title: Primary motor cortex and fast feedback responses to mechanical perturbations: a primer on what we know now and some suggestions on what we should find out next.
abstract: Many researchers have drawn a clear distinction between fast feedback responses to mechanical perturbations (e.g., stretch responses) and voluntary control processes. But this simple distinction is difficult to reconcile with growing evidence that long-latency stretch responses share most of the defining capabilities of voluntary control. My general view-and I believe a growing consensus-is that the functional similarities between long-latency stretch responses and voluntary control processes can be readily understood based on their shared neural circuitry, especially a transcortical pathway through primary motor cortex. Here I provide a very brief and selective account of the human and monkey studies linking a transcortical pathway through primary motor cortex to the generation and functional sophistication of the long-latency stretch response. I then lay out some of the notable issues that are ready to be answered.
authors.affiliation: Department of Integrative Medical Biology, Physiology Section, Umeå University Umeå, Sweden.
authors.forename: J Andrew
authors.initials: JA
authors.lastname: Pruszynski
keywords: long-latency; primary motor cortex; reflex; transcortical pathway; upper-limb