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Introduction and purpose: Noise is one of the most harmful physical factors in workplaces in both developed and developing countries. Still, low-frequency noise has not received enough attention, and the current regulations on its control are inadequate. To address this issue, the present study was conducted to examine the physiological response and cognitive functions of individuals before and after exposure to low-frequency noise. Methods: This study was conducted in the solar year 1401 and involved 40 students from Mazandaran University of Medical Sciences. Low-frequency noise with a level of 65 dB A was played for one hour. The patients' heart rates, blood pressure, and core temperatures were collected before and after exposure to low-frequency noise. Moreover, the continuous performance test was used to examine their cognitive performance. The data was analyzed using the Friedman and Voilcoxon tests in SPSS 25 software. Results: Low-frequency noise adversely impacted individual cognitive performance, increasing response error, omission error, and reaction time. However, according to the Wilcoxon test, only the increase in reaction time was statistically significant (P0.05). Conclusion: Exposure to low-frequency noise generates greater discomfort than background noise with the same intensity level and has adverse effects on the individual's performance. Thus, the adverse effects of low-frequency noise are particularly significant in workstations that require mental processing of information and specific attention, such as control rooms and offices.

Considering the current developments and the growing influence of the emerging technology of artificial intelligence in the military field, many theorists identify it as the fourth military revolution. So, it is necessary to examine the consequences and importance of artificial intelligence in the war game and subsequently combat readiness. This study aims to investigate the effect of using artificial intelligence in the war game on the cognitive performance of commanders and warriors in future naval battles. In this exploratory- meta combination research, the statistical population consists of valid qualitative studies published in the field of artificial intelligence application in war games and military training in ۲۰۱۰ to ۲۰۲۳۰ Based on the meta-combination results, the application of artificial intelligence in the naval war game can improve the performance of commanders in the future naval battlefield by enhancing social cognitive learning, promoting mental resilience, improving creativity, and improving simulation. Studies have shown that artificial intelligence is an effective method for developing accurate meta-models of computer simulations of combat operations and war games, because they have capabilities such as better memory, deep and continuous learning, etc. [ABSTRACT FROM AUTHOR]

Introduction: Cognitive-motor skills form a large part of human life, and for many years researchers and educators have attempted to identify factors that influence their implementation. Aim: The present study aimed to investigate the effectiveness of cognitive attentional focus instructions and exercise schedule on cognitive performance in elderly men. Method: The present study was a semi-experimental method with a pretest-posttest design and 4 experimental groups. Sixty elderly men from Ahvaz city aged 60-80 years were selected by voluntary random sampling in 2020 and randomly divided into four experimental groups (variable practice-internal attention, variable practice-external attention, constant practice-external attention, and constant practice-internal attention). The dartboard attached to the wall served as a tool. The research groups had 10 sessions and each session consisted of 3 blocks of 10 trials. Thus, the test was performed 48 hours after the subjects' last training session. Data were analyzed using one-way ANOVA and mixed repeated measures analysis of variance. Results: The results of one-way ANOVA showed that there was a significant difference between the groups in the posttest phase (P=0.001, F=11.43). Tukey's post hoc test was used to test the differences. The results showed a significant difference between the variable practice-external attention group with variable practice-internal attention (P=0.011), constant practice-external attention (P=0.001), and constant practice-internal attention (P=0.001) groups. However, no difference was found between the other study groups at this stage. Conclusion: Based on the research results, the combined group with variable practice-external attention performed better than the other groups. Considering that the variable practice-external attention training group showed better cognitive performance, geriatric sneakers and professionals are recommended to use the combined advantage of these two methods in their training plans.

The aim of this study was to investigate the structural relations between perfectionism levels and cognitive performance in individuals with symptoms of obsessive-compulsive disorder mediated by cognitive styles. The study population included students of University of Tabriz. Using convenience sampling, 360 subjects were selected. They completed Madsley's obsessivecompulsive disorder inventory, positive and negative perfectionism scale, and Felder-Solomon learning styles questionnaire online. Also, Wisconsin Card Sorting Test, Continuous Performance Task (CPT) and Wechsler Working Memory Test (WMT) were performed through computer software. Results showed that reflective cognitive style could mediate the relationship between positive perfectionism and cognitive performance. Besides, levels of perfectionism could significantly predict reflective cognitive style and cognitive performance significantly. Hence, it could be concluded that levels of perfectionism and reflective cognitive style in interaction, predict cognitive performance in individuals with symptoms of obsessive-compulsive disorder. It was also obtained that interventions in this field should consider the interactive effects of perfectionism and reflective cognitive style. [ABSTRACT FROM AUTHOR]

Introduction: Cognitive emotion regulation (CER) strategies define as cognition-based responses according to emotion-eliciting experiences that can change the type and severity of individuals’ reactions and behaviors. This modification may positively or negatively affect cognitive performance and therefore, it is a defining issue in the workplace. Notably, industries such as combined cycle power plants need to hire staff with a high cognitive ability to perform their duties in a highly efficient way. Since CER is of great importance for overall health and cognitive performance, we aimed to evaluate the state of CER among control room operators (CROs) in the Fars combined cycle power plant. Material and Methods: The CER questionnaire (CERQ) measures nine cognitive coping strategies (i.e., self-blame, other-blame, rumination, catastrophizing, positive refocusing, planning, positive reappraisal, putting into perspective, and acceptance) that are followed when an individual confronts negative events. The CERQ (short version) was administered to 57 male CROs at the Fars combined cycle power plant. The questionnaire also collected demographic data. Statistical analyses were performed using SPSS Version 25.0. For the normality test, Shapiro-Wilk was the method of choice. Results: Results of the CERQ scoring showed that the median with interquartile range (IQR) in appropriate and inappropriate categories were 3.50 (3.30-4.00) and 2.62 (2.25-3.06), respectively. Of note, age (39.07 ±6.19) and work experience (14.49±6.26) were not significantly correlated with the results of CERQ. Conclusion: Taken together, adaptive cognitive strategies (acceptance, positive refocusing, planning, positive reappraisal, and putting into perspective) were reported to be used more often than less adaptive strategies. In general, staff strategies were appropriate while facing a negative event. Although assessing CER in high-demand workplaces is necessary, factors such as managerial styles, job engagement, job satisfaction, and larger sample size should be further studied.

Introduction: Cognitive -motor skills form a large part of human life, and for many years researchers and educators have attempted to identify factors that influence their implementation. Aim: The present study aimed to investigate the effectiveness of cognitive attentional focus instructions and exercise schedule on cognitive performance in elderly men. Method: The present study was a semi -experimental method with a pretest -posttest design and 4 experimental groups. Sixty elderly men from Ahvaz city aged 60 -80 years were selected by voluntary random sampling in 2020 and randomly divided into four experimental groups (variable practice -internal attention, variable practice -external attention, constant practice - external attention, and constant practice -internal attention). The dartboard attached to the wall served as a tool. The research groups had 10 sessions and each session consisted of 3 blocks of 10 trials. Thus, the test was performed 48 hours after the subjects' last training session. Data were analyzed using one -way ANOVA and mixed repeated measures analysis of variance. Results: The results of one -way ANOVA showed that there was a significant difference between the groups in the posttest phase (P=0.001, F=11.43). Tukey's post hoc test was used to test the differences. The results showed a significant difference between the variable practice -external attention group with variable practice -internal attention (P=0.011), constant practice -external attention (P=0.001), and constant practice -internal attention (P=0.001) groups. However, no difference was found between the other study groups at this stage. Conclusion: Based on the research results, the combined group with variable practice -external attention performed better than the other groups. Considering that the variable practice -external attention training group showed better cognitive performance, geriatric sneakers and professionals are recommended to use the combined advantage of these two methods in their training plans. [ABSTRACT FROM AUTHOR]

Introduction: Having Control over performance is one of the most important factors for success in the shooting. Research had shown that the more information a person has about the function of their body, the better control they will have over it. This study aimed to determine the effect of heart rate biofeedback along with relaxation training on the performance and gaze behavior of shooters.Methods: 16 semi-skilled shooters with an average age of 18 to 40 years were selected using the available sampling method. Participants were homogeneously assigned to the training (heart rate biofeedback with abdominal relaxation training) and the control groups. Before and after the practice interventions, all participants performed 20 shots from a 10 meters distance, while shooting accuracy scores were measured by Scat software and their gaze behavior were measured by an eye tracking device. Then, participants of the experimental group performed 30 minutes of heart rate biofeedback and abdominal relaxation intervention for four weeks, and three sessions per week.Results: The results of two-way ANOVA showed that there was a significant difference in the shooting accuracy score of players’ performance, but there was no significant difference in the gaze behavior of shooters between intervention and control groups in the post-test compared to the pre-test.Conclusion: Overall, biofeedback with relaxation training was able to improve the performance of semi-skilled shooters. However, there was no significant difference in the gaze behavior of shooters due to the improvement of the indicators of this variable.

Introduction: One of the secondary consequences of burnout is a significant reduction in cognitive functions, the most obvious and important of which is the cognitive function of attention and control, which can play a vital role in efficiency and prevention of errors at work in many occupations. On the other hand, a neurological examination is needed to understand better the relationship between burnout and its consequent depressive disorder regarding the cognitive function of the attention network of these individuals. Depressed people usually have neuropsychological disorders. Therefore, the present study aimed to investigate the cognitive performance of executive control of health care workers with shift jobs on the verge of burnout using the Attention Network Test (ANT) Event-Related Potential (ERP). Materials and Methods: The sample included 26 health care providers on the verge of burnout in Rasoul Akram Hospital in Tehran (15 without depression and 11 with mild to moderate depression) selected by purposive sampling. The rate of burnout was assessed by the Maslach Scales (1981); depression was evaluated by the Depression, Anxiety and Stress Scale-21 (DASS-21); attention was assessed by the Network Attention Test (ANT) and simultaneously with the behavioral test. We investigated the event-related potential (ERP) indicators of attention processing. Independent t-test and paired t-test were used for data analysis. Results: The results of behavioral performance revealed no significant difference between the two groups in the three attention networks; however, Significant differences can be seen in ERP brain waves related to the executive function of attention, especially by increasing the SP wave and N2 wave component compared to normal individuals without depression Conclusion: : Significant differences can be seen in ERP brain waves related to the executive function of attention, especially by increasing the SP wave and N2 wave component compared to normal individuals without depression. According to the study results, it can be stated that to improve cognitive performance in people's work environments, measures should be taken to reduce burnout and depression, and employees should perform their activities with better performance and help the quality growth of the work environment.

Introduction: The noise could affect some aspects of human health, including the cognitive performance. In addition to sound pressure level and exposure time, the psychoacoustic features of noise may cause destructive effects on humans. A few recent studies have been conducted on effect of sound quality on cognitive performance. This study aims to find the noise loudness and sharpness levels as the most destructive effects on human cognitive performance. Material and Methods: This was a cross-sectional study on 10 male students of Tehran University of Medical Sciences. The Noises were generated in two channels that the left channel produced the pink noise as a background noise. The pink noise loudness and sharpness were 19.7 sone and 2.49 acum, respectively. The right channel generated noises with different loudness and sharpness levels the noise loudness ranged from 8.87 to 67.9 sone and the noise sharpness ranged from 1.07 to 6.4 acum. Finally, ten noises with different loudness and sharpness were applied. The students were exposed to ten different types of noise and a silent condition. The Mathematical Problem Solving Task (MPST) test was performed to assess cognitive performance. The reaction time and the accuracy rate were measured after 5 minutes of noise exposure. Data were analyzed by SPSS (ver. 22). P< 0.05 was considered as significant level. Results: The mean reaction time and the mean accuracy rate increased with the sharpness level. However, alteration in the loudness and sharpness levels had no significant effect on the speed and accuracy of students. Performance speed increased in noise 3 with the highest loudness (L=67.9, SH=1.07) in comparison with the silent condition (p-value=0.05). The mean accuracy rate in exposure to the noise 9 reduced in comparison with silence (p-value=0.04) Conclusion: Different levels of psychoacoustic features had no significant effect on the cognitive performance parameters. Although, the accuracy rate and the reaction time decreased in noises 9, the sharpest noise, and 3, the loudest noise, in comparison to the silence, respectively.

Introduction: Recent evidence indicates that lighting can affect physiological and neurobehavioral human functions, referred to as non-image forming (NIF) effects of lighteffects. This study aimed to determine the effects of illumination levels and correlated color temperature (CCT) on alertness and performance under NIF conditions. Material and Methods: In this study, 22 participants were exposed to light at various levels of illumination, including very low illuminance (

Background: The pilot's performance cognitive is an important construct that plays a vital role in preventing aviation incidents. Various studies have identified factors affecting pilot cognitive performance, but there is a research gap regarding interaction of these factors and their sequence. Aims: The aim of present study was to develop a structural model for predicting cognitive performance of Iranian airline pilots based on the sources of stress and situation awareness considering the mediating role of mental fatigue and flight factors. Method: The method of present study was descriptive-correlational. The statistical population of study included all male civilian pilots working in Iranian airlines in 2019. Using a convenience sampling method, 310 people participated in the study as the sample. Research data were collected through Occupational Stress Inventory (Osipow & Spokane, 1998), Multidimensional Fatigue Inventory (Smets, 1996), Situation Awareness Rating Technique (Taylor, 1990) and performance evaluation in flight simulation environment and analyzed using structural equation modeling method and bootstrap test in Amos-21 software. Results: The results showed that the hypothetical research model with some modifications had a good fit. The fit indices of the final model included TLI= 0.91, CFI= 0.93, IFI= 0.93, GFI= 0.93, SRMR= 0.056, RMSEA= 0.055. The results also showed that occupational stress affects cognitive performance through mediating role of mental fatigue. Situation awareness also affected cognitive performance by mediating role of mental fatigue and flight factors. Conclusions: Based on the results, it can be concluded that pilots who have less occupational stress and mental fatigue, more situation awareness of and a high level of flight factors show better cognitive performance.

Abstract Purpose: Workers in many industries (oil, gas, petrochemicals, cement, steel, glass, and textile) and even at home, offices are exposed to various noises with different frequencies causing hearing and non-hearing impairments. The present study aimed to investigate the effect of noise at different frequencies on physiological responses and cognitive functions of oil drilling industry personnel and urban gas pressure reducing station. Materials and Methods: This descriptive-analytical study was conducted in 2019 with the participation of 50 employees of oil drilling rigs (low frequency noise) and city gas pressure reducing stations (high frequency noise). Physiological parameters examined included (heart rate, systolic and diastolic blood pressure, and tympanic body temperature). The participantschr('39') cognitive functions were assessed using advanced reaction timer, continuous performance and working memory tests before, during and after the activities. Also, the relationship between variables was investigated using structural equation modeling (SEM). Results: The study results indicated that was exposed to noise at high and low frequencies, physiological responses, including heart rate, systolic and diastolic blood pressure and tympanic temperature increase, and this increase was statistically significant (p

Abstract Background and Aim: heat stress is the most common occupational risk factors and can adversely affect the health and efficiency of the individuals. Exposure to extreme heat in the workplace can cause heat-related illnesses as well as increased risk of accidents and related injuries. The previous Studies have shown that heat stress can lead to some physiological responses and affect cognitive function. But these studies have not reached a clear and definitive conclusion. There have been several studies on the effect of heat stress on heart rate and blood pressure. According to the results of the most studies, heat exposure can increases heart rate, but the results of the researches on the effect of heat exposure on blood pressure are not the same. According to the results of the most studies, heat stress can leads to decrease in cognitive performance; however, some studies have shown that cognitive performance does not change or in some cases increase under heat stress conditions. Due to the differences in the results of the previous studies in this area, further studies are needed to clarify these results. The purpose of this study was to investigate the effect of heat stress on cognitive performance, heart rate and blood pressure of the students. Materials and Methods: In this experimental study, 18 volunteer students (9 girls and 9 boys) from the school of health and safety at the Shahid Beheshti University of Medical Sciences with the mean age of 21.11 year and standard deviation of 1.71 year and body mass index of 23.23 kilogram per square meter and standard deviation of 1.44 kilogram per square meter participated. This study was conducted in the laboratory of heat and humidity control. Each participant was randomly exposed to one of the test conditions with 3 different Wet Bulb Globe Temperature. According to the factorial method, there were six different Wet Bulb Globe Temperature conditions in which the subjects were tested in one of these six states. A total of 54 experiments were performed on the subjects. Before the test, all the participants received written consent and they all became familiar with the stages of the experiment. Prior to the test, the participants completed a questionnaire of the inclusion. The criteria for entering the study included age 20-24, undergraduate education, body mass index (BMI) of 23±2 kg/m2, no cardiovascular and mental illnesses, normal heart rate and blood pressure and no drug consumption. In order to examine the mental health of the individuals, they were asked to complete the General Health Questionnaire, developed by Goldberg (1972), before the test. Those who obtained the total score of 0 to 22 were classified in the group without any symptoms or least limit and included in the study. The participants were asked to have sufficient sleep and rest and a normal diet, without coffee or caffeine, before the test. The subjects were also asked to wear simple linen or cotton clothes with light colors to take into account the effect of Clo on heat stress for all the participants. Unwillingness to continue to cooperate during the test was also considered as an exclusion criterion of the study. After selecting the samples based on inclusion criteria, other interfering factors, including noise and lighting were evaluated and controlled. The lighting equal to 450 lux and noise pressure level equal to 35dB were recorded and controlled. Participants were exposed to three different thermal conditions (Wet Bulb Globe Temperature of 29°C as lower than the exposure limit, Wet Bulb Globe Temperature of 32°C as the exposure limit for the non-acclimatized people to warm environments, and Wet Bulb Globe Temperature of 35°C as more than the exposure limit for the non-acclimatized people) for 30 minutes, and their cognitive performance was evaluated in these three thermal conditions. The relative humidity in all stages of the study was 50%. To provide different temperature conditions, two EFHA2200 model electrical fan heaters, manufactured by ARASTEH, as well as two Beurer humidifiers were used. To measure the relative humidity, the GM8910 humidifier (BENETECH Company, China) was used with a precision of ± %5, and to measure the WBGT index, the digital QUESTEMP10 WBGT meter was used with a sensitivity of about one tenth degree Celsius. All the devices were calibrated before the test. To measure the WBGT index, the device was placed at a distance of about 10 cm from the body of the participants in the waist area (0.7 m), and after about a minute, the numbers shown by the device as a WBGT indicator were read. To assess the effect of heat stress on cognitive performance of the participants, a 2018 Integrated Visual and Auditory Continuous Performance test was used and the scores of attention scales including selective attention, focused attention, divided attention, alternating attention and sustained attention were measured in both visual and auditory domains. The IVA test is a computerized test for sustained attention and response control. The participants were exposed to pseudo-randomly ordered series visual and auditory stimuli of numbers 1 and 2, and they were asked to click the mouse when they saw or heard the number 1. With an initial explanation of how to do the test, the entire test lasted 11 minutes. The IVA results were presented in six primary scales (three response control scales and three scales of attention) in the visual and auditory areas. The response control scales are as follows: (Prudence, Consistency and Stamina). The attention scales are as follows: (Vigilance, Focus and Speed). In order to investigate the effect of heat stress on physiological parameters, blood pressure and heart rate of the individuals was also measured before and after exposure to heat. To Measure the blood pressure and heart rate of the subjects, digital Blood Pressure Monitor was used. Its accuracy for measuring blood pressure was ±3 mmHg and for measuring heart rate was ±%5. SPSS software version 22 was used to analyze the results. To analyze the relationship between heat stress and heart rate, blood pressure and attention scales resulting from the Integrated Visual and Auditory Continuous Performance test, the Generalized Estimating Equations test (GEE) was used. Results: According to the results of this study, with increase in Wet Bulb Globe Temperature, the heart rate of the participants significantly increased in relative to pre-exposure conditions (79.72 beat per minutes with SD of 6.83 in Wet Bulb Globe Temperature of 22°C and 90.05 beat per minutes with SD of 8.71 in Wet Bulb Globe Temperature of 35°C, p0.05). With increasing heat stress, the mean of two scales of in auditory domain including auditory selective attention and auditory alternating attention steadily decreased, and this decrease was significant at the Wet Bulb Globe Temperature of 35°C (p 0.05). Conclusion: The results of this study showed that heat stress has a strong and significant relationship with physiological parameters such as heart rate and systolic and diastolic blood pressure. According to the results of this study, heat stress can increase the heart rate and systolic blood pressure and decrease diastolic blood pressure; so Changes in heart rate and blood pressure can act as a good indicator for the heat strain. Exposure to excessive high temperatures can reduce attention and consequently decrease cognitive performance. One of the limitations of this study was the difficulty of doing it in real work environment. Considering that in industrial and real working environment, many interfering factors such as risk factors of the work environment, family and psychological conditions of the subjects, nutrition, different work shifts and time of sleep and rest can affect the results of the study, it will be difficult to select similar samples that meet all of the requirements of this study. However, studies similar to the present study need to be carried out in industrial environments and real work conditions in order to increase the applicability of the results of study in work environments.

Abstract Background and aims: Noise is an important source of physical and psychological stress that is considered as the most important physical detrimental factor in developed and developing countries. In the United States, more than 30 million workers are exposed to dangerous noise, and 7.4 to 10.2 million industrial workers are at risk of hearing loss due to exposure to industry noise, but what is certain is that the noisy environment causes carelessness in activities. The brain becomes inconsistent in intellectual work and so on. Noise is an environmental stressors and in combination with other stressors can cause or exacerbate mental disorders and even under certain conditions can affect performance to the extent that WHO considers accidents as one of the indicators of performance decline. Recognizes noise-induced and recognizes ambient noise as a direct cause of mental disorders.Noise is the most common occupational hazard in various industries, especially petrochemicals and related companies. Noise exposure causes a wide range of the discomforts, disorders and occupational diseases and effects including focus loss, long-term memory loss, anger, increasing stress and etc. Cognitive performance such as consistent attention, comprehension, speed of reaction as well as correct information processing and correct decision making play a key role in performing many tasks .In some occupations, in order to react appropriately and in a timely manner, the person needs to process the information completely and without defects. Therefore, even temporary defects in cognitive and mental performance can lead to serious consequences in individuals, especially when an accurate and immediate response is needed. The results of various studies conducted in the oil and gas industry and related companies indicate that sometimes noise contact is outside the permissible range (85 dBA) .Basically, in the oil and petrochemical industries, a lot of noise is produced, which can be said that the main noise produced is related to the movement of fluids and related piping on the one hand, and on the other hand, the era of engines and compressors in refining operations. It is essential to maintain human health and safety of the work system at the highest possible level, and any error on the part of operators can lead to unintended and harmful consequences or accidents, or reduce the quantity and quality of products and irreparable economic losses and considering that the accuracy, speed of action and ability to perform skills by individuals; are the most important factors affecting the efficiency and increasing the productivity of human resources in improving the level of production and its quality, so evaluate the effects of different sound pressure level cognitive performance has been performed on petrochemical industry workers. Methods: This descriptive-analytical cross-sectional study was conducted in 1398 in Kavian Petrochemical Company located in South Pars region (Assaluyeh). In this study, before collecting information, the purpose of the study was explained to the participants. Demographic data collected included: age, work experience, body mass index and metabolism. Exclusion criteria included: less than one year of work experience, use of hypnotic and caffeinated substances, having any mental disorders, sleep disorders, major systemic diseases, etc. Subjects were divided into three groups (one control group and two case groups). There were 30 people in each group. In the study of the effects of sound pressure levels below the allowable limit, control room operators were selected and participants in 2 case groups were selected from site operators who were exposed to more than the allowable noise level. Metabolism of participants in three groups was determined according to ISO 8996 standard. Participants in the study had a work schedule of one week working day and one week working night. In this study, day workers who were active from 7 am to 7 pm were selected. To investigate the effect of noise on workers' cognitive performance, first the average equivalent sound level during the shift (beginning, middle and end of the shift) was measured .Since the sound pressure level is different in different parts of the workplace and the company workers normally commute in different parts of the environment, so to determine the average sound level equivalent to their exposure, the dosimeter is the most reliable method for measuring and evaluating. It is an individual encounter. The dosimetry was performed by TES-1345 dosimeter made in Taiwan, in accordance with ISO 9612 standard. Before using, the device was calibrated by a CEL110.2 calibrator made by Casella Company. In the studied units, measurements were performed using a regular grid pattern and then the cognitive performance of individuals at the beginning, middle and end of the shift was measured using CPT and N-back tests.The Continuous Performance Test (CPT) is used to measure people's attentive attention and alertness. It is a valid test that is used to find sustained attention deficit impaired performance.In the continuous performance test (CPT), 150 numbers appear at regular intervals and a stimulus is determined as the target stimulus, and the participant must press the relevant key on the computer screen as soon as possible by observing the desired numbers. The variables measured in the CPT test were commission error, omission error, and response time (milliseconds), and working memory test (N-back) is used to measure working memory of individuals, since this task includes both cognitive information retention and manipulation, it is known to be very suitable for measuring working memory performance. And repeatedly used for this purpose, in the working memory performance test (N-back), a sequence of numbers, step by step, appears randomly on the screen as a visual stimulus. . The subject should then examine whether the current stimulus presented is consistent with the N-stimulus preceded by it. The variables measured in the working memory performance test (N-back) were reaction time (milliseconds) and mean correct response. The collected data were analyzed with SPSS V.20 .Then descriptive methods (mean, standard deviation and frequency) were used to summarize the data. The normality assumption for the data was performed using the Kolmogorov-Smirnov test. The main basis of data analysis was based on analysis of variance (ANOVA). Significance level in data analysis was considered less than 0.05. Results: Comparison of the results in the Continuous Performance Test (CPT) showed that the average equivalent sound level has no effect on the commission error, but at the end of the shift the commission error is significantly affected (P=0.040).However, the average equivalent sound level has no effect on the omission error and only the omission error in the middle and end of the shift is statistically significant (P0.05) and only the correct response in the middle and end of the shift was statistically significant. The highest reaction time and the lowest mean correct response belonged to the third group who were faced with a sound pressure level of 91.83± 1.78 dBA .Accordingly, the number of correct responses of the groups that were exposed to more than the allowable noise was significantly less than the group that was exposed to less than the allowable noise .Also, the number of errors in these groups was more than that group. According to the Continuous Performance Test (CPT) and also according to the Memory Performance Test (N-Back), the sound pressure level increases the reaction time of the subjects (P

Background: Road traffic noise is one of the most common sources of environmental noise which has various effects on mental and physical health, impaired daily life function and cognitive performance. Vibration is another achievement of industrial development that is accompanied by noise in most work environments. Vibration transmitted from road surface to vehicles and drivers may interfere with activities, affect their comfort level and reduce attention. The purpose of this study was to compare the effect of independent and simultaneous exposure to traffic noise and whole body vibration on visual and auditory attention and control response of males using Integrated Visual Auditory Performance Test (IVA + PLUS). Methods: The study population included 24 male students aged 18 to 30 years old in Shahid Beheshti University of Medical Sciences who had inclusion criteria for the study. The experiments were performed in 4 steps randomly in one day for each person in the acoustic room and in total, 96 experimental runs (24 runs per step) were performed. Inclusion criteria included: Students in the age group of 18-30 years, no history of underlying diseases including respiratory problems, skin disorders, sleep and cardiovascular disorders and other health problems affecting onechr('39')s muscular and brain health, no short term illnesses during the trial (colds, diarrhea and vomiting), no history of upper limb musculoskeletal disorders, hearing loss less than dBA27, visual acuity above (7/10), no smoking addiction and drugs and alcohol, no use of hypnotic drugs and CNS attenuating drugs during the test period, not being over sensitive to sound according to Weinstein noise sensitivity questionnaire and getting a score of 22 or below in General Health Questionnaire, which reflects the health of the individuals. Exclusion criteria also included: a personchr('39')s unwillingness to continue participating because of the long studychr('39')s time and people who did not meet the above criteria. Subjects did the IVA test (data recorded including scores of total attention and response control scores) in background conditions (sound level dBA 27 and vibration acceleration zero), then they were exposed to individual and combined noise level of 55 dBA (as the permissible sound pressure level at outdoors) and the vibration acceleration of 0.65 m/s2 (as the average acceleration vibration in the Iranian vehicles). In this study, a vibration simulator was used to generate a vibration in the x, y, and z axes at different frequencies and intensities, either sinusoidal or randomly using a vibrating engine. The Italian OLI VIBRATOR MVE.440 / 2M vibrating engine was attached to the seat using a metal stand. The Ic5 inverter was used to adjust the vibration frequency and acceleration and the whole body vibration meter according to ISO 2631 was used to ensure the calibration of the vibration produced by the vibration simulator. The noise used in this study was generated by the signal software with combining the desired frequency and these computer-generated audio files were performed in the Cool edit tool software during the test. One of the features of this software is the ability to edit the sound in intensity at different frequencies, and by continuously monitoring noise in the acoustic room, the volume of the noise can be controlled at the desired frequencies. During the exposure, the intensity of noise within the individualchr('39')s hearing range, inside the acoustic room was controlled by a calibrated B&K 2238 Sound Level Meter. The IVA is an 8-minute visual and auditory continuous performance test that assesses total attention and response control scores. The task of the participant is to react when the number 1 is seen or heard and to click on the mouse once, and don’t react when the number 2 is seen or heard. The task type assigned to the participants was "simple", its physical workload was "light". Participants signed written consent form and filled demographic information form, general health questionnaire (GHQ-28), and Weinstein noise sensitivity scale. Audiometric and the E eye chart tests were done for hearing and visual acuity testing. To determine the individual and combined effect of noise and whole body vibration on attention and response control, regression analysis of repeated measures using generalized estimating equations with first order autoregressive process was used. Results: The mean (±SD) age of the participants were 23.41 ± 2.99 years. In the visual test and in the background vibration acceleration, the mean scores of attention has been increased with increasing traffic noise from 27 to 55 dBA and the response control score has been decreased (P = 0.79 and P = 0.1, respectively). At the background noise level, mean scores of attention and response control have been increased with increasing vibration acceleration from zero to 0.65 m/s2 (P = 0.49 and P = 0.59, respectively),). In combined exposure condition with noise level 55 dBA and vibration acceleration of 0.65 m/s2, the mean score of attention decreased compared to background ones (P= 0.95), and the response control score increased compared to background ones (P= 0.72). In the auditory test and in the background vibration acceleration, the mean scores of attention and response control have been increased by increasing the traffic noise from 27 to 55 dBA (P = 0.02 and P = 0.13, respectively), At the background noise level, mean scores of attention were significantly reduced by increasing the vibration acceleration from zero to 0.65 m/s2 (P =0.01). Mean scores of response control has been increased with increasing vibrational acceleration from zero to 0.65 m/s2 (P=0.74). In combined exposure condition, the mean scores of attention were significantly lower than background ones (P =0.01), and the response control score has been increased compared to the background ones (P= 0.09). Conclusion: Similar results were found regarding the combined effect of noise level 55 dBA and vibration acceleration of 0.65 m/s2 on the total level of attention and response control in visual and auditory tests. So that the simultaneous increase in noise level and vibration acceleration relative to the background condition leaded to decrease in the total score of attention in both visual and auditory dimensions. However, in the mentioned conditions, the response control score has been increased in both visual and auditory tests. It seems that the score of response control, which in some way expresses the ability to sustain attention and the reaction speed during the test, has been increased as a result of noise motivation theory and the positive short-term effects of vibration acceleration. In general, whole body vibration in low to moderate acceleration level and low level of noise may improve cognitive performance in a short time, however, definitive conclusions are subject to doing the systematic and comprehensive studies.

Background and aims: The circadian rhythm is one the most important biological rhythms that regulates the sleep-wake cycle and repeats every 24 hours roughly. This 24-hour cycle includes physiological and behavioral rhythms like sleep cycle. Any disruptions in the body’s natural rhythms can cause many problems, such as drowsiness, sleep deprivation, reduced physical activity, and mental functions. Working at unusual clocks is one of the main factors that can interfere with the circadian rhythm. It is estimated that almost 25% of employees have experienced some kind of shift around the world. Studies have showed that about 62% of these shift workers suffer from sleep disorder, which is defined as a general or partial deprivation of sleep. Various studies have also shown that in the night shift, the performance of individuals is reduced by 10-5%. If the night shifts when accompanied by sleep deprivation on the next day, the performance of people is reduced by up to 30%. There are several work shift schedules in different industries. These include fixed shift, split shift, irregular shift, rotating shift and so on. Rotating shift follows an especial speed and direction. The speed means the number of times working a particular shift before moving or rotating to a different one. Working in every morning, evening, and night shifts for two consecutive days. It is necessary to consider one or two days off between the shifts. Employees must at least eight hours free from work when the shift is changed. In some factories, there is no rest day between the shifts. It makes the workers deprive sleeping for one night. It is well known that lack of rest can effect on the human health adversely. Cognitive performance is one of the main functions affected in this situation. Memory, accuracy, and attention as well as reaction time are important cognitive functions which are affected in sleep deprivation. Memory is defined as the ability to record, remind, memorize, and retrieve information. One of the functional differences of the memory system is its differentiation into short-term and long-term memory. Short-term memory is responsible for storing information that is instantly used. Recently, short-term memory has found another definition called work memory. Working memory is actually the new and dynamic of memory, which is actively defined when it is necessary to perform a task. In the most conducted studies, this component of memory has been considered to evaluate the effects of sleep. Many laboratory and field studies have been conducted on the long-term effects of sleep deprivation on cognitive functions but a few studies have been focused on short term effects of sleep deprivation on cognitive functions. Considering the known effects of sleep on physical and cognitive performance of individuals, a study in this field is necessary to make suggestions for modifying such unusual work programs. In Iran most of workers in main industries are in a shift work. Shifts in these industries are often forward rotating. In many of these industries, people are resting for one or two nights after night shift, which makes the person adapt to this situation. However, some factory has an irregular shift work which expose workers with many problems. Therefore, this study was aimed at investigating the short-term effects of sleep deprivation due to unusual shift works on cognitive function of workers in a painting industry. Method: This cross sectional was conducted on the total of workers from painting section of an automotive industry. Considering the inclusion and exclusion criteria 80 persons were selected to the study. The mentioned criteria were alcohol consumption, psychiatric disorders and traumatic brain injury, using psychotropic medications and suffer from epilepsy disorder. Moreover, because the educational status of individuals is one of the factors affecting the cognitive function, all who entered the study had diploma. At first, the baseline and demographic data included age, working experience, quantity of sleep during the previous night shift were asked and recorded. Working shifts were rotating forward from morning to night and night to morning. In this factory, after the night shift, the morning shift began immediately without any rest. In order to investigate the effect of this irregular work shift schedule, cognitive performance was measure in two different conditions. Generally, the study was designed in two phases. Firstly, in the first day of the morning shift following the night shift people who didn’t take any rest in previous night were entered into the first phase of the study. Thus after giving a questionnaire contained some question about quality and quantity of sleep, people with the sleep duration less than two hours were selected for the rest of the study. Cognitive performance was evaluated in three different domains including working memory, selective attention and reaction time by the computerized tests. For assessing the working memory, a validated Persian test of N-Back was applied. STROOP test and Simple Reaction Time Test (SRTT) were also used to measure attention and reaction time status, respectively. In N-Back test, subjects have to react to all of the stimuli so it requires constant control and updating of the information in the working memory and has a very strong reputation for evaluating the working memory. This test has three different levels of complexity. In this study, its first level, N1, was used because studies show that its first level is more sensitive to the effects of sleep deprivation. In this test, 120 stimulants appeared on the screen in 5 minutes. At the first level, the subject had to compare each number with the preceding number and press a certain key on the keyboard. The Persian version of the Stroop computerized test was also used to evaluate the selective attention of individuals. The Stroop color test enables the individual to process related data, thoughts or actions while rejecting unrelated or inaccurate information. In this experiment, four colored circles below the color words are displayed. The person must press the color key word that may not match the color of the circle, regardless of the color displayed on the keyboard. Finally, the error rate and response time are reported as variables in this test. In SRTT, green circles appeared randomly on the screen, which the person had to press a key on the keyboard in the shortest time possible after it appeared. The reaction time was recorded in milliseconds. All tests were carried out in a quiet place where there was no noise, within beginning of morning shift until noon. One week later, the second phase of the study was performed in the afternoon shift when workers got adequate rest in the previous night. It should be noted that in this stage, people were also asked about duration of sleep in the previous night and those who had any sleep deprivation for any reason were temporarily set aside and, at an appropriate time, repeated the tests. The SPSS version 22 was used to stablish the statistical analysis. The tests used included one-way ANOVA, paired t-test and Pearson correlation analysis. Results: The results of one-way ANOVA showed that there was no significant difference between age and work experience (p-value> 0.05). The amounts of sleep duration of people with adequate rest and without any rest were 7.5± 2.5 and 3.5 ± 1 hour, respectively. The mean and standard deviation (SD) of the working memory (N-Back) in both situations, when workers had adequate rest and without any rest were 100.12 ± 5.79 and 85.23 ± 23.13, respectively. The average of obtained scores for selective attention for both situations was 2.51 ± 1. 3 and 8.27 ± 4.4, respectively. Mean and SD of the reaction time test were also 500.21 ±89 and 445.54 ± 105, respectively. Paired t-test analysis revealed that obtained scores for working memory and selective attention, when workers were in the morning shift and had sleep deprivation, were weaker than the time that they had enough sleep in the previous night (p-value< 0.05). Additionally, the level of error in the test was higher in these subjects. The reaction time was also longer in people who with adequate rest time, although there was not a significant difference between two groups. Pearsonchr('39')s analysis also revealed a strong correlation between the sleeping hours and memory scores, as well as a fairly good correlation between sleep hours and the number of errors in the attention variable (r2 = - 0.44). Conclusion: People working in the painting sections of the major automotive industry need to be in an acceptable cognitive performance due to the nature of their work. In general, unusual shift works and sleep deprivation reduce cognitive function in the memory and selective attention scopes because of inadequate rest time between shifts. It has been shown that brains forehead which is responsible for executive functions, shows a significant decrease in metabolic energy consumption in sleep deprivation. Since working memory and attention are both related to this part of the brain, therefore, they are vulnerable to sleep deprivation and change. The results of this study also showed that work in the night shift can make people fatigue, which reduces the executive and cognitive performance of individuals. Therefore, it seems to be necessary adjusting the work schedule in order to considering adequate time to rest between two shifts in unusual work systems.

Objective Individuals performance at the workplace is affected by different adopted postures. Sitting postures are mostly used during office work. Improper sitting postures may cause muscle fatigue and discomfort in the spine and also result in mental workload. Poor posture may result in human errors and delay in information processing. Previous studies have demonstrated the relationship between static sitting postures and cognitive factors such as reaction time to an auditory stimulus. Also, some recent studies have demonstrated the effect of static postures on cognitive performance. To our knowledge, none of the studies had considered the sitting and standing postures effects on cognitive performance simultaneously. The aim of this study was to evaluate cognitive performance during three different static working postures: standard sitting, standing, and self-selected sitting postures. Materials & Methods This semi-experimental design study was conducted on the twenty-nine healthy students (aged 20-30 years). The non-probability sampling method was selected. All participants provided their written informed consent. Participants with no musculoskeletal disorders, heart disease, spine surgery, and history of depression and stress were selected. Their depression status and level of stress were measured using Beck questionnaire. The study was approved by the Ethics Committee of University of Social Welfare and Rehabilitation Sciences. Subjects performed complex Stroop test and typing activity in an office-like laboratory setting at the University of Social Welfare and Rehabilitation Sciences. Stroop test lasted about 9-12 minutes, and a typing task was also designed for approximately 5 minutes for all subjects. Three random postures were selected based on common postures used in the office. The effects of the postures (standard standing, standard sitting, and self-selected sitting posture) on dependent variables such as total test duration and reaction time to congruent and incongruent stimulus, number of typing words and number of typing error were assessed with Repeated Measures ANOVA. To examine the differences between groups, the paired t-test was used. Results The results demonstrated that reaction time measure and number of typing error (accuracy) were affected by postures (P=0.001). Post hoc analysis demonstrated that reaction time was significantly different between self-selected sitting posture and standard sitting posture (P=0.001), self-selected sitting posture and standard standing posture (P=0.043), standard sitting posture and standard standing posture (P=0.001). With considering the average amount of reaction time to congruent and incongruent cases, it was observed that there is less reaction time in the standardized sitting posture (M=628.67 ms) compared to the self-selected sitting posture (M=689.41 ms) and standard standing posture (M= 675.16 ms). Also, among the three postures studied a significant difference was observed in the number of typing error words (P=0.001). The number of typing error (accuracy) was lower in this posture compared to the two other postures (M=1.58). Conclusion This study demonstrates that cognitive performance is affected by working postures. This study demonstrates that standard sitting posture is the best posture. Therefore, it is recommended that sitting posture can help in increasing cognitive performance in the workplace.

Background: Statins, inhibitors of 3-hydroxy-3-methyl glutaryl coenzyme A reductase, are widely used as medication to lower cholesterol levels in human patients. Much evidence indicates that statins can also exert neuroprotective actions. So, this study aimed at examining the effect of lovastatin on cognition deficit induced by bilateral electrical lesion of nucleus basalis magnocellularis (NBM) in the Alzheimer’s disease model in adult male rats. Materials and Methods: In this experimental study, 56 adult male wistar rats were divided into 8 groups (n=7): control (intact), NBM lesion group (which received electrically- induced lesion 0.5 mA in 3s), sham group (the electrode was impaled into the NBM with no lesion(, lovastatin groups (lesion+1, 5, 10, 20 mg/kg) and DMSO 5% group (NBM lesion +DMSO 5%). Acquisition and retention testing was done by using an eight-radial arm maze in which the patterns of arm entries were recorded for calculating working memory errors, reference memory error and latency in each group. Results: The bilateral NBM lesion resulted in significant reduction of spatial memory in acquisition and retention tests in the form of increased working and reference memory errors compared to the control group (P

Introduction: Heat stress is one of the Hazardous physical agents in the workplace, which can cause impairment of cognitive performance. The current study aimed to evaluate the effect of different levels of heat stress on attention and reaction time in a laboratory condition. Material and Method: This experimental study was done among 33 students included 17 males and 16 females. Mean age of the participants was 22.1(SD=2.3). Attention and reaction time parameters were evaluated using the continuous performance test and reaction time measurement device respectivlely, after exposure to different heat levels (22°C and 37°C). Data were analyzed using ANOVA test and SPSS 20 software. Result: The results of tests attention and reaction time showed that the average of attention percentage was decreased and the average of reaction time increased by increasing the heat level, with a statistical differences of (P˂0.001) in both cases. Attention percent in terms of exposure to 22°C temperature was significantly higher than 37°C (P˂0.001). But, reaction time was significantly higher than with the exposure to 37°C temperature than 22°C (P˂0.001). Conclusion: The results of this study showed that, heat by increasing reaction time and decreasing attention leading to an impairment in the individual’s cognitive performances. Therefore, in jobs such as control rooms and various industries that need attention, concentration and quick reaction, it is necessary to consider and optimize the heat conditions in order to increase the level of attention and decrease of reaction time.

Introduction: Low frequency sound is one of the most important sources of sound in the environment. Some individual differences such as extraversion, neuroticism, and sound sensitivity are factors that influence the effect of sound on cognitive functions. The purpose of this study was to investigate the effect of personality type (introversion/extraversion) on cognitive Performances in the presence of low frequency noise.Methods: This is an interventional study. The study population was Hamadan University of Medical Sciences students. 120 of them were selected through purposeful sampling (60 extraversion and 60 introverted) and entered the study. By simulating the real environment of each person, they were exposed to 50, 60 and 70 dB for 40 minutes. During the encounter, the cognitive Performances of the subjects were examined using the integrated visual auditory continuous performance test. Data were analyzed using SPSS20 software, independent t-test and ANOVA. Results: The results showed that low frequency noise negatively affects the components of cognitive Performances and decreases from 50 to 70 dB with increasing noise pressure (p

Introduction: driving is such a complex cognitive task that requires a high level of vigilance and response to an emergency. Anything that leads to cognitive performance degradation in the driverchr('39')s mental processing, increases crash risks. Traffic noise as one of the most destructive elements of cognitive function was examined in this study. Methods: In this study, the sample consisted of 80 patients (40 cases and 40 controls) who were students of Tehran University of medical sciences that were selected through systematic sampling and then the average sound pressure level recorded traffic noise was played for participants in the acoustics room. To Measure reaction time and error in time movement anticipation, the RT and ZBA softwares were used ,respectively. Results: The results revealed that reaction time increased significantly after exposure to traffic noise. The error time movement after exposure to traffic noise has not significant difference. Conlusions: According to the results it can be concluded that mental activities such as speed and power of information processing are affected by traffic noise and in a confrontation with traffic noise show different changes.

مقدمه: عملکردهای شناختی با افزایش سن و به مرور زمان کاهش می‌یابد که شاید به خاطر نقص عملکرد کولینرژیک در قاعده‌ی مغز جلویی باشد. با توجه به اهمیت فیزیولوژیک تأثیر سریع استروژن، این تحقیق با هدف ارزیابی اثر 17-β استرادیول بر تخریب دو طرفه‌ی هسته‌ی قاعده‌ای مگنوسلولاریس مو‌ش‌های صحرایی نر بالغ مدل بیماری آلزایمر انجام شد. روش‌ها: در این مطالعه، 40 سر موش‌ صحرایی نر بالغ نژاد ویستار (Wistar) به شش گروه هشت‌تایی تقسیم شدند. گروه شاهد (دست نخورده)، گروه تخریب Nucleus basalis of meynert (NBM) (تخریب دو طرفه‌ی هسته‌ی قاعده‌ای مگنوسلولاریس با القای جریان الکتریکی 5/0 میلی‌آمپر به مدت 3 ثانیه)، گروه شاهد تخریب (ورود الکترود به هسته‌ی NBM بدون القای جریان الکتریکی)، گروه استروژن (تخریب NBM + 45 میکروگرم بر کیلوگرم 17-β استرادیول)، گروه روغن کنجد (تخریب NBM + 200 میکرولیتر روغن کنجد). در آزمون‌های اکتساب و یادآوری دستگاه ماز شعاعی هشت بازویی، الگوهای ورود به بازوها در هر گروه برای محاسبه‌ی انتخاب‌های درست، خطاهای حافظه‌ی کارکردی، خطاهای حافظه‌ی مرجع و زمان سپری شده در نظر گرفته شد. یافته‌ها: تخریب دو طرفه‌ی هسته‌ی NBM، کاهش حافظه‌ی فضایی در آزمون اکتساب را به شکل افزایش معنی‌داری در خطای حافظه‌ی کارکردی و مرجع (001/0 > P) و همچنین کاهش این عملکردها در آزمون یادآوری (001/0 > P) را نسبت به گروه شاهد تخریب نشان داد. تزریق 17-β استرادیول (45 میکروگرم برکیلوگرم) بعد از تخریب NBM، پارامترهای خطاهای حافظه‌ی فضایی را در دو آزمون اکتساب و یادآوری نسبت به گروه شاهد تخریب بهبود بخشید (050/0 < P). نتیجه‌گیری: تخریب الکتریکی NBM می‌تواند عملکرد حافظه‌ی فضایی را کاهش دهد. استروژن‌درمانی بعد از آسیب مغزی اختلال شناختی را بهبود داد.

Background and Objective: Patients with Mild Cognitive Impairment (MCI) demonstrate inadequacy in compensatory techniques and lacking motor control while falling; hence it appears that cognitive and motor deficiencies are inter-related. The aim of this study was to investigate the progressive dual-task effects on motor performance, cognitive status and fall risk between older adults. Subjects and Methods: This study is semi experimental with pre- and post-test design. The subjects were selected from community dwelling elderly adults with mean age of 75.65 y (range, 65-90). Both groups (20 with MCI and 20 Healthy) participated in 12 weeks of intervention with progressive dual-task training, which entailed sitting, standing and transforming practices. Results: Examinations after 12 weeks showed that intervention caused improvements in cognitive status, postural control, and fall risk in both older adults with and without MCI. The MCI group experienced more positive changes in cognition, while the normal group had the most evident effects in fall risk and performance in Functional Reach (FR) test. Conclusion: This finding supports the previous results which implied the positive effects of dual-task training on cognitive variables are associated to biological variations which arise during exercise training. We also suggest that the physical benefits of progressive dual-task training (e.g. flexibility) are overriding the cognitive changes. In future research, the pathophysiology and further clinical implications should be investigated. [ABSTRACT FROM AUTHOR]

Backgrounds and Objective: The main important factors in decreasing cognitive performance are aging, proinflammatory and metabolic syndrome. The aim of this research was investigation the effect of twelve week aerobic exercise whit moderate intensity on IL-6, IL-10, and cognitive performance in 50-65 years old women with syndrome metabolic. Materials and Methods: 24 women with metabolic syndrome (MetS) voluntarily took part in the study and were divided into two groups: MetS exercise (ME), MetS control (MC). The ME group participated in an aerobic exercise training (AT) program (12 weeks), three sessions per week, each session containing three performance parts and two rest parts. Also blood samples were drawn before and after training to evaluate levels of IL-6, IL-10. Cognitive performance was measured by digit span memory test. Data were analyzed using Pearson coefficient, pried-sample T-Test, and independent samples T-Test. Results: After three months of aerobic exercise, IL-6 levels decrease while IL-10 levels and cognitive performance increased significantly (P<0.05). IL-6, IL-10, and cognitive performance in the control group were not altered after three months (P<0.05). Conclusion: These findings indicate that three months of aerobic exercise can increase IL-10 level and decrease IL-6 while ameliorating cognitive performance. [ABSTRACT FROM AUTHOR]