The Ontogenetic Development of Hemispheric Lateralization During Face Processing: A Functional Magnetic Resonance Imaging Pilot Study in 7- to 9-Year-old Children

Twelve children aged 7-9 years, and ten adults were measured with a face localizer task that was specifically adapted for children. Our results showed that it is possible to localize the core system’s brain regions in children even at the single subject level. We further found a (albeit non-significant) trend for increased right-hemispheric lateralization of all three regions in adults compared to children, with the largest effect for the FFA (estimated effect size d=0.78, indicating medium to large effects). Using these results as basis for an informed power analysis, we estimated that an adequately powered (sensitivity 0.8) follow-up study testing developmental changes of FFA lateralization would require the inclusion of 18 children and 26 adults.