Yannick Courbois

Route Learning and Shortcut Performance in Adults with Intellectual Disability: A Study with Virtual Environments

The ability to learn routes though a virtual environment (VE) and to make a novel shortcut between two locations was assessed in 18 adults with intellectual disability and 18 adults without intellectual disability matched on chronological age. Participants explored two routes (A ⇔ B and A ⇔ C) until they reached a learning criterion. Then, they were placed at B and were asked to find the shortest way to C (B ⇔ C, five trials). Participants in both groups could learn the routes, but most of the participants with intellectual disability could not find the shortest route between B and C. However, the results also revealed important individual differences within the intellectual disability group, with some participants exhibiting more efficient wayfinding behaviour than others. Individuals with intellectual disability may differ in the kind of spatial knowledge they extract from the environment and/or in the strategy they use to learn routes.

Wayfinding Behaviour in Down Syndrome: A Study with Virtual Environments.

The aim of this study was to assess wayfinding abilities in individuals with Down syndrome (DS). The ability to learn routes though a virtual environment (VE) and to make a novel shortcut between two locations was assessed in individuals with DS (N=10) and control participants individually matched on mental age (MA) or chronological age (CA). The results showed that most of the participants with DS were able to learn routes through the VE, even though they needed more trials than the CA controls to reach the learning criterion. However, they did not show flexible wayfinding behaviour because they were unable to find a shortcut between two known locations (unlike the CA controls). The results suggest that most individuals with DS can acquire knowledge about specific routes, but are unable to integrate that knowledge into a configurational understanding of the environment.

The development of route learning in Down syndrome, Williams syndrome and typical development: investigations with virtual environments

The ability to navigate new environments has a significant impact on the daily life and independence of people with learning difficulties. The aims of this study were to investigate the development of route learning in Down syndrome (N = 50), Williams syndrome (N = 19), and typically developing children between 5 and 11 years old (N = 108); to investigate use of landmarks; and to relate cognitive functions to route-learning ability in these groups. Overall, measures of attention and long-term memory were strongly associated with route learning, even once non-verbal ability was controlled for. All of the groups, including 5- to 6-year-old TD children, demonstrated the ability to make use of all landmark types to aid route learning; those near junctions, those further from junctions, and also distant landmarks (e.g. church spire, radio mast). Individuals with WS performed better than a matched subset of TD children on more difficult routes; we suggest that this is supported by relatively strong visual feature recognition in the disorder. Participants with DS who had relatively high levels of non-verbal ability performed at a similar level to TD participants.

Short-term memory, executive control, and children’s route learning

The aim of this study was to investigate route-learning ability in 67 children aged 5 to 11years and to relate route-learning performance to the components of Baddeleys model of working memory. Children carried out tasks that included measures of verbal and visuospatial short-term memory and executive control and also measures of verbal and visuospatial long-term memory; the route-learning task was conducted using a maze in a virtual environment. In contrast to previous research, correlations were found between both visuospatial and verbal memory tasks-the Corsi task, short-term pattern span, digit span, and visuospatial long-term memory-and route-learning performance. However, further analyses indicated that these relationships were mediated by executive control demands that were common to the tasks, with long-term memory explaining additional unique variance in route learning.

Mental Rotation in Williams Syndrome: An Impaired Ability

Typically developing young children and individuals with intellectual disabilities often perform poorly on mental rotation tasks when the stimulus they are rotating lacks a salient component. However, performance can be improved when salience is increased. The present study investigated the effect of salience on mental rotation performance by individuals with Williams syndrome. Individuals with Williams syndrome and matched controls were presented with two versions of a mental rotation task: a no salient component condition and a salient component condition. The results showed that component salience did not benefit individuals with Williams syndrome in the same manner as it did controls.

Colour as an Environmental Cue when Learning a Route in a Virtual Environment: Typical and Atypical Development.

Typically developing (TD) 6-year-olds and 9-year-olds, and older children and adults with Williams syndrome (WS) navigated through brick-wall mazes in a virtual environment. Participants were shown a route through three mazes, each with 6 turns. In each maze the floor of each path section was a different colour such that colour acted as an environmental cue. The colours employed were either easy to verbalise (focal colours) or difficult to verbalise (non-focal colours). We investigated whether participants would verbally code the colour information in the focal colour condition only, and whether this facilitated route-learning. All groups could learn the routes; the WS group required more learning trials to learn the route and achieved lower memory scores than both of the TD groups. Despite this, all groups showed the same pattern of results. There was no effect of condition on the ability to learn the maze. However, when asked which colours featured in each route, higher memory scores were achieved for the focal colour (verbalisable) than the non-focal colour (non-verbalisable) condition. This suggests that, in both young children and individuals with WS, once a route has been learnt, the nature of the environmental cues within it can impact an individuals representation of that route.

Do individuals with intellectual disability select appropriate objects as landmarks when learning a new route

BACKGROUND The present study was aimed at investigating the selection of landmarks by individuals with intellectual disability (ID). The hypothesis was that they would be less efficient than individuals without IDs in the selection of landmarks when learning a new route. METHODS The experiment took place in a natural setting with a group of participants with ID and a group of control participants matched by chronological age. The participants were first guided along a route situated in an unfamiliar district. Then, they had to guide the experimenter along the route while pointing to all the objects and features they found useful for wayfinding. RESULTS The designated objects were categorised as a function of their landmarks properties. There were significant differences between the two groups for non-permanent landmarks, distant landmarks and non-unique landmarks. The two groups selected landmarks near intersections in the same proportions. However, the individuals with ID selected more non-unique landmarks and less textual signage than the control group at these decision points. CONCLUSION Individuals with ID seem to be less efficient than individuals without disability in landmark selection. This may limit their wayfinding abilities in their day-to-day travelling. This may also account for their difficulties in obtaining the kind of spatial knowledge which relates to the configural structure of their environment.

Encouraging 5-year olds to attend to landmarks: a way to improve children's wayfinding strategies in a virtual environment

Wayfinding is defined as the ability to learn and remember a route through an environment. Previous researchers have shown that young children have difficulties remembering routes. However, very few researchers have considered how to improve young childrens wayfinding abilities. Therefore, we investigated ways to help children increase their wayfinding skills. In two studies, a total of 72 5-year olds were shown a route in a six turn maze in a virtual environment and were then asked to retrace this route by themselves. A unique landmark was positioned at each junction and each junction was made up of two paths: a correct path and an incorrect path. Two different strategies improved route learning performance. In Experiment 1, verbally labeling on-route junction landmarks during the first walk reduced the number of errors and the number of trials to reach a learning criterion when the children retraced the route. In Experiment 2, encouraging children to attend to on-route junction landmarks on the first walk reduced the number of errors when the route was retraced. This was the first study to show that very young children can be taught route learning skills. The implications of our results are discussed.

Mental rotation of unfamiliar stimuli by teenagers with mental retardation: role of feature salience.

Teenagers with mental retardation and two groups of children without mental retardation matched on MA or CA carried out mental rotation tasks of unfamiliar stimuli. Three shapes composed of four arms were used. For each shape, there was a version with a salient feature (F+), and a version with no salient feature (F-). Results showed that teenagers with mental retardation could perform mental rotation tasks with unfamiliar stimuli. However, they had a steeper increase in error rate for F- stimuli than did the MA and CA groups. Individuals with mental retardation may have difficulties in performing mental rotation tasks when stimuli have no feature with a salient axis of elongation.

A cross-sectional analysis of developmental trajectories of vocabulary comprehension among children and adolescents with Down syndrome or intellectual disability of undifferentiated aetiology

ABSTRACT Background In this work we sought to expand our knowledge of developmental trajectories of subcomponents of the language systems of individuals with intellectual disability (ID). We aimed to explore how general and relational vocabularies evolve as a function of cognitive level. Method Developmental trajectories of general and relational vocabulary comprehension were compared among typically developing (TD) children and children and adolescents with ID of undifferentiated aetiology (UND) or Down syndrome (DS). Results Comparisons between TD participants and participants with UND showed no interaction between cognitive level and diagnostic status for general vocabulary, and only a very weak interaction for relational vocabulary. Comparisons between TD participants and participants with DS failed to reveal group-specific trajectories. Performance in general vocabulary was higher than in relational vocabulary for participants with UND and DS. Conclusion The developmental trajectories of vocabulary appear to be globally comparable for participants with or without ID.