Disrupting posterior cingulate connectivity disconnects consciousness from the external environment

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Neurology

Background:

• Neuroimaging studies implicate the medial posteroparietal cortex (PPC) in conscious information processing.
• Direct neuropsychological evidence and studies on lesions in this region are scarce.

Observation:

• Direct intraoperative electrostimulations were used in a rare patient.
• Disrupting the subcortical connectivity of the left posterior cingulate cortex (PCC) was performed.

Findings:

• Disruption reliably induced a breakdown in conscious experience, characterized by transient unresponsiveness and loss of external connectedness.
• Upon regaining consciousness, the patient reported dream-like experiences outside the operating room.

Implications:

• Functional integrity of the PPC connectivity is necessary for maintaining consciousness of the external environment.
• This provides crucial neuropsychological evidence supporting the PPC's role in consciousness.