Effects of Repetitive SSVEPs on EEG Complexity using Multiscale Inherent Fuzzy Entropy

TL;DR

This study demonstrates that EEG complexity, measured by multiscale inherent fuzzy entropy, increases with repetitive SSVEP stimuli, indicating brain habituation, and shows this method's superiority over other entropy measures.

Contribution

It introduces multiscale inherent fuzzy entropy as a superior method for assessing EEG complexity during repetitive SSVEP stimuli, revealing habituation effects.

Findings

EEG complexity increases with stimulus repetitions.

Occipital EEG complexity is higher at the fifth SSVEP than the first.

Multiscale inherent fuzzy entropy outperforms other entropy methods.

Abstract

Multiscale inherent fuzzy entropy is an objective measurement of electroencephalography (EEG) complexity, reflecting the habituation of brain systems. Entropy dynamics are generally believed to reflect the ability of the brain to adapt to a visual stimulus environment. In this study, we explored repetitive steady-state visual evoked potential (SSVEP)-based EEG complexity by assessing multiscale inherent fuzzy entropy with relative measurements. We used a wearable EEG device with Oz and Fpz electrodes to collect EEG signals from 40 participants under the following three conditions: a resting state (closed-eyes (CE) and open- eyes (OE) stimulation with five 15-Hz CE SSVEPs and stimulation with five 20-Hz OE SSVEPs. We noted monotonic enhancement of occipital EEG relative complexity with increasing stimulus times in CE and OE conditions. The occipital EEG relative complexity was significantly higher for the fifth SSVEP than for the first SSEVP (FDR-adjusted p < 0.05). Similarly, the prefrontal EEG relative complexity tended to be significantly higher in the OE condition compared to that in the CE condition (FDR-adjusted p < 0.05). The results also indicate that multiscale inherent fuzzy entropy is superior to other competing multiscale-based entropy methods. In conclusion, EEG relative complexity increases with stimulus times, a finding that reflects the strong habituation of brain systems. These results suggest that multiscale inherent fuzzy entropy is an EEG pattern with which brain complexity can be assessed using repetitive SSVEP stimuli.