Aim: The aim of this study was to investigate the changes in the cerebral blood flow that took place in normal subjects during an auditory attention paradigm which included automatic and controlled processing components.
Method: Participants consisted in 10 normal subjects who were submitted to medical, neuropsychological and neuroimaging evaluation. PET was used to carry out an exploration of each subject in the four experimental conditions: basal, listening to clicks (A), counting while listening to clicks (C+A) and counting without listening to clicks (C).
Results: During the condition involving counting while listening to clicks (automatic processing) the subjects displayed a significant increase in the activation of the bilateral precentral convolutions, left dorsolateral prefrontal cortex (DLPFC), left inferior and superior frontal convolutions, left supplementary motor area and the left superior and inferior temporal convolution. During the condition involving counting without listening to clicks (controlled processing), the subjects activated the right precentral convolution, bilateral DLPFC, the right supplementary motor area, anterior cingulate and right inferior parietal convolution.
Discussion: The results obtained support the suggestion that regions such as the DLPFC and the inferior parietal convolution play a part in attentional tasks in which the subject is required to make an effort to carry out the controlled processing of information.