On the use of low-cost computer peripherals for the assessment of motor dysfunction in Parkinson’s disease – Quantification of bradykinesia using target tracking tasks

The potential of computer games peripherals to measure the motor dysfunction in Parkinson’s diseases is assessed. Of particular interest is the quantification of bradykinesia. Previous studies used modified or custom haptic interfaces, here an unmodified force feedback joystick and steering wheel are used with a laptop. During testing an on screen cursor moves in response to movements of the peripheral, the user has to track a continuously moving target (pursuit tracking), or move to a predetermined target (step tracking). All tasks use movement in the horizontal axis, allowing use of joystick or steering wheel. Two pursuit tracking tasks are evaluated, pseudo random movement, and a swept frequency task. Two step tracking tasks are evaluated, movement between two or between two of five fixed targets. Thirteen patients and five controls took part on a weekly basis. Patients were assessed for bradykinesia at each session using standard clinical measures. A range of quantitative measures was developed to allow comparison between and within patients and controls using ANOVA. Both peripherals are capable of discriminating between controls and patients, and between patients with different levels of bradykinesia. Recommendations for test procedures and peripherals are given

Is movement better? Comparing sedentary and motion-based game controls for older adults

Providing cognitive and physical stimulation for older adults is critical for their well-being. Video games offer the opportunity of engaging seniors, and research has shown a variety of positive effects of motion-based video games for older adults. However, little is known about the suitability of motion-based game controls for older adults and how their use is affected by age-related changes. In this paper, we present a study evaluating sedentary and motion-based game controls with a focus on differences between younger and older adults. Our results show that older adults can apply motion-based game controls efficiently, and that they enjoy motion-based interaction. We present design implications based on our study, and demonstrate how our findings can be applied both to motion-based game design and to general interaction design for older adults. Copyright held by authors

Surrogate in-vehicle information systems and driver behaviour: Effects of visual and cognitive load in simulated rural driving

The underlying aim of HASTE, an EU FP5 project, is the development of a valid, cost-effective and reliable assessment protocol to evaluate the potential distraction of an in-vehicle information system on driving performance. As part of this development, the current study was performed to examine the systematic relationship between primary and secondary task complexity for a specific task modality in a particular driving environment. Two fundamentally distinct secondary tasks (or surrogate in-vehicle information systems, sIVIS) were developed: a visual search task, designed such that it only required visual processing/demand and an auditory continuous memory task, intended to cognitively load drivers without any visual stimulus. A high fidelity, fixed-base driving simulator was used to test 48 participants on a car following task. Virtual traffic scenarios varied in driving demand. Drivers compensated for both types of sIVIS by reducing their speed (this result was more prominent during interaction with the visual task). However, they seemed incapable of fully prioritising the primary driving task over either the visual or cognitive secondary tasks as an increase in sIVIS demand was associated with a reduction in driving performance: drivers showed reduced anticipation of braking requirements and shorter time-to-collision. These results are of potential interest to designers of in-vehicle systems

Issues arising from the HASTE experiments

[FIRST PARAGRAPH] The HASTE project work discussed in the foregoing papers can be depicted as being aimed at answering two questions: “Does greater secondary task load from an In-Vehicle Information System (IVIS) lead to an identifiably worse performance in the primary task of driving?” and “How much distraction is too much?”. There is, of course, a huge amount of literature examining the effect of distraction on driving. Some of this concerns visual distraction (e.g. Holohan, Culler & Wilcox, 1978; Dingus, Antin, Hulse & Wierwille, 1989; Wierwille & Tijerina, 1996; Wallace, 2003), while other parts cover distraction from cognitive (auditory) tasks such as mobile phone use (e.g. Stevens & Paulo, 1999; Svenson & Patten, 2003). But, in spite of this large background of research, it can be argued that the HASTE work was pioneering in the sense that it attempted to differentiate between the effects of visual and cognitive distraction and at the same time it attempted to carefully control the “dose” of distraction administered at any one time. These dose-response studies were carried out in three common but quite different experimental settings, a laboratory set-up, advanced driving simulators, and in instrumented vehicles in the field. The project also examined the reliability of the evaluation, with for example six replications of the rural road studies across a variety of driving simulators in five different countries

The impact of central government steering and local network dynamics on the performance of mandated service delivery networks: the case of the Primary Health Care networks in Flanders

This paper focuses on the impact of central – local relations on the performance of local service delivery networks set up by central government. Analyzing network literature leaves us with some questions about the impact of coordination strategies of central government as a possible determinant of network-level effectiveness for this type of network and the possible interaction between central government coordination (as part of the network context) and internal network dynamics and the combined effects hereof on the effectiveness of mandated service delivery networks in particular. Our analysis shows that both levels are important to explain the outcomes of the Primary Health Care networks in Flanders. Our study also leads to some important observations about the meaning of ‘central government coordination’ in this context

Target Acquisition in Multiscale Electronic Worlds

Since the advent of graphical user interfaces, electronic information has grown exponentially, whereas the size of screen displays has stayed almost the same. Multiscale interfaces were designed to address this mismatch, allowing users to adjust the scale at which they interact with information objects. Although the technology has progressed quickly, the theory has lagged behind. Multiscale interfaces pose a stimulating theoretical challenge, reformulating the classic target-acquisition problem from the physical world into an infinitely rescalable electronic world. We address this challenge by extending Fitts’ original pointing paradigm: we introduce the scale variable, thus defining a multiscale pointing paradigm. This article reports on our theoretical and empirical results. We show that target-acquisition performance in a zooming interface must obey Fitts’ law, and more specifically, that target-acquisition time must be proportional to the index of difficulty. Moreover, we complement Fitts’ law by accounting for the effect of view size on pointing performance, showing that performance bandwidth is proportional to view size, up to a ceiling effect. The first empirical study shows that Fitts’ law does apply to a zoomable interface for indices of difficulty up to and beyond 30 bits, whereas classical Fitts’ law studies have been confined in the 2-10 bit range. The second study demonstrates a strong interaction between view size and task difficulty for multiscale pointing, and shows a surprisingly low ceiling. We conclude with implications of these findings for the design of multiscale user interfaces

Description and simulation of an integrated power and attitude control system concept for space-vehicle application

An Integrated Power and Attitude Control System (IPACS) concept with potential application to a broad class of space missions is discussed. A description is given of the basic concept of combining the onboard energy storage and attitude control functions by storing energy in spinning flywheels which are used to provide control torques. A shuttle-launched Research and Applications Module (RAM) A303B solar-observatory mission having stringent pointing requirements (1.0 arc second) is selected to investigate possible interactions between energy storage and attitude control. A simulation of this spacecraft involving actual laboratory-model control-system hardware is presented. Simulation results are discussed which indicate that the IPACS concept, even in a failure-mode configuration, can readily meet the RAM A303B pointing requirements