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Showing 3 results for Reaction Time
Effects of Cooling Vests on Heat Strain Indicators and Reaction Time while Wearing Protective Clothing Against Chemical, Microbial, and Radioactive Contamination in Hot and Dry Laboratory Conditions
Habibollah Dehghan Shahreza, Firouz Valipour, Hossein Khalili Gorji, Behzad Mahaki,
Volume 3, Issue 4 (3-2016)
Abstract

Introduction: This study aimed to investigate the effects of cooling vests on heat strain and reaction time while wearing protective clothing against chemical, biological, and radioactive contamination.

Materials and Methods: Twelve male students with the mean age of 25 ± 2 years and mean body mass index (BMI) of 23.0 ± 1.5 kg/m2 were recruited in this experiment. Each student was asked to run on a treadmill at a speed of 2.4 km/h for 20 minutes. The experiments were performed at 35 °C and 30% relative humidity. Physiological strain index score, oral temperature, heart rate, reaction time, and number of errors were measured at the end of the two phases. The findings were analyzed by SPSS.

Results: According to Wilcoxon test, exercising with and without the cooling vest resulted in significantly different physiological strain index scores (P = 0.02), oral temperature (P = 0.02), reaction time (P = 0.02), heart rate (P = 0.02), and errors (P = 0.03). The mean physiological strain index score was 4.038 ± 0.882 without the cooling vest and 1.42 ± 0.435 with the cooling vest. The mean reaction times with and without the cooling vest were 0.539 ± 0.977 and 0.769 ± 0.0972, respectively.

Conclusion: The results of this study showed that using a cooling vest reduced the physiological strain, reaction time, and error rates in workers.


Evaluation of Effects of Different Levels of Brightness on Attention and Reaction Time under Laboratory Conditions
Habibollah Dehghan, Zohre Mohebian, Ghasem Yadegarfar,
Volume 4, Issue 4 (3-2017)
Abstract

Introduction: Few studies were conducted to determine the effects of lighting on cognitive performance. However, they could not reach a decisive conclusion. This study investigated cognitive performance of university students exposed to different levels of lighting under laboratory conditions.

Methods: In this experimental study, 33 subjects (age range 19-26 years) performed cognitive tests. Participants were exposed to three levels of lighting (200, 500 and 1500lux) in laboratory conditions while performing CPT tests to investigate percentage of attention and reaction time machine that measures reaction time.

Results: The results of this study showed that the maximum percentage of attention (99.75%) belonged to lighting of 1500 (lux) and the minimum percentage of attention was related to 500(lux) (99.36%). statistical analysis showed significant differences in percentage of attention in different levels of lighting (P=0.004). In addition, results of data analysis showed that increase in intensity of  lighting can make a significant change in the average response time (P˂0.001), correct response (P=0.004), commission error (P=0.001) and omission error (P=0.017). With increasing the lighting intensity, reaction time has decreased. The reaction time showed significant differences  at all levels of lighting (P˂0.001)

Conclusion: According to the findings of this study, lighting causes a decrease in reaction time and increase in attention. Thus, the lighting should be taken into account while designing of job and tasks which need attention or reaction time.


Investigation of Subjective Thermal Sensation and Its Relationship with Stress, Anxiety, Depression and Cognitive Function of Students of Isfahan University of Medical Sciences
Samira Barakat, Habibollah Dehghan, Hossein Ebrahimi, Behnam Moradi,
Volume 9, Issue 2 (10-2021)
Abstract
Background & Objectives: Thermal sensation is not a direct sense of air temperature but is related to people's feelings, sensory experience and psychological phenomenon, which 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.
Methods: This study was descriptive-analytical and 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.
Results: 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% of 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.
Conclusion: 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 selective.

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