Exploring Neural Synchronization with EEG Using Fractal Animations

This study explores inter-subject neural synchronization, measured via inter-subject correlation (ISC), using EEG during fractal animation observation. Fractal animations, characterized by iterative self-similarity and visual complexity, provide a controlled stimulus devoid of semantic or emotional content, facilitating analysis of core sensory and predictive mechanisms. Fifteen participants watched fractal animations while their EEG was recorded. Following preprocessing, including artifact removal and spatial filtering, ISC was calculated using correlated component analysis. Results showed robust synchronization in occipital regions, linked to early visual processing, and frontal areas, associated with attentional control. Two control manipulations—phase randomization and temporal shuffling—reduced ISC by 65% and 70% (p < 0.001), confirming coherence. Peak synchronization aligned with heightened visual complexity and abrupt transitions. A correlation between self-reported focus and ISC highlighted top-down modulation. These findings endorse fractal animations as a powerful paradigm for studying neural responses, yielding insights into multisensory integration and cognitive processing.