| The effects of functional and structural perinatal CNS injury were explored on a task of attention and distractibility in infants at 10 and 16 months. Using a modification of the procedure for measuring focused attention developed by Ruff (H. A. Ruff, M. Capozzoli, & L. M. Saltarelli, 1996), 18 infants in each of four brain injury groups were observed playing with toys while distractors were presented in the periphery. Infants were grouped according to the presence and degree of CNS and/or brainstem injury at birth into: (1) Full-term normal, (2) Neonatal Intensive Care Unit normal, (3) Abnormal Auditory Evoked Brainstem Response only (ABR-Only) and (4) Severe CNS damage. Groups were equivalent in overall looking at the toy and in turns to the distractor at both ages, indicating the same general level of engagement in the experimental task. At 10 months, infants in all groups turned to the distractor less when they were in focused attention and showed a trend towards a longer latency to turn to the distractor during focused attention. At 16 months infants continued to turn less to the distractor while in focused attention, although longer latencies to turn to the distractor were found only for the infants without brain injury. Full term, healthy infants spent a significantly larger proportion of their looking time in focused attention than all other groups at both ages. At 10 months, brain injury groups did not differ in either the number of focused looks or the average duration of a focused epoch. At 16 months, although there were no group differences in the number of times the infants looked at the toys with focused attention, significant group differences emerged in the average duration of a focused epoch, with infants in the ABR-Only and Severe groups having shorter focused epochs. The shorter durations of focused looks for these infants appeared to be characteristic of an early, stimulus-directed attentional system. In contrast, the longer durations of focused attention for the non-injured infants appeared to be more characteristic of a transition to a higher system of attention where inhibitory controls and voluntary direction of attention are increasingly involved. |
