Neuronal correlates of full and partial visual conscious perception.

Partial consciousness—where the presence but not identity of an object can be reported—and full consciousness have distinct neural signatures. Recording brain activity with magnetoencephalography during a visual task, partial consciousness was linked to an early increase in evoked activity and theta/low-alpha-band oscillations. Full consciousness additionally involved late evoked activity and beta-band oscillations. Stronger evoked activity and a late increase in theta oscillations in higher-order visual regions, posterior parietal, and prefrontal cortices dissociated full from partial consciousness. The findings indicate that both evoked activity and theta oscillations differentiate these levels of conscious perception.

Study at a glance

Abstract

Stimuli may induce only partial consciousness-an intermediate between null and full consciousness-where the presence but not identity of an object can be reported. The differences in the neuronal basis of full and partial consciousness are poorly understood. We investigated if evoked and oscillatory activity could dissociate full from partial conscious perception. We recorded human cortical activity with magnetoencephalography (MEG) during a visual perception task in which stimulus could be either partially or fully perceived. Partial consciousness was associated with an early increase in evoked activity and theta/low-alpha-band oscillations while full consciousness was also associated with late evoked activity and beta-band oscillations. Full from partial consciousness was dissociated by stronger evoked activity and late increase in theta oscillations that were localized to higher-order visual regions and posterior parietal and prefrontal cortices. Our results reveal both evoked activity and theta oscillations dissociate partial and full consciousness.