How Does Mindfulness Meditation Work? Proposing Mechanisms of Action From a Conceptual and Neural Perspective - Keys To Success
←
→
Page content transcription
If your browser does not render page correctly, please read the page content below
Perspectives on Psychological Science
How Does Mindfulness Meditation Work? 6(6) 537–559
© The Author(s) 2011
Reprints and permission:
Proposing Mechanisms of Action From a sagepub.com/journalsPermissions.nav
DOI: 10.1177/1745691611419671
Conceptual and Neural Perspective http://pps.sagepub.com
Britta K. Hölzel1,2, Sara W. Lazar2,Tim Gard1,2,
Zev Schuman-Olivier2, David R.Vago3, and Ulrich Ott1
1
Bender Institute of Neuroimaging, Justus Liebig-University, Giessen, Germany; 2Massachusetts General Hospital,
Harvard Medical School, Boston, MA; and 3Brigham and Women’s Hospital, Harvard Medical School, Boston, MA
Abstract
Cultivation of mindfulness, the nonjudgmental awareness of experiences in the present moment, produces beneficial effects on
well-being and ameliorates psychiatric and stress-related symptoms. Mindfulness meditation has therefore increasingly been
incorporated into psychotherapeutic interventions. Although the number of publications in the field has sharply increased
over the last two decades, there is a paucity of theoretical reviews that integrate the existing literature into a comprehensive
theoretical framework. In this article, we explore several components through which mindfulness meditation exerts its
effects: (a) attention regulation, (b) body awareness, (c) emotion regulation (including reappraisal and exposure, extinction,
and reconsolidation), and (d) change in perspective on the self. Recent empirical research, including practitioners’ self-reports
and experimental data, provides evidence supporting these mechanisms. Functional and structural neuroimaging studies have
begun to explore the neuroscientific processes underlying these components. Evidence suggests that mindfulness practice is
associated with neuroplastic changes in the anterior cingulate cortex, insula, temporo-parietal junction, fronto-limbic network,
and default mode network structures.The authors suggest that the mechanisms described here work synergistically, establishing
a process of enhanced self-regulation. Differentiating between these components seems useful to guide future basic research
and to specifically target areas of development in the treatment of psychological disorders.
Keywords
anxiety disorders, attention, cognition, consciousness, neuroscience, positive psychology, stress disorders
Mindfulness meditation has been reported to produce beneficial treatment of disorders and improvement of health; it has also
effects on a number of psychiatric, functional somatic, and been shown to produce positive effects on psychological well-
stress-related symptoms and has therefore increasingly been being in healthy participants (Carmody & Baer, 2008; Chiesa &
incorporated into psychotherapeutic programs (cf., Baer, 2003; Serretti, 2009) and to enhance cognitive functioning (Jha,
Grossman, Niemann, Schmidt, & Walach, 2004). A large body Krompinger, & Baime, 2007; Ortner, Kilner, & Zelazo, 2007;
of research documents the efficacy of mindfulness-based inter- Pagnoni & Cekic, 2007; Slagter et al., 2007). Historically, mind-
ventions in the treatment of a number of clinical disorders, fulness is a concept stemming from ancient Buddhist philoso-
including anxiety (Hofmann, Sawyer, Witt, & Oh, 2010; phy (Bhikkhu, 2010), and is practiced to achieve enduring
Roemer, Orsillo, & Salters-Pedneault, 2008), depression (Hof- happiness (Ekman, Davidson, Ricard, & Wallace, 2005) and to
mann et al., 2010; Teasdale et al., 2000), substance abuse gain insight into a view of the true nature of existence (Olen-
(Bowen et al., 2006), eating disorders (Tapper et al., 2009), and dzki, 2010).
chronic pain (Grossman, Tiefenthaler-Gilmer, Raysz, & Kesper,
2007). Furthermore, mindfulness meditation positively influ-
ences aspects of physical health, including improved immune
function (Carlson, Speca, Faris, & Patel, 2007; Davidson et al.,
Corresponding Author:
2003), reduced blood pressure and cortisol levels (Carlson et al., Britta K. Hölzel, Bender Institute of Neuroimaging, Justus Liebig-University,
2007), and increased telomerase activity1 (Jacobs et al., 2010). Otto-Behaghel-Str. 10 H, 35394 Giessen, Germany
Not only has mindfulness successfully been used in the E-mail: britta@nmr.mgh.harvard.edu538 Hölzel et al.
Table 1. Previous Theoretical Accounts That Describe Mechanisms of Mindfulness Meditation
Publication Suggested components
Shapiro, Carlson, Astin, and Freedman (2006) Attention, intention, attitude
Brown, Ryan, and Creswell (2007) Insight, exposure, nonattachment, enhanced mind–body functioning,
integrated functioning
Baer (2003) Exposure, cognitive change, self-management, relaxation, acceptance
Five Facet Mindfulness Questionnaire (Baer, Smith, Hopkins, Observing, describing, acting with awareness, nonjudging of inner
Krietemeyer, & Toney, 2006) experience, nonreactivity to inner experience
Definition of Mindfulness including (a) insight, (b) exposure, (c) nonattachment, (d)
enhanced mind–body functioning, and (e) integrated function-
In current research contexts, mindfulness is typically defined ing. Similarly, in her 2003 review, Ruth Baer summarized sev-
as nonjudgmental attention to experiences in the present eral mechanisms that may explain how mindfulness skills can
moment (Kabat-Zinn, 1990). Bishop et al. (2004) suggest a lead to symptom reduction and behavior change, namely (a)
two-component model of mindfulness, where the first compo- exposure, (b) cognitive change, (c) self-management, (d)
nent is the regulation of attention in order to maintain it on the relaxation, and (e) acceptance. A valuable empirical account
immediate experience, and the second component involves for the description of the facets of mindfulness is the Five
approaching one’s experiences with an orientation of curiosity, Facet Mindfulness Questionnaire (Baer, Smith, Hopkins, Kri-
openness, and acceptance, regardless of their valence and etemeyer, & Toney, 2006), which was developed based on an
desirability. Mindfulness is typically cultivated in formal med- item pool of previously existing mindfulness questionnaires.
itation practices, such as sitting meditation, walking medita- Factor analyses over these items yielded five facets of mind-
tion, or mindful movements (Kabat-Zinn, 1990). The practice fulness: observing (attending to or noticing internal and exter-
of mindfulness meditation encompasses focusing attention on nal stimuli, such as sensations, emotions, cognitions, sights,
the experience of thoughts, emotions, and body sensations, sounds, and smells); describing (noting or mentally labeling
simply observing them as they arise and pass away. these stimuli with words); acting with awareness (attending to
one’s current actions, as opposed to behaving automatically or
absentmindedly); nonjudging of inner experience (refraining
Need for a Theoretical Framework from evaluation of one’s sensations, cognitions, and emo-
It is striking that this seemingly simplistic practice can have tions); and nonreactivity to inner experience (allowing
such a wide range of applications and effects. Along with the thoughts and feelings to come and go, without attention get-
many positive implications of mindfulness arises the question: ting caught in them).
How does mindfulness work; what are its mechanisms? The field has produced a number of studies utilizing psycho-
Although there is currently a large body of literature, covering logical scales or behavioral tasks that provide empirical support
a wide range of research, including qualitative research, feasi- for some of the proposed components. Simultaneously, a grow-
bility trials, controlled clinical trials, behavioral studies, and ing body of neuroimaging literature begins to describe brain
neuroscientific research, there is a relative paucity of theoreti- activity during the meditative state as well as changes in neural
cal reviews that consolidate the existing literature into a com- structure and function associated with meditation practice. To
prehensive theoretical framework. our knowledge, no one has previously tried to consolidate the
Existing research on mindfulness includes a few theoretical existing empirical literature. Our goal is to consolidate existing
accounts describing mechanisms of mindfulness meditation findings and address several components that have been empiri-
(see Table 1). Several of these accounts expound on the central cally supported. Furthermore, whereas the previous models
role of attention in meditation practice (Brown & Ryan, 2003; have described the process of mindfulness almost exclusively
Carmody, 2009; Lutz, Slagter, Dunne, & Davidson, 2008). from a conceptual, psychological perspective, this present
Others have suggested that several components mediate the review will also integrate a neuroscientific perspective. This
beneficial effects of mindfulness practice. For instance, Shap- review is meant not as a complete description of the research in
iro, Carlson, Astin, and Freedman (2006) posit that attention, the field but to stimulate scientific debate.
intention, and attitude are the three critical components of In this review, we first describe what we believe to be the
mindfulness. Intentionally paying attention with a nonjudg- components of mindfulness meditation. We then discuss how
mental attitude leads to a significant change in perspective, a these components are integrated during mindfulness medita-
so-called decentering (Fresco et al., 2007) or reperceiving. tion and suggest how they might interact with each other dur-
Brown, Ryan, and Creswell (2007) also describe several pro- ing a given situation. Finally, the relationship of self-compassion
cesses underlying the beneficial effects of mindfulness, with the components is addressed.How Does Mindfulness Meditation Work? 539
Table 2. Components Proposed to Describe the Mechanisms Through Which Mindfulness Works
Self-reported and experimental
Mechanism Exemplary instructions behavioral findings Associated brain areas
1. Attention regulation Sustaining attention on the Enhanced performance: executive Anterior cingulate cortex
chosen object; whenever attention (Attention Network
distracted, returning attention Test and Stroop interference),
to the object orienting, alerting, diminished
attentional blink effect
2. Body awareness Focus is usually an object of Increased scores on the Observe Insula, temporo-parietal
internal experience: sensory subscale of the Five Facet Mind- junction
experiences of breathing, fulness Questionnaire; narrative
emotions, or other body self-reports of enhanced body
sensations awareness
3.1 Emotion regulation: Approaching ongoing emotional Increases in positive reappraisal (Dorsal) prefrontal cortex
reappraisal reactions in a different way (Cognitive Emotion Regulation (PFC)
(nonjudgmentally, with ac- Questionnaire)
ceptance)
3.2 Emotion regulation: Exposing oneself to whatever is Increases in nonreactivity to inner Ventro-medial PFC,
exposure, extinction, and present in the field of aware- experiences (Five Facet Mind- hippocampus, amygdala
reconsolidation ness; letting oneself be affected fulness Questionnaire)
by it; refraining from internal
reactivity
4. Change in perspective on Detachment from identification Self-reported changes in self-con- Medial PFC, posterior
the self with a static sense of self cept (Tennessee Self-Concept cingulate cortex, insula,
Scale, Temperament and Char- temporo-parietal
acter Inventory) junction
Components of Mindfulness Meditation the Theravada Buddhist tradition [Hart, 1987]; samatha in
Tibetan Buddhist traditions [Lutz, Dunne, & Davidson, 2007];
We believe that an array of distinct but interacting mechanisms or dharana in Indian Yoga traditions [Vishnu Devananda,
are at play in producing the benefits of mindfulness meditation 1999]). They often recommend a focused attention meditation
practice and propose that the combination of the following before moving on to other types of meditations later in the
components—some of which have been identified in previous learning process, such as those that focus on cultivating posi-
accounts—describe much of the mechanism of action through tive emotions. In focused attention meditation ( HYPERLINK
which mindfulness works: "" \l "bib148" \o "bib148" Lutz, Slagter, et al., 2008), attention
is supposed to rest on a single object. Whenever the practitio-
1. Attention regulation ner notices that the mind has wandered off, she or he returns it
2. Body awareness to the chosen object. A typical instruction for a focused atten-
3. Emotion regulation, including tion meditation in the mindfulness meditation tradition is the
a. Reappraisal following: “Focus your entire attention on your incoming and
b. Exposure, extinction, and reconsolidation outgoing breath. Try to sustain your attention there without
4. Change in perspective on the self distraction. If you get distracted, calmly return your attention
to the breath and start again” (Smith & Novak, 2003; p.77).
These components interact closely to constitute a process Illustrating the effects of repeated practice of focused attention
of enhanced self-regulation (Carver & Scheier, 2011; Vohs & meditation, meditators report that the regular practice enables
Baumeister, 2004). However, the different components might them to focus their attention for an extended period of time
come into play to varying degrees within any specific moment (Barinaga, 2003), and distractions disturb this focus less fre-
during mindfulness meditation. In the following sections, we quently during formal meditation practice and in everyday
address each of these components individually (see Table 2 for life. In accordance with such self-reports, a number of studies
a list of the components and their characteristics). have empirically documented enhanced attentional perfor-
mance in meditators (e.g., Jha et al., 2007; Slagter et al., 2007;
Valentine & Sweet, 1999; van den Hurk, Giommi, Gielen,
1. Attention regulation Speckens, & Barendregt, 2010).
Many meditation traditions emphasize the necessity to culti- Behavioral findings on meditation and executive attention. Dur-
vate attention regulation early in the practice (e.g., samadhi in ing focused attention meditation, distracting external events as540 Hölzel et al.
well as memories or thoughts about future events represent con- identified when individuals engaged in a mindfulness prac-
flicts to task goals. These are disregarded while the practitioner tice while awaiting unpleasant electric stimulation (Gard
concentrates on the meditative object (e.g., the breath, body sen- et al., 2010). Five days of Integrative Body–Mind Training
sations, thoughts, emotions, a mantra, or visualization). Main- may lead to greater activation of the rostral ACC during the
taining the focus of attention on a pursued object, while resting state (Tang et al., 2009). Although ACC activation
disregarding distractions, is referred to as conflict monitoring, might initially be enhanced when acquiring greater atten-
or executive attention, and is one of the three attention networks tional control, it might later decrease with higher levels of
proposed by Posner and Petersen (1990). One cognitive test that expertise, when the focus of attention is so steady that moni-
specifically measures executive attention is the executive atten- toring distractions becomes superfluous (Brefczynski-Lewis,
tion task of the Attention Network Test (Fan, McCandliss, Som- Lutz, Schaefer, Levinson, & Davidson, 2007). In addition to
mer, Raz, & Posner, 2002). Two studies found that experienced these functional findings, structural MRI data also indicate
meditators showed better performance on this executive atten- that meditation practice might exert an influence on the ACC.
tion task when compared with nonmeditators, as indicated by Cortical thickness in the dorsal ACC was greater in experi-
smaller error scores (Jha et al., 2007; van den Hurk et al., 2010) enced meditators compared with control subjects in an analy-
and lower reaction times (Jha et al., 2007). Additionally, a lon- sis of brain gray matter (Grant, Courtemanche, Duerden,
gitudinal study showed that only five days of meditation prac- Duncan, & Rainville, 2010), and 11 hr of Integrative Body–
tice (Integrative Body–Mind Training) led to improvements on Mind Training led to an increase in white matter integrity in
this test (Tang et al., 2007). Findings of the influence of mind- the ACC (Tang et al., 2010). In line with the assumption that
fulness practice on executive attention using the classical Stroop ACC function is strengthened through concentrative medita-
task (Stroop, 1935) are mixed. Whereas one study did not find tion, electroencephalogram data document increased frontal
effects of an 8-week Mindfulness-Based Stress Reduction midline theta rhythm during meditation (Aftanas & Golo-
course on Stroop interference (Anderson, Lau, Segal, & Bishop, cheikine, 2002; Kubota et al., 2001). Frontal midline theta is
2007), others using this test found lower Stroop interference in associated with attention demanding tasks and presumably
experienced meditators compared with controls (Chan & Wool- reflects ACC (and medial prefrontal cortex) activity (Asada,
lacott, 2007; Moore & Malinowski, 2009) and a reduction in Fukuda, Tsunoda, Yamaguchi, & Tonoike, 1999).
Stroop interference following a brief meditation intervention Clinical relevance. The strengthening of attention regulation
(Wenk-Sormaz, 2005). and accompanying ACC performance through mindfulness
Neural mechanism of executive attention. Neuroimaging practice is especially promising for the treatment of disorders
research has established that the anterior cingulate cortex that suffer from deficiencies in these functions, such as
(ACC) enables executive attention (van Veen & Carter, 2002) attention-deficit/hyperactivity disorder (ADHD; e.g., Passa-
by detecting the presence of conflicts emerging from incom- rotti, Sweeney, & Pavuluri, 2010) or bipolar disorder (Foun-
patible streams of information processing. During meditation, toulakis, Giannakopoulos, Kovari, & Bouras, 2008). Although
when distracting external events or memories conflict with there is currently insufficient evidence to support the effec-
task goals, ACC activation may contribute to the maintenance tiveness of any type of meditation for ADHD (Krisanapra-
of attention by alerting the systems implementing top-down kornkit, Ngamjarus, Witoonchart, & Piyavhatkul, 2010),
regulation to resolve this conflict (van Veen & Carter, 2002). initial feasibility studies have shown promising effects on
Together with the fronto-insular cortex, the ACC constitutes a improvements in attention (Zylowska et al., 2008). Bipolar
network that is involved in switching between activations of disorder is also associated with impairments in sustained
different brain networks, thereby facilitating cognitive control attention and executive function, as has been established by a
(Sridharan, Levitin, & Menon, 2008). Neurons in these brain large number of empirical investigations (Ancin et al., 2010;
regions have specific properties that enable a rapid relay of Clark, Iversen, & Goodwin, 2002; Kolur, Reddy, John, Kan-
control signals to multiple areas of the brain (Allman, Watson, davel, & Jain, 2006; Kravariti et al., 2009; Maalouf et al.,
Tetreault, & Hakeem, 2005) to initiate responses during cogni- 2010). Neuroanatomical models of bipolar disorder propose a
tively demanding tasks (Sridharan et al., 2008). key role of the ACC, and a meta-analysis has confirmed vol-
Neuroscientific findings on meditation practice. Several neu- ume changes in the ACC as well as state-dependent alterations
roscientific studies have reported the ACC to be implicated in resting state activity in this region (Fountoulakis et al.,
in meditation (Cahn & Polich, 2006). Using functional MRI 2008). Furthermore, ACC activation decreases during cogni-
(fMRI), Hölzel et al. (2007) pursued the question of which tive tasks in bipolar patients (Gruber, Rogowska, & Yurgelun-
brain region would be distinctly activated when meditators Todd, 2004). Mindfulness meditation practice might therefore
performed focused attention meditation. Compared with be beneficial to ameliorate these deficits in cognitive function-
age-, gender-, and education-matched controls, experienced ing and accompanying ACC function by strengthening these
meditators showed greater activation in the rostral ACC skills in bipolar patients (Stange et al., in press). In line with
(Hölzel et al., 2007), suggesting an effect of meditation this hypothesis, a few pilot studies have shown beneficial
practice on ACC activity. A similar effect (greater rostral effects on symptoms in patients with bipolar disorder (Deck-
ACC activation in meditators compared with controls) was ersbach et al., in press; Miklowitz et al., 2009; Williams et al.,How Does Mindfulness Meditation Work? 541
2008). However, further research is needed to assess the effec- to Theravadan interpretations of Buddhist teachings, aware-
tiveness of mindfulness-based treatments on attention regula- ness of the body was taught as the first frame of reference
tion in these disorders. (foundation of mindfulness). In Thanissaro Bhikkhu’s transla-
Effects of meditation practice on further components of atten- tion of the Satipatthana Sutta (Bhikkhu, 2010), the Buddha
tion. Aside from the documented improvements in executive guides the monks with the following meditation instructions:
attention through mindfulness, effects have also been reported In this way he [the monk] remains focused internally on the
on other attention capacities. Within the framework of the net- body in and of itself, or externally on the body in and of itself,
work components described by Posner and Petersen (1990), or both internally and externally on the body in and of itself.
enhanced performance in “orienting” (directing and limiting Or he remains focused on the phenomenon of origination with
attention to a subset of possible inputs) has been found follow- regard to the body, on the phenomenon of passing away with
ing an 8-week mindfulness-based stress reduction course (Jha et regard to the body, or on the phenomenon of origination and
al., 2007) and in experienced meditators, as compared with con- passing away with regard to the body. Or his mindfulness that
trols (van den Hurk et al., 2010). An improvement in “alerting” “There is a body” is maintained to the extent of knowledge
(achieving and maintaining a vigilant state of preparedness) was and remembrance. And he remains independent, unsustained
found in experienced meditators following a 1-month mindful- by (not clinging to) anything in the world. This is how a monk
ness retreat (Jha et al., 2007), as well as a 3-month samatha remains focused on the body in and of itself.
retreat (MacLean et al., 2010). At a neurobiological level, these Self-report findings. Practitioners often self-report that the
findings may relate to functional changes in the dorsal and ven- practice of attending to body sensations results in an enhanced
tral attention systems (Corbetta & Shulman, 2002; Fox, Cor- awareness of bodily states and greater perceptual clarity of
betta, Snyder, Vincent, & Raichle, 2006). These data suggest subtle interoception. In qualitative interviews, 10 experienced
that early stages of mindfulness practice (represented by a short mindfulness meditators were asked what changes they experi-
mindfulness course) may lead to improvement in the function of enced in their lives since they had begun meditating. Seven of
the dorsal attention system involved in orienting, and more the 10 meditators spontaneously reported that they noticed a
intensive open monitoring meditation on a 1-month retreat may more differentiated experience of body sensations, and four of
additionally result in improvements in the function of the ven- them reported greater emotional awareness (Hölzel, Ott, Hem-
tral attention system involved in alerting. pel, & Stark, 2006). Participants in a mindfulness-based stress
Other types of attention tests have shown that 3 months of reduction course further illustrate self-reported changes in
intensive mindfulness meditation lead to a smaller attentional body awareness, as measured by the Five Facet Mindfulness
blink effect (a lapse in attention following a stimulus within a Questionnaire. Body awareness is represented in items of the
rapid stream of presented stimuli) and modified distribution of Observe subscale of the questionnaire, which covers the
brain resources (Slagter et al., 2007; also see van Leeuwen, awareness of body sensations (e.g., Item 1: “When I’m walk-
Willer, & Melloni, 2009). Varying meditation practices will ing, I deliberately notice the sensations of my body moving”),
differentially affect these specific attentional components (see hearing, smelling, seeing, interoceptions, thoughts, and emo-
Lutz, Slagter, et al., 2008, for a review of focused attention tions (e.g., Item 11: “I notice how foods and drinks affect my
versus open monitoring meditation). Future research is neces- thoughts, bodily sensations, and emotions”). Participation in
sary to assess the impact of different types of meditation prac- the mindfulness-based stress reduction course resulted in large
tice on these other attentional components. increases in scores on this scale (Carmody & Baer, 2008).
Attention regulation—in particular conflict monitoring— Behavioral findings. Although meditation practitioners report
seems to be an important mechanism that is often developed improved capability for body awareness, to our knowledge
early in mindfulness practice. A sufficient degree of attention there has been no empirical evidence to verify these claims. In
regulation is necessary in order to stay engaged in meditation, fact, studies that tested this claim by assessing performance
as opposed to drifting off into day dreaming. Thus, successful on a heartbeat detection task, a standard measure of resting
attention regulation might be a building block for practitioners interoceptive awareness, found no evidence that meditators
to also benefit from the other mechanisms of mindfulness had superior performance compared with nonmeditators
practice, which will be described below. This connection (Khalsa et al., 2008; Nielsen & Kaszniak, 2006). However,
between attention regulation and other mechanisms should be awareness of heartbeat sensations is not emphasized during
tested in future research. mindfulness practice and thus may not be the best index of the
awareness cultivated by the practice of meditation. Further
studies are needed that test other types of body awareness,
2. Body awareness such as tactile acuity, which has been shown to be superior in
Body awareness can be understood as the ability to notice experienced Tai Chi practitioners compared with matched
subtle bodily sensations (Mehling et al., 2009). In mindfulness controls (Kerr et al., 2008).
practice, the focus of attention is usually an object of internal Neuroscientific findings: Functional neuroimaging. A number of
experience: sensory experiences of breathing, sensory experi- findings from the mindfulness neuroscience literature point to
ences related to emotions, or other body sensations. According changes in the function and structure of brain regions related542 Hölzel et al.
to body awareness. The insula is commonly activated during own emotional life; in turn, an awareness of one’s emotions is
tasks of interoceptive awareness (Craig, 2003), and its local a precondition for being able to regulate those emotions. Help-
gray matter volume correlates with interoceptive accuracy and ing individuals increase their body awareness can therefore be
visceral awareness (Critchley, Wiens, Rotshtein, Ohman, & considered a relevant aspect in the treatment of psychological
Dolan, 2004). Insula activation has been found to be increased disorders. For example, a lack of awareness of internal experi-
in individuals after a mindfulness-based stress reduction ence—along with problems in emotion regulation—is a cru-
course (compared with individuals who had not practiced cial problem for individuals with borderline personality
mindfulness) when they focused on their momentary experi- disorder, and helping patients increase their internal awareness
ence (i.e., employed an experiential focus; Farb et al., 2007). might be one key element in its treatment (Linehan, Arm-
This study also found increased activation of the secondary strong, Suarez, Allmon, & Heard, 1991; Wupperman, Neu-
somatosensory area, which is relevant for the processing of mann, & Axelrod, 2008). Furthermore, the increase of body
exteroceptive sensory events. In another study, a group of par- awareness is also relevant in the treatment of eating disorders
ticipants that had undergone mindfulness training showed (Hill, Craighead, & Safer, 2011) as well as substance abuse
greater activation of the right insula when being presented disorders. In a pilot study of 16 heroin users in early recovery,
with sad movie clips (Farb et al., 2010). Further neuroscien- high levels of the Observe subscale of the Five Facet Mindful-
tific evidence along the same lines comes from studies on ness Questionnaire were associated with decreased heroin use
mindfulness in the context of pain. When presented with among those at high risk for relapse (Schuman-Olivier, Alba-
unpleasant stimuli during a mindful state, mindfulness medita- nese, Carlini, & Shaffer, 2011), suggesting a role for body
tors show stronger brain activation in the (posterior) insula and awareness in the recovery process.
secondary somatosensory cortex (Gard et al., 2010). Similarly, Body awareness and empathy. Internal awareness of one’s
mindfulness meditators more robustly activated the left ante- own experience has also been suggested to be an important pre-
rior, posterior, and mid-insula as well as the thalamus (Grant, condition for empathic responses. Accurate observations of the
Courtemanche, & Rainville, 2010). The enhanced sensory self are required for the appropriate understanding of others
processing has been suggested to represent increased bottom- (Decety & Jackson, 2004). Self-report studies provide empirical
up processing of the stimulus, that is, awareness of the actual support for the existence of this relationship. A higher level of
sensation of the stimulus as it is. mindful observation, as assessed with the Observe scale of the
Neuroscientific findings: Structural neuroimaging. Two cross- Kentucky Inventory of Mindfulness Skills (Baer, Smith, &
sectional studies comparing the gray matter morphometry of Allen, 2004), has been found to be associated with more engage-
the brains of experienced meditators and controls showed that ment in empathy (Dekeyser, Raes, Leijssen, Leysen, & Dewulf,
meditators had greater cortical thickness (Lazar et al., 2005) 2008), as assessed with the Interpersonal Reactivity Index
and greater gray matter concentration (Hölzel et al., 2008) in (Davis, 1980). Neuroscientific research shows that a subset of
the right anterior insula. Although 8 weeks of mindfulness brain regions (namely, the insula and temporo-parietal junction)
practice did not reveal changes in gray matter concentration in is impacted both in awareness of one’s own body sensations and
the insula (Hölzel et al., 2011), the same study did reveal that in social cognition and empathic responses (Singer et al., 2004).
8 weeks of practice led to increases in gray matter concentra- Enhanced function of these structures following mindfulness
tion in the temporo-parietal junction. It has been suggested training might therefore also correspond to improved empathic
that the temporo-parietal junction is a crucial structure for responses and compassion attributed to meditation training
mediating the first-person perspective of bodily states (Blanke (Shapiro, Schwartz, & Bonner, 1998). Supporting this assump-
et al., 2005), or embodiment (Arzy, Thut, Mohr, Michel, & tion, research has found that Tibetan monks with over 10,000 hr
Blanke, 2006), and that impaired processing at the temporo- of meditation experience showed greater activation of both
parietal junction may lead to the pathological experience of regions during compassion meditation (a meditation that aims at
the self, such as out-of-body experiences (Blanke & Arzy, cultivating feelings of empathy toward the suffering of other
2005). Morphological changes in the temporo-parietal junc- beings and the wish to alleviate their suffering) while they were
tion might be associated with an increased awareness of the presented with auditory stimuli of people suffering (Lutz, Bref-
experience of oneself within the body. Such changes seem to czynski-Lewis, Johnstone, & Davidson, 2008).
correspond with translations of meditation instructions To summarize, body sensations are a common object of
ascribed to the historical Buddha (Bhikkhu, 2010): “His mind- attention during mindfulness meditation, and practitioners
fulness that ‘There is a body’ is maintained to the extent of report improved body awareness. Although there have been no
knowledge and remembrance.” objective behavioral data supporting the increased awareness,
Body awareness and emotion regulation. Body sensations neuroscientific data on mindfulness practice point to the modi-
have been ascribed a crucial role in the conscious experience fication of brain regions involved in first-person conscious
of emotions (feelings), not only historically (James, 1884), but experience of body awareness. The enhancement of body
also currently (Bechara & Naqvi, 2004; Damasio, 1999, 2003). awareness might have relevance for affect regulation and
An increased awareness of the body’s response to an emo- empathic processes and thus may be particularly relevant in
tional stimulus might thus lead to greater awareness of one’s the mindfulness-based treatment of patients with such deficits.How Does Mindfulness Meditation Work? 543
Ongoing attempts to advance the development of instruments Physiological studies also support the proposition that
for the valid assessment of body awareness (Mehling et al., meditation training leads to decreased emotional reactivity
2009) will help to further illuminate this connection. and facilitates a return to emotional baseline after reactivity.
For example, experienced mindfulness meditators have
shown a faster decrease in skin conductance in response to
3. Emotion regulation aversive stimuli (Goleman & Schwartz, 1976), as well as less
In this section, we first describe the general findings regard- enhancement of the startle response by aversive stimuli
ing the effects of mindfulness on emotion regulation. Then (Zeidler, 2007). An electroencephalogram study found that
we focus on two different emotion regulation strategies that mindfulness-based stress reduction training led to increases in
seem to be involved in mindfulness, namely, reappraisal and left-sided anterior brain activation after the course compared
extinction. with a wait-list control group (Davidson et al., 2003). This pat-
Role of emotion regulation in meditation practice. A growing tern of lateralization has previously been associated with the
body of literature suggests that mindfulness practice results in experience of positive emotions (Davidson, 1992). Similarly,
improvements in emotion regulation. Emotion regulation stronger relative left prefrontal activation was also recently
refers to the alteration of ongoing emotional responses through found as a state effect in previously depressed individuals fol-
the action of regulatory processes (Ochsner & Gross, 2005). In lowing a short practice of mindful breathing and loving kind-
Theravadan translations of Buddhist teachings, the alteration ness meditation (Barnhofer, Chittka, Nightingale, Visser, &
of emotional responses is addressed in the Satipatthana Sutta Crane, 2010). These findings support the proposition that
in terms of the overcoming of sorrow and distress as part of mindfulness practice has an effect on the physiological aspects
meditation practice: of positive emotions and thus positively influences emotional
processing.
This is the direct path for the purification of beings, for
the overcoming of sorrow and lamentation, for the disap- Neural mechanisms of emotion regulation. During emo-
pearance of pain and distress, for the attainment of the tion regulation, prefrontal control systems modulate emotion-
right method, and for the realization of Unbinding. . . . He generative systems, such as the amygdala, which is responsible
[the monk] remains focused on feelings . . . mind . . . for the detection of affectively arousing stimuli (Ochsner &
mental qualities in and of themselves—ardent, alert, and Gross, 2005). More specifically, these prefrontal structures
mindful—putting aside greed and distress with reference include dorsal regions of the lateral prefrontal cortex (PFC)
to the world. (Bhikkhu, 2010) that have been implicated in selective attention and working
memory; ventral parts of the PFC implicated in response inhi-
Behavioral and peripheral physiological finding. Studies bition; the ACC, which is involved in monitoring control pro-
from the field of mindfulness research have addressed cesses; and the dorso-medial PFC implicated in monitoring
improvements in emotion regulation through a variety of one’s affective state (Modinos, Ormel, & Aleman, 2010; Och-
approaches, including experimental, self-report, peripheral sner & Gross, 2008). A typical pattern detected when individu-
physiological, and neuroimaging data. Healthy novices als deliberately regulate affective responses is increased
enrolled in a 7-week mindfulness training program showed a activation within the PFC and decreased activation in the
reduction in emotional interference (assessed as the delay in amygdala (Beauregard, Levesque, & Bourgouin, 2001; Haren-
reaction time after being presented with affective versus neu- ski & Hamann, 2006; Schaefer et al., 2002), suggesting that
tral pictures) compared with those who followed a relaxation PFC projections to the amygdala exert an inhibitory top-down
meditation protocol and those in a wait-list control group influence (Banks, Eddy, Angstadt, Nathan, & Phan, 2007;
(Ortner et al., 2007). Both the mindfulness and relaxation Davidson, Jackson, & Kalin, 2000).2
meditation groups also displayed significant reductions in
physiological reactivity during the task. Furthermore, in a Psychological disorders and emotion regulation. A variety
group of long-term practitioners, participants with more mind- of psychological disorders are associated with reduced emo-
fulness meditation experience showed less emotional interfer- tion regulation capacity (Cicchetti, Ackerman, & Izard, 1995;
ence than did less experienced practitioners. Studies using Davidson, 2000; Gross, 1998; Hayes, Wilson, Gifford, Fol-
self-report data from healthy individuals have shown that lette, & Strosahl, 1996; Mennin, Heimberg, Turk, & Fresco,
mindfulness meditation decreased negative mood states (Jha, 2002). Disorders characterized by a deficit in emotion regula-
Stanley, Kiyonaga, Wong, & Gelfand, 2010), improved posi- tion are frequently associated with dysfunction in the frontal-
tive mood states, and reduced distractive and ruminative limbic network, that is, reduced prefrontal activation and
thoughts and behaviors (Jain et al., 2007). A questionnaire exaggerated amygdala activation (e.g., depression, H. C.
study investigating the immediate effects of brief (15-min) Abercrombie et al., 1998; borderline personality disorder, Sil-
stress management interventions found that mindful breathing bersweig et al., 2007; bipolar disorder, Pavuluri, O’Connor,
may help to reduce reactivity to repetitive thoughts (Feldman, Harral, & Sweeney, 2007; social phobia, Phan, Fitzgerald,
Greeson, & Senville, 2010). Nathan, & Tancer, 2006; obsessive-compulsive disorder,544 Hölzel et al.
Breiter & Rauch, 1996; posttraumatic stress disorder, Shin et al., regulation strategies that might be influenced by mindfulness
2005; impulsive aggression, Coccaro, McCloskey, Fitzgerald, & practice.
Phan, 2007; addiction, Bechara, 2005; generalized anxiety, Monk There are several proposed classifications for different
et al., 2008; and trait anxiety, Etkin et al., 2004). kinds of emotion regulation (Ochsner & Gross, 2005; Parkin-
son & Totterdell, 1999). Ochsner and Gross (2005) have sug-
Neuroscientific findings on mindfulness and emotion reg- gested a distinction between behavioral regulation (e.g.,
ulation. In contrast to psychiatric disorders that are character- suppressing expressive behavior) and cognitive regulation.
ized by suboptimal or deficient emotion regulatory responses Cognitive regulation can rely on attentional control (e.g.,
and corresponding abnormalities in brain activation patterns, a selective inattention to emotional stimuli, performing distract-
few neuroimaging studies have found increased prefrontal ing secondary tasks) or on cognitive change. Cognitive change
activation and improved prefrontal control over amygdala strategies include the controlled regulation of an ongoing
responses in association with mindfulness. The earliest evi- emotional response, such as reappraisal (i.e., reinterpreting
dence for the neurophysiological basis of differences in emo- the meaning of a stimulus to change one’s emotional response
tion regulation according to dispositional levels of mindfulness to it) and extinction (stimulus-response reversal). As discussed
was found in a study that investigated the effect of disposi- in Section 1, attentional control plays a crucial role in mindful-
tional (trait) mindfulness on brain activation while healthy ness meditation. Whereas typical contemporary descriptions
participants labeled the affect of emotional facial expressions regard attentional control in emotion regulation as adaptive
(Creswell, Way, Eisenberger, & Lieberman, 2007). Higher dis- when attention is directed away from emotionally distressing
positional mindfulness, as measured by the Mindful Attention material, mindfulness usually involves bringing attention to
Awareness Scale, predicted (a) increased activation at multiple the stimulus. Keeping attention on an emotional reaction leads
sites of the prefrontal cortex (including the ventromedial PFC, to a situation of exposure with a subsequent extinction pro-
medial PFC, and ventrolateral PFC), (b) reduced amygdala cess. Extinction plays a crucial role in producing the beneficial
activity, and (c) a stronger inhibitory association between effects of mindfulness meditation and will be discussed in
amygdala activity and regions of the PFC. detail below. The following section explores the role of
Although the above mentioned study investigated disposi- reappraisal.
tional mindfulness in individuals without any mindfulness
training, other studies have reported evidence that mindful- Reappraisal. Reappraisal has been suggested to be one of the
ness meditation involves activation of brain regions relevant ways in which emotion gets regulated during mindfulness.
for emotion regulation, and thus activation of these regions Garland et al. (2011) described mindful emotion regulation as
might be modified through mindfulness practice. During “positive reappraisal,” or the adaptive process through which
mindfulness meditation, experienced mindfulness meditators stressful events are reconstrued as beneficial, meaningful, or
show greater activation in the dorso-medial PFC and rostral benign (e.g., thinking that one will learn something from a dif-
ACC compared with nonmeditators (Hölzel et al., 2007). After ficult situation). A very recent self-report study showed that
participants completed an 8-week mindfulness-based stress mindfulness practice leads to increases in positive reappraisal
reduction course, Farb et al. (2007) found increased activity in and that these increases mediate an improvement in stress lev-
participants’ ventrolateral PFC, which the authors interpreted els (Garland et al., 2011).
as augmented inhibitory control. Following participation in a
mindfulness-based stress reduction course, social anxiety Neuroscientific findings. Cognitive reappraisal of aversive
patients presented with negative self-beliefs showed a quicker stimuli has been found to coincide with activity in the dorso-
decrease of activation in the amygdala as compared with mea- lateral PFC, orbitofrontal PFC, and ACC (Eippert et al., 2007;
sures taken before course completion (Goldin & Gross, 2010). Ochsner, Bunge, Gross, & Gabrieli, 2002; Ochsner et al.,
The observed improvements in emotion regulation associ- 2004), and dorsal PFC activity has been found to go along
ated with mindfulness practice likely underlie many of the posi- with reappraisal success (Modinos et al., 2010; Wager, David-
tive effects of mindfulness practice on mental health. Indeed, son, Hughes, Lindquist, & Ochsner, 2008). Thus, whereas
improved emotion regulation underlies the beneficial effects of extinction processes may depend more upon ventral frontal
mindfulness practice on stress reduction (Garland, Gaylord, & systems (such as the ventromedial PFC) that are directly con-
Fredrickson, 2011) and on reductions of depressive symptoms nected with the subcortical systems (see Exposure, extinction,
(Shahar, Britton, Sbarra, Figueredo, & Bootzin, 2010). and reconsolidation for details), reappraisal may depend more
on dorsal frontal systems (Ochsner & Gross, 2008).
Different strategies of emotion regulation. Although it To investigate the neural correlates of dispositional mind-
seems well established that mindfulness has positive effects on fulness in the context of reappraisal, Modinos et al. (2010)
emotion regulation, the exact processes underlying these assessed fMRI study participants’ individual differences in
improvements seem less clear. Emotion regulation is an dispositional mindfulness with the Kentucky Inventory of
umbrella term for a wide array of strategies for altering emo- Mindfulness Skills and asked the participants to either attend
tional responses. Here, we will consider some emotion to or reappraise negative pictures. Findings showed that levelsHow Does Mindfulness Meditation Work? 545
of dispositional mindfulness were positively correlated with “positive reappraisal,” and correspondingly, studies find
activations in the left and right dorsomedial PFC during the enhanced brain activity in multiple prefrontal regions involved
reappraisal condition. Therefore, trait mindfulness seems to be in cognitive change strategies. However, other studies have
positively associated not only with reappraisal success but conceptualized the changes as “nonappraisal” and have identi-
also with increased activation in brain regions that support this fied decreased brain activity in prefrontal regions. Further
kind of emotion regulation. research is needed to test the hypothesis that the amount of
required prefrontal control decreases with increased expertise.
Does mindfulness involve reappraisal or nonappraisal? In the following section, we will turn toward exposure, extinc-
Although the above findings suggest increased “reappraisal” tion, and reconsolidation as a further mechanism of action of
related to mindfulness (Garland et al., 2011), there also seems mindfulness meditation.
to be some inconsistency in the literature. Other work has
identified decreased cognitive control associated with mind- Exposure, extinction, and reconsolidation. During mind-
fulness meditation, interpreted as nonappraisal. As mentioned fulness, practitioners expose themselves to whatever is present
earlier in the section on body awareness, experienced medita- in the field of awareness, including external stimuli as well as
tors, when presented with unpleasant or painful stimuli during body sensations and emotional experiences. They let them-
a mindful state (Gard et al., 2010) or a baseline state (Grant, selves be affected by the experience, refraining from engaging
Courtemanche, & Rainville, 2011) showed enhanced sensory in internal reactivity toward it, and instead bringing accep-
processing, that is, increased bottom-up processing of the tance to bodily and affective responses (Hart, 1987). Practitio-
stimulus. At the same time, decreased prefrontal activation ners are instructed to meet unpleasant emotions (such as fear,
was observed in meditators in both studies when they were sadness, anger, and aversion) by turning towards them, rather
presented with the painful stimuli. These findings were than turning away (Santorelli, 2000). Those people who are
explained with a decrease in top-down control, representing a new to meditation often initially find this process counterintui-
lack of reappraisal. tive, but many practitioners discover that the unpleasant emo-
This discrepancy brings to light a question: Does emotion tions pass away and a sense of safety or well-being can be
regulation during mindfulness involve cognitive control (and experienced in their place.
corresponding prefrontal engagement), or is it characterized Parallels between the process described here and exposure
instead by its absence? Whereas the acceptance of one’s emo- therapy are evident. Exposure therapy is a highly effective
tional response is characterized by the absence of active cogni- behavioral therapy technique for reducing fear and anxiety
tive control over the emotional reaction, bringing mindful responses (Chambless & Ollendick, 2001). Its core element is
awareness to emotional responses might initially require some to expose patients to fear-provoking stimuli and prevent their
cognitive control, in order to overcome habitual ways of inter- usual response in order for them to extinguish the fear response
nally reacting to one’s emotions. Although currently specula- and to instead acquire a sense of safety in the presence of the
tive, it seems possible that the degree of meditation expertise formerly feared stimuli (Öst, 1997). Clinical studies on expo-
of the individual might be relevant when considering the ques- sure therapy show that access to safety behaviors can interfere
tion of whether mindfulness involves cognitive control or its with the beneficial effects of an exposure situation (Lovibond,
absence. Whereas beginners might require more active cogni- Mitchell, Minard, Brady, & Menzies, 2009; Salkovskis, Clark,
tive regulation in order to approach ongoing emotional reac- Hackmann, Wells, & Gelder, 1999; Wells et al., 1995). Safety
tions in a different way and might therefore show greater behaviors include not only overt behavior (such as avoiding
prefrontal activation, expert meditators might not employ this eye contact in social phobia) but also cognitive avoidance.
prefrontal control. Rather, they might use different strategies; Mindfulness meditation includes refraining from engaging in
they may have automated an accepting stance toward their cognitive avoidance or other safety behaviors by using
experience so they no longer require cognitive control efforts, enhanced attention regulation skills, thereby maximizing the
and they could have different baseline blood flow as a conse- exposure to the experienced emotion.
quence of plastic processes. A similar interpretation has previ- Additionally, meditation is often associated with high lev-
ously been suggested by Brefczynski-Lewis et al. (2007) in els of relaxation in the form of increased parasympathetic tone
regard to attentional control. and decreased sympathetic activity (Benson, 2000). Peripheral
To summarize, several studies have demonstrated improve- physiological changes have been observed with some consis-
ments in emotion regulation associated with mindfulness. Psy- tency (but see Shapiro, 1982), including decreased heart rate
chological disorders characterized by problems in emotion (Zeidan, Johnson, Gordon, & Goolkasian, 2010), decreased
regulation, such as mood disorders, anxiety disorders, or bor- blood pressure (de la Fuente, Franco, & Salvator, 2010),
derline personality disorder, can benefit from the enhancement decreased cortisol levels (Carlson et al., 2007), decreased
of emotion regulation capacities. Different emotion regulation breathing rate (Lazar et al., 2005), lowered oxygen and carbon
strategies might show improvements following mindfulness dioxide consumption (Young & Taylor, 1998), decreased skin
practice. Some studies have conceptualized the improved conductance response (Austin, 2006), and decreased muscle
emotion regulation associated with mindfulness practice as tension (Benson, 2000). Since extinction mechanisms are546 Hölzel et al.
thought to be supported by the experience of a state of relax- 2005) positively correlated with extinction recall. In addition,
ation while the individual encounters the feared stimuli hippocampal activation has also been found to be involved in
(Wolpe, 1958), the relaxation component of meditation might fear extinction recall. Functional connectivity analysis reveals
serve to maximize the effects of the extinction process. that the vmPFC and hippocampus work in concert during
In the Five Facet Mindfulness Questionnaire, the capacity extinction recall to inhibit fear, suggesting that they comprise
to expose oneself to internal experience without reactivity is a network that mediates the expression of extinction memory
captured in the Non-Reactivity to Inner Experience Scale. in the appropriate context (Milad et al., 2007). Hippocampal
Example items are “In difficult situations, I can pause without activation during extinction recall is likely related to signaling
immediately reacting” (Item 21), or “When I have distressing the extinguished context (contextual safety; Corcoran, Des-
thoughts or images I am able just to notice them without react- mond, Frey, & Maren, 2005; Corcoran & Maren, 2001). The
ing” (Item 29). With completion of a mindfulness-based stress amygdala has been implicated in both human and animal stud-
reduction course, scores on this scale increase with large effect ies as playing a crucial role during the acquisition and expres-
sizes (Carmody & Baer, 2008), corroborating the theory that sion of conditioned fear (Davis & Whalen, 2001; LeDoux,
mindfulness practice leads to the self-perception of decreased 2000; Pare, Quirk, & Ledoux, 2004; Phelps & LeDoux, 2005),
reactivity. This likely is a mechanism for facilitating including the detection of stressful and threatening stimuli and
exposure. the initiation of adaptive coping responses (Hasler et al.,
2007). When individuals regulate their emotions, the amyg-
Fear conditioning, extinction, and reconsolidation. The pro- dala is thought to be down-regulated by the vmPFC and hip-
cess of fear extinction has been studied extensively in the con- pocampus (Banks et al., 2007; Davidson et al., 2000; Milad,
text of conditioned fear. Fear conditioning is a learning process Rauch, Pitman, & Quirk, 2006), both of which have extensive
in which a neutral conditioned stimulus (e.g., a tone) is paired connections with the amygdala. This inhibition of the amyg-
with an aversive unconditioned stimulus (e.g., a shock). After a dala serves to suppress fear (Milad et al., 2006; Rauch, Shin,
few pairings, the presentation of the conditioned stimulus comes & Phelps, 2006), thereby allowing control over behavioral
to also elicit various fear responses (e.g., freezing in animals; reactions to emotions (Price, 2005). Deficits in fear extinction
sympathetic arousal in humans). Repeated presentations of the are thought to be related to a number of psychiatric disorders,
conditioned stimulus in the absence of the unconditioned stimu- and neuroimaging studies have shown that the aforementioned
lus result in the extinction of the conditioned responses. Extinc- structures are dysfunctional in several psychiatric disorders,
tion does not erase the initial association between conditioned such as posttraumatic stress disorder (Milad et al., 2009),
and unconditioned stimuli but is thought to form a new memory schizophrenia (Holt et al., 2009), and depression (Anand et al.,
trace (Quirk, 2002; Rescorla, 2001) or reconsolidate the old 2005).
memory with new contextual associations (Inda, Muravieva, &
Alberini, 2011; Nader & Einarsson, 2010; Rossato, Bevilaqua, Effects of meditation practice on the neural network
Izquierdo, Medina, & Cammarota, 2010). After extinction train- underlying extinction. There is recent evidence from ana-
ing, extinction memory is thought to compete with conditioned tomical MRI studies that the aforementioned brain regions
memory for control of fear expression (Myers & Davis, 2007). show structural changes following mindfulness meditation
Recent research has shown that successful extinction memory training. Cross-sectional studies comparing mindfulness med-
reliably differentiates healthy from pathological conditions itators and nonmeditators found that meditators showed
(Holt et al., 2009; Milad et al., 2008). Extinction learning and its greater gray matter concentration in the hippocampus (Hölzel
retention may thus be a critical process in the transformation of et al., 2008; Luders, Toga, Lepore, & Gaser, 2009). Further-
maladaptive states. It allows individuals to learn not to have a more, Hölzel et al. (2011) recently observed that structural
fear response to neutral stimuli, when there is no adaptive func- changes in the hippocampus were detectable within a period
tion for the fear response. Rather, individuals can flexibly elicit of only 8 weeks in participants that underwent mindfulness-
other more adaptive emotional and behavioral responses. based stress reduction, and Hölzel et al. (2008) found that
cumulative hours of meditation training were positively
Neural mechanisms of fear extinction and extinction correlated with gray matter concentration in the vmPFC in
retention. Recent fMRI research on fear conditioning has experienced meditators. In a longitudinal study enrolling par-
identified a network of brain regions that are crucial for the ticipants in an 8-week mindfulness-based stress reduction
extinction of conditioned fear responses and its retention. As course, Hölzel et al. (2010) found an impact of the stress-
outlined below, this network seems to strengthen through reducing effects of mindfulness meditation on the amygdala;
mindfulness practice. The ventromedial prefrontal cortex the greater the decrease in participants’ scores on perceived
(vmPFC) has been shown to be important for the successful stress over the 8 weeks, the greater a decrease they showed in
recall of the extinction (Milad & Quirk, 2002; Morgan, gray matter concentration in the right amygdala. Modified
Romanski, & LeDoux, 1993; Quirk, Russo, Barron, & Lebron, gray matter concentration in these regions that is dependent on
2000), with the magnitude of vmPFC activation (Milad et al., meditation training might potentially be related to the improved
2007) and the cortical thickness of the vmPFC (Milad et al., ability to regulate emotional responses. Furthermore, fMRIYou can also read
