Intrinsic functional architecture predicts electrically evoked responses in the human brain

Area of Science:

• Neuroscience
• Cognitive Science
• Brain Imaging

Background:

• Adaptive brain function relies on dynamic neuronal interactions at millisecond timescales.
• Resting-state functional MRI (R-fMRI) reveals intrinsic functional architecture via low-frequency fluctuations (<0.1 Hz).
• This architecture correlates with task-evoked activity and anatomical connectivity but its role in faster processes is unclear.

Purpose of the Study:

• To investigate if R-fMRI-identified intrinsic functional architecture scaffolds faster brain processes.
• To determine if resting-state network properties predict rapid electrophysiological responses.

Main Methods:

• Used R-fMRI to map intrinsic functional architecture.
• Administered single-pulse electrical stimulation to the cerebral cortex.
• Recorded corticocortical evoked potentials within 500 ms using intracranial electrodes.

Main Results:

• The spatial distribution and magnitude of R-fMRI low-frequency fluctuations predicted the pattern and magnitude of evoked potentials.
• This predictive relationship was consistent across different brain regions and functional systems.
• Findings were independent of the specific regions and functional systems probed.

Conclusions:

• R-fMRI low-frequency fluctuations provide a scaffold for faster neural processes, including information processing and seizure spread.
• This study bridges the temporal resolution gap between R-fMRI and electrophysiological measures.
• Low-frequency R-fMRI signals actively maintain and update the brain's intrinsic functional architecture.