PAC

PAC quantifies phase-amplitude coupling by computing an Extended Modulation Index (eMI) with statistical significance estimation across phase and amplitude frequency pairs in comodulograms.

Key Features:

• Extended Modulation Index (eMI): Enhances the classical Modulation Index by incorporating statistical significance estimation for each pair of phase and amplitude frequencies across the entire comodulogram using extreme value statistics.
• Heuristic Algorithm: Classifies PAC signals as Reliable or Ambiguous based on analysis of spectral properties in relation to detected coupling, improving selectivity particularly in frequency dimensions associated with phase.
• Visualization Tools: Generates comodulogram visualizations and a polar phase-histogram for studying phase relations between slow and fast oscillations.
• Compatibility: eMI is applicable to both continuous and epoched data formats.

Scientific Applications:

• Validation and benchmarking: Tested on computer-simulated data and local field potential recordings from freely moving rats, demonstrating comparable sensitivity and specificity relative to the direct PAC estimator (a modification of Mean Vector Length) and the standard Modulation Index.

Methodology:

Computes an Extended Modulation Index with significance estimation using extreme value statistics for each phase–amplitude frequency pair across the comodulogram and applies a heuristic algorithm that classifies signals as Reliable or Ambiguous based on spectral-property analysis; outputs include comodulograms and a polar phase-histogram and the method accepts continuous and epoched data.