anticipates future goals in sequential movements.
Purpose of the Study:
- To investigate whether the PRR encodes only the immediate target or also a subsequent goal within a double-reach sequence.
- To explore the neural mechanisms underlying the planning of complex, sequential arm movements.
Main Methods:
- Two monkeys were trained on a memory-guided delayed double-reach task involving memorizing two peripheral cue locations.
- Neural activity of single cells in the PRR was analyzed during the memory period preceding movement execution.
- The experimental design ensured that either the first or second movement target fell within the recorded neuron's response field.
Main Results:
- During the memory period, the majority of PRR cells demonstrated encoding of both the first and second goals in the planned reaching sequence.
- This neural activity occurred prior to the GO-signal, indicating proactive planning.
Conclusions:
- The findings suggest that the posterior parietal cortex is involved in the spatial planning of more intricate action patterns.
- PRR neurons represent both immediate and subsequent movement goals, contributing to the execution of sequential behaviors.
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