[Functional exploration of the brain by fMRI]

Area of Science:

• Neuroimaging
• Biophysics
• Signal Processing

Context:

• Functional magnetic resonance imaging (fMRI) provides physiological insights into MRI signals.
• Brain interactions can be characterized by analyzing fMRI signals.
• Spectral analysis of fMRI signals offers insights into temporal dynamics of brain activity.

Purpose:

• To characterize brain interactions using fMRI signals.
• To employ spectral analysis for understanding time series chronology in activated brain areas.
• To develop a method for evaluating interaction intensity between distinct cerebral areas.

Summary:

• Spectral analysis, specifically coherency and phase shift, can be calculated from fMRI signals assuming stationary stochastic processes.
• Coherency quantifies frequency-domain correlation, enabling precise estimation of phase relations (time delays) between signals.
• A novel calculation method integrates spectral information to quantify the interaction intensity between two distinct brain regions.

Impact:

• Enables more accurate characterization of functional connectivity in the brain.
• Provides a quantitative measure of interaction intensity between brain areas.
• Advances the understanding of neural communication and network dynamics.