PET imaging during auditory stimulation

Abstract

Positron emission tomography (PET) provides a means of studying regional brain activity in vivo. PET measurements of regional cerebral blood flow (rCBF) were obtained in 3 subjects with normal hearing during the continuous inhalation of CO15O. A nominally unstimulated 3‐min period, during which a moderate level of apparatus noise was present, was followed by the continuous binaural presentation of white noise (3 min). In addition, dichotic stop‐consonant and complex pitch discrimination tests (3 min) were administered to two subjects. White noise produced 10%–15% and 15%–25% increases in rCBF in the temporal lobes and thalamus, respectively. Increases were also observed in nonauditory structures: 10%–25% in medial frontal cortex and 5%–10% in medial occipital cortex. In contrast, maximum changes in rCBF during speech and pitch discrimination were of smaller magnitude and occurred over more restricted cortical regions. These results suggest that continuous white noise produces significant increases in rCBF...