Subcortical arousal systems help control sustained changes in attention and conscious awareness, and recent studies suggest they also influence short-term dynamic modulation of visual attention, but their role across sensory modalities is unclear. Analyzing fMRI data from 1561 participants performing visual, auditory, tactile, and taste perception tasks, a shared circuit of subcortical arousal systems was identified. This circuit shows early transient increases in activity in the midbrain reticular formation and central thalamus across all sensory modalities, with less consistent increases in the pons, hypothalamus, basal forebrain, and basal ganglia. Identifying these networks is critical for understanding normal attention and consciousness and may aid subcortical targeting for therapeutic neuromodulation.
An open science adversarial collaboration directly juxtaposed Integrated Information Theory (IIT) and Global Neuronal Workspace Theory (GNWT) by investigating neural correlates of visual experience. 256 human subjects viewed suprathreshold stimuli for variable durations while neural activity was measured with fMRI, MEG, and ECoG. Information about conscious content was found in visual, ventro-temporal, and inferior frontal cortex, with sustained responses in occipital and lateral temporal cortex reflecting stimulus duration, and content-specific synchronization between frontal and early visual areas.