Description of routes in people with intellectual disability

The ability to describe routes was assessed in participants with intellectual disability (ID) and participants without ID matched on chronological age (CA) or on mental age (MA). In two experiments, participants learned a route through a virtual environment until they reached a learning criterion. Then, they were asked to externalise their spatial knowledge in a verbal description task, a landmark recognition task or a map completion task. Results revealed that participants with ID mainly described the route as a succession of actions (“turn left”) while participants in the CA group prescribed actions referring to a landmark (“turn left at the swing”). Yet, results from the other tasks showed that individuals with ID had good landmark knowledge of the environment.