Working memory and aided AAC display design options for students with intellectual disabilities

Working memory (WM) plays an important role when using external communication aids. Various stimuli can be utilized to reduce one's cognitive load when selecting symbols on a grid display. The current empirical findings concerning the benefits of such aids for children and adolescents with intellectual disabilities are inconclusive. This study seeks to fill this gap in scholarly research by investigating the relationship between WM and different stimuli to identify effective grid designs.The sample consists of 80 students who completed a series of WM tasks before being assigned a specific grid design (background colors, frames, wide space). The task was to select a target symbol presented auditorily within a 4 x 6 grid display. Response times were measured. A linear mixed model with subsequent post-hoc tests was employed to analyze the predicted response time based on the WM performance and the specific display design. Possible learning effects were also considered.Enhanced WM performance did not invariably lead to faster symbol selection. However, a comparison of the two performance groups revealed that the stronger performing cohort performed better under conditions of background color design. The phonological loop and the visual-spatial sketchpad were particularly crucial. Contrary, the weaker performers performed better when frames were the cues. Additionally, the response time was slower with the grid featuring the wide space design.In summary the efficiency of the design depends on the specific WM performance or its individual components. Further research is needed to evaluate the relationship between multi-symbol messages and different grid cues.