Acquisition of Route and Survey Knowledge during Wayfinding by Individuals with Down Syndrome

• In Event: 2-083 - How do navigational skills develop in typical and atypical populations?

Integrative Statement

Introduction: Our research focuses on various aspects of navigation/wayfinding of individuals with Down syndrome (DS). DS is the most common genetic syndrome resulting in intellectual disability. One goal of our research on persons with DS is to promote the highest degree of independent living that is possible. Wayfinding encompasses the skills associated with efficiently navigating the environment and is integral to independent functioning. Recent evidence from studies of brain structure and function identifies the hippocampus as a brain region that impacted by DS. Given the role of the hippocampus in spatial learning, persons with DS would be expected to exhibit specific deficiencies with wayfinding and related activities.
General Method: Across multiple studies, we had participants with DS perform a wayfinding task in a simple virtual environment (i.e., computer presented route) or real environment (a series of hallways) and compare their learning of the route and corresponding information about the environment to persons with Intellectual Disability and not DS (mixed ID), and to typically developing (TD) children with whom they were matched on nonverbal ability. Routes incorporated 8 – 12 choice points with unique objects (appropriate for the displays) at each choice point. Choice points had two or three options and participants could choose straight, left, or right turns. Participants were first directed along the route (using arrows) or shown the correct route by the experimenter. Then, participants were given the opportunity to travel and learn the route on their own. Across the various studies, number of participants per group ranged from 16 to 28 and nonverbal ability ranged from 4.0 to 10.0 years of age. Participants with DS were between 10 and 25 years.
General Results: Results from the several experiments indicated that participants with DS committed more errors during route learning than did TD children and participants with mixed ID. Although the difference was greater when learning a virtual environment, learning a real-world route was also much slower for participants with DS than for TD children. TD children performed at ceiling by the third attempt, whereas the participants with DS showed little improvement across the same number of trials. Further, although route learning appears to be a consistent problem, acquisition of survey knowledge about the traveled environment was more mixed. When asked to identify the overall layout of a traveled environment, participants with DS were less likely to identify a depiction of the route. However, when asked to point to an unseen object along a direct path they performed similarly to TD children. The two groups also performed similarly when locating a shortcut between two points experienced during the route learning task, although fewer participants with DS reached criterion to attempt the shortcut task.
Discussion: It appears that route learning is a major difficulty for participants with DS. Even though some aspects of acquiring survey knowledge are also impaired, other aspects may be preserved relative to TD children. In our discussion, we consider the roles of explicit and implicit spatial learning in explaining this pattern of results.

Authors

• Edward Merrill, University of Alabama
  Presenting Author

• Frances Conners, University of Alabama
  Non-Presenting Author

• Beverly Roskos, University of Alabama
  Non-Presenting Author

• Trent Robinson, University of Alabama
  Non-Presenting Author

• Zachary Himmelberger, University of Alabama
  Non-Presenting Author

• Yingying Yang, Montclair State University
  Non-Presenting Author