Example of a single trial analyses.

A) Z-normalized pupil size recorded for 30 seconds. B) Power spectrum and auto-correlogram spectrum of the z-normalized pupil data. C) Time frequency map showing the frequency power as a function of time: the power at each time step is color-coded; with red indicating a high power and blue a low power. The black line represents the maximum power frequency at each time step (black curve). The mean and variance of this maximum frequency distribution was used to characterize pupil dynamics.