The aim of the study was to examine longitudinal patterns of decision making based on risk and reward using a modified version of the Iowa Gambling Task (IGT) in children who had sustained traumatic brain injury (TBI) and children with orthopedic injury (OI). Participants were 135 children and adolescents with TBI (n=71) or OI (n=64) who were 7-17 years at the time of injury were enrolled and assessed prospectively at baseline and at follow-up intervals of 3, 12, 18, and 24 months after injury. Groups were similar in age, socioeconomic status, and gender. Participants chose from four decks of cards with the aim of maximizing earnings across 100 trials. Two of the decks offered relatively small rewards and relatively small losses, but were advantageous over the course of the experiment. The other two decks offered large rewards, but also introduced occasional large losses, and were considered disadvantageous over the course of the experiment. The variable of interest was the proportion of advantageous decks chosen across trials. Longitudinal analysis of the pattern of change across 2 years revealed a three-way interaction among injury group, age, and the quadratic term of interval-since-injury. In this interaction, the effect of age weakened in the TBI group across time, as compared to the OI group, which showed stronger quadratic patterns across the recovery intervals that differed by age. The OI group generally outperformed the TBI group. In addition, analyses revealed a three-way interaction among group, gender and the cubic term of post-injury interval, such that overall, males improved a great deal with time, but females showed small gains, regardless of injury group.
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