Does tool use extend peripersonal space? A review and re-analysis.

Area of Science:

• Cognitive Neuroscience
• Human-Computer Interaction
• Neuroscience

Background:

• The concept of tools as body extensions is explored in various disciplines.
• Hypotheses suggest tool use expands the neural representation of peripersonal space around the hands.
• Extensive research exists across molecular, neurophysiological, neuroimaging, neuropsychological, and behavioral fields.

Purpose of the Study:

• To review evidence for and against the hypothesis that tool use extends the neural representation of peripersonal space.
• To re-analyze data from seven experiments using the crossmodal congruency task to test this hypothesis.

Main Methods:

• Review of neurophysiological, neuropsychological, and behavioral evidence.
• Re-analysis of data from six published and one unpublished crossmodal congruency task experiments.

Main Results:

• The re-analysis broadly confirms that tool use does not literally extend peripersonal space.
• Observed effect sizes were small, and statistical power was low.
• Previous findings using the crossmodal congruency task are broadly supported.

Conclusions:

• Tool use does not appear to literally extend peripersonal space based on the analyzed data.
• The efficacy of the crossmodal congruency task in testing tool-induced peripersonal space modifications is questioned.
• Further investigation is required to understand the relationship between tool use and peripersonal space representation.