LSD modulates music-induced imagery via changes in parahippocampal connectivity.

Psychedelic drugs like LSD are being re-examined for therapeutic use, often combined with music during psychotherapy. In a placebo-controlled fMRI study with 12 healthy volunteers, researchers investigated how LSD and music together affect mental imagery. They found that the combination of LSD and music increased functional connectivity and information flow from the parahippocampal cortex to the visual cortex. This enhanced connectivity correlated with stronger eyes-closed visual imagery, including autobiographical imagery. The findings suggest a neural mechanism by which music and LSD synergistically enhance subjective experiences that may be valuable in therapeutic settings.

Study at a glance

Abstract

Psychedelic drugs such as lysergic acid diethylamide (LSD) were used extensively in psychiatry in the past and their therapeutic potential is beginning to be re-examined today. Psychedelic psychotherapy typically involves a patient lying with their eyes-closed during peak drug effects, while listening to music and being supervised by trained psychotherapists. In this context, music is considered to be a key element in the therapeutic model; working in synergy with the drug to evoke therapeutically meaningful thoughts, emotions and imagery. The underlying mechanisms involved in this process have, however, never been formally investigated. Here we studied the interaction between LSD and music-listening on eyes-closed imagery by means of a placebo-controlled, functional magnetic resonance imaging (fMRI) study. Twelve healthy volunteers received intravenously administered LSD (75µg) and, on a separate occasion, placebo, before being scanned under eyes-closed resting conditions with and without music-listening. The parahippocampal cortex (PHC) has previously been linked with (1) music-evoked emotion, (2) the action of psychedelics, and (3) mental imagery. Imaging analyses therefore focused on changes in the connectivity profile of this particular structure. Results revealed increased PHC-visual cortex (VC) functional connectivity and PHC to VC information flow in the interaction between music and LSD. This latter result correlated positively with ratings of enhanced eyes-closed visual imagery, including imagery of an autobiographical nature. These findings suggest a plausible mechanism by which LSD works in combination with music listening to enhance certain subjective experiences that may be useful in a therapeutic context.