The effects of the transposed morpheme on semantic unitization in recognition memory

Abstract

Unitization is described as the process whereby two or more previously separate items or stimulus components are integrated into a single unit, either through perceiving or conceiving of a structure (e.g., semantic meaning) that would connect the disparate units. It is generally believed that semantic association within unitized representations is stable once established. However, the opposing view has suggested that semantic association within unitized representations depends on the features of the to-be-remembered stimulus pairs, which is greatly affected by artificial factors. Thus, semantic association within the unitized representations could be broken up under certain circumstances. Nevertheless, very little experimental evidence exists to support either of the two views. More recently, it has been suggested that familiarity can be used as an indicator for whether the stimuli components are integrated into a unitized representation. It is thought that compound words are “unitized” stimuli with particular morpheme positional information. Therefore, the present study aimed to explore whether semantic unitization within compound words is stable during recognition by employing experimental manipulations involving the transposed morpheme position. Participants were instructed to remember compound words, transposed compound words, and non-compound word pairs. The familiarity-based frontal old/new effect (FN400) was obtained for compound words and transposed compound words during the 400–600 ms period, but not for non-compound word pairs. Additionally, the frontal old/new effects for compound words and transposed compound words did not significantly differ, which could underpin the facilitation of the familiarity process during associative memory of the transposed compound words. Overall, these findings suggest that semantic unitization within compound words was preserved even if the morpheme position was transposed, thus providing support for the view that semantic unitization within compound words is stable.