8,789 research outputs found
Methodology to assess safety effects of future Intelligent Transport Systems on railway level crossings
There is consistent evidence showing that driver behaviour contributes to crashes and near miss incidents at railway level crossings (RLXs). The development of emerging Vehicle-to-Vehicle and Vehicle-to-Infrastructure technologies is a highly promising approach to improve RLX safety. To date, research has not evaluated comprehensively the potential effects of such technologies on driving behaviour at RLXs. This paper presents an on-going research programme assessing the impacts of such new technologies on human factors and drivers’ situational awareness at RLX. Additionally, requirements for the design of such promising technologies and ways to display safety information to drivers were systematically reviewed. Finally, a methodology which comprehensively assesses the effects of in-vehicle and road-based interventions warning the driver of incoming trains at RLXs is discussed, with a focus on both benefits and potential negative behavioural adaptations. The methodology is designed for implementation in a driving simulator and covers compliance, control of the vehicle, distraction, mental workload and drivers’ acceptance. This study has the potential to provide a broad understanding of the effects of deploying new in-vehicle and road-based technologies at RLXs and hence inform policy makers on safety improvements planning for RLX
Constructing sonified haptic line graphs for the blind student: first steps
Line graphs stand as an established information visualisation and analysis technique taught at various levels of difficulty according to standard Mathematics curricula. It has been argued that blind individuals cannot use line graphs as a visualisation and analytic tool because they currently primarily exist in the visual medium. The research described in this paper aims at making line graphs accessible to blind students through auditory and haptic media. We describe (1) our design space for representing line graphs, (2) the technology we use to develop our prototypes and (3) the insights from our preliminary work
Aerospace Medicine and Biology: A continuing bibliography with indexes (supplement 314)
This bibliography lists 139 reports, articles, and other documents introduced into the NASA scientific and technical information system in August, 1988
Augmenting Sensorimotor Control Using “Goal-Aware” Vibrotactile Stimulation during Reaching and Manipulation Behaviors
We describe two sets of experiments that examine the ability of vibrotactile encoding of simple position error and combined object states (calculated from an optimal controller) to enhance performance of reaching and manipulation tasks in healthy human adults. The goal of the first experiment (tracking) was to follow a moving target with a cursor on a computer screen. Visual and/or vibrotactile cues were provided in this experiment, and vibrotactile feedback was redundant with visual feedback in that it did not encode any information above and beyond what was already available via vision. After only 10 minutes of practice using vibrotactile feedback to guide performance, subjects tracked the moving target with response latency and movement accuracy values approaching those observed under visually guided reaching. Unlike previous reports on multisensory enhancement, combining vibrotactile and visual feedback of performance errors conferred neither positive nor negative effects on task performance. In the second experiment (balancing), vibrotactile feedback encoded a corrective motor command as a linear combination of object states (derived from a linear-quadratic regulator implementing a trade-off between kinematic and energetic performance) to teach subjects how to balance a simulated inverted pendulum. Here, the tactile feedback signal differed from visual feedback in that it provided information that was not readily available from visual feedback alone. Immediately after applying this novel “goal-aware” vibrotactile feedback, time to failure was improved by a factor of three. Additionally, the effect of vibrotactile training persisted after the feedback was removed. These results suggest that vibrotactile encoding of appropriate combinations of state information may be an effective form of augmented sensory feedback that can be applied, among other purposes, to compensate for lost or compromised proprioception as commonly observed, for example, in stroke survivors
Swayed by sound: sonic guidance as a neurorehabilitation strategy in the cerebellar ataxias
Cerebellar disease leads to problems in controlling movement. The most common
difficulties are dysmetria and instability when standing.
Recent understanding of cerebellar function has expanded to include non -motor
aspects such as emotional, cognitive and sensory processing. Deficits in the
acquisition and processing of sensory information are one explanation for the
movement problems observed in cerebellar ataxia. Sensory deficits result in an
inability to make predictions about future events; a primary function of the
cerebellum. A question therefore, is whether augmenting or replacing sensory
information can improve motor performance in cerebellar disease. This question is
tested in this thesis by augmenting sensory information through the provision of an
auditory movement guide.A variable described in motor control theory (tau) was used to develop auditory
guides that were continuous and dynamic. A reaching experiment using healthy
individuals showed that the timing of peak velocity, audiomotor coordination
accuracy, and velocity of approach, could be altered in line with the movement
parameters embedded in the auditory guides. The thesis then investigated the use of
these sonic guides in a clinical population with cerebellar disease. Performance on
neurorehabilitation exercises for balance control was tested in twenty people with
cerebellar atrophy, with and without auditory guides. Results suggested that
continuous, predictive, dynamic auditory guidance is an effective way of improving
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movement smoothness in ataxia (as measured by jerk). In addition, generating and
swaying with imaginary auditory guides was also found to increase movement
smoothness in cerebellar disease.Following the tests of instantaneous effects, the thesis then investigated the longterm consequences on motor behaviour of following a two -month exercise with
auditory guide programme. Seven people with cerebellar atrophy were assessed pre - and post -intervention using two measures, weight -shifting and walking. The results
of the weight -shifting test indicated that the sonic -guide exercise programme does
not initiate long -term changes in motor behaviour. Whilst there were minor,
improvements in walking, because of the weight -shifting results, these could not be
attributed to the sonic guides. This finding confirms the difficulties of motor
rehabilitation in people with cerebellar disease.This thesis contributes original findings to the field of neurorehabilitation by first
showing that on -going and predictive stimuli are an appropriate tool for improving
motor behaviour. In addition, the thesis is the first of its kind to apply externally
presented guides that convey continuous meaningful information within a clinical
population. Finally, findings show that sensory augmentation using the auditory
domain is an effective way of improving motor coordination in some forms of
cerebellar disease
The Impact of Age and Physical Activity Level on Manual Aiming Performance
Older adults traditionally adapt their discrete aiming movements, thereby travelling a larger proportion of the movement under closed-loop control. As the beneficial impact of a physically active lifestyle in old age has been described for several aspects of motor control, we compared the aiming performance of young controls to active and sedentary older adults. To additionally determine the contribution of visual feedback, aiming movements were executed with and without saccades. Results showed only sedentary older adults adopted the typical movement changes, highlighting the impact of a physically active lifestyle on manual aiming in old age. In an attempt to reveal the mechanism underlying the movement changes, evidence for an age-related decline in force control was found, which in turn resulted in an adapted aiming strategy. Finally, prohibiting saccades did not affect older adults’ performance to a greater extent, suggesting they do not rely more on visual feedback than young controls.
Keywords: aging, physical activity, manual aiming, eye movement
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