Portable EEG in groups shows increased brain coupling to strong health messages.

Health messages are core building blocks of public health efforts. Neuroscientific measures offer insights into how target audiences receive health messages. To move towards real-world applications, however, challenges regarding costs, lab restraints, and slow data acquisition need to be addressed. Using portable electroencephalography (EEG) and inter-subject correlation (ISC) analysis as measure of message strength, we ask whether these challenges can be met. Portable EEG was recorded while participants viewed strong and weak video health messages against risky alcohol use. Participants viewed the messages either individually or in a focus group-like setting with six participants simultaneously. For both viewing conditions, three correlated components were extracted. The topographies of these components showed a high spatial correlation with previous high-density EEG results. Moreover, ISC was strongly enhanced when viewing strong as compared to weak health messages in both the group and individual viewing conditions. The findings suggest that ISC analysis shows sensitivity to message strength, even in a group setting using low-density portable EEG. Measuring brain responses to messages in group settings is more efficient and scalable beyond the laboratory. Overall, these results support a translational perspective for the use of neuroscientific measures in health message development.