Complexity of EEG Brain Signals Triggered by Fractal Visual Stimuli

Abstract

Fractality is observed in various repetitive structures within nature and humans, providing aesthetic beauty or specific functionalities. When viewing fractal structures, is there a fractal complexity connection between the brain activity and the fractal visual stimuli? In this paper we investigate the possible correlations between the complexity of both the synthetic fractal images and the response EEG signals during the fractal images visualization. We present the results using two complexity metrics: entropy and fractal dimension. While for images, the spatial and color domains are considered, for EEG signals, the time domain with its amplitude characteristics and power spectral density information are analyzed. Even though no significant linear correlations are observed between the complexity of perceived images and the complexity of brain responses, various non-linear trends emerge.