When pliers become fingers in the monkey motor system

Proc Natl Acad Sci U S A. 2008 Feb 12;105(6):2209-13. doi: 10.1073/pnas.0705985105. Epub 2008 Jan 31.

Abstract

The capacity to use tools is a fundamental evolutionary achievement. Its essence stands in the capacity to transfer a proximal goal (grasp a tool) to a distal goal (e.g., grasp food). Where and how does this goal transfer occur? Here, we show that, in monkeys trained to use tools, cortical motor neurons, active during hand grasping, also become active during grasping with pliers, as if the pliers were now the hand fingers. This motor embodiment occurs both for normal pliers and for "reverse pliers," an implement that requires finger opening, instead of their closing, to grasp an object. We conclude that the capacity to use tools is based on an inherently goal-centered functional organization of primate cortical motor areas.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Electromyography
  • Female
  • Macaca nemestrina
  • Male
  • Motor Cortex / cytology
  • Motor Cortex / physiology*
  • Neurons / physiology*