Why one task is not enough: functional MRI for atypical language organization in two children.

Functional MRI is increasingly used to determine the hemispheric dominance for language. This is especially relevant in children who may not be able to comply with the high demands of a Wada test. We here report on two children in which the full extent of language reorganization was only determined when two fMRI tasks were analyzed; in the first case, the results from the second task corroborated the shifted hemispheric dominance seen in the first task. In the second case, the second task showed an opposite hemispheric dominance, suggesting a hemispheric dissociation of language functions. These cases underline the necessity to use more than one fMRI task for the determination of hemispheric dominance, whenever possible. This is particularly relevant in children as unusual patterns of reorganization may be more likely.