جستجوی مقالات مرتبط با کلیدواژه « زمان واکنش » در نشریات گروه « پزشکی »

Stress is a kind of physical or psychological exhaustion caused by real or imagined problems. Occupational stressors play a major role in influencing employees' actions by reducing focus and creating doubt. Three types of reaction time, including simple, diagnostic, and selective, are essential in the performance of various motor tasks.

This descriptive-analytic study was conducted cross-sectionally among 82 emergency personnel. Reaction time and job stress were measured using a reaction timer and the Iranian version of the HSE Job Stress Questionnaire, respectively. Data analysis was performed using SPSS-20, and a significance level of p<0.05 was considered.

The mean values for job stress, simple reaction time, diagnostic reaction time, and selective reaction time in the study population were 125.51, 310.98, 473.50, and 453.82, respectively. An independent T-test indicated that gender does not affect occupational stress and reaction time. Additionally, according to the Pearson test, a significant inverse relationship was found between job stress and diagnostic and selective reaction times, indicating that as job stress increases (or stress reduces), a reduction in reaction time is observed (p<0.05). However, there was no significant relationship found between job stress and simple reaction time.

It is recommended that in jobs requiring high reaction time and accuracy, improving job performance by reducing individual stress should be prioritized. This approach can help prevent work-related accidents, which are sometimes caused by delayed responses. Additionally, it is advisable to monitor individuals not only through physical examination but also in terms of their mental and psychological conditions.

Heat stress is the most physically harmful factor in open and closed industrial environments. It affects people's cognitive and mental functions, causes the speed of fatigue, reduces concentration and skill, and increases the amount of errors. Therefore, the current research has The Effect of Heat Stress Exposure on Visual- Auditory Performances of subjects in laboratory conditions.

This study was conducted on 32 male students of Shahid Beheshti University of Medical Sciences, aged 20 to 29, who were selected according to the condition of consent and meeting the inclusion criteria. Environmental heat stress was applied at three levels of temperature index of 22, 29, and 34 degrees Celsius, and the temperature index of 22 degrees Celsius was considered as the laboratory background condition. Then, they were studied in different laboratory conditions, including exposure to heat stress. The subjects' attention level and reaction time were evaluated using the Integrated Visual and Auditory Continues test tool. The participants completed the written consent form, demographic information form, and general health questionnaire. Also, the subjects' heart rate was recorded with a digital heart rate monitor.

This study showed that the amount of visual and auditory attention decreased significantly (p<0.001). The reaction time of people increased significantly under the influence of heat stress (p<0.001).

The results showed that exposure to heat stress are an effective factor in reaction time, attention level, and heart rate, which can reduce accuracy in doing work. Therefore, paying attention to the amount of thermal stress in working environments plays an important role in improving the speed and performance of people.

Clinical symptoms of autism spectrum disorder are diverse and include neurodevelopmental and cognitive impairments, as well as memory deficits, which are one of the most challenging areas for these individuals.

The present study aimed to develop and validate a neurocognitive rehabilitation program and evaluate its efficacy on reaction time, recognition of shape, and visual-spatial memory in high-functioning male teenagers with autism.

The study was conducted as a quasi-experimental design with pre-test and post-test measures and a one-month follow-up session. The population included male teenagers with autism attending special schools in Tehran during the academic year 2022-2023. A total of 30 participants were selected from this population using convenient random sampling and assigned to experimental and control groups. The participants received ten one-hour sessions of intervention over a period of 1.5 months, and Sina cognitive software was used in three stages: pre-test, post-test, and follow-up. Independent t-test was used to compare the change scores between the two groups, and repeated measures analysis of variance was used to examine the stability of the intervention's effectiveness.

The results showed a significant reduction in reaction time for simple reaction (t(28)=3.16, d=0.83, P=0.004) and selective reaction (t(28)=8.11, d=0.76, P<0.001) in the experimental group compared to the control group in the post-test and follow-up stages. Moreover, the experimental group showed a significant improvement in pattern recognition (t(28)=10.67, d=0.893, P<0.001) and visual-spatial memory (t(28)=10.90, d=0.884, P<0.001) compared to the control group in the post-test and follow-up stages.

Computer-based cognitive exercises are effective in improving cognitive performance and memory in individuals with autism. If these exercises are combined with sensory and motor interventions, better and more sustainable results can be achieved.

IntroductionCognitive dysfunctions may be brought about following the diseases which have destructive effects on the central nervous system. One way of studying the relationship among brain, behavior and thought, is examining and investigating the brain damaged people, among them Multiple sclerosis is one of the most prevalent diseases of CNS.Material and MethodThe aim of present study was to investigate the diagnostic value of simple and selective reaction time in discriminating patients with multiple sclerosis (MS) from normal people. For that purpose, two groups of patient with MS (n=44), a group of normal people (n=48) were selected as the control group. Their reaction time in simple and selective modes were measured by reaction timer, then demographic information of all subjects were collected and their inability was evaluated by EDSS.Mann-Withney U test and logistic regression were used to analyze the data. Following analysis of data, it was revealed that both simple (z= -2.566, p=0.011) and selective (z=6.348, p<0.001) modes of reaction time in patients with MS, were significantly more than control group. Selective reaction time was statistically able to predict health and illness (χ2= 51.067, df= 2, p<0.0001).ResultsBoth simple and selective reaction times were significantly longer in the patient group, and it was able to differentiate the MS patients from normal people.ConclusionAccording to the findings of the research, reaction time in both simple and selective modes is appropriate in differentiating the patient with MS, from normal people, and hence it is worthy to be utilized in clinical situations including clinics and neurology wards of hospitals.

There is evidence that driver distraction is one of the major causes of vehicle accidents. One of the key factors that can affect people's driving performance drastically, is texting. Therefore, the purpose of this study is to determine the effects of texting on driving functions using a driving simulator.

This study was conducted on 80 students ranging from the ages of 20 to 40 and using a class 2 simulator. To check the performance of the drivers, reaction time variables, lane lateral deviation of the car, speed control, were used in two modes of driving without texting and driving while texting. The main scenario of the study consisted of driving a distance of 20 km on a highway.

The average momentary lane lateral deviation of the car for drivers in two stages without texting and while texting, was 0.88 and 1.36 meters, respectively, which had a statistically significant difference (P<0.001). Also, the average reaction time for drivers in the two stages without texting and while texting was 1.23 and 1.52 seconds respectively, which had a statistically significant difference (P<0.001). Furthermore, the average speed for the drivers in the two stages was 35.12 and 34.04 m/s, respectively, which had a statistically significant difference (P=0.020).

It is indicated that texting while driving has a negative impact on driving performance. The results of this study have direct consequences for drivers who are involved in this type of distracting behavior while driving, therefore it is important and essential for drivers to be aware of the impact of using cell phones while driving on driving performance.

Multiple sclerosis (MS), is an inflammatory chronic disease of the central nervous system, usually starting in the most productive years of the patient’s life, and its cognitive consequence may affect on patient’s behavior, social functions, daily life, and occupation. One of the most important cognitive variables, which may be affected through MS, is reaction time. The aim of this study was to investigate the reaction time of patients with MS (SPMS and RRMS types) toward visual and auditory stimuli.

The study design was a retrospective, causal-comparative type, in which the sample was selected through an accessible and purposive sampling method from the patients who were referred to the MS center and MS institute of Isfahan, Iran. The control group was selected from the healthy patient’s family members or their relatives. A total of 159 subjects participated in this study, each group consisted of 53 subjects. The reaction time of the three groups toward the visual and auditory stimuli was measured. The instruments comprised a reaction timer and a multiple sclerosis impact scale.

The results showed that the reaction time in the patients was significantly slower than in healthy people. Furthermore, it was revealed that patients with SPMS type were slower in reaction time in comparison to RRMS patients.

The speed of information processing in patients with MS, has become slower, due to the slowing of the conduction through nerve pulses, which is due to demyelination in damaged pathways. The decrease in processing speed may lead to an inability of the patients to accomplish mental and cognitive tasks, and this deficit is finally depicted in the inability of MS patients in responding to visual and auditory stimuli.

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.

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.

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)

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.

Vibration, especially whole body vibration, is one of the most important physical harmful factors in industrial environments as well as vehicles. Exposure to whole-body vibration can cause different mental and physiological reactions in humans. This study aimed to investigate the effect of exposure to whole body vibration on the mental performances of 20-29 years old males in laboratory conditions.

In this research, 32 male students of Shahid Beheshti University of Medical Sciences with an average age of 22.19±2.6 years and a BMI of 20.23±2.21 kg/m2 participated. The acceleration of the whole body vibration was considered at three levels of low (0.53 m/s2), moderate (0.81 m/s2) and high (1.12 m/s2) according to the ISO 2631 standard at a frequency of 3-7 Hz. The mental functions of each subject were examined first in the vibration-free state and then at different vibration acceleration levels using the IVA (Integrated Visual and Auditory Continues) tool.  The heart rate of the subjects was also recorded by a digital heart rate monitor.

The results of this study showed that with increasing whole body vibration acceleration, visual and auditory attention decreased significantly (P<0.001). In addition, the heart rate and response time of the subjects significantly increased (P<0.001).

The results showed that whole body vibration is an effective factor in reaction time, mental functions and physiological parameters, which can reduce the accuracy of the work.

Thermal sensation is not a direct sense of air temperature but is related to how people feel and a sensory experience and a psychological phenomenon that can affect their performance, productivity, attitude and sense of satisfaction. The aim of this study was to determine the subjective thermal sensation and its relationship with stress, anxiety, depression and students' cognitive function.

This study was descriptive-analytical that was performed on 167 male students of Isfahan University of Medical Sciences. Students' subjective thermal sensation was measured on a seven-point scale and ambient temperature and humidity were measured in each student's room. The DASS-42 questionnaire was used to measure stress and anxiety and the "Reaction Timer" device was used to measure the cognitive function. The collected data were analyzed by SPSS software version 20.

Students' stress, anxiety and depression were 40%, 47.3% and 41.3%, respectively. The mean temperature of the dormitory was 20.326 ° C, the mean relative humidity was 56.78% and the subjective thermal sensation of 29.9% the students were neutral from the ambient temperature. There was a significant relationship between students' subjective thermal sensation and stress, anxiety and mean diagnostic reaction time, color selection, sound selection, number of errors in the diagnostic section and sound selection.

Students' subjective sensation of ambient temperature was obtained as a very important and influential factor because in addition to affecting stress and anxiety, it also had a significant effect on their time of diagnostic reaction and selection.

One of the most critical issues in military environments is the reaction time (RT) to creative problems solving (CPS) and making decisions in this regard. One of the factors influencing the reaction time is inducing negative and positive effects. Besides, the moderating role of problem-solving synchronous variables can overshadow the interactive effect on RT.

The present study aimed to to evaluate the effect of positive and negative affect priming on the RT of CPS.

The method used for the study incsluded a pre-test, post-test experimental study on a control group; which was conducted in two stages within a four-day interval in 2019-20. All personnel working at military-medical universities participated in the study, from which 24 people were selected for an experimental study by convenience sampling method. After completing the feature’s problem-solving checklist and Remote Associates Test (RAT), in the second stage of the experiment, the research units were randomly divided into three groups of positive, negative, and neutral emotion induction. For data analysis, the mixed intra-intergroup factor analysis was used. Finally, the data were analyzed using SPSS-26 at a significance level of 0.05.

In the present study, only the hypothesis of the difference between Reaction times to the CPS test of RAT in the pre-test and post-test stages was confirmed in the three groups of positive, negative and neutral induction (F = 3.58, α <0.05 and n =24).

The results showed a significant difference between the RT to the CPS test of RAT in the pre and post-test stages in three groups of positive, negative, and neutral induction. Conclusions showed that emotional training could help RT to CPS. Thus, it is suggested that this training be placed on the agenda, especially in the military.

Absent-mindedness of drivers is one of the important cause of traffic crashes. Nowadays using of mobile phones during driving have been spread increasingly and this can disturb the attention of drivers and affect the driving performances. This study aimed to determine the effect of reading and texting of message on driving performance and mental workload of young drivers.

40 young drivers (20 males & 20 females) with the average age of 25 years were studied in a driving simulator. The scenario was driving in middle line of a three-lined highway and responsions to visual stimulus of a Peripheral Detection Task. Drivers were obligated to drive in this highway with two conditions, one in usual condition and one in condition that they were busy with receiving, reading and texting the short messages. The lateral deviation of vehicle and PDT reaction time were used to record the driving performances. And the Integrated Workload Scale was used at the end of each trial for measuring of mental workload.

The average amount of lateral deviation of vehicle. Reaction time and IWS were 26.68 cm, 502.13 ms and 2.02 respectively in usual driving trial, And were 53.04 cm, 652.12 ms and 6 respectively in driving trial with reading and texting the messages. The difference amounts of lateral deviation of vehicle, reaction time and IWS variables were statistically significant (P-value=0.000) based on paired-samples t test and Wilcoxon test in usual and with reading-texting driving trials. Moreover no statistically significant differences were seen in amounts of lateral deviation, reaction time and IWS between males and females.

This study showed that the reading and texting the short message during driving can cause both significant decrease of driving performances and increase of mental workload. Accordingly more attention to consequences of using mobile phone during driving is necessary.

Occupational noise is one of the most important causes of occupational accidents and general human error. In addition to being one of the leading causes of hearing loss and tinnitus, it is one of the most effective extrinsic factors affecting brain processing mechanisms. The human response to sound and wave explosions and changes in air pressure is a major concern in the mining. Explosive is used to break the rock and this process is referred to as an integral part of the mining process. However, this cheap method of rock breakage has inherent disadvantages and that too concerning the environment and human safety. Blasting in opencast mines is characterized by the use of large masses of explosives for a single blast. Blasting workers likewise inhabitants in a war zone are continuously exposed to explosions. It is, however, difficult to gauge the effectiveness of certain phenomenon. Physiological response to blast which is particularly transient was evaluated considering ears as the most vulnerable organs. From the survey, it is concluded that ear responses are dependent not only on the pressure but also on impulse and body orientation. It is a fact that the nature and duration of normally generated vibrations are different from that generated by a blast. Moreover, mining blasts are accompanied by higher levels of noise. Under such circumstances, whether vibration standards should be generally applied to blasting in mines is doubtful especially when the mild traumatic is observed in some cases. Almost all studies investigating the effect of the explosion on soldiers’ brain confirmed that soldiers suffer from brain injury resulted in an explosion and sound waves. They give a detailed account of community response to military explosions  but there are very few studies relating to this issue which are existing on a direct effect on physiology in general and the brain in particular due to the mining explosion and air-overpressure. The idea of the study is to ascertain any changes in the human brain due to the immediate response in and around mines. This data would be used to predict the effect of the direct impetus on human physiology and the response thereof. In the present study, the brain responses of blasting workers personnel and individuals exposed to explosive noise were investigated. 

There are some constraints for the tests. (1) Sound conditions can be kept constant only in the test, as there is a significant variation in different parameters involved in the real environment. (2) There is just one EEG device available for recording responses of one person at one time. (3) It is difficult to carry and operate the equipment at places where the actual one is taking place. The experiment we present in this paper compared the intensity of participantschr('39') brain responses to acoustic stimuli, an intense burst typically used in the literature. This sound is similar characteristics in terms of duration and intensity that is produced in the real-world by explosions. Due to the complexity of the signal processing and signal processing, this study is an interventional study conducted on five university staff, as a representative of a community that has never been exposed to blast waves and five blasting workers working in different mines. The electroencephalogram (EEG) has great potential for continuous and quantitative human state measurement. EEG is the recording of the electrical signal along the scalp produced by the action of neurons within the brain, which can be measured using electrodes attached to the scalp. The activation of a central nervous system is thus manifested in the EEG signal. Keeping in view the limited available resources and complex analysis of EEG signals, tests are not at a large scale designed to generate data bank. All participants in the experiment ranged in age from 32 to 42 years (mean: 37 years, STD: 1.5 years) and had general physical health. This study was approved by the Institutional Board Review (IRB) of the Shahrood University of Technology, corrective exercise, and rehabilitation laboratory (CRL) according to the approved protocol. Acoustic characteristics and effects of tinnitus were asked through history taking and a brief cognitive status examination was performed for all subjects. For this purpose, brain waves recorded as brain signals (EEGs) were used. Routine EEG signals recorded for 30 s. The EEG signal capture cap was eight-channel, and the channels were positioned so that different subjectschr('39') senses, including motor, speech, auditory, visual, and involuntary, were examined. Eight electrodes were selected from Fp1, Fp2, C3, C4, T3, T4, O1, O2 placement on the scalp. A1 and A2 (ear or mastoid electrodes), which are reference and ground electrodes were also connected. The experiment was designed so that the signals were recorded when the explosion sound was broadcasted suddenly without pre-awareness.Wavelet decompositions were used to investigate how different brain lobes response to explosion sound and to demonstrate differences among responses in different groups of subjects, i.e. surface blasting workers, staff, and miners. A wavelet is a mathematical function used to divide a given function or continuous-time signal into different scale components. Usually one can assign a frequency range to each scale component. Each scale component can then be studied with a resolution that matches its scale. It should be mentioned that in each level of wavelet decomposition, signal divides into two sections: low-frequency band or approximation, and high-frequency band or details; each contains a half frequency band of the signal. 

Different frequency bands of EEG signals are representative of the cognized brain’s behavior. The investigation included an application of time–frequency based method for measuring electroencephalogram (EEG) phase synchronization. The sampling frequency was set to 500 Hz by the hardware although it is higher than what is needed in this project.EEG signals can be highly contaminated by both extrinsic and intrinsic artifacts that obscure the signal of interest. Extrinsic artifacts are the noises generated mostly from an external source rather than human body physiology such as movement artifacts, environmental noise, and electrical wiring noise in the EEG sensor. To address these issues, the authors successfully tested signal processing framework to acquire high quality EEG signals. After recording the brain signal and the time of the voice transmission in the experiments, the study showed that two superior properties of the signals had to be extracted.For each subject and each electrode, one feature was gathered. Mentioned features gathered for tests that explosion sound played. It should be mentioned that in some cases feature extraction was impossible because there was not any detectable variability associated with Delta band of the signal, during explosion sound playing. Based on this study, we hypothesized that alterations in the spectral power of the EEG during the presentation of auditory stimuli compared to the rest conditions would differ between individuals with and without experience in blasting works. We analyzed power values in theta, alpha, and beta frequency bands, and tested possible differences between groups in each of the three frequency bands. In all other experiments, reaction duration times of blasting workers and staff were the same. The gradient and timing of the signal variability were monitored following the sound transmission. The reactions of university personnel and blasting workers in some channels of signal reception are similar and in others quite different. In some other channels and senses, the response of non-worker to the sound of the explosion was that the signal level decreased and their motor and auditory consciousness levels decreased, although this was vice versa for blasting workers personnel.  

How job habits influence humans’ behavior? This is a regular question that has investigated frequently. The goal of this paper was to study the behavior of blasting workers, emphasizing their brain signals. Staff were representative of common humanity, do not associated with the explosive issues. Using this algorithm, abnormal features of brain electrical activity were detected. In some cases, workerschr('39') EEG signal levels increase, unlike normal people, after hearing the sound of explosions, indicating increased levels of motor, speech, and visual awareness. However, from the perspective of auditory and involuntary senses, no significant difference was observed between two groups.In some cases there is no effect on the functioning of the brain and physiological response is not observed within the limited range of observations. As a result, no matter they know what will happen, they have gone to be panic when they heard explosion sound. In terms of reaction time to the sound of the explosion, in many cases there was no significant difference between them, except in the motor and speech senses that the response of ordinary people was far faster than the workers. The validity of the EEG-based measurement was examined through a comparison with levels obtained from workers’ samples, which has been accepted as a reliable physical measure of reactions. The results demonstrate the applicability of an EEG signal on measuring workers’ reactions. Particularly in the future works remain crucial to understanding workers’ states. This study can contribute to the knowledge of an in-depth understanding of reactions in the mining field. It shall provide a tool to continuously measure workers’ performance while they are working with explosive material in the mining.

In humans, the reaction time limit is associated with several factors. It includes the time that takes to stimulate the sensory member, the stimulus effect is transmitted to the brain, then is perceived and the decision is made; consequently, the command resulting from the decision of the brain is sent from the brain to the functional member, and the member operates. Failure to respond at the right time may result in human error and the occurrence of incoming incidents. There are important factors that affect the reaction time. Attention is one of the important factors affecting the speed of the reaction. Selective attention and correct perception of several stimuli among the other stimuli is one of the effective factors in promoting productivity and safety. Additionally, various environmental factors may be effective in determining selective attention, increasing the number of errors and the human response time in detecting triggers. Environmental lighting is one of the factors affecting the processing mechanisms of the brain. In the design of indoor and outdoor lighting systems, the quality parameters of the lighting system are usually less considered. Color temperature is one of the most important qualitative parameters of light, which is measured by the Kelvin unit and is an indicator for the brightness and color of the light. The aim of this study was to investigate the effect of color of light temperature on selective attention, error rate and reaction time.

This research is an interventional and laboratory study in order to determine the effect of the color of light temperature on human error, selective attention, and reaction time of students in Tarbiat Modares University (TMU) of Tehran during the fall of 2018. All students were in the same age range. The inclusion criteria for the study were; not having any eye-related diseases, such as diminished vision and subtlety, and mental-psychiatric disorders. On the day before performing the test, individuals were urged to have enough sleep and rest, to adhere to a regular diet, and to avoid taking medicines, coffee and caffeinated drinks. In this interventional study, 92 students (36 female and 56 male) from Tarbiat Modarres University of Tehran with an average age of 28.33 years were recruited as subjects. The measurements and tests related to selective attention and reaction time of individuals were performed in 4 locations with an equal lighting system and different color temperatures (3500, 4000, 5000, or 6500 degrees Kelvin). In the first stage of the study, in order to determine the effect of the color of light temperature on the studied parameters, the participants were randomly divided into four groups with 24 subjects in each group. Before the main test was being performed, the subjects were kept in rooms adjusted to a brightness of 3500° K to rest for at least 5 minutes in order to be adapted to the situation, and then, in the same conditions, to become familiar with the test method they were studied with the Stroup software. In the second step, each group was placed in a separate room where the levels of brightness had been designed with one of the lighting systems to yield a color temperature of 3500, 4000, 5000, and 6500° K. Cognitive performance tests including reaction time, accuracy and selective attention were measured using Stroop tests. Measurement of interference score and interruption time, which are indicators of selective attention, were calculated by measuring the difference in the error rate and the reaction time in detecting incongruent and consonant words. Stroop test was used to determine the reaction time, error and other parameters. This test consists of two parts; the practice and the main test, each of which has 3 stages. The first step is to name the color in which circular shapes appears in green, blue and red colors and the participant, upon viewing the image, applies pressure on keyboard buttons which are labeled with colors corresponding to the ones on the screen. The second step is to name the word which appears in a white box. The names of the colors appear, and as soon as the correct word is recognized, the person being tested should press the color word associated to the word on the keyboard. The third step, which is the main stage of the test, is a non-consistent word (red-green-blue) shown randomly and sequentially on the monitor's screen. The subject must only press the keyboard button with the same color, only emphasizing the color and regardless of its connotation. In this test, 48 matching colored words (the color of the word is identical with the meaning of the word; red, yellow, green and blue) and 48 non-consistent colored words (the color of the word is not the same as the word meaning; for example, the blue word shown in red). The time lap between the stimulants was 800 milliseconds and the duration of each of them was 2000 milliseconds. The subject's task was to select the correct color only. Finally, the data were analyzed using SPSS software.

Based on the results of this study, the highest mean of correct selection (474.49 ± 10.65) and the lowest mean of the correct ones (654.49 ± 11.77) were assigned to the color temperature of 6500 and 3500 ° K, respectively. Also, the highest mean, the error (15.65 ± 9.77) and the lowest mean error (10.94 ± 9.4) were reported at a color temperature of 3500 and 6500 ° K, respectively. According to the results of this study, with an increase in the level of color temperature from 3500 to 5000° Kelvin, the number of questions that were not responded decreased. Likewise, the number of unanswered questions for the color temperature of 6500 °K slightly increased compared to the color temperature of 5000 and 4000 °K. The results also indicated that, with an increase in color temperature from 3500 to 6500 °K, the reaction time to visual stimuli also decreased. The highest interference score was in the light color temperature of 3500 °K which suggests that the number of faults in subjects in naming inconsistent words relative to consonant words at a color temperature of 3500° K was high compared to the other color temperatures. Also, according to Fig. 3, the maximum interference time at light color temperature is 6500 ° K. This suggests that the performance time of the subjects in naming incoherent words relative to consonants at a color temperature of 6,500° K compared to other color temperatures was more significant. Although the average response time under lighting condition with color temperature of 6500° K (718.95 ± 65.33) was less than the color temperature of 3500° K (728.58 ± 43.48), according to the results of the study, with a decrease in color temperature, the increase in mean response time was observed, but this difference was not significant (p <0.05). In the present study, we compared the mean of the studied variables (interference score, interference time, correct number, number of errors, unanswered items and response time) among classified groups tested under different lighting conditions with color temperatures (3000, 4000, 5000, and 6500 degrees Kelvin). One-way ANOVA was used for data analysis. Based on the results of Tukey's post-test, the mean of correct responses under lighting conditions with a color temperature of 6,500 ° K was significantly higher than the other color temperatures, and the average for the number of correct responses at the color temperature of 5000 was significantly higher than 3500 and 4000° K (p <0.05). The average light error rate with a color temperature of 6500 ° K was significantly lower than the mean error at color temperature of 3500 and 4000 ° K, and also the average error under lighting condition with a color temperature of 5000 K was significantly lower than 3500 and 4000 ° K. 0> p). Also, based on independent t-test (Table 2), there was a significant relationship between subjects’ gender and variables such as interference score, interruption time and number of unanswered questions. For all of these three variables (interference score, interruption time and number of unanswered questions) mean in men was significantly lower than women (p <0.05). Based on subjects’ gender, the average response time under different color temperatures showed that the response time (or reaction time) of female students under lighting conditions with 3000 and 5,000 ° K was higher than that of male students, while under lighting conditions with 4000 and 6500° K the response time of male students was higher than that of female students. Although the average response time under different color temperatures was different between male and female subjects, based on the results from independent t-test, such difference was not significant.

  In general, the results of the study showed that when subjects are exposed to a light color temperature of 6,500 ° K, the number of correct responses by them is higher than those exposed to other color temperatures, and with increasing the color temperature of the light source the number of correct answers increases. Also, according to the results of this study, the levels of error decrease by increasing color temperature of light source. Based on the results of this study, it is suggested to make use of light sources with a color temperature of 6,500 ° K in designing the lighting system of the places where human reaction time and error are of great importance. Accordingly, it is recommended to repeat this study in other demographic groups, as well as taking into account the qualitative parameters of the lighting system in addition to its quantitative parameters.

Today, physical activity as an important topic in physiology has attracted the attention of many researchers. The reaction time (simple, diagnostic and selective) which depends on the time of stimulation of sensory receptors, is an important factor in many movement functions. In this study, the authors attempted to evaluate the relation between physical activity and reaction time in adults.

This cross-sectional study was carried out on 82 male administrative staff using simple random sampling. The Iranian version of the International Physical Activity Questionnaire (IPAQ) and a Reaction Timer were used to determine physical activity and reaction time, respectively. Data analysis was carried out by SPSS 20 and Pearson correlation coefficient.

There was a significant relation between reaction times and physical activity with age (P<0.05), while there was no significant relation between selective reaction time and physical activity with work experience. Also, there was a significant correlation between simple reaction time and physical activity with body mass index (BMI) (P<0.05), but no significant correlation was found between diagnostic and selective reaction time with BMI. Moreover, a significant relation was found between the types of reaction times and physical activity (P<0.05).

According to the results, by increased physical activity the reaction time decreases. So, for employees whose jobs require rapid reaction and high precision, increasing physical activity for reducing the reaction time, and ultimately improving the job performance is recommended.

Others’ decision could constantly affect our decisions. There are numerous studies which revealed this effect properly. The social influence could affect most of the decision parameters, especially the confidence.  Recently, an interesting study showed that participants tend to match their confidence to each other while they preserve their decision accuracy in a group decision making task. Since the decision accuracy is not able to explain this effect, the main question is which decision parameter is changing in a way which could be resulted in changing in the confidence and ultimately the confidence matching. 

In order to answer this question, ten subjects attended into a Psycho-Physic study with two separate sessions; Isolated and Social. In both situations, the participants were required to determine the direction of the presented motion dots and report their decision and confidence simultaneously. In the social situation, subjects were paired with four computer-generated partners, which had been created based on the data from the isolated session. The joint decisions were determined by the decision of either partner which had higher confidence. In this session, confidence and decision of the partner were represented to the participant. 

The results indicated the subjects not only try to match their confidence to their partners, but also reported higher confidence in comparison with the isolated situation. We observed although the confidence matching did not affect the decision accuracy, however, the reaction time varied significantly in both sessions. 

 This study reveals the role of reaction time in changing the confidence and consequently the confidence matching. This study once again emphasis on the reverse correlation of the reaction time and confidence even in a group decision making task.

Colors have a great influence on the state of mind and psyche of the human being, and since humans are in close relation to the colors, the colors are very important. Colors play an active and effective role in everyday life. Therefore, they are the most important visual elements that have emotional and psychological burden. Colors allow people to understand the environment, acquire information and orientate and interact more with the environment. One of main factors affecting the success rate in computer games is the short enough reaction time to the stimulus. Therefore, the purpose of this study was to compare the reaction time in young people to different tonalities of the four main colors in psychology.

The sample consisted of 60 female students from Tabriz Islamic Art University, faculty of multimedia, who volunteered to participate in the study. Reaction times to different colors were measured in 20 randomized trials with five different tonalities of the four main psychology colors (blue, green, yellow, and red). Data analysis was performed by repeated measures ANOVA and Tukey post hoc test.

The least mean color reaction time was recorded for blue, which was significantly different from other colors (P (0.002). In general, the mean color recognition time between females was reported longer than males, and this difference was not statistically significant.

The reaction time in young people was the least for blue and the most for yellow. Therefore, using blue in danger signs may causes the viewer to react faster and reduce the risk of injury

Recently, Transcranial Direct Current Stimulation (tDCS) has been considered by researchers to improve various processes. The aim of this study was to investigate the effect of tDCS on reaction time in veterans and athletes with disabilities.

This semi-experimental study with pre-test post-test design was conducted in 2018 among all veterans and athletes with disabilities, who were members of Veterans and disabled board of Shiraz. 24 veterans and disabled persons of Shiraz athletes were selected by available sampling and allocated to experimental and artificial stimulation (sham) groups. Acquisition stage was held during 3 sessions. In the experimental group, an anode electrode was placed on the C4 and the cathode electrode was placed in the FP1. The stimulation rate was 1.5 milliamps in 20 minutes. In the sham groups, the anode and cathode electrode were placed on the C4 and FP1 points, but the stimulation was discontinued after 30 seconds. After the last session, a post-test was performed. Data analysis was performed by SPSS 22, using independent t-test and Multivariable analysis of covariance.

In the post-test, there was a significant difference between the experimental group and the sham at the simple reaction time and choice reaction time and the performance of the experimental group was better than the sham group (p=0.0001).

tDCS can improve the simple and choice reaction time in veterans and athletes with disabilities.

Road traffic accident annually lead to the death of 1.2 million people and also the disability of some 50 million people in the world. Iran is one of the countries with the highest rates of road accidents in the world. According to the annual statistics by the Iranian Legal Medicine Organization, 15,932 people have lost their lives in road traffic accidents in 1395 sh. According to figures in this report, over 75% of road deaths occur among men. Driving and guiding a vehicle is required to assign different levels of attention. In this regard, also can be pointed to the role of the mental workload. Mental workload known as a requirement that a duty impose on the available mental and cognitive resources of people. Mental workload is too high or too low can lead to incomplete understanding, inadequate attention and information processing to be inappropriate. A variety of factors can be effect on individuals driving performance and their mental workload such as age, gender, driving character and fatigue. According to studies, mistakes that can lead to accidents, in many cases, are the result of high mental workloads. Measurement of mental workload while driving can reflect the cognitive needs imposed on the driver. Various behavioral, self-reporting and physiological methods have been successfully used so far in order to measure the mental workload. One of the best ways to measure the mental workload is the evaluation of the individuals' reaction time. Reaction time is the time interval between the emergence of a stimulus and the individual's response. Driver’s gender is one of the possible effective factors that can affect driving performance. This study aimed to assess the effect of gender on young drivers' mental workload and driving performances using a driving simulator. This cross-sectional study was conducted on 40 young drivers (20-29 years) including 20 women and 20 men in Tehran at 2017. The inclusion criteria for the study were aged 20 to 29 years, filling informed consent to participate in the study, sleeping enough for 8 hours at night before the test, having at least two years of driving experience, driving at least once In the week, lack of driving experience with the driving simulator, having adequate or improved vision for the eyes, or for each eye, did not use psychotropic drugs. Exclusion criteria were included the request of the participants to leave the study, having signs of discomfort caused by the simulator, expressing a physical discomfort after the start of the test for any reason. The driving simulator used in this study is a half-body Pride made by the specialists of the virtual reality group of Khajeh Nasir Tusi Industrial University. The simulator has a computer and graphics card and software tools for simulating intra-city and inter-city roads, freeways, night driving, and driving in snowy, rainy, and foggy conditions. The drivers' performances were evaluated using the PDT reaction time and vehicle lateral deviation variables under two conditions: driving with and without mental calculations. The PDT reaction time test is one of the most common and suitable methods for assessing the performance of drivers and the response time of mental workload in simulator studies. Its validity and reliability have been confirmed in various studies. The Rating Scale Mental Effort (RSME) and the Integrated Workload Scale (IWS) self-report scales were used to estimate the individuals' workload. The main scenario of the study included driving a distance of 20 km on a highway. The mean lateral deviation obtained for female and male drivers was 0.55 and 0.51 m respectively, in the driving phase without mental calculations. Moreover in this phase the mean reaction time was 482 ms for females and 450 ms for males. In the driving phase with mental calculation, the mean lateral deviation obtained for female and male drivers was 0.67 and 0.62 m and mean reaction time for females and males was 606 ms and 569 ms, respectively. Based on the RSME and the IWS scales, women perceived more mental workload than men. For most variables of the study, however, the difference between male and female values was not significant based on the independent t-test (P-value> 0.05). Also, performing mental calculations while driving caused a significant increase (P-value = 0.05) in the values of the vehicle's lateral deviation, the drivers' reaction time, and the RSME and the IWS scales. Although there were no statistically significant differences in the study variables between males and females; the mean value of the lateral deviation for women was slightly higher than men, and their driving performance was slightly weaker than men. More lateral deviation of the vehicle should be considered in the process of doing mental calculation, because the high lateral deflection, especially automotive deviation to the left can be dangerous and even fatal accidents.

Originally, children recognize other people’s emotional expressions through an emotional transmission process that is approximately automatic. Happiness, sadness, fear and anger are some of the main internal emotions which can be directly perceived by facial expressions. Children’s reaction to the emotions demonstrate their ability to recognize and interpret them. Researches evaluating Deficit in emotional recognition of autistic children leads to conflicting results. The aim of this study is to compare recognition of six basic facial expressions and reaction times in children with and without autism spectrum disorder. For this purpose, utilizing a comparative research design, 20 children with autism spectrum disorder - selected by the use of convenience sampling method- were compared with 20 typically developing age-matched control subjects in facial emotional recognition and reaction time. Multivariate Covariance Analysis results showed significant differences between two groups in reaction time and recognition of emotions. It was revealed that performance of autistic children in facial emotion recognition was slower and less accurate than normal children. In this study, it is confirmed that children with autism spectrum disorder have a deficit in recognizing emotional expression in faces.

The most important performance of a hand when performing a task is to grip and apply force to do manual work. Grip and pinch strength are the most important factors affecting the performance of hand.The reaction time is the time interval between the stimulus presentation and the emergence of the response.Considering the high prevalence of musculoskeletal disorders due to the disproportion of work with the worker and the engagement of a large number of workers in activities that require gripping, we decided to study the relationship between reaction time, age, gender and body mass index and their influence on grip and pinch strength. This cross-sectional study was performed on 60 public affairs staff of Isfahan School of Health by using simple random sampling. To determine reaction time and grip and pinch strength, respectively, reaction timer, dynamometer and pinch gauge were used. Finally, data analysis was done using SPSS 20 software, Pearson correlation coefficient and Spearman correlation coefficient were used and P < 0.05 was considered as meaningful. The findings of the study indicate that there is a reverse relationship between simple reaction time and gripand pinch strength in both hands (P < 0.05) and discriminative reaction time with grip (P = 0.047) and pinch (P = 0.03) strength in right hand. There was also no relationship observed between discriminative reaction time and grip (P = 0.10) and pinch (P = 0.07) strength in left hand and there was no relationship between choice reaction time with grip and pinch strength in both hands (P > 0.05). Also, with the increase in body mass index, the left hand grip strength (P = 0.049) and left (P = 0.02) and right (P = 0.01) hand pinch strength have increased. The mean force of grip and pinch strength was significantly higher in males than in females in both left and right hands (P < 0.001), but there was no significant relationship between age and grip and pinch strength in both hands (P > 0.05). According to the results, in occupations that require high grip and pinch strength it is preferable to use men and people with a high percentage of attention to prevent WMSDs.