Flicker light stimulation enhances the emotional response to music: A comparison study to the effects of psychedelics

Recent research on serotonergic psychedelics has reported enhancement of emotional responses to music, an effect that might prove relevant in the development of psychedelic-assisted therapy. Currently, little is known about the underlying mechanisms of this effect, especially how specific it is to psychedelics. Here, we use flicker light stimulation (FLS) as an alternative, non-pharmacological method to induce altered states of consciousness, and test to what degree this might also enhance the emotional response to music. Our study protocol was designed to resemble a previous study on the effects of LSD as closely as possible, to allow direct comparison of effect sizes. Twenty participants listened to emotionally evocative music in two sessions – with and without FLS – and reported on their emotional response to the music. Our sample reported similar baseline responses to participants in the original study. FLS showed a significant enhancing effect on reported music-evoked emotion of approximately half the effect-size of LSD. Additionally, we found that the experienced intensity of FLS and the prevalence of complex imagery correlated with reports of higher levels of emotional arousal. These findings suggest that visual effects are involved in the enhancement of music-evoked emotion, and motivate further exploration of non-pharmacological methods such as FLS, in line with the diverse use of altered states of consciousness to support therapeutic approaches.