No abstract

Children and adults were tested on 3 place learning tasks. Children under the age of 7 were inferior to older subjects in solving the tasks by using spatial relational solutions, but subjects of all ages were equally proficient in solving the task by using simple stimulus-reward associations (cued solutions). Accurate performance on the cued versions suggests that neither the general response demands nor the large size of testing environments rendered the tasks differentially inappropriate for young children. Instead, the nature of the cognitive demands were responsible for different levels of performance across the age groups. Because, in animal studies, spatial relational solutions but not cued solutions of these tests require mature and undamaged medial temporal lobe structures, the results suggest that these systems are not fully developed in humans before approximately 7 years of age.

No abstract

Monkeys and children show sex differences on tasks that depend on the orbital prefrontal cortex. To determine whether similar sex differences exist across the life span, adults were tested on an orbital-dependent decision-making task, the Iowa Card Task, as well as on a control task, the California Weather Task. In addition, estradiol, progesterone, and testosterone were assayed. The 6 groups of participants were college-age men, older men, young low-hormone (menstruating) women, young high-hormone (midluteal) women, older postmenopausal women on estrogen replacement therapy (ERT), and older postmenopausal women not on ERT. Results showed a male superiority on the Iowa Card Task. Among college-age men there was a negative correlation between performance and testosterone levels. There were no significant differences among groups of women on the card task. There were no significant sex differences or hormone correlations on the California Weather Task.