Training With Simulated Scotoma Leads to Behavioral Improvements Through at Least Two Distinct Mechanisms.

Purpose: Individuals with central vision loss due to macular degeneration (MD) often spontaneously develop a preferred retinal locus (PRL) outside the area of retinal damage, which they use instead of the fovea. Those who develop a stable PRL are more successful at coping with their vision loss. However, it is unclear whether improvements in visual performance at the PRL are specific to that retinal location or are also observed in other parts of the retina. Perceptual learning literature suggests that the retinal specificity of these effects provides insight about the mechanisms involved. Better understanding of these mechanisms is necessary for the next generation of interventions and improved patient outcomes. Methods: To address this, we trained participants with healthy vision to develop a trained retinal locus (TRL), analogous to the PRL in patients. We trained 24 participants on a visual search task using a gaze-contingent display to simulate a central scotoma. Results: Results showed retinotopically specific improvements in visual crowding only at the TRL; however, visual acuity improved in both the TRL and in an untrained retinal locus. Conclusions: These results suggest that training with an artificial scotoma involves multiple mechanistic levels, some location-specific and some not, and that simulated scotoma training paradigms likely influence multiple mechanisms simultaneously. Eye movement analysis suggests that the non-retinotopic learning effects may be related to improvements in the capability to maintain a stable gaze during stimulus presentation. This work suggests that effective interventions promoting peripheral viewing may influence multiple mechanisms simultaneously.

Oculomotor changes following learned use of an eccentric retinal locus.

People with bilateral central vision loss sometimes develop a new point of oculomotor reference called a preferred retinal locus (PRL) that is used for fixating and planning saccadic eye movements. How individuals develop and learn to effectively use a PRL is still debated; in particular, the time course of learning to plan saccades using a PRL and learning to stabilize peripheral fixation at the desired location. Here we address knowledge limitations through research describing how eye movements change as a person learns to adopt an eccentric retinal locus. Using a gaze-contingent, eye tracking-guided paradigm to simulate central vision loss, 40 participants developed a PRL by engaging in an oculomotor and visual recognition task. After 12 training sessions, significant improvements were observed in six eye movement metrics addressing different aspects involved in learning to use a PRL: first saccade landing dispersion, saccadic re-referencing, saccadic precision, saccadic latency, percentage of useful trials, and fixation stability. Importantly, our analyses allowed separate examination of the stability of target fixation separately from the dispersion and precision of the landing location of saccades. These measures explained 50% of the across-subject variance in accuracy. Fixation stability and saccadic precision showed a strong, positive correlation. Although there was no statistically significant difference in rate of learning, individuals did tend to learn saccadic precision faster than fixation stability. Saccadic precision was also more associated with accuracy than fixation stability for the behavioral task. This suggests effective intervention strategies in low vision should address both fixation stability and saccadic precision.

Effectiveness of the International Symbol of Access and inclusivity of other disability groups.

BACKGROUND: The International Symbol of Access (ISA) is recognized world-wide for designating and identifying areas which are wheelchair accessible, however its meaning has evolved to include both restricted use and universal accessibility. OBJECTIVE: This study seeks to investigate the effectiveness of the ISA in representing individuals of all impairment types. METHODS: A mixed-method survey was disseminated in the U.S. and internationally to persons without self-identified impairment and individuals of various impairment group types, including mobility, vision, hearing, and cognitive impairments, using convenience sampling (n = 981). Quantitative data was analyzed using ranking patterns and regression analysis. Qualitative data was analyzed using thematic analysis and triangulation. RESULTS: Participants with self-identified mobility impairments rated the ISA more favorably than other disability groups (p = 0.002). In addition, there is a significant correlation between age and effectiveness of the ISA, with participants rating the symbol more favorably as age increases. Common themes included association of the ISA with a mobility impairment, implications for restricted use or reserved space, and physical accessibility. CONCLUSIONS: The ISA is not effective in representing individuals with non-mobility impairments and its ambiguous nature leads to confusion for both persons with and without impairment.

Examining perceptions of existing and newly created accessibility symbols.

BACKGROUND: Symbols are used to convey messages in a clear, understandable manner, without the use of written language. The most widely recognized symbol used to denote access for persons with disabilities is the International Symbol of Access. This symbol has been criticized for its inadequate representation of disability diversity poorly representing universal design of space and products. OBJECTIVE: This descriptive study explored individual comprehension and perceptions of nine existing and newly created accessibility pictograph symbols and identified one that represented universal access to fitness equipment. METHODS: A survey was disseminated electronically and face-to-face to individuals, groups and organizations affiliated with inclusive fitness equipment, space and programming. Quantitative data was analyzed for descriptive statistics, rank order of symbols and group comparisons of rankings. Thematic analysis of open-ended question results revealed themes to enhance understanding of symbol rank order. RESULTS: 981 participants completed the survey. Symbol four, shaped as a Venn diagram containing three icons representing individuals with varying ability levels, was ranked highest with no significant differences in group comparisons between participants with and without a disability and U.S. residents versus non-U.S. residents. 85.4% of participants demonstrated accurate comprehension of this symbol. Though symbol five had the same symbol rank median value, this symbol's distribution of scores was lower. CONCLUSIONS: Participants accurately comprehended symbol four and it was identified as the highest ranked symbol representing universal access to fitness equipment. Because of symbol unfamiliarity, adoption will require education and consistency of use and placement.

Associations of Social Support and Self-Efficacy With Quality of Life in Older Adults With Diabetes.

Older adults are disproportionately affected by diabetes, which is associated with increased prevalence of cardiovascular disease, decreased quality of life (QOL), and increased health care costs. The purpose of the current study was to assess the relationships between social support, self-efficacy, and QOL in a sample of 187 older African American and Caucasian individuals with diabetes. Greater satisfaction with social support related to diabetes (but not the amount of support received) was significantly correlated with QOL. In addition, individuals with higher self-efficacy in managing diabetes had better QOL. In a covariate-adjusted regression model, self-efficacy remained a significant predictor of QOL. Findings suggest the potential importance of incorporating the self-efficacy concept within diabetes management and treatment to empower older adults living with diabetes to adhere to care. Further research is needed to determine whether improving self-efficacy among vulnerable older adult populations may positively influence QOL.