Contents lists available at ScienceDirect Biological Psychology journal homepage: www.elsevier.com/locate/biopsycho Dissociating meditation proficiency and experience dependent EEG changes during traditional Vipassana meditation practice Ratna Jyothi Kakumanu a,1 , Ajay Kumar Nair a,1 , Rahul Venugopal a , Arun Sasidharan a , Prasanta Kumar Ghosh b , John P. John c , Seema Mehrotra d , Ravindra Panth e , Bindu M. Kutty a, ⁎ a Department of Neurophysiology, National Institute of Mental Health and Neuro Sciences (NIMHANS), Bengaluru 560029, Karnataka, India b Department of Electrical Engineering, Indian Institute of Science (IISc), Bengaluru 560012, Karnataka, India c Department of Psychiatry, National Institute of Mental Health and Neuro Sciences (NIMHANS), Bengaluru 560029, Karnataka, India d Department of Clinical Psychology, National Institute of Mental Health and Neuro Sciences (NIMHANS), Bengaluru 560029, Karnataka, India e Department of Buddhist Philosophy, Nava Nalanda Mahavihara, Nalanda 803111, Bihar, India ARTICLE INFO Keywords: Vipassana meditation EEG Permutation entropy Fractal dimensions Neural plasticity ABSTRACT Meditation, as taught by most schools of practice, consists of a set of heterogeneous techniques. We wanted to assess if EEG profiles varied across different meditation techniques, proficiency levels and experience of the practitioners. We examined EEG dynamics in Vipassana meditators (Novice, Senior meditators and Teachers) while they engaged in their traditional meditation practice (concentration, mindfulness and loving kindness in a structured manner) as taught by S.N. Goenka. Seniors and Teachers (vs Novices) showed trait increases in delta (1–4 Hz), theta-alpha (6–10 Hz) and low- gamma power (30–40 Hz) at baseline rest; state-trait increases in low-alpha (8–10 Hz) and low-gamma power during concentrative and mindfulness meditation; and theta-alpha and low-gamma power during loving-kind- ness meditation. Permutation entropy and Higuchi fractal dimension measures further dissociated high profi- ciency from duration of experience as only Teachers showed consistent increase in network complexity from baseline rest and state transitions between the different meditation states. 1. Introduction Meditation is an umbrella term for a set of heterogeneous techni- ques that engage several different neurocognitive processes and typi- cally induce beneficial effects on brain and behavior (Boccia, Piccardi, & Guariglia, 2015; Fox et al., 2016; Nair, Sasidharan, John, Mehrotra, & Kutty, 2017). A recent attempt at classifying meditative practices based on cognitive mechanisms acknowledged that many meditative practices might span multiple categories (Dahl, Lutz, & Davidson, 2015). As an example, mindfulness based meditation has aspects of concentration, mindfulness and loving kindness (Manuello, Vercelli, Nani, Costa, & Cauda, 2016) and thus straddles the attentional, constructive and de- constructive families (Dahl et al., 2015). We had three considerations while undertaking the present study. Since mindfulness might mean several different things (Davidson & Kaszniak, 2015), the first consideration was to specify the context under which a study is carried out. In particular, the traditional practice and philosophical position underlying the meditative practice needs to be articulated (Awasthi, 2013). EEG studies examining the neurophy- siology of mindfulness based meditation techniques have found con- sistent changes in theta and alpha power (Cahn & Polich, 2006; Lomas, Ivtzan, & Fu, 2015). This might imply that there are at least some common mechanisms underlying these meditation techniques as they finally involve some aspect of mindfulness (Manuello et al., 2016). On the other hand, it is possible that a context based study of mindfulness meditation might reveal a more nuanced understanding of the neuro- physiological underpinnings of the different meditative techniques. The second consideration was that long term practice has a trait influence on meditation state (Davidson & Kaszniak, 2015). Several studies examine the influence of duration of practice on meditation state by comparing EEG changes in long term meditators in comparison to novice meditators. The challenge is that there is wide variability in https://doi.org/10.1016/j.biopsycho.2018.03.004 Received 10 September 2017; Received in revised form 5 March 2018; Accepted 5 March 2018 ⁎ Corresponding author at: Department of Neurophysiology, National Institute of Mental Health and Neuro Sciences (NIMHANS), P.B. No. 2900, Dharmaram P.O, Hosur Main Road, Bengaluru 560029, Karnataka, India. 1 These authors contributed equally to this work. E-mail addresses: jyothi.maanu@gmail.com (R.J. Kakumanu), ajay.nimhans@gmail.com (A.K. Nair), rahul.nimhans@gmail.com (R. Venugopal), arunsasi84@gmail.com (A. Sasidharan), prasantag@gmail.com (P.K. Ghosh), jpjinc@yahoo.com (J.P. John), drmehrotra_seema@yahoo.com (S. Mehrotra), panthr2011@gmail.com (R. Panth), bindu.nimhans@gmail.com (B.M. Kutty). Biological Psychology 135 (2018) 65–75 Available online 08 March 2018 0301-0511/ © 2018 Elsevier B.V. All rights reserved. T