Doctor of Philosophy

dissertationThe ability to navigate without getting lost is an important aspect of quality of life. This dissertation evaluated how one mobility-related challenge-the increased demands of keeping oneself safe while walking with degraded vision (risk monitoring)- affects spatial learning. I proposed that spatial learning deficits result from attention competition. In Experiment 1, participants walked through two paths in a real-world indoor environment: one with simulated degraded vision, one with normal vision. Memory was greater when navigating with normal compared to degraded vision. Experiment 2 evaluated the role of risk-monitoring. Participants performed the learning task while guided (low risk- monitoring demands) or independently (high risk-monitoring demands). Access to visual information was equated for each path; half of the participants performed both trials with normal vision and half with simulated low vision. Memory was better when guided versus unguided, only in the low-vision condition, suggesting that mobility-risk demands affect spatial learning. In Experiment 3, participants walked while performing an auditory listening task both with simulated degraded vision and with normal vision. Auditory performance was poorer when navigating with simulated degraded vision, suggesting increased cognitive demands with degraded vision. Experiment 4 tested additional attentional resources that were needed when risk monitoring demands are higher. Participants with simulated low vision walked half the paths guided, half unguided. Auditory task error rates were higher in the unguided condition, suggesting more attention is required to navigate with high compared to low demands of risk monitoring. Experiment 5 used a mediational analysis to test whether attention task errors predicted spatial learning errors when each participant performed both tasks in a single experiment. Results from Experiment 5 replicated Experiments 2 and 4, but the mediational analysis results were not consistent with the hypothesis. These results are likely due to experimental design issues, but the causal role of attentional demands on spatial learning outcomes remains an open question. Together, these studies suggest that more attention is required and spatial learning is impaired when navigating with degraded viewing. This work also suggests that the cognitive process of risk monitoring contributes to both the decrease in attention and memory for the environment