Movement enhances tactile sensitivity through prediction.

Area of Science:

• Neuroscience
• Sensory Perception
• Motor Control

Background:

• Tactile sensations often decrease in intensity during movement, a process called sensory gating.
• Existing theories offer different explanations for this somatosensory down-weighting during motion.

Purpose of the Study:

• To investigate how motor execution and prediction influence tactile sensations.
• To differentiate the effects of movement prediction from movement execution on tactile perception.

Main Methods:

• Precisely matched kinematics for active (self-generated) and passive (externally generated) movements.
• Compared perceived tactile intensity and sensitivity between active and passive conditions.
• Manipulated the predictability of passive movement velocity.

Main Results:

• Perceived tactile intensity was reduced in both active and passive movement conditions.
• Tactile sensitivity was enhanced during active movement compared to passive movement with matched kinematics.
• Predictable passive movement increased tactile sensitivity to the level of active movement.
• Temporal unpredictability impaired tactile precision but did not affect bias.

Conclusions:

• Movement does not globally suppress tactile processing; it differentially affects bias and precision.
• Predictions about upcoming movement kinematics sharpen tactile discrimination.
• A separate movement-related process reduces the perceived intensity of tactile sensations.