Microstimulation of macaque area LIP affects decision-making in a motion discrimination task

Nat Neurosci. 2006 May;9(5):682-9. doi: 10.1038/nn1683. Epub 2006 Apr 9.


A central goal of cognitive neuroscience is to elucidate the neural mechanisms underlying decision-making. Recent physiological studies suggest that neurons in association areas may be involved in this process. To test this, we measured the effects of electrical microstimulation in the lateral intraparietal area (LIP) while monkeys performed a reaction-time motion discrimination task with a saccadic response. In each experiment, we identified a cluster of LIP cells with overlapping response fields (RFs) and sustained activity during memory-guided saccades. Microstimulation of this cluster caused an increase in the proportion of choices toward the RF of the stimulated neurons. Choices toward the stimulated RF were faster with microstimulation, while choices in the opposite direction were slower. Microstimulation never directly evoked saccades, nor did it change reaction times in a simple saccade task. These results demonstrate that the discharge of LIP neurons is causally related to decision formation in the discrimination task.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Action Potentials / physiology
  • Action Potentials / radiation effects
  • Animals
  • Behavior, Animal
  • Decision Making / physiology*
  • Decision Making / radiation effects
  • Discrimination, Psychological / physiology*
  • Discrimination, Psychological / radiation effects
  • Electric Stimulation / methods
  • Macaca mulatta
  • Motion Perception / drug effects
  • Motion Perception / physiology*
  • Neurons / physiology*
  • Neurons / radiation effects
  • Parietal Lobe / cytology*
  • Photic Stimulation / methods
  • Reaction Time / physiology
  • Reaction Time / radiation effects
  • Saccades / physiology