EFFECTS OF OLFACTORY STIMULATION 205 Ceiling Light Fragrance Line Apple lie Storage Intercom M•crocomputer Box Bell Figure 2. Schematic drawing of the experimental chamber. Air Purifier ratory, subjects were requested not to wear cologne or perfume. All subjects complied with this request. RESULTS VIGILANCE PERFORMANCE Percentages of correct detections and false alarms were determined for each subject during each period of watch. Preliminary inspection of the data revealed that gender and time of day had little effect upon performance. Accordingly, the data were collapsed across these factors for further analyses. Mean percentages of the correct detections for the air, Muguet, and Peppermint groups are plotted as a function of periods in Figure 3. It is evident in the figure that the detection scores for both fragrance groups were similar and that for both groups the percentage of detections was substantially and consistently greater than that for the unscented air control. The figure also shows that the detection percentage in all groups declined over time. An analysis of variance of the detection scores revealed that the

206 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Z O 90 80 7O 6O 5O 40 30 I I I I I I I I 1 2 3 4 I Air i • Muguet ß Peppermint I PERIODS OF WATCH (10MIN.) Figure 3. Percentage of correct detections as a function of periods of watch for subjects in the air, Muguet, and Peppermint conditions. difference between groups reached statistical significance [F(2,33) = 3.25 p = 0.05] and that performance efficiency deteriorated significantly over time [F(3,99) = 6.30 p 0.001]. The groups X periods interaction lacked significance [F(6,99) = 1.17 p 0.05]. False alarms were generally few in all conditions. Mean percentages of false alarms for the four periods of watch were 2.7%, 1.8%, 2.0%, and 2.3 %, respectively, for the air group 8.9%, 6.7%, 6.2%, and 5.9%, respectively, for the group exposed to Muguet and 12.4%, 7.2%, 9.3%, and 7.0%, respectively, for subjects exposed to Peppermint.