Deficits in the covert orienting of attention in children with Developmental Coordination Disorder: does severity of DCD count?

Children with Developmental Coordination Disorder (DCD) show deficits in the covert orienting of visuospatial attention, suggesting an underlying issue in attentional disengagement and/or inhibitory control. However, an important theoretical issue that remains unclear is whether the pattern of deficits varies with DCD severity. Fifty-one children with moderate DCD (MDCD), 24 children with severe DCD (SDCD), and 38 typically developing (TD) children participated in the study. Their performance was compared on the covert orienting of visuospatial attention task (COVAT), specifically the voluntary control mode. Results showed that the pattern of performance differed between groups. At a short stimulus-response asynchrony (350 ms), the difference in response times for validly and invalidly cued trials was similar for all three groups. However, at the longer SOA (800 ms), both DCD groups continued to show a relative disadvantage for responses that followed invalid cues. This suggests that a deficit in response inhibition and/or attentional disengagement is manifest in children with both moderate and severe DCD. The implications of these findings for theory and treatment are discussed.