Pesquisadores da Universidade de Yale, nos Estados Unidos, comprovaram, com a ajuda de imagens, que a meditação frequente, além de propiciar a desidentificação com o “eu” e desconectar as áreas do cérebro relacionadas com o “sonhar acordado” e divagações (que tendem a se focar em temas negativos), também provoca uma diminuição na actividade de áreas cerebrais que têm ligação com transtornos psiquiátricos como o autismo, esquizofrenia, défice de atenção, ansiedade, hiperactividade e inclusive o acumular de placas de beta-amilóide na doença de Alzheimer.
A análise mostrou também que, em geral, quando há meditação, as regiões do cérebro associadas com o controle cognitivo activam-se.
Durante o estudo do professor de psiquiatria Judson Brewer e da sua equipa, os voluntários foram convidados a participar de três tipos diferentes de meditação, e ao longo do processo os cientistas puderam examinar a actividade cerebral com imagens de uma ressonância magnética.
Study finds that regular practice of meditation results in structural changes in the brain
The structural changes were found in areas of the brain that are important for sensory, cognitive and emotional processing, the researchers report in the November issue of NeuroReport.
Although the study included only 20 participants, all with extensive training in Buddhist Insight meditation, the results are significant, says Jeremy Gray, assistant professor of psychology at Yale and co-author of the study led by Sara Lazar, assistant in psychology at Massachusetts General Hospital.
"What is most fascinating to me is the suggestion that meditation practice can change anyone's grey matter," Gray says. "The study participants were people with jobs and families. They just meditated on average 40 minutes each day; you don't have to be a monk."
Magnetic resonance imaging showed that regular practice of meditation is associated with increased thickness in a subset of cortical regions related to sensory, auditory, visual and internal perception, such as heart rate or breathing. The researchers also found that regular meditation practice may slow age-related thinning of the frontal cortex.
"Most of the regions identified in this study were found in the right hemisphere," the researchers report. "The right hemisphere is essential for sustaining attention, which is a central practice of Insight meditation."
The researchers say other forms of yoga and meditation likely have a similar impact on cortical structure, although each tradition would be expected to have a slightly different pattern of cortical thickening based on the specific mental exercises involved.
Co-authors include Catherine Kerr, Rachel Wasserman, Jeffery Dusek, Herbert Benson and Metta McGarvey of Harvard; Douglas Greve, Brian Quinn, Bruce Fischl, Michael Treadway and Scott Rauch of Massachusetts General Hospital; and Christopher Moore of the Massachusetts Institute of Technology.