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Showing 6 results for Attention

M. Naserpour, M. J. Jafari, M. R. Monazzam, H. R. Pouragha Shahneshin, M. Saremi, S. Jam Bar Sang,
Volume 4, Issue 1 (5-2014)
Abstract

Introduction: In the most industrial environment, workers are exposed to noise everyday. Exposure to this physical hazardous agent can cause immediate as well as delayed adverse effects. Cognitive performance decrement is one of the adverse effects of noise exposure which its main consequences is occupational accidents. This study attempted examine the effect of exposure to different levels of noise with harmonic indices of neutral, treble and bass on the cognitive performance.

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Material and Method: In this analytical-descriptive study, the cognitive tests were performed by 33 students, aged 23-35 years. During the tests, participants were exposed to three type of noise including neutral, treble and bass at 4 different levels of 45, 75, 85 and 95 decibels. In order to assess students cognitive performance, continuous performance test (CTP) software was employed, which investigated attrition and reaction time.

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Result: The results of this study revealed that exposure to neutral noises with Noise Harmonic Index (NHI) of +3dB at the frequency of 1000 Hz, the maximum percentage of attention (99.88 %) was belonged to Sound Pressure Level (SPL) of 95 decibels. Maximum percentage of attention due to exposure to the treble noise with NIH -105 dB at the noise frequency of 8000 Hz (100%) and bass noise with NIH of 407 dB at the frequency of 500 Hz (99.92%) were belonged to the SPL of 95 and 85 dBA, respectively. Moreover, the result showed that the effect of bass noise with NIH of 4.5 dB and frequency of 500 Hz on reduction of attention were more than treble noise with NIH of -105 dB and frequency of 8000 Hz. Under exposure to neutral noise with NIH of 3 dB and frequency of 1000 Hz, the longest reaction time (2.594 Second) was observed at the SPL of 85 dBA. The longest reaction time for treble noise with NIH of -105 dB and frequency of 8000 Hz (2.786 Second) and for the bass noises with NIH of 4.5 dB and frequency of 500 Hz (2.594 Second) were also belonged to the SPL of 85 and 75 dBA, respectively.

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Conclusion: The results showed that bass noises (frequency of 500 Hz) increased reaction time, in comparison with treble noises (frequency of 8000 Hz).


F. Golbabaei, A. Mazloumi, S. Mamhood Khani, Z. Kazemi, M. Hosseini, M. Abbasinia, S. Fahang Dehghan,
Volume 5, Issue 1 (4-2015)
Abstract

Introduction: Working in hot and inappropriate climate condition is one of the most common problems of occupational health which can lead to heat induced diseases and even death. Heat stress may impair the cognitive processes involved in decision-making and converting simple tasks to complex ones. The aim of present study was to assess selective attention and reaction time among workers in a casting unit of a car manufacturing industry and to investigate the effects of heat stress on mentioned variables.

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Material and Method: In this retrospective cohort study 70 workers from a hot industry were selected in two of exposed and control groups. First, demographic questionnaire was completed for each of the participants and noise and light were measured as the likely confounding factors. Stroop test 1, 2, and 3 were done before and during the work in order to determine the effects of heat on selective attention and reaction time. Besides,WBGT were measured at the ankle, waist, and head levels. Data were analyzed using SPSS software, version 18.

Result.: WBGT measurements showed that the mean WBGT were 33 and 16.7 for the exposed and not exposed groups, respectively. Moreover, no significant relationships were observed between test duration, reaction time, and number of errors in Stroop tests 1 and 2 and the level of heat (P-value<0.0001). However, the mentioned variables had a significant positive correlation with Stroop test 3. Additionally, for exposed group variables of test duration, reaction time, and number of errors in Stroop 3 were significantly higher than those of control group.

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Conclusion: According to the findings in present study, heat stress causes an increase in reaction time and a decrease in selective attention. Thus, heat can be assumed as a stressor in hot work environments and the heat should be taken into account while design of job and tasks which needed selective attention or reaction time.


Zohreh Mohebian, Habibollah Dehghan, Ehsanollah Habibi,
Volume 7, Issue 3 (9-2017)
Abstract

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.


Soheil Saadat, Iraj Alimohammadi, Mojgan Karbakhsh, Hassan Ashayeri, Farideh Sadeghian, Shahrbanoo Goli, Mahsa Fayaz,
Volume 8, Issue 2 (6-2018)
Abstract

Introduction: Impairment of alertness, attention and performance associated with sleepiness and fatigue in nurses occur in night and long-term shifts that in the end of night shift reach to the maximum level can lead to traffic accidents when they returning home. The purpose of this study was to determine the effect of night shift on psychomotor abilities of driving in nurses after shiftwork.
 

Material and Method: A cohort study was carried out on 23 night shift and 24 day shift female nurses aged 20 to 40 at Sina Hospital in Tehran city, using the Vienna Test System (VTS). The concentration and selective attention, reaction time, pheriperal perception, and coordination before and after night and day shifts were measured. A multiple linear regression model and Backward stepwise selection method was used for analyses.
 

Result: In the concentration and selective attention test, sum hits  (p = 0.038) and in the visual perception test , divided attention (p =0.006) and visual field (p =0.019), and in the  reaction time test the mean motor time  (p =0.034) showed a significant adverse relationship with working in night shift, but the visomotor coordination variables did not show any significant correlation.
 

Conclusion: The results showed that the concentration and selective attention, peripheral perception, and reaction time of psychomotor ability of driving were significantly adversely impaired in nurses after night shift. These results in evidence of the mechanism of increasing traffic accidents after night shift among nurses added to the previous studies in this subject.


Farough Mohammadian, Mohsen Fallahati, Milad Abbasi, Mojtaba Zokaei,
Volume 13, Issue 3 (9-2023)
Abstract

Introduction: Many industries have multiple factors harmful to health, leading to simultaneous exposure of these factors to each other. Noise is one of the most common physical parameters in the work environment. On the other hand, heat is also increasing due to various energy processes in industries. Therefore, this study was conducted with the aim of determining changes in physiological parameters and visual-auditory attention in acute exposure to heat and noise.
Material and Methods: In this experimental study, 72 individuals (36 men and 36 women) aged between 23 and 33 years participated according to the inclusion criteria. In total, 12 different test modes were performed (3 temperature levels and 4 noise pressure levels). The test was conducted for each person in 4 steps during a specific day. The duration of exposure to each condition was half an hour, and a half-hour rest was given between each test condition. Saliva samples of each subject were collected before and immediately after exposure to noise and heat. Also, The Integrated Visual and Auditory (IVA) was recorded by the participants simultaneously.
Results: The results of combined exposure to noise and heat on visual and auditory attention showed that only two modes of combined exposure, SPL95+WBGT34 and SPL95+WBGT29, caused a significant increase (P < 0.05) in mental workload and a significant decrease (P < 0.05) in visual and auditory attention. In addition, the results showed that independent exposure to noise at the levels of 85 and 95 dB and exposure to heat at higher temperature levels of 34 and 29 degrees Celsius cause a significant increase (P < 0.05) in salivary cortisol after exposure. The results of the effect of combined exposure to noise and heat on salivary cortisol showed that three experimental modes of combined exposure (SPL85+WBGT34, SPL95+WBGT29, and SPL95+WBGT34) caused a noticeable and significant (P<0.001) increase in salivary cortisol.
Conclusion: Indeed, salivary cortisol can be recommended as a physiological index to evaluate noise and heat exposure. It’s also noteworthy that salivary cortisol is more affected by noise and heat exposure than cognitive performance.
Sajad Zare, Reza Esmaeili, Fardin Zandsalimi,
Volume 14, Issue 3 (10-2024)
Abstract

Introduction: Cognitive functions play a vital role in how tasks are performed; for this, temporary cognitive and mental dysfunctions could lead to grave consequences, especially when an accurate and prompt response is required. Attention and reaction time to noise are among the most effective exogenous factors on the brain processing mechanism. This study aimed to measure the sustained attention of workers in the steel industry exposed to different sound pressure levels. 
Material and Methods: The study was conducted in 4 general stages, including 1- Selecting predictive orientation variables (age, work history, different sound pressure levels); 2- Conducting the Cognitive Performance Test (CPT); 3 Conducting N-BACK Cognitive Performance Test and 4- Modeling cognitive performance changes using model precision methods.
Results: Continuous Performance Test (CPT) results indicated that all three groups’ omission error, commission error, and response time were affected by shift time. All three components increased significantly as the shift ended, decreasing individuals’ cognitive function. Also, the higher noise impact in modeling CPT and N-Back tests indicated reduced workers’ concentration.
Conclusion: These study findings suggested that greater noise weight obtained in test modeling in three-time intervals, i.e., in the beginning, middle, and end of the shift, affected the continuous performance components of the CPT and working memory performance of the N-back test, including workers’ response time and reaction time, with workers’ rate of error increasing and their focus decreasing during the shift. 

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