The present project originated in an interest in testing the hypothesis that certain fragrances have an inherent ability to affect peoples’ level of physiological arousal independently of their hedonic properties. Empirical data supporting that hypothesis were quite limited, however, and came from two kinds of sources: subjective reports (Schwartz, Whitehorn, Heron, & Jones, 1986) and electroencephalographic (EEG) records (Lorig & Schwartz, 1988; Lorig, Schwartz, Herman, & Lane, 1988). We proposed to study the behavioral effects of such fragrances, using a laboratory analogue of a class of important real-world tasks known as vigilance or sustained attention tasks.
In vigilance tasks, people monitor a display over extended periods of time, looking for infrequently occurring “signals,” the kind of tasks that might occupy radar operators, quality control inspectors, nuclear power plant operators, long distance drivers, and so on. The most ubiquitous finding in research on vigilance performance is that subjects’ efficiency, though initially high, declines over time on task (Demher & Warm, 1979). Substantial differences are also noted in overall level of performance as a function of task and subject characteristics.
While theories of vigilance performance, and especially of the typical decline in performance that occurs over time (the “vigilance decrement”), point to a variety of causal factors, in many of those theories (see Parasuraman, 1984) poor performance is attributable to a low level of arousal. Thus, if there are fragrances which affect arousal level, then their administration during the course of a vigilance task should be expected to affect performance efficiency. Our research to date has been designed to test that notion.
