Please cite this article in press as: Sobolewski, A., et al., Impact of meditation on emotional processing—A visual ERP study. Neurosci. Res. (2011), doi:10.1016/j.neures.2011.06.002 ARTICLE IN PRESS G Model NSR-3314; No. of Pages 5 Neuroscience Research xxx (2011) xxx–xxx Contents lists available at ScienceDirect Neuroscience Research jo u r n al hom ep age: www.elsevier.com/locate/neures Impact of meditation on emotional processing—A visual ERP study Aleksander Sobolewski a,∗ , Ewa Holt b , Ewa Kublik a , Andrzej Wróbel a a Nencki Institute of Experimental Biology (Polish Academy of Sciences), Department of Neurophysiology, 3 Pasteur St., 02-093 Warsaw, Poland b Warsaw School of Social Psychology (SWPS), 19/31 Chodakowska St., 03-815 Warsaw, Poland a r t i c l e i n f o Article history: Received 30 December 2010 Received in revised form 12 April 2011 Accepted 1 June 2011 Available online xxx Keywords: Emotion Visual ERP Late positive potential Meditation EEG IAPS a b s t r a c t Impact of meditation on emotional processing, and its clinical applications, has recently drawn significant interest. In this visual event-related potential (ERP) study we investigated whether long-term medita- tion practitioners exhibit different ERP responses to the emotional load of stimuli (IAPS pictures) than control subjects with no experience in meditation. Differences were observed in the late positive poten- tial (LPP). LPP amplitude is typically greater in ERPs evoked by emotionally arousing scenes, specifically negative images, compared to neutral scenes. This effect was also replicated in our study, but not in case of meditators’ frontal scalp regions, who differed significantly in this respect from control subjects. Our findings provide support for different emotional processing in meditation practitioners: at high levels of processing meditators are less affected by stimuli with adverse emotional load, while processing of positive stimuli remains unaltered. To further confirm this observation, a long-term longitudinal random assignment study would be desirable. © 2011 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved. 1. Introduction Traditional practices commonly referred to as “meditation”, present in various cultures, are alleged to lead to heightened aware- ness, more balanced emotional behavior and other health benefits. The practices take different forms, however common features include detached observation of one’s introspective phenomena (“open monitoring” or “mindfulness” meditation) and focus on a simple object (“focused attention” or “concentrative” meditation; Lutz et al., 2008). Recently a distinct category of meditation – “auto- matic self-transcending” – has been proposed (Travis and Shear, 2010; Josipovic, 2010). The putative advantages of meditation have drawn increased clinical and scientific interest, such that it recently merited exten- sive reviews (including one commissioned by the U.S. Department of Health and Human Services; Ospina et al., 2007). The findings corroborate some effects of meditation, but, while encouraging fur- ther investigation, also criticize the frequent low quality of original research, precluding firmer conclusions (Chiesa and Serretti, 2009; Ospina et al., 2007; Cahn and Polich, 2006). Original studies that do support the effects of meditation have shown, for example, that the practice of meditation has influ- ence on the immune, endocrine and autonomic system, e.g. it causes a decrease in respiration rate, heart rate and spontaneous skin conductance response (Dillbeck and Orme-Johnson, 1987; ∗ Corresponding author. Tel.: +48 22 589 23 64. E-mail address: a.sobolewski@nencki.gov.pl (A. Sobolewski). Infante et al., 2001; Davidson et al., 2003). Aftanas and Golosheykin (2005) suggested that meditators have better capabilities to mod- erate intensity of emotional arousal. They argued that greater desynchronization in EEG alpha band combined with gamma band synchronization over anterior cortical sites in non-meditating con- trol subjects during watching an emotionally adverse movie clip represented heavier emotional workload on the controls than on meditators. Effects of meditation were reported to include increased theta/alpha band activity (e.g. Travis et al., 2002), while individuals exhibiting greater theta activity tended to have lower state and trait anxiety scores (Inanaga, 1998). Impact of meditation on emotional processing has not, however, to our knowledge, been a subject of visual event-related poten- tial (ERP) study, while visual ERPs have been consistently shown to reflect emotional processes triggered by the emotional load of the stimulus (scene, picture), and thus provide a good research tool of the human brain’s emotional responses. Particularly, the so- called late positive potential (LPP, a sustained positive component of the ERP waveform starting ca. 400–500 ms post-stimulus) was shown to increase with the emotional potency carried by the stim- uli (Codispoti et al., 2007; Olofsson and Polich, 2007; Hajcak and Olvet, 2008; for review see Olofsson et al., 2008). It was also sensi- tive to regulation of emotions and top-down modulation related to evaluation of the affective stimuli (Hajcak et al., 2006; Moser et al., 2006; Carretié et al., 2006), diminished LPP being associated with suppression of emotional reaction (Moser et al., 2006). The goal of the present experiment was therefore to investigate how meditation influences visual ERPs evoked by emotionally arousing stimuli. Rather than transient alterations 0168-0102/$ – see front matter © 2011 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved. doi:10.1016/j.neures.2011.06.002