Meditation-induced changes in subjective time are mediated by heart-rate variability and breathing rate Damisela Linares Gutierrez 1, Sebastian Kübel 1, Anne Giersch 2,3, Stefan Schmidt 4, Karin Meissner 5, and Marc Wittmann [1] 1 Institute for Frontier Areas in Psychology and Mental Health, Freiburg, Germany 2 INSERM U1114, Strasbourg, France 3 FMTS, Psychiatry Department, University Hospital of Strasbourg, France 4 Department of Psychosomatic Medicine, University Medical Center Freiburg, Germany 5 Division Integrative Health Promotion, University of Applied Sciences, Coburg Related to conceptualizations of a relationship between meditation, subjective time, and psychophysiology, we conducted a study probing for changes in temporal integration after meditation. We employed three psychophysical tasks related to perception of sequence in the milliseconds range, the integration of metronome beats, and the perception of alternations in the ambiguous Necker cube. The tasks were administered before and after the intervention. The 91 participants were experienced mindfulness meditators who in three separate 10 minute sessions either meditated by following a meditation session (n=44) or listened to an audio play (n=47), the three counterbalanced sessions conducted on three separate days. During the intervention heart-rate and breathing rate was recorded and compared to a resting-state condition. Applying path analyses, we found several mediating and moderating effects. Regarding subjective scales, those meditators who were less aware of the passage of time felt less emotional arousal. Regarding psychophysiology and switching of the Necker cube, breathing rate significantly mediated the effect of meditation across all participants, that is, the slower breathing during meditation the slower the switching of the two aspects in the Necker cube. Additionally, a moderator effect showed that trait-mindfulness leads to slower switching times in meditators. Regarding the metronome task, and over all frequencies meditation in more experienced meditators (n > 100 hours) lead to a decrease of integration intervals. However, for the fastest (ISI = 0.3 s) and slowest (ISI = 3 s) metronome frequencies an opposite effect occurred: the larger RMSSD during meditation the larger the integration interval. Overall, these findings add evidence to meditation-induced changes in subjective time and the general notion of embodiment of mental functioning. This work was sponsored by the FUNDAÇÃO Bial, Portugal, through a grant to Marc Wittmann, Stefan Schmidt, and Karin Meissner: “Changes in subjective time as indication of increased mindfulness after meditation.” Keywords:  mindfulness meditation; temporal integration; Necker cube; metronome; sequencing Theme: duration, order, resolution, rhythms Technique: behaviour, electrophysiology Population: adult Timescale:  10-100ms, 300ms-3s, 10minutes