Psychophysiological recording has been shown to be a valuable tool in evaluating stress--strain processes that may typically emerge during HCI. Because the amount of physical strain is relatively low during computer work, different psychophysiological marker variables may be chosen for detecting the amount of mental and emotional strain in this kind of research. Mental workload during VDT operations can be determined by means of changes in cardiac activity such as a decrease in HRV, by changes in EEG measures, such as an increased P300 amplitude or theta activity, and by an increase in catecholamine excretion. On the other hand, strain that emerges from the more emotion-related aspects of workload will appear as an increase in spontaneous electrodermal activity.
Another important goal that may be achieved by means of psychophysiological recordings is determining the optimal duration and schedule of necessary breaks during HCI. In particular, psychophysiological recovery during breaks can be used as a measure of predicting the feasibility of a given rest/break schedule for the prevention of VDT work-related diseases that may result from accumulated psychophysiological strain.
My opinion is that the use of psychophysiological tools should be backed up by appropriate modeling. The neurophysiologically based model provided in chapter 1 may serve as such an attempt, predicting that cardiovascular markers, such as HRV, can be used as easy-to-measure indicators for mental strain, whereas electrodermal variables form an equivalent for the emotional area of cognitive impairment. Such an approach, however, cannot be conducted with recordings from one single psychophysiological system but requires multivariate methodology (see Table 1.1 in chap. 1, this volume). Recommendations for an optimal design of both hard- and software may be developed using psychophysiological results from laboratory and field settings as shown in this chapter.
Åborg C., Fernström E., & Ericson M. O. ( 1995). "Psychosocial and physiological effects of reorganizing data entry work--a longitudinal study". In A. Grieco, G. Molteni, B. Piccoli, & E. Occhipinti (Eds.), Work with display units 94 (pp. 63-66). Amsterdam: Elsevier.
Barber R. E., & Lucas H. C. ( 1983). "System response time, operator productivity, and job satisfaction". Communications of the ACM, 26, 972-986.
Boucsein W. ( 1992). Electrodermal activity. New York: Plenum.
Boucsein W. ( 1993). "Psychophysiology in the computer workplace--goals and methods". In H. Luczak, A. Çakir, & G. Çakir (Eds.), Work with display units 92 (pp. 135-139). Amsterdam: North-Holland.
Boucsein W., Greif S., & Wittekamp J. ( 1984). Systemresponsezeiten als Belastungsfaktor bei Bildschirm-Dialogtätigkeiten [System response times as a cause for stress at dia-