Error processing and mindfulness meditation in female students

Highlights

• Meditation and PMR resulted in stress reduction and increased mindfulness.

• Meditation and PMR did not differentially affect error processing.

• Error negativity did not change after 4 weeks training.

• Error positivity increased for both meditation and PMR.

Abstract

Mindfulness seems to have an impact on error processing in simple response tasks, as former studies reported both an effect of mindfulness meditation on, as well as relationships to trait mindfulness with behavioral and neural correlates of error processing. However, the results of these studies showed no consistent pattern. To dismantle some of these findings, this study investigated the impact in female students of a four-week, smartphone-based mindfulness training program (N = 22) in comparison with an active control group that did progressive muscle relaxation (PMR; N = 20). In addition to behavioral data, two error-related components of the event-related potential were measured with electroencephalogram while performing a combination of a modified Simon task and an error detection paradigm, namely error-related negativity and error positivity. Mindfulness meditation did not have a differential effect on error components in comparison to PMR. For both, we found a reduction of stress symptoms, an increase in mindfulness and an increase in error positivity.

Introduction

Mindfulness, the awareness of the present moment by regulating attention towards the experience, and emotional acceptance by staying curious and open towards any experience (Bishop et al., 2004), can be enhanced by practice of mindfulness meditation (Ortner et al., 2007). The therapeutic, stress reducing effects of mindfulness meditation (Chiesa and Serretti, 2009; Godfrin and van Heeringen, 2010) might be mediated by strengthening performance monitoring, attention, and/or emotion regulation systems (Chambers et al., 2009; Davidson and Lutz, 2008; Gu et al., 2009; Hofmann and Asmundson, 2008; Moore and Malinowski, 2009; Teasdale et al., 1995; Way et al., 2010). Mindfulness Meditation has been found to increase activation in the dorsal ACC and the dorsolateral PFC (Baron Short et al., 2010), and the ACC has been shown to be an important neural source involved in error processing (e.g., Dehaene et al., 1994). This study sought to explore if and how error processing was affected by mindfulness meditation and how this might be linked to beneficial outcomes.

The error negativity or error-related negativity (Ne/ERN; Falkenstein et al., 1991; Gehring et al., 1993) and error positivity (Pe; Falkenstein et al., 2000; Vocat et al., 2008) are two components of the event-related potential (ERP) reflecting electrophysiological correlations of errors. The Ne/ERN was interpreted as an indicator of both conflict monitoring (Botvinick et al., 1999; van Veen and Carter, 2002; Yeung et al., 2004), and error processing (Falkenstein et al., 2000; Holroyd et al., 1998). While the Ne/ERN might reflect a preconscious neural process (Endrass et al., 2005; O'Connell et al., 2007), the Pe seems to reflect a conscious or aware error process (Dehaene et al., 2006; Endrass et al., 2007; Nieuwenhuis et al., 2001; O'Connell et al., 2007) and error evidence accumulation related to working memory (Steinhauser and Yeung, 2010; Di Gregorio et al., 2016; Di Gregorio et al., 2018). When a Ne/ERN occurs without a following Pe, the error might have been processed by preconscious, but not by conscious error processing. A reduced Pe amplitude was interpreted as an indicator of less intense salience of errors (Hajcak et al., 2004), as a result of fewer neural resources for conscious error processing and as a general working memory reduction after sleep deprivation (Murphy et al., 2006) as well as under hypnosis (Kaiser et al., 1997).

Assuming that mindfulness meditation enhances awareness and emotional acceptance, error processing and its neural correlates (Ne/ERN and Pe) might be affected. If meditation reduces negative affect (Lutz et al., 2007), Ne/ERN should be decreased after a meditation training, as less neural resources are required to re-allocate attention from worrying to error monitoring (Moser et al., 2013). Participants with higher trait mindfulness scores showed an Ne/ERN difference between detected and non-detected errors, possibly indicating earlier awareness during error detection for more mindful participants (Eichel and Stahl, 2017). By contrasting experts vs. non-experts of meditation, Teper and Inzlicht (2013) found that the Ne/ERN amplitude increased for participants with high emotional acceptance, as a facet of the mindfulness trait. Fissler et al. (2017) found an Ne/ERN increase after a mindfulness training but not in a resting control condition, only for people with depression compared to healthy control participants.

Given that the Pe indicates strength of error evidence accumulation (Steinhauser and Yeung, 2010), a higher Pe amplitude could indicate that more activity was either needed or available to bring an error to awareness. Therefore, the training of awareness could lead to a decreased Pe amplitude for detected errors if less activity is needed for error evidence. In one study, Pe amplitude on erroneous trials was higher for participants of a control group than the meditation group (Larson et al., 2013). Teper and Inzlicht (2013) did not find significant effects of meditation on the Pe amplitude (see also Andreu et al., 2017; Smart and Segalowitz, 2017). However, if the degree and capacity of awareness of an error is directly displayed by the magnitude of the Pe amplitude (as shown under hypnosis, Kaiser et al., 1997), i.e., a higher capacity of awareness indicated by a higher Pe amplitude, then post awareness training could also display a higher Pe amplitude than pre-training.

Our study aimed at investigating error detection (Eichel and Stahl, 2017) in individuals before and after a mindfulness meditation training, with a control group doing progressive muscle relaxation (PRM), to address some of the limitations of former studies (Eichel and Stahl, 2017; Fissler et al., 2017; Larson et al., 2013; Teper and Inzlicht, 2013).

Besides investigating possible behavioral changes regarding errors and response times, we predicted that only participants in the mindfulness-based training group would show an increase in awareness, both general awareness and error awareness (cf., Hölzel et al., 2007; Teper & Inzlicht, 2012), indicated by changes in ERPs and a higher sensitivity to detected errors. Considering the heterogeneity of previous research on Ne/ERN and mindfulness, a direction of effect cannot be predicted: a training in mindfulness might not affect Ne/ERN amplitude at all (Larson et al., 2013); Ne/ERN might increase in case of previous attenuation of amplitude due to possible depression in our cohort (Fissler et al., 2017); or there might be a differential effect for detected errors and undetected errors after the mindfulness training (Eichel and Stahl, 2017). Furthermore, we explored whether increased mindfulness affects Pe and in what direction. If Pe reflects the strength of evidence accumulation (Steinhauser and Yeung, 2010) or is directly related to error awareness (Hajcak et al., 2004), we expected a training-related Pe amplitude modification within the mindfulness-based group compared to no change in the PMR group. If the mindfulness-based training leads to an increase in emotional acceptance, a reduction of motivational reactivity to errors could also lead to a decrease of the Pe.