Science is finally beginning to prove these claims, with new evidence that regular practice of TM can alter the brains of children with attention-deficit/hyperactivity disorder (ADHD), improving focus and verbal ability (Mind & Brain: J Psychiatry, 2011; vol 1 no 2; online).
In the Washington, DC, study, neuroscientists at the Center for Brain, Consciousness and Cognition and George Washington University monitored children, aged 11-14, with language-based learning disabilities with regular electroencephalography (EEG) tests of brain functioning while they were performing a complex computer-based visual-motor task, requiring keen attention, memory and focus, while also being given a verbal-fluency test, which examined vocabulary, spelling and attention.
The tests and the monitoring were carried out prior to and then after initiation of regular meditation in one group of children, while another group served as controls.
During ordinary waking conscious-ness,the brain uses a predominance of the faster beta waves (around 13-40 Hz) and a smaller percentage of slower theta waves (4-7 Hz), which typify the state of consciousness during deep sleep, but also when focusing on inner mental tasks, such as association or memory-processing (Murphy M, Donovan S. The Physical and Psychological Effects of Meditation: A Review of Contemporary Research With a Comprehensive Bibliography, 1931-1996. Petaluma, CA)
Ordinarily, this lower level of theta activity enables the brain to block out any irrelevant data in order to focus. In a child with ADHD, however, the beta-to-theta ratio is altered, with higher theta and lower beta activity than normal, meaning that the brain blocks out the relevant as well as the irrelevant. This ratio of brainwave activity also lowers the ability to concentrate on a particular task.
In addition, studies of children with ADHD reveal higher-than-normal levels of stress, which also affect the ability to focus. Consequently, the purpose of the Washington study was to determine whether TM, known to help lower levels of stress, might also help to improve the ability to focus and process information.
By the end of the study, those children practising TM for six months showed a 48-per-cent reduction in the ratio of theta-to-beta brainwaves. This compares with a 3-per-cent decrease in this brainwave ratio through drugs such as Ritalin, used to treat attention deficit,and a 25-per-cent increase with neurofeedback.
Furthermore, parental surveys taken at the end of the study reported improvements in the children's overall happiness and quality of sleep, and their ability to focus and work independently.
Permanent brain changes
But how does meditation change the brain?
Richard Davidson, a neuroscientist and psychologist at the University of Wisconsin's Laboratory for Affective Neuroscience, who has regularly studied expert and novice meditators, found that meditation alters brainwave patterns,even among new practitioners. Neophytes who practised meditation for only eight weeks showed increased activation of the 'happy-thoughts' part of the brain(Psychosom Med, 2003; 65: 564-70).
Daniel Goleman, author of Emotional Intelligence (Bloomsbury Press, 1996), carried out research showing that the brain cortices of meditators "get cut off from" the limbic emotional centre. This suggests that meditation enhances mechanisms of attention and perception while tuning out emotional 'noise' (Am J Psychother, 1976; 30: 41-54;Psychology Today, 1976).
Another important effect of concentrated focus is the integration of both left and right hemispheres. Until recently,scientists believed that the two sides of the brain worked more or less independently. The left side was depicted as the 'accountant', responsible forlogical, analytical, linear thinking and speech, while the right side was the'artist', providing spatial orientation, musical and artistic ability, and intuition.
But Peter Fenwick, consultant neuropsychiatrist at the Radcliffe Infirmary in Oxford, and St Thomas'Hospital, Bethlem Royal Hospital and the Institute of Psychiatry at Maudsley Hospital in London, has gathered evidence to show that speech and many other functions are produced in both sides of the brain, and that the brain works best when it can operate as a totality. During meditation, both sides communicate in a particularly harmonious-or coherent-manner (Biol Psychol, 1977; 5: 101-18).
Brainwaves also become synchronized during meditation. At least 25 studies of meditation have shown that, during meditation, EEG activity between the four regions of the brain fall into synch (Murphy, op. cit.). Also, the ADHD study found a 30-per-cent increase in coherent brain waves in children practising meditation (Mind & Brain, op. cit.).
In addition, meditation appears to permanently enhance the brain's reception. In several studies, meditators were exposed to repetitive stimuli, such as light flashes or clicks. Ordinarily, a person grows accustomed to the clicks, and the brain, in a sense, switches off and stops reacting. But the brains of meditators continue to react to the stimuli-an indication of heightened perception (Electroencephalogr Clin Neuro-physiol, 1975; 39: 519-22).
A thicker brain
Sara Lazar, a neuroscientist at Massachusetts General Hospital and an expert in magnetic resonance imaging(MRI), has confirmed that meditation produces actual physical changes in the brain.
Lazar gathered 20 long-term practitioners of Buddhist mindfulness meditation (five of whom were meditation teachers) who had an average of nine years of meditation experience. Fifteen non-meditators served as controls. Participants meditated in turn inside an MRI scanner, while Lazar took detailed images of their neural structures.
Lazar discovered that those portions of the brain associated with attention, awareness of sensation, sensory stimuli and sensory processing were thicker in the meditators than in the controls. The effects of meditation were 'dose dependent': increases in cortical thickness were proportional to the overall amount of time the participant had been a meditator.
Lazar's research offered some of the first evidence that meditation causes permanent alterations in brain structure.Indeed, the cortical thickness of the regions was even more pronounced in the older participants. Ordinarily, cortical thickness deteriorates as a result of ageing. Regular meditation appears to reduce or reverse the process.
Besides increasing cognitive processing, meditation also appears to integrate emotional and cognitive processes.
In a functional MRI study, Lazar found evidence that meditation appears to affect not only the brain's reasonable,analytical 'upstairs', but also the unconscious and intuitive 'downstairs'. She discovered greater activation in the part of the brain responsible for what is usually called 'gut instinct'. Her work offers physical evidence that meditation not only increases our ability to receive intuitive information, but also our conscious awareness of it (Neuroreport, 2000; 11: 1581-5).
Factfile: Which form of meditation is best?
The short answer is, it depends on what kind of brain power you'd like to enhance.
All forms of meditation make the brain permanently more coherent-as does prayer. A study at the University of Pavia in Italy and the John Radcliffe Hospital in Oxford showed that reciting the rosary had the same effect on the body as repeating a mantra, the technique used in TM. Both were able to create a "striking, powerful, and synchronous increase" in cardiovascular rhythms when recited six times a minute (J Parapsychol, 1998;62: 102-4; Psychol Rep, 1978; 43: 135-43).
Richard Davidson's work has bolstered other pieces of preliminary research suggesting that different forms of meditation produce strikingly different brainwaves. For instance, yogis strive for anuraga, or a sense of constant fresh perception, whereas Zen Buddhists aim to eliminate their response to the outer world. Studies comparing the two find that the former produces heightened perceptual awareness-magnified outer focus-while the latter produces heightened inner absorption-magnified inner awareness (Murphy M, Donovan S. The Physical and Psychological Effects of Meditation: A Review of Contemporary Research With a Comprehensive Bibliography, 1931-1996. Petaluma, CA:The Institute of Noetic Sciences, 1997).
Davidson also found evidence that Buddhist monks practising compassionate meditation have greater activation of the left anterior portion of the brain-the portion most associated with joy and happiness. In addition, his research shows increases in the 'approach' portion of the brain-the part that wants to help-in his monks, who are attempting to help humanity by meditating on compassion. Indeed, they had increased the 'can I help you' portion of their brains.
Lazar's meditators, however, were working on mindfulness, a state of peak attention, and the part of the brain responsible for attention had grown larger. The brain's powers of observation had also increased, allowing more information in, even the sort that is received intuitively.