Motor Organization

Overview

This set of studies has focused on revealing features of the static and dynamic organization of movement, mostly in neocortical structures, but has also included some behavioral studies.  An early inspiration of this work was our findings that the arm representation of monkey primary motor cortex (M1) had a 'mosiac' like organization for muscles and movements of the upper limb.  Specifically, using intracortical stimulation methods, we found multiple, overlapping representations for distal and proximal parts of the upper limb (Donoghue et al. Experimental Brain Research 89:1-19; 1992).  That is, M1 regions related to finger movements, also could be related to more proximal actions, such as wrist, elbow or shoulder movements.  The converse was also true, M1 sites best related to proximal movements, such as the shoulder, often also had more distal movement representations.  Another inspiration for this work concerned a series of studies done with John Donoghue in which we discovered that rodent motor cortex exhibited representation plasticity (e.g., Sanes et al. Cerebral Cortex 2:141-152).  Combined these studies suggested that the static organization of M1 had a latent propensity to exhibit dynamic functional properties, a potential substrate for motor learning.

Key findings using neuroimaging have included:

  • Mosaic functional representions for arm movement in neocortical areas
  • Dynamic representations for movement rate and movement number in neocortex
  • Evidence for movement direction tuning in human motor cortical areas

Publications  (If you download PDF versions of the publications, you have tacitly agreed to Fair Use policies.)

  • Bédard P, Churchill T, Sanes JN (2011)  Gaze effects on directional coding of reaching in human frontal and parietal cortex.  17th International Conference on Functional Mapping of the Human Brain, June 2011.
  • Thaut, M, M. Demartin, and J. N. Sanes (2008) Brain networks for integrative rhythm formation. PLoS ONE, 3: e2312.  Pubmed citation | Download PDF
  • Philip B. A., Y. Wu, J. P. Donoghue, J. N. Sanes  (2008)  Computational predictions of performance differences in visually- and internally-guided continuous manual tracking movements.  Experimental Brain Research 190:475-491.  Pubmed citation | Download PDF
  • Kim J. A., J. C. Eliassen, and J. N. Sanes (2005) Movement quantity and frequency coding in human motor areas. Journal of Neurophysiology 94:2504-2511.  Pubmed citation | Download PDF
  • Sanes J. N. and M. H. Schieber (2001)  Orderly somatotopy in primary motor cortex: Does it exist?  NeuroImage, 13: 968-974.   Pubmed citation | Download pdf
  • Indovina I. and J. N. Sanes (2001) On somatotopic representation centers for finger movements in human primary motor cortex and supplementary motor area. NeuroImage, 13: 1027-1034.
  • Bhat, R. B. and J. N. Sanes  (1998) Cognitive channels computing action distance and direction.  Journal of Neuroscience, 18:7566-7580.  Pubmed citation |  Download pdf
  • Marzi, C. A., C. Miniussi, A. Maravita, L. Bertolasi, G. Zanette, J. C. Rothwell and J. N. Sanes  (1998)  Transcranial magnetic stimulation selectively impairs interhemispheric transfer of visuo-motor information in humans. Experimental Brain Research, 118: 435-438.  Pubmed citation | Download pdf
  • Schlaug, G., J. N. Sanes, V. Thangaraj, D. G. Darby, L. Jäncke, R. R. Edelman, and S. Warach  (1996)  Cortical activation covaries with movement rate.  NeuroReport, 7:  879-883.  Pubmed citations
  • Sanes, J. N., J. P. Donoghue, V. Thangaraj, R. R. Edelman and S. Warach  (1995)  Shared neural substrates controlling hand movements in human motor cortex.  Science, 268: 1775-1777.  Pubmed citations | Download pdf