| It is well known that aging affects fluid cognitive processes while leaving crystallized processes largely intact. When it comes to language abilities, figurative language tends to be more associated with fluid abilities and literal language with more crystallized abilities. Fluid abilities involve short-term storage of information and mental manipulation, which are associated with metaphor interpretation. Eighty participants (40 adults over fifty years old, and 40 young adults) completed the Metaphor Interpretation Test (Iskandar & Baird, 2013). The test includes 17 items chosen from a list of metaphors by Katz et al. (1988). Answers were coded as abstract complete (AC), abstract partial (AP), concrete (CT), or other/unrelated (OT) response. On a multiple choice version of the test, each option represented one of these categories. Participants also completed cognitive tests measuring estimated verbal IQ, short-term memory, working memory, processing speed, mental flexibility, verbal abstraction, and visual abstraction. Overall, younger adults produced a greater number of and chose more AC responses on free and multiple-choice formats of the test, respectively, than older adults. Conversely, older adults produced a greater number of and chose more CT responses on free and multiple-choice formats, respectively, than younger adults. Several measures were associated with aspects of performance on the Metaphor Interpretation Test Verbal short-term memory span most often emerged as a predictor in these analyses. Co-varying on verbal short-term memory span eliminated age-group effects, while co-varying on estimated verbal IQ increased age group differences. Results suggest that aging adversely affects novel metaphor interpretation through age-related limitations in the ability to hold information in mind long enough to search for and link similar cognitive networks. |
