Attending to the present: mindfulness meditation reveals distinct neural modes of self-reference
Norman A. S. Farb1, Zindel V. Segal1,2, Helen Mayberg3, Jim Bean4, Deborah McKeon4, Zainab Fatima5 and Adam K. Anderson1,5
1Department of Psychology, University of Toronto, ON M5S 3G3, Canada, 2Department of Psychiatry, University of Toronto and Centre for Addiction and Mental Health, Toronto, ON M5T 1R8, Canada, 3Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA 30322, 4Mindfulness-Based Stress Reduction (MBSR) Clinic, St. Joseph's Health Centre, Toronto, Ontario, Canada, M6R 1B5, and 5Rotman Research Institute, Baycrest, Toronto, Ontario, M6A 2E1
It has long been theorised that there are two temporally distinct forms of self-reference: extended self-reference linking experiences across time, and momentary self-reference centred on the present. To characterise these two aspects of awareness, we used functional magnetic resonance imaging (fMRI) to examine monitoring of enduring traits (’narrative’ focus, NF) or momentary experience (’experiential’ focus, EF) in both novice participants and those having attended an 8 week course in mindfulness meditation, a program that trains individuals to develop focused attention on the present. In novices, EF yielded focal reductions in self-referential cortical midline regions (medial prefrontal cortex, mPFC) associated with NF. In trained participants, EF resulted in more marked and pervasive reductions in the mPFC, and increased engagement of a right lateralised network, comprising the lateral PFC and viscerosomatic areas such as the insula, secondary somatosensory cortex and inferior parietal lobule. Functional connectivity analyses further demonstrated a strong coupling between the right insula and the mPFC in novices that was uncoupled in the mindfulness group. These results suggest a fundamental neural dissociation between two distinct forms of self-awareness that are habitually integrated but can be dissociated through attentional training: the self across time and in the present moment.
Keywords: self-reference; attention; meditation; fMRI; insula; prefrontal cortex; somatosensory; plasticity