Meditation, mindfulness and cognitive flexibility

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Abstract

This study investigated the link between meditation, self-reported mindfulness and cognitive flexibility as well as other attentional functions. It compared a group of meditators experienced in mindfulness meditation with a meditation-naïve control group on measures of Stroop interference and the “d2-concentration and endurance test”. Overall the results suggest that attentional performance and cognitive flexibility are positively related to meditation practice and levels of mindfulness. Meditators performed significantly better than non-meditators on all measures of attention. Furthermore, self-reported mindfulness was higher in meditators than non-meditators and correlations with all attention measures were of moderate to high strength. This pattern of results suggests that mindfulness is intimately linked to improvements of attentional functions and cognitive flexibility. The relevance of these findings for mental balance and well-being are discussed.

Introduction

In recent years the interest in the effects of buddhist meditation practice has been growing rapidly (Barinaga, 2003, Ekman et al., 2005, Knight, 2004). In particular, the benefits of utilising meditation as therapeutic measure in the health care setting have been discussed and meditation-based interventions are increasingly being implemented adjunct or complementary to classical medical or psychological approaches. The most popular approach within this emerging field is probably the mindfulness-based stress reduction programme (MBSR) developed by Jon Kabat-Zinn in the early 1980s (e.g. Kabat-Zinn, 1984, Kabat-Zinn, 1990, Kabat-Zinn et al., 1985). While the programme is rapidly gaining in popularity and has been subjected to numerous evaluation studies covering a variety of physical and psychological disorders, its effectiveness is not yet established beyond any doubt (Baer, 2003, Bishop, 2002, Grossman et al., 2004). Similarly, the mechanisms how meditation practice and improvement in mindfulness contribute to physical as well as psychological well-being are not well understood (Brown et al., 2007, Malinowski, 2009).

An alternative perspective on buddhist meditation practice is concerned with cognitive, emotional and neurophysiological changes resulting from extensive meditation practice, where meditation is often conceptualised in terms of mental or cognitive training (e.g. Cahn and Polich, 2006, Carter et al., 2005, Slagter et al., 2007). Results are frequently discussed with respect to neuroplasticity, as several findings suggest that extended meditation training may lead to functional as well as structural changes of the brain (e.g. Davidson et al., 2003, Lazar et al., 2005, Lutz et al., 2004, Pagnoni and Cekic, 2007).

These two approaches provide different perspectives which contribute to a broader understanding of the processes and effects of meditation practice. In an attempt to align western psychological and buddhist thinking about this topic, Wallace and Shapiro (2006) provide a framework that facilitates the integration of such different perspectives. Drawing from buddhist sources as well as psychological theory and evidence they propose a four-component model, outlining areas for development that contribute to overall psychological well-being. According to their mental balance model the components conation (motivation, intention), attention, cognition and affect/emotion need to be developed and balanced to achieve profound well-being. In particular, though not exclusively, the components attention and cognition bear a close relationship to mindfulness (see Malinowski, 2009), which has been conceptualised in terms of self-regulation of attention and orientation towards one’s experiences (Bishop et al., 2004). Also Kabat-Zinn’s operational definition of mindfulness as “the awareness that emerges through paying attention on purpose, in the present moment, and non-judgmentally to the unfolding of experience moment by moment” (Kabat-Zinn, 2003, p. 145) acknowledges these two aspects. Thus, mindfulness meditation encompasses various aspects of attention as for instance the ability to focus and sustain ones attention and a reduced proneness to distraction. Cahn & Polich’s definition of meditation as “practices that self-regulate the body and mind, thereby affecting mental events by engaging a specific attentional set” (Cahn & Polich, 2006, p. 180), also indicates that training of attentional functions is an essential aspect of any form of meditation practice. In a similar way traditional buddhist texts describe the practice of bare attention, the attending “to the bare facts of perception without reacting to them by deed, speech or mental comment”, as a corner stone of mindfulness (Thera, 2005, p. 3). To cultivate mindful awareness, attention needs to be combined with a non-judgmental orientation towards and openness for the flow of one’s experiences.

The aim of the current study is to investigate attentional functions and in particular cognitive flexibility within the theoretical framework outlined above. As Roemer and Orsillo (2003) argue, research that examines the effect of mindfulness on cognitive flexibility is currently lacking. Cognitive flexibility is here understood as the human ability to adapt cognitive processing strategies to face new and unexpected conditions and is intrinsically linked to attentional processes (Cañas, Quesada, Antolí, & Fajardo, 2003). As mindfulness meditation is dependant on the (re-)investment of attention on a moment by moment basis, mindfulness training should hypothetically lead to increased cognitive flexibility and an increased ability to respond in a non-habitual fashion.

In this study we are employing two well-established measures, the Stroop task (Stroop, 1935) and the d2-test of attention (Brickenkamp & Zilmer, 1998), to test participants’ ability to suppress interfering information and to focus and direct their attention. As these skills are characteristic of good cognitive flexibility and are practiced during mindfulness training, individuals who practice mindfulness meditation should perform well on such tasks. Although recent research suggests a positive relation between meditative practice and attentional function (Jha et al., 2007, Pagnoni and Cekic, 2007, Slagter et al., 2007, Valentine and Sweet, 1999), a clear link between mindfulness and cognitive flexibility still needs to be established. Only few studies attempted to do so by employing the Stroop paradigm. Wenk-Sormaz’s (2005) showed that engaging in meditative practice resulted in a reduction of Stroop interference. However, a study by Anderson and co-workers failed to find an improvement of attentional functions after participation in an 8-week MBSR-programme as assessed by various measures of attention, attention switching and Stroop interference (Anderson, Lau, Segal, & Bishop, 2007). Thus, evidence for a relation between mindfulness and attentional functions remains ambiguous. An important difference between Anderson et al.’s (2007) study and that by Wenk-Sormaz (2005) is that the latter measured the effects of brief exposure to mindfulness meditation immediately after the end of the last of three 20 min meditation sessions, administered over the course of 2 weeks. In comparison, Anderson et al. investigated the effects of a more expansive mindfulness training (8-weeks) which usually also includes other aspects such as psychological education and physical exercises, and the tests took place up to 4 weeks after completion of the programme, preceded by a 10 min meditation session. A further difference between these studies is that Anderson et al. employed a modified version of the Stroop task, which originally was developed to assess the self-representation of clinical patients (Segal, Gemar, Truchon, Guirguis, & Horowitz, 1995) rather than the standard Stroop task employed by Wenk-Sormaz. Thus, not finding a reduction of Stroop interference in Anderson et al.’s study may be attributed to the fact that the employed task does not tap attentional functions per se but rather measures the interference of cognitive and affective content on behavioural responses. As in both studies the tests were carried out immediately following the experimental induction of mindfulness, one may, furthermore, argue that the findings only apply to this specific situation, whereas the ecologically more important question regarding changes that pertain to everyday life, were not addressed.

To sum up, the link between cognitive flexibility and mindfulness and its possible relevance for everyday life remains unclear.

Following these ideas, in our study we are comparing a group of meditators with experience in mindfulness meditation with a group of non-meditators on several tests of attention and assess them in a quiet experimental situation, but without inducing a meditative state or state of mindfulness. Furthermore, for estimating their levels of mindfulness, they are required to complete a mindfulness self-report questionnaire, the Kentucky Inventory of Mindfulness Skills (KIMS, Baer, Smith, & Allen, 2004). This approach allows us to compare between meditators and non-meditators and additionally to investigate the relation between mindfulness and cognitive control more closely.

The concurrent use of the d2-test of attention and the Stroop task enables us to test the ability to focus, sustain and direct ones attention and to suppress interfering information. As cognitive flexibility implies the ability to interrupt or deautomatise automated responses, that is to respond non-habitually, we shall briefly introduce the concepts of automatisation and deautomatisation in relation to meditative practice.

According to Shiffrin and Schneider (1977) cognitive processes can typically be classified as being either controlled or automatic. They suggested that automatic processes operate in parallel and independent of attention, “automatic [processes] do not require attention, though they may attract it if training is inappropriate, and they do not use up short-term memory capacity” (Shiffrin & Schneider, 1977, p. 38). Spelke, Hirst, and Neisser (1976) have also stressed that behaviour should only be termed ‘automatic’ if it did not involve certain high-order attentional skills. Additionally, Spelke et al. have shown that whilst certain processes may be thought of as innately automatic, others may become automatic through practice. It is generally accepted that once automated these processes are thought to be initiated unintentionally and effortlessly. Consequently they cannot be easily interrupted or prevented. Numerous researchers (for example Dyer, 1973, Virzi and Egeth, 1985) have proposed that reading is seen as an automatic process, acquired through extensive practice and long-term learning literate adults experienced. The Stroop effect (Stroop, 1935) evidences the difficulty of interrupting the automatic process of reading of words in proficient readers. During the Stroop task participants are asked to attend to the colour in which words are printed, not to the semantics of the words. Participant’s responses are significantly slower and less accurate when asked to identify the colour of an incongruent colour word compared with responses to neutral and congruent words (MacLeod, 1991). In line with Stroop’s account, theories most often explain the Stroop asymmetry as a consequence of automaticity (see Hasher and Zacks, 1979, LaBerge and Samuels, 1974, Logan, 1980). The automatic semantic activation of the word meaning must be overridden in order for participants to respond correctly when faced with incongruent words. As reading is automatic for proficient readers less attentional resources are required for reading irrelevant (neutral) words than for ink colour naming. Consequently, the reading of the word appears obligatory and results in an increase in reaction times and errors when attempting to process incongruent colour words. Increasing the performance in this task would therefore require the reinvestment of attention (deautomatisation) and a non-habitual response.

There is much debate as to whether processes that have become automatised can be brought back under top down control. In view of Shiffrin and Schneider’s (1977) suggestion that automatised processes act independently of attention, it has been proposed that deautomatisation is achieved through the reinvestment of attention in actions and behaviours (Deikman, 1963, Deikman, 1966, Deikman, 2000). Considering the definition of mindfulness as “bringing one’s complete attention to the present experience on a moment-to-moment basis” (Marlatt & Kristeller, 1999, p. 68), the potential link to processes of deautomatisation becomes obvious. If mindfulness-based meditation training improves the ability to invest one’s attention to the present moment, it should be possible to bring processes that became automatised by extensive practice back under cognitive control.

In the current study we thus expected to find a reduction in Stroop interference as well as improvement in focused attention and processing speed (as measure of sustained attention) in a group of buddhist meditators experienced in mindfulness meditation compared to a meditation-naïve control group.

We furthermore expected to find higher self-reported mindfulness in the meditation group and a positive correlation between mindfulness and the different measures of attentional performance and cognitive control. The KIMS consists of four sub-scales which allows breaking down mindfulness into several components (Baer et al., 2004). Observing (1) highlights the importance of observing and noticing the full variety of external and internal stimuli. As many forms of mindfulness training include the practice of naming and labelling of the observed phenomena (e.g. Thera, 2005), describing (2) captures the resulting ability to verbalise experiences. Acting with awareness (3) implies the ability to pay undivided attention to the activity one is carrying out (e.g. Hanh, 1987), without getting distracted. Finally, accepting without judgment (4) covers the aspect of being non-judgemental or non-evaluative about the present moment and thus implies the ability to refrain from automatic responses.

When investigating these sub-components of mindfulness, we expected that the two facets acting with awareness and accepting without judgment will exhibit the strongest correlations with task performance as these two facets most clearly capture the aspects of inhibition of irrelevant and distracting information as well as the deautomatisation of cognitive function.

Section snippets

Participants

The study used two groups, a meditation group and a matched meditation-naïve control group. Group one consisted of 25 buddhist meditators, who were recruited from a local buddhist centre, where meditation practices that particularly focus on mindfulness meditation are taught. Most of the buddhist participants were enrolled in intermediate classes and had at least completed a 6-week beginners course on meditation. The control group consisted of 25 non-meditators. The majority were recruited from

Results

As can be seen in Table 2, KIMS total scores were significantly correlated with each of the examined variables (also see Fig. 1 for the most important correlations). Positive correlations were found with the d2-scores TN (r = .510, p < .001), TN  E (r = .620, p < .01), CP (r = .667, p < .01) and the Stroop-score TNP (r = .331, p < .05). This indicates that high levels of mindfulness are correlated with high processing speed, good attentional and inhibitory control, and a good coordination of speed with

Discussion

This investigation into the link between meditation, self-reported mindfulness and cognitive flexibility overall suggests that attentional performance and cognitive flexibility are positively related to meditation practice and levels of mindfulness. Meditators performed significantly better than non-meditators on all measures of attention. Furthermore, self-reported mindfulness was higher in meditators than non-meditators and correlations with all attention measures were of moderate to high

Conclusions

The finding that regaining or increasing attentional control and cognitive flexibility seems possible may have further implications beyond the domain of cognitive psychology. Within Wallace and Shapiro’s (2006) mental balance model, attentional and cognitive balance play an important role in promoting well-being. They make the case that meditation training and the cultivation of mindfulness improve these aspects of mental balance and in conjunction with conative and affective balance contribute

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