Ecological validity of virtual reality daily living activities screening for early dementia: longitudinal study

Background: Dementia is a multifaceted disorder that impairs cognitive functions, such as memory, language, and executive functions necessary to plan, organize, and prioritize tasks required for goal-directed behaviors. In most cases, individuals with dementia experience difficulties interacting with physical and social environments. The purpose of this study was to establish ecological validity and initial construct validity of a fire evacuation Virtual Reality Day-Out Task (VR-DOT) environment based on performance profiles as a screening tool for early dementia. Objective: The objectives were (1) to examine the relationships among the performances of 3 groups of participants in the VR-DOT and traditional neuropsychological tests employed to assess executive functions, and (2) to compare the performance of participants with mild Alzheimer’s-type dementia (AD) to those with amnestic single-domain mild cognitive impairment (MCI) and healthy controls in the VR-DOT and traditional neuropsychological tests used to assess executive functions. We hypothesized that the 2 cognitively impaired groups would have distinct performance profiles and show significantly impaired independent functioning in ADL compared to the healthy controls. Methods: The study population included 3 groups: 72 healthy control elderly participants, 65 amnestic MCI participants, and 68 mild AD participants. A natural user interface framework based on a fire evacuation VR-DOT environment was used for assessing physical and cognitive abilities of seniors over 3 years. VR-DOT focuses on the subtle errors and patterns in performing everyday activities and has the advantage of not depending on a subjective rating of an individual person. We further assessed functional capacity by both neuropsychological tests (including measures of attention, memory, working memory, executive functions, language, and depression). We also evaluated performance in finger tapping, grip strength, stride length, gait speed, and chair stands separately and while performing VR-DOTs in order to correlate performance in these measures with VR-DOTs because performance while navigating a virtual environment is a valid and reliable indicator of cognitive decline in elderly persons. Results: The mild AD group was more impaired than the amnestic MCI group, and both were more impaired than healthy controls. The novel VR-DOT functional index correlated strongly with standard cognitive and functional measurements, such as mini-mental state examination (MMSE; rho=0.26, P=.01) and Bristol Activities of Daily Living (ADL) scale scores (rho=0.32, P=.001). Conclusions: Functional impairment is a defining characteristic of predementia and is partly dependent on the degree of cognitive impairment. The novel virtual reality measures of functional ability seem more sensitive to functional impairment than qualitative measures in predementia, thus accurately differentiating from healthy controls. We conclude that VR-DOT is an effective tool for discriminating predementia and mild AD from controls by detecting differences in terms of errors, omissions, and perseverations while measuring ADL functional ability.

Can a novel computerized cognitive screening test provide additional information for early detection of Alzheimer's disease?

BACKGROUND: Virtual reality testing of everyday activities is a novel type of computerized assessment that measures cognitive, executive, and motor performance as a screening tool for early dementia. This study used a virtual reality day-out task (VR-DOT) environment to evaluate its predictive value in patients with mild cognitive impairment (MCI). METHODS: One hundred thirty-four patients with MCI were selected and compared with 75 healthy control subjects. Participants received an initial assessment that included VR-DOT, a neuropsychological evaluation, magnetic resonance imaging (MRI) scan, and event-related potentials (ERPs). After 12 months, participants were assessed again with MRI, ERP, VR-DOT, and neuropsychological tests. RESULTS: At the end of the study, we differentiated two subgroups of patients with MCI according to their clinical evolution from baseline to follow-up: 56 MCI progressors and 78 MCI nonprogressors. VR-DOT performance profiles correlated strongly with existing predictive biomarkers, especially the ERP and MRI biomarkers of cortical thickness. CONCLUSIONS: Compared with ERP, MRI, or neuropsychological tests alone, the VR-DOT could provide additional predictive information in a low-cost, computerized, and noninvasive way.

Understanding the performance of the FLake model over two African Great Lakes

The ability of the one-dimensional lake model FLake to represent the mixolimnion temperatures for tropical conditions was tested for three locations in East Africa: Lake Kivu and Lake Tanganyika's northern and southern basins. Meteorological observations from surrounding automatic weather stations were corrected and used to drive FLake, whereas a comprehensive set of water temperature profiles served to evaluate the model at each site. Careful forcing data correction and model configuration made it possible to reproduce the observed mixed layer seasonality at Lake Kivu and Lake Tanganyika (northern and southern basins), with correct representation of both the mixed layer depth and water temperatures. At Lake Kivu, mixolimnion temperatures predicted by FLake were found to be sensitive both to minimal variations in the external parameters and to small changes in the meteorological driving data, in particular wind velocity. In each case, small modifications may lead to a regime switch, from the correctly represented seasonal mixed layer deepening to either completely mixed or permanently stratified conditions from similar to 10 m downwards. In contrast, model temperatures were found to be robust close to the surface, with acceptable predictions of near-surface water temperatures even when the seasonal mixing regime is not reproduced. FLake can thus be a suitable tool to parameterise tropical lake water surface temperatures within atmospheric prediction models. Finally, FLake was used to attribute the seasonal mixing cycle at Lake Kivu to variations in the near-surface meteorological conditions. It was found that the annual mixing down to 60m during the main dry season is primarily due to enhanced lake evaporation and secondarily to the decreased incoming long wave radiation, both causing a significant heat loss from the lake surface and associated mixolimnion cooling.

Microwave radiometer to retrieve temperature profiles from the surface to the stratopause

TEMPERA (TEMPERature RAdiometer) is a new ground-based radiometer which measures in a frequency range from 51–57 GHz radiation emitted by the atmosphere. With this instrument it is possible to measure temperature profiles from ground to about 50 km. This is the first ground-based instrument with the capability to retrieve temperature profiles simultaneously for the troposphere and stratosphere. The measurement is done with a filterbank in combination with a digital fast Fourier transform spectrometer. A hot load and a noise diode are used as stable calibration sources. The optics consist of an off-axis parabolic mirror to collect the sky radiation. Due to the Zeeman effect on the emission lines used, the maximum height for the temperature retrieval is about 50 km. The effect is apparent in the measured spectra. The performance of TEMPERA is validated by comparison with nearby radiosonde and satellite data from the Microwave Limb Sounder on the Aura satellite. In this paper we present the design and measurement method of the instrument followed by a description of the retrieval method, together with a validation of TEMPERA data over its first year, 2012.

Digital multitext editions from scratch to electronic performance. Transcription and collation routines transformed in a flexible database system

The poster demonstrates the preparatory steps of a digital multi-text edition that are abstracted from the experiences made in the Parzival Project, based at the University of Bern, the Berlin-Brandenburg Academy of Sciences and the University of Erlangen. This edition of Wolfram von Eschenbach’s German Grail novel, written shortly after 1200 and transmitted during several centuries in ca. hundred witnesses, has now been completed by more than a half of the textual corpus. As the text is transmitted in medieval manuscripts the witnesses have to be transcribed according to specific encoding rules. The transcriptions then are collated following certain ideas and concepts of how the transmission process could have developed. The transcriptions and collations finally have to be transferred to a digital edition that allows the users to explore the characteristics of single witnesses as well as the history of a text, which is delivered in variants and in different versions. A dynamically organized database offering various components and adapted to the needs of diverse user-profiles is nowadays the right tool for this purpose.

Group abilities, individual group-efficacy beliefs and performance motivation: A mediation analysis

Introduction Research has shown that individuals infer their group-efficacy beliefs from the groups’ abilities to perform in specific tasks. Group abilities also seem to affect team members’ performance motivation adding a psychological advantage to teams already high on task relevant abilities. In a recent study we found the effect of group abilities on individual performance motivation to be partially mediated by the team members’ individual group-efficacy beliefs which is an example of how attributes on a group-level can be affecting individual-level parameters. Objectives The study aimed at testing the possibility to reduce the direct and mediated effects of low group abilities on performance motivation by augmenting the visibility of individual contributions to group performances via the inclusion of a separate ranking on individual performances. Method Forty-seven students (M=22.83 years, SD=2.83, 34% women) of the University of Bern participated in the study. At three collection points (t1-3) subjects were provided information about fictive team members with whom they had to imagine performing a group triathlon. Three values (low, medium, high) of the other team members’ abilities to perform in their parts of the triathlon (swimming and biking) were combined in a 3x3 full factorial design yielding nine groups with different ability profiles. At t1 subjects were asked to rate their confidence that the teams would perform well in the triathlon task, at t2 and t3 subjects were asked how motivated they were to perform at their best in the respective groups. At t3 the presence of an individual performance ranking was mentioned in the cover story. Mixed linear models (SPSS) and structural equation models for complex survey data (Mplus) were specified to estimate the effects of the individual performance rankings on the relationship between group-efficacy beliefs and performance motivation. Results A significant interaction effect for individual group-efficacy beliefs and the triathlon condition on performance motivation was found; the effect of group-efficacy beliefs on performance motivation being smaller with individual performance rankings available. The partial mediation of group attributes on performance motivation by group-efficacy beliefs disappeared with the announcement of individual performance rankings. Conclusion In teams low in task relevant abilities the disadvantageous effect of group-efficacy beliefs on performance motivation might be reduced by providing means of evaluating individual performances apart from a group’s overall performance. While it is believed that a common group goal is a core criterion for a well performing sport group future studies should also aim at the possible benefit of individualized goal setting in groups.

Group abilities, individual group-efficacy beliefs and performance motivation: A mediation analysis

Introduction Research has shown that individuals infer their group-efficacy beliefs from the groups’ abilities to perform in specific tasks. Group abilities also seem to affect team members’ performance motivation adding a psychological advantage to teams already high on task relevant abilities. In a recent study we found the effect of group abilities on individual performance motivation to be partially mediated by the team members’ individual group-efficacy beliefs which is an example of how attributes on a group-level can be affecting individual-level parameters. Objectives The study aimed at testing the possibility to reduce the direct and mediated effects of low group abilities on performance motivation by augmenting the visibility of individual contributions to group performances via the inclusion of a separate ranking on individual performances. Method Forty-seven students (M=22.83 years, SD=2.83, 34% women) of the University of Bern participated in the study. At three collection points (t1-3) subjects were provided information about fictive team members with whom they had to imagine performing a group triathlon. Three values (low, medium, high) of the other team members’ abilities to perform in their parts of the triathlon (swimming and biking) were combined in a 3x3 full factorial design yielding nine groups with different ability profiles. At t1 subjects were asked to rate their confidence that the teams would perform well in the triathlon task, at t2 and t3 subjects were asked how motivated they were to perform at their best in the respective groups. At t3 the presence of an individual performance ranking was mentioned in the cover story. Mixed linear models (SPSS) and structural equation models for complex survey data (Mplus) were specified to estimate the effects of the individual performance rankings on the relationship between group-efficacy beliefs and performance motivation. Results A significant interaction effect for individual group-efficacy beliefs and the triathlon condition on performance motivation was found; the effect of group-efficacy beliefs on performance motivation being smaller with individual performance rankings available. The partial mediation of group attributes on performance motivation by group-efficacy beliefs disappeared with the announcement of individual performance rankings. Conclusion In teams low in task relevant abilities the disadvantageous effect of group-efficacy beliefs on performance motivation might be reduced by providing means of evaluating individual performances apart from a group’s overall performance. While it is believed that a common group goal is a core criterion for a well performing sport group future studies should also aim at the possible benefit of individualized goal setting in groups.

Motivational profiles of sport event volunteers.

Aim of the study Due to the valuable contribution made by volunteers to sporting events, a better understanding of volunteers’ motivation is imperative for event managers in order to develop effective volunteer re-cruitment and retention strategies. The adoption of working conditions and task domains to the mo-tives and needs of volunteers is one of the key challenges in volunteer management. Conversely, an ignorance of the motives and needs of volunteers could negatively affect their performance and attitude, which will have negative consequences for the execution of events (Strigas & Jackson, 2003). In general, the motives of volunteers are located on a continuum between selflessness (e.g. helping others), and self-interest (e.g. pursuing one’s own interests). Furthermore, it should take into account that volunteers may be motivated by more than one need or goal, and therefore, configure different bundles of motives, resulting in heterogeneous types of motives for voluntary engagement (Dolnicar & Randle, 2007). Despite the extensive number of studies on the motives of sport event volunteers, only few studies focus on the analysis of individual motive profiles concerning volun-teering. Accordingly, we will take a closer look at the following questions: To what extent do volun-teers at sporting events differ in the motives of their engagement, and how can the volunteers be ade-quately classified? Theoretical Background According to the functional approach, relevant subjective motives are related to the outcomes and consequences that volunteering is supposed to lead to and to produce. This means, individuals’ mo-tives determine which incentives are anticipated in return for volunteering (e.g. increase in social contacts), and are important for engaging in volunteering, e.g. the choice between different oppor-tunities for voluntary activity, or different tasks (Stukas et al., 2009). Additionally, inter-individual differences of motive structures as well as matching motives in the reflections of voluntary activities will be considered by using a person-oriented approach. In the person-oriented approach, it is not the specific variables that are made the entities of investigation, but rather persons with a certain combination of characteristic features (Bergmann et al., 2003). Person-orientation in the field of sports event volunteers, it is therefore essential to implement an orientation towards people as a unit of analysis. Accordingly, individual motive profiles become the object of investigation. The individ-ual motive profiles permit a glimpse of intra-individual differences in the evaluation of different motive areas, and thus represent the real subjective perspective. Hence, a person will compare the importance of individual motives for his behaviour primarily in relation to other motives (e.g. social contacts are more important to me than material incentives), and make fewer comparisons with the assessments of other people. Methodology, research design and data analysis The motives of sports event volunteers were analysed in the context of the European Athletics Championships 2014 in Zürich. After data cleaning, the study sample contained a total of 1,169 volunteers, surveyed by an online questionnaire. The VMS-ISA scale developed by Bang and Chel-ladurai (2009) was used and replicated successfully by a confirmatory factor analysis. Accordingly, all seven factors of the scale were included in the subsequent cluster analysis to determine typical motive profiles of volunteers. Before proceeding with the cluster analysis, an intra-individual stand-ardization procedure (according to Spiel, 1998) was applied to take advantage of the intra-individual relationships between the motives of the volunteers. Intra-individual standardization means that every value of each motive dimension was related to the average individual level of ex-pectations. In the final step, motive profiles were determined using a hierarchic cluster analysis based on Ward’s method with squared Euclidean distances. Results, discussion and implications The results reveal that motivational processes differ among sports event volunteers, and that volunteers sometimes combine contradictory bundles of motives. In our study, four different volunteer motive profiles were identified and described by their positive levels on the individual motive dimension: the community supporters, the material incentive seekers, the social networkers, and the career and personal growth pursuers. To describe the four identified motive profiles in more detail and to externally validate them, the clusters were analysed in relation to socio-economic, sport-related, and voluntary work characteristics. This motive-based typology of sports event volunteers can provide valuable guidance for event managers in order to create distinctive and designable working conditions and tasks at sporting events that should, in relation to a person-oriented approach, be tailored to a wide range of individ-ual prerequisites. Furthermore, specific recruitment procedures and appropriate communication measures can be defined in order to approach certain groups of potential volunteers more effectively. References Bang, H., & Chelladurai, P. (2009). Development and validation of the volunteer motivations scale for international sporting events (VMS-ISE). International Journal Sport Management and Market-ing, 6, 332-350. Bergmann, L. R., Magnusson, D., & El-Khouri, B. M. (2003). Studying individual development in an interindividual context. Mahwah, NJ: Erlbaum. Dolnicar, S., & Randle, M. (2007). What motivates which volunteers? Psychographic heterogeneity among volunteers in Australia. Voluntas, 18, 135-155. Spiel, C. (1998). Four methodological approaches to the study of stability and change in develop-ment. Methods of Psychological Research Online, 3, 8-22. Stukas, A. A., Worth, K. A., Clary, E. G., & Snyder, M. (2009). The matching of motivations to affordances in the volunteer environment: an index for assessing the impact of multiple matches on volunteer outcomes. Nonprofit and Voluntary Sector Quarterly, 38, 5-28.