EEG characterization using acoustic stimuli from chaotic system circuits

Abstract

Dynamical systems theory has given way to the development of theoretical models, mathematical tools and experimental techniques in current neuroscience research. As such, neuroscience has come to strongly rely on the use of these nonlinear dynamics to better understand the characteristics of these processes, specially through the properties from its most notorious feature of which is chaos. A very interesting feature of chaos is that it basically involves variations over time, and it does so in a very specific way that is unpredictable, aperiodic, but deterministic. As such, these variations create oscillations that lead to the formation of waves with defined amplitude and frequency. Taking into the account this fact, the main objective of this investigation was to record acoustic signals derived from the voltage of chaotic systems implemented using electronic circuits and utilize them as auditory stimuli to analyze brain effects using perception evaluations and power spectral features on EEG signals. In this investigation we acquired acoustic signals from one aleatory and four deterministic processes. Among this, three of them constituted signals derived from strange attractors and one from a limit cycle behavior. The aim was to study the different effects that these random and deterministic processes could provoke in the human brain, specially those derived from chaotic dynamics. The present work confirmed that the three auditory stimulation processes derived from chaotic systems presented stronger relative and statistical differences from basal state compared to the aleatory and periodic stimulations. Specifically, up to negative (30 and 40) % relative differences in delta and theta power were found in specific EEG locations, mainly frontal regions of the brain, using these chaotic stimulations.