Primate premotor cortex: modulation of preparatory neuronal activity by gaze angle

Area of Science:

• Neuroscience
• Motor Control
• Primate Behavior

Background:

• The dorsal premotor cortex (PMd) is crucial for planning and executing limb movements.
• Understanding how sensory information, like eye position, influences motor planning is essential for comprehending neural control.

Purpose of the Study:

• To investigate the impact of varying eye positions on neuronal activity within the dorsal premotor cortex (PMd).
• To determine if eye position modulates neural representations of upcoming limb movements.

Main Methods:

• Two rhesus monkeys performed a conditional visuomotor task with a delayed response.
• Neuronal activity was recorded from the dorsal premotor cortex (PMd) while monkeys fixated targets and received directional cues.
• Eye position was manipulated across various screen locations, with head fixed, to analyze craniocentric modulations.

Main Results:

• For a majority of recorded dorsal premotor cortex (PMd) neurons (79%), activity during the delay period reflected the intended limb movement direction.
• This movement-related activity was significantly modulated by the monkey's eye position within the orbit.

Conclusions:

• Neuronal activity in the dorsal premotor cortex (PMd) related to motor planning is not solely based on movement intention but is also influenced by eye position.
• These findings highlight the integration of gaze information into motor control circuits for limb movements.