The measurement of regional cerebral blood flow during the complex cognitive task of meditation: a preliminary SPECT study

This study measured changes in regional cerebral blood flow (rCBF) during t he complex cognitive task of meditation using single photon emission comput ed tomography, Eight experienced Tibetan Buddhist meditators were injected at baseline with 7 mCi HMPAO and scanned 20 min later for 45 min. The subje cts then meditated for 1 h at which time they were injected with 25 mCi HMP AO and scanned 20 min later for 30 min. Values were obtained for regions of interest in major brain structures and normalized to whole brain activity. The percentage change between meditation and baseline was compared. Correl ations between structures were also determined. Significantly increased rCB F (P < 0.05) was observed in the cingulate gyrus, inferior and orbital fron tal cortex, dorsolateral prefrontal cortex (DLPFC), and thalamus. The chang e in rCBF in the left DLPFC correlated negatively (P < 0.05) with that in t he left superior parietal robe. Increased frontal rCBF may reflect focused concentration and thalamic increases overall increased cortical activity du ring meditation, The correlation between the DLPFC and the superior parieta l robe may reflect an altered sense of space experienced during meditation, These results suggest a complex rCBF pattern during the task of meditation . (C) 2001 Elsevier Science Ireland Ltd. All rights reserved,