Unraveling the Neural Network: Identifying Temporal Labeling of Visual Events through EEG-Based Functional Connectivity Analysis of Brain Regions

Understanding the complex interplay between the brain and a dynamic environment necessitates the continuous generation and updating of expectations for forthcoming events and their corresponding sensory and motor responses. This study investigates the interconnectivity patterns associated with time perception in predictable and unpredictable conditions. EEG signals were obtained from an existing database, encompassing an experiment conducted on healthy participants subjected to two conditions: predictable and unpredictable, across various time delays. Functional connectivity between brain regions was estimated using the phase lag index method, allowing for the identification of differences in time perception between conditions. Comparative analysis revealed significant variations, particularly in the gamma, beta, and theta frequency bands, with more pronounced differences observed in the predictable condition. Subsequent exploration of the dissimilarities within each delay demonstrated significant differences across all delays. Notably, the unpredictable condition exhibited increased connectivity within the alpha band during the 400-ms delay, specifically between occipital and temporal regions, with higher mean connectivity compared to the predictable condition. In the delta band, distinct connectivity patterns emerged, involving connections between central and frontal regions across different delays. Notably, heightened connectivity between central and prefrontal regions was observed during the 83-ms delay. The right hemisphere of the prefrontal cortex played a pivotal role in time perception. Furthermore, a decline in connectivity across the delta, theta, and beta bands was observed during the longest delay (800 ms) in both conditions, relative to other delays. These findings enhance our understanding of the neural mechanisms underlying time perception and underscore the impact of predictability on connectivity dynamics.

Sina Khoonbani, Hasan Ramezanian