Emergence of a Stable Cortical Map for Neuroprosthetic Control

• Published in: PLoS biology Vol. 7; no. 7; p. e1000153
• Main Authors: Ganguly, Karunesh, Carmena, Jose M.
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 21.07.2009; Public Library of Science (PLoS)
• Subjects: Analysis; Animals; Brain; Brain Mapping; Brain research; Control; Cortical maps; Emergence (Systems theory); Evoked Potentials, Motor - physiology; Experiments; Macaca; Mechanical properties; Mental Recall - physiology; Monkeys & apes; Motor Activity - physiology; Motor Cortex - cytology; Motor Cortex - physiology; Motor Neurons - physiology; Motor Skills - physiology; Neural prostheses; Neuronal Plasticity - physiology; Neurons; Neuroscience/Behavioral Neuroscience; Neuroscience/Cognitive Neuroscience; Neuroscience/Motor Systems; Prostheses and Implants; Time Factors; User-Computer Interface; United States; User-Computer Interface; Mental Recall; Prostheses & Implants; Motor Activity; Evoked Potentials, Motor; Animals; Motor Cortex; Time Factors; Neuronal Plasticity; Brain Mapping; Motor Neurons; Macaca; Motor Skills
• ISSN: 1545-7885; 1544-9173; 1545-7885
• DOI: 10.1371/journal.pbio.1000153

Cortical control of neuroprosthetic devices is known to require neuronal adaptations. It remains unclear whether a stable cortical representation for prosthetic function can be stored and recalled in a manner that mimics our natural recall of motor skills. Especially in light of the mixed evidence for a stationary neuron-behavior relationship in cortical motor areas, understanding this relationship during long-term neuroprosthetic control can elucidate principles of neural plasticity as well as improve prosthetic function. Here, we paired stable recordings from ensembles of primary motor cortex neurons in macaque monkeys with a constant decoder that transforms neural activity to prosthetic movements. Proficient control was closely linked to the emergence of a surprisingly stable pattern of ensemble activity, indicating that the motor cortex can consolidate a neural representation for prosthetic control in the presence of a constant decoder. The importance of such a cortical map was evident in that small perturbations to either the size of the neural ensemble or to the decoder could reversibly disrupt function. Moreover, once a cortical map became consolidated, a second map could be learned and stored. Thus, long-term use of a neuroprosthetic device is associated with the formation of a cortical map for prosthetic function that is stable across time, readily recalled, resistant to interference, and resembles a putative memory engram.