Elsevier

Neuroscience Research

Volume 71, Issue 1, September 2011, Pages 44-48
Neuroscience Research

Impact of meditation on emotional processing—A visual ERP study

https://doi.org/10.1016/j.neures.2011.06.002Get rights and content

Abstract

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 meditation 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 potential (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.

Highlights

► Visual ERPs reveal altered emotional processing in meditation practitioners. ► At high processing levels meditators are less affected by adverse emotional stimuli. ► Conversely, processing of positive stimuli remains unchanged.

Introduction

Traditional practices commonly referred to as “meditation”, present in various cultures, are alleged to lead to heightened awareness, 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 – “automatic 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 extensive 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 further 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 influence 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, Infante et al., 2001, Davidson et al., 2003). Aftanas and Golosheykin (2005) suggested that meditators have better capabilities to moderate 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 control 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 potential (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 stimuli (Codispoti et al., 2007, Olofsson and Polich, 2007, Hajcak and Olvet, 2008; for review see Olofsson et al., 2008). It was also sensitive 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 appearing during actual meditation sessions (i.e. states), we intended to capture long-term effects of meditation practice, revealing lasting reorganization of emotional processes (i.e. traits).

Section snippets

Participants

Twenty six individuals were included in the study. Thirteen (7 men and 6 women; aged 38.7 ± 9.8 years, mean ± standard deviation), who have been practicing Buddhist meditation, formed a ‘meditators’ group. The ‘control’ group (n = 13, 5 men and 8 women; aged 34.6 ± 6.5 years) were recruited from healthy volunteers with no experience of meditation. There were no significant age differences between the groups (p = 0.40, Wilcoxon's rank sum test), nor did the gender ratios in the groups differ significantly

Results

Fig. 1 illustrates group mean (i.e. grand average) ERPs registered in our study. There is, as expected (see Section 1), an evident increase of the LPP amplitude in response to stimulus negativity in control subjects (Fig. 1A). However, interestingly, there is no such effect, or only an inconspicuous increase, in meditators’ group (Fig. 1B). On the other hand, stimulus positivity elicited only modest LPP variations in both groups, which were similar in both control (Fig. 1C) and meditators’ (

Discussion

The present visual ERP study provides evidence for a long-term effect of meditation practice on the brain's emotional processing. We found that – in contrast to the control subjects – meditators’ ERPs, specifically over frontal regions, were not impacted by negative pictures (there was no increase in the LPP components of ERP). On the other hand, we found no difference in LPP response to emotional positivity of images between meditators and control participants. This allows us to posit that

References (27)

  • L. Aftanas et al.

    Impact of regular meditation practice on EEG activity at rest and during evoked negative emotions

    International Journal of Neuroscience

    (2005)
  • B.R. Cahn et al.

    Meditation states and traits: EEG, ERP, and neuroimaging studies

    Psychological Bulletin

    (2006)
  • L. Carretié et al.

    Neural response to sustained affective visual stimulation using an indirect task

    Experimental Brain Research

    (2006)
  • Cited by (60)

    • Effects of a creative yoga intervention on the joint attention and social communication skills, as well as affective states of children with Autism Spectrum Disorder

      2021, Research in Autism Spectrum Disorders
      Citation Excerpt :

      Additionally, neuroimaging and electrophysiological studies have shed light on the impact of yoga on the emotional processing abilities of yogis. For example, prolonged practice of yoga/meditation led to increased activation in the medial/orbitofrontal cortices, i.e. regions important for emotional processing (Hölzel et al., 2007) as well as lower responses to negative emotional stimuli (or lower event-related potentials) (Sobolewski et al., 2011). Similarly, children with attentional deficits between 6 and 10 years increased the percent of eye contact with their teacher as well as increased attentional focus on the class activities after 3 weeks of yoga intervention delivered twice a week (Peck et al., 2005).

    • Emotional processing changes of qigong on college students: A pilot ERP study of a randomized controlled trial

      2021, Journal of Traditional Chinese Medical Sciences
      Citation Excerpt :

      Therefore, the presumptive emotion regulation of mind-body exercises has aroused great interest in the scientific community, especially in the field of neuroscience.12‒14 Studies have shown that the influence of meditation might transfer to the non-meditative state, and meditation could reduce the interference of negative emotions and make emotion regulation easier.15‒17 The mind adjustment of qigong is also known as the refining of the spirit or self-training, which aims at changing the daily state of mind from the extrovert to the introvert state.18

    View all citing articles on Scopus
    View full text