Comparative analysis of mental workload and performance between young and elderly drivers: Implications for road safety and age-related driving challenges.

BACKGROUND: Driving represents a multifaceted cognitive endeavor, demanding heightened vigilance and swift responses. Considering the high statistics of driving accidents and heavy loads, as well as the effect of the driver's age on the occurrence of accidents, it is important to investigate these factors to reduce accidents. OBJECTIVE: This study investigates the impact of mental workload on the performance of young and older drivers in a dynamic driving scenario to compare cognitive performance, workload perception, and driving outcomes between the two age groups. METHODS: Cognitive tests including the Stroop test, Continuous Performance test, and Focused Attention test were conducted, alongside the use of the DALI questionnaire to measure workload levels. Participants encompassed twenty male drivers, divided into two age groups: 20 to 35 years and 55 to 70 years, with varying years of driving experience. The study entailed a dynamic driving scenario involving a designated route in Tehran, Iran. RESULTS: Results exhibited differences in workload scores between the age groups, particularly in dimensions such as visual demand, auditory demand, attention, and interference. Older drivers demonstrated heightened cognitive and physical demands during driving, implying a greater need for attention and cognitive effort. CONCLUSION: The findings of this study indicated that navigating through congested roads and dense urban traffic significantly elevates the mental workload for drivers, consequently impacting their cognitive functioning. Given the critical need for attention in driving, this heightened workload can manifest as increased fatigue, increasing stress levels, and diminished concentration, all of which substantially raise the risk of vehicular accidents. Furthermore, the study highlighted a particular concern for older drivers, whose diminished cognitive capacities further raise their vulnerability to accidents under such demanding driving conditions.

The potential impact of emotionally loaded stimuli on over/under-estimating neutral situations among power plant control-room operators.

BACKGROUND: Human emotions vary on a contextual basis. The significance of emotions becomes even more salient in Control Room Operators (CROs) in power plants. OBJECTIVE: This study investigated the effects of emotionally loaded pictures on over/underestimating neutral situations. METHODS: Twenty CROs voluntarily enrolled in the present study. Twenty-one blocks were considered, including ten emotionally loaded and 11 neutral blocks. The stimuli were alternatively submitted to subjects in random order. Each block comprised 13 images from the International Affective Picture System (IAPS), which were shown for 5 seconds. Subjects were required to complete the Self-Assessment Manikin (SAM) after exposure to the first and the last neutral blocks, which were identical. RESULTS: Our analyses showed significant differences between IAPS arousal and SAM1 and SAM2 arousal ratings (p SAM1&IAPS = 0.00, p SAM2&IAPS = 0.02). There was no significant relationship between the first and the second arousals, and emotionally loaded images corresponded to no significant difference in terms of valence. CONCLUSION: The findings suggested that the participants overestimated neutral situations compared with IAPS only in arousal level. Furthermore, CROs can still retain their ability to assess neutral situations in the case of viewing emotional stimuli, especially in valence level, at least half an hour after the first rating. A study design with pure negative/positive and high arousal levels may still provide even more significant results.

The Validity and Inter-Rater Reliability of a Video-Based Posture-Matching Tool to Estimate Cumulative Loads on the Lower Back.

Background: Low back pain (LBP) is known as one of the most common work-related musculoskeletal disorders. Spinal cumulative loads (CLs) during manual material handling (MMH) tasks are the main risk factors for LBP. However, there is no valid and reliable quantitative lifting analysis tool available for quantifying CLs among Iranian workers performing MMH tasks. Objective: This study aimed to investigate the validity and inter-rater reliability of a posture-matching load assessment tool (PLAT) for estimating the L5-S1 static cumulative compression (CC) and shear (CS) loads based on predictive regression equations. Material and Methods: This experimental study was conducted among six participants performing four lifting tasks, each comprised of five trials during which their posture was recorded via a motion capture (Vicon) and simultaneously a three-camera system located at three different angles (0°, 45°, and 90°) to the sagittal plane. Results: There were no significant differences between the two CLs estimated by PLAT from the three-camera system and the gold-standard Vicon. In addition, ten raters estimated CLs of the tasks using PLAT in three sessions. The calculated intra-class correlation coefficients for the estimated CLs within each task revealed excellent inter-rater reliability (> 0.75), except for CS in the first and third tasks, which were good (0.6 to 0.75). Conclusion: The proposed posture-matching approach provides a valid and reliable ergonomic assessment tool suitable for assessing spinal CLs during various lifting activities.

An innovative sit-standing seat in urban buses: A new design to prevent falls and non-collision injuries.

BACKGROUND: Due to the rapid growth of metropolises and the insufficiency of public transportation, nowadays, many people travel on these vehicles in a standing position. This position leads to discomfort and the risk of falling or non-collision incidents for the passengers. OBJECTIVE: The present study was conducted to analyze an innovative sit-standing seat to prevent falls and non-collision injuries in standing passengers. METHODS: A total of sixteen participated in this study. EMG signal and Borg scale were used to assess muscle activity and discomfort, respectively. RESULTS: The mean Borg scale score for perceived discomfort was lower in the sit-standing position than the standing position in all body organs, except for the hips. Also, in the sit-standing position compared to the standing position, the muscle activity of the soleus and medial gastrocnemius muscles was significantly lower in the constant velocity and entire phases in both legs, lower in the right leg in the acceleration phase and lower in the left leg in the deceleration phase. CONCLUSIONS: So, this seat can be used as an innovative idea to improve the ergonomic condition of standing passengers to prevent falls and non-collision injuries on transit buses.

The effect of auditory stimulation using delta binaural beat for a better sleep and post-sleep mood: A pilot study.

Background: Although previous evidence confirms the effects of sleep deprivation on mental health and wellbeing, due to the interaction effects of sleep and mood on each other, the influence of sleep improvement has received less attention. Objective: This study aimed to find whether binaural beat technology can enhance sleep quality and thus post-sleep mood. Methods: Twenty healthy students participated in this pilot study. All subjects were investigated for two weeks (a baseline week and an experimental week). In the first week, there was no intervention, but in the second week, all subjects were exposed to a 90 min binaural beat in the delta frequency range. The individuals' sleep was monitored for two weeks using a sleep diary form, and a Profile of Mood State questionnaire was employed to assess their mood at the end of the first and second weeks. Results: Auditory stimulation with delta binaural beat enhanced sleep parameters such as sleep failure, the number of awakenings, real duration of sleep, sleep quality, and feeling following the waking of the individuals. Finally, students' moods improved by reducing anxiety and anger, but other mood parameters did not indicate a significant difference. Conclusion: The findings of this study confirmed that auditory stimulation with a delta binaural beat seems to be a low-cost and alternative method for medicine and other treatment methods with side effects. Application: This study demonstrates the use of technology with a neuroergonomics approach to improve sleep and mood disorders.

The effect of listening to Iranian pop and classical music, on mental and physiological drowsiness.

Driver's drowsiness is one of the high-risk road behaviors that quadruples the risk of road accidents. Measures to deal with drowsiness during driving include listening to music. The present study investigates the effect of two types of music, namely Iranian high-tempo pop and classical music, on mental and physiological drowsiness during driving. Twelve male students at Tehran University of Medical Sciences within the normal range of the Epworth Drowsiness Scale (ESS) participated in this study. Two types of music (classical and pop) were assessed on two separate days with an interval of one week. The mental aspect of drowsiness was evaluated using the Karolinska Sleepiness Scale (KSS), the physiological aspect by monitoring the EEG and heart rate, and the functional aspect through the mean and standard deviation of speed and the Standard Deviation of Lateral Position (SDLP) in a driving simulator. The results showed that the brain waves (four algorithms (1) (θ + α)/ß, (2) α/ß, (3) (θ + α)/(α + ß) and (4) θ/ß), the KSS score, SDLP and standard deviation of speed all decrease while the mean heart rate increases when listening to music during driving compared to driving without music. No significant difference was observed in the mean speed when exposed to music. Moreover, no difference was observed between the effect of the two music styles, i.e. Iranian classical and pop music. Listening to Iranian classical and pop music while driving improves the driver's performance and reduces drowsiness. The present study showed that higher tempo music during driving can reduce drowsiness and change physiological responses and driving performance.

Determining the Efficiency of Ergonomic Belt During Patient Handling and its Effect on Reducing Musculoskeletal Disorders in Nurses.

INTRODUCTION: Nursing personnel are always at risk for work-related musculoskeletal disorders, and patient transportation is one of the major risk factor for these disorders. OBJECTIVE: The aim of this study was to evaluate the ergonomic belt to improve patient transferring conditions. METHODS: The subjects included 60 health care workers (HCW) of a hospital with patient transfer experience. The ergonomic belt was examined to help move the patient from one bed to another. The prevalence of musculoskeletal disorders was assessed through the Nordic questionnaire, the degree of perceived exertion through the Borg criterion, and the patient's movement through the MAPO index before and after the intervention. RESULTS: The results showed a significant decrease in Borg scale scores and MAPO index in two factors of education and auxiliary tools and overall scores of this index. We also saw a significant reduction in musculoskeletal disorders in the neck, shoulders and arms, waist, hands and wrists, thighs, knees and legs. There were no significant differences in the elbow and forearm before and after using the ergonomic belt. CONCLUSION: In general, it can be concluded that the use of ergonomic belt had helped to reduce the risk of musculoskeletal disorders, as well as reducing the perceived exertion of nurses and other relevant personnel.

An Assessment of Ergonomics Climate and Its Association with Self-Reported Pain, Organizational Performance and Employee Well-Being.

Previous studies have demonstrated that a positive ergonomics climate with an equal focus on improving operational performance and employee well-being is beneficial to both employee health and organizational performance. This study aimed to assess the ergonomics climate at two power plants and examine its association with self-reported pain, performance, and well-being. At two power plants in Iran, survey responses from 109 and 110 employees were obtained. The questionnaires contained data on ergonomics climate, organizational performance, employee health, and self-reported pain. Results showed that the mean ergonomics climate scores between the Besat and Rey power plants were significantly different (p < 0.001). The overall ergonomics climate score, and all subscales scores, were positively associated with organizational performance (p < 0.001). The overall ergonomics climate score, and some of its subscales, were significantly associated with employees' general health (p < 0.001). The ergonomics climate score was significantly higher in the group of employees who reported musculoskeletal pain than those who did not report musculoskeletal pain (p < 0.05). Investigation of ergonomics climate can provide organizations with a baseline for prioritizing their values and finding areas for improving organizational performance and employee health.

The combined effect of industrial noise type, level and frequency characteristics on hand motor skills: A lab trial study.

BACKGROUND: The study aimed to assess the interactive effects of industrial noise type, level and frequency characteristics on hand motor skills using the Minnesota Manual Dexterity Test and the Hand Tool Dexterity Test. METHODS: A total of ten nonsmoking male volunteers with normal hearing and vision were selected for this study. The study followed a full 3×3×2 factorial design. Independent variables were noise type (steady, intermittent and fluctuating), noise level (75, 85 and 95 dBA) and frequency characteristics ("roar" <2000 Hz and "hiss" >2000 Hz). RESULTS: For Minnesota Manual Dexterity Test, the lowest speed is related to steady hiss noise at 75 dBA and the highest speed is related to fluctuating roar noise at 95 dBA. The speed is being significantly affected by the frequency characteristic (P = 0.041) and noise type (P = 0.025). The effect of hiss noise on speed is greater than roar noise (P = 0.038). There is a significant difference (P = 0.035) between continuous noise and fluctuating noise. For the Hand Tool Dexterity Test, the lowest speed is related to fluctuating hiss noise at 95 dBA and the highest speed is related to steady roar noise at 95 dBA. The speed is being significantly affected by the frequency characteristic (P = 0.002), noise type (P = 0.0001) and noise level (P = 0.005). The effect of hiss noise on response variable to be greater than roar noise (P = 0.008). There is a significant difference (P = 0.0001) between steady noise and the two other types of noise, and also there is a significant difference between 75 dBA and 85 dBA level (P = 0.003). CONCLUSIONS: The results showed that on hand motor skills, speed response was influenced by three characteristics: the type of noise, frequency characteristics and noise level. Also, the effect of the hiss noise was more than the roar noise.

Relationship between mental workload and salivary cortisol levels: A field study.

BACKGROUND: Mental workload (MW) assessment is a key point in research and development of human-machine interfaces in the workplace. OBJECTIVE: This study aimed to examine the relationship between mental workload and the amount of salivary cortisol amongst technicians of an Iranian combined cycle power plant. METHODS: A total of 18 technicians participated in this pilot study. First, task analysis was carried out to determine operation steps that forced us to separate them in to two groups. Next, the Visual, Auditory, Cognitive, and Psychomotor (VACP) technique and NASA Task Load Index (NASA-TLX) questionnaire were used to examine their mental workload. Then, the operator's salivary samples were collected at four specific times of both off and working days. Finally, the relationship between mental workload and salivary cortisol was examined with the analysis of Pearson correlation. RESULTS: The results of mental workload assessment with subjective methods showed a high level of mental workload amongst all technicians. No significant association was observed between the NASA-TLX questionnaire and VACP technique with concentration of salivary cortisol (p = 0.081). CONCLUSION: Based on the results, it can be concluded that salivary cortisol might not be an appropriate physiological method to assess mental workload, since cortisol levels are highly dependent on individuals' circadian rhythm.

The neural basis of hazard perception differences between novice and experienced drivers - An fMRI study.

The neural mechanisms underlying hazard perception are poorly understood as to how experience leads to better driving skills. In this study we used functional magnetic resonance imaging (fMRI) to examine experience-related changes in brain activation during hazard perception task between novice and aged drivers. Additionally, region of interest (ROI) and seed-to-voxel analyses were conducted to examine experience-related functional connectivity changes during visual attention and saliency networks between novice (n=15, age 22.13 ± 3.38 years years) and experienced (n=16, age 41.44 ± 5.83 years) drivers. Experienced drivers had significantly lower hazard perception reaction time (1.32 ± 1.09 s) and miss rates (11.42 ± 8.36 %) compared to the novice (3.58 ± 1.45 s and 39.67 ± 15.72 %, respectively). Blood oxygen level dependent (BOLD) activation increased in occipital, parietal and frontal areas when executing hazard perception task in both groups. In general, during the task execution, experienced drivers showed greater activation in the occipital lobe, supramarginal gyrus (SMG), right anterior insular cortex (AIC), anterior cingulate cortex (ACC) and cerebellar regions compared to the novice drivers indicating more efficient visual attention and decision-making process during hazard perception task. Seed based functional analyses during the hazard perception task revealed greater connectivity between the ACC and the entire salience network (visual attention network) in the experienced group. Additionally, ACC had higher functional connectivity with the right frontal eye field (FEF), bilateral intraparietal sulcus (IPS) and lateral occipital areas in the experienced group. Our results suggest that better hazard perception in the experienced drivers is due to increase in the activation of executive attention regions and higher functional connectivity between bilateral occipital cortices and salience network. In conclusion, better hazard perception is highly dependent on emotional awareness, perception of motion velocity, spatial representation of the environment and executing control.

Determination of critical time points in non-collision incidents of elderly passengers in standing position on urban bus.

Objective: Due to the reduced physical ability of elderly, the occurrence of non-collision incidents is higher for these passengers in standing position. Therefore, the purpose of the present study is to determine the critical time points of non-collision incidents using the level of leg muscle activity in elderly standing passengers on urban bus.Methods: To determine the critical time points in the occurrence of non-collision incidents, the level of muscular activity of the standing passengers was analyzed using a surface electromyography (surface EMG) device during the movement scenario of the bus. The results of assessing the leg muscle activity was analyzed in SPSS software.Results: The contraction pattern of the leg muscles in standing passengers was consistent with Newton's First Law. The results showed that the level of muscular activity decreased in the right leg muscles when changing the phase of bus motion from acceleration to constant velocity. This level of muscular activity in the left leg muscles increased when constant velocity changed to deceleration. These changes were quite significant in the medial gastrocnemius and soleus muscles (P < 0.05).Conclusions: According to these findings, it was found that the acceleration and deceleration phases, especially the starting and changing phases of bus motion, are the most critical time points in the occurrence of non-collision incidents in elderly standing passengers on urban bus.

Impact of music type on motor coordination task performance among introverted and extroverted students.

Purpose. People are interested in music. In this study, we assessed the impact of music type on objective performance. Materials and methods. We distributed 64 medical science students in Tehran into four groups: Iranian pop music, traditional music, Mozart's classical music and control groups. All participants performed the two-arm coordination test once without music and once with music (except for the control group), with an interval of 1 week. In the music groups, music was playing during the performance of the test. Participants were categorized as either introverted or extroverted and were distributed equally in the groups. Results. There was a significant decrease of test time in the second trial, observed in all music groups, and no significant difference identified in the control group. The traditional music group had less difference of mean time compared to the pop music group. The differences in the traditional and classical groups were not significantly different. In the music groups, both extroverted and introverted students decreased their test time significantly after music intervention, but extroverted students decreased more. Conclusion. Listening to music would enhance the speed of performance. Music with a higher tempo, such as pop music, increased the speed more.

Assessment of occupational safety, health, and ergonomics issues in agriculture in some cities of Iran.

BACKGROUND: Iran has a variety of climates which support agriculture in different seasons. Hence, a significant proportion of people, especially in rural areas, are engaged in farming. Agriculture is considered one of the most insecure job sectors in developing and developed countries. OBJECTIVE: Since there is no comprehensive study on safety, health, and ergonomics issues in Iran's agriculture, it is necessary to use checkpoints to assess occupational safety, health, and ergonomics issues in Iran's agriculture. METHODS: In this study, 430 villages from seven provinces of Iran were selected to study safety, health, and ergonomics in agriculture using ergonomic checkpoints. The checkpoints were collected with the help of rural health centers. RESULTS: The results of the study showed that the villages of Kurdistan Province had the best safety, health, and working conditions (66.12%); and Khuzestan province villages had the worst safety, health, and working conditions (38.16%). Among the ergonomic checkpoints in agriculture, the control of hazardous chemicals (CHC) index with 71.41% and work organization and work schedule (WOWS) index with 35.25% represented the best and worst ergonomic conditions of the study villages, respectively. Furthermore, the general index of ergonomics in agriculture for the study villages was 53.64%. Therefore, Khuzestan Province and the WOWS index top the priorities for corrective actions to improve the safety, health and working conditions in agriculture. CONCLUSIONS: The ergonomics indices in Iranian agriculture are important, and should be prioritized for corrective actions.

Evaluation of occupational exposure to different levels of mixed organic solvents and cognitive function in the painting unit of an automotive industry.

Background: The cognitive function could be affected following exposure to organic solvents.The purpose of this study was to examine the cognitive performance of workers exposed to different levels of organic solvents in a painting unit of an automotive industry. Methods: This case-control study was conducted, in 2017, on 121 and 111 workers from the painting and assembly units of an automotive industry as the case and control groups,respectively. Exposure of workers to organic solvents were determined according to National Institute for Occupational Safety and Health (NIOSH) method. The cognitive performance of the studied population was evaluated by the computerized tests. Results: The obtained scores of the N-Back in 1 and 2 blocks and the simple reaction time tests(SRTTs) were significantly differed in the exposed group (p<0.05). No significant difference was observed between case and control groups in the Stroop test score (p> 0.05). Moreover, a significant relationship between the hazard quotient and the cognitive function test scores were observed except the Stroop test. Conclusion: Exposure to organic solvents affect the cognitive functions even below the Occupational Exposure Limits (OELs). Moreover, workers with high exposure levels of organic solvents had highest risk of poor memory and reaction time.

Combined effect of whole-body vibration and ambient lighting on human discomfort, heart rate, and reaction time.

PURPOSE: This study aimed to investigate the effect of whole-body vibration and ambient lighting, as well as their combined effect on human discomfort, heart rate, and reaction time in laboratory conditions. METHODS: 44 men were recruited with an average age of 25.4 ± 1.9 years. Each participant was subjected to 12 experimental steps, each step lasting five minutes for four different vibration accelerations in X, Y, and Z axes at a fixed frequency; three different lighting intensities of 50, 500, and 1000 lx were also considered. At each step, a visual computerized reaction test was taken from subjects and their heart rate recorded by pulse oximeter. In addition, the discomfort rate of subjects was measured using Borg scale. RESULTS: Increasing vibration acceleration significantly increased the discomfort rate and heart beat but not the reaction time. Lack of lighting caused more discomfort in the subjects, but there was no significant correlation between lighting intensity with heart rate and reaction time. The results also showed that the combined effect of vibration and lighting had no significant effect on any of the discomfort, heart rate, and reaction time variables. CONCLUSIONS: Whole-body vibration is an important factor in the development of human subjective and physiological reactions compared to lighting. Therefore, consideration of the level of vibration to which an individual is exposed in workplaces subject to vibration plays an important role in reducing the level of human discomfort, but its interaction with ambient lighting does not have a significant effect on human subjective and physiological responses.

Safety Evaluation of the Lighting at the Entrance of a Very Long Road Tunnel: A Case Study in Ilam.

BACKGROUND: At the entrance of a tunnel, reflection of sunlight from the surrounding environment and a lack of adequate lighting usually cause some vision problems. The purpose of this study was to perform a safety evaluation of lighting on a very long road in Ilam, Iran. METHODS: The average luminance was measured using a luminance meter (model S3; Hagner, Solna, Sweden). A camera (model 108, 35-mm single-lens reflex; Yashica, Nagano, Japan) was used to take photographs of the safe stopping distance from the tunnel entrance. Equivalent luminance was determined according to the Holliday polar diagram. RESULTS: Considering the average luminance at the tunnel entrance (116.7 cd/m2) and using Adrian's equation, the safe level of lighting at the entrance of the tunnel was determined to be 0.7. CONCLUSION: A comparison between the results of the safe levels of lighting at the entrance of the tunnel and the De Boer scale showed that the phenomenon of black holes is created at the tunnel entrance. This may lead to a misadaptation of the drivers' eyes to the change in luminance level at the entrance of the tunnel, thereby increasing the risk of road accidents in this zone.

Survey of discomfort glare from the headlamps of cars widely used in Iran.

OBJECTIVE: On 2-lane roads, discomfort glare can cause annoyance, discomfort, inconvenience, stress, and fatigue to drivers, posing a risk of accidents. The aim of this study is to evaluate discomfort glare from the headlamps of cars widely used in Iran. METHODS: The discomfort glare of new vehicles including Pride Saba model GTX, Pride Model 131SL, Samand Soren, Peugeot 405, Megane, and Peugeot Pars was examined at distances of 5 to 100 m at a background luminance of 50 cd/m2 (late twilight/early dawn lighting) and 1 cd/m2 (nighttime) using Schmidt-Clausen and Bindels model and de Boer's subjective scale. RESULTS: According to the de Boer scale, at a background luminance of 50 cd/m2, the discomfort glare for all studied vehicles was between 1.98 and 4.05 in high-beam mode and between 3.5 and 5.4 in low-beam mode. At a background luminance of 1 cd/m2, discomfort glare was between 0.41 and 2.48 in high-beam mode and between 1.93 and 3.84 in low-beam mode. In high-beam mode, the average levels of discomfort glare of these vehicles gradually increased when the distance between cars was reduced by up to about 20 m. In low-beam mode, there was no discomfort glare up to a vehicle distance of 40 m. In addition, at an angle of 1.15°-5.73° between the line of sight and light of vehicles in high-beam mode, the level of discomfort glare was increased, but at an angle of 5.73°-22.9° the level of discomfort glare was reduced. In low-beam mode at an angle of 2.86°-22.9°, the level of discomfort glare was almost identical. The results show that in high-beam mode and with a 100-m distance between vehicles as well as in low-beam mode at intervals of less than 40 m between cars, discomfort glare is created. CONCLUSION: It can be concluded that by providing solutions such as installing road lighting system, an increase in luminance of roads, separating or widening road lanes, increasing the lateral distance between vehicles, and increasing the angle between lighted vehicles and drivers can noticeably reduce discomfort glare.

The relationship between psychosocial work factors, work stress and computer-related musculoskeletal discomforts among computer users in Malaysia.

Increasing numbers of workers use computer for work. So, especially among office workers, there is a high risk of musculoskeletal discomforts. This study examined the associations among 3 factors, psychosocial work factors, work stress and musculoskeletal discomforts. These associations were examined via a questionnaire survey on 30 office workers (at a university in Malaysia), whose jobs required an extensive use of computers. The questionnaire was distributed and collected daily for 20 days. While the results indicated a significant relationship among psychosocial work factors, work stress and musculoskeletal discomfort, 3 psychosocial work factors were found to be more important than others in both work stress and musculoskeletal discomfort: job demands, negative social interaction and computer-related problems. To further develop study design, it is necessary to investigate industrial and other workers who have experienced musculoskeletal discomforts and work stress.