Synchronization of Cortical EEG Signal During Natural Movie Viewing

In this study we used movies to modulate different level of engagement. Engagement was defined as “emotionally laden attention” similar to the seminal study of Dmochowski and colleagues (2012). We measured neural underpinnings of engagement as a similarity of cortical signals between subjects during movie viewing using correlated components analysis (CCA). Resulting inter-subject correlations (ISC) can be interpreted as an audiences’ level of engagement. The main idea of this analysis is to find components in electroencephalogram (EEG) signal which are maximally correlated between several data sets. Our results agreed with previous studies. We found a difference of ISC for videos with low and high engagement. We also demonstrated usefulness of the ISC approach in studies of the contextual effects on sensory processing of complex scenes. Importantly, we uncover that abrupt scene changes can affect ISC values.