State of science: mental workload in ergonomics

Abstract

Mental workload (MWL) is one of the most widely used concepts in ergonomics and human factors and represents a topic of increasing importance. Since modern technology in many working environments imposes ever more cognitive demands upon operators while physical demands diminish, understanding how MWL impinges on performance is increasingly critical. Yet, MWL is also one of the most nebulous concepts, with numerous definitions and dimensions associated with it. Moreover, MWL research has had a tendency to focus on complex, often safety-critical systems (e.g. transport, process control). Here we provide a general overview of the current state of affairs regarding the understanding, measurement and application of MWL in the design of complex systems over the last three decades. We conclude by discussing contemporary challenges for applied research, such as the interaction between cognitive workload and physical workload, and the quantification of workload 'redlines' which specify when operators are approaching or exceeding their performance tolerances.

A Comprehensive Approach for the Ergonomic Evaluation of 13 Emergency and Transport Ventilators

“…Mental work load is used as a valid and reproducible indicator for human/machine interface development and comparison. 12,13 Mental work load monitoring enables the depiction of differences that will not be observed when using standard objective and subjective tests. NASA-TLX is a multidimensional tool that was developed by the National Aeronautics and Space Administration's Ames Research Center in 1986 and validated in 1988 for perceptual work load evaluations using task-load index (TLX) measurement.…”

“…Second, the NASA-TLX results should be considered with caution because ergonomic assessment and mental work load are new notions in emergency practice, and NASA-TLX is a difficult test to interpret. 13 Before each test and for each participant, we explained the progress analyses and the fact that it was emergency and transport ventilator ergonomics that was being evaluated and not the physicians' own capabilities. Finally, we used a computerized NASA-TLX version, which has been associated with a higher mental work load value than the paper-and-pencil version.…”

Assessment of Psychosocial Risks and Mental Stress at Work: The Development of the Instrument OrgFit

“…As workload, or specifically mental workload "has intuitive appeal, but remains surprisingly difficult to define" [12] it is important to use clear definitions. In the norm ISO 10075-1 [8], mental workload is used as an umbrella term that encompasses mental stress and mental strain.…”

Understanding the human performance envelope using electrophysiological measures from wearable technology

“…Broadly, we align the measures taken with the concept of mental workload as an explanatory concept. Mental workload is a key performance shaping variable in aviation operations (Dahlstrom and Nahlinder 2006) and more general in human factors as a whole (Young et al 2014). Clearly, mental workload represents only part of the performance story, and we would expect interactions between different variables identified by Edwards et al (2012).…”