Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.08.28.262550v1?rss=1 Authors: Livermore, J. J. A., Holmes, C. L., Moga, G., Adamatzky, K., Critchley, H., Garfinkel, S., Campbell-Meiklejohn, D. Abstract: Interoception is the signaling, perception, and interpretation of internal physiological states. A causal link between serotonin and interoception was tested by a within-participant, crossover, placebo-controlled study. Forty-seven healthy human volunteers were tested on and off a 20mg oral dose of the selective serotonin reuptake inhibitor (SSRI) citalopram. For each randomly ordered session, participants made a series of judgements about the synchrony of their heartbeat to auditory tones and expressed confidence in each judgement. Citalopram enhanced insight into the likelihood that a correct interoceptive judgement occurred, driven primarily by increased confidence in correct judgements. This effect was independent of measured physiological and subjective effects of the drug and greater than a null effect on insight into exclusively exteroceptive performance on a visual task. This finding provides a foundation for considering effects of serotonin on cognition, emotion, and behaviour in terms of higher order processing of interoceptive events. Copy rights belong to original authors. Visit the link for more info