Attention processing abnormalities in children with traumatic brain injury and attention-deficit/hyperactivity disorder: differential impairment of component processes.

Individuals with acquired and neurodevelopmental brain disorders often exhibit deficits in attention. Recent models of attention have conceptualized it as a multicomponent system. One influential model proposed by Mirsky et al. (1991) consists of factors that include focus, sustain, shift, and encode components. This model has been used to examine the structure of attention in a variety of clinical populations although few studies have contrasted performance of various clinical groups in order to determine whether these components are differentially affected. To address this issue, the current study investigated the differential sensitivity of these attention components in 90 children: 30 who had sustained traumatic brain injury (TBI), 30 who were diagnosed with attention-deficit/hyperactivity disorder (ADHD), and 30 normal controls. Results demonstrated that the TBI group had significantly lower focus factor scores, the ADHD group had significantly lower sustain scores, and that both clinical groups had lower encode factor scores than controls. Stepwise discriminant function analysis (DFA) retained the focus and encode factors in predicting clinical groups from controls with 75.6% accuracy. A second DFA retained the focus factor in differentiating the two clinical groups with 70.0% accuracy. These findings provide evidence of differential attention deficits resulting from TBI and ADHD.