Distinct patterns of whole-body coding in human motor cortex and posterior parietal cortex.

Hand area of human motor cortex (MC) shows more selective responses to hand movements, while posterior parietal cortex (PPC) strongly represents all effectors, indicating distinct coding patterns.

• Why it matters: Understanding how different cortical areas encode movements is crucial for insights into motor control and neuroprosthetic development, especially given the debate over effector overlap in these regions.
• What they did: Single-neuron recordings from hand regions of MC and PPC in tetraplegic humans during attempted movements revealed that MC neurons are effector-specific, while PPC neurons exhibit mixed selectivity across multiple effectors.
• The result: Findings suggest a transition from effector-general representation in PPC to effector-specific coding in MC, which may inform models of motor planning and the design of brain-machine interfaces.