Holzel et al.
(mindfulness
and brain scans)
Asim Masood
asimmm196@gmail.com
+923002626209
PSYCHOLOGY BEING INVESTIGATED
Localisation of function: the way particular brain areas are responsible for
different activities, for example, the hippocampus is associated with memory
and emotion regulation. It can be investigated through brain scanning
techniques such as functional and structural brain scans (FMRI and MRI scans)
Mindfulness: a stress reduction technique used to improve well-being. It is a
state achieved through meditation that aims to increase awareness of the
present-moment experience, and enable a person to look at themselves in a
compassionate, non-judgmental way
BACKGROUND
Holzel focused on the effects of a particular mindfulness technique called
MBSR developed by Professor Kabat-Zinn
The technique includes an eight-week program with 2.5 hour weekly group
meetings, plus one 6.5 hour training day
Group meetings include training in three techniques (body scanning, mindful
yoga, and sitting meditation) that members are encouraged to build into
their everyday lives
Previous studies have shown that experienced meditators have significantly
more grey matter in certain areas of the brain compared to non-meditators
The two areas that are focused on in particular are the hippocampus and the
insula
In one particular study, participants meditated while in an fMRI scanner, and
the scans showed high activity in the hippocampus
Some longitudinal studies have also shown that grey matter increases in key
brain structures when people learn new knowledge or skills, which suggests
that changes in well-being may be linked to increases in grey matter
Grey matter is a type of tissue in the brain and spinal cord that plays a crucial role in
allowing one to think, learn and control their body
It contains billions of nerve cells (neurons) that send and receive signals that allow us
to process information and make sense of the world around us
Different parts of grey matter handle different tasks, for instance, some parts are
responsible for things like memory, learning, and emotions, while others control
movement and coordination of our muscles
White matter, on the other hand, are bundles of nerve fibers called axons, which
extend from one neuron to another, forming connections that allow signals to be sent
to one another
In simple terms, grey matter is responsible for processing and thinking, while white
matter makes sure these processed signals are sent to the right places in the brain
AIM
To identify changes in specific brain regions, and the whole brain,
by comparing grey matter concentration before and after a
mindfulness course
METHOD AND DESIGN
Research Method Technique:
Experimental: a causal relationship was tested between MBSR and grey matter
concentration in various brain structures. Some measurements were taken in a controlled
setting (MRI scans), but other parts of the study occurred in a naturalistic environment,
such as incorporating MBSR exercises while walking and doing housework
Longitudinal: a group of participants was tested before (pre) and after (post) an
intervention. The total duration was an eight-week period
Correlation: a non causal relationship was tested between time spent on mindfulness
exercises and increases in grey matter concentration
Self-report: The Five Facets of Mindfulness Questionnaire (FFMQ)
Independent Variable:
1. Whether participants received MBSR (experimental condition) or not (control condition)
2. Data collection time – operationalized by beginning or end of the eight week study
period
Dependent Variable:
1. Grey matter concentration in specific brain structures – operationalized by using voxel-
based morphometry
2. Five facets of mindfulness – operationalized by the FFMQ
3. Time spent on mindfulness exercises between weekly sessions – operationalized by
recording in a daily diary
Experimental Design: Independent measures design
Sampling Method: Opportunity Sample
SAMPLE
33 (initially 35) right handed, healthy adults, aged 25-55 years
Recruited from four MBSR courses held at the Center for Mindfulness at the
University of Massachusetts Medical School
Participants enrolled to help with stress reduction either because they had
chosen to attend the course, or had been referred by their doctor
Individuals were included in the study if they self-reported as physically and
psychologically healthy and not taking any medications
Further inclusion criteria was:
No meditation classes in the past 6 months
No more than four classes in the past 5 years, or 10 classes in their lifetime
No contradictions for MRI scanning (metallic implants, claustrophobia)
Commitment to attend all eight classes and complete the daily homework
Initially, the sample consisted of 8 males and 10 females, which fell to 6
males and 10 females as two males left after the first MRI session due to
discomfort
The remaining sample had a mean age of 38 years and included 13 Caucasian,
1 Asian, 1 African American, and 1 multi-ethnic participant
Participants had an average 17.7 years of education
The control group consisted of 11 males and 6 females with a mean age of 39 years
They had an average of 17.3 years of education
They included 13 Caucasians, 2 Asians, 2 African Americans, and 1 Hispanic participant
Written consent was obtained from all 33 participants
Both the MBSR and the control groups did not differ in terms of age or education, and the
control group has the same eligibility criteria as the experimental group, and therefore, are
referred to as a ‘wait-list’ control group
All participants received a discounted MBSR course fee for participation
APPARATUS
PROCEDURE
Both the experimental and control groups were required to complete the Five
Facet Mindfulness Questionnaire (FFMQ)
The questionnaire includes 39 items that measure:
Observing: attending to/noticing internal and external stimuli such as thoughts,
sensations, smells, sounds etc.
Describing: mentally labelling these observations with words
Acting with awareness: being attentive to current actions rather than responding
absentmindedly
Non-Judging: not evaluating sensations, cognitions, or emotions
Non-Reactivity: allowing thoughts and feelings to drift in and out
Responses to the items are given on a 5-point Likert scale (1 = never or very rarely
true, 5 = very often or always true)
A mindful participant would perhaps choose the option ‘Very often or always true (5)’
for an item such as ‘I’m good at finding words to describe my feelings’
Some items were ‘reversed scored’, which means that a mindful participant would
select the option ‘Never or very rarely true (5)’ for an item such as ‘I am easily
distracted’. In this case, the option of ‘Never or very rarely true’ would be given a
score of 5 rather than 1, as it indicates a mindful response for this particular item
The total score for each of the 5 categories/subscales are added up for a total FFMQ
score
Useable data was collected from 14 participants from each group
MRI scans were conducted two weeks before the experimental group had their first
MBSR training
3D models were created of the brain by taking pictures of 128 sagittal slices (top of
the brain to the bottom), and combining these pictures using a computer software
These models were then analysed using voxel-based morphometry (VBM), a technique
of segmenting the brain into grey matter and white matter, in order to measure grey
matter concentration in the two brain ‘regions of interest’ (ROI) – the bilateral
hippocampi and insulae, as well as the brain as a whole
The experimental group then took part in an 8 weekly MBSR sessions, after which
they completed the FFMQ
Sessions took place at the Center for Mindfulness at the University of Massachusetts
Medical School
The experimental group participants were given a 45 minute audio recording of
guided mindfulness exercises including body scan, yoga, and meditation, to help
them complete exercises at home such as washing up, eating, or taking a shower
Further MRI scans were taken two weeks after the final MBSR session for the
experimental group
The approximate duration between the pre-test (first scan) and post-test (second
scan) was 56 days
The control group also took two scans, 66 days apart, as well as completing the FFMQ
once after the first scan, and once again after the second scan
The eight-week program of MBSR that included 2.5 hour weekly group meetings, plus
one 6.5 hour training day involved training in three techniques:
1. Body Scanning: slowly becoming aware of sensations in each area of the body, which in
turn leads to gradually developing awareness of the whole body/mind
2. Mindful Yoga: gentle stretching, coordinated, slow movements and breathing with a
focus on the moment to moment experience. This training allows one to be fully aware
of their presence in the here-and-now and the development of self-compassion with an
awareness and acceptance of the body’s potential and limitations
3. Sitting Meditation: developing awareness of the sensation of breathing and of sensory
information such as sight, smell, touch, taste etc, and emotions. This allows for a
gradual awareness of all aspects of consciousness
CONTROLS
All participants took the same standardized FFMQ, once before the session,
and once after
The FFMQ was scored on a standardized rating scale
All participants in the experimental group went through the same MBSR
training for the same duration
The use of the MRI was standardized, and scans were always taken two weeks
before the training program, and two weeks after
RESULTS
The experimental group had an average of 22.6 hours of MBSR exercises, with
a standard deviation of 6.3 hours, suggesting that some participants practiced
considerably more than others
Overall, participants spent approximately 27 minutes per day on mindfulness
homework during the course
Most time was spent on body scanning, almost twice as much on this
compared to yoga or meditation
There were no significant correlations between any of the individual
exercises
For example, the correlation coefficient between body scanning and sitting
meditation was –0.26, where as for yoga and sitting meditation, it was 0.49, and for
body scan and yoga it was -0.042
This suggests that different people preferred different exercises, but doing a lot of
one particular exercise did not necessarily mean they did a lot of either of the two
With regards to improvement in mindfulness, the FFMQ showed that the experimental
group had a significant improvement from pre-test to post-test scores in ‘acting with
awareness’, ‘observing’, and ‘non-judging’ after MBSR compared to the control
group, however, they did not show improvements in ‘describing’, or ‘non-reactivity’
This useable data from the FFMQ was obtained from 14 MBSR and 14 control
participants
There were no differences between the two groups at the start of the study, nor
were there any changes in grey matter concentration in the control group between
the two test points
With regards to grey matter changes, the experimental group experienced a
significant increase in grey matter concentration in their left hippocampus, and for
whole brain analysis – in the posterior cingulate cortex, temporo-parietal junction,
and cerebellum compared to the control group
Changes in the cerebellum were observed in two locations, one of which was the
brainstem, and the other the lateral cerebellum
However, unlike in previous research, no significant difference was found in grey
matter concentration in the insulae before and after MBSR
Grey matter concentration was not correlated with the amount of time spent
engaged in mindfulness exercises or changes on the FFMQ
This suggests that time spent on mindfulness is not as important as regularly
practicing it is
No parts of the brain showed decrease in grey matter concentration from the MBSR
program, however, the control group did show a decrease in the posterior cingulate
cortex
CONCLUSION
Structural changes in the ROI such as the left hippocampus shows an increase in grey
matter concentration after an eight-week participation in MBSR
These structural changes are also observed in other brain regions such as the
posterior cingulate cortex, temporal-parietal junction, and cerebellum
As the hippocampus plays a role in learning and memory, the participants who took
the MBSR course had learning experiences that changed the hippocampal grey
matter
The study did not confirm previous research findings relating to the insula, and
therefore, perhaps changes in this region may require more than eight weeks of
practice
NATURE VS NURTURE DEBATE
The study supports the nature side of the debate
The results can be supported by biological factors such as structural
plasticity, or in other words, changes in grey matter concentration in key
brain regions such as the left hippocampus
However, the nurture side can also be supported by the fact that the
participants went through an MBSR training program in which they learnt to
deal with stress in their lives, which in turn allowed them to improve their
wellbeing
INDIVIDUAL VS SITUATIONAL DEBATE
The study supports the individual explanation as participants were able to
choose their own exercises within the training, and this would impact
individuals differently, depending on the duration spent on particular
exercises, as well as the regularity of its practice
However, the situational explanation is also supported, as it was the situation
of participants receiving MBSR training that lead to an increase in grey matter
concentration, which in turn, improved their wellbeing, whereas those in the
control group, who had no such training, did not see any increase in grey
matter concentration during the same period
APPLICATION TO EVERYDAY LIFE
People can apply MBSR exercises to help reduce their stress levels and
improve their mental and physical wellbeing
Organisations can incorporate MBSR training sessions for their employees who
may be experiencing high levels of work place stress
By implementing MBSR or mindfulness exercises, individuals can regulate
their emotions and cognitions for healthier psychological functioning
EVALUATION
RELIABILITY
Strength: The study has high levels of controls, for example, the duration of
the MBSR training was the same (eight-week long course), and all participants
administered the same FFMQ, and were scanned through the same MRI
scanner, which makes the procedure standardized and easy to replicate to
test for reliability
Weakness: The exercises the participants engaged in were not standardized,
as some individuals may have spent more time on certain exercises compared
to others, and at different locations (office, home etc.), which lowers the
standardization of the procedure, making it difficult to replicate for
reliability
VALIDITY
Strength: The study did have controls over confounding variables. They
ensured the participants did not receive any mindfulness training in the past
6 months, and excluded those who metallic implants or claustrophobia, which
would influence the results. This made the researcher more confident of the
IV of the MBSR training being the main reason for increase in grey matter
concentration, which was the DV, hence increasing validity.
Weakness: The participants had to complete the FFMQ, and there are chances
of providing socially desirable responses, which may reduce the validity of
their scores
GENERALISABILITY
Strength: The sample was diverse as it included both males and females, and
of different ethnicities such as Caucasians, African-Americans, Asians,
Hispanics etc., and also included people aged 25 – 55 years
Weakness: Overall, the generalisability of the sample is low as the sample
size of 33 participants is small, with a relatively high level of formal
education (mean 17.5 years). It includes only right handed individuals, and
therefore, cannot be applied to left handed participants, or to the elderly, or
even children or teenage participants
ECOLOGICAL VALIDITY
Strength: As the participants were practicing the mindfulness exercises in
their natural everyday life settings such as at home or at their offices, the
study has ecological validity. Furthermore, people do experience stress in
their everyday lives and engage in meditation such as mindfulness exercises
in order to improve their wellbeing, and therefore, the study has high
mundane realism
ETHICS
Strength: The participants knew the real aim of the experiment and
therefore, were debriefed about the purpose of the study
Strength: The participants had the right to withdraw as two male
participants withdrew from the study after feeling uncomfortable
Strength: The confidentiality of the participants was maintained as no one’s
identity or personal information such as where they work, was revealed
ETHICS
Strength: Some of the participants enrolled in the course themselves, and
therefore provided informed consent
Strength: Participants were protected from psychological and physical harm,
as those with claustrophobia or metallic implants were excluded from the
study
Weakness: Some participants, however, may still have not been protected
from psychological harm, as two particular participants did feel discomfort
during the scanning part of the procedure
EXPERIMENTAL DESIGN
Strength: The study used an independent measures design as there were
different participants for the two levels of the IV (the MBSR experimental
group, and the control group). This ensures that any difference in grey
matter concentration or improvement in mental wellbeing, is due to the
mindfulness exercises as the results would be compared of the experimental
group to the control group, which would increase validity
Weakness: There can be individual differences as it is possible that some
participants may have chosen certain mindfulness exercises where they were
exposed to a larger social group, and perhaps it was this interaction with
others that lead to improvement in wellbeing, rather than the actual
exercises, which can lower validity. Furthermore, some individuals spent
more time on certain exercises than others, and practiced more regularly
than others as well
LONGITUDINAL STUDY
Strength: Detailed, in-depth data can be collected over a long time period,
which allows for development of behaviour to be studied overtime. In this
study, the participants’ changes in wellbeing was assessed after a period of
eight weeks, which allows us to study structural plasticity as a result of
mindfulness exercises, which increases validity
Weakness: There is a possibility of participant attrition, which is when
participants withdraw from a study, as it is at times not practical or possible
for all participants to remain in a study over a long time period, which can
lower the generalisability. In this study, two participants exercised their right
to withdraw
SELF REPORT
Strength: The FFMQ is a standardized questionnaire which can be replicated
to test for reliability
Strength: The FFMQ had a standardized scale through which participants
received scores, which would provide quantitative data that can be used for
comparisons
Weakness: There is a possibility of participants providing socially desirable
responses which can lower validity. Furthermore, the responses were close
ended, and this would restrict participants from providing more detailed,
open-ended responses, and as a result, lowers validity
DATA
Strength: The study collected quantitative data that is objective and
numerical and allows for comparisons to be made. The results of the study
showed that those who received mindfulness training had increased grey
matter concentration over a period of eight weeks in key brain regions,
compared to the control group
Weakness: The study lacked qualitative data as the data collected was
through a standardized scale for close ended questions
SAMPLING METHOD
Strength: Opportunity sample allows for participants to be acquired with
convenience, as they are readily available. In this study, some of the
participants had been referred to the course by doctors for stress reduction
Weakness: Through opportunity sampling, participants are usually acquired
from the same area and hence have similar characteristics, which can lower
the generalisability
