Inhibition of return in children with perinatal brain injury JEFFREY SCHATZ, 1 SUZANNE CRAFT, 2,3 DESIREE WHITE, 1 T.S. PARK, 4 and GARY S. FIGIEL 5 1 Department of Psychology, Washington University, St. Louis, Missouri 2 Geriatric Research, Education and Clinical Center, VeteransAffairs Puget Sound Health Care System, Seattle, Washington 3 Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, Washington 4 Department of Neurology and Neurological Surgery and St. Louis Children’s Hospital, Washington University School of Medicine, St. Louis, Missouri 5 Department of Psychiatry, Emory University, Atlanta, Georgia (Received August 5, 1999; Revised February 7, 2000, Accepted February 8, 2000) Abstract Inhibition of return is a bias in attention that reduces the likelihood of returning attention to previously viewed locations. This attention bias develops during the first 6 months of life and is putatively mediated by midbrain structures. The present study evaluated the effects of perinatal lesions on the development of inhibition of return. Thirty-three children with perinatal injury resulting in spastic diplegic cerebral palsy were grouped based on magnetic resonance exams. Children with anterior ( n 5 5), posterior ( n 5 12), diffuse ( n 5 8), or no apparent ( n 5 8) lesions were compared with a group of age-matched children without neurologic injury ( n 5 39) on an orienting task designed to elicit inhibition of return. Short-delay trials demonstrated grossly intact facilitation of attention for all groups. Long-delay trials that produced inhibition of return in the control and posterior injury groups indicated a disruption of inhibition of return in the groups with anterior and diffuse lesions. The findings are consistent with previous reports that anterior regions are important for the developing attention system, and that bilateral injury can result in unilateral disruption of visual attention. ( JINS, 2001, 7, 275–284.) Keywords: Attention, Visual processing, Cerebral palsy, Cognitive INTRODUCTION Inhibition of return is a normal attention mechanism that increases the likelihood of attending to novel stimuli. This attentional bias is often demonstrated by drawing attention to a particular location and then away from this location. For a period of approximately 200 to 1200 ms following the movement of attention away from the original location, one is slower to return attention to the original location than to a novel location. In adults, this attentional bias is presumed to be related to the programming of eye movements, and has been shown to be disrupted by conditions affecting the superior colliculus (Posner et al., 1985; Rafal et al., 1989). Inhibition of return first appears in development between the third and sixth month of life (Clohessy et al., 1991; John- son et al., 1991). The development of inhibition of return also coincides with the onset of the ability to program eye movements to specific locations. This correlation in devel- opment also supports the link between saccadic eye move- ments and inhibition of return. Posner et al. (1984, 1988) have described inhibition of return as part of the posterior attentional network involving the parietal lobe, pulvinar, and superior colliculus. They also note, however, that the time frame for the appearance of inhibition of return closely fol- lows the maturation of the pathways between the frontal eye fields and superior colliculus. Thus, it is possible that ante- rior corticocollicular connections play a primary role in the development of inhibition of return. In a series of studies of visual orienting, structural and functional lesions affecting anterior regions in the develop- ing brain have been shown to disrupt the rapid facilitation and disengagement of attention (Craft et al., 1992, 1994a, 1994b; Heffelfinger et al., 1997). For example, children with anterior perinatal lesions have shown a lateralized impair- ment in the rapid engagement of attention that is similar to the reported findings of adults with midbrain lesions (Craft et al., 1994b). The cause for this pattern of performance has been proposed by Craft and colleagues to be the disruption of connections from the frontal eye fields and surrounding regions with subcortical collicular regions. The loss of nor- Reprint requests to: Jeffrey Schatz, Department of Psychology, Uni- versity of South Carolina, Columbia, South Carolina 29208. E-mail: schatz@sc.edu Journal of the International Neuropsychological Society (2001), 7, 275–284. Copyright © 2001 INS. Published by Cambridge University Press. Printed in the USA. 275