Cerebral blood flow velocity changes during meaningful and meaningless gestures--a functional transcranial Doppler study

The aim of the study was to use functional transcranial Doppler to investigate the possibility of revealing different activation patterns during healthy subjects' performance of meaningful and meaningless actions. Mean flow velocity (MFV) changes were recorded in middle cerebral arteries (MCAs) of 26 normal subjects during a rest phase and during performance of meaningful and meaningless actions. The meaningful task consisted of pouring sugar into a cup with a teaspoon. The meaningless action was an arm movement similar to that necessary for pouring sugar in a cup but without any tool and thus without a goal. Performing actions with or without meaning was associated with different patterns of MFV changes, as documented by the triple interaction condition x performing arm x side of recording [F(1, 25)=10.977; P=0.003]. During the meaningful action, MFV in MCAs increased significantly more than during the meaningless action. During the meaningless action, the MFV increase was significantly higher in the contralateral than in the ipsilateral MCA to the arm performing the task and the meaningful action determined a bilateral MFV increase only when the task was performed with the left arm. When the same task was performed with the right arm, the MFV increase was significantly higher in the contralateral than in the ipsilateral MCA. These findings suggest that the content of an action can influence MFV changes and further confirm the usefulness of transcranial Doppler in neuropsychological investigation.