Tactile exploration and imagery elicit distinct neural dynamics in the parietal cortical network

TL;DR

The study shows that tactile perception and imagery use similar brain areas but different neural communication patterns in the parietal cortex.

Contribution

The study reveals distinct neural dynamics in parietal cortical communication during tactile perception versus imagery.

Findings

Texture scanning inhibits neural synchronization while imagery activates it.

Communication from somatosensory cortex to PPC is suppressed during scanning but enhanced during imagery.

Bidirectional communication between supramarginal gyrus and precuneus occurs only during imagery.

Abstract

Tactile imagery involves the reconstruction of sensory experiences without actual tactile input. While tactile perception and imagery exhibit similar spatial patterns of neural activation, the underlying neural dynamics, particularly cortical communications within the parietal network, remain unclear.

The present study recruited 5 patients with implanted stereo-electroencephalography (sEEG) electrodes and recorded sEEG data during texture scanning and imagery. Local neural representations and interregional communications among parietal cortical regions were analyzed.

Opposing modulation patterns of local time-frequency representations were observed, with inhibited neural synchronization during texture scanning and activated synchronization during texture imagery. Consistently, the directional communication from the somatosensory cortex to the posterior parietal cortex (PPC) was found to be suppressed for scanning but enhanced for imagery. Additionally, bidirectional communication between the supramarginal gyrus and precuneus was activated during imagery but not scanning, suggesting a unique pathway for reconstructing tactile experiences.

Our findings proposed that while texture perception and imagery engage overlapping cortical regions, their mechanisms underlying local encoding and interregional communication are distinct.

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