Meditation
Meditation is a method used to focus the mind on a particular state of consciousness. It has an extremely long history in asian cultures and is often tied to religion. In more recent times meditation has become of interest for a number of different applications. As meditation can be thought of as a type of exercise or training for the mind researchers want to know if it confers any cognitive benefits. There has been a lot of research carried out on meditation and cognition. All of the studies below demonstrate some sort of benefit from meditation. The types of studies vary and compliment each other when trying to explain the observed benefits. There are numerous studies demonstrating that compared to control groups, meditators show cognitive improvements within a single session. These benefits become more pronounced the more experienced the meditator is. Other studies demonstrate how increased meditation experience is correlated with increased thickness and blood flow to particular brain regions. The most common facets of cognition improved by meditation appear to be attention and flexibility, however numerous other abilities have also demonstrated improvement. Meditation is almost certainly a cognitive enhancing technique that is different from other interventions and has the ability to improve more difficult to improve cognitive abilities such as mental flexibility and attention.
Most beneficial for - Anyone.
Effective dose - Benefits reported with mindfulness, transcendental and concentrative styles.
Length of action - Benefits reported after a single session but continue to improve with practice.
Safety - No adverse effects reported.
Type cognition effected - visuo-spatial processing, working memory, executive functioning, attention, cognitive flexibility and mental fatigue.
Enhancers - not known
Supporting Human Studies
Mindfulness Meditation Improves Cognition: Evidence of Brief Mental Training (Zeidan, Johnson, Diamond, David and Goolkasian, 2010)
This study examined whether brief mindfulness meditation training affects cognition and mood. Participants with no former mediation experiences were assigned 4 meditation sessions or a control group (listening to an audiobook). At the end of these sessions both groups underwent tests for mood, verbal fluency, visual coding and working memory. Mood improved in both groups however only the meditation group showed reduced fatigue, anxiety and increased mindfulness. The meditation also significantly improved visuo-spatial processing, working memory and executive functioning.
Meditation, Mindfulness and Cognitive Flexibility (Moore and Malinowski, 2009)
This study investigated the link between meditation, self-reported mindfulness and cognitive flexibility as well as other attentional functions. It compared a group of meditators experienced in mindfulness meditation with a meditation-naïve control group on measures of Stroop interference and the “d2-concentration and endurance test”. Overall the results suggest that attentional performance and cognitive flexibility are positively related to meditation practice and levels of mindfulness. Meditators performed significantly better than non-meditators on all measures of attention. Furthermore, self-reported mindfulness was higher in meditators than non-meditators and correlations with all attention measures were of moderate to high strength. This pattern of results suggests that mindfulness is intimately linked to improvements of attentional functions and cognitive flexibility.
Meditation and attention: A comparison of the effects of concentrative and mindfulness meditation on sustained attention (Valentine and Sweet, 1999)
The performance of concentrative and mindfulness meditators on a test of sustained attention (Wilkins' counting test) was compared with controls. Both groups of meditators demonstrated superior performance on the test of sustained attention in comparison with controls, and long-term meditators were superior to short-term meditators. Mindfulness meditators showed superior performance in comparison with concentrative meditators when the stimulus was unexpected but there was no difference between the two types ofmeditators when the stimulus was expected.
Mindfulness training modifies subsystems of attention (Jha et al, 2007)
This study investigates the hypothesis that mindfulness training may alter or enhance specific aspects of attention. It examined three functionally and neuroanatomically distinct but overlapping attentional subsystems: alerting, orienting, and conflict monitoring. Functioning of each subsystem was measured by performance on the Attention Network Test. Two types of mindfulness training (MT) programs were examined, and behavioral testing was conducted on participants before (Time 1) and after (Time 2) training. One training group consisted of individuals naive to mindfulness techniques who participated in an 8-week mindfulness-based stress reduction (MBSR) course that emphasized the development of concentrative meditation skills. The other training group consisted of individuals experienced in concentrative meditation techniques who participated in a 1-month intensive mindfulness retreat. Performance of these groups was compared with that of control participants who were meditation naive and received no MT. At Time 1, the participants in the retreat group demonstrated improved conflict monitoring performance relative to those in the MBSR and control groups. At Time 2, the participants in the MBSR course demonstrated significantly improved orienting in comparison with the control and retreat participants. In contrast, the participants in the retreat group demonstrated altered performance on the alerting component, with improvements in exogenous stimulus detection in comparison with the control and MBSR participants. The groups did not differ in conflict monitoring performance at Time 2.
Three Randomised Experiments on the Longitudinal Effects of the Transcendental Meditation Technique on Cognition (So and Orme-Johnson, 2001)
Three studies on 362 high school students at three different schools in Taiwan tested the hypothesis that regular practice of the Transcendental Meditation (TM) technique for 15–20 min twice a day for 6 to 12 months would improve cognitive ability. The students completed test for Creative Thinking-Drawing Production, Constructive Thinking Inventory, Group Embedded Figures Test, State and Trait Anxiety, Inspection Time and Culture Fair Intelligence Test. Univariate testing showed that TM practice produced significant effects on all variables compared to no-treatment controls. Napping for equivalent periods of time as TM practice had no effect. Contemplation meditation improved inspection time and embedded figures, but not the other variables. The TM technique was superior to contemplation meditation on five variables.
Short-term meditation training improves attention and self-regulation (Tang et al, 2007)
This article shows that a group randomly assigned to 5 days of meditation practice with the integrative body–mind training method shows significantly better attention and control of stress than a similarly chosen control group given relaxation training. The training method comes from traditional Chinese medicine and incorporates aspects of other meditation and mindfulness training. Compared with the control group, the experimental group of 40 undergraduate Chinese students given 5 days of 20-min integrative training showed greater improvement in conflict scores on the Attention Network Test, lower anxiety, depression, anger, and fatigue, and higher vigor on the Profile of Mood States scale, a significant decrease in stress-related cortisol, and an increase in immunoreactivity.
Investigating the impact of mindfulness meditation training on working memory: A mathematical modeling approach (van Vugt and Jha, 2011)
This study investigated whether mindfulness training (MT) influences information processing in a working memory task with complex visual stimuli. Participants were tested before (T1) and after (T2) participation in an intensive one-month MT retreat, and their performance was compared with that of an age- and education-matched control group. Accuracy did not differ across groups at either time point. Response times were faster and significantly less variable in the MT versus the control group at T2. Since these results could be due to changes in mnemonic processes, speed–accuracy trade-off, or nondecisional factors (e.g., motor execution), we used a mathematical modeling approach to disentangle these factors. The EZ-diffusion model suggested that MT leads to improved information quality and reduced response conservativeness, with no changes in nondecisional factors. The noisy exemplar model further suggested that the increase in information quality reflected a decrease in encoding noise and not an increase in forgetting.
Effects of Level of Meditation Experience on Attentional Focus: Is the Efficiency of Executive or Orientation Networks Improved? (Chan and Woolacott, 2007)
Participants (50 meditators and 10 controls) were given the Stroop (measures executive attention) and Global-Local Letters (measures orientational attention) tasks. Results showed that meditation experience was associated with reduced interference on the Stroop task (p < 0.03), in contrast with a lack of effect on interference in the Global-Local Letters task. This suggests that meditation produces long-term increases in the efficiency of the executive attentional network (anterior cingulate/prefrontal cortex) but no effect on the orientation network (parietal systems). The amount of time participants spent meditating each day, rather than the total number of hours of meditative practice over their lifetime, was negatively correlated with interference on the Stroop task (r = −0.31, p < 0.005).
Perceptual Discrimination and Sustained Attention (MacLean et al, 2010)
The ability to focus one’s attention underlies success in many everyday tasks, but voluntary attention cannot be sustained for extended periods of time. In the laboratory, sustained-attention failure is manifest as a decline in perceptual sensitivity with increasing time on task, known as the vigilance decrement. We investigated improvements in sustained attention with training (~5 hr/day for 3 months), which consisted of meditation practice that involved sustained selective attention on a chosen stimulus (e.g., the participant’s breath). Participants were randomly assigned either to receive training first (n = 30) or to serve as waiting-list controls and receive training second (n = 30). Training produced improvements in visual discrimination that were linked to increases in perceptual sensitivity and improved vigilance during sustained visual attention. Consistent with the resource model of vigilance, these results suggest that perceptual improvements can reduce the resource demand imposed by target discrimination and thus make it easier to sustain voluntary attention.
Meditation Experience is Associated with Increased Cortical Thickness (Lazar et al, 2006)
Magnetic resonance imaging was used to assess cortical thickness in 20 participants with extensive Insight meditation experience, which involves focused attention to internal experiences. Brain regions associated with attention, interoception and sensory processing were thicker in meditation participants than matched controls, including the prefrontal cortex and right anterior insula. Between-group differences in prefrontal cortical thickness were most pronounced in older participants, suggesting that meditation might offset age-related cortical thinning.
The Enhancement of Visuospatial Processing Efficiency Through Buddhist Deity Meditation (Kozhevnikov et al, 2009)
This study examined the effects of meditation on mental imagery, evaluating Buddhist monks' reports concerning their extraordinary imagery skills. Practitioners of Buddhist meditation were divided into two groups according to their preferred meditation style: Deity Yoga (focused attention on an internal visual image) or Open Presence (evenly distributed attention, not directed to any particular object). Both groups of meditators completed computerized mental-imagery tasks before and after meditation. Their performance was compared with that of control groups, who either rested or performed other visuospatial tasks between testing sessions. The results indicate that all the groups performed at the same baseline level, but after meditation, Deity Yoga practitioners demonstrated a dramatic increase in performance on imagery tasks compared with the other groups. The results suggest that Deity meditation specifically trains one's capacity to access heightened visuospatial processing resources, rather than generally improving visuospatial imagery abilities.
Meditation and flexibility of visual perception and verbal problem solving (Dillbeck, 1982)
This study investigates the effects of the regular practice of the Transcendental Meditation (TM) technique on habitual patterns of visual perception and verbal problem solving. Subjects began the TM technique, relaxed, or added nothing to their daily schedule for 2-week periods. In addition to generalized effects of the interventions, the immediate effects of the TM technique, relaxation, and reading were compared on a letter perception task. The TM group improved scores for tasks of tachistoscopic identification of card and letter-sequence stimuli, but not for the verbal problem solving task of anagram solution.
Longitudinal Effects of the Transcendental and TM-Sidhi Program on cognitive Ability and Cognitive Style (Dilbeck, Assimakis, Orme-Johnson and Rowe, 1986)
Fifty college students practicing both transcendental meditation and a TM-Sidhi program (another type of meditation) were administered cult fair intelligence test and group embedded figures test. Significant longitudinal improvements over a 3 to 5 year period were observed in both tests.
Meditation and attention regulation (Jhansi and Krishna, 1996)
This study investigated whether the practice of transcendental meditation (TM), a cognitive exercise involving internal attention improves attention regulation capacity in its practitioners. 11 male and 8 female 9–11 yr olds who practiced transcendental meditation (TM) as part of their school curriculum were compared to 20 age and sex matched controls on their attention regulation capacity as measured by the Star Counting Test. Analysis of the data indicated that TM practitioners have greater attention regulation capacity than the control group.
The Impact of Intensive Mindfulness Training on Attentional Control, Cognitive Style, and Affect (Chambers et al, 2008)
To evaluate the impact of an intensive period of mindfulness meditation training on cognitive and affective function, a non-clinical group of 20 novice meditators were tested before and after participation in a 10-day intensive mindfulness meditation retreat. They were evaluated with self-report scales measuring mindfulness, rumination and affect, as well as performance tasks assessing working memory, sustained attention, and attention switching. Results indicated that those completing the mindfulness training demonstrated significant improvements in self-reported mindfulness, depressive symptoms, rumination, and performance measures of working memory and sustained attention, relative to a comparison group who did not undergo any meditation training.
Age effects on gray matter volume and attentional performance in Zen meditation (Pagnoni and Cekic, 2007)
Thirteen regular practitioners of zen meditation and 13 matched controls underwent sustained computerized attentional tasks and had their gray matter volumes analysed in an MRI machine. The control group demonstrated a correlation between gray matter volume and attention ability. This was not observed in the meditation group which had improved attentional abilities and more gray matter in the region of the brain known as the putamen. This region is generally associated with attention.
The underlying anatomical correlates of long-term meditation: Larger hippocampal and frontal volumes of gray matter (Luders, Toga, Lepore and Gaser, 2008)
Using high-resolution MRI data of 44 subjects, the study set out to examine the underlying anatomical correlates of long-term meditation. The study detected significantly larger gray matter volumes in meditators in the right orbito-frontal cortex (as well as in the right thalamus and left inferior temporal gyrus when co-varying for age and/or lowering applied statistical thresholds). In addition, meditators showed significantly larger volumes of the right hippocampus. Both orbito-frontal and hippocampal regions have been implicated in emotional regulation and response control.
Investigation of mindfulness meditation practitioners with voxel-based morphometry (Holzel et al, 2007)
This study investigated MRI brain images of 20 mindfulness (Vipassana) meditators (mean practice 8.6 years; 2 h daily) and compared the regional gray matter concentration to that of non-meditators matched for sex, age, education and handedness. Results confirmed greater gray matter concentration for meditators in the right anterior insula, which is involved in interoceptive awareness. This group difference presumably reflects the training of bodily awareness during mindfulness meditation. Furthermore, meditators had greater gray matter concentration in the left inferior temporal gyrus and right hippocampus. Both regions have previously been found to be involved in meditation. The mean value of gray matter concentration in the left inferior temporal gyrus was predictable by the amount of meditation training, corroborating the assumption of a causal impact of meditation training on gray matter concentration in this region.
Meditation Effects on Cognitive Function and Cerebral Blood Flow in Subjects with Memory Loss: A Preliminary Study (Newberg et al, 2010)
Fourteen subjects with memory problems underwent an 8 week meditation program. Brain scans were completed both before, during and after the meditation programs while neuropsychological test were performed before and after. The meditation program resulted in significant increases (p< 0.05) in baseline cerebral blood flow ratios in the prefrontal, superior frontal, and superior parietal cortices. Scores on neuropsychological tests of verbal fluency, Trails B, and logical memory showed improvements after training.
Neural correlates of attentional expertise in long-term meditation practitioners (Brefczynski-Lewis et al, 2007)
Meditation refers to a family of mental training practices that are designed to familiarize the practitioner with specific types of mental processes. One of the most basic forms of meditation is concentration meditation, in which sustained attention is focused on an object such as a small visual stimulus or the breath. In age-matched participants, using functional MRI, we found that activation in a network of brain regions typically involved in sustained attention showed an inverted u-shaped curve in which expert meditators (EMs) with an average of 19,000 h of practice had more activation than novices, but EMs with an average of 44,000 h had less activation. In response to distracter sounds used to probe the meditation, EMs vs. novices had less brain activation in regions related to discursive thoughts and emotions and more activation in regions related to response inhibition and attention. Correlation with hours of practice suggests possible plasticity in these mechanisms.
Most beneficial for - Anyone.
Effective dose - Benefits reported with mindfulness, transcendental and concentrative styles.
Length of action - Benefits reported after a single session but continue to improve with practice.
Safety - No adverse effects reported.
Type cognition effected - visuo-spatial processing, working memory, executive functioning, attention, cognitive flexibility and mental fatigue.
Enhancers - not known
Supporting Human Studies
Mindfulness Meditation Improves Cognition: Evidence of Brief Mental Training (Zeidan, Johnson, Diamond, David and Goolkasian, 2010)
This study examined whether brief mindfulness meditation training affects cognition and mood. Participants with no former mediation experiences were assigned 4 meditation sessions or a control group (listening to an audiobook). At the end of these sessions both groups underwent tests for mood, verbal fluency, visual coding and working memory. Mood improved in both groups however only the meditation group showed reduced fatigue, anxiety and increased mindfulness. The meditation also significantly improved visuo-spatial processing, working memory and executive functioning.
Meditation, Mindfulness and Cognitive Flexibility (Moore and Malinowski, 2009)
This study investigated the link between meditation, self-reported mindfulness and cognitive flexibility as well as other attentional functions. It compared a group of meditators experienced in mindfulness meditation with a meditation-naïve control group on measures of Stroop interference and the “d2-concentration and endurance test”. Overall the results suggest that attentional performance and cognitive flexibility are positively related to meditation practice and levels of mindfulness. Meditators performed significantly better than non-meditators on all measures of attention. Furthermore, self-reported mindfulness was higher in meditators than non-meditators and correlations with all attention measures were of moderate to high strength. This pattern of results suggests that mindfulness is intimately linked to improvements of attentional functions and cognitive flexibility.
Meditation and attention: A comparison of the effects of concentrative and mindfulness meditation on sustained attention (Valentine and Sweet, 1999)
The performance of concentrative and mindfulness meditators on a test of sustained attention (Wilkins' counting test) was compared with controls. Both groups of meditators demonstrated superior performance on the test of sustained attention in comparison with controls, and long-term meditators were superior to short-term meditators. Mindfulness meditators showed superior performance in comparison with concentrative meditators when the stimulus was unexpected but there was no difference between the two types ofmeditators when the stimulus was expected.
Mindfulness training modifies subsystems of attention (Jha et al, 2007)
This study investigates the hypothesis that mindfulness training may alter or enhance specific aspects of attention. It examined three functionally and neuroanatomically distinct but overlapping attentional subsystems: alerting, orienting, and conflict monitoring. Functioning of each subsystem was measured by performance on the Attention Network Test. Two types of mindfulness training (MT) programs were examined, and behavioral testing was conducted on participants before (Time 1) and after (Time 2) training. One training group consisted of individuals naive to mindfulness techniques who participated in an 8-week mindfulness-based stress reduction (MBSR) course that emphasized the development of concentrative meditation skills. The other training group consisted of individuals experienced in concentrative meditation techniques who participated in a 1-month intensive mindfulness retreat. Performance of these groups was compared with that of control participants who were meditation naive and received no MT. At Time 1, the participants in the retreat group demonstrated improved conflict monitoring performance relative to those in the MBSR and control groups. At Time 2, the participants in the MBSR course demonstrated significantly improved orienting in comparison with the control and retreat participants. In contrast, the participants in the retreat group demonstrated altered performance on the alerting component, with improvements in exogenous stimulus detection in comparison with the control and MBSR participants. The groups did not differ in conflict monitoring performance at Time 2.
Three Randomised Experiments on the Longitudinal Effects of the Transcendental Meditation Technique on Cognition (So and Orme-Johnson, 2001)
Three studies on 362 high school students at three different schools in Taiwan tested the hypothesis that regular practice of the Transcendental Meditation (TM) technique for 15–20 min twice a day for 6 to 12 months would improve cognitive ability. The students completed test for Creative Thinking-Drawing Production, Constructive Thinking Inventory, Group Embedded Figures Test, State and Trait Anxiety, Inspection Time and Culture Fair Intelligence Test. Univariate testing showed that TM practice produced significant effects on all variables compared to no-treatment controls. Napping for equivalent periods of time as TM practice had no effect. Contemplation meditation improved inspection time and embedded figures, but not the other variables. The TM technique was superior to contemplation meditation on five variables.
Short-term meditation training improves attention and self-regulation (Tang et al, 2007)
This article shows that a group randomly assigned to 5 days of meditation practice with the integrative body–mind training method shows significantly better attention and control of stress than a similarly chosen control group given relaxation training. The training method comes from traditional Chinese medicine and incorporates aspects of other meditation and mindfulness training. Compared with the control group, the experimental group of 40 undergraduate Chinese students given 5 days of 20-min integrative training showed greater improvement in conflict scores on the Attention Network Test, lower anxiety, depression, anger, and fatigue, and higher vigor on the Profile of Mood States scale, a significant decrease in stress-related cortisol, and an increase in immunoreactivity.
Investigating the impact of mindfulness meditation training on working memory: A mathematical modeling approach (van Vugt and Jha, 2011)
This study investigated whether mindfulness training (MT) influences information processing in a working memory task with complex visual stimuli. Participants were tested before (T1) and after (T2) participation in an intensive one-month MT retreat, and their performance was compared with that of an age- and education-matched control group. Accuracy did not differ across groups at either time point. Response times were faster and significantly less variable in the MT versus the control group at T2. Since these results could be due to changes in mnemonic processes, speed–accuracy trade-off, or nondecisional factors (e.g., motor execution), we used a mathematical modeling approach to disentangle these factors. The EZ-diffusion model suggested that MT leads to improved information quality and reduced response conservativeness, with no changes in nondecisional factors. The noisy exemplar model further suggested that the increase in information quality reflected a decrease in encoding noise and not an increase in forgetting.
Effects of Level of Meditation Experience on Attentional Focus: Is the Efficiency of Executive or Orientation Networks Improved? (Chan and Woolacott, 2007)
Participants (50 meditators and 10 controls) were given the Stroop (measures executive attention) and Global-Local Letters (measures orientational attention) tasks. Results showed that meditation experience was associated with reduced interference on the Stroop task (p < 0.03), in contrast with a lack of effect on interference in the Global-Local Letters task. This suggests that meditation produces long-term increases in the efficiency of the executive attentional network (anterior cingulate/prefrontal cortex) but no effect on the orientation network (parietal systems). The amount of time participants spent meditating each day, rather than the total number of hours of meditative practice over their lifetime, was negatively correlated with interference on the Stroop task (r = −0.31, p < 0.005).
Perceptual Discrimination and Sustained Attention (MacLean et al, 2010)
The ability to focus one’s attention underlies success in many everyday tasks, but voluntary attention cannot be sustained for extended periods of time. In the laboratory, sustained-attention failure is manifest as a decline in perceptual sensitivity with increasing time on task, known as the vigilance decrement. We investigated improvements in sustained attention with training (~5 hr/day for 3 months), which consisted of meditation practice that involved sustained selective attention on a chosen stimulus (e.g., the participant’s breath). Participants were randomly assigned either to receive training first (n = 30) or to serve as waiting-list controls and receive training second (n = 30). Training produced improvements in visual discrimination that were linked to increases in perceptual sensitivity and improved vigilance during sustained visual attention. Consistent with the resource model of vigilance, these results suggest that perceptual improvements can reduce the resource demand imposed by target discrimination and thus make it easier to sustain voluntary attention.
Meditation Experience is Associated with Increased Cortical Thickness (Lazar et al, 2006)
Magnetic resonance imaging was used to assess cortical thickness in 20 participants with extensive Insight meditation experience, which involves focused attention to internal experiences. Brain regions associated with attention, interoception and sensory processing were thicker in meditation participants than matched controls, including the prefrontal cortex and right anterior insula. Between-group differences in prefrontal cortical thickness were most pronounced in older participants, suggesting that meditation might offset age-related cortical thinning.
The Enhancement of Visuospatial Processing Efficiency Through Buddhist Deity Meditation (Kozhevnikov et al, 2009)
This study examined the effects of meditation on mental imagery, evaluating Buddhist monks' reports concerning their extraordinary imagery skills. Practitioners of Buddhist meditation were divided into two groups according to their preferred meditation style: Deity Yoga (focused attention on an internal visual image) or Open Presence (evenly distributed attention, not directed to any particular object). Both groups of meditators completed computerized mental-imagery tasks before and after meditation. Their performance was compared with that of control groups, who either rested or performed other visuospatial tasks between testing sessions. The results indicate that all the groups performed at the same baseline level, but after meditation, Deity Yoga practitioners demonstrated a dramatic increase in performance on imagery tasks compared with the other groups. The results suggest that Deity meditation specifically trains one's capacity to access heightened visuospatial processing resources, rather than generally improving visuospatial imagery abilities.
Meditation and flexibility of visual perception and verbal problem solving (Dillbeck, 1982)
This study investigates the effects of the regular practice of the Transcendental Meditation (TM) technique on habitual patterns of visual perception and verbal problem solving. Subjects began the TM technique, relaxed, or added nothing to their daily schedule for 2-week periods. In addition to generalized effects of the interventions, the immediate effects of the TM technique, relaxation, and reading were compared on a letter perception task. The TM group improved scores for tasks of tachistoscopic identification of card and letter-sequence stimuli, but not for the verbal problem solving task of anagram solution.
Longitudinal Effects of the Transcendental and TM-Sidhi Program on cognitive Ability and Cognitive Style (Dilbeck, Assimakis, Orme-Johnson and Rowe, 1986)
Fifty college students practicing both transcendental meditation and a TM-Sidhi program (another type of meditation) were administered cult fair intelligence test and group embedded figures test. Significant longitudinal improvements over a 3 to 5 year period were observed in both tests.
Meditation and attention regulation (Jhansi and Krishna, 1996)
This study investigated whether the practice of transcendental meditation (TM), a cognitive exercise involving internal attention improves attention regulation capacity in its practitioners. 11 male and 8 female 9–11 yr olds who practiced transcendental meditation (TM) as part of their school curriculum were compared to 20 age and sex matched controls on their attention regulation capacity as measured by the Star Counting Test. Analysis of the data indicated that TM practitioners have greater attention regulation capacity than the control group.
The Impact of Intensive Mindfulness Training on Attentional Control, Cognitive Style, and Affect (Chambers et al, 2008)
To evaluate the impact of an intensive period of mindfulness meditation training on cognitive and affective function, a non-clinical group of 20 novice meditators were tested before and after participation in a 10-day intensive mindfulness meditation retreat. They were evaluated with self-report scales measuring mindfulness, rumination and affect, as well as performance tasks assessing working memory, sustained attention, and attention switching. Results indicated that those completing the mindfulness training demonstrated significant improvements in self-reported mindfulness, depressive symptoms, rumination, and performance measures of working memory and sustained attention, relative to a comparison group who did not undergo any meditation training.
Age effects on gray matter volume and attentional performance in Zen meditation (Pagnoni and Cekic, 2007)
Thirteen regular practitioners of zen meditation and 13 matched controls underwent sustained computerized attentional tasks and had their gray matter volumes analysed in an MRI machine. The control group demonstrated a correlation between gray matter volume and attention ability. This was not observed in the meditation group which had improved attentional abilities and more gray matter in the region of the brain known as the putamen. This region is generally associated with attention.
The underlying anatomical correlates of long-term meditation: Larger hippocampal and frontal volumes of gray matter (Luders, Toga, Lepore and Gaser, 2008)
Using high-resolution MRI data of 44 subjects, the study set out to examine the underlying anatomical correlates of long-term meditation. The study detected significantly larger gray matter volumes in meditators in the right orbito-frontal cortex (as well as in the right thalamus and left inferior temporal gyrus when co-varying for age and/or lowering applied statistical thresholds). In addition, meditators showed significantly larger volumes of the right hippocampus. Both orbito-frontal and hippocampal regions have been implicated in emotional regulation and response control.
Investigation of mindfulness meditation practitioners with voxel-based morphometry (Holzel et al, 2007)
This study investigated MRI brain images of 20 mindfulness (Vipassana) meditators (mean practice 8.6 years; 2 h daily) and compared the regional gray matter concentration to that of non-meditators matched for sex, age, education and handedness. Results confirmed greater gray matter concentration for meditators in the right anterior insula, which is involved in interoceptive awareness. This group difference presumably reflects the training of bodily awareness during mindfulness meditation. Furthermore, meditators had greater gray matter concentration in the left inferior temporal gyrus and right hippocampus. Both regions have previously been found to be involved in meditation. The mean value of gray matter concentration in the left inferior temporal gyrus was predictable by the amount of meditation training, corroborating the assumption of a causal impact of meditation training on gray matter concentration in this region.
Meditation Effects on Cognitive Function and Cerebral Blood Flow in Subjects with Memory Loss: A Preliminary Study (Newberg et al, 2010)
Fourteen subjects with memory problems underwent an 8 week meditation program. Brain scans were completed both before, during and after the meditation programs while neuropsychological test were performed before and after. The meditation program resulted in significant increases (p< 0.05) in baseline cerebral blood flow ratios in the prefrontal, superior frontal, and superior parietal cortices. Scores on neuropsychological tests of verbal fluency, Trails B, and logical memory showed improvements after training.
Neural correlates of attentional expertise in long-term meditation practitioners (Brefczynski-Lewis et al, 2007)
Meditation refers to a family of mental training practices that are designed to familiarize the practitioner with specific types of mental processes. One of the most basic forms of meditation is concentration meditation, in which sustained attention is focused on an object such as a small visual stimulus or the breath. In age-matched participants, using functional MRI, we found that activation in a network of brain regions typically involved in sustained attention showed an inverted u-shaped curve in which expert meditators (EMs) with an average of 19,000 h of practice had more activation than novices, but EMs with an average of 44,000 h had less activation. In response to distracter sounds used to probe the meditation, EMs vs. novices had less brain activation in regions related to discursive thoughts and emotions and more activation in regions related to response inhibition and attention. Correlation with hours of practice suggests possible plasticity in these mechanisms.