FUNCTIONAL MAGNETIC-RESONANCE-IMAGING OF THE CENTRAL AUDITORY PATHWAYFOLLOWING SPEECH AND PURE-TONE STIMULI

Functional magnetic resonance imaging (FMRI) is a new noninvasive tech nique for imaging cerebral function. Studies of the human central audi tory pathway examined responses in eight normal hearing volunteers fol lowing auditory stimuli, including narrative speech and pure-tone audi ometry. The activation demonstrated by FMRI is modeled on an increase in regional blood flow with increased neuronal. activity. The FMRI sig nals represent deoxyhemoglobin concentration changes in capillaries wi thin the region of the brain that is activated Brain activation was im aged in the superior temporal gyrus during text reading and pure tones . Activation in both text and pure-tone presentation did not vary with the intensity of the auditory stimulus and elicited a dominant respon se in the left temporal lobe. These observations demonstrate the capab ility of FMRI to correlate anatomic and functional relationships in th e human central auditory pathway.