Developmental changes within the extended face processing network: A cross‐sectional functional magnetic resonance imaging study

Abstract

In the field of face processing, the so‐called “core network” has been intensively researched. Its neural activity can be reliably detected in children and adults using functional magnetic resonance imaging (fMRI). However, the core network's counterpart, the so‐called “extended network,” has been less researched. In the present study, we compared children's and adults’ brain activity in the extended system, in particular in the amygdala, the insula, and the inferior frontal gyrus (IFG). Using fMRI, we compared the brain activation pattern between children aged 7–9 years and adults during an emotional face processing task. On the one hand, children showed increased activity in the extended face processing system in relation to adults, particularly in the left amygdala, the right insula, and the left IFG. On the other hand, lateralization indices revealed a “leftward bias” in children's IFG compared to adults. These results suggest that brain activity associated with face processing is characterized by a developmental decrease in activity. They further show that the development is associated with a rightward migration of face‐related IFG activation, possibly due to the competition for neural space between several developing brain functions (“developmental competition hypothesis”).

Sex differences in development of functional connections in the face processing network

“…Four ROIs representing extended face regions were examined—left and right AMG (26, −10, −16 and 22, −10, −16 respectively), rIFG‐oper (44, 11, 30), and rIFG‐orb (46, 32, −14)—as they are established regions of the extended face network 1,5 and show developmental change 3,4,35–37 . Focusing on a smaller set of ROIs will also help mitigate issues with multiple comparisons.…”

Let’s face it: The lateralization of the face perception network as measured with fMRI is not clearly right dominant

“…High interindividual variability of the hemispheric lateralization of the face peerception network is also in accordance with our own anecdotal experience. Our research group has conducted numerous fMRI studies on face processing over the last years, often in the context of hemispheric lateralization (e.g., Frässle et al, 2016aFrässle et al, , 2016bFrässle et al, , 2016cHildesheim et al, 2020;Sahraei et al, 2021;Thome et al, 2021;Zimmermann et al, 2019). In these studies, it was often necessary to assess the fMRI activation patterns not only at the group level, but also at the individual level, e.g., in order to determine the spatial location of core system regions for further analyses.…”