by Tim Brunson, PhD
Meditation is an often misunderstood practice with several variations that are taught by many different religions. It often is described in terms of calm-abiding (i.e. a quieting of the mind) or analytical (i.e. focused on a particular concept such as compassion). The unifying concept is a meditator's ability to harness their mental processes.
The direct mental benefits of a successful meditation session include a quieting of the anterior cingulate cortex (ACC) – which plays a key role in transitioning between thoughts – and the activation of the parasympathetic division of the autonomic nervous system. However, while this may have a relaxation benefit – with all the implications for improving the digestive process and boosting the immune system – researchers are increasingly becoming aware of the potential for meditation to help with higher brain functions. Indeed, beyond the benefits derived from meditation-induced relaxation, it is the stimulative affect of analytical meditation that may have the biggest benefit.
This is highlighted in a recent study conducted at the UCLA School of Medicine (Luders et al., 2009). Their research showed that there is evidence of meditation-induced improvements in psychological and physiological well-being. Benefits were noticed in higher-order cognitive functions as meditation altered brain activity. The study used high-resolution MRI data from 44 subjects. One of the goals was to specifically observe changes in substrate activity. What they found was an increase in the grey-matter density of the right orbitofrontal cortex (R-OFC). Also, improvements were noted in the right thalamus and the right hippocampus. These benefits come mainly from the ability to use imagination and visualization to activate the R-OFC.
Another recent study gives additional evidence as to the ability of meditators to affect neurological change. Research conducted at Aarhus University in Denmark (Vertergaard-Poulsen, et al., 2009) showed that "extensive practice involving sustained attention can lead to changes in brain structure." Using MRIs, their research discovered that the long-term practice of meditation correlated with higher gray matter density in lower brainstem regions, as compared to age-matched non-meditators. Specifically, the structural differences in brainstem regions were those involved in cardiorespiratory control. The research team concluded that there could be a relationship between "cardiorespiratory parasympathetic effects and traits, as well as cognitive, emotional, and immunoreactive impact reported in several studies of different meditation practices." (Vertergaard-Poulsen, et al., 2009) [Cardiorespiratory regulation involves the reticular activating system (RAS or ARAS) located within the brain stem. The RAS is important to conscious awareness.]
Newberg and D'Aquila (2001) were among the first to recognize that meditation has a left prefrontal lobe inhibitory role and that activity in the right temporal lobe increases. Benefits of the calming affect on the ACC include having more energy available for other brain functions. Once the mind is trained (or re-patterned) by long-term meditation practices, enhanced mental abilities often emerge. Research by Newberg and others is congruent with statements from Tibetan Buddhist authorities that long-term meditation can produce nearly extra-sensory abilities – which the Tibetans call by the Sanskrit word siddhis. The higher level training of the more experienced Tibetan Buddhist monks has additional secular benefits, such as enhancing their memories. This should not be surprising, as the UCLA study showed the increase in hippocampus size. (Memory difficulties of middle aged and older individuals – to include the onset of Alzheimer's Syndrome – are related to shrinkage of the hippocampi.)
These studies are extremely significant due to the implications concerning the benefits of meditation. Over the past few years several research projects (Davidson, 2007; Negi, 2007; Nemeroff, 2007) have highlighted the impact of attention and imagination on behavior and stress. Many of them specifically address neuro-physiological changes such as oxytocin in cerebral fluid (Nemeroff, 2007). [Oxytocin – which is produced in the hypothalamus and is a factor in emotional bonding and nurturing – is believed to be related to the amount of stress a person can endure before the hypothalamus-pituitary-adrenal (HPA) reaction is triggered.] The improvements in neural performance did not just involve energetic balance. What they found is that the repeated act of meditating grew brain structures, showing that it improves both neural functioning and enhances the neural density. The fact that meditation affected the right hippocampi, which was mentioned in the first study, has implications for improving learning and preventing Alzheimer's Syndrome. The second study highlighted the relationship between attention and imagination and physiology (i.e. cardiorespiratory parasympathetic effects and traits), as well as psychological factors. The body of literature concerning the neurological implications of meditation is growing. However, while extremely significant, much of the information remains prematurely inconclusive.
The International Hypnosis Research Institute is a member supported project involving integrative health care specialists from around the world. We provide information and educational resources to clinicians. Dr. Brunson is the author of over 150 self-help and clinical CD's and MP3's.
References:
Davidson, R. (1992). Emotion and Effective Style: Hemispheric Substrates. Psychological Science 3, 1992a: 39 – 43.
Luders E., Toga A. W., Lepore, N., & Gaser, C. (2009, April 15). The underlying anatomical correlates of long-term meditation: larger hippocampal and frontal volumes of gray matter. Neuroimage. 45(3), 672-8.
Negi, L. T. (2007 October 20). Compassion Meditation: a Cognitive Strategy for Enhancing Social Empathy. Mind & Life XV. Atlanta, Georgia.
Nemeroff, C. B. (2007 October 20). Early Life Factors in Depression. Mind & Life XV. Atlanta, Georgia.
Newberg, A. & D'Aquili, E. (2001). Why God Won't Go Away: Brain Science & The Biology of Belief. New York: Balantine.
Vestergaard-Poulsen P, van Beek M, Skewes J, et al. (2009, Jan 28). Long-term meditation is associated with increased gray matter density in the brain stem. Neuroreport. 20(2), 170 – 4.
Posted: 08/21/2009
