ECHOES: Extracting the Human Motor Null Space from Muscles. A new framework to measure human neural activity

By contracting our muscles, we move and interact with the world. In turn, the activated muscles act as signal repeaters of the neural inputs they receive. Muscles do not only receive inputs determining how they need to contract (and thereby how we move), but they also receive a rich set of neural information originating in the central nervous system and travelling through nerves and muscles without directly altering motor commands. This ‘motor null space’ in the muscles may represent a unique opportunity to explore the human central nervous system in an unobtrusive, spatially selective, and robust way, thereby overcoming the most critical inherent limitations of currently available non-invasive neuroimaging technologies. To test this novel concept, fundamental research is needed to develop methods to extract, separate, and interpret the non-motor neural projections to human muscles.

ECHOES will capitalize on recent breakthroughs in decoding the spinal outputs to muscles to develop a theoretical and experimental framework to unveil the ‘motor null space’ in human muscles. The project will then demonstrate the potential benefits of the extracted neural information in three scientific fields with growing societal and clinical impact: human-machine interfaces, targeted brain neuromodulation, and diagnosis of movement disorders.

We expect that the project’s multidisciplinary research program will further our understanding of the origin and relevance of neural signals generated by the human brain and spinal cord. This will markedly improve future research aimed to understand, use, and modulate human neural activity by providing a first-of-its-kind, minimally invasive and robust neuroimaging technology with unprecedented spatio- temporal resolution. By achieving these goals, ECHOES technology will enable the development of new applications for the clinical and industry fields.