Remapping Peripersonal Space by Using Foot-Sole Vibrations Without Any Body Movement

Area of Science:

• Neuroscience
• Cognitive Science
• Sensory Processing

Background:

• Peripersonal space (PPS) is the space immediately surrounding the body.
• PPS is known to change with multisensory stimuli and body actions like walking.
• It remains unclear if PPS representation changes with simulated walking sensations without actual body movement.

Purpose of the Study:

• To investigate if a walking-like sensation, induced by auditory-tactile stimuli on the feet, can alter peripersonal space representation.
• To determine if stimulating the soles of the feet can extend PPS without requiring body movement.

Main Methods:

• Participants received rhythmic walking-sound vibrations applied to the soles of their feet or forearms.
• Tactile processing was assessed using audio-tactile stimuli presented within or outside the peripersonal space.
• The effect of looming sounds on tactile processing was measured.

Main Results:

• Rhythmic vibrations on the soles of the feet, mimicking walking, enhanced tactile processing when looming sounds were near the body.
• Vibrations applied to the forearms did not produce the same enhancement.
• This effect occurred without any actual body movement or forced motion.

Conclusions:

• Simulated walking sensations, specifically through sole stimulation, can extend peripersonal space representation.
• This extension may be driven by an automatic motor program for walking triggered by the sensory input.
• Findings suggest that spatial cognition around the body can be altered by sensory experiences without overt motor action.