Expert individuation of objects increases activation in the fusiform face area of children.

The role of experience in the development of brain mechanisms for face recognition is intensely debated. Experience with subordinate- and individual-level classification of faces is thought, by some, to be foundational in the development of the specialization of face recognition. Studying children with extremely intense interests (EII) provides an opportunity to examine experience-related changes in non-face object recognition in a population where face expertise is not fully developed. Here, two groups of school-aged children -one group with an EII with Pokémon cards and another group of age-matched controls - underwent fMRI while viewing faces, Pokémon characters, Pokémon objects, and Digimon characters. Pokémon objects were non-character Pokémon cards that experts do not typically individuate during game play and trading. Neither experts nor controls had previous experience with Digimon characters. As expected, experts and controls showed equivalent activation in the fusiform face area (FFA) with face stimuli. As predicted by the expertise hypothesis, experts showed greater activation than controls with Pokémon characters, and showed greater activation with Pokémon characters than Pokémon objects. Experts and controls showed equivalent activation with Digimon characters. However, heightened activation with Digimon characters in both groups suggested that there are other strong influences on the activation of the FFA beyond stimulus characteristics, experience, and classification level. By demonstrating the important role of expertise, the findings are inconsistent with a purely face-specific account of FFA function. To our knowledge, this is the first demonstration of the effects of expertise and categorization level on activation in the FFA in a group of typically developing children.