Motor learning reveals the existence of multiple codes for movement planning

Todd E. Hudson, Michael S. Landy

Research output: Contribution to journalArticlepeer-review


Coordinate systems for movement planning are comprised of an anchor point (e.g., retinocentric coordinates) and a representation (encoding) of the desired movement. One of two representations is often assumed: a final-position code describing desired limb endpoint position and a vector code describing movement direction and extent. The existence of movement-planning systems using both representations is controversial. In our experiments, participants completed reaches grouped by target location (providing practice for a final-position code) and the same reaches grouped by movement vector (providing vector-code practice). Target-grouped reaches resulted in the isotropic (circular) distribution of errors predicted for position-coded reaches. The identical reaches grouped by vector resulted in error ellipses aligned with the reach direction, as predicted for vector-coded reaches. Manipulating only recent movement history to provide better learning for one or the other movement code, we provide definitive evidence that both movement representations are used in the identical task.

Original languageEnglish (US)
Pages (from-to)2708-2716
Number of pages9
JournalJournal of neurophysiology
Issue number10
StatePublished - Nov 15 2012


  • Coordinate systems
  • Internal representation
  • Motor noise
  • Motor planning
  • Planning error

ASJC Scopus subject areas

  • General Neuroscience
  • Physiology


Dive into the research topics of 'Motor learning reveals the existence of multiple codes for movement planning'. Together they form a unique fingerprint.

Cite this