Implications of shared motor and perceptual activations on the sensorimotor cortex for neuroprosthetic decoding

Area of Science:

• Neuroscience
• Biomedical Engineering
• Speech Science

Background:

• Neuroprostheses aim to restore communication for individuals with paralysis by decoding speech intentions from the sensorimotor cortex (SMC).
• The SMC is involved in both motor and perceptual functions, raising questions about potential interference with speech decoding during daily activities like reading and listening.

Purpose of the Study:

• To develop and evaluate an electrocorticography (ECoG)-based speech-decoding system for neuroprostheses.
• To assess the system's accuracy and specificity during concurrent speech, reading, and listening tasks.
• To investigate the neural representations of speech, reading, and listening in the SMC.

Main Methods:

• Developed an online ECoG-based speech-decoding system for two participants with vocal-tract paralysis.
• Tested the system's performance during attempted speech and perceptual tasks (reading, listening).
• Conducted offline analysis of spectrotemporal characteristics and spatial distribution of neural responses.

Main Results:

• The speech-decoding system maintained accuracy and specificity to intended speech during daily tasks.
• Zero false-positive activations were observed during 63.2 minutes of attempted speech and perceptual tasks.
• Shared neural populations in the middle precentral gyrus responded to speech, listening, and reading, but with differentiable spectrotemporal responses.

Conclusions:

• The developed decoding framework demonstrates a reliable speech neuroprosthesis that retains specificity to volitional speech attempts during daily activities.
• This research advances the understanding of shared perceptual and motor activity within the SMC.
• The findings support the development of practical neuroprosthetic communication systems for individuals with anarthria.