Conscious tactile perception entails distinct neural dynamics within somatosensory areas.

Conscious perception of simple touch depends on sustained neural activity in higher-order somatosensory regions, specifically the posterior perisylvian areas. Using human intracortical recordings, tonic responses in these regions showed all-or-nothing patterns at the sensory threshold, remained unchanged whether or not participants reported the stimulus, and most clearly distinguished perceived from non-perceived stimuli. These dynamics may serve as an organizational principle of somatosensory awareness.

Study at a glance

Abstract

Distilling the neural correlates of consciousness (NCCs) in humans is challenging due to limitations in the spatiotemporal resolution of recording techniques and confounds related to pre- and post-perceptual processes. In this study, we leveraged the detailed insights provided by human intracortical recordings to elucidate how somatosensory responses to simple tactile stimuli vary across different stimulus intensities and reporting conditions. Among the various spatiotemporal components of somatosensory processing, we observed tonic responses in posterior perisylvian regions that exhibited all the key characteristics of somatosensory NCCs. These responses remained invariant regardless of reporting, displayed an all-or-nothing pattern at the verge of the sensory threshold, and showed the most pronounced divergence between perceived and non-perceived stimuli. Overall, our findings indicate that conscious perception of simple tactile stimuli depends on higher-order somatosensory regions and that sustained neural dynamics in these areas may serve as an organizational principle of somatosensory awareness.