Expert Tool Users Show Increased Differentiation between Visual Representations of Hands and Tools.

Area of Science:

• Neuroscience
• Cognitive Science
• Human-Computer Interaction

Background:

• The concept of tool embodiment suggests tools become integrated into the body's neural representation.
• Direct neural evidence for tool embodiment remains limited.
• Understanding how the brain represents tools is crucial for various scientific and engineering fields.

Purpose of the Study:

• To investigate neural representations of tools in expert versus novice users.
• To test the theory of neural embodiment versus neural differentiation.
• To explore how extensive tool use shapes neural processing in the visual cortex.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to scan participants.
• Representational Similarity Analysis (RSA) measured differences in neural patterns.
• Participants viewed videos of hands and tools (litter pickers) during fMRI scans.

Main Results:

• Expert tool users (litter pickers) showed less neural similarity between their tool and their hand compared to novices.
• This neural differentiation effect was observed in the occipitotemporal cortex (OTC).
• Exploratory analysis in the left parietal cortex also supported increased neural differentiation in experts.

Conclusions:

• Extensive tool use leads to neural differentiation, not embodiment, of tools.
• Expertise with tools results in more distinct visual representations of hands and tools.
• Findings challenge the prominent tool embodiment theory and offer an alternative framework for understanding tool use and neural plasticity.