Spatial exploration and navigation in Down syndrome and Williams syndrome.

We know little about the ability to explore and navigate large-scale space for people with intellectual disability (ID). In this cross-syndrome study, individuals with Down syndrome (DS), individuals with Williams syndrome (WS) and typically developing children (TD; aged 5-11 years) explored virtual environments with the goal of learning where everything was within the environment (Experiment 1) or to find six stars (Experiment 2). There was little difference between the WS and DS groups when the goal was simply to learn about the environment with no specific destination to be reached (Experiment 1); both groups performed at a level akin to a subset of TD children of a similar level of non-verbal ability.

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. They were then asked to externalize their spatial knowledge in a verbal description task, a landmark recognition task, or a map completion task.

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

Background: Individuals 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).

Methods: Typically developing (TD) children aged 5 to 11 years (N = 93), individuals with DS (N = 29) and individuals with WS (N = 20) were presented with a sparse and a rich VE grid maze.

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.

Assessing apathy in everyday clinical practice with the short-form Lille Apathy Rating Scale.

Background: Apathy is an invalidating behavioral disorder that must always be screened for and assessed in patients with Parkinson's disease (PD). The Lille Apathy Rating Scale (LARS) has been validated in several different contexts, but the lengthy administration time means that it is mostly recommended for research use. The aim of the present study was to validate a short form of the LARS for use in everyday practice.

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.

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 Baddeley's 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.

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).

Apathy may herald cognitive decline and dementia in Parkinson's disease.

Apathy is usually defined as a lack of motivation. It may occur as part of another disorder (notably depression and dementia) or as an isolated syndrome. In Parkinson's disease (PD), apathy is common and several studies have reported an association between this condition and more severe cognitive symptoms, such as executive dysfunction.

The Lille Apathy Rating Scale: validation of a caregiver-based version.

Apathy is reported in 16.5% to 70% of Parkinson's disease (PD) patients. Our recently developed Lille Apathy Rating Scale (LARS) has been specifically validated for patient-based assessment of apathy in PD.

Characteristics of apathy in Parkinson's disease.

The objective of this study was to use the Lille Apathy Rating Scale to assess apathy in a large population of Parkinson's disease (PD) patients and identify several different apathy profiles. One hundred fifty-nine patients with probable PD and 58 healthy controls participated in the study. Apathy was assessed using the Lille Apathy Rating Scale.

[Development of an experimental methodology: hypotheses and variables].

In this methodological paper, we present the elaboration of the experimental design, central stage of the research cycle. First, we focus on the hypothesis elaboration from the research question. Then, we detail the hypothesis operationalisation by the means of the choice of variables.