“CALM YOURSELF”: THE AROMATIC REGULATION OF THE PSYCHOPHYSIOLOGY OF MOODFrederic R. Gaudios, Jr., Adam S. Mussell, Dr. Jeannette M. Haviland-Jones, & Dr. John M. Ackroff

The Human Emotions Laboratory, Department of Psychology, Rutgers University, Piscataway, NJ, USA

Supported by International Flavors & Fragrances Inc., Union Beach, NJ, USA andThe Jerome and Lorraine Aresty Research Center for Undergraduates

AbstractThirty-six Rutgers University students (18 male, 18 female) viewed three videos while exposed to one of three odors (Citrus, Powder, or control) and attached to physiological equipment recording thoracic respiration and galvanic skin response (GSR). Videos used in this study were computer-generated animations previously shown to elicit the emotions of fear, happiness, and sadness in a context-independent manner. The Fear video elicited fear and increased respiration and GSR, the Sad video elicited sadness, and the Happy video elicited happiness and increased GSR. Respiration and GSR dropped significantly at the beginning of the baseline compared to the final 60 seconds of the Fear and Happy videos. Citrus odor showed increased respiration across all videos compared to the other odors.

Odors are found everywhere, and their influence on emotional experience has recently received a great deal of attention from the scientific community. Since Richard Axel and Linda B. Buck were awarded the 2004 Nobel Prize in Medicine for outlining the anatomy and physiology of the olfactory system, research on the long-standing psychological belief that odor and emotional processing in the brain were strongly intertwined has led to new research directions. Mood can influence behavior; long-term effects of mood are found on cognition and health (Fredrickson & Losada, 2005). Odors are also involved in associative learning. Herz, Schankler, and Beland (2004) found participants performed a moderately-challenging puzzle task more quickly and self-reported higher levels of frustration when exposed to the same odor experienced during an earlier frustrating computer-game task. A preferred method for emotion elicitation has been the presentation of emotionally charged film clips or Hollywood movies. Gross and Levenson (1995) used several movies (e.g. Silence of the Lambs, When Harry Met Sally) to elicit anger, disgust, fear, sadness and several other emotions. The inherent problem with using unpleasant film clips, and especially Hollywood movies, is the context-dependent nature of the stimulus and any previous experience the participant has had with the stimulus. For a baseline task, Palomba et al. (2000) first used a sine wave oscillating at 8 cycles per minute with overall success. Piferi et al. (2000) found a decrease in systolic and diastolic blood pressure when participants viewed a video compared to sitting still. Specific responses to odor were found by Alaoui-Ismaili et al. (1997) by monitoring several autonomic measures, including GSR, respiratory frequency, and heart rate, in participants exposed to odors of varying pleasantness. Bensafi et al. (2002) found pleasant odors were correlated with heart rate variations and odors rated as highly arousing showed a correlation with skin conductance variations.

Method Thirty-six Rutgers University students (18 female, 18 male) volunteered to participate in “Calm Yourself”. Three odors were used: Citrus, Powder, and DEP, an organic solvent free of any natural odor. The solvent was used to dilute the experimental odors such that they had equal intensities. All odors were designed and previously studied by International Flavors & Fragrances, Inc. 1.3 mL of one odor was placed on a gauze pad worn by each participant as a “fragrance necklace.” Three six-minute videos designed by the Human Emotions Laboratory at Rutgers University to elicit specific emotions (fear, sadness, or happiness) were used. They consisted of computer animations generated using Macromedia Flash software and are believed to be context-independent stressors. Each participant saw all videos in a randomized order. Physiological baselines were achieved by alternating 5-minute sine wave oscillations (at 8 cycles/min) between videos. Participants were given the option to match breathing to the sine wave presentation. Physiological measures (thoracic respiration and skin conductance response [SCR]) were acquired using MP100 transducer hardware manufactured by BIOPAC, Inc., and provided by IFF. Respiration rate was recorded via a transducer centered at the bottom of the participant’s sternum. Two silicon GSR electrodes were placed on the palmar surface of each participant’s left hand. Acqknowledge 3.7.3 software (developed by BIOPAC, Inc. and provided by IFF) was used for data recording. To eliminate potential discomfort, same-sex assistants attached the electrodes. Differential Emotional Scales (Izard et al., 1974) were filled out by participants before odor application, after odor application, after viewing the first baseline presentation, and in response to the three videos. DES for the videos were filled out retrospectively, after all videos had been seen.

Results, continued On the DES, the Happy video was rated significantly more happy than the Sad, t(33) = 8.93, p < .01, or Fear, t(33) = 7.62, p < .01 videos.

For the interest/excitement rating, the Sad video was different from both Happy, t(33) = 4.00, p < .05, and Fear, t(33) = 4.33, p < .05.

On the DES, a significant main odor effect, F(2, 30) = 3.35, p < .05 revealed that all emotion ratings for the Citrus odor condition to be higher than those for the control condition, t(30) = 3.56, p < .05.

By order, GSR, t(150) = 7.97, p < .01, and respiration rate, t(150) = 4.59, p < .05, showed distinct returns to baseline following the first video only.

By video, respiration showed a distinct return to baseline after the Happy, t(150) = 4.11, p < .05, and Fear, t(150) = 4.80, p < .05, videos.

By video, respiration difference scores for transitions were robust for the Happy, t(150) = 4.47, p < .05, and Fear videos, t(150) = 6.66, p < .01.

By order, the Citrus odor increased respiration rate compared to control odor during all videos (tbefore(30) = 3.50, p < .05; tafter(30) = 3.51, p < .05).

By video, the Fear video increased respiration rate compared to the “before” baseline, t(150)= 6.05, p < .01, and Happy and Fear videos increased respiration rate compared to the “after” baseline; Happy, t(150)= 4.11, p < .05; Fear, t(150)= 4.80, p < .05.

Discussion Participants exposed to the Citrus odor showed more reactive self-reported moods and higher respiration rate than those exposed to control odor for all videos. Since emotions are multi-faceted systems that affect mood, behavior, and physiology, the Citrus odor may have served as an emotional activator, facilitating behavioral and physiological responses (Fredrickson & Losada, 2005). The Fear and Happy videos proved to elicit their respective emotions as shown by increased respiration rate. While both videos influenced respiration rate identically, the Happy video probably caused a general state of sympathetic activation due to the video’s positive content rather than an autonomic fear response. The Happy video also elicited happiness based on self-reported moods, but analysis of the means showed that Happy maintained baseline happiness, whereas Sad and Fear videos decreased it. Since two-thirds of the participants viewed Happy immediately following one of the two negatively charged clips, Happy may elicit an “emotional return to baseline”, although further research is needed to determine this empirically. The increased respiration rate at the start of the Fear and Happy videos may be attributed to a sympathetic startle response that normalized over time. With regard to the baseline task, the increased respiration rate found during the Happy and Fear videos decreased significantly at the onset of the following baseline, marking a return to baseline and validating the calming nature of the sine wave. For the Fear video, respiration rate decreased at greater levels than the increase observed at the beginning of the video. This may mark a super-return to baseline that must be further explored. While no return to baseline was found for GSR during the first 60 seconds, visual inspection of the data show that the return did occur. This suggests a greater latency in GSR. Results show that exposure to the Citrus odor facilitated a subjective emotional response elicited through context-independent video clips. The emotion labels of the Happy and Fear videos were also validated. This emotional response led to an increased intensity of autonomic stress response. Further research could attempt to validate with different odors, or explore odor effects on other physiological measures. Developmental studies could attempt to quantify any changes in odor regulation associated with puberty, and cognitive studies could attempt to correlate the effects of odor regulation to decision-making or problem solving skills.

Effect of Odor on Self-Reported Emotion Rankings (Difference in Video Scores Compared to Baseline Scores)

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ReferencesAlaoui-Ismaili, O., Vernet-Maury, E., Dittmar, A., Delhomme, G., & Chanel, J. (1997). Odor hedonics: connection with emotional response estimated by autonomic parameters. Chemical Senses, 22, 237-248. Bensafi, M., Rouby, C., Farget, V., Bertrand, B., Vigouroux, M., & Holley, A. (2002). Autonomic Nervous System Responses to Odours: the Role of Pleasantness and Arousal. Chemical Senses, 27, 703-709.

Fredrickson, B.L. & Losada, M.F. (2005). Positive Affect and the Complex Dynamics of Human Flourishing. American Psychologist, 60, 678-686.

Gross, J.J., & Levenson, R.W. (1995). Emotion elicitation using films. Cognition and Emotion, 9, 87-108.

Herz, R. S., Schankler, C., and Beland, S. (2004). Olfaction, Emotion, and Associative Learning: Effects on Motivated Behavior. Motivation and Emotion, 4, 363-383.

Izard, C.E., Dougherty, F.E., Bloxom, B.M., & Kotsch, N.E. (1974). The Differential Emotions Scale: A method of measuring the meaning of subjective experience of discrete emotions. Nashville: Vanderbilt University, Department of Psychology.

Palomba, D., Sarlo, M., Angrilli, A., Mini, A., & Stegagno, L. (2000). Cardiac responses associated with affective processing of unpleasant film stimuli. International Journal of Psychophysiology, 36, 45-57.

Piferi, R., Kline, K., Younger, J. & Lawler, K. (2000). An alternative approach for achieving cardiovascular baseline: viewing an aquatic video. International Journal of Psychology, 37, 207-217.

Effect of Odor on Respiration Rate, Videos in Comparison with Baselines

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Results A split-plot analysis of variance was used, with odor and gender as between-participant variables, and video within-participants. Tukey’s HSD was used for post hoc pairwise comparisons. Data were analyzed for effect of order and video. For physiological data, both the first 60 seconds of each event and the 60 seconds surrounding each transition between events were analyzed. No order effects were found, so findings of effects of video were not confounded.

Research sponsored by:

Effect of the Baseline following Happy and Fear videos on Respiration Rate

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