scholarly journals Biosignal-Based Attention Monitoring to Support Nuclear Operator Safety-Relevant Tasks

2020 ◽  
Vol 14 ◽  
Author(s):  
Jung Hwan Kim ◽  
Chul Min Kim ◽  
Eun-Soo Jung ◽  
Man-Sung Yim

In the main control room (MCR) of a nuclear power plant (NPP), the quality of an operator's performance can depend on their level of attention to the task. Insufficient operator attention accounted for more than 26% of the total causes of human errors and is the highest category for errors. It is therefore necessary to check whether operators are sufficiently attentive either as supervisors or peers during reactor operation. Recently, digital control technologies have been introduced to the operating environment of an NPP MCR. These upgrades are expected to enhance plant and operator performance. At the same time, because personal computers are used in the advanced MCR, the operators perform more cognitive works than physical work. However, operators may not consciously check fellow operators' attention in this environment indicating potentially higher importance of the role of operator attention. Therefore, remote measurement of an operator's attention in real time would be a useful tool, providing feedback to supervisors. The objective of this study is to investigate the development of quantitative indicators that can identify an operator's attention, to diagnose or detect a lack of operator attention thus preventing potential human errors in advanced MCRs. To establish a robust baseline of operator attention, this study used two of the widely used biosignals: electroencephalography (EEG) and eye movement. We designed an experiment to collect EEG and eye movements of the subjects who were monitoring and diagnosing nuclear operator safety-relevant tasks. There was a statistically significant difference between biosignals with and without appropriate attention. Furthermore, an average classification accuracy of about 90% was obtained by the k-nearest neighbors and support vector machine classifiers with a few EEG and eye movements features. Potential applications of EEG and eye movement measures in monitoring and diagnosis tasks in an NPP MCR are also discussed.

2021 ◽  
Vol 11 (8) ◽  
pp. 990
Author(s):  
Lindsey M. Ward ◽  
Zoi Kapoula

Dyslexic adolescents demonstrate deficits in word decoding, recognition, and oculomotor coordination as compared to healthy controls. Our lab recently showed intrinsic deficits in large saccades and vergence movements with a Remobi device independent from reading. This shed new light on the field of dyslexia, as it has been debated in the literature whether the deficits in eye movements are a cause or consequence of reading difficulty. The present study investigates how these oculomotor problems are compensated for or aggravated by text difficulty. A total of 46 dyslexic and 41 non-dyslexic adolescents’ eye movements were analyzed while reading L’Alouette, a dyslexia screening test, and 35 Kilos D’Espoir, a children’s book with a reading age of 10 years. While reading the more difficult text, dyslexics made more mistakes, read slower, and made more regressive saccades; moreover, they made smaller amplitude saccades with abnormal velocity profiles (e.g., higher peak velocity but lower average velocity) and significantly higher saccade disconjugacy. While reading the simpler text, these differences persisted; however, the difference in saccade disconjugacy, although present, was no longer significant, nor was there a significant difference in the percentage of regressive saccades. We propose that intrinsic eye movement abnormalities in dyslexics such as saccade disconjugacy, abnormal velocity profiles, and cognitively associated regressive saccades can be particularly exacerbated if the reading text relies heavily on word decoding to extract meaning; increased number of regressive saccades are a manifestation of reading difficulty and not a problem of eye movement per se. These interpretations are in line with the motor theory of visual attention and our previous research describing the relationship between binocular motor control, attention, and cognition that exists outside of the field of dyslexia.


Biosensors ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 198
Author(s):  
Xiaoming Wang ◽  
Yineng Xiao ◽  
Fangming Deng ◽  
Yugen Chen ◽  
Hailiang Zhang

To assist patients with restricted mobility to control wheelchair freely, this paper presents an eye-movement-controlled wheelchair prototype based on a flexible hydrogel biosensor and Wavelet Transform-Support Vector Machine (WT-SVM) algorithm. Considering the poor deformability and biocompatibility of rigid metal electrodes, we propose a flexible hydrogel biosensor made of conductive HPC/PVA (Hydroxypropyl cellulose/Polyvinyl alcohol) hydrogel and flexible PDMS (Polydimethylsiloxane) substrate. The proposed biosensor is affixed to the wheelchair user’s forehead to collect electrooculogram (EOG) and strain signals, which are the basis to recognize eye movements. The low Young’s modulus (286 KPa) and exceptional breathability (18 g m−2 h−1 of water vapor transmission rate) of the biosensor ensures a conformal and unobtrusive adhesion between it and the epidermis. To improve the recognition accuracy of eye movements (straight, upward, downward, left, and right), the WT-SVM algorithm is introduced to classify EOG and strain signals according to different features (amplitude, duration, interval). The average recognition accuracy reaches 96.3%, thus the wheelchair can be manipulated precisely.


2017 ◽  
Author(s):  
Chaoguang Wang ◽  
Gino Yu

BACKGROUND All eye movements are related in one way or another to our mental processes with lateral eye movements being associated with the different hemispheres of the brain. Eye movement techniques form the basis of eye movement desensitization and reprocessing therapy, wherein forced eye movements activate neurological pathways to treat the subject. OBJECTIVE The objective of our study was to examine the relationship between players' eye movements and their brain wave activities using a video game. METHODS We used similar eye movement techniques in the form of a video game called Lifeguard that could potentially stimulate different eye movement mode and create a more engaging experience for the user. By designing an experiment, we further explored the differences in electroencephalogram spectral power activity for the alpha, beta, theta, delta, and gamma frequency bands in Lifeguard and Tetris. RESULTS The game based on eye movement technologies resulted in decreased delta power and increased beta power, but significant difference between 2 games was not found. CONCLUSIONS The applied uses of this research could mean that eye movement desensitization and reprocessing can be conducted in a more fun and engaging way through the use of gaming technology.


2017 ◽  
Vol 2 (6) ◽  
pp. 133
Author(s):  
Noor Halilah Buari ◽  
Muhammad Zahir Nur-Zahirah

As a person read, the eyes move to extract information from the printed text. Reading became disturbed when obstructed by the scotoma. The effect of reading and eye movement were investigated between different locations of simulated central vision scotoma. The time to read the text and the eye movements were recorded and tracked among eleven participants. The reading speed showed a significant difference at different locations of central scotoma simulation. The presence of central scotoma affects the quality of reading as the eye moved slowly during reading in order to comprehend the text.


2019 ◽  
Vol 24 (4) ◽  
pp. 297-311
Author(s):  
José David Moreno ◽  
José A. León ◽  
Lorena A. M. Arnal ◽  
Juan Botella

Abstract. We report the results of a meta-analysis of 22 experiments comparing the eye movement data obtained from young ( Mage = 21 years) and old ( Mage = 73 years) readers. The data included six eye movement measures (mean gaze duration, mean fixation duration, total sentence reading time, mean number of fixations, mean number of regressions, and mean length of progressive saccade eye movements). Estimates were obtained of the typified mean difference, d, between the age groups in all six measures. The results showed positive combined effect size estimates in favor of the young adult group (between 0.54 and 3.66 in all measures), although the difference for the mean number of fixations was not significant. Young adults make in a systematic way, shorter gazes, fewer regressions, and shorter saccadic movements during reading than older adults, and they also read faster. The meta-analysis results confirm statistically the most common patterns observed in previous research; therefore, eye movements seem to be a useful tool to measure behavioral changes due to the aging process. Moreover, these results do not allow us to discard either of the two main hypotheses assessed for explaining the observed aging effects, namely neural degenerative problems and the adoption of compensatory strategies.


2020 ◽  
Vol 10 (5) ◽  
pp. 92
Author(s):  
Ramtin Zargari Marandi ◽  
Camilla Ann Fjelsted ◽  
Iris Hrustanovic ◽  
Rikke Dan Olesen ◽  
Parisa Gazerani

The affective dimension of pain contributes to pain perception. Cognitive load may influence pain-related feelings. Eye tracking has proven useful for detecting cognitive load effects objectively by using relevant eye movement characteristics. In this study, we investigated whether eye movement characteristics differ in response to pain-related feelings in the presence of low and high cognitive loads. A set of validated, control, and pain-related sounds were applied to provoke pain-related feelings. Twelve healthy young participants (six females) performed a cognitive task at two load levels, once with the control and once with pain-related sounds in a randomized order. During the tasks, eye movements and task performance were recorded. Afterwards, the participants were asked to fill out questionnaires on their pain perception in response to the applied cognitive loads. Our findings indicate that an increased cognitive load was associated with a decreased saccade peak velocity, saccade frequency, and fixation frequency, as well as an increased fixation duration and pupil dilation range. Among the oculometrics, pain-related feelings were reflected only in the pupillary responses to a low cognitive load. The performance and perceived cognitive load decreased and increased, respectively, with the task load level and were not influenced by the pain-related sounds. Pain-related feelings were lower when performing the task compared with when no task was being performed in an independent group of participants. This might be due to the cognitive engagement during the task. This study demonstrated that cognitive processing could moderate the feelings associated with pain perception.


2009 ◽  
Vol 101 (2) ◽  
pp. 934-947 ◽  
Author(s):  
Masafumi Ohki ◽  
Hiromasa Kitazawa ◽  
Takahito Hiramatsu ◽  
Kimitake Kaga ◽  
Taiko Kitamura ◽  
...  

The anatomical connection between the frontal eye field and the cerebellar hemispheric lobule VII (H-VII) suggests a potential role of the hemisphere in voluntary eye movement control. To reveal the involvement of the hemisphere in smooth pursuit and saccade control, we made a unilateral lesion around H-VII and examined its effects in three Macaca fuscata that were trained to pursue visually a small target. To the step (3°)-ramp (5–20°/s) target motion, the monkeys usually showed an initial pursuit eye movement at a latency of 80–140 ms and a small catch-up saccade at 140–220 ms that was followed by a postsaccadic pursuit eye movement that roughly matched the ramp target velocity. After unilateral cerebellar hemispheric lesioning, the initial pursuit eye movements were impaired, and the velocities of the postsaccadic pursuit eye movements decreased. The onsets of 5° visually guided saccades to the stationary target were delayed, and their amplitudes showed a tendency of increased trial-to-trial variability but never became hypo- or hypermetric. Similar tendencies were observed in the onsets and amplitudes of catch-up saccades. The adaptation of open-loop smooth pursuit velocity, tested by a step increase in target velocity for a brief period, was impaired. These lesion effects were recognized in all directions, particularly in the ipsiversive direction. A recovery was observed at 4 wk postlesion for some of these lesion effects. These results suggest that the cerebellar hemispheric region around lobule VII is involved in the control of smooth pursuit and saccadic eye movements.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Talora L. Martin ◽  
Jordan Murray ◽  
Kiran Garg ◽  
Charles Gallagher ◽  
Aasef G. Shaikh ◽  
...  

AbstractWe evaluated the effects of strabismus repair on fixational eye movements (FEMs) and stereopsis recovery in patients with fusion maldevelopment nystagmus (FMN) and patients without nystagmus. Twenty-one patients with strabismus, twelve with FMN and nine without nystagmus, were tested before and after strabismus repair. Eye-movements were recorded during a gaze-holding task under monocular viewing conditions. Fast (fixational saccades and quick phases of nystagmus) and slow (inter-saccadic drifts and slow phases of nystagmus) FEMs and bivariate contour ellipse area (BCEA) were analyzed in the viewing and non-viewing eye. Strabismus repair improved the angle of strabismus in subjects with and without FMN, however patients without nystagmus were more likely to have improvement in stereoacuity. The fixational saccade amplitudes and intersaccadic drift velocities in both eyes decreased after strabismus repair in subjects without nystagmus. The slow phase velocities were higher in patients with FMN compared to inter-saccadic drifts in patients without nystagmus. There was no change in the BCEA after surgery in either group. In patients without nystagmus, the improvement of the binocular function (stereopsis), as well as decreased fixational saccade amplitude and intersaccadic drift velocity, could be due, at least partially, to central adaptive mechanisms rendered possible by surgical realignment of the eyes. The absence of improvement in patients with FMN post strabismus repair likely suggests the lack of such adaptive mechanisms in patients with early onset infantile strabismus. Assessment of fixation eye movement characteristics can be a useful tool to predict functional improvement post strabismus repair.


1980 ◽  
Vol 50 (2) ◽  
pp. 631-636
Author(s):  
Evans Mandes

Post-exposural eye movements were studied in 32 adults and 24 7-yr.-old children. Stimuli were binary figures exposed tachistoscopically in both visual fields simultaneously. The data showed significant correlations between direction of eye movement and locus of recognition for both children and adults. No significant differences were found in frequencies of eye movements of children and adults. The data are interpreted in terms of the facilitative effects of post-exposural eye movements upon perception for both groups.


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