Reversal learning and aging: Exploring simple discrimination learning, learning-set, and functional classes

Cognitive (or behavioral) flexibility is considered an executive function characterized by patterns of behavioral adjustment in response to changes in environmental demands, which tends to decline with aging. The simple discrimination reversal task is a useful way to evaluate this function, as it directly measures processes related to performance change, such as sensitivity to consequences, learning set formation, and concept formation. Few studies on aging have employed this task, and those that have did not examine its component processes or include middle-aged adults. This study aimed to evaluate cognitive flexibility and its component processes through a simple discrimination reversal task, applied to 100 participants divided into four age groups: emerging adults, younger adults, middle-aged adults, and older adults. After learning three simple simultaneous visual discriminations, the function of the positive and negative stimuli was reversed three times, with participants needing to meet a performance criterion each time. Older participants were more likely to fail to meet the performance criterion in some of the reversals, a pattern consistent with reduced sensitivity to consequences and failure in class formation. Moreover, older individuals who succeeded in the task learned the new function assigned to stimuli more slowly during reversals and were less likely to form classes in the second reversal. However, all participants who met the criterion across the three reversals showed evidence of learning-set formation, regardless of age.