This project was a huge team-effort, by @rebeccaboehme.bsky.social @paulasalamone.bsky.social @adamenmalm.bsky.social and many more. We would also like to thank our participants and the reviewers!

Together, this shows that that disrupting the self-experience through ketamine affects self-other-differentiation in a region involved in touch perception and social cognition, providing further evidence for the intricate relationship of the bodily self with the tactile sense.

Ketamine also led to increased functional connectivity of this temporoparietal region during other- vs. self-touch with several regions, including the insula and primary somatosensory cortex (S1). For S1, the strength of this increase correlated with dissociation symptoms.

The strength of this reduction correlated with ketamine-induced reductions in interoceptive awareness

As shown before, activation in the temporoparietal cortex / secondary somatosensory cortex is attenuated during self-touch compared to other-touch. This difference is preserved during ketamine administration, but clearly reduced.

We investigated this in a double-blind placebo-controlled crossover fMRI study. Participants clearly dissociated more when receiving ketamine compared to placebo.