Resultados en el estudio del córtex auditivo mediante resonancia magnética funcional (I): características generales y resultados individuales

Abstract

ObjectiveTo demonstrate and investigate the activation patterns of the primary auditory cortex (Heschl's gyrus) using functional magnetic resonance imaging (fMRI). Material and methodsPure tone stimuli at 750 Hz and 2000 Hz were delivered to the right and left ear of 32 normal-hearing volunteers (18-49 years old) in 20-second on-off cycles. The fMRI data were obtained using a 1.5 Tesla scanner and processed with SPM2. ResultsFor both tone frequencies, bilateral hemispheric activation was identified in the transverse temporal gyrus (Heschl's gyrus) in 29 subjects (90.62 %) in response to pure tone stimuli with a probability level of p<0.001. For monaural stimulation, bilateral hemispheric activation was observed with generally greater extent of activation in the Heschl's gyrus (HG) contralateral to the stimulated ear. ConclusionsThese results demonstrate that fMRI is a useful imaging technique to investigate the auditory cortex. The contralateral auditory cortex is more responsive than the ipsilateral cortex to tones presented monaurally.