Using EEG To Enhance Measures of Engagement During an Informational Video.
Whether writing a blog, giving a presentation, or creating a video, you must engage your audience if you need to communicate information. It is easy to see if someone retained information simply by quizzing them afterward, but it is a bit more complicated if you want to know when people are engaged during the presentation or video. If you ask viewers during a video to indicate when they are engaged, they will disengage from the video and thereby compromise the results. You could ask them to reflect on what was engaging, but our memory for details is not very reliable. People tend to conflate “liking” and “engaging” as the same when they are not. Even so, they may only respond with one or two parts of the video and miss the other moments that engaged them. So, how can we measure engagement across groups of consumers?
Researchers in academia and industry rely on neuroscience to answer questions related to attention because the brain gives us less biased results compared to behavioral methods. Using electroencephalography (EEG) and doing a cross-brain-correlation (CBC) analysis, ThinkAlike Laboratories® measures engagement while consumers passively watch a video. Think Alike Laboratories founders, Dr. Sam Barnett and Dr. Moran Cerf found overall CBC for movie trailers predicted opening weekend ticket sales(1).
To apply CBC more broadly, we wanted to know if CBC could measure engagement when people watched an informative or educational video. Participants watched an airline safety video while researchers collected EEG data. After the video, participants were asked about their subjective engagement and whether they thought the video was informative. Our findings indicate that subjective ratings of informativeness and engagement were correlated (Figure 1).
We then divided the participants into two groups based on their informative ratings. Overall CBC was more significant in the group that thought the video was informative (high informative group) compared to the group that thought it was less informative (low informative group, Figure 2). These results suggest that, overall, CBC relates to engagement, however, the true benefit of CBC is the moment-to-moment analysis.
Figure 3 shows the CBC for each group (blue = high informative group and orange = low informative group) across the duration of the video. Screenshots of the video were added to show an example of the scene during the peaks and valleys. The peaks suggest that engagement in the video increases and the valleys suggest engagement decreases or people are engaging in different things. We see that the high informative group’s peaks were more significant than the low informative group. Additionally, the peaks in both groups were during informative scenes, and the valleys were during transition scenes (when the Star Wars images were present). The data indicates that people were engaged when visually simple scenes and information were being given, but engagement dropped during visually complex transition scenes.
The results of this study indicate the importance of a single attentional target (like a face) when communicating important information. Additionally, long, visually complex transition scenes may reduce engagement and make it more difficult to capture attention. Lastly, this research shows CBC’s usefulness extends beyond entertainment purposes (movie trailers and commercials) into educational media such as safety videos, lectures, and how-to-videos.
This data was presented at the 2022 Society for Neuroscience Conference.
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