Figure 1.

Research concept and approach. A, LC-NA and BF-ACh systems with widespread neuromodulatory effects on neuronal population activity as measured with MEG. Pupil size reflects activity of both systems. B, MEG data were source reconstructed and subjected to spectral analysis. Neuronal power envelopes and the dynamic of cortical phase and amplitude coupling were each temporally cross-correlated with pupil dynamics. Insets show power spectra of pupil size time sources and of power envelopes in different frequency bands averaged across all subjects and cortical space. C, 3D cluster permutation statistics were used to identify coupling between neuronal and pupil dynamics across cortical space, frequency, and relative time lag between pupil and the neuronal dynamics.