Navigation and Exploration; strategy use in typical children, Williams syndrome and Down syndrome.

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

Integrative Statement

Introduction and Hypotheses
Our ability to navigate successfully in large scale space is crucial to everyday living; a poor ability to find your way has a significant impact on independence. The most sophisticated form of wayfinding involves knowledge of the spatial relationships between places within an environment, known as configural knowledge or having a ‘cognitive map’. One way in which we develop configual knowledge is through exploration. In typical children, during exploration older children show increased use of distant landmarks, better landmark choices and increased visual scanning of their surroundings, relative to younger children. We were interested in exploration strategies in typically developing (TD) children, and in Down syndrome (DS) and Williams syndrome (WS), for whom configural knowledge is impaired. We hypothesised that exploration would be less effective and less strategic in the DS and WS groups than in TD children, with the largest deficit in the DS group.

Study population
Typically developing (TD) children aged 5-12 years (N=91), individuals with Down syndrome (N=36) and individuals with Williams syndrome (N=21).
Method
Participants explored three novel virtual reality towns. Each town had ten blocks of buildings, three distant landmarks and 40 landmarks. Free exploration was measured in Town 1. Participants were asked to “learn as much as you can about where everything is in the town” within three minutes. Goal oriented exploration was measured in Towns 2 and 3. Participants attempted to locate six stars within three minutes (five trials/ town). Towns were displayed with or without the presence of a “Satellite-Navigation”-style overhead map which showed their location from an overhead viewpoint (Figure 1). We also measured verbal (British Picture Vocabulary Scale) and non-verbal (Raven’s Coloured Progressive Matrices) IQ.
Results
In Town 1 (free exploration) the TD group had significantly longer path lengths (length of the walked route) and significantly less dwell time (amount of time stood still) than the DS and WS groups. In Towns 2 and 3 (goal oriented exploration), the TD group collected significantly more stars, in a shorter time than the DS group, and the same number of stars, but in a shorter time, compared to the WS group. There were no differences between the DS and WS groups. The addition of an overhead map did not improve performance, which suggests that providing people with a map/GPS when exploring, is not useful. Learning was observed across trials for the TD group (more stars collected, shorter completion time). Learning was limited in the WS group, and not evident for the DS group. Longer path lengths were detrimental to success (number of stars collected) for the DS and WS groups only, which could indicate insufficient exploration organisation. Verbal IQ was important for the TD group only, suggestive of a verbal labelling strategy. Dwell time was negatively associated with success for all groups. Furthermore, poor non-verbal ability limited performance on later trials, but not initial trials for the WS group.

Authors

• Emily K. Farran, University College London
  Presenting Author

• Kerry D Hudson, University Colllege London
  Non-Presenting Author

• Melanie Facon, Université de Lille
  Non-Presenting Author

• Hayley White, Royal Holloway, University of London
  Non-Presenting Author

• Katie A. Gilligan, UCL Institute of Education
  Non-Presenting Author

• Hannah Ward, University Colllege London
  Non-Presenting Author

• Pascal Sockeel, Université de Lille
  Non-Presenting Author

• Daniel Mellier, Université de Rouen
  Non-Presenting Author

• Mark Blades, University of Sheffield
  Non-Presenting Author

• Yannick Courbois, Université de Lille
  Non-Presenting Author