Common dynamic properties of biosignals during cognition: self-similarity and chaotic dynamics of both response times and EEG during movement imagery

This study was undertaken to verify whether different output variables or biosignals, measured during performance of a cognitive task, manifest common dynamical properties. Nonlinear properties of both response times (RTs) and electroercephalograms (EEG) were tested. We asked subjects to generate mental images of actions following of auditorily presentation simple phrases suggesting the action. Analysis of RT series combined from many subjects and of EEG records from single subjects clearly manifested self-similarity and chaotic dynamics that provide insights into the self-organization of the brain/behavioral system.