The Lived Experiences of Experienced Vipassana Mahasi Meditators: an Interpretative Phenomenological Analysis

Research into the effects and mechanisms of mindfulness training draws predominantly on quantitative research. There is a lack of understanding about the subjective experiences of experienced mindfulness meditators, which may provide additional insights into the effects, processes and context of mindfulness training. This qualitative study explored the lived experiences of a novel group of experienced mindfulness meditators who practise Vipassana Mahasi (VM) meditation. The study aimed to understand how experienced VM practitioners make sense of the effects of practice and what processes they ascribe to it. Participants attended semistructured interviews, and their responses were analysed using interpretative phenomenological analysis. Results yielded overarching themes including (a) improvements in hedonic and eudaimonic well-being; (b) insights into self, others and perception of reality; (c) attaining equanimity; and (d) physical and interpersonal difficulties. Participants perceived VM as a ‘cleansing’ process whereby maladaptive responses were eliminated through mindfulness, other supportive mental qualities, decentering and nonattachment. The findings revealed a complex and dynamic set of interdependent outcomes and processes, which are reinforced by Buddhist teachings and ethical practices. This study highlights the need for additional interdisciplinary research into topics such as insight generation and supportive mental qualities cultivated during VM, novel states of well-being informed by Buddhist constructs and interpersonal difficulties related to long-term practice. Findings also suggest that incorporating Buddhist teachings and ethics into mindfulness-based interventions may enhance practitioner understanding and implementation of meditation techniques.

Mindfulness, as taught and practised within Buddhist meditation practices and mindfulness-based interventions (MBIs), is a complex and multifaceted construct, which eludes a universal definition . Nevertheless, within the Western psychological literature, it is often described as paying attention to present moment experiences with a nonevaluative and accepting attitude (Bishop et al. 2004;Dahl et al. 2015).
The techniques used by two of the most widely used and evidence-based MBIs, that is, mindfulness-based stress reduction (Kabat-Zinn 1990) and mindfulness-based cognitive therapy (Segal et al. 2002), have their roots in classical Buddhist insight or Vipassana meditation, specifically within the Vipassana Goenka (VG) (Hart 1987) and Vipassana Mahasi (VM) (Mahasi 2016) traditions (Gilpin 2008). Vipassana meditation, through the development of mindfulness, aims to generate a clear understanding of the nature of reality according to Buddhist teachings (Harvey 2015). While both VG and VM meditation traditions share this aim, they employ different techniques. VG is characterized by the use of focused attention directed towards the breath at the nostrils, as well as bodily sensations by means of a systematic body scanning technique (Hart 1987). VM involves a more open and flexible awareness: following an initial observation of the physical sensations related to breathing at the abdomen area, the meditator notes all mental and physical phenomena appearing in their stream of consciousness (Mahasi 2016).
The salutary effects of mindfulness training, through Buddhist mindfulness practices such as Vipassana meditation or MBIs, have been demonstrated via meta-analyses and systematic reviews. Mindfulness meditation has been shown to have a positive impact on cognitive and emotional processing (Tang et al. 2015) and psychological well-being Sedlmeier et al. 2012). MBIs have demonstrated effıcacy in the treatment of a wide range of conditions such as stress, anxiety and depression (Chiesa and Serretti 2009;Khoury et al. 2013), substance abuse (Chiesa and Serretti 2014), chronic pain (Hilton et al. 2017), behavioural addiction (Shonin et al. 2014b), anger and hostile behaviour (Shonin et al. 2013) as well as facilitating adaptive behaviours, such as improved job performance (Van Gordon et al. 2014).
As the beneficial effects of mindfulness training have continued to accumulate over the past decade, a parallel line of enquiry has begun to characterize the underlying mechanisms of mindfulness training (e.g. Brown et al. 2007;Shapiro et al. 2006). These early theoretical models identified psychological processes which were thought to be elicited by mindfulness, such as improved attention regulation and enhanced emotion processing via mechanisms such as decentering (the ability to detach from thoughts and emotions and not perceiving them as accurate representations of self or reality) and nonattachment (not clinging to or rejecting certain aspects of consciousness) (Brown et al. 2007;Shapiro et al. 2006). While these early models of mindfulness were helpful in highlighting important mechanisms, recent theoretical work has attempted to provide more elaborate models. Drawing on a wide range of neurobiological, behavioural and clinical research based on meditationnaïve and experienced practitioner samples from different contemplative traditions, two recent theories stand out due to their extensive review and synthesis of findings into process-based explanatory frameworks. Vago and Silbersweig's (2012) Self-Awareness, self-Regulation and self-Transcendence (S-ART) model builds and extends on a previous neurobiological framework (Hölzel et al. 2011). Drawing on both Western psychology and Buddhist theory, the S-ART model posits that the underlying cause of psychopathology stems from biases related to self-perception and proposes that mindfulness training operates by eliminating these biases (Vago and Silbersweig 2012). Mindfulness is not conceptualized as a unidimensional mental quality but is perceived as a skill, working in harmony with other supporting cognitive skills, such as diligence and perceptual clarity (Vago and Silbersweig 2012). The theory explains how different types of mindfulness meditation may attenuate biases related to metaawareness of self (self-awareness), altering one's automatic response patterns (self-regulation) and enhancing prosocial behaviour (self-transcendence) (Vago and Silbersweig 2012).
According to the S-ART model, mindfulness meditation is purported to operate via the activation of six key sub-mechanisms: (a) intention and motivation which help maintain meditation awareness; (b) regulation of attentional networks for improved processing of self-related information; (c) regulation of experiential, expressive and evaluative processing of emotion; (d) exposure leading to extinction of conditioned maladaptive habits, as well as the cultivation of more adaptive response patterns via memory reconsolidation; (e) prosocial behaviour via increased empathy and perspective-taking; and (f) decentering and nonattachment (Vago and Silbersweig 2012). The S-ART model is primarily concerned with how mindfulness training promotes hedonic well-being (Huta and Waterman 2014), that is, increasing positive affect by reducing psychopathology. However, an alternative theory, known as mindfulness-to-meaning theory (MMT) (Garland et al. 2015), posits a process whereby mindfulness increases not only hedonic but also eudaimonic well-being, which is the capacity to derive more meaning from life (Huta and Waterman 2014). According to MMT, when individuals are faced with aversive or stressful events, mindfulness enables them to decenter from negative emotions and broadens awareness so that additional, nonnegative aspects of their situation can be processed. This broadening of attention facilitates positive reappraisal such that negative experiences are reconstrued as more neutral or benign. Positive reappraisal, in turn, increases positive emotions, and over time, this more positive outlook enables individuals to savour positive experiences and engage more meaningfully with their lives (i.e. leading to eudaimonic well-being) (Garland et al. 2015).
While both the S-ART model (Vago and Silbersweig 2012) and MMT (Garland et al. 2015) offer credible explanations about how mindfulness meditation works, their evidence base has notable limitations. As previously noted, both theories rely on studies based on different meditation practices, ranging from extended practice from different contemplative traditions (e.g. Hanley et al. 2014) to MBIs (e.g. Farb et al. 2007) and brief mindfulness inductions (e.g. Zeidan et al. 2010). Pooling of heterogeneous practices limits conclusions about which techniques lead to certain effects and mechanisms. More specifically, the S-ART model predominantly draws on neurobiological studies which compare nonmeditators to experienced practitioners in terms of brain anatomy and cognitive-affective functioning, without acknowledging how observed changes in meditators may have been influenced by the wider context of practice such as ethics and contemplative teachings (Davidson and Kaszniak 2015;McCown 2013). Furthermore, the Buddhist constructs which have been incorporated into the model-such as perceptual clarity-have a theoretical basis (Buddhaghosa 1991), with no input based on the experiences of practitioners. Similarly, MMT ignores the role of context despite theorising about longer-term effects of mindfulness training, and it also draws heavily on research conducted with meditation-naïve or novice mindfulness meditators (e.g. Garland et al. 2011;Garland et al. 2013). These methodological issues are symptomatic of the wider mindfulness research literature and have been identified as limitations in several reviews (e.g. Davidson and Kaszniak 2015;Van Dam et al. 2018), with calls for more rigor in defining what type of mindfulness training is being studied, with whom and under what circumstances.
Qualitative research conducted with a group of longterm practitioners who adhere to the same style of mindfulness meditation can help address these methodological shortcomings and provide a more in-depth theoretical understanding of the effects and mechanisms of extended mindfulness training. However, such research is scarce and existing qualitative research tends to focus on effects of short-term mindfulness training via MBIs (e.g. Cairns and Murray 2015;Wyatt et al. 2014), long-term meditation based on inadequately specified techniques (e.g. Machado and Costa 2015) or a mix of meditation traditions (e.g. Lomas et al. 2015;Shaner et al. 2017).
A notable exception is a grounded theory study by Hölzel et al. (2006) which recruited experienced meditators who practise VG meditation. Participants reported greater awareness of body sensations, decentering towards emotions and aspects of self, improved psychological functioning, improved social interactions and more acceptance and compassion towards self and others (Hölzel et al. 2006). The strength of this study was investigating a specific type of Vipassana meditation, meaning that the findings from this study can be more conclusively linked to the specific techniques used within this tradition. However, unfortunately, only a summary of the results is available (B. Hölzel, personal communication, January 16, 2017). Consequently, a fuller description of participants' meditation techniques and an in-depth analysis of participants' experiences, evidenced by their own words, are lacking.
The present study aims to extend Hölzel et al.'s (2006) qualitative study in two ways. Firstly, given that systematic reviews of Vipassana meditation (Chiesa 2010;Shonin et al. 2013) indicate that research has predominantly focused on VG meditation, this study investigates a novel group of experienced VM meditation practitioners in order to provide new insights into the effects and mechanisms of extended mindfulness training. Secondly, the present study employs interpretative phenomenological analysis (IPA) (Smith et al. 2009) to conduct a rigorous and systematic analysis of the accounts of particular individuals within a well-defined context, which affords a more in-depth and fine-grained examination of lived experiences compared to other qualitative methods such as grounded theory (Glaser and Strauss 1967). These features render IPA highly suitable for exploring the subjective experience of long-term VM meditation, specifically in terms of how experienced VM practitioners make sense of the effects of their practice, as well as their understanding of how VM elicits these effects.

Method
Participants IPA best-practice guidelines recommend working with samples which have similar characteristics and are small (e.g. three to six participants) so that experiences concerning similar phenomena can be explored and analysed in-depth (Pietkiewicz and Smith 2014;Smith et al. 2009). Based on these guidelines, a purposive selection strategy was followed, aiming to recruit four to six experienced VM practitioners. To ensure that participants adhered to the same meditation style, several Dutch meditation organizations affiliated with the VM tradition were contacted. After obtaining ethical approval and securing written permissions from these organizations, the study was advertised via a letter disseminated through the organizations' teachers, digital newsletters and official Facebook pages. Six participants registered an interest and were sent a participation information sheet. However, one individual declined to participate for personal reasons and the other individual did not pursue their interest any further. Thus, a total of four experienced VM practitioners were recruited into the study.
All participants received a brief questionnaire to screen their eligibility criteria and gather detailed information about their practice. The eligibility criteria were age over 18 years, fluency in English and being experienced in VM meditation. Establishing an individual's meditative proficiency is a complex process (Van Gordon et al. 2018), and there is a lack of standardised criteria for determining meditation experience (Davidson and Kaszniak 2015). Thus, following consultation with a senior VM meditation teacher (who did not participate in the study), the present study deemed an experienced VM meditator to be an individual with (a) at least 5 years of daily VM practice (whether in formal meditation or while engaged in work or other activities), (b) a maximum of 20 years of VM experience (i.e. for the purposes of sample homogeneity), (c) attendance at a minimum of two 10-day-long VM retreats, (d) formal meditation practice at least three times per week and (e) integration of VM into family, work and daily activities. Due to difficulties in finding eligible participants, criteria (a) and (b) were subsequently revised to minimum 5 years of experience. After the screening process, participants were sent an online survey link to obtain informed consent and to collect brief demographic information. Although VM meditation was the participants' keystone practice, all participants also reported practicing metta (loving-kindness) meditation which involves cultivating kindness and compassion towards self and others (Khema 1990). One participant also occasionally practised insight dialogue-an interpersonal form of Vipassana meditation (Kramer et al. 2008).
Participants had accumulated 2220-12,418 h of VM experience, spanning 5-40 years. In line with Lutz et al. (2004), estimates of meditation experience were based on selfreported personal and retreat experience. All four participants (two females; median age = 63) were Dutch (white), had completed higher education equivalent to bachelor's or master's level and worked part-time. One individual indicated Christianity as their religion, and the other participants identified themselves as Buddhist. Owing to the close-knit nature of the VM community in the Netherlands, detailed characteristics of each participant are not presented (i.e. due to the risk of disclosing information that could identify participants).

Procedure
IPA (Smith et al. 2009) was used to explore the participants' subjective experiences. IPA's theoretical foundation is informed by phenomenology, that is, a concern with understanding how individuals who are embodied and situated within a particular context make sense of their experiences in the process of engaging with their lives (Smith et al. 2009). Although IPA prioritises the accounts of participants, the sense-making of individuals is elaborated through the interpretations of the researcher to create new understandings of a phenomenon (Smith et al. 2009). IPA also has an idiographic focus where the researcher adopts a case study approach by immersing themselves in the lifeworld of each participant before moving to the next case (Smith et al. 2009). In line with this theoretical framework, data were collected through one-to-one, face-toface, semistructured interviews. This method allows for flexible data collection whereby the same topics can be covered in a way that is guided by participants' own experiences and preferences (Smith and Osborn 2007). The interview topics were shared with participants ahead of time to help them prepare for the interview. Interviews were conducted in English by the first author who is also a VM practitioner and took place at the participants' home or in private meeting rooms.
The mean duration of interviews was 105 min (SD = 22.99). The interview schedule consisted of open-ended interview questions, exploring general topics such as how participant's started VM meditation and progressively moving to more specific questions related to the research aims, i.e. the perceived effects of VM meditation ('If you think back to when you first started meditating and where you are in your life now, what have been your experiences regarding the effects of VM meditation?') and the perceived mechanisms of VM meditation ('Have you thought about how VM meditation may be leading to these effects? If yes, how do you think it works?'). At the start of the interview, the participants were instructed that although there are specific topics of interest to the researcher, they are free to lead the discussion and talk openly about all experiences, both positive and negative. During the interview, the researcher used additional prompts to enable participants to clarify or elaborate on initial responses (e.g. 'Can you tell me more about that?'; 'How did you feel about that?'). The interviews were audio recorded digitally and transcribed verbatim, capturing all spoken words and nonverbal utterances such as laughter or significant pauses. The names of participants were then anonymised.

Data Analysis
The data were analysed by the first author based on IPA's phenomenological and hermeneutic (interpretative) focus and following the six-step procedure outlined by Smith et al. (2009). First, for each interview, the transcript was read and reread to ensure that the researcher immersed themselves in the lifeworld of the participant. Second, line-by-line exploratory comments were made which took into account both descriptive (i.e. participants' understanding of events or processes) and linguistic (e.g. use of repetition or metaphor) features. Third, these notes provided the basis for generating emergent themes that identified common units of meaning. Fourth, the emergent themes were distilled and organised into higher-order super-ordinate themes. Fifth, in keeping with IPA's idiographic focus, steps 1 to 4 were repeated for each subsequent case. Finally, super-ordinate themes from each interview were compared, contrasted and further organised into a final set of master and subordinate themes. Stages 4 to 6 involved a more iterative and interpretative process, whereby themes were selected, labelled and reorganised. This process was informed by the first author's affinity with VM meditation and knowledge of relevant Buddhist and scientific literature. Themes were supported by participant quotes to demonstrate that the analysis was grounded in the participants' own words. Quotes were selected based on how accurately, vividly and succinctly they represented each master theme.

Reflexivity
Given IPA's hermeneutic focus, it is important to acknowledge how the first author's background may have affected the analysis. As a secular VM meditator, the first author's interest in exploring the lived experience of long-term VM meditation was born out of the need to expand and complement the findings of current mindfulness research, which tend to ignore the impact of Buddhist ethics and teachings on the effects of longterm meditation. Although the first author adhered to the IPA guidelines to set aside their preconceptions during the data collection and initial stages of analysis (Smith et al. 2009), these a priori concerns and experiences may have influenced the final analysis.

Validity
Following IPA guidelines (Smith et al. 2009), an audit was carried out where a second member of the research team examined the interview recordings and annotated transcripts and also the paper trail delineating all the analytical steps to ensure that the themes and subsequent analysis were grounded in the original data and emerged from the participants' accounts in a logical and credible fashion (Flick 2009). Furthermore, respondent validation (Lincoln and Guba 1985) was obtained by sending a summary of the master and subordinate themes to all participants. Two participants were in agreement and had no comments, and feedback from the other two participants was incorporated into the final analysis.

Results
Although the analysis followed an inductive approach, the emergent themes are presented in two sections, in line with the a priori aims of the study. The section BPerceived outcomes^discusses themes related to the perceived effects of VM meditation on participants' lives. The section BPerceived Processes^delineates the key mechanisms participants ascribed to this practice based on their interviews. The final master and subordinate themes are shown in Table 1. Detailed descriptions of each theme, supported by illustrative participant quotes, are presented below.

Perceived Outcomes
From Imbalance to Hedonic and Eudaimonic Well-Being From Distress to Meaning and Purpose in Life Prior to staring VM meditation, all participants reported experiences which could be characterized as a state of 'disbalance' (Peter) due to various life crises. Anna felt spiritually unfulfilled and was looking for 'guidance'. Peter recounted undergoing 'terrible burnout' which led him to give up his career. Similarly, Sophie had been feeling 'exhausted and stressed' and grappling with 'many questions': questions like 'Why am I always tired and other people not?' I even tried to copy other people just to hope that I would feel the same way.
Sophie's apparent wish to replicate others' behaviour suggests a sense of not fitting in with the world and underscoring a need to understand the roots of her impaired functioning. This desire to find answers seems to have had a more pressing relevancy for Peter and Tim who were questioning their very existence. Peter spoke of feeling 'life has no use for me anymore'. Likewise, Tim reported experiencing low mood and anxiety and searching for a way to give his life meaning and purpose: I could not see anything for me here [Holland] … I have to find something to make this life worthwhile. Because I was really thinking this life is not for me.
This quest for 'something' eventually led participants to VM meditation where they all reported feeling an intuitive connection to the practice. Peter spoke about a eureka moment where he instinctively thought 'Yes this is it' upon first trying out VM meditation. This initial positive experience led him to make a cascade of life changes in work, personal and spiritual domains, eventually resulting in an increased sense of 'rest' and 'peacefulness'. Similarly, trying VM meditation had a life-changing impact for Tim: that was my first retreat. And I felt like coming home … I knew, directly, I knew with all my, with all I am, that this was it.
The phrase 'coming home' evokes both positive feelings such as warmth and security, as well as attaining a sense of belonging. The retreat experience seems to have signalled an end to Tim's search for meaning, enabling him to attain a sense of well-being and re-engage with a life which he had left behind: 'I'm happy, it's ok, I can go back'.
These extracts indicate that VM meditation served as a gateway through which participants were able to achieve both hedonic and eudaimonic well-being. The beneficial effects of mindfulness meditation have most consistently been linked to improved hedonic well-being in both quantitative  and qualitative (Hölzel et al. 2006;Machado and Costa 2015) studies. The link between mindfulness meditation and eudaimonic well-being has received less empirical attention (Garland et al. 2015). Nevertheless, the present findings are in line with a qualitative study reporting that longterm mindfulness meditators feel fully engaged with their lives (Machado and Costa 2015).

Importance of Buddhist Ethical Practices
Unlike the aforementioned study by Machado and Costa (2015), participants of the present study did not just attribute these positive outcomes to meditation: It's not only practicing Vipassana but try to, to follow the noble eightfold path, the Buddhist road. (Peter) The mindfulness, the wisdom. Not alone, not alone, it's a combination. Also, the ethics, because you cannot be mindful and you will not get a mind who is quiet.
Here, both Peter and Anna are referring to the supporting role of the Buddhist eightfold path-a system of attitudes and behaviours which must be adopted to eliminate habitual response patterns deemed 'unwholesome' or maladaptive according to Buddhist metaphysics and morality (Huxter 2015). Interestingly, this supportive role of ethics was also acknowledged by Sophie who did not identify herself as a Buddhist: I'm trying … to keep this sila [ethical conduct], the five precepts, I try to keep them as much as possible… Sophie perceived these precepts or ethical behaviours as a means to 'protect' herself from engaging in behaviours which could have harmful consequences for her and others. It seems that through VM meditation, participants cultivated a new values system which may have also contributed to the reported improvements in eudaimonic well-being. Indeed, having and wanting to serve a higher purpose in life and living a life in accordance with deeply held values constitute key aspects of eudaimonia (Huta 2015). This theme supports the main theoretical thrust of both the S-ART model (focusing on hedonia) (Vago and Silbersweig 2012) and MMT (focusing on eudaimonia) (Garland et al. 2015). However, it goes further by demonstrating that the broader philosophical, spiritual and ethical context of mindfulness meditation also makes an important contribution to well-being.

'See things clearly': Insights into Self and Beyond
This theme describes the different types of insights participants reported gaining through VM meditation.
Insight into Mind-Body Interaction It appears that the initial effects of VM meditation involved a greater understanding of habitual, and often negative, cognitions and corresponding physical sensations: the body is also-during meditation-a very good instrument to be aware of stress. Because … when there is stress in your mind, [there is] also a reaction in your body … when I feel some stress in my forehead, at first, I saw that as 'Ah, that's thinking'. Because often when there is analyzing and clinging, keeping control of things, the tension in my forehead arises. (Peter) Peter's extract suggests that the body functions like an early warning system for signalling oncoming emotions. Similarly, Tim referred to being able to gauge the state of his mind by observing his breath during meditation: in rising falling [of the abdomen] you can read your situation. … the subtlety of your perception … the friction or the absence of friction. This increased empathy for his father subsequently led to compassionate feelings including 'softness and warmth around my heart', giving Peter 'another view' of his estranged father. Sophie also recounted experiencing a similar feeling:

Insight into Mind States of Others
when I started meditating … it's incredible because that second time and the third course, I saw the things Although these subordinate themes are in line with previous qualitative findings (Hölzel et al. 2006;Machado and Costa 2015), the extracts here make a clearer link to insights arising during the physical act of meditation. Furthermore, Peter's repetitive use of 'Ah' in both extracts to preface his insights suggests that these insights were experienced spontaneously, an interpretation made more plausible by Sophie's remark: 'suddenly the answer is there or you see things clearly'.
Insight into the Nature of Reality The more advanced practitioners, in particular, talked about experiencing insights relating to the true nature of reality according to Buddhism, that is, the realization that all things are unsatisfactory, impermanent and devoid of intrinsic existence (Harvey 2015) This sense of a diminished self has been found in other studies with advanced mindfulness practitioners (e.g. Dor-Ziderman et al. 2013). One explanation for this shift in self-perspective is provided by the S-ART model (Vago and Silbersweig 2012) that claims mindfulness meditation promotes a shift from a more autobiographical and evaluative self-referential state to one that is more experiential and present focused (Brewer et al. 2011;Farb et al. 2007).
It is important to note that the experience of nonself might be construed as pathological by Western psychological standards (Dor-Ziderman et al. 2013;Fulton and Siegel 2005). However, the fact that such a characterization did not come across in participants' accounts may be because they made sense of these experiences in light of Buddhist teachings, which consider such transcendental insights to be a sign of spiritual progress (Mahasi 2016).

From Imbalance to Balance: Attaining Equanimity
As the previous themes have shown, VM meditation and related practices resulted in increases in both hedonic and eudaimonic well-being. However, the accounts of participants revealed another type of well-being which seems to transcend these categories. Participants characterized it as a sense of 'inner peace' (Anna) and 'a sense of well-being you've never experienced' (Tim) stemming from an even-minded mental state that embraces all experiences equally: So, equanimity for me is that you stay more neutral, you can go back easier, you just acknowledge 'Ok, if it's, whatever is there, the anger, the fear, the joy', but so there is less, less and less reaction. (Sophie) Although Sophie understood the meaning of equanimity conceptually, she added: 'I'm far from it', suggesting that this quality needs to develop over time to be experienced more continuously. Anna's characterization of acceptance as 'too active' suggests that equanimity initially has an active aspect to it, which over time transforms into a more passive 'let it be' mode. This dual characterization of equanimity as both a volitional state or attitude and a more enduring, trait-like quality is in line with elucidations by Desbordes et al. (2015). Another noteworthy aspect of Anna's excerpt is the association of equanimity with 'wisdom.' The following quote from Tim sheds light on this connection: Equanimity … can easily be misunderstood, huh? … That it's just some mind state … that you like, and you're staying there … but … this changes, also. But if you [stay] in this … mind state of contentment even when everything is changing … the whole world can fall apart and then you're still sitting there.
This extract conjures up a powerful image of stability and continuity amidst chaos, suggesting that equanimity is not simply a transient pleasant emotional state, but a more enduring quality of mind which emerges with more advanced practice, enabling the practitioner to discern impermanence-a characteristic of 'ultimate reality' and therefore, wisdom (Mahasi 2016). Although previous qualitative studies report that mindfulness helped participants experience greater equanimity in everyday life (Machado and Costa 2015), the present findings offer a more dynamic, nuanced and experiential characterization of this construct as well as its relationship to Buddhist wisdom. Furthermore, participants' experiences of equanimity also appear to reflect undertones of sukha, a Buddhist notion referring to a long-lasting Bstate of flourishing that arises from mental balance and insight into the nature of reality^ (Ekman et al. 2005, p. 60).

Physical and Interpersonal Challenges
In addition to the more positive consequences of VM meditation outlined so far, participants also recounted experiencing difficulties. One such issue related to the physical difficulties experienced during extended periods of formal meditation, particularly with respect to pain: all this physical pain; as I did sitting meditation and … walking meditation. So, in the moment I thought 'I, I can't handle this … I should go home. This is too much'.
Nevertheless, participants reported being able to gradually overcome these physical difficulties by learning to remain aware of and accept pain (i.e. via the aforementioned process of decentering and nonattachment). However, VM meditation also resulted in more persistent, interpersonal difficulties. Negative experiences related to meditation practice is an underresearched topic, with studies thus far tending to focus on adverse effects such as psychosis (Hanley et al. 2016) as well as impaired memory functioning, narcissism and reality testing (Van Gordon et al. 2017a). Studies on the interpersonal effects of mindfulness meditation are also scarce (Creswell 2017), with most studies reporting positive associations (e.g. Hölzel et al. 2006;Machado and Costa 2015). This previously observed positive association is consistent with the finding in this study that participants experienced improved paternal relationships as a result of VM practice. However, similar interpersonal conflicts to those identified in this study have also been reported in a previous study with long-term Vipassana meditators (Shapiro 1992), suggesting that the link between mindfulness meditation and interpersonal outcomes is more complex than what current theoretical models and studies indicate.

Perceived Processes
This section presents themes related to how participants made sense of the mechanisms of VM meditation. For Peter, the process of purification appears to have started with awareness. This was corroborated by other participants' accounts: 'that is the first step' (Sophie); 'It is … because of the mindfulness, I think.' (Anna). The onion analogy further suggests that this is an ongoing process whereby unhelpful mental habits are progressively peeled away. Peter's mention of 'body, feelings, mind, and the dhammas [specific contemplative frameworks based on the teachings of the Buddha (Analayo 2003)]' refers to the four main categories of objects which Vipassana meditators must contemplate according to the Satipatthana sutta-a seminal Buddhist discourse on how to establish mindfulness (Analayo 2003). This indicates that Peter's understanding of the mechanisms of VM meditation was influenced by these Buddhist teachings.
The Satipatthana sutta further describes how mindfulness does not operate in isolation but is supported by several other mental qualities, such as effort and diligence as well as clear knowing and freedom from desire (Analayo 2003). This multicomponent characterization of mindfulness is also expressed in account of Tim who explained that 'what normally is thought to be mindfulness is actually a cooperation between a lot of other qualities, … [including] the right energy [and] the right concentration'. Right energy or effort is needed so that the meditator does not experience mental agitation, or at the opposite spectrum, 'fall asleep' (Tim), whereas concentration enables 'a mind who is quiet', so that 'wisdom' can arise (Anna).
A further quality that participants linked to mindfulness is sampajano, which is related to the Pali word, sampajanna, meaning clear knowing (Analayo 2003) or clear comprehension (Harvey 2015): mindfulness … in the Vipassana tradition goes always together with sampajano … that is wisdom.' (Anna) According to Tim, 'this knowing, this understanding' initially consists of discerning clearly what is happening at any one moment, such as noticing the tactile sensations during breathing (e.g. 'this is the breath going in and pushing the belly out'). However, as the practice develops further, the meditator's perception of reality changes: And then, there's still knowing, but there are no more concepts … [and you become aware of] the natural existence of feelings that are not yours or they are not your invention, but they are there just there and that's when you come in touch with the tension, and, relaxation and hardness, and softness-these are the building blocks of every sensation. And then there's one step [beyond] that and that you start to see … all these different sensations that you feel … they are changing, changing, changing … [the] only binding characteristic is change.
According to Tim, the nature of sampajanna changes over time, allowing the practitioner to discern the flow of experience in a more differentiated way, which subsequently leads to the direct experience of impermanence, or as Anna expressed it 'wisdom'. The experiences of Tim and Anna, who relatively have more experience than the other participants, appear to be in line with Buddhist teachings that recognise the dynamic and evolving nature of sampajanna along with its role in facilitating wisdom (Analayo 2003;Bodhi 2005). However, sampajanna and other supporting mental qualities have not been subject to in-depth empirically analysis meaning that when they are included in theoretical models such as the S-ART model (Vago and Silbersweig 2012), their role in facilitating deeper insights or wisdom remains unclear.
Decentering and Nonattachment This theme related to how VM meditation helped participants to change their usual responses to mental and emotional events. Peter expressed this process as not clinging to emotions: 'let them go, not keeping them', whereas Anna expressed it as to learning 'to surrender' to pain. Sophie talked about not getting caught up in her thoughts: Vipassana is like a tool for me to observe the mind, not to go in my thoughts anymore … I think I had a really sticky mind [such] that whatever would pass, I would see it as truth … [but] … now I can recognize it 'Oh, there is this, again, hello!' and I just go back [to] doing the dishes or whatever I'm doing.
It appears that through VM meditation, Sophie was able to reduce her ruminative tendencies, leading her to respond more adaptively. For Tim, the process involved recognising and 'unlearning' the tendency to crave positive and reject negative experiences: Yeah, it has to do with this wanting and not wanting. And, so this is something that creates your pain. But it is something that you have acquired. It's something you have learned. And so, you can unlearn it. And, this is what you do by standing still, being with whatever happens and then, you don't react … you disarm it. You make it functionless and that means that you gradually … abandon this wanting and not wanting.
These participant excerpts appear to illustrate several closely related processes-such as decentering and nonattachment-that are outlined in extant theoretical models. For example, Tim's reference to how nonattachment gradually leads to the unlearning of maladaptive habits is similar to the process of exposure and extinction that is explicated in the S-ART model (Vago and Silbersweig 2012). However, for Tim, the process extends well beyond behaviour change: And this wanting and not wanting creates, unrest, creates anxiety … And all this anxiety and unrest, that slowly diminishes. And then in this calm … you go even deeper, you find more of this friction, you find more unrest. You also bring that to calm and then go on and on and on and on and on. And then, this equanimity becomes very strong. And, you can go even deeper by going into this ever-changing nature of everything that happens.
Tim's extract suggests that decentering and nonattachment do not end with mental calm and the alleviation of negative affect but trigger multiple iterations of identifying and uprooting maladaptive habits, which eventually lead to increased equanimity and wisdom. Tim's abovementioned account diverges from the pathway proposed in MMT (Garland et al. 2015), whereby decentering is posited to facilitate positive reappraisal and positive affect, rather than nonattachment and equanimity. This discrepancy might be due to the different emotion regulation strategies used by novice and experienced meditators. For example, recent reviews of neurobiological studies have indicated that inexperienced meditators are more likely to use effortful emotion regulation strategies, such as reappraisal, whereas experienced meditators rely more on implicit or automatic emotion regulation (Chiesa et al. 2013;Guendelman et al. 2017). This type of effortless bottom-up processing (Chiesa et al. 2013) accords with how the current sample of participants, particularly Anna and Tim, who are more experienced practitioners, characterized and described equanimity. Consequently, these findings suggest that theories such as MMT (Garland et al. 2015) also need to incorporate a bottom-up emotion regulation pathway to reflect more advanced stages of mindfulness practice.

Discussion
This qualitative IPA study explored how experienced Vipassana Mahasi (VM) practitioners make sense of the effects of meditation on their lives and what processes they attribute to producing these outcomes. The in-depth and rich accounts of participants yielded four overarching themes related to perceived effects of meditation: (a) improvements in hedonic and eudaimonic well-being; (b) insights into self, others and perception of reality; (c) attaining equanimity; and (d) physical and interpersonal difficulties. Regarding the perceived mechanisms of meditation, participants regarded VM meditation as a 'cleansing process' whereby maladaptive mental habits were gradually reduced by means of (a) mindfulness and supporting mental qualities and (b) decentering and nonattachment.
Participants initially started VM meditation to manage psychological distress related to a lack of meaning and purpose in their lives. However, through cultivating mindfulness and nonattachment, participants reported gaining a greater awareness and understanding of their own and others' mental states, which led to reduced distress, increased positive affect, increased equanimity and improved psychological functioning. Starting VM meditation also led participants to integrate Buddhist teachings and practices into their lives. This appeared to enable them to engage more meaningfully with life and deepen their meditation practice, which resulted in shifts in perspective as to how they viewed reality. Through continued practice, this shift in perspective and increase in meditative wisdom enabled participants to experience life events with more equanimity. Greater equanimity, in turn, was perceived as inducing deeper states of calm and leading to further spirals of wisdom, equanimity and well-being.
A number of these outcomes and processes have been identified in previous research and theoretical models. The present findings, informed in particular by the accounts of more advanced practitioners, reveal more complex and dynamic patterns of interrelated processes, shaped by the broader Buddhist context for meditative and spiritual development. Indeed, unlike other studies, the present findings suggest that the states of well-being experienced by advanced VM practitioners transcend hedonia and eudaimonia. Furthermore, participants' narratives provide a more nuanced understanding of long-term VM meditation, indicating that this is a physically and emotionally challenging practice that can produce both positive and negative interpersonal outcomes.
Findings from this study point to several novel areas that require further investigation and which may inform future theoretical work. In particular, it is currently unclear how VM meditation gives rise to insights into the nature of self and reality. It has been suggested that there may be an association between the insights elicited by some forms of mindfulness meditation and the 'aha' moment that characterizes insight problem-solving (Dahl et al. 2015;Lebuda et al. 2016). Similarly, IPA studies of an intervention known as Meditation Awareness Training suggest that insight arises as participants use mindful awareness to try to locate the 'selfness' of either themselves or of phenomena more generally Van Gordon et al. 2016). Since this 'selfness' cannot be found during meditative investigation, the practitioner gradually realizes they are empty of inherent existence. However, more work is needed to elucidate how insights arise during embodied VM practice and what role knowledge of the Buddhist teachings plays in this process.
Findings from this study also highlight a number of Buddhist constructs which may benefit from novel conceptualizations and/ or recontextualization (i.e. to be compatible with modern Western scientific modes of thinking) so that the mechanisms of mindfulness can be understood more fully. These constructs include mental qualities such as sampajanna, which are deemed to complement mindfulness, and enduring states of well-being such as equanimity and sukha. Capturing the complexity and dynamism of these constructs is likely to be challenging, due to their subjective and opaque nature . Nevertheless, some preliminary efforts have begun, as exemplified by a recent study that has attempted to operationalize and measure equanimity in novice meditators (Hadash et al. 2016).
Given that Buddhist teachings and ethical practices featured heavily in how participants perceived the outcomes and processes of meditation, it may be worthwhile to investigate how provision of such teachings may help participants of MBI programs better understand these meditation techniques as well as integrate them more fully into their lives. This additional context may be more appropriate for participants who are experiencing existential distress and are more receptive to spiritual development. It is encouraging to see that researchers and clinicians have already begun to incorporate Buddhist philosophy and teachings into existing interventions and therapies in a manner that is accessible to a secular, lay audience (Monteiro 2015;Tirch et al. 2015). These approaches correspond to what have been termed the 'second-generation of mindfulness-based interventions' (SG-MBIs)  and new SG-MBIs such as Meditation Awareness Training (MAT) (Van Gordon et al. 2017b), which have recently been tested in clinical trials, with promising results (e.g. Shonin et al. 2014a;Van Gordon et al. 2017b). However, more work is required to understand in what context and for whom SG-MBIs may yield the best outcomes.
A key finding from this study was that extended VM meditation can lead to challenges in the interpersonal domain. It is reasonable to assume that challenges are associated with the diligent practice of any form of Buddhist meditation and are not necessarily detrimental in terms of the practitioner's longterm meditative development. However, more research is required to understand the scope of such experiences and under what circumstances they arise.

Limitations and Future Research
In line with IPA's idiographic focus, the findings from this study are limited to the experienced VM meditators practicing within a Western (Dutch) context and may not generalize to other VM practitioners or experienced meditators following other Buddhist traditions. However, results aggregated from future IPA studies on experienced mindfulness meditators may eventually allow researchers to claim more universal outcomes and mechanisms of action (Smith et al. 2009). Although VM meditation was participants' primary form of meditation practice, it is clear that the perceived effects and outcomes were also influenced by Buddhist teachings and ethical practices, including metta meditation (Mooneyham et al. 2016). Thus, it is not possible to attribute these outcomes solely to VM meditation. Nevertheless, the experiences of participants are consistent with outcomes and processes ascribed to Vipassana meditation in Buddhist scriptures, which strengthens the conclusion that these findings may be linked to VM meditation. Finally, the present study sample varied considerably in terms of years of meditation practice and ensuring more homogeneity regarding meditation experience remains a challenge for future mindfulness researchers. Nevertheless, this discrepancy also yielded valuable insights into how increased meditation experience may lead to more sophisticated understandings regarding the outcomes and mechanisms of long-term VM practice.
The present study indicated that future research can benefit from investigating emergence of insights during meditation, operationalization of novel Buddhist constructs, integration of ethics and Buddhist teachings into MBIs and examining adverse interpersonal effects of long-term meditation. Research into these topics will require further collaboration between Western contemplative scientists, Buddhist scholars and meditation practitioners. Such work would also necessitate studies of a longitudinal nature, using novel theoretical and methodological approaches. For example, neurophenomenological studies which combine first-person perspectives with neuroscientific methods (e.g. Dor-Ziderman et al. 2013) offer an innovative and reliable manner for capturing the subjective experiences of meditators. Likewise, a novel paradigm known as embodied cognition, which acknowledges the role of body processes in shaping cognition (Shapiro 2010), may provide a more comprehensive understanding of an inherently embodied practice such as VM meditation.
Author Contributions ÇE was the researcher, conceived of and designed the study, conducted the data analysis and wrote the first draft of the paper. GG supervised and collaborated in the conceiving of and design of the study and on the writing and editing of the final manuscript. WVG collaborated in the writing and editing of the final manuscript. All authors approved the final version of the manuscript for submission.

Compliance with Ethical Standards
Conflict of Interest The authors declare that they have no conflict of interest.
Ethical Approval All procedures performed in studies involving human participants were in accordance with the ethical standards of the University of Derby Research Ethics Committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.
Informed Consent Informed consent was obtained from all individual participants included in the study.