Parameters for design of computer-based program for people with mental retardation

• Main Author: Wong, Wing Kai
• Format: Dissertation
• Language: English
• Subjects: health sciences, mental health; health sciences, rehabilitation and therapy
• ISBN: 0549442081; 9780549442080

This research aimed to explore the mechanisms which hinder people with mental retardation from effectively using the technological products. The research question of the study I was: what was the performance level of the people with mental retardation on operating a common human-computer interface program? 57 people with mild (n=30) or moderate ( n=27) mental retardation (Mean Age=17.2 years (SD=3.3)) participated in an Internet Explorer (IE) competence test. It was composed of 16 IE tasks (161 subtasks) in which performances were evaluated against a 4-point scale. The "general motor function" (B=-3.43, SE=1.59) and "use customized bookmark" (B=-3.54, SE=1.06) were the most predictive of the participants' performance (chi2=38.35, df=2, p<0.001). The research question of the study 2 was: what were the core cognitive abilities predictive of these people's performance level? 62 people with mild ( n=33) or moderate (n=29) mental retardation (Mean Age: 17.4 years (SD=6.0)) participated in the IE competence test and completed 13 tests on attention, visual-spatial, memory, executive functions, language, and sensori-motor functions. Results indicated that attention and visual search function (R2 = 49.7%), fine motor functions (R 2 5.8%) and Chinese word recognition functions (R2= 3.2%) were the best three predictors on overall IE performance [total R 2 = 0.59, Model F(3, 58) =27.40, p<0.001].
The question addressed by Study 3 was: what were the underlying visual search mechanisms hindered these people from being competent on operating IE? A total 24 people with mild or moderate mental retardation (Mean Age=19.0 years (SD=5.4)), and 30 normal counterparts (Mean Age=20.8 years (SD=1.9)) were recruited. The task required the participant to visually search the target square (one) or squares (two) and indicate as quickly as possible the number of target square(s) which they found. We hypothesized that their search performances would be modulated by the distances (close: I visual lobe, medium: 1.5 visual lobes, and far: 2 visual lobes) and orientation (vertical, horizontal and oblique) between the two target stimuli. Their eye movements were recorded. Their visual lobe areas and shape characteristics were measured with the Visual Lobe Measurement System (VILOMS). Results indicated that participants with mental retardation had significantly smaller visual lobe areas ( t(38)=4.13, p<0.001), and less likely using consistent search strategies (p<0.001) and lower performances (ps<0.05) on the visual search task, than their normal counterpart. The results on testing the Distance x Orientation effects on the scanpath duration and overall fixation duration indicated that, the interaction effect was only significant for normal participants (F(4,26)=4.85, p=0.005 and F(4,26)=4.65, p =0.006 respectively). People with mental retardation had only significant main effects on Distance (F(2,22)=11.81, p<0.001 and F(2 22)=7.71, p=0.003) and Orientation (F(2,22)=5.97, p=0.008 and F(2,22)=4.91, p =0.017).
Findings suggest that a plausible account of why people with mental retardation would have problems when using the human-machine interface. Results on Distance x Orientation effects offer nsights into the possibility of using these as guidelines for design of human-machine interface for people with mental retardation.