Slow Brain Potentials as a Measure of Effort? Applications in Mental Workload Studies in Laboratory Settings
Federal Institute for Occupational Safety and Health, Berlin, Germany
The use of information and communication technologies makes work tasks physically easier and minimizes exposure to traditional hazards. On the other hand, work is increasingly accompanied by information overload, time pressure, high levels of sustained attention and long working hours that may affect employees' well-being and health. The assessment of the various aspects of mental workload resulting from human--computer interaction remains a fundamental prerequisite for preventing potential work-related risks.
Kramer, Sirevaag, and Braune ( 1987) have described mental workload as the cost of performing a task in terms of a reduction in the capacity to perform additional tasks that use the same processing resource. Sanders ( 1983) elaborated a cognitive--energetical model of task performance that is based on a multiple resource view that combines both structural and energetical components. The structural level describes the flow of information through various processing stages from stimulus to response. At the energetical level, the physiological mechanisms of arousal, effort, and activation are distinguished. Whereas the arousal and activation components are hypothesized to be determined by involuntary factors, effort is under voluntary control, mediates response selection, and coordinates the arousal and activation subsystems ( Mulder, 1986; Pribram & McGuinness, 1975). Kok ( 1997) pointed out that these energetical mecha-