Neural mechanisms of mindfulness and meditation: Evidence from neuroimaging studies

Table 1 Functional imaging studies of mindfulness and meditation

Ref.	Mindfulness intervention or condition	Result
Allen et al[11]	Mindfulness	Diminished Stroop conflict and greater DLPFC responses during executive processing.
Baerentsen et al[22]	Meditators	At onset of meditation, activations occurred bilaterally in putamen and supplementary motor cortex with deactivations in the precuneus, the posterior cingulate cortex and the parieto-temporal area. With sustained meditation, activations were found in the caudate and deactivations were in right hemisphere white matter.
Brefczynski-Lewis et al[40]	Experienced meditators	Activation during sustained attention showed an inverted curve. Expert meditators (average 19000 h) of practice had more activation than novices but experts (average 44000 h) had less activation. In response to distracter sounds, expert meditators had less brain activation in areas associated with discursive thoughts and emotions but more activation in regions related to response inhibition and attention compared to novices.
Creswell et al[39]	Dispositional mindfulness	Dispositional mindfulness was associated with widespread prefrontal cortical activation, and decreased bilateral amygdala activity during affect labeling. Negative associations were found between prefrontal cortex and right amygdala responses in participants high in mindfulness.
Desbordes et al[12]	Mindfulness training	Decreased right amygdala activation in response to positive images.
Dickenson et al[34]	Brief mindfulness induction	Focused breathing activated a parietal and prefrontal attention network and trait-level mindfulness correlated with parietal activation.
Farb et al[6]	MBSR	Interoceptive attention predicted greater activity in anterior insula but decreased recruitment of the DMPFC as well as altered functional connectivity between the DMPFC and the insula.
Farb et al[7]	Mindfulness training	Experiential focus resulted in reductions in cortical midline regions associated with narrative focus in novices. In trained participants, experiential focus was associated with reductions in the mPFC and increased engagement the lateral PFC, insula and somatosensory area. Analyses of functional connectivity revealed coupling between the insula and the mPFC in novices that was uncoupled in the mindfulness group.
Farb et al[14]	Mindfulness training	Participants had right-lateralized recruitment, including visceral and somatosensory areas associated with body sensation.
Gard et al[25]	Healthy meditators	Mindfulness practitioners experienced reduced unpleasantness of pain, which was associated with decreased activation in the lateral PFC and increased activation in the right insula. Anticipation of pain was associated with increased anterior cingulate cortex activation.
Garrison et al[30]	Healthy meditators	“Undistracted awareness" was associated with PCC deactivation. In contrast, "distracted awareness" corresponded with PCC activation.
Garrison et al[31]	Healthy meditators	Volitional decrease of the feedback graph was associated with deactivation of the PCC.
Goldin et al[8]	MBSR for social anxiety disorder	MBSR yielded greater reductions in negative emotion and increased activation in attention-related parietal cortex compared to aerobic exercise.
Goldin et al[13]	MBSR for social anxiety disorder	MBSR led to increased activation in the PCC during negative self-view condition. DMPFC activation increases during negative self-view were associated with decreased disability and enhanced mindfulness.
Goldin et al[15]	MBSR for social anxiety disorder	MBSR associated with decreased anxiety and depression symptoms and improved self-esteem. Breath-focused attention task associated with decreased negative emotion and reduced amygdala activation.
Hasenkamp et al[26]	Healthy meditators	Brain activation in DMN during mind wandering, and in salience network regions during awareness of mind wandering.
Hasenkamp et al[27]	Healthy meditators	Meditation experience was associated with increased connectivity within attention networks and between regions involved with attention and medial frontal cortex.
Hölzel et al[16]	MBSR for GAD	Amygdala activation in response to neutral faces decreased, VLPFC activation increased and functional connectivity between amygdala and PFC increased. Changes in VLPFC activation and amygdala-PFC connectivity correlated with changes in Beck Anxiety Inventory scores.
Hölzel et al[20]	Vipassana meditators	Meditation associated with increased activation in ACC and dorsal medial prefrontal cortex.
Ives-Deliperi et al[17]	MBCT for bipolar disorder	Activation increased in the medial PFC and posterior parietal lobe, in response to a mindfulness task. There was a correlation between activation changes in medial PFC and increased mindfulness.
Ives-Deliperi et al[36]	State mindfulness	Decreased activation in anterior insula, ACC, medial prefrontal cortex and bilateral precuneus during mindfulness meditation.
Kilpatrick et al[9]	MBSR	Increased functional connectivity of auditory and visual networks as well as between auditory cortex and areas associated with attention and self-referential processes. Enhanced anticorrelation between auditory and visual cortex as well as between visual cortex and attention and self-referential processing areas.
Kirk et al[23]	Experienced meditators	During the Ultimatum Game, controls recruit the anterior insula during unfair offers. In contrast, meditators display attenuated activity in high-level emotional representations of the anterior insula and increased activity in the low-level interoceptive representations of the posterior insula.
Kozasa et al[28]	Healthy meditators	Meditators had decreased activity relative to non-meditators in medial frontal, temporal, precentral, postcentral and basal ganglia regions during the incongruent conditions of the Stroop task.
Lutz et al[32]	Healthy subjects	Mindfulness increased activations in prefrontal regions during expectation of negative pictures. During perception of negative stimuli, reduced activation was found in amygdala and parahippocampal regions. Prefrontal and insular activations when expecting negative pictures correlated negatively with trait mindfulness.
Lutz et al[35]	Experienced meditators	Enhanced activity in the anterior insula and the mid-cingulate was associated with decreased pain-related unpleasantness.
Pagnoni et al[21]	Experienced meditators	vPMC activity was lower in meditators and was correlated with performance on a test for sustained attention. Functional connectivity analysis with a vPMC seed revealed attention performance was associated with the degree of temporal correlation between vPMC and the temporoparietal junction.
Pagnoni et al[29]	Zen meditators	Practitioners displayed reduced duration of the neural response linked to conceptual processing in regions of the DMN.
Paul et al[38]	Healthy subjects	Non-reactivity was inversely correlated with insula activation during inhibition to negative stimuli.
Shaurya Prakash et al[37]	Mindfulness disposition	Mindfulness disposition was associated with greater connectivity of the DMN, particularly in the PCC and the precuneus.
Taylor et al[24]	Experienced and beginning meditators	Experienced meditators had weaker functional connectivity between DMN regions.
Taylor et al[33]	Experienced and beginning meditators	Mindfulness attenuated emotional intensity. For experienced meditators, mindfulness induced a deactivation of DMN areas. For beginners, mindfulness induced a down-regulation of the left amygdala.
Wells et al[19]	MBSR	Increased functional connectivity between the PCC and medial prefrontal cortex and left hippocampus.
Baerentsen et al[22]	Mindfulness training	Reduced smoking craving associated with reduced activation of ACC. Mindful attention reduced functional connectivity between ACC and other craving-related regions.
Zeidan et al[10]	Mindfulness training	Anxiety relief associated with activation of the PFC and insula.
Zeidan et al[18]	Mindfulness training	Meditation decreased pain-associated activation of the contralateral somatosensory cortex. Reductions in pain were associated with increased activity in the ACC and insula. Decreased pain unpleasantness was associated with orbitofrontal activation and thalamic deactivation.

ACC: Anterior cingulate cortex; DMN: Default mode network; PCC: Posterior cingulate cortex; DMPFC: Dorsomedial prefrontal cortex; mPFC: Medial prefrontal cortex; vLPFC: Ventrolateral prefrontal cortex; vPMC: Ventral posterior medial cortex.

Table 2 Brain regions where structural imaging studies have demonstrated mindfulness related changes

Anterior cingulate cortex[42,51]

Orbitofrontal cortex[41]

Inferior temporal gyrus[49]

Insula[49,53]

Lingual gyrus[45]

Cuneus[45]

Sensorimotor cortex[42,53]

Fusiform gyrus[53]

Cuneus[53]

Corpus callosum[52]

Posterior cingulate cortex[48]

Cerebellum[48]

Hippocampus[19,41,45-49]

Amygdala[43-45]

Putamen[50]

Caudate[44,45]

Thalamus[45]

Table 3 Brain regions involved with mindfulness mechanisms

Frontal cortex[6,10,11,14,16-18,20,25,28,32-36,39]

Lateral frontal cortex[11,16,25]

Ventrolateral prefrontal cortex[16]

Dorsolateral prefrontal cortex[11]

Medial frontal cortex[6,10,13,14,17,18,20,25,27,28,33,36]

Anterior cingulate cortex[10,18,20,25,36]

Orbitofrontal cortex[10]

Posterior medial cortex[13,22,29-31,33,36,37]

Posterior cingulate cortex/precuneus[13,22,30,31,33,36,37]

Ventral posteromedial cortex[29]

Insula[6,10,14,18,23,25,32,35,38]

Temporal cortex[28,33]

Temporoparietal junction[29]

Sensorimotor cortex[6,10,28]

Inferior parietal lobule[6,33]

Parahippocampal gyrus[35]

Amygdala[8,12,16,24,32,35,39]

Basal ganglia[22,28]

Thalamus[10]