Harmonic insights
Unveiling psychedelic mechanisms through music
by Rebecca Harding and Leor Roseman

Beyond the emotional experiences of patients, differences in brain activity were observed between the two treatments. We examined how the brain processes ‘musical surprises’ during the song, which are linked to feelings of reward and pleasure—the ubiquitous ‘chills’ experienced when listening to music. Those who had received psilocybin therapy showed decreases in the activity of the ventromedial prefrontal cortex, whereas there was no change in those who had received escitalopram. This area, one of the higher-order processing areas in the brain, is linked to the executive control of emotion and is part of the default mode network. This network is shown to be active when the mind is focussed on the internal world and has been shown to be pathologically increased in depression. Therefore, a reduction in this area may indicate that psilocybin therapy causes a decrease in top-down control in emotional processing, thereby expanding the bandwidth of emotions experienced. Coupled with the finding that psilocybin therapy increases activation in sensory processing areas, this may be interpreted as a shift from excessively internal processing and rumination to a more external, sensory-driven mode which is characteristic of recovery from depression.

Perhaps this might explain the results we have observed out of the lab, beyond the clinical findings, which resonate with the human experience as a whole. As we know, music has the potential to cross linguistic and cultural barriers, but with the help of psychedelics, this capacity is heightened (Roseman et al., 2021). For instance, in our exploration of the relational dynamics of Israeli-Palestinian ayahuasca groups, participants reported experiencing a profound sense of recognition and connection with ‘the Other’ culture when listening to their music under the influence of ayahuasca. This connection induced feelings of awe in individuals, which is associated with the breaking down of mental barriers and the inclusion of what was previously excluded from mental structures. When these rigid frameworks dissolve, individuals are able to forge connections in surprising and rewarding ways. Therefore, perhaps this experience that we have captured during the surprising element of music harks to this component of human nature, and the feelings of connectedness through which we might be relieved of our unhealthy emotional processing. 

Also, our results echo the findings of previous studies that have revealed persisting changes in music-evoked emotion, outlasting the effects of the drug and providing a testament to the powerful implications of psychedelic therapy in improving our emotional processing. Previous studies in our lab revealed decreased music-evoked ‘sadness’ and increased music-evoked ‘peacefulness’ one day following psilocybin therapy (Shukuroglou et al., 2023). Likewise, that study observed changes in brain activity from before to after psilocybin therapy, with reductions in the connectivity of the nucleus accumbens, a region crucial to reward processing, with areas in the default mode network. This indicates a reduction in the activity of regions with a more top-down influence on how we understand the world around us and instead allows us to be more present with the incoming sensory information from the world around us.

Indeed, as with all scientific research, our research was not without its limitations. The emotion and reward one experiences during music listening is incredibly idiosyncratic; a reminder of the complexity and subjectivity inherent in the emotional lives of humans. The feelings that may arise when listening to music may be affected by a miscellany of factors, such as musical taste, cultural background, and personality traits. What might resonate as a chorus of angels to one person could be perceived as a nightmarish cacophony by others. As Humphrey Osmond articulately put it, ‘To fathom hell or soar angelic…’ – check out our playlist. 

Given that we only used one song for all participants, our ability to fully capture the nuances of music-evoked emotion and pleasure across the different treatments may be constrained. However, following rigorous scientific procedure, this afforded us control over the variables experienced by participants in the confines of the scanner. If only neuroimaging were cheaper and more convenient, and our capacity for inquiry boundless, our explorations into the mind would go deeper, and our playlists more extensive. Perhaps future research could explore more individualised playlists or a more diverse selection of musical genres to better accommodate for individual preferences and emotional responses. Nonetheless, despite these obstacles, we continue with gratitude to use music in our research, providing insights into the psychopharmacological and emotional changes spurred by these treatments and revealing where the harmony of healing resides.