Insomnia does not affect heart rate changes when young adults watch humorous films: An exploratory study

Emotional reactivity in insomnia is affected both subjectively and on a physiological level for negative emotional material, but little is known about reactions to positive stimuli. We here investigated whether in younger adult insomnia patients, presentation of short humorous films would lead to heart rate decreases during and after film viewing, as compared to heart rate changes when falling asleep. Investigating 20 participants with DSM-5-diagnosed insomnia and 18 participants without insomnia, we found that heart rate decreased when falling asleep, increased when watching humorous films and returned to normal values afterwards for all participants. Film-related heart rate increases were strongly related to humour ratings of the films. No differences were found between those with and without insomnia on subjective ratings of the films, film-related heart rate changes or when falling asleep. We conclude that the experience of positive daily life stimuli in younger adults is not affected by insomnia in our study, despite insomnia having a known more profound effect on negative stimuli. Future studies exploring insomnia-related autonomous nervous system responses combining different neurophysiological modalities should confirm our findings.