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The Blissful Brain: Neuroscience and proof of
the power of meditation
Dr Shanida Nataraja
Structure
General introduction
Bridging science and spirituality
Peering into the meditating brain
Health benefits of meditation
Structure
General introduction
Bridging science and spirituality
Peering into the meditating brain
Health benefits of meditation
The Human Brain
First mentioned in Edwin Smith Surgical Papyrus 1700 BC
Largely disregarded by the Egyptians
Aristotle proposed brain was cooling unit to lower blood temperature
Site of Human Intellect
Importance first noted by Hippocrates in 5th Century BC
Supported by Galen of Pergamum: dissections and surgeries on Roman gladiators
Confirmed by Thomas Willis (1621-1673): founding father of modern brain science
The Brain as a Black Box
The brain efficiently controls behavior so we can run on “auto-pilot”
The brain possesses astounding and unrivalled range of abilities
The brain
weighs about 1 ½ bags of sugar
has the consistency of blancmange
contains 100 billion neurons
is highly interconnected
A Dynamic Network
Each neuron is miniature processing unit
receiving information from other cells
processing information
relaying resulting data to other cells
Every person has unique configuration
Precise wiring of all the connections in the brain is continually changing, adapting with experience
Brain Complexity
When examined under microscope, brain tissue appears as tangled mess
Closer examination reveals it to be highly ordered
Cells with similar structure and function arranged in layers with common orientation
Hierarchal Structure of Brain
Hindbrain, midbrain, and forebrain
Newer brain regions laid on top of older regions
Older useful circuitry incorporated into newer, more advanced circuitry
The Cerebral Cortex
Particularly predominant in humans
Highly folded external appearance
Mediate all of the cognitive skills associated with being human
Can be divided into four lobes: frontal; temporal; parietal; and occipital
Cerebral Lobes
Left Brain vs. Right Brain
Both hemisphere have similar functions with respect to sensory processing and motor function
In other respects, the function of the two hemispheres is asymmetrical
The left hemisphere is associated with analytical, rational, and logical processing
The right hemisphere is associated with abstract thought, nonverbal awareness, visual–spatial perception, and emotions
Reality or Fantasy?
Right hemisphere: more realistic impression of particular sensory
experience
intuitively examines experience and stores it as images and emotions
Left hemisphere: filters and rationally analyses the experience
stores it as a mental map
influenced by the individual’s experiences in the past (i.e. their conditioning)
Thalamus and the Senses
Gateway for sensory information flowing into cortex
Where sensations are first consciously experienced
Important role in attention
Gateway for motor information flowing into cortex
Important role in motor intention
Hypothalamus
Maintains constant internal environment
Modulates emotional responses with other limbic structures
Regulates arousal through action on autonomic nervous system
Hypothalamus
Pituitary Gland
Autonomic NervousSystem
Autonomic Nervous System
Sympathetic (“fight or flight” responses): increases heart rate and breathing rate; slows digestion; dilates pupils
Parasympathetic (“rest and digest” responses) nervous systems: decreases heart rate and breathing rate; stimulates digestion
Structure
General introduction
Bridging science and spirituality
Peering into the meditating brain
Health benefits of meditation
Religion versus Science
Assumed that reality could be given a single, complete, and unambiguous description in human language
Neither Science nor Religion alone can provide a complete description
Science and Spirituality
1997 survey of US scientists revealed 40% believed in a personal God
Quantum pioneers, including Einstein and Bohr, have been described as mystics
Importance of the integration of scientific and spiritual knowledge
Complementary aspects of a greater whole, each capturing a differing and partial representation of a greater reality
Neurotheology
Patients with temporal lobe epilepsy
Have hallucinations with a religious content
Have seizure-induced feelings of religious ecstasy
Report spontaneous religious conversions
There is even evidence that some mystics may have had temporal lobe epilepsy
The “God Module”
Ramachandran (1997) proposed that the temporal lobe played an important role in mystical and religious experiences
Media and scientists alike declared that “God module” had been found in the human brain
Persinger’s Helmet
Persinger proposes mystical experiences are result of microseizures in the deep structures of the temporal lobe
These are provoked by personal life crises and near-death experiences
An individual’s susceptibility to these microseizures depends on excitability of the temporal lobe
Healthy individuals, as well as epileptic patients, can also display these microseizures
Transcranial Magnetic Stimulation
Subjects stimulated by a weak magnetic field over the right hemisphere
Using a specially designed helmet of magnets
80% of subjects reported the sense of a presence
Artefacts of Brain Function
Persinger proposed “religion is a property of the brain, only the brain, and has little to do with what’s out there”
Taken as proof that God doesn’t exist; God and all religious thought are artefacts of brain function
Inherent limitations of scientific method ensure that we will never be able to definitively prove or disprove the existence of God
Mystically Hard-Wired
Stimulation of certain areas of the brain to evoke certain experiences is not best way of investigating these experiences
These artificial experiences can rightly be viewed as being artefacts of brain function
The artificial stimulation experiments merely reinforce belief that humans are hard-wired to be receptive to mystical or religious experiences
Subjectivity
Humankind has created a rigid conceptual map of our World that
acts as a framework to communicate details of our experiences to others
limits our ability to describe and understand our experiences
This mental map is formed by the cumulative experience of a person’s
lifetime
an imprint of all of our personal, societal, and cultural conditioning
Conceptual Map
Our conceptual map
Defines our goals and expectations
Dictates the way in which we perceive the world and our relationship to it
Provides an explanation for our experiences
Everyone’s conceptual map is slightly different
Structure
General introduction
Bridging science and spirituality
Peering into the meditating brain
Health benefits of meditation
Definition of Meditation
Countless different meditative techniques
Meditation
involves a specific technique that is both clearly defined and taught to the practitioner
involves, at some stage, progressive muscle relaxation
involves, at some stage, a reduction in logical processing
is self-induced
involves a skill, referred to as an anchor, that allows the practitioner to effectively focus their attention
Types of Meditation
Can be passive and active
Passive meditation
empties mind of thought and is attentive on entire experience, usually by using an anchor, such as the breath
involves a widening of attention and includes techniques such as mindfulness
Active meditation
focuses attention on a specific mantra or image
involves a narrowing of attention and includes techniques such as TM and Zen meditation
Expanding or Restricting Attention
Newberg and d’Aquili
Observed meditators in controlled conditions
Release of a radioactive tracer into the blood system triggered by meditator pulling on string
SPECT (single photon emission computed tomography): blood flow in different regions of the brain can be visualized
Transcendental Experiences
Associated with specific patterns of brain activity, in specific regions of the cerebral cortex
Key features
Increase in activity in frontal cortex: attention
Decrease in activity in parietal cortex: dissolving of self/non-self boundary
Frontal Cortex: Attention
Meditation begins with the intent to practice followed by a re-focusing of the attention
The intention of the practitioner to sit “meditate” triggers thalamus to re-focus the the attention either inwards or outwards
Focused attention acts to “clear the mind” through redundancy
Reflected in increase in activity in frontal cortex
Parietal Cortex: Orientation
Meditative practice associated with dissolving of self/non-self boundary
Meditation involves decrease in activity in region of brain that constructs our self/non-self boundary, in both the left and right hemisphere
This decrease can partially explain the expansion of awareness that can be experienced during meditation
Shift From Left to Right Brain
Effect on self/non-self boundary can also be understood in terms of initial shift in meditation from left to right brain activity
Left brain: ego-centered thinking
Right brain: holistic, non-ego thinking
Attention is a right brain function; focused attention thus involves shift from left to right brained thinking
Passive Meditation
Practitioner begins with intent to clear mind of thoughts
Then attention is focused on gap between thoughts or on the breath
Attention triggers shift to right brained activity
makes practitioner less aware of redundant sensory information and thoughts
Switch From Left to Right
Fundamental to the shift in thinking that accompanies contemplative practice
It also underlies the power of myths
All myths have a common framework
Existential question is posed: e.g. “How was the Universe created”
The issue raised is presented in terms of conflict between two apparently irreconcilable opposites: e.g. good–evil, life–death
A possible resolution is presented, usually in terms of the reconciliation of polar opposites
Myths and Brain Function
The first stage triggers activity in the left hemisphere; comprehension of language and the comparison of concepts are left-brained activities
The second stage triggers activity in the right hemisphere; comprehension of unity and reconciliation of polar opposites requires right-brained activity
The progression from first to second stage involves a switch between left- and right-brained thinking
A Quest for Meaning
Activity in the left hemisphere drives activity in the right hemisphere
The quest for meaning to our experiences triggers a shift in brain function that allows us to perceive the “big picture”
Passive Meditation
Practitioner thus becomes less aware of their orientation in the spatial dimensions and in time
Decrease sense of orientation is reflected in decreased activity in parietal lobe that leads to
a sense of no or infinite space and/or time
an inability to convey the experience efficiently through language
Simplified Meditation Process
Decrease in activity
Increase in activity
Activation of Limbic System
Activation of hippocampus
confers emotional value to experience
triggers the autonomic nervous system
Maximal activation of autonomic nervous system lead to
a blissful, peaceful state via parasympathetic system
and then a mentally clear and alert state via sympathetic system
Simplified Meditation Process
Decrease in activity
Increase in activity
1
3
2
1
1
Active Meditation
Practitioner begins with intent to clear mind of thoughts
Then attention is focused on single object, image, or mantra
Attention filters out redundant sensory information and thoughts
Activity in occipital and frontal lobes fixes object in practitioner’s mind
Simplified Meditation Process
Decrease in activity
Increase in activity
Active Meditation
Activation of hippocampus and autonomic nervous system
Peak response prompts hippocampus to dampen activity
This results in decrease in activity in parietal lobes and thus
sense of no or infinite space and/or time
a loss of the ability to comprehend the experience in rational terms
an inability to describe the experience using language
Simplified Meditation Process
Decrease in activity
Increase in activity
5
1
1
3
2
4
Important Features
Crucial role of intention
Role of thalamus in re-focusing attention
Role of attention in “clearing the mind”
Shift from left to right brain activity through sustained attention
Dependence of self/non-self boundary on activity predominantly in left parietal cortex
Widening of awareness and holistic thinking stemming from right-brained activity
Impact of meditation on body through activation of the arousal/relaxation systems
Electrical Brain Recordings
Electroencephalogram (EEG) is a non-invasive technique
Records combined electricity activity of large groups of neurons within the brain
In clinical practice, 19 electrodes are positioned on head
Different Brain Waves
Brain Wave Trace Frequency Subjective description
Delta 0.5 and 4 Hz Active thought, attention, or problem solving
Theta 4 and 7 Hz Creativity and imagination
Alpha 8 and 13 Hz Relaxation and the meditative state
Beta 13 and 30 Hz Intuitive thought, empathy, and instinctual insight
Wave Changes in Meditation
Early stages of meditation:
increase in alpha waves; state of relaxed alertness
decrease in beta waves; reduction in intrusive thoughts
During transcendental experiences: increase in theta waves; feelings of bliss
In deeper stages of meditation: some practitioners display high frequency beta or gamma waves; assembly of fragments of information into single, coordinated picture
Maxwell Cade
Proposed (1978) that different levels of consciousness could be correlated with different brain wave patterns
Meditative pattern involves absence of the beta waves and an increase in alpha and theta wave
Can be differentiated from lower states of consciousness by presence of multiple frequency bands (i.e. alpha and theta) rather than just one
Relaxation Response
Meditation superimposed on general relaxation response
Mediated by parasympathetic nervous system, this includes decrease in oxygen consumption
reduction in the elimination of carbon dioxide
a reduction in heart rate, respiratory rate, blood pressure, and lactate levels in the blood, muscle tone, and blood cortisone levels
increase in the blood flow to the internal organs
increase in the temperature of the fingers
increase in skin resistance
Facilitating Relaxation
Four different elements that facilitate the relaxation response during meditation
A mental device: shifts mind from logical and externally orientated, left-brained thinking to intuitive and internally orientated, right-brained thinking
A passive attitude: rating or judging the session can cause anxiety
A comfortable position: minimal muscular effort required to maintain an upright position without promoting sleep
Quiet environment: minimizes noises that may distract the practitioner or make them anxious
Variable EEG Signatures
Not possible to give one EEG signature relevant to all types of meditation or all individuals
Precise changes in the EEG recording differ depending on meditative technique used
Fundamental differences between different techniques are reflected in different EEG signatures
Structure
General introduction
Bridging science and spirituality
Peering into the meditating brain
Health benefits of meditation
Psychosomatic Disorders
Psychosomatic disorders (i.e. those that involve physical symptoms, but have an emotional or psychological origin)
Psoriasis, eczema, stomach ulcers, high blood pressure, and heart disease have all be shown to be triggered and exacerbated by psychological factors, such as stress and anxiety
In the West, the prevalence of psychosomatic diseases continues to increase in line with stress in our social environment
Neuroendocrine System
Neuroendocrine System
Stress can trigger long-term abnormalities in the neuroendocrine system
Individual is in state of permanent arousal; high cortisol levels
Stress can
impair memory and damage hippocampus (as in Cushing’s syndrome)
cause both depression and anxiety
compromise the immune system
Health Benefits of Meditation
Physiological effects of meditation differ
from one individual to the next
depending on the specific meditative technique used
Meditation has been associated with a number of important physical and mental health benefits
The size of benefit increases with more frequent meditative practice, and are most pronounced in experienced meditators
Frequently Cited Criticisms
Few studies use the same rigorous methods routinely used in studies of investigational pharmaceuticals
Studies have produced highly variable, and often conflicting results
Highly Variable Findings
It is difficult to accurately assess adherence to meditation program; it is impossible to provide participants a “fixed dose” of meditation
Meditation is an expansive term; it is therefore not valid to compare the findings of studies using different techniques
Subject differ psychologically, emotionally, and spiritually; it is therefore impossible to enrol a homogenous population
A specific meditative technique is not “for everyone”
Mindfulness-Based Stress Reduction
Technique first proposed by Jon Kabat-Zinn and his colleagues in 1979
Possible therapeutic option for patients suffering from physical, psychosomatic, and psychiatric disorders
Although taught independently of any religious or esoteric tradition, it is rooted in contemplative spiritual traditions
Trains practitioner to develop enhanced awareness of the moment-to-moment experience of emergent mental processes
Meditation and Stress
Meditation
decreases cortisol levels in healthy subjects and patients with cancer
lowers activity in the sympathetic system
reduces lipid peroxide content of the blood
reduces coronary prone behaviour
MBSR and Stress
MBSR investigated in a wide range of patients (pain, cancer, heart disease, depression, and anxiety)
Overall, studies indicate MBSR is effective method of stress reduction associated with benefits in terms of
overall health and
the ability of these patients to cope with their condition
MBSR and Stress
Carlson et al: improved overall QoL, stress symptoms, and sleep quality in breast and prostate cancer outpatients
Shapiro et al: reduced anxiety and psychological distress, including depression in med students
Roth et al: decreases need for primary care consultations
Kabat-Zinn et al: improves clearance of skin lesions in patients with psoriasis
Meditation and the GSR
Effects of meditation on arousal system can be detected as changes in the Galvanized Skin Response (GSR)
Measure of skin resistance related to cortical arousal High arousal = decreased resistance and GSR Low arousal = increased resistance and GSR
Meditation triggers increase in GSR that stabilizes in 5–10 min; mean increase was 17.5% in one study of 50 meditators
Meditation and Immune System
Cortisol suppresses immune system
Meditation Davidson et al: boosts immune response to a
vaccine
Solberg et al: reduces immune response to stress
Antoni et al: increases immune activity after 10 weeks in patients with HIV; the result of meditation on reducing stress levels and depression
Subjective Psychological Effects
Boost in energy levels
Increased self-acceptance
Release from tendency to self-blame
Increased acceptance of others
Increase ability to express emotions, both positive and negative
Less prone to bouts of irritability, impatience, and emotional or behavioural outbursts
Improved and expanded sense of identity
Meditation and Anxiety
Meditators tend to be slightly more neurotic and anxious than the general population
Long-term meditators less anxious than novice meditators and non-meditators
Novice meditators show significant decreases in anxiety after training
Meditators also report reduce levels of neuroticism; reduction is related to frequency of meditative practice
Meditation and Addiction
Meditation plays important role in treatment of addictive behaviour
Meditation reduces alcohol and nicotine consumption and use of illegal substances, tranquillizers, prescribed medications, and even caffeine
These reductions suggest decreased reliance on external means of
altering the physical and mental state
reflects reduction in attention given to the intrusive thoughts that elicits desire to consume addictive substance
Meditation and Coping Strategies
Promising supportive intervention for patients who need to learn coping mechanisms for chronic pain
Mindfulness of movement produced improvements in symptoms in patients with multiple sclerosis
Reduces psychological distress in patients with variety of chronic physical or psychosomatic disorders, including chronic fibromyalgia
Possible Adverse Effects of Meditation
Shapiro et al: possible adverse effects of meditation in 27 long-term meditators
About 2/3 of subjects reported at least one adverse effect, including
relaxation-induced anxiety and panic
decreased motivation
confusion and disorientation
Depression and feeling “spaced out”
The positive effects of meditation outweighed the negative effects
Increasing Awareness of Unconscious Behaviour
Galvanized Skin Response (GSR)
Psychophysiological response measured in skin containing sweat glands
GSR can be
visualised as a moving trace on a computer monitor
translated into an auditory tone
encoded in changes in the frequency of a flashing light or indeed the colour of that light
combined with computer gaming wizardry to allow the subject to play a video game
Interpreting the GSR
High level of arousal is indicated by a fall in skin resistance (and a drop in the GSR reading)
Low level of arousal or relaxation is reflected in an increase in skin resistance (and a rise in the GSR reading)
Neural processes remain undefined, but sympathetic nervous system is involved; opening of sweat glands in a state of “fight or flight” leads to fall in skin resistance, and thus drop in GSR meter reading
GSR Trace
Biofeedback and the ACC
The anterior cingulate cortex (ACC) is a small structure tucked in between the hemispheres
The ACC
is involved in decision-making and evaluating “how well things are going” after we make a particular decision
becomes activated during biofeedback
is intimately related to the sympathetic arousal system, playing a role in the intentional modulation of bodily arousal
Using Biofeedback
Primary interest has revolved around its ability to increase an individual’s awareness of unconscious, automated behaviour
Often individuals are unaware that they are in a constant state of arousal
Constant state of arousal gives rise to elevated stress levels, and thus a wide range of different stress-related diseases
Visualizing Physiological Changes
Individual can visualise physiological changes occurring to different stimuli, both external and internal
By visualising the effects of these stimuli on the level of arousal, the individual becomes consciously aware of these physiological responses
Conscious awareness of these responses permits the individual to bring arousal under voluntary control
How Does it Work?
The GSR displays information about physiological processes as a visual cue
The practitioner uses this cue to keep their arousal at a steady level and to change it at will
The individual learns to modify their behaviour to elicit a pre-defined goal
Control over the biofeedback instrument translates into control over arousal
With time, the individual can control arousal without the need for the visual cue
Using the GSR in Meditation
Relaxation plays an important role in the preparatory stages of meditation
Practice should begin with
a gradual and progression relaxation of the muscles of the body
an unforced and progressive quietening of the mind
Both physical and psychological elements lead to a reduction in arousal
The effects of different strategies on arousal can be quantified and compared
Using the GSR in Meditation
By recording arousal during meditation, the individual can examine how changes to arousal correlate with their subjective experiences
The GSR recording can also be examined by the meditator’s guide who can then offer the practitioner additional feedback