Attentional performance of children with traumatic brain injury: a quantitative and qualitative analysis of digit span.

Previous studies have indicated that digit span performance is not particularly sensitive to the effects of traumatic brain injury (Baddeley & Warrington, 1970; Brooks, 1975; Sterne, 1969). However, clinical lore posits poorer backward vs. forward performance compared to normals due to the greater attentional demands of the backward task. This study examined qualitative aspects of Digit Span performance including forward/backward span discrepancies and error patterns in children with traumatic brain injury (n = 20) and normals (n = 19). The hypothesis of greater forward/backward discrepancy with traumatic brain injury was not supported. Children with traumatic brain injury make a significantly greater number of preceiling errors than normals, consistent with other findings of increased performance variability. Preceiling errors are errors that occur in trials prior to the two failed trials, resulting in discontinuation of the task. In addition, cognitive correlates of error types, such as WISC-R factor scores, were significantly different between groups. The results of this study suggest that a more detailed analysis of performance on attentional tasks previously described as resilient to brain injury may shed further light on the nature of acquired attentional deficits.