Abstract
Visual supports are commonly used to enhance communication in individuals with developmental disorders, including Down syndrome (DS). Augmentative and Alternative Communication (AAC) supports display customized symbols designed to facilitate communication. Until recently, little research has focused on what properties of the symbols or their arrangement facilitates the use of AAC tools. This study used eye-tracking to investigate how different layouts of symbol icons altered the visual search process. Five participants with DS and 25 typically developing young adults participated. In each trial of the experiment, observers were cued to search for a target symbol in a 16-symbol display (19.2 deg × 14.2 deg at the viewing distance of 65 cm). Four different symbol layouts were evaluated, with 8 trials per layout. Eye position data was collected at 60 Hz and fixations on the symbols or the background were calculated using standard algorithms. The results showed that the participants with DS made significantly more eye movements than typically developing participants before making a decision about the position of the cued target. Among the 4 layouts, both groups of participants made significantly fewer eye fixations to the annular arrangement with emotions clustered in the middle (Clock condition, see Figure 1 in the supplementary material) than when presented with a grid arrangement based on the standard of care (SOC condition). Additionally, once participants fixated the target symbol in the Clock condition, they were less likely to look toward distractors than in the SOC condition. These results provide evidence that altering the size and arrangement of visual symbols in AAC-like displays can effectively alter visual search behavior. Understanding how people search for visual information may help optimize the utility of visual communication supports for individuals with special needs.
Acknowledgement: NICHD 1R01HD083381