Social media activity is often used as a proxy for engagement with live media content. Together with our colleagues at Columbia University and City College of New York, we put this notion to the test. Using the premiere episode of the popular TV show The Walking Dead we designed a study to track and compare, in real time, the neural response of individual viewers, using electroencephalogram (EEG), with aggregated Twitter activity. We found that neural synchronicity is often significantly correlated with social media activity, although we discovered several instances — during emotional moments of distress and personal loss for the show’s protagonist — in which high neural engagement was not at all reflected in Twitter activity. This suggests a more complex relationship between engagement, character identification, and social media sharing, with implications for anyone using narrative media to disseminate ideas.