Activation in the ipsilateral posterior parietal cortex during tool use: a PET study.

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Human Motor Control

Background:

• Tool use is a hallmark of human cognition.
• Understanding how the brain integrates sensory information for tool use is crucial for understanding body schema modification.
• Previous research suggests multimodal sensory integration is key for body schema adaptation.

Purpose of the Study:

• To identify brain regions involved in the perceptual assimilation of tools and hands.
• To investigate changes in neural activity during tool manipulation compared to finger manipulation.
• To explore the role of the posterior parietal cortex in integrating visual and somatosensory information during tool use.

Main Methods:

• Positron emission tomography (PET) with H(2)(15)O was used to measure brain activity.
• Participants performed object manipulation tasks using either tongs (tool) or fingers.
• Tasks were performed with the right and left hands, with a control task for baseline comparison.

Main Results:

• Tool use with the right hand specifically activated the lateral edge of the right intraparietal sulcus (IPS).
• Tool use with the left hand activated a middle area of the left IPS.
• No significant difference in contralateral hemisphere activation was found between tool and finger use compared to a control task.

Conclusions:

• The ipsilateral posterior parietal cortex is recruited during tool-use tasks.
• This recruitment supports the integration of visuosomatosensory information for tool assimilation.
• Findings suggest a role for the posterior parietal cortex in adapting the body schema for tool interaction.