Developmental Science 7:5 (2004), pp 534–542 © Blackwell Publishing Ltd. 2004, 9600 Garsington Road, Oxford OX4 2DQ, UK and 350 Main Street, Malden, MA 02148, USA. Blackwell Publishing, Ltd. REPORT Role of caudate in attention switching Early development of subcortical regions involved in non-cued attention switching B.J. Casey, 1 Matthew C. Davidson, 1 Yuko Hara, 1 Kathleen M. Thomas, 2 Antigona Martinez, 3 Adriana Galvan, 1 Jeffrey M. Halperin, 4 Claudia E. Rodríguez-Aranda 5 and Nim Tottenham 1,2 1. Sackler Institute, Weill Medical College of Cornell University, USA 2. Institute of Child Development, University of Minnesota, USA 3. Nathan Kline Institute, USA 4. Department of Psychology, Queens College of the City University of New York, USA 5. Department of Psychology, University of Tromsø, Norway Abstract This study examined the cognitive and neural development of attention switching using a simple forced-choice attention task and functional magnetic resonance imaging. Fourteen children and adults made discriminations among stimuli based on either shape or color. Performance on these trials was compared to performance during blocked trials requiring all color or all shape discriminations. Magnetic resonance echo planar images were acquired during performance of the task. Both children and adults showed robust bilateral activity of the caudate nucleus when switching attention between color and shape discriminations that correlated negatively with mean response latency on these trials. However, neither switching costs nor caudate activity correlated with age, suggesting early development of the underlying neural circuitry involved in switching between salient stimulus sets. Overall, children and adults differed in performance and patterns of brain activity on the task, with adults responding more accurately and faster than children, and recruiting more prefrontal and parietal regions. These results suggest an important role of subcortical regions (i.e. caudate nucleus) in non-cued attention switching, with increasing recruitment of cortical regions with age. Introduction The ability to switch or redirect our attention between competing inputs is a key component of cognitive func- tioning (Shallice, 1981, 1988; Kahneman, Treisman & Burkell, 1983; Baddeley, 1986; Cohen & Servan-Schreiber, 1992; Desimone & Duncan, 1995; Miller & Cohen, 2001) that becomes more efficient with age (Tipper, Bourque, Anderson & Brehaut, 1989; Diamond, 1990; Brainerd & Reyna, 1993; Dempster, 1993; Harnishfeger & Bjorkland, 1993; Zelazo, Burack, Benedetto & Frye, 1996; Casey, Durston & Fossella, 2001; Cepeda, Kramer & Gonzalez de Sather, 2001; Munakata & Yerys, 2001). Neural correlates of attention-switching behavior have been identified largely through neuro-imaging studies. In these studies, attention switching is accompanied by activity in the prefrontal cortex and the posterior parietal cortex, both connected to the dorsal striatum in corticostriatal loops (Alexander, DeLong & Strick, 1986; Alexander, Crutcher & DeLong, 1990; Dove et al., 2000; Kimberg, Aguirre & D’Esposito, 2000; MacDonald, Cohen, Stenger & Carter, 2000; Sohn et al., 2000; Cools, Barker, Sahakian & Robbins, 2001a, 2001b). The importance of the striatum, particularly the caudate nucleus, in attention switching has been shown in a number of imaging, clinical and animal studies. Adult and developmental neuro-imaging studies show recruit- ment of this region in inhibiting competing stimulus or behavioral sets during saccade (Luna et al., 2001), stimulus– response incompatibility (Casey et al., 2002a) and attention- switching tasks (Sohn et al., 2000). Individuals with Parkinson’s disease, which primarily affects dopamine levels in the striatum, have been shown to be impaired in attention-switching tasks when stimuli prime the competing task set (Cools et al., 2001b). Children with Attention Deficit Hyperactivity Disorder, a disorder Address for correspondence: B.J. Casey, Sackler Institute for Developmental Psychobiology, Weill Medical College of Cornell University, 1300 York Avenue, Box 140, Suite F-1332, New York, NY 10021; e-mail: bjc2002@med.cornell.edu