Pagnoni, G., et al. (2008) “Thinking about not-thinking”: Neural correlates of conceptual processing during Zen meditation. PLoS ONE 3(9). Full text.
From the abstract: “Zen practitioners displayed a reduced duration of the neural response linked to conceptual processing in regions of the default network, suggesting that meditative training may foster the ability to control the automatic cascade of semantic associations triggered by a stimulus and, by extension, to voluntarily regulate the flow of spontaneous mentation.”