Extending peripersonal space representation without tool-use: evidence from a combined behavioral-computational...

Area of Science:

• Neuroscience
• Computational Neuroscience
• Human Perception

Background:

• The peripersonal space (PPS) is a multisensory representation of space near the body.
• PPS dynamically adapts with experience, notably extending when using tools.
• The neural mechanisms behind PPS plasticity, especially after tool use, remain unclear.

Purpose of the Study:

• To propose and computationally test a neural mechanism for peripersonal space extension after tool use.
• To investigate the role of synchronous sensory input in PPS plasticity.
• To validate computational findings with behavioral experiments.

Main Methods:

• Developed a neural network model simulating audio-tactile interactions in PPS.
• Simulated tool use by pairing simulated tactile hand stimulation with auditory far-space stimulation.
• Conducted behavioral experiments using an audio-tactile paradigm to measure PPS boundaries in humans.

Main Results:

• The neural network model successfully replicated PPS neuron properties and predicted PPS extension.
• Simulated tool use (synchronous tactile-auditory input) led to PPS extension in the model.
• Behavioral experiments confirmed that synchronous audio-tactile stimulation extends PPS in healthy volunteers.

Conclusions:

• Synchronous pairing of tactile hand and auditory far-space stimuli is sufficient to extend PPS.
• This provides a biologically plausible model for PPS plasticity following tool use.
• Asynchronous sensory input does not induce PPS extension, highlighting the importance of temporal synchrony.