Performance on the IOWA card task by adolescents and adults

Performance on the Iowa Card Task (ICT) is impaired in several populations that demonstrate poor decision-making and risk-taking including patients with damage to the ventromedial prefrontal cortex. For some individuals, adolescence is a period of poor decision-making and risk-taking. Adolescence is also a period of neuroanatomic and neurochemical remodeling. There is evidence that neuropsychological functions of the prefrontal cortex change during adolescence; however, decision-making, as measured by the ICT, has not been systematically studied in adolescents over the age of 14 years. In the present study, 60 participants (30 female) in each of grades 6-12, and 60 young adults were administered the Iowa Card Task, the Wisconsin Card Sorting Task (WCST), a survey of impulsivity and excitement-seeking, and a quantity-frequency index of substance use. Results showed significant and steady improvement on the Iowa Card Task from the 6th grade to adulthood. Performance on the Iowa Card Task was not correlated with measures of impulsivity, excitement-seeking or reported individual substance use. There was one indication that poly-substance use was negatively correlated with performance on the ICT. Performance on the WCST was not significantly correlated with performance on the Iowa Card Task or any other measure. Across age, males and females had a different response pattern on the ICT. Females tended to choose cards associated with both immediate wins and with long-term outcome. Males tended to choose on the basis of long-term outcome. Results are discussed in terms of adolescent brain development and decision-making differences between males and females.