Introduction to a special section of developmental social cognitive neuroscience.

The articles in this special section offer a sample of the state of the art in an exploding new field. Noninvasive neuroimaging techniques, including functional magnetic resonance imaging (fMRI), electroencephalograms (EEG), and functional nearinfrared spectroscopy (fNIRS), are increasingly being used to study development in infants, children, adolescents, and adults. Applying these tools to the study of social cognitive development, in particular, is a very new development. Consequently, in this commentary, we wish to step back and consider the new intersection of neuroscience and social cognitive development. What do these new fields have to offer each other, theoretically and pragmatically? What pitfalls can we expect to encounter along the way? Even in adults, a neuroscience of social cognition is a new invention. Traditional neuroscientific techniques were applied to the brains of nonhuman animals, to study how brains see, hear, feel, move, and remember. Uniquely human cognitive capacities, such as language and social cognition, could not be studied in nonhuman animals. When neuroimaging techniques were first applied to human adults, the key test of these technologies was replication, in humans, of functions known from nonhuman animals. Thus, early neuroimaging focused on the human homologues of known regions from other primates: early visual cortex, the motion perception region (MT), early sensory, and motor cortices. Soon, though, human neuroimaging led to fascinating novel discoveries. The human brain contains many cortical regions, previously unknown or little studied, which have apparently social functions. The fusiform face area (FFA) is involved in perceiving human faces (Kanwisher, McDermott, & Chun, 1997). The extrastriate body area is involved in perceiving human bodies (Downing, Jiang, Shuman, & Kanwisher, 2001). The right posterior superior temporal sulcus (pSTS) is involved in perceiving and analyzing human actions (Pelphrey, Viola, & McCarthy, 2004). The right temporo–parietal junction (RTPJ) is involved in reasoning about people’s thoughts (Saxe & Kanwisher, 2003). The medial precuneus and posterior cingulate and medial prefrontal cortices are involved in other aspects of higher level social cognition (Amodio & Frith, 2006). With the exception of the pSTS (Perrett et al., 1985), these regions were unknown from the studies of nonhuman animals. The discovery of these regions provides an exciting challenge for neuroscientists, and a role for developmental psychology. For neuroscientists, the key questions are: How are high-level social functions implemented in neurons? How do brain regions with these functional roles arise, phylogenetically and ontogenetically? Ideas, experimental paradigms, and data from developmental psychology may help to pose and to address these questions. For example, neuroimaging studies of action representation in the pSTS have been modeled on studies of infants’ action perception (Vander Wyk, Hudac, Carter, Sobel, & Pelphrey, in press); and most early studies of the RTPJ’s role in thinking about thoughts used versions of the false belief paradigm originally developed for studying children (e.g., Fletcher et al., 1995; Gallagher et al., 2000). In the future, we expect that neuroscientists will continue to benefit greatly from the theoretical concepts and paradigms generated within developmental psychology. We express our deepest gratitude to the outstanding reviewers who generously gave of their time in order to help us select the articles for this special section. Kevin Pelphrey and Rebecca Saxe are each supported by awards from the John Merck Scholars Fund and grants from the Simons Foundation. Additionally, a Career Development Award from the National Institute of Mental Health supports Kevin Pelphrey. Correspondence concerning this article should be addressed to Rebecca Saxe, Department of Brain and Cognitive Science, MIT 46-4019, 77 Massachusetts Ave., Cambridge, MA 02139 or to Kevin Pelphrey, Child Study Center, Yale University, 230 South Frontage Rd., New Haven, CT 06520. Electronic mail may be sent to saxe@mit.edu or to kevin.pelphrey@yale.edu. Child Development, July/August 2009, Volume 80, Number 4, Pages 946–951