scholarly journals Effect of environmental factors on how older pedestrians detect an upcoming step

2016 ◽  
Vol 50 (3) ◽  
pp. 405-415 ◽  
Author(s):  
T-J Cheng ◽  
B Yang ◽  
C Holloway ◽  
N Tyler
Keyword(s):  
Visual Information ◽  
Fixation Duration ◽  
Light Level ◽  
Eye Tracker ◽  
Detection Distance ◽  
Processing Efficiency ◽  
Trial Time ◽  
Light Levels ◽  
Gaze Behaviour ◽  
The Impact

The relationships between environmental features and older people's ability to safely move around a complex pedestrian environment are, as yet, poorly understood. Specifically, the impact of light levels on trip hazard detection during walking has received relatively little attention. This study investigates the effect of illuminance on people's ability to detect steps of different heights in a laboratory-based controlled environment. Sixteen young and 15 older participants walked along a 13.2 m walkway towards an either ascending or descending step at 200 lux or 4 lux light levels. Trial time, gaze behaviour and distance at which the step was first visually fixated (detection distance) were measured using an eye-tracker. It was found that both the trial time and detection distance of older participants were affected by light level whereas the fixation number and fixation duration of young participants were affected by step-height. Shorter detection distance, greater number of fixations and longer fixation duration were found among older participants as opposed to young participants. The results suggest that the processing efficiency for visual information on an upcoming step is slower among older people than among young people. This implies that the vulnerability of older pedestrians maybe be reduced if better lighting or a simplified visual environment is provided.

Study on the Impact of Light on Human Physiology and Electroencephalogram

2016 ◽  
Vol 28 ◽  
pp. 36-43
Author(s):  
John William Carey Medithe ◽  
Usha Rani Nelakuditi
Keyword(s):  
Brain Activity ◽  
Bright Light ◽  
Light Level ◽  
Brain Disorder ◽  
Lighting Condition ◽  
Subjective Analysis ◽  
Physiological Variables ◽  
Light Levels ◽  
Low Luminance ◽  
The Impact

The influence of light on Electroencephalogram seems to be more critical, when physician depends on its readings to diagnose subject brain disorder according to its level. Although, bright light brings various changes in human physiological variables. But, Neurophysiological changes for specific light level still remain unclear. Thereby, in the present study, the response of brain electrical activity towards various light levels has been classified and verified. The reasons for alteration in different physiological variables due to bright light which results change in the state of electroencephalographic recordings has been reviewed. Additionally, the effects of bright light towards Ocular artifacts are also put forward. A novel hypothesis has been made using subjective analysis and experimental analysis in low luminance or darkness. It is observed that a poor lighting condition affects both behavioral task and brain activity.

scholarly journals Study on Driver Gaze Characteristics in Sight Distance Limited Section of Mountain Highway Based on Visual Information

2022 ◽  
Vol 2022 ◽  
pp. 1-8
Author(s):  
Yuzhou Tang ◽  
Xiaodang Peng ◽  
Shiyong Xu ◽  
Mingju Bai ◽  
Lifang Lin ◽  
...  
Keyword(s):  
Visual Information ◽  
Fixation Duration ◽  
Rate Theory ◽  
Eye Tracker ◽  
Gaze Behavior ◽  
Distribution Law ◽  
Change Rate ◽  
The Gaze ◽  
Sight Distance ◽  
Distance Change

In order to study the gaze behavior characteristics of drivers in mountainous road sections with limited sight distance, the real vehicle test is carried out by using Smart Eye Pro 5.7 noninvasive eye tracker. Combined with the sight distance change rate theory, 6 typical test representative mountainous sections are selected to study the gaze distribution law and gaze duration of drivers in different mountainous sections. The research shows that when the driver drives on the test section with the most unfavorable sight distance of 44 m, 50 m, and 56 m, the fixation characteristics of “from far to near” are significant, and the long fixation duration accounts for a large proportion of the driver. When the driver drives on the section with the most unfavorable sight distance of more than 70 m, i.e., the sight distance change rate of less than 1.33, the fixation characteristics of “from far to near” disappear. The driver’s fixation stability increases, the fixation freedom increases, and the proportion of medium and long fixation duration decreases. The data analysis provides a theoretical basis for drivers to pass safely in mountainous sections.

Change of color appearance due to extremely high light level: corresponding colors under 100 and 3000 cd/m2

2019 ◽  
Vol 2019 (1) ◽  
pp. 320-325 ◽  
Author(s):  
Wenyu Bao ◽  
Minchen Wei
Keyword(s):  
Light Level ◽  
Limited Range ◽  
High Light ◽  
Color Preference ◽  
Color Appearance ◽  
Appearance Model ◽  
Color Matching ◽  
Light Levels ◽  
Appearance Models ◽  
Psychophysical Study

Great efforts have been made to develop color appearance models to predict color appearance of stimuli under various viewing conditions. CIECAM02, the most widely used color appearance model, and many other color appearance models were all developed based on corresponding color datasets, including LUTCHI data. Though the effect of adapting light level on color appearance, which is known as "Hunt Effect", is well known, most of the corresponding color datasets were collected within a limited range of light levels (i.e., below 700 cd/m2), which was much lower than that under daylight. A recent study investigating color preference of an artwork under various light levels from 20 to 15000 lx suggested that the existing color appearance models may not accurately characterize the color appearance of stimuli under extremely high light levels, based on the assumption that the same preference judgements were due to the same color appearance. This article reports a psychophysical study, which was designed to directly collect corresponding colors under two light levels— 100 and 3000 cd/m2 (i.e., ≈ 314 and 9420 lx). Human observers completed haploscopic color matching for four color stimuli (i.e., red, green, blue, and yellow) under the two light levels at 2700 or 6500 K. Though the Hunt Effect was supported by the results, CIECAM02 was found to have large errors under the extremely high light levels, especially when the CCT was low.

Eye movements in sports research and practice: Immersive technologies as optimal environments for the study of gaze behaviour

2020 ◽  
Author(s):  
David Harris ◽  
Mark Wilson ◽  
Tim Holmes ◽  
Toby de Burgh ◽  
Samuel James Vine
Keyword(s):  
Virtual Reality ◽  
Eye Movements ◽  
Eye Tracking ◽  
Visual Information ◽  
Successful Performance ◽  
Experimental Control ◽  
Research And Practice ◽  
Gaze Behaviour ◽  
Immersive Technologies

Head-mounted eye tracking has been fundamental for developing an understanding of sporting expertise, as the way in which performers sample visual information from the environment is a major determinant of successful performance. There is, however, a long running tension between the desire to study realistic, in-situ gaze behaviour and the difficulties of acquiring accurate ocular measurements in dynamic and fast-moving sporting tasks. Here, we describe how immersive technologies, such as virtual reality, offer an increasingly compelling approach for conducting eye movement research in sport. The possibility of studying gaze behaviour in representative and realistic environments, but with high levels of experimental control, could enable significant strides forward for eye tracking in sport and improve understanding of how eye movements underpin sporting skills. By providing a rationale for virtual reality as an optimal environment for eye tracking research, as well as outlining practical considerations related to hardware, software and data analysis, we hope to guide researchers and practitioners in the use of this approach.

scholarly journals The impact of predictability on dual-task performance and implications for resource-sharing accounts

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Laura Broeker ◽  
Harald Ewolds ◽  
Rita F. de Oliveira ◽  
Stefan Künzell ◽  
Markus Raab
Keyword(s):  
Resource Allocation ◽  
Task Performance ◽  
Dual Task ◽  
Resource Sharing ◽  
Visual Information ◽  
Allocation Policy ◽  
Capacity Sharing ◽  
Dual Task Performance ◽  
Sound Sequence ◽  
The Impact

AbstractThe aim of this study was to examine the impact of predictability on dual-task performance by systematically manipulating predictability in either one of two tasks, as well as between tasks. According to capacity-sharing accounts of multitasking, assuming a general pool of resources two tasks can draw upon, predictability should reduce the need for resources and allow more resources to be used by the other task. However, it is currently not well understood what drives resource-allocation policy in dual tasks and which resource allocation policies participants pursue. We used a continuous tracking task together with an audiomotor task and manipulated advance visual information about the tracking path in the first experiment and a sound sequence in the second experiments (2a/b). Results show that performance predominantly improved in the predictable task but not in the unpredictable task, suggesting that participants did not invest more resources into the unpredictable task. One possible explanation was that the re-investment of resources into another task requires some relationship between the tasks. Therefore, in the third experiment, we covaried the two tasks by having sounds 250 ms before turning points in the tracking curve. This enabled participants to improve performance in both tasks, suggesting that resources were shared better between tasks.

scholarly journals Interphotoreceptor coupling: an evolutionary perspective

2021 ◽  
Author(s):  
Lorenzo Cangiano ◽  
Sabrina Asteriti
Keyword(s):  
Visual Information ◽  
Signal To Noise Ratio ◽  
Electrical Coupling ◽  
Physiological Role ◽  
Cellular Processes ◽  
Contact Points ◽  
Highly Sensitive ◽  
The Many ◽  
The Impact

AbstractIn the vertebrate retina, signals generated by cones of different spectral preference and by highly sensitive rod photoreceptors interact at various levels to extract salient visual information. The first opportunity for such interaction is offered by electrical coupling of the photoreceptors themselves, which is mediated by gap junctions located at the contact points of specialised cellular processes: synaptic terminals, telodendria and radial fins. Here, we examine the evolutionary pressures for and against interphotoreceptor coupling, which are likely to have shaped how coupling is deployed in different species. The impact of coupling on signal to noise ratio, spatial acuity, contrast sensitivity, absolute and increment threshold, retinal signal flow and colour discrimination is discussed while emphasising available data from a variety of vertebrate models spanning from lampreys to primates. We highlight the many gaps in our knowledge, persisting discrepancies in the literature, as well as some major unanswered questions on the actual extent and physiological role of cone-cone, rod-cone and rod-rod communication. Lastly, we point toward limited but intriguing evidence suggestive of the ancestral form of coupling among ciliary photoreceptors.

scholarly journals The impact of translation modality on user experience: an eye-tracking study of the Microsoft Word user interface

2021 ◽  
Author(s):  
Ana Guerberof Arenas ◽  
Joss Moorkens ◽  
Sharon O’Brien
Keyword(s):  
User Interface ◽  
Eye Tracking ◽  
Cognitive Load ◽  
Task Completion ◽  
Eye Tracker ◽  
Software Products ◽  
Microsoft Word ◽  
Set Up ◽  
The Impact ◽  
The Given

AbstractThis paper presents results of the effect of different translation modalities on users when working with the Microsoft Word user interface. An experimental study was set up with 84 Japanese, German, Spanish, and English native speakers working with Microsoft Word in three modalities: the published translated version, a machine translated (MT) version (with unedited MT strings incorporated into the MS Word interface) and the published English version. An eye-tracker measured the cognitive load and usability according to the ISO/TR 16982 guidelines: i.e., effectiveness, efficiency, and satisfaction followed by retrospective think-aloud protocol. The results show that the users’ effectiveness (number of tasks completed) does not significantly differ due to the translation modality. However, their efficiency (time for task completion) and self-reported satisfaction are significantly higher when working with the released product as opposed to the unedited MT version, especially when participants are less experienced. The eye-tracking results show that users experience a higher cognitive load when working with MT and with the human-translated versions as opposed to the English original. The results suggest that language and translation modality play a significant role in the usability of software products whether users complete the given tasks or not and even if they are unaware that MT was used to translate the interface.

scholarly journals Thioredoxin-dependent control balances the metabolic activities of tetrapyrrole biosynthesis

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Daniel Wittmann ◽  
Neha Sinha ◽  
Bernhard Grimm
Keyword(s):  
Environmental Changes ◽  
Nuclear Gene ◽  
Tetrapyrrole Biosynthesis ◽  
Nuclear Gene Expression ◽  
Light Levels ◽  
Organ Specific ◽  
Intracellular Compartments ◽  
The Face ◽  
Metabolic Activities ◽  
The Impact

AbstractPlastids are specialized organelles found in plants, which are endowed with their own genomes, and differ in many respects from the intracellular compartments of organisms belonging to other kingdoms of life. They differentiate into diverse, plant organ-specific variants, and are perhaps the most versatile organelles known. Chloroplasts are the green plastids in the leaves and stems of plants, whose primary function is photosynthesis. In response to environmental changes, chloroplasts use several mechanisms to coordinate their photosynthetic activities with nuclear gene expression and other metabolic pathways. Here, we focus on a redox-based regulatory network composed of thioredoxins (TRX) and TRX-like proteins. Among multiple redox-controlled metabolic activities in chloroplasts, tetrapyrrole biosynthesis is particularly rich in TRX-dependent enzymes. This review summarizes the effects of plastid-localized reductants on several enzymes of this pathway, which have been shown to undergo dithiol-disulfide transitions. We describe the impact of TRX-dependent control on the activity, stability and interactions of these enzymes, and assess its contribution to the provision of adequate supplies of metabolic intermediates in the face of diurnal and more rapid and transient changes in light levels and other environmental factors.

Light or presence of host trees: which is more important for the strangler fig?

1999 ◽  
Vol 15 (5) ◽  
pp. 589-602 ◽  
Author(s):  
Vidya R. Athreya
Keyword(s):  
Host Species ◽  
National Park ◽  
Canopy Cover ◽  
Light Level ◽  
Southern India ◽  
Evergreen Forest ◽  
Primary Forest ◽  
Light Levels ◽  
Host Trees ◽  
Main Host

Strangler fig density varied considerably in the evergreen forest of Karian Shola National Park, southern India, with 11 individuals ha−1 in an open trail area and 5.6 individuals ha−1 within the primary forest area. The index of light level was assessed by estimating the percentage of upper canopy cover along the longitudinal centre of ten, 500-m × 20-m plots in each of the two areas of the evergreen forest. However, the increase in strangler fig density was not correlated to light levels but was significantly correlated to the numbers of their main host species in the two areas. In Karian Shola National Park, strangler figs occurred predominantly on a few host species with 20 and 50% of strangler figs growing on Vitex altissima, Diospyros bourdilloni and Eugenia/Syzygium spp. in the primary forest and trail areas respectively. Both young and established strangler figs were recorded mainly on larger individuals of their host trees indicating that older host trees are likely to be more suitable for the germination and establishment of strangler figs. The reason for the above could be the higher incidence of humus-filled and decaying regions in the older host trees which would provide an assured supply of nutrients for the establishing strangler fig.

scholarly journals Survey of Hearing Aid Conditions for Hearing Impaired Persons While Driving

2020 ◽  
pp. 132-136
Author(s):  
Hiroshi Ikeda ◽  
Shigeyuki Minami
Keyword(s):  
Hearing Loss ◽  
Hearing Aids ◽  
Visual Information ◽  
Hearing Aid ◽  
Hearing Impaired ◽  
Safe Driving ◽  
Actual Usage ◽  
Hearing Ability ◽  
Acquired Hearing Loss ◽  
The Impact

Hearing impaired persons are required to drive with hearing aids to supplement their hearing ability, however, there has not been sufficient discussion regarding the impact of the use of a hearing aid on driving a vehicle. In order to investigate the actual usage and driving conditions of using hearing aids while driving a vehicle, this paper uses a questionnaire to survey (1) how easy it is to drive when wearing hearing aids, and (2) how often hearing aids are not worn while driving. Concerning the ease of driving when wearing a hearing aid, it was suggested that people with congenital hearing loss were more likely to rely on visual information, and those with acquired hearing loss continue to use their experience of hearing. When the level of disability is high, it is difficult to drive when using the hearing aid, and when the disability level is low, it is easier to drive. Regarding the frequency of driving without wearing hearing aids, about 60 % of respondents had such an experience. Those who often drive without hearing aids had experienced headaches due to noise from wearing hearing aids compared to those who wear hearing aids at all times. Hearing aids are necessary assistive devices for hearing impaired persons to obtain hearing information, and to provide a safe driving environment. Therefore, this paper addresses issues to maintain a comfortable driving environment while wearing a hearing aid.

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