Human intralaminar and medial thalamic nuclei transiently gate conscious perception through the thalamocortical loop

Abstract Human high-order thalamic nuclei have been known to closely correlate with conscious states. However, given the great difference of conscious states and contents (conscious perception), it is nearly unknown how those thalamic nuclei and thalamocortical interactions directly contribute to the transient process of conscious perception. To address this question, we simultaneously recorded local field potentials (LFP) in the human intralaminar, medial and ventral thalamic nuclei as well as in the prefrontal cortex (PFC), while patients with implanted electrodes performing a visual consciousness task. Overall, compared to the ventral nuclei, intralaminar and medial nuclei showed earlier and stronger consciousness-related activity. Moreover, the transient thalamocortical neural synchrony and cross-frequency coupling were both driven by the theta phase of the intralaminar and medial nuclei during conscious perception. These results indicated that the intralaminar and medial thalamic nuclei, rather than the commonly believed PFC, play a decisive ‘gate’ role in conscious perception. Highlights Intralaminar and medial thalamic nuclei showed earlier and stronger visual consciousness-related activity, comparing to the ventral nuclei. Intralaminar and medial thalamic transiently drove the thalamocortical synchronization through theta (2-8Hz) phase modulation during the emergence of visual consciousness. Theta phase of intralaminar and medial thalamic activity dynamically regulated the amplitude of PFC activity during the emergence of consciousness. Intralaminar and medial thalamic nuclei showed more regulation on lateral PFC than on other PFC subregions during the emergence of consciousness.