Developmental Science 10:4 (2007), pp F15– F30 DOI: 10.1111/j.1467-7687.2007.00595.x © 2007 The Authors. Journal compilation © 2007 Blackwell Publishing Ltd, 9600 Garsington Road, Oxford OX4 2DQ, UK and 350 Main Street, Malden, MA 02148, USA. Blackwell Publishing Ltd FAST-TRACK REPORT Visual category-selectivity for faces, places and objects emerges along different developmental trajectories K. Suzanne Scherf, 1 Marlene Behrmann, 2 Kate Humphreys 2 and Beatriz Luna 3 1. Department of Psychiatry, University of Pittsburgh, USA 2. Department of Psychology, Carnegie Mellon University, USA 3. Departments of Psychology and Psychiatry, University of Pittsburgh, USA Abstract The organization of category-selective regions in ventral visual cortex is well characterized in human adults. We investigated a crucial, previously unaddressed, question about how this organization emerges developmentally. We contrasted the developmental trajectories for face-, object-, and place-selective activation in the ventral visual cortex in children, adolescents, and adults. Although children demonstrated adult-like organization in object- and place-related cortex, as a group they failed to show consistent face-selective activation in classical face regions. The lack of a consistent neural signature for faces was attributable to (1) reduced face-selectivity and extent of activation within the regions that will become the FFA, OFA, and STS in adults, and (2) smaller volumes and considerable variability in the locus of face-selective activation in individual children. In contrast, adolescents showed an adult-like pattern of face-selective activation, although it was more right-lateralized. These findings reveal critical age-related differences in the emergence of category-specific functional organization in the visual cortex and support a model of brain develop- ment in which specialization emerges from interactions between experience-dependent learning and the maturing brain. Introduction The functional topography of the ventral visual cortex in adults reflects an organized category-selective map with particular stimulus classes eliciting robust and distinct patterns of cortical activation (Downing, Chan, Peelen, Dodds & Kanwisher, 2006; Grill-Spector & Malach, 2004). Converging neuropsychological and neuroimag- ing studies indicate that faces consistently engage a lateral portion of the posterior fusiform gyrus (‘fusiform face area’ [FFA]; Kanwisher, McDermott & Chun, 1997), a lateral region in the inferior occipital cortex (‘occipital face area’ [OFA]; Gauthier, Tarr, Moylan, Skudlarski, Gore & Anderson, 2000), and the superior temporal sulcus (STS; Hoffman & Haxby, 2000). Com- mon objects activate more medial portions of the poste- rior fusiform gyrus and a region of the lateral occipital cortex separable from the face-related region (LO; Grill- Spector, Kushnir, Edelman, Avidan, Itzchak & Malach, 1999), whereas buildings and landscapes activate the collateral sulcus (CoS; Aguirre, Zarahn & D’Esposito, 1998) and the parahippocampal gyrus (‘parahippocam- pal place area’ [PPA]; Epstein & Kanwisher, 1998). Almost nothing is known about how this functional topography in the ventral temporal lobe emerges develop- mentally. None of the existing developmental neuroimag- ing studies has mapped object- or place-specific activation in children under the age of 9. The few existing studies have focused on the development of face-related activation specifically in the fusiform gyrus. Although a PET study with infants suggested that face-related activation may be present in 2-month-old infants (Tzourio-Mazoyer, De Schonen, Crivello, Reutter, Aujard & Mazoyer, 2002), fMRI studies, which have better spatial resolution, indicate that the FFA is not adult-like even in early adolescence (Aylward, Park, Field, Parsons, Richards, Cramer & Meltzoff, 2005; Gathers, Bhatt, Corbly, Farley & Joseph, 2004; Passarotti, Paul, Bussier, Buxton, Wong & Stiles, 2003). In addition to the discrepant findings about the age at which face- related activation is present in the fusiform gyrus, there is no consensus about the mechanism of developmental change underlying this pattern of activation. Some evidence Address for correspondence: K. Suzanne Scherf, Western Psychiatric Institute & Clinic, University of Pittsburgh, 108 Loeffler Building, 3811 O’Hara Street, Pittsburgh, PA 15213, USA; e-mail: scherf@pitt.edu