An fMRI task battery for assessing hemispheric language dominance in children

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Neuroimaging

Background:

• Assessing hemispheric language dominance is crucial in neuroimaging, especially for children, to avoid invasive procedures like the Wada test.
• Current functional neuroimaging (fMRI) methods for language dominance assessment need improvement for pediatric use and performance monitoring.

Purpose of the Study:

• To develop and validate novel fMRI paradigms for assessing language dominance in children.
• To compare the efficacy of new tasks (letter, animal) against established tasks (synonyms, verb generation) in pediatric populations.

Main Methods:

• Twenty-three healthy children (ages 6.1-15.3 years) underwent fMRI scans using four language tasks: letter, animal, synonyms, and verb generation.
• Data analysis employed statistical non-parametrical mapping (SnPM2) on SPM2 to identify brain activation and assess lateralization.

Main Results:

• Reference tasks (synonyms, verb generation) activated left-frontal regions, but also non-language areas.
• The letter task demonstrated highly localized activation in Broca's region, showing strong and consistent lateralization.
• The animal task was unsuitable for assessing language dominance in this pediatric cohort.

Conclusions:

• The letter task selectively activates language areas in the dominant hemisphere, proving effective for children, including the youngest amenable to fMRI.
• This task allows for performance monitoring and offers a valuable alternative to invasive methods for assessing language organization.