Effects of different physical workload parameters on mental workload and performance (original) (raw)
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Applied Psychology-an International Review-psychologie Appliquee-revue Internationale, 2004
and simultaneously (dual task). The results of the ANOVAs performed showed that there are no differences with regard to the three instruments' intrusiveness, and that among the three subjective workload instruments WP has an outstanding sensitivity to the different task manipulations. To evaluate the diagnosticity of each of the three instruments canonical discriminant analysis was used, and this demonstrated that the three multidimensional ratings provided diagnostic information on the nature of tasks demands that was consistent with the a priori task characterisation. However, the diagnostic power of WP was clearly superior to that obtained using TLX or SWAT. Pearson correlations between each performance and each subjective workload measure were calculated to evaluate the concurrent validity of each instrument with task performance, and to assess the convergent validity of the instruments. The three coefficients were positive and near to one, showing the high convergent validity of the three instruments considered in this research. Implementation requirements and subject acceptability were also compared. Finally, practical implications on the three assessment approaches are mentioned.
EFFECTS OF INTERACTION BETWEEN PHYSICAL AND MENTAL WORKLOAD ON HUMAN PERFORMANCE
Workload is an important factor that affects human performance in an operating system. This research study investigates the interaction of physical workload, mental workload and arousal level on performance and working memory. Fifteen participants (ages 25-35) performed a physical task (pedalling on a bicycle-ergometer) under three different levels of resistance load (low, mid and high) concurrently with a mental task (arithmetic) at three levels of demand (simple, intermediate and difficult). Participants also completed two subjective assessments following the task, Borg-CR10 and NASA-TLX to evaluate the perceived physical and mental workload respectively. The hypothesis of the study is that optimum performance occurs at intermediate levels of workload, whereas poor performance is observed at the low and high levels of physical and mental demand due to underload and overload.
2011
Workers experience combined physical and mental demands in their daily jobs, yet the contribution of these concurrent demands in the development of work-related musculoskeletal disorders (WMSDs) is not clearly understood. There is a need to understand how concurrent demands interact with different work parameters, such as force levels, muscles employed, and types of exertion, to influence physiological responses. Furthermore, whether muscle capacity is altered with these concurrent demands remains unclear. The current research was conducted to address these needs through three experimental studies that evaluated changes in physiological, performance, and subjective measures. The first study investigated muscle-specific responses to concurrent physical and mental demands during intermittent static work. Mental demands adversely affected physiological responses with increasing physical demand. Furthermore, greater motor and mental performance impairment was observed at either end of the physical demand spectrum. Finally, these interactions were muscle-dependent, with postural (shoulder and torso) muscles indicating a greater propensity to interference due to concurrent demands than executive (wrist) muscles. The aim of the second study was to evaluate differential effects of exertion type (static and dynamic) during concurrent physical and mental work. Concurrent physical and mental demands adversely affected physiological responses during static exertions compared to dynamic exertions. Furthermore, static exertions were more susceptible to decrements in muscle output and mental task performance than dynamic exertions, specifically at higher force levels. The last study quantified the effects of concurrent physical and mental demands on muscle capacity (endurance, fatigue, and recovery) during intermittent static work. Additional mental processing was associated with shorter endurance times, greater strength decline, increased fatigability, and slower cardiovascular recovery. Concurrent demand conditions were also associated with higher levels of perceived fatigue, and rapid increases in rates of perceived exertion, time pressure, mental load, and stress. Overall, the current research provides a comprehensive understanding of the interactive effects of physical and mental demands on physiological responses and task performance. These findings may facilitate the development of task design strategies to help reduce the risk of workplace injuries and to increase worker performance. Finally, outcomes from this research can contribute towards the revision of current ergonomic guidelines to incorporate concurrent assessment of physical and mental demands.
The Subjective Workload Assessment Technique: A Scaling Procedure for Measuring Mental Workload
Advances in Psychology, 1988
We d e s c r i b e t h e SWAT procedure as a twophased method t h a t i n c l u d e s (a) a s c a l e developnent phase based on c o n j o i n t measurement and nonmetric s c a l i n g , and (b) an event s c o r i n g phase. The developnent o f SWAT and i t s measurement f o u n d a t i o n s a r e discussed. Recent research i l l u s t r a t i n g SWAT'S widespread u t i l i t y and i t s s e n s i t i v i t y as a measure o f perceived mental workload i s summarized.
Multivariate workload evaluation combining physiological and subjective measures
International Journal of Psychophysiology, 2001
This paper suggests a way to integrate different parameters into one index and results obtained by a newly developed index. The multivariate workload evaluation index, which integrates physiological parameters and one subjective parameter through Principle Components Analysis, was proposed to characterize task specific responses and individual differences in response patterns to mental tasks. Three different types of mental tasks were performed by 12 male participants. Heart rate variability, finger plethysmogram amplitude, and perspiration were used as physiological parameters. Three subscales, mental demand, temporal demand and effort out of six subscales in the NASA-Task Load Index were used as subjective scores. These parameters were standardized within each participant and then combined. It was possible to assess workload using this method from two different aspects, i.e. physiological and subjective, simultaneously.
Factors Influencing Mental Workload Indexes
Journal of UOEH, 1997
Kay worcls' Several findings of the author7s own mental workload rcsearch are reviewed, Especially, factors, except task demand, influencing rnental workload indexes are discussed, First, an experiment using the National Aeļ½„ronautics and Space Administration '1'ask Load Index (NASA TI.X) is reviewed and the efll).cts ef a prior task load on a subsequent subjectixie workload are : mental task, workload, subjective measures, psychophysiological measures,