Magnetoencephalography and functional MRI: A quantitative study of speech perception

T. P.L. Roberts, D. Poeppel, H. A. Rowley

Research output: Contribution to journalConference articlepeer-review


Magnetoencephalography (MEG), sensitive to evoked neuronal activity, and functional magnetic resonance imaging (fMRI), sensitive to hemodynamic consequences of cortical activation, were compared in normal subjects, presented with simple speech elements (vowels). The subjects were instructed either to listen passively or to perform phonetic or pitch discrimination tasks. Sources of activation detected using the two technologies were found to co-localize in the superior temporal gyrus. Furthermore quantification of the evoked responses, using both techniques, revealed a task-induced bilateral increase in activation, with the greatest increases observed in the left hemisphere, during performance of the phonetic discrimination task. It is concluded that not only do fMRI and MEG indicate similar underlying cortical activation areas, but that they offer quantitative indices of hemispheric lateralization induced by performance of a linguistic task. Their co-variance with respect to hemisphere and task performance suggests that despite their different neurophysiological sensitivities (hemodynamic changes vs. neuronal electrical activity), both techniques offer quantitative approaches to the study of speech perception, and by extension, to the processing of language.

Original languageEnglish (US)
Pages (from-to)2120-2123
Number of pages4
JournalAnnual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings
StatePublished - 1998
EventProceedings of the 1998 20th Annual International Conference of the IEEE Engineering in Medicine and Biology Society. Part 4 (of 6) - Hong Kong, China
Duration: Oct 29 1998Nov 1 1998

ASJC Scopus subject areas

  • Signal Processing
  • Biomedical Engineering
  • Computer Vision and Pattern Recognition
  • Health Informatics


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