Current concerns in the assessment of mental workload are discussed, and the event-related brain potential (ERP) is introduced as a promising mental-workload index. Subjects participated in a series of studies in which they were required to perform a target acquisition task while also covertly counting either auditory or visual probes. The effects of several task-difficulty manipulations on the P300 component of the ERP elicited by the counted stimulus probes were investigated. With sufficiently practiced subjects the amplitude of the P300 was found to decrease with increases in task difficulty. The second experiment also provided evidence that the P300 is selectively sensitive to task-relevant attributes. A third experiment demonstrated a convergence in the amplitude of the P300s elicited in the simple and difficult versions of the tracking task. The amplitude of the P300 was also found to covary with the measures of tracking performance. The results of the series of three experiments illustrate the sensitivity of the P300 to the processing requirements of a complex target acquisition task. The findings are discussed in terms of the multidimensional nature of processing resources.
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References
1.
Bainbridge, L.Forgotten alternatives in skill and workload. Ergonomics, 1978, 21, 169–185.
2.
Berlyne, D. E.Conflict, arousal and curiosity. New York: McGraw-Hill, 1960.
3.
Brown, I. D.Dual task methods of assessing workload. Ergonomics, 1978, 21, 221–224.
4.
Borg, G.Subjective aspects of physical and mental load. Ergonomics, 1978, 21, 215–220.
5.
Chiles, W. D.Objective methods. In A. H. Roscoe (Ed.) Assessing pilot workload (AGARD-A6-233). Neuilly-sur-Seine, France: Advisory Group for Aerospace Research and Development (NATO), 1978.
6.
Donchin, E.A multivariate approach to the analysis of average evoked potentials. IEEE Transactions on Bio-Medical Engineering, 1966, BME-13, 131–139.
7.
Donchin, E.Brain electrical correlates of pattern recognition. In G. F. Inbar (Ed.) Signal analysis and pattern recognition in biomedical engineering. New York: Wiley, 1975.
Donchin, E., and Heffley, E.Minicomputers in the signal averaging laboratory. American Psychologist, 1975, 30, 299–312.
10.
Donchin, E., and Heffley, E.Multivariate analysis of event related potential data: A tutorial review. In D. Otto (Ed.) Multidisciplinary perspectives in event related brain potential research (EPA 600/9-77-043). Washington, DC: U.S. Government Printing Office, 1979.
11.
Donchin, E., Kramer, A., and Wickens, C. D.Probing the cognitive infrastructure with event-related brain potentials. Proceedings of the AIAA Workshop on Flight Testing to Identify Pilot Workload and Pilot Dynamics. Washington, DC: U.S. Govt. Printing Office, 1982.
12.
Donchin, E., Ritter, W., and McCallum, W. C.Cognitive psychophysiology: The endogenous components of the ERP. In E. Callaway, P. Tueting, and S. H. Koslow (Eds.) Event-related brain potentials in man, New York: Academic Press, 1978.
13.
Duncan-Johnson, C. C., and Donchin, E.On quantifying surprise: The variation in event-related potentials with subjective probability. Psychophysiology, 1977, 14, 456–467.
14.
Eason, R. G., Harter, R. M., and White, C. T.Effects of attention and arousal on visually evoked cortical potentials and reaction time in man. Physiology and Behavior, 1969, 4, 283–289.
15.
Eason, R. G., and Ritchie, G. Effects of stimulus set on early and late components of visually evoked potentials. Paper presented at the 17th Annual Meeting of the Psychonomic Society, St. Louis, 1976.
16.
Eggemeier, F. T.Some current issues in workload assessment. In Proceedings of the Human Factors Society 24th Annual Meeting, Santa Monica, CA: Human Factors Society, 1980.
17.
Ellis, G. A.Subjective assessment pilot opinion measures. In A. H. Roscoe (Ed.) Assessing pilot workload (AGARD-A6-233) Neuilly-sur-Seine, France: Advisory Group for Aerospace Research and Development (NATO), 1978.
18.
Hansen, J. C., and Hillyard, S. A.Endogenous brain potentials associated with selective auditory attention. Electroencephalography and Clinical Neurophysiology, 1980, 49, 277–290.
19.
Hartman, B. O.Time and load factors in astronaut proficiency. In B. E. Flaherty (Ed.) Symposium on psychophysiological aspects of space flight, New York: Columbia University Press, 1961.
20.
Hillyard, S. A., Hink, R. I., Schwent, V. L., and Picton, T. W.Electrical signals of selective attention in the human brain. Science, 1973, 182, 177–180.
21.
Howitt, J. S.Flight deck workload studies in civil transport aircraft. NATO AGARD Conference Proceedings, 1968, 56, 1–7.
22.
Isreal, J. B., Chesney, G. L., Wickens, C. D., and Donchin, E.P300 and tracking difficulty: Evidence for multiple resources in dual-task performance. Psychophysiology, 1980, 17, 259–273. (a)
23.
Isreal, J. B., Wickens, C. D., Chesney, G. L., and Donchin, E.The event-related brain potential as an index of display-monitoring workload. Human Factors, 1980, 22, 211–224. (b)
24.
Isreal, J. B., Wickens, C. D., and Donchin, E.The event-related brain potential as a selective index of display load. In Proceedings of the Human Factors Society 23rd Annual Meeting. Santa Monica, CA: Human Factors Society, 1979.
25.
Jasper, H. H.The ten twenty electrode system of the International Federation. Electroencephalography and Clinical Neurophysiology, 1958, 10, 371–375.
26.
Johannsen, C. G., and Corliss, W. R.Teleoperators and human augmentation (NASA SP-57045). Washington, DC: NASA, December, 1967.
27.
Johannsen, G., Moray, N.Pew, R.Ramussen, J., Sanders, A., and Wickens, C.Final report of the experimental psychology group. In N. Moray (Ed.) Mental workload: Its theory and measurement. New York: Plenum, 1979.
28.
Karis, D., Fabiani, M., and Donchin, E. P300 and memory: Individual differences in the Von Restroff effect. Cognitive Psychology, in press.
29.
Knowles, W. B.Operator loading tasks. Human Factors, 1963, 5, 155–161.
30.
Kutas, M., McCarthy, G., and Donchin, E.Augmenting mental chronometry: The P300 as a measure of stimulus evaluation time. Science, 1977, 197, 792–795.
31.
McCarthy, G., and Donchin, E.A metric for thought: A comparison of P300 latency and reaction time. Science, 1981, 211, 77–80.
32.
McDonald, B. L., and Ellis, N. C.Driver workload for various turn radii and speeds. Transportation Research Record, 1975, 530, 18–30.
33.
Moray, N.Subjective mental workload. Human Factors, 1982, 24, 25–40.
34.
Natani, K., and Gomer, F. E.Electrocortical activity and operator workload: A comparison of changes in the electroencephalogram and in event-related potentials (MDC E2427). St Louis, Missouri: McDonnell Douglas Corp., June, 1981.
35.
Norman, D. A., and Bobrow, D. G.On data limited and resource limited processes. Cognitive Psychology, 1975, 7, 44–64.
36.
North, R. A.Task components and demands as factors in dual task performance (TR-ARL-77-4/AFOSR 77-4). Champaign, IL: University of Illinois at Urbana-Champaign, Aviation Research Laboratory, 1977.
37.
Ogden, G. D.Levine, J. W., and Eisner, E. J.Measurement of workload by secondary tasks. Human Factors, 1979, 21, 529–548.
38.
Poon, L. W., Thompson, L. W., Williams, R. B., and March, G. R.Changes of antero-posterior distribution of CNV and late positive component as a function of information processing demands. Psychophysiology, 1974, 11, 660–673.
39.
Regan, D.Evoked potentials in psychology, sensory physiology and clinical medicine. London: Chapman & Hall, 1972.
40.
Rolfe, J. M.The secondary task as a measure of mental load. In W. T. Singleton, J. G. Fox, and D. Witfield (Eds.) Measurement of man at work. London:Taylor & Francis, 1971.
41.
Roscoe, A. H. (Ed). Assessing pilot workload. (AGARD-A6-233). Neuilly-sur-Seine, France: Advisory Group for Aerospace Research and Development (NATO), 1978.
42.
Rosler, F.Event-related brain potentials in a stimulus-discrimination learning paradigm. Psychophysiology, 1981, 18, 447–455.
43.
Schneider, W., and Shiffrin, R. M.Controlled and automatic human information processing: I. Detection, search and attention. Psychological Research, 1977, 84, 1–66.
44.
Schwent, V. L., Synder, E., and Hillyard, S. A.Auditory evoked potentials during multichannel selective listening: Role of pitch and localization cues. Journal of Experimental Psychology: Human Perception and Performance, 1976, 2, 313–325.
45.
Sheridan, T. B.Mental workload—What is it? Why bother with it?Human Factors Society Bulletin, 1980, 23, 1–2.
46.
Sheridan, T. B., and Ferrell, W. R.Man-machine systems. Cambridge, MA: MIT Press, 1974.
47.
Squires, K. C., Wickens, C. D., Squires, N. K., and Donchin, E.The effect of stimulus sequence on the waveform of the cortical event-related potential. Science, 1976, 193, 1142–1146.
48.
Sternberg, S.The discovery of processing stages: Extension of Donders' method. Acta Psychologica, 1969, 30, 276–315.
49.
Trumbo, D., Noble, M., and Swink, J.Secondary task interference in the performance of tracking tasks. Journal of Experimental Psychology, 1967, 73, 232–240.
50.
Van Voorhis, S., and Hillyard, S. A.Visual evoked potentials and selective attention to points in space. Perception and Psychophysics, 1977, 22, 54–62.
51.
Vidulich, M., and Wickens, C. D.Time-sharing manual control and memory search: The joint effects of input and output modality competition, priorities and control order. (EPL-81-4/ONR-81-4). Champaign, IL: University of Illinois at Urbana-Champaign, Engineering-Psychology Research Laboratory. December, 1981.
52.
Welford, A. T.Mental workload as a function of demand, capacity, strategy and skill. Ergonomics, 1978, 21, 151–167.
53.
Wickens, C. D.Human workload measurement. In N. Moray (Ed.) Mental workload: Its theory and measurement, New York: Plenum, 1979.
54.
Wickens, C. D.The structure of attentional resources. In R. Nickerson and R. Pew (Eds.) Attention and Performance VIII.Hillsdale, NJ: Erlbaum, 1980.
55.
Wickens, C. D., Derrick, W. D., Micallizi, J., and Beringer, D.The structure of processing resources. In Proceedings of the Human Factors Society, 24th Annual Meeting, Santa Monica, CA: Human Factors Society, 1980.
56.
Wickens, C. D., Gill, R., Kramer, A., Ross, W., and Donchin, E.The cognitive demands of second order manual control: Applications of the event-related brain potential. In Proceedings of the 17th Annual NASA Conference on Manual Control. Washington, DC: NASA, 1981.
57.
Wickens, C. D., Isreal, J. B., and Donchin, E.The eventrelated cortical potential as an index of task workload. In Proceedings of the Human Factors Society 21st Annual Meeting, Santa Monica, CA: Human Factors Society, 1977.
58.
Wickens, C. D., and Kessel, C.The effects of participatory mode and task workload on the detection of dynamic system failures. IEEE Transactions on Systems, Man & Cybernetics, 1979, SMC-9, 24–34.
59.
Wickens, C. D., Mountford, J. S., and Schreiner, W.Multiple resources, task-hemispheric integrity, and individual differences in time-sharing. Human Factors, 1981, 23, 211–230.
60.
Wierwille, W. W.Physiological measures of aircrew mental workload. Human Factors, 1979, 21, 575–594.
61.
Williges, R. C., and Wierwille, W. W.Behavioral measures of aircrew mental workload. Human Factors, 1979, 21, 549–574.
62.
Winer, B. J.Statistical principles in experimental design (2nd ed.). New York: McGraw-Hill, 1971.
