Prestimulus oscillatory power and connectivity patterns predispose conscious somatosensory perception.

Area of Science:

• Neuroscience
• Cognitive Science

Background:

• Conscious perception depends on both stimulus features and brain state.
• Previous studies link reduced alpha-power (8-12 Hz) in sensory areas to conscious awareness of near-threshold stimuli.
• Existing interpretations focus on local cortical excitability.

Purpose of the Study:

• To propose a framework where prestimulus functional connectivity architecture, not just local excitability, predicts conscious perception.
• To investigate how network-level information flow influences conscious access.

Main Methods:

• Reanalysis of existing magnetoencephalography/EEG data from a somatosensory perception experiment.
• Focus on the prestimulus period to analyze spectral power and graph theoretical network features.
• Comparison of brain states preceding perceived (hits) versus unperceived (misses) stimuli.

Main Results:

• Reduced prestimulus alpha-power in contralateral S2 and middle frontal gyrus was observed for perceived stimuli, supporting prior findings.
• Significant differences in global network features were found between hits and misses in the prestimulus interval.
• The somatosensory cortex showed more efficient integration into a distributed network before stimulus onset for perceived events.

Conclusions:

• Prestimulus functional connectivity patterns, specifically network integration, are crucial for conscious perception.
• Efficient network integration facilitates information flow, making sensory data consciously accessible.
• These network dynamics create "windows" for conscious awareness, complementing local neural activity explanations.