15 research outputs found
Towards continuous and real-time attention monitoring at work: reaction time versus brain response
Continuous and objective measurement of the user attention state still represents a major challenge in the ergonomics research. Recently available wearable electroencephalography (EEG) opens new opportunities for objective and continuous evaluation of operators' attention, which may provide a new paradigm in ergonomics. In this study, wearable EEG was recorded during simulated assembly operation, with the aim to analyse P300 event-related potential component, which provides reliable information on attention processing. In parallel, reaction times (RTs) were recorded and the correlation between these two attention-related modalities was investigated. Negative correlation between P300 amplitudes and RTs has been observed on the group level (p lt .001). However, on the individual level, the obtained correlations were not consistent. As a result, we propose the P300 amplitude for accurate attention monitoring in ergonomics research. On the other hand, no significant correlation between RTs and P300 latency was found on group, neither on individual level. Practitioner Summary: Ergonomic studies of assembly operations mainly investigated physical aspects, while mental states of the assemblers were not sufficiently addressed. Presented study aims at attention tracking, using realistic workplace replica. It is shown that drops in attention could be successfully traced only by direct brainwave observation, using wireless electroencephalographic measurements.This is the peer-reviewed version of the article: Mijović, P.; Ković, V.; De Vos, M.; Macuzić, I.; Todorović, P.; Jeremić, B.; Gligorijević, I. Towards Continuous and Real-Time Attention Monitoring at Work: Reaction Time versus Brain Response. Ergonomics 2017, 60 (2), 241–254. [https://doi.org/10.1080/00140139.2016.1142121
The effect of colour on reading performance in children, measured by a sensor hub: From the perspective of gender
In recent decades reported findings regarding gender differences in reading achievement, cognitive abilities and maturation process in boys and girls are conflicting. As reading is one of the most important processes in the maturation of an individual, the aim of the study was to better understand gender differences between primary school students. The study evaluates differences in Heart Rate Variability (HRV), Electroencephalography (EEG), Electrodermal Activities (EDA) and eye movement of participants during the reading task. Taking into account that colour may affect reading skills, in that it affects the emotional and physiological state of the body, the research attempts to provide a better understanding of gender differences in reading through examining the effect of colour, as applied to reading content. The physiological responses of 50 children (25 boys and 25 girls) to 12 different background and overlay colours of reading content were measured and summarised during the reading process. Our findings show that boys have shorter reading duration scores and a longer Saccade Count, Saccade Duration Total, and Saccade Duration Average when reading on a coloured background, especially purple, which could be caused by their motivation and by the type of reading task. Also, the boys had higher values for the Delta band and the Whole Range of EEG measurements in comparison to the girls when reading on coloured backgrounds, which could reflect the faster maturation of the girls. Regarding EDA measurements we did not find systematic differences between groups either on white or on coloured/overlay background. We found the most significant differences arose in the HRV parameters, namely (SDNN (ms), STD HR (beats/min), RMSSD (ms), NN50 (beats), pNN50 (%), CVRR) when children read the text on coloured/overlay backgrounds, where the girls showed systematically higher values on HRV measurements in comparison to the boys, mostly with yellow, red, and orange overlay colours
Sexual dimorphism of medium-sized neurons with spines in human nucleus accumbens
The nucleus accumbens is a limbic nucleus, representing part of the striatum body, and together with the caudate nucleus and putamen, it lies on the septum. The aim of this study was to examine morphological sexual dimorphism in spine density and also to undertake an immunohistochemical study of expression for estrogen and progesterone receptors in the medium-sized neurons in the nucleus accumbens. The research was conducted on twenty human brains of persons of both sexes, between the age of 20-75 years. The Golgi method was applied to determine the types and subtypes of neurons, morphologies of soma, dendrites and axons, as well as the relations between the cells and glial elements. The following were quantitatively examined: the maximum diameter of the neurons, the minimal diameter of the neurons, and the total length of the dendrites. The expression of receptors for estrogen and progesterone, their distribution and intensity were defined immunohistochemically. The parameters of the bodies of neurons in the shell and core of the nucleus accumbens were studied in both men and women. No statistically significant differences were found. Examination of the spine density showed statistical significance in terms of a higher density of spines in women. Immunohistochemically, in the female brain estrogen expression is diffusely spread in a large number of neurons; it is extra nuclear, of granular appearance and high intensity. In the male brain, expression of estrogen is visible and distributed over about one half of different types of neurons; it is extra nuclear, of granular appearance, mostly of middle and low staining intensity. Expression of progesterone in the female brain was very discreet and on a very small number of neurons; it was extra nuclear and with a weak staining intensity. Expression of progesterone in the male brain was distributed on a small number of neurons. It had a granular appearance, it was extra nuclear, with a very low staining intensity. Our results show differences in the morphology as well as expression of receptors for estrogen and progesterone on medium-sized neurons with spines in the nucleus accumbens of men and women
Towards creation of implicit HCI model for prediction and prevention of operators’ error
This paper describes development of a new generation of the interactive industrial workplace, through introduction of a novel implicit Human Computer Interaction (HCI) model. Proposed framework aims at being a foundation of a computer-based system that enables an increase of workers safety and well-being in industrial environments. Further aim is to enable an increase in production levels, together with improvement of ergonomics of the workplace. Specifically targeted environments are industrial workplaces that include repetitive tasks, which are in most of the cases monotonic in nature. Implicit HCI model could enable development of a specific technical solution that is meant to be an integral and inseparable part of a future workplace and should serve to predict human errors and communicate a warning to a worker. As such, system is meant to increase situational awareness of the workers and prevent errors in operating that would otherwise lead to work-related injuries (including causalities)
Neuroergonomics method for measuring the influence of mental workload modulation on cognitive state of manual assembly worker
In this study, we simulated a manual assembly operation, where participants were exposed to two distinct ways of information presentation, reflecting two task conditions (monotonous and more demanding task condition). We investigated how changes in mental workload (MWL) modulate the P300 component of event-related potentials (ERPs), recorded from wireless electroencephalography (EEG), reaction times (RTs) and quantity of task unrelated movements (retrieved from Kinect). We found a decrease in P300 amplitude and an increase in the quantity of the task unrelated movements, both indicating a decrease in attention level during a monotonous task (lower MWL). During the more demanding task, where a slightly higher MWL was imposed, these trends were not obvious. RTs did not show any dependency on the level of workload applied. These results suggest that a wireless EEG, but also Kinect, can be used to measure the influence of MWL variation on the cognitive state of the workers
THE ANATOMY OF RENAL ARTERIES IN ADULTS
Detailed extraparenhymal renal hilar dissection was performed on 110 fixed cadaveric kidneys (60 from male cadavers and 50 from female cadavers). We analyzed the number of renal arteries, angles between renal arteries and abdominal aorta, length and diameter of the renal arteries. Multiple renal arteries were pre-sent in 20.9% of cases, with a slightly higher incidence on the right side (21.8%: 20.0%). The angle between the aorta and the RRA varied from 30° to 100° with a mean of 64.1°, while the angle between the abdominal aorta and the LRA was 40° to 115°, with a mean of 67.3°. The external caliber of the RRA at the point of origin from the abdominal aorta was 5 mm to 9.1 mm, with a mean of 6.8 mm. The same caliber of the LRA was 3.7 to 9.6 mm with a mean of 7.0 mm. The average length of the renal artery from the point of origin from the abdominal aorta to the branch-ing point was 36.2 mm for the right renal artery and 30.7 mm for the left renal artery. The average length of the renal artery from the point of origin from the abdominal aorta to the renal hilum was 65.1 mm for the right one and 54.7 mm for the left one. Knowledge of the number of renal arteries, their mode of entry into the kidney, the angles they build with the abdominal aorta, their diameter and length has practical applications in interven-tional radiology and surgery of the kidney and its environment
Do Micro-Breaks Increase the Attention Level of an Assembly Worker? An ERP Study
This study investigates the influence of micro-breaks on the attention of an assembly worker, by utilizing wireless electroencephalographic (EEG) measurements. The EEG feature of interest for this study was the P300 event-related potential (ERP) component and P3a and P3b sub-components, as these components reflects the ones attention level. Nine students participated the study and completed the simulated manual assembly task, replicated from one of our industrial partner. We used sustained attention to response task (SART), instead of real industrial information that indicates the beginning of the operation. SART paradigm is "go/no-go" task, and in this version of SART, participants are required to respond to all "go" stimuli, in sense of initiating the action of manual assembly operation, and to withhold the action otherwise. The "no-go" condition was considered as micro-break period, since the participants had approximately five seconds to rest during a continuous simulated working routine. Fifty ERPs preceding and following the "no-go" condition were compared. The results revealed that, on the group level, the values of the amplitude of the P3b sub-component, which is related to the higher-level attention processing, were significantly higher for the ERPs following than preceding the micro-break period. This finding indicates that the frequent micro-breaks increase the attention of the manual assembly workers
Investigating Brain Dynamics in Industrial Environment - Integrating Mobile EEG and Kinect for Cognitive State Detection of a Worker
In the present work we used wearable EEG sensor for recording brain activity during simulated assembly work, in replicated industrial environment. We investigated attention related modalities of P300 ERP component and engagement index (EI), which is extracted from signal power ratios of alpha, beta and frequency bands. Simultaneously, we quantified the task unrelated movements, which are previously reported to be related to attention level, in an automated way employing kinect TM sensor. Reaction times were also recorded and investigated. We found that during the monotonous task, both the P300 amplitude and EI decreased as the time of the task progressed. On the other hand, the increase of the task unrelated movement quantity was observed, together with the increase in RTs. These findings lead to conclusion that the monotonous assembly work induces the decrease of attention and engagement of the workers as the task progresses, which is observable in both neural (EEG) and behavioral (RT and unrelated movements) signal modalities. Apart from observing how the attention-related modalities are changing over time, we investigated the functional relationship between the neural and behavioral modalities by using Pearson's correlation. Since the Person's correlation coefficients showed the functional relationship between the attention-related modalities, we proposed the creation of the multimodal implicit Human-Computer Interaction (HCI) system, which could acquire and process neural and behavioral data in real-time, with the aim of creating the system that could be aware of the operator's mental states during the industrial work, consequently improving the operator's well-being
Communicating the user state: Introducing cognition-aware computing in industrial settings
Wearable sensors provide the possibility to move from conventional, explicit human computer interaction (HCI), to more natural implicit HCI. In an implicit HCI context, the computer interprets human physiological and behavioral data as its input, enabling the development of cognition-aware computing for the user state monitoring. In this work, we made a first step towards development of the cognition-aware computing in the industrial environments, through the introduction of a sensitive workplace. For this, we replicated the real-life workplace and equipped it with wearable electroencephalography (EEG) and motion sensor (Kinect) recording. We further investigated interaction between brain dynamics, as reflected in P300 event-related potential (ERP) component amplitude and engagement index (El), and behavioral modalities of movement energy, all of which reflects the user state. The ultimate goal of the study is a proposal of the system for on-line detection of deviations in user state, ultimately preventing operators' errors and improving working experience
Concomitant multiple anomalies of renal vessels and collecting system
© 2020 Via Medica Although anomalies of renal vessels and collecting system are relatively frequent, their concomitant occurrence is a rare event. During dissection of a 75-year-old male formalin-embalmed cadaver, we found multiple variations in the renal vessels and renal collecting system. Both kidneys were normal in size and anteriorly malrotated, with duplex collecting system and duplex ureter. One ureter drained the upper part of the kidney and the second ureter drained the lower part of the kidney. Superior and inferior collecting systems were separated by renal parenchyma. The right kidney had two renal arteries, the first renal artery (main renal artery) originating from the abdominal aorta, passing behind the inferior vena cava (IVC) and entering the kidney through the superior and inferior renal hilum. The second artery was the inferior polar artery. In addition, the right kidney had two renal veins as well. Three renal tributaries emerged from the upper and lower portion of the right renal hilum, and they joined to form the main renal vein which drained into the IVC. The lower renal vein was the inferior polar vein. The left kidney had four renal arteries (two hilar arteries and two polar arteries). The main left renal vein emerged from both superior and inferior left renal hilum, passed in front of the abdominal aorta and drained into the IVC. The left kidney also had the inferior polar vein which was divided behind the aorta (retro aortic vein) into two venous trunks. These venous trunks drained separately into posteromedial aspect of the IVC. Finally, the right testicular vein was formed by two tributaries and drained into the IVC, whereas the two left testicular veins drained separately into the left main renal vein