Harry R.M. Purser

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.

Route knowledge and configural knowledge in typical and atypical development: a comparison of sparse and rich environments

BackgroundIndividuals with Down syndrome (DS) and individuals with Williams syndrome (WS) have poor navigation skills, which impact their potential to become independent. Two aspects of navigation were investigated in these groups, using virtual environments (VE): route knowledge (the ability to learn the way from A to B by following a fixed sequence of turns) and configural knowledge (knowledge of the spatial relationships between places within an environment).MethodsTypically developing (TD) children aged 5 to 11xa0years (Nu2009=u200993), individuals with DS (Nu2009=u200929) and individuals with WS (Nu2009=u200920) were presented with a sparse and a rich VE grid maze. Within each maze, participants were asked to learn a route from A to B and a route from A to C before being asked to find a novel shortcut from B to C.ResultsPerformance was broadly similar across sparse and rich mazes. The majority of participants were able to learn novel routes, with poorest performance in the DS group, but the ability to find a shortcut, our measure of configural knowledge, was limited for all three groups. That is, 59xa0% TD participants successfully found a shortcut, compared to 10xa0% participants with DS and 35xa0% participants with WS. Differences in the underlying mechanisms associated with route knowledge and configural knowledge and in the developmental trajectories of performance across groups were observed. Only the TD participants walked a shorter distance in the last shortcut trial compared to the first, indicative of increased configural knowledge across trials. The DS group often used an alternative strategy to get from B to C, summing the two taught routes together.ConclusionsOur findings demonstrate impaired configural knowledge in DS and in WS, with the strongest deficit in DS. This suggests that these groups rely on a rigid route knowledge based method for navigating and as a result are likely to get lost easily. Route knowledge was also impaired in both DS and WS groups and was related to different underlying processes across all three groups. These are discussed with reference to limitations in attention and/or visuo-spatial processing in the atypical groups.

Understanding Risky Behavior: The Influence of Cognitive, Emotional and Hormonal Factors on Decision-Making under Risk

Financial risky decisions and evaluations pervade many human everyday activities. Scientific research in such decision-making typically explores the influence of socio-economic and cognitive factors on financial behavior. However, very little research has explored the holistic influence of contextual, emotional, and hormonal factors on preferences for risk in insurance and investment behaviors. Accordingly, the goal of this review article is to address the complexity of individual risky behavior and its underlying psychological factors, as well as to critically examine current regulations on financial behavior.

Improving working memory abilities in individuals with Down syndrome: a treatment case study

Working memory (WM) skills of individuals with Down’s syndrome (DS) tend to be very poor compared to typically developing children of similar mental age. In particular, research has found that in individuals with DS visuo-spatial WM is better preserved than verbal WM. This study investigated whether it is possible to train short-term memory (STM) and WM abilities in individuals with DS. The cases of two teenage children are reported: EH, 17 years and 3 months, and AS, 15 years and 11 months. A school-based treatment targeting visuo-spatial WM was given to EH and AS for six weeks. Both prior to and after the treatment, they completed a set of assessments to measure WM abilities and their performance was compared with younger typically developing non-verbal mental age controls. The results showed that the trained participants improved their performance in some of the trained and non-trained WM tasks proposed, especially with regard to the tasks assessing visuo-spatial WM abilities. These findings are discussed on the basis of their theoretical, educational, and clinical implications.

Definitions versus categorization: assessing the development of lexico-semantic knowledge in Williams syndrome

BACKGROUNDnWilliams syndrome (WS) is associated with relatively strong language abilities despite mild to moderate intellectual disability, particularly when language is indexed by vocabulary.nnnAIMSnThe aim of the study was twofold: (1) to investigate whether reported lexical anomalies in WS can be explained with reference to anomalous semantic development; and (2) to assess whether receptive vocabulary skills in WS, a relative strength, are underpinned by commensurate semantic knowledge.nnnMETHODS & PROCEDURESnThe development of lexical-semantic knowledge was investigated in 45 typically developing individuals (chronological age range = 5-10 years, mental age range = 5-13 years) and 15 individuals with WS (chronological age range = 12-50 years, mental age range = 4-17 years) by means of (1) a categorization task and (2) a definitions task, which was expected to make additional metacognitive demands.nnnOUTCOMES & RESULTSnAt younger ages, the performance level of typically developing individuals and individuals with WS did not differ on the definitions task. However, the WS groups ability to define words fell away from the level predicted by the typically developing group at older ages, as more sophisticated definitions were expected. The results of the categorization task indicated that individuals with WS had less lexical-semantic knowledge than expected given their level of receptive vocabulary, although from this lower level the knowledge then developed at a similar rate to that found in typical development.nnnCONCLUSIONS & IMPLICATIONSnIt is concluded, first, that conventional vocabulary measures may overestimate lexical-semantic knowledge in WS; and, second, concerns about the metacognitive demands of the definitions task when used with atypical populations may be well founded.

VECUDÉJÀ VÉCU AND DÉJÀ VISITÉ: SIMILARITIES AND DIFFERENCES FURTHER RESULTS FROM AN ONLINE QUESTIONNAIRE

&NA; Over an 8‐year period, an online questionnaire, devised as a pilot project, collected exploratory data in order to compare the particularities of déjà vécu (i.e., event related) experiences with those of déjà visité (i.e., location related). In a previous article it was shown that there are sufficient differences in the results for these two experiences to warrant considering them as being separate entities. Here, additional analyses have established a number of relationships that differ across the two phenomena. Their elucidation will require further investigations with improved research instruments and the studied population will have to be broader based in order to establish if the relationships determined here will be found to be true in the general population.