A functional MRI protocol for localizing language comprehension in the human brain.

Overview

We describe a functional magnetic resonance imaging (fMRI) protocol to separate activation of areas in the brain associated with language comprehension from sensory areas activated as a result of the presentation of the language stimulus, by comparing cortical activation patterns during the presentation of similar or the same language stimulus via two different sensory modalities (auditory and visual), and identifying the regions of activation that are common to both modalities. The protocol can be implemented on any MR scanner capable of functional imaging, and has proven valuable for the reliable identification of the lateralization and location of language centres in patients being considered for neurosurgical procedures. As well, the method has potential for the study of cortical processing of auditory speech and written language in healthy subjects and in subjects suffering from language disorders.