Theoretical and Methodological Issues in Psychophysiological Research
Anthony W. K. Gaillard
TNO Human Factors Research Institute, The Netherlands
Arthur F. Kramer
University of Illinois, Urbana--Champaign
There is renewed interest in using psychophysiological measures in the workplace (see, e.g., Boucsein, Luczak, Stern, & Yagi, 1996; Caldwell et at., 1994; Gaillard, Boucsein, & Stern, 1996). This interest has been stimulated by a host of factors ranging from new measurement technologies to the development of new theoretical approaches. Attempts at using physiological indices before the 1980s were hampered by technical problems: the nonportability of the apparatus and the loss of data due to recording artifacts. Ambulatory equipment and data analysis have progressed considerably since then. The equipment available in 1999 is small, relatively inexpensive, and user-friendly.
In the 1970s the research efforts of psychophysiologists were focused on finding the "golden yardstick" with which workload could be measured. Early ideas of a direct relationship between workload and physiological measures have changed. Investigators no longer adhere to a one-dimensional concept of arousal in which the difficulty of the task is associated with increases in the level of physiological activity. The strategy of recording many psychophysiological variables to measure workload has been replaced by more sophisticated approaches. A selected set of variables is chosen to investigate specific effects of workload and of the work environment on the state, efficiency, and well-being of the employee. Different reactivity patterns may be identified on the basis of