Abstract:
Down syndrome (DS) is a neurodevelopmental disorder associated with many cognitive weaknesses, including certain aspects of wayfinding. There are several theoretical reasons, such as abnormal brain development and similar weaknesses in smaller scales of space, that these deficits include developing survey knowledge of an environment. However, few studies have directly investigated this ability. The current study compared people with DS to typical adults matched on chronological age and typical children matched on the KBIT-II Matrices Subtest on a measure of survey knowledge. More specifically, an experimenter exposed participants to a novel virtual environment, and then were asked to find a specific target on their own. The total distance traveled and time taken to find the target served as dependent variables. The task was repeated three times, such that the participants navigated to the target after the experimenter showed them the environment once, two additional times, and again after two more times. Participants in both comparison groups demonstrated linear improvement across the three trials, with the children travelling a longer distance and taking longer to find the target at each trial compared to the adults. Participants with DS performed similarly to the typical children after the initial exposure, but did not demonstrate any learning across the trials, thereby resulting in a worse performance than both control groups on subsequent trials. The findings suggest that survey representations are impaired in DS, specifically in the ability to improve these representations over time. This has important implications for developing wayfinding interventions, and for understanding how these individuals learn about new environments.
