Blood flow velocities in three cerebral arteries in the same subjects modulate during thinking.

College students (n = 22) engaged in thinking activities while simultaneous bilateral velocity (V) measures are obtained from their middle, anterior, and posterior cerebral arteries (MCA, ACA, and PCA). The study follows a 3 x 2 x 6 factorial design with repeated measures on artery insonated (MCA, ACA, and PCA), hemisphere (right and left), and six experimental phases, within which an initial 62-second baseline (BL) period is followed by five 31-second thinking tasks (short-term remembering, generating an image, making decisions, and solving language and math problems). VMCA is faster than BL during each thinking task (range, 4.9%-8.5%; p < 0.001), but changes in VACA, VPCA, and all hemispheric differences are not significant. A stronger degree of increase is present for VMCA than (1) both VACA and VPCA during short-duration remembering, making decisions, and working math problems, and (2) VACA, which in turn is stronger than VPCA when generating images and constructing new words. The authors' study shows that transcranial Doppler neuroimaging conveniently provides physiological indices of thinking from three cerebral arteries of the same subjects.