MEASUREMENT OF MENTAL WORK LOAD AND OF ACCEPTABLE LOAD: POSSIBLE APPLICATIONS IN INDUSTRY

Abstract

In experiments to assess mental work load the effect of the central choice making system being the weakest link is demonstrated, using a binary choice generator. It was found that increasing the number of binary choices per minute diminished the irregularity of the rest pattern (Sinus Arrhythmia) without affecting the level of heart rate. A simple scoring method for the use of sinus arrhythmia is put forward and different tasks are scaled according to the progressive suppression of sinus arrhythmia. Referring to experiments showing that the central choice making mechanisms are operating as a single channel, the “method of distraction stress” is introduced. The deterioration of experimental performance by this method is described and compared with the deterioration caused by other sources of stress. Finally the concepts of reserve-capacity and “willing-to-spend” capacity are discussed.