Limb position drift results from misalignment of proprioceptive and visual maps

Area of Science:

• Neuroscience
• Human Motor Control
• Perception

Background:

• Repetitive limb movements without visual feedback cause position drift.
• This drift may indicate a visual-proprioceptive map misalignment.

Purpose of the Study:

• To investigate if limb position drift reflects visual and proprioceptive map misalignment.
• To examine the information used for specifying new movements from a drifted limb position.

Main Methods:

• Participants performed repetitive hand movements in a virtual reality (VR) environment.
• Visual feedback was removed to induce limb position drift.
• Kinematic and forward dynamics analyses were used to assess movement control.

Main Results:

• Movement direction was guided by visual cues (start/last-seen hand position).
• Accurate proprioceptive information of the drifted limb was used for new movement planning.
• Movement distance correlated with the extent of limb drift.

Conclusions:

• Limb drift during cyclic movements without vision suggests a misalignment between visual and proprioceptive maps.
• This misalignment, rather than weighted sensory fusion, likely explains the observed drift.