VISUAL-PERCEPTUAL FEATURES INFLUENCE EYE-HAND COUPLING BY INDIVIDUALS WITH TYPICAL DEVELOPMENT: IMPLICATIONS FOR AAC DESIGNS

Open Access
- Author:
- Liang, Jiali
- Graduate Program:
- Communication Sciences and Disorders
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- December 12, 2018
- Committee Members:
- Krista M. Wilkinson, Dissertation Advisor/Co-Advisor
Krista M. Wilkinson, Committee Chair/Co-Chair
Carol A. Miller, Committee Member
Kathryn D. R. Drager, Committee Member
Rick Gilmore, Outside Member
Robert L. Sainburg, Committee Chair/Co-Chair - Keywords:
- Eye-hand coupling
Cognitive load
Augmentative and Alternative Communication
Eye-tracking
Motor Movement - Abstract:
- Eye-hand coupling is critical for successful use of Augmentative and Alternative Communication (AAC) as users need to visually interact with the AAC display and produce motor response to activate a desired message. Results of eye-hand coupling are mainly derived from tasks with various motor demands. Previous studies examining visual and motor response in isolation have provided initial evidence that visual-perceptual features as a function of task difficulty affected time to first fixate on target, as well as time to initiate arm movement. It is still unclear how such features associated with cognitive demands would affect eye-hand coupling. Previous studies have suggested that cognitive resources are recruited to determine the eye-hand coupling pattern in response to task difficulty, suggesting a role of cognitive decision making in eye-hand coupling. I hypothesize that visual-perceptual features require substantial cognitive resources and thus would influence eye-hand coupling. I test this hypothesis by using a visual search task that presents displays with various visual-perceptual features (and thus varying task difficulty). The current data suggest an influence of cognitive-perceptual load on eye-hand coupling, such that the temporal correlation of eye and hand became stronger as cognitive load increased. Interestingly, the visual-perceptual features offered varying visual-spatial certainty such that the eye-hand delay time was shorter when symbols were clustered than when symbols were not, suggesting that the clustering feature allowed hand initiation during the search process rather than after target fixation. These results suggest a flexible temporal eye-hand relation based on task difficulty. Clinicians and manufacturers should consider displays that exert less cognitive demands on maintaining tight eye-hand coupling but offer initial facilitation for motor planning in order to improve the rate of communication using AAC.