Judicious Arrangement of Symbols on a Simulated Augmentative and Alternative Communication Display Optimizes Visual Attention by Individuals With Down Syndrome.

PURPOSE: Aided augmentative and alternative communication (AAC) displays are often designed as symmetrical row-column grids, with each square in the grid containing a symbol. To maximize vocabulary on displays, symbols are often placed close to one another, and background color cuing is used to signal/differentiate symbols across different grammatical categories. However, from a visual and developmental standpoint, these display features (close-set symbols and use of background color cues) may not be optimal. In particular, placing symbols quite close together may result in visual crowding, in which individual symbols cannot be distinguished due to the presence of many neighbors, or flankers. This research sought to examine the role of display arrangement and background color cuing on the efficiency of visual attention during search.

METHOD: Ten adolescents and adults with Down syndrome underwent a visual search task while a research-based eye tracking system recorded their patterns of visual attention. Participants searched for symbol targets on displays with varying levels of visual crowding and background color cuing.

RESULTS

Spatial arrangements that reduced visual crowding and that used the spatial organization to cue the grammatical category of symbols resulted in significantly fewer fixations to nonrelevant distracters during search and reduced the likelihood of fixations away from the target once it was located. Background color was helpful in reducing the latency to find the target.

DISCUSSION: Spatial cues may offer a powerful means to maximize the efficiency of search within AAC displays. Background color cuing may facilitate speed to locate targets in these older individuals. Implications for AAC design, as well as future avenues for maximizing (growing) vocabulary, are discussed.