Summary
Objectives: This study aims to characterize EEG complexity, measured as the prediction error
resulting from nonlinear prediction, in healthy humans during photic stimulation.
Methods: EEGs were recorded from 15 subjects with eyes closed (EC) and eyes open (EO), during
the baseline condition and during stroboscopic photic stimulation (PS) at 5, 10, and
15 Hz. The mean squared prediction error (MSPE) resulting from nearest neighbor local
linear prediction was taken as complexity index. Complexity maps were generated interpolating
the MSPE index over a schematic scalp representation.
Results: Statistical analysis revealed that: i) EEG shows good predictability in all conditions
and seems to be well explained by a linear stochastic process; ii) the complexity
is lower with EC than with EO and increases significantly during PS, to a lesser extent
during 10 Hz stimulation; iii) significant differences of EEG complexity are detectable
between anterior-central and posterior scalp regions.
Conclusions: Changes in EEG complexity during PS can be successfully assessed using nonlinear
prediction. The observed modifications in the patterns of complexity seem to reflect
neurophysiological behaviors and suggest future applicability of the method in clinical
settings.
Keywords
EEG - local linear prediction - predictability maps - visual stimulation