Mental imagery and idiom understanding in adults: Examining dual coding theory.

摘要

This study examined idiom understanding in 120 neurologically healthy adults, ages 20-29 (20s Group), 40-49 (40s Group), 60-69 (60s Group), and 80-89 (80s Group) years old. Each participant was administered a familiarity task, definition explanation task, mental imagery task, and forced-choice comprehension task. Twenty idioms, 10 transparent and 10 opaque, were used with no supporting contexts. Participants were asked to rate the familiarity of each idiom, to provide a definition of each, to generate a mental image of each, and to select the best definition of each from among four options. It was predicted that younger and older adults would perform equally well on the comprehension task but that older adults would perform poorer than younger adults on the explanation task. Additionally, mental imagery of idioms was expected to become more figurative with advancing age, and participants were expected to perform better on highly familiar and transparent idioms than on less familiar and opaque ones.;Participants rated all 20 idioms as highly familiar, with the lowest familiarity rating for participants in the 20s Group. No significant differences were found on the forced-choice comprehension task across the four age groups although the 20s Group scored the lowest among all age groups. The 60s Group performed significantly better than the 20s Group on the definition explanation task, but no significant differences were found between the other age groups. No significant differences were found in generating mental images between transparent and opaque idioms, and mental images tended to be figurative rather than literal for both types of idioms.;The present study adds to our knowledge of idiom understanding across adulthood. Familiarity seemed to play a stronger role than transparency in idiom understanding in adults. Once an idiom was learned and stored as a lexical unit, people used the idiomatic meaning and generated figurative mental imagery immediately without accessing the literal meaning or the literal mental image.