Basic emotions induced by odorants: a new approach based on autonomic pattern results

A scoping review of olfactory interventions for fatigue relief: addressing occupational health hazards

Background

Fatigue poses risks to occupational health and safety, affecting individuals' work efficiency, physical health, and social security, as well as human wellbeing and quality of life. Olfactory interventions, due to their low interference, are considered promising strategies for mitigating fatigue and reducing occupational health hazards.

Objective

The objective of this review is to bridge the current gaps in the literature by conducting a scoping review of olfactory interventions on human alertness. It aims to explore their application in various occupational settings and to provide comprehensive and practical guidance for the practical application of olfactory interventions in mitigating fatigue and reducing occupational risks.

Methods

The literature research was conducted in English using electronic databases such as Web of Science. Keywords related to scent and fatigue and the review followed PRISMA Extension for Scoping Reviews and PICO framework.

Results

28 studies were included in this work. Participant characteristics, fatigue measurement methods, and scent intervention methods, such as types of scents, intervention strategies, and scent presentation systems, are thoroughly investigated and discussed. Additionally, the study places a specific emphasis on the applications and research within the field of scent interventions for fatigue driving. Olfactory interventions have been applied to populations in various occupational fields, demonstrating beneficial effects on both physiological and psychological fatigue.

Conclusions

Olfactory intervention is effective and promising for enhancing alertness and improving the occupational environment. To provide detailed and practical guidance for the actual application of olfactory intervention in fatigue relief and reducing occupational health and safety hazards, further research into the potential mechanisms, applications, and efficacy assessment systems of fatigue-related olfactory interventions is necessary.

Nature and human well-being: The olfactory pathway

The world is undergoing massive atmospheric and ecological change, driving unprecedented challenges to human well-being. Olfaction is a key sensory system through which these impacts occur. The sense of smell influences quality of and satisfaction with life, emotion, emotion regulation, cognitive function, social interactions, dietary choices, stress, and depressive symptoms. Exposures via the olfactory pathway can also lead to (anti-)inflammatory outcomes. Increased understanding is needed regarding the ways in which odorants generated by nature (i.e., natural olfactory environments) affect human well-being. With perspectives from a range of health, social, and natural sciences, we provide an overview of this unique sensory system, four consensus statements regarding olfaction and the environment, and a conceptual framework that integrates the olfactory pathway into an understanding of the effects of natural environments on human well-being. We then discuss how this framework can contribute to better accounting of the impacts of policy and land-use decision-making on natural olfactory environments and, in turn, on planetary health.

Nocturnal exposure to a preferred ambient scent does not affect dream emotionality or post-sleep core affect valence in young adults

Emotions experienced within sleep mentation (dreaming) affect mental functioning in waking life. There have been attempts at enhancing dream emotions using olfactory stimulation. Odors readily acquire affective value, but to profoundly influence emotional processing, they should bear personal significance for the perceiver rather than be generally pleasant. The main objective of the present sleep laboratory study was to examine whether prolonged nocturnal exposure to self-selected, preferred ambient room odor while asleep influences emotional aspects of sleep mentation and valence of post-sleep core affect. We asked twenty healthy participants (12 males, mean age 25 ± 4 years) to pick a commercially available scented room diffuser cartridge that most readily evoked positively valenced mental associations. In weekly intervals, the participants attended three sessions. After the adaptation visit, they were administered the odor exposure and odorless control condition in a balanced order. Participants were awakened five minutes into the first rapid eye movement (REM) stage that took place after 2:30 a.m. and, if they had been dreaming, they were asked to rate their mental sleep experience for pleasantness, emotional charge, and magnitude of positive and negative emotions and also to evaluate their post-sleep core affect valence. With rs < 0.20, no practically or statistically significant differences existed between exposure and control in any outcome measures. We conclude that in young, healthy participants, the practical value of olfactory stimulation with self-selected preferred scents for enhancement of dream emotions and post-sleep core affect valence is very limited.

Reciprocal relationships between sleep and smell

Despite major anatomical differences with other mammalian sensory systems, olfaction shares with those systems a modulation by sleep/wake states. Sleep modulates odor sensitivity and serves as an important regulator of both perceptual and associative odor memory. In addition, however, olfaction also has an important modulatory impact on sleep. Odors can affect the latency to sleep onset, as well as the quality and duration of sleep. Olfactory modulation of sleep may be mediated by direct synaptic interaction between the olfactory system and sleep control nuclei, and/or indirectly through odor modulation of arousal and respiration. This reciprocal interaction between sleep and olfaction presents novel opportunities for sleep related modulation of memory and perception, as well as development of non-pharmacological olfactory treatments of simple sleep disorders.

A New Perspective of Sustainable Perception: Research on the Smellscape of Urban Block Space

The smell of space is inseparable from the sustainable development of the living environment. The research on olfactory perception and smell landscape has a positive effect on landscape design and urban planning and contributes to the formation and design optimization of unique urban memory. This study combines urban smell tracking experiments with Internet social media data analysis to classify smells in the old city center of Guangzhou, China, and analyzes the study within the inner ring and six historic districts. Based on the research results, the smell map was drawn, and the reliability of the smell map was tested through social data and semantic analysis. The emotional score heat map of smell and emotion in six regions was constructed, highlighting the impact of smell in key neighborhoods on the environment. In the conclusion to the study, the thematic routes of green urban design are proposed: sightseeing routes, cultural routes, and food routes, as well as improvement strategies to promote the integration of smell and urban operation activities and the sustainable development of urban regional characteristics.

Olfactory Stimulation and the Diagnosis of Patients With Disorders of Consciousness: A Double-Blind, Randomized Clinical Trial

OBJECTIVES

The aim of this study was to determine whether behavioral responses elicited by olfactory stimulation are a predictor of conscious behavioral response and prognosis of patients with disorders of consciousness (DOC).

METHODS

Twenty-three DOC patients (8 unresponsive wakefulness syndrome [UWS]; 15 minimally conscious state [MCS]) were recruited for this study in which 1-Octen-3-ol (familiar neutral odor) and pyridine were used to test odor behavioral responses, and water was used as an odorless stimulus. One rater presented the three odors in front of each patient's nose randomly, and another one videotaped all behavioral responses (e.g., pouting, wrinkling nose, slightly shaking head, frowning, etc.). Two independent raters, blind to the stimuli and the patient's diagnosis, gave the behavioral results according to the recorded videos. One-, 3-, and 6-month follow-up evaluations were conducted to obtain a good prognostic value.

RESULTS

All MCS patients showed behavioral responses to the 1-Octen-3-ol stimulus; nine MCS and one UWS showed olfactory emotional responses to the pyridine, and two MCS showed olfactory emotional responses to the water stimulus. The incidence of behavioral response was significantly higher using 1-Octen-3-ol than it was for water by McNemar test (p < 0.001), significantly higher using pyridine than it was for water (p < 0.01). The χ2 test results indicated that there were significant differences between MCS and UWS to 1-Octen-3-ol (p < 0.001). For MCS patients, the incidence of behavioral response was no different between using 1-Octen-3-ol and pyridine (p > 0.05). There was no significant relationship between the olfactory behavioral response and the improvement of consciousness based on the χ2 test analysis (p > 0.05).

CONCLUSION

Olfactory stimuli, especially for the familiar neutral odor, might be effective for eliciting a conscious behavioral response and estimating the clinical diagnosis of DOC patients.

CLINICAL TRIAL REGISTRATION

[https://clinicaltrials.gov/ct2/show/NCT03732092], [identifier NCT03732092].

The scent of attraction and the smell of success: crossmodal influences on person perception

In recent decades, there has been an explosion of research into the crossmodal influence of olfactory cues on multisensory person perception. Numerous peer-reviewed studies have documented that a variety of olfactory stimuli, from ambient malodours through to fine fragrances, and even a range of chemosensory body odours can influence everything from a perceiver's judgments of another person's attractiveness, age, affect, health/disease status, and even elements of their personality. The crossmodal and multisensory contributions to such effects are reviewed and the limitations/peculiarities of the research that have been published to date are highlighted. At the same time, however, it is important to note that the presence of scent (and/or the absence of malodour) can also influence people's (i.e., a perceiver's) self-confidence which may, in turn, affect how attractive they appear to others. Several potential cognitive mechanisms have been put forward to try and explain such crossmodal/multisensory influences, and some of the neural substrates underpinning these effects have now been characterized. At the end of this narrative review, a number of the potential (and actual) applications for, and implications of, such crossmodal/multisensory phenomena involving olfaction are outlined briefly.

A short-term musical training affects implicit emotion regulation only in behaviour but not in brain activity

Background

In everyday life, negative emotions can be implicitly regulated by positive stimuli, without any conscious cognitive engagement; however, the effects of such implicit regulation on mood and related neuro-mechanisms, remain poorly investigated in literature. Yet, improving implicit emotional regulation could reduce psychological burden and therefore be clinically relevant for treating psychiatric disorders with strong affective symptomatology.

Results

Music training reduced the negative emotional state elicited by negative odours. However, such change was not reflected at the brain level.

Conclusions

In a context of affective rivalry a musical training enhances implicit regulatory processes. Our findings offer a first base for future studies on implicit emotion regulation in clinical populations.

Effects of all-night exposure to ambient odour on dreams and affective state upon waking

Previous laboratory research has shown that exposure to odours of contrasting pleasantness during sleep differentially affects the emotional tone of dreams. In the present study, we sought to investigate how a generally pleasant (vanillin) and unpleasant (thioglycolic acid [TGA]) smell influenced various dream characteristics, dream emotions, and post-sleep core affect during all-night exposure, controlling for appraisal of the olfactory environment during the assessments and sleep stage from which the participants woke up. We expected that exposure to vanillin would result in more pleasant dreams, more positive and less negative dream emotions, and a more positive post-sleep core affect compared to the control condition, whereas exposure to TGA would have the opposite effect. Sixty healthy volunteers (36 males, mean age 24 ± 4 years) were invited to visit the sleep laboratory three times in weekly intervals. The first visit served to adapt the participants to the laboratory environment. On the second visit, half the participants were exposed to an odour (vanillin or TGA, 1:1) and the other half to the odourless control condition. On the third visit, they received control or exposure in a balanced order. On each visit, the participants woke up twice, first from the rapid eye movement (REM) sleep stage and then in the morning, usually from a non-REM sleep stage. Repeated measures were taken upon each awakening. Dream pleasantness, emotional charge of the dream, positive and negative emotions experienced in the dream, and four dimensions of post-sleep core affect (valence, activation, pleasant activation - unpleasant deactivation, and unpleasant activation - pleasant deactivation) were assessed. We found a small effect of condition (exposure vs. control) in interaction with appraisal of the ambient olfactory environment on dream pleasantness. Specifically, false alarms (i.e., perceiving odour in the absence of the target stimulus) were associated with lower dream pleasantness than correct rejections. Although exposure had a statistically significant positive influence on post-sleep core affect (namely, valence, activation, and pleasant activation - unpleasant deactivation), the size of the effect was small and lacked practical significance. The hypothesised differential effects of vanillin and TGA were only modelled for dream ratings because they decreased the fit of the other models. Neither dream pleasantness nor emotionality differed according to the odour used for stimulation. The results of the present study suggest that all-night exposure to odours is unlikely to produce practically significant positive effects on dreams and post-sleep core affect.

A systematic review of physiological responses to odours with a focus on current methods used in event-related study designs

OBJECTIVES

In odour research, there is still a lack of knowledge regarding the detailed understanding of the determinants and the magnitude of an odour's impact on human psychophysiology. Therefore, the present review aims to summarize current evidence on psychophysiological responses to olfactory events, to highlight diversity in research methods, and to provide recommendations for further research.

MATERIAL AND METHODS

Predefined search items were used for literature research in two databases, focussing on recent investigations of cardiac and electrodermal responses to short (<10 s) olfactory stimulations, combined with self-reports on odour experience, in a healthy population. The selected 27 publications were evaluated with regard to their methods and their findings on psychophysiological correlates of odour stimulation, following a conceptual scheme proposing mediating and moderating factors of physiological responses to odour stimuli.

RESULTS

The cardiac and electrodermal activity generally followed a discriminative pattern depending on the perceived pleasantness of an odour. Moreover, the trigeminal aspect of an odour stimulus became evident in electrodermal activity in several studies. Finally, for many of the here addressed potentially mediating and moderating variables, initial findings were obtained in some studies but these await corroboration by future research. With regard to the applied methodology, the reviewed studies were highly diverse, in terms of odour application, study design, and analysis of the time series data.

CONCLUSIONS

Future research is needed to advance our understanding of, and theoretical concepts beyond, psychophysiological responses to olfactory events, and to achieve experimentally validated methodological guidelines for psychophysiological measurements in olfaction research.

Effects of isotretinoin on the olfactory function in patients with acne

Background:

Isotretinoin is a synthetic analog of vitamin A. Recent studies support a role for retinoic acid in the recovery of olfactory function following injury in mice.

Objective:

This study aimed at determining the effect of isotretinoin on olfactory function in patients who have acne and are otherwise healthy.

Methods:

Forty-five patients (aged 25-40 years) with acne were included in the study. All patients underwent a rhinological examination. Olfactory function was assessed by the Sniffin' Sticks Test. The test was assessed at baseline and in the third month of isotretinoin treatment.

Results:

Isotretinoin improved the performance of patients in the olfactory test. The SST score increased from 8.7±1.09 to 9.5±1.19 (p<0.001), prevalence of hyposmia decreased from 40% to 24% and normosmia increased from 60% to 75% (p=0.059). The percentage of patients whose olfactory function was categorized as "good" increased from 6% to 21.3%. This increase was statistically significant (p<0.05).

Study limitations:

Absence of a control group is one of the limitations of this study. Also, we did not evaluate patients with smell test after stopping isotretinoin treatment.

Conclusion:

We examined the effect of systemic isotretinoin on olfactory function. It can be concluded from the present investigation that isotretinoin therapy improves the sense of smell.

Light and smell stimulus protocol reduced negative frontal EEG asymmetry and improved mood

Light and smell have both been shown to induce beneficial changes to human psychophysiology. Bright light therapy has been shown to have a positive impact on anxiety and depression and smell has also been shown to have positive effects on mood, stress, anxiety and depression. We developed a method for the delivery of integrated light and smell stimulation to try to optimise positive psychophysiological benefit. We tested its effectiveness on a physiological measure, EEG frontal alpha asymmetry (FA) and a psychological paradigm, the POMS test, both of which have been used as a measure of emotional state and mood. Light, pleasant smell, combined light+smell and a no stimulus control were delivered for 90s while the frontal alpha asymmetry (FA) was monitored. Smell and light+smell caused significant reductions in negative FA during stimulation. Exposure to a longer 15 min nonadaptive light+smell stimulus protocol reduced negative FA and decreased negative affect (POMS). The effects were greater in the negative FA group. Both the physiological (EEG) and psychometric (POMS) data indicate that integrated light and smell stimulation can reduce negative affect and reduce a marker for anxiety/ depression. This light+smell sensory stimulation protocol could offer a safe treatment for depression/anxiety.

Olfactory stimulatory with grapefruit and lavender oils change autonomic nerve activity and physiological function

This review summarizes the effects of olfactory stimulation with grapefruit and lavender oils on autonomic nerve activity and physiological function. Olfactory stimulation with the scent of grapefruit oil (GFO) increases the activity of sympathetic nerves that innervate white and brown adipose tissues, the adrenal glands, and the kidneys, decreases the activity of the gastric vagal nerve in rats and mice. This results in an increase in lipolysis, thermogenesis, and blood pressure, and a decrease in food intake. Olfactory stimulation with the scent of lavender oil (LVO) elicits the opposite changes in nerve activity and physiological variables. Olfactory stimulation with scent of limonene, a component of GFO, and linalool, a component of LVO, has similar effects to stimulation with GFO and LVO, respectively. The histamine H1-receptor antagonist, diphenhydramine, abolishes all GFO-induced changes in nerve activity and physiological variables, and the hitstamine H3-receptor antagonist, thioperamide, eliminates all LVO-induced changes. Lesions to the hypothalamic suprachiasmatic nucleus and anosmic treatment with ZnSO4 also abolish all GFO- and LVO-induced changes. These findings indicate that limonene and linalool might be the active substances in GFO and LVO, and suggest that the suprachiasmatic nucleus and histamine are involved in mediating the GFO- and LVO-induced changes in nerve activity and physiological variables.

Do ambient urban odors evoke basic emotions?

Fragrances, such as plant odors, have been shown to evoke autonomic response patterns associated with Ekman's (Ekman et al., 1983) basic emotions happiness, surprise, anger, fear, sadness, and disgust. Inducing positive emotions by odors in highly frequented public spaces could serve to improve the quality of life in urban environments. Thus, the present study evaluated the potency of ambient odors connoted with an urban environment to evoke basic emotions on an autonomic and cognitive response level. Synthetic mixtures representing the odors of disinfectant, candles/bees wax, summer air, burnt smell, vomit and musty smell as well as odorless water as a control were presented five times in random order to 30 healthy, non-smoking human subjects with intact sense of smell. Skin temperature, skin conductance, breathing rate, forearm muscle activity, blink rate, and heart rate were recorded simultaneously. Subjects rated the odors in terms of pleasantness, intensity and familiarity and gave verbal labels to each odor as well as cognitive associations with the basic emotions. The results showed that the amplitude of the skin conductance response (SCR) varied as a function of odor presentation. Burnt smell and vomit elicited significantly higher electrodermal responses than summer air. Also, a negative correlation was revealed between the amplitude of the SCR and hedonic odor valence indicating that the magnitude of the electrodermal response increased with odor unpleasantness. The analysis of the cognitive associations between odors and basic emotions showed that candles/bees wax and summer air were specifically associated with happiness whereas burnt smell and vomit were uniquely associated with disgust. Our findings suggest that city odors may evoke specific cognitive associations of basic emotions and that autonomic activity elicited by such odors is related to odor hedonics.

A Study on Olfactory Dysfunction in Turkish Population with using Survey Method and Validated Olfactory Testing

The aim of this study was to evaluate the effect of olfactory dysfunction on quality of life (QOL), and to investigate olfactory dysfunction related self-reported clinical features in Turkish population. The participants were questioned about the presence of any olfactory dysfunction. Participants with a complaint of olfactory dysfunction were asked to fill out a survey and then a validated olfactory test was performed. We asked 2,824 volunteers whether they had olfactory dysfunctions or not. A total of 199 (6.7 %) people mentioned that they had, and filled out the questions in our survey. The mean age of the surveyed population was 44 ± 15 years. The current investigation produced four major findings (1) the feeling of inadequacy due to olfactory dysfunction was more common among females than males (2) there was a significant correlation between subjective olfactory complaints and objective olfactory testing (3) problems in QOL issues are typically reported primarily in the areas of safety and nutrition (4) the possible reasons for the olfactory dysfunction according to the volunteers were upper respiratory infections including rhinosinusitis (46 %), allergic rhinitis (27 %), severe face and head trauma (6.5 %). The effect of subjective olfactory dysfunctions on QOL among the Turkish population was investigated for the first time. Problems in daily life issues are typically reported primarily in the areas of safety and nutrition.

The applicability of the "Sniffin' Sticks" olfactory test in a Turkish population

Background

Olfactory assessment is often neglected in clinical practice, although olfactory loss can assist in diagnosis and may lead to significant morbidity. “Sniffin’ Sticks” is a modern test of nasal chemosensory performance that was developed in Germany and validated in many countries. Our aim was to validate the applicability of “Sniffin’ Sticks” in a Turkish population.

Material/Methods

The study included 123 healthy volunteers with a reported normal sense of smell and 51 patients complaining of a reduction in their olfactory function presenting either at rhinology or neurology clinics. The mean age of the subjects tested was 30.2±12.5 years in 126 males and 48 females. The participants were divided into 2 groups according to subjective olfactory function – healthy or abnormal. Each subject’s olfactory function was assessed using the “Sniffin’ Sticks” test.

Results

We found significant differences in “Sniffin’ Sticks” test results between the abnormal and healthy groups. In healthy subjects, the 10^th percentiles of odor threshold score, odor discrimination score, odor identification score, and TDI score were 7.25, 12, 11, and 32, respectively. Considering the 2 groups together, apple and turpentine were the least well-recognized odors from the 16 odors presented.

Conclusions

Our study provides an update of normative values for routine clinical use of “Sniffin’ Sticks” in a Turkish population. Also, the present study validates that “Sniffin’ Sticks” olfactory test was applicable for clinical usage in a Turkish population.

A case series on the use of lavendula oil capsules in patients suffering from major depressive disorder and symptoms of psychomotor agitation, insomnia and anxiety

OBJECTIVE

Symptoms of agitation, anxiety and insomnia are frequent among patients with major depressive disorder (MDD) during the first weeks of psychiatric care. But a substantial number of patients declines taking pharmaceutical medication to avoid side effects. Therefore, an alternative herbal medication is needed. Clinical studies demonstrated that lavender oil capsules, termed Lasea®, have an anxiolytic effect comparable to Lorazepam and significantly reduce insomnia and agitation in non-depressed patients. Therefore, the aim of this retrospective case series was to analyze the effectiveness of Lasea® for patients with MDD and symptoms of anxiety, insomnia and psychomotor agitation.

DESIGN

Eight cases were analyzed retrospectively regarding the dosage, length of treatment, possible side effects and effectiveness of Lasea®.

SETTING

All cases were treated at the Department of Psychiatry at Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin in a naturalistic setting.

MAIN OUTCOME MEASURE

Effectiveness was measured by a change in the Hamilton Rating Scale for Depression (HAMD-17) total score and subscores.

RESULTS

In 6 cases, the combination of Lasea® and an antidepressant resulted in a reduction of MDD. Lasea® also reduced agitation in 6 cases. Psychological anxiety was reduced in 5, somatic anxiety in 4 cases whereas sleep-onset and sleep-maintenance insomnia improved in 3 cases each.

CONCLUSIONS

The results demonstrate that Lasea® reduces some of the anxiety related symptoms and sleep disturbances in MDD patients. Furthermore Lasea® significantly reduces psychomotor agitation. Additionally, the results indicate a significant global improvement stemming from the combinational therapy of Lasea® and antidepressant medication.

No effect of ambient odor on the affective appraisal of a desktop virtual environment with signs of disorder

Background

Desktop virtual environments (VEs) are increasingly deployed to study the effects of environmental qualities and interventions on human behavior and safety related concerns in built environments. For these applications it is essential that users appraise the affective qualities of the VE similar to those of its real world counterpart. Previous studies have shown that factors like simulated lighting, sound and dynamic elements all contribute to the affective appraisal of a desktop VE. Since ambient odor is known to affect the affective appraisal of real environments, and has been shown to increase the sense of presence in immersive VEs, it may also be an effective tool to tune the affective appraisal of desktop VEs. This study investigated if exposure to ambient odor can modulate the affective appraisal of a desktop VE with signs of public disorder.

Method

Participants explored a desktop VE representing a suburban neighborhood with signs of public disorder (neglect, vandalism and crime), while being exposed to either room air or subliminal levels of unpleasant (tar) or pleasant (cut grass) ambient odor. Whenever they encountered signs of disorder they reported their safety related concerns and associated affective feelings.

Results

Signs of crime in the desktop VE were associated with negative affective feelings and concerns for personal safety and personal property. However, there was no significant difference between reported safety related concerns and affective connotations in the control (no-odor) and in each of the two ambient odor conditions.

Conclusion

Ambient odor did not affect safety related concerns and affective connotations associated with signs of disorder in the desktop VE. Thus, semantic congruency between ambient odor and a desktop VE may not be sufficient to influence its affective appraisal, and a more realistic simulation in which simulated objects appear to emit scents may be required to achieve this goal.

Camphor--a fumigant during the Black Death and a coveted fragrant wood in ancient Egypt and Babylon--a review

The fragrant camphor tree (Cinnamomum camphora) and its products, such as camphor oil, have been coveted since ancient times. Having a rich history of traditional use, it was particularly used as a fumigant during the era of the Black Death and considered as a valuable ingredient in both perfume and embalming fluid. Camphor has been widely used as a fragrance in cosmetics, as a food flavourant, as a common ingredient in household cleaners, as well as in topically applied analgesics and rubefacients for the treatment of minor muscle aches and pains. Camphor, traditionally obtained through the distillation of the wood of the camphor tree, is a major essential oil component of many aromatic plant species, as it is biosynthetically synthesised; it can also be chemically synthesised using mainly turpentine as a starting material. Camphor exhibits a number of biological properties such as insecticidal, antimicrobial, antiviral, anticoccidial, anti-nociceptive, anticancer and antitussive activities, in addition to its use as a skin penetration enhancer. However, camphor is a very toxic substance and numerous cases of camphor poisoning have been documented. This review briefly summarises the uses and synthesis of camphor and discusses the biological properties and toxicity of this valuable molecule.

Phase II trial on the effects of Silexan in patients with neurasthenia, post-traumatic stress disorder or somatization disorder

Silexan, a novel lavender oil preparation for oral use, has been authorized in Germany for the treatment of states of restlessness during anxious mood. An open-label, exploratory trial was performed to assess the potential of the medicinal product in the treatment of restlessness caused by anxiety as related to several disorders. Outcome measures included the Symptom Checklist-90-Revised (SCL-90-R), von Zerssen's Depression Scale (D-S), the 36-item Short Form Health Survey Questionnaire (SF-36), and a sleep diary. 50 male and female patients with neurasthenia (ICD-10 F48.0), post-traumatic stress disorder (PSD; F43.1), or somatization disorder (F45.0, F45.1) were included to receive 1 × 80 mg/day Silexan over 6 weeks; 47 could be analyzed for efficacy as full analysis set. At baseline, patients suffered from restlessness (96%), depressed mood (98%), sleep disturbances (92%), or anxiety (72%). Of those, resp. 62%, resp. 57%, resp.51%, resp. 62% showed improvements during treatment (p < 0.001). For all patients, mean D-S score decreased by 32.7% and SCL-90-R Global Severity Index by 36.4% as compared to baseline, (p < 0.001), while the SF-36 Mental Health Score increased by 48.2% (p < 0.001). Waking-up frequency (p = 0.002), Waking-up duration (p < 0.001) and morning tiredness (p = 0.005) were reduced, while efficiency of sleep (p = 0.018) and mood (p = 0.03) improved. Patients suffering from neurasthenia or PSD showed comparable improvements with most outcomes. The results in this trial justify to further investigate Silexan in disorders with accompanying restlessness caused by sub-threshold anxiety. Adverse reactions, predominantly gastrointestinal complaints, were judged as mild or moderate.

Effects of Lavender Aroma on Sleep Quality in Healthy Japanese Students

This single-blind randomized study investigated the effectiveness of lavender aroma on quality of sleep in healthy Japanese students. The data of seven participants (2 men, 5 women) in the intervention group and eight participants (3 men, 5 women) in the control group were analyzed ( M age = 19.0 yr., SD = 0.9). The total procedure comprised 3 days for pre-intervention assessment, 5 days for the intervention, and 3 days for post-intervention assessment. Lavender exposure was compared with the absence of lavender (control). Information regarding the relaxing effect of aromas was provided to examine expectancy effects. Results showed that lavender aroma improved sleepiness at awakening after the intervention. Sex differences and daily variation in quality of sleep during the intervention period were not observed. The findings suggest that nighttime exposure to lavender aroma relieves sleepiness at awakening.

The embodiment of emotional feelings in the brain

Central to Walter Cannon's challenge to peripheral theories of emotion was that bodily arousal responses are too undifferentiated to account for the wealth of emotional feelings. Despite considerable evidence to the contrary, this remains widely accepted and for nearly a century has left the issue of whether visceral afferent signals are essential for emotional experience unresolved. Here we combine functional magnetic resonance imaging and multiorgan physiological recording to dissect experience of two distinct disgust forms and their relationship to peripheral and central physiological activity. We show that experience of core and body-boundary-violation disgust are dissociable in both peripheral autonomic and central neural responses and also that emotional experience specific to anterior insular activity encodes these different underlying patterns of peripheral physiological responses. These findings demonstrate that organ-specific physiological responses differentiate emotional feeling states and support the hypothesis that central representations of organism physiological homeostasis constitute a critical aspect of the neural basis of feelings.

A multi-center, double-blind, randomised study of the Lavender oil preparation Silexan in comparison to Lorazepam for generalized anxiety disorder

Generalized and persistent anxiety, accompanied by nervousness and other symptoms (Generalised Anxiety Disorder, GAD) is frequent in the general population and leads to benzodiazepine usage. Unfortunately, these substances induce sedation and have a high potential for drug abuse, and there is thus a need for alternatives. As the anxiolytic properties of lavender have already been demonstrated in pharmacological studies and small-scale clinical trials, it was postulated that lavender has a positive effect in GAD. A controlled clinical study was then performed to evaluate the efficacy of silexan, a new oral lavender oil capsule preparation, versus a benzodiazepine. In this study, the efficacy of a 6-week-intake of silexan compared to lorazepam was investigated in adults with GAD. The primary target variable was the change in the Hamilton Anxiety Rating Scale (HAM-A-total score) as an objective measurement of the severity of anxiety between baseline and week 6. The results suggest that silexan effectively ameliorates generalized anxiety comparable to a common benzodiazepine (lorazepam). The mean of the HAM-A-total score decreased clearly and to a similar extent in both groups (by 11.3+/-6.7 points (45%) in the silexan group and by 11.6+/-6.6 points (46%) in the lorazepam group, from 25+/-4 points at baseline in both groups). During the active treatment period, the two HAM-A subscores "somatic anxiety" (HAM-A subscore I) and "psychic anxiety" (HAM-A subscore II) also decreased clearly and to a similar extent in both groups. The changes in other subscores measured during the study, such as the SAS (Self-rating Anxiety Scale), PSWQ-PW (Penn State Worry Questionnaire), SF 36 Health survey Questionnaire and Clinical Global Impressions of severity of disorder (CGI item 1, CGI item 2, CGI item 3), and the results of the sleep diary demonstrated comparable positive effects of the two compounds. In conclusion, our results demonstrate that silexan is as effective as lorazepam in adults with GAD. The safety of silexan was also demonstrated. Since lavender oil showed no sedative effects in our study and has no potential for drug abuse, silexan appears to be an effective and well tolerated alternative to benzodiazepines for amelioration of generalised anxiety.

Cosmeceuticals and active ingredients

Cosmetic ingredients previously considered "inert" have potential to provide a biologic effect to skin. In a cosmeceutical formulation, the boundary between an "active" and "inert" ingredient may be obscured. For this reason, the cosmeceutical distributor must find a nonambiguous method to demonstrate the efficacy of a new ingredient. For a product to be successful in the marketplace, the benefits of the product must clearly be communicated to the consumer, and the consumer must be satisfied with product performance.

Influences of olfactory impairment on depression, cognitive performance, and quality of life in Korean elderly

Despite high prevalence of olfactory loss in the elderly, this is typically overlooked. The aim of this study was to examine the impact of olfactory loss on depression, cognitive performance, and quality of life (QoL) in the general population of South Korea, and also to investigate the association between the above variables. A total of 127 Korean elderly aged from 65 to 89 years participated in this study. Olfactory sensitivity, depression, cognitive performance, and QoL were assessed with T&T olfactometry, the Geriatric Depression Scale, Mini-Mental State Examination, and a questionnaire for Geriatric Quality of Life, respectively. Subjects with severely impaired olfactory function showed a significantly higher degree of depression, lower cognitive performance, and decreased QoL compared to subjects with normal to moderately impaired olfaction. However, when controlling for cognitive performance, the olfactory sensitivity was not correlated with degrees of depression and QoL. In conclusion, our findings confirm the relationships of olfactory loss with depression, cognitive performance, and QoL; they also indicate that tests of olfactory function could be used in the screening for cognitive impairment.

The Use of Semantic Differential Scaling to Define the Multi-Dimensional Representation of Odors

The mental representation elicited by smelling an odor often consists of multiple sensory and affective dimensions, yet, the richness of this elaboration is difficult to capture using methods to rate the intensity of these factors in isolation. Attempts to use language descriptors for olfactory experience have also been shown to be rather limited; among non-specialists, there is no universally accepted system for describing odors, leading to greater reliance on specific item associations. In this study we explored the utility of semantic differential scaling for illustrating the various dimensions of olfactory experience. 300 volunteers rated thirty distinct odorants using 50 SDS adjectives. Three factors emerged from the analysis (based on 17 adjective-pairs) accounting for 53% of the variance, and corresponding to the evaluation, potency and activity dimensions identified for other stimulus types. SD scaling appears to be a viable method for identifying the multiple dimensions of mental representation evoked when smelling an odorant and may prove a useful tool for both consumer and basic research alike. PRACTICAL APPLICATIONS: Although numerous methods of classifying odors have been developed, little agreement has been achieved on the dimensions that are useful to both basic and consumer research. The identification of a set of Semantic Differential adjectives which are relevant to olfactory experience can become a useful tool for classifying the qualitative and affective basis on which odorants differ.. In particular, the degree to which odorants evokes multi-dimensional representations from other sensory modalities (visual, auditory, somatosensory or gustatory), can be usefully applied in the arena of product development both within and across cultures.

Complaints of olfactory disorders: epidemiology, assessment and clinical implications

PURPOSE OF REVIEW

Recent studies illuminate the difficulties that patients with olfactory disorder face in daily life, which underlines the need to understand its prevalence, and to diagnose and treat these patients. The purpose of the present review is to characterize olfactory disorders and describe associated complaints, present recent insights into epidemiology, suggest procedures to assess these disorders, and discuss clinical implications.

RECENT FINDINGS

A compilation of previous and new studies of olfactory disorders suggests associated complaints of poor quality of life, depression, and various specific consequences. Epidemiological studies show that loss in odor sensitivity is common in both general and clinical populations, whereas dysosmia is less common in general populations but frequent in clinical populations. The most common etiologies are post-upper respiratory infection, nasal/sinus disease and head trauma.

SUMMARY

Procedures to diagnose olfactory disorders and to identify etiologies are available. Depending on etiology, certain types of treatment are often successful, such as endoscopic sinus surgery and corticosteroid administration in nasal/sinus disease. In post-upper respiratory infection and head trauma, spontaneous recovery is fairly high. In any case, it is advisable to counsel the patient with regards to strategies to cope with olfactory disorders.

Smell, Odor, and Somatic Work: Sense-Making and Sensory Management

Sensation (noun) is emergent in joint acts of sensing (verb). To sense, in other words, is to make sense, and sense making entails what we call “somatic work.” We investigate these dynamics in the context of olfaction, highlighting how olfaction intersects with social, cultural, and moral order—thus compelling reflexive forms of somatic work by which people manage smell (as an act) and odor (as a sign). Our data are drawn from a convenience sample of twenty-three participants who reflected on their olfactory experiences through the use of research journals. We focus on three central dynamics: participants'attribution of meaning to odors, the somatic rules that structure perception, and olfactory facework. The participants in this study attribute meaning to odor through odiferous indexes that intersect with an individual's somatic career; olfactory somatic rules entail disciplined somatic work in relation to the intensity of odor, its context, and moral/aesthetic character. Because odor conveys meaning, it is part of the ritualized facework of everyday life. Odor is a subtle but significant component of the culturally normative and aesthetic rituals of expressive and impressive everyday life.

Effects of direct cedrol inhalation into the lower airway on autonomic nervous activity in totally laryngectomized subjects

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

Relationships between smell sensation and autonomic changes have been studied extensively. However, the possibility that odorants may also act on the lung and lower airway remains unknown.

WHAT THIS STUDY ADDS

The present results provide the first evidence that the lung and lower airway exert an inhibitory influence on the cardiovascular system in response to Cedrol (odorant) in the air under physiological conditions.

AIMS

Previous studies reported that Cedrol (odorant) inhalation (CI) induced changes in autonomic balance and baroreceptor sensitivity (BRS) in both healthy subjects and anosmic patients. This suggests that Cedrol may act on the lower airway, and that the pulmonary system may exert an inhibitory influence on the cardiovascular system.

METHOD

To test the above possibility, vaporized Cedrol (64.0 +/- 7.7 10(-9)m) or blank air was directly inhaled through the lower airway from a hole in the trachea, but not through the upper airway, using totally laryngectomized subjects. During the experiment, ECG, systolic (SBP) and diastolic (DBP) blood pressures were measured. Sympathetic and parasympathetic nervous activity was estimated by spectral analyses of variability in these parameters (heart rate variability (HRV), SBP variability (SBPV) and DBP variability (DBPV)). BRS was computed from transfer gain between SBP and the R-R interval of the ECG.

RESULTS

SBP and DBP significantly decreased during CI, although there were no significant differences in HR and respiratory rate. BRS significantly increased during CI. The low frequency components of SBPV and DBPV (indices for sympathetic activity) significantly decreased during CI, while high frequency components of HRV (an index for parasympathetic activity) significantly increased.

CONCLUSIONS

The present experiment using totally laryngectomized patients replicated the similar results in healthy subjects who inhaled Cedrol through the nose, suppression of sympathetic outflow and increase in parasympathetic outflow. These results demonstrated that Cedrol acts on the lower airway and pulmonary system, and suggest a new target for drug therapy of hypertension.

Autonomic nervous system responses to sweet taste: evidence for habituation rather than pleasure

Previous recordings of the variations of autonomic nervous system (ANS) parameters associated with each primary taste (sweet, salty, sour and bitter) showed that sweet taste induced very weak ANS responses, in the same range or weaker than responses evoked by mineral water. The purpose of this study was then to determine whether this weak ANS activation reflects the pleasant hedonic valence of sweet or the habituation of the organism to this innate-accepted taste. Twenty healthy volunteer subjects (8 males and 12 females, mean age=22.85 years) participated in the experiment. Taste stimuli were a solution of 0.3 M sucrose and three sweet flavours (orange juice, coke, lemonade) as "pleasant" sweet stimuli, and a solution of 0.15 M NaCl as an "unpleasant" stimulus. "Evian" mineral water served as the diluent and as a neutral stimulus. Throughout the test, five ANS parameters (skin potential and skin resistance, skin blood flow and skin temperature, instantaneous heart rate) were simultaneously and continuously recorded. After they had tasted each solution, subjects filled out a questionnaire in which they had to evaluate the hedonic dimension and the sweet intensity of each gustative stimulus. The lack of correlation between the mean hedonic scores associated with the four sweet stimuli and the mean values of the autonomic parameter variations tends to indicate that the weak ANS responses induced by the sweet gustative stimuli rather reflect the habituation of the organism to sweet taste than a gradation in sensory pleasure.

Odor annoyance of environmental chemicals: sensory and cognitive influences

In low concentrations, environment pollutants like volatile organic compounds (VOCs) may be perceived via olfaction. Modulators of odor-mediated health effects include age, gender, or personality traits related to chemical sensitivity. Severe multi-organ symptoms in response to odors also characterize a syndrome referred to as idiopathic environmental intolerance (IEI). One prominent feature of IEI is self-reported odor hypersensitivity that is usually not accompanied by enhanced olfactory functioning. The impact of interindividual differences in olfactory functioning on chemosensory perceptions is sparsely investigated, and therefore this study addressed the influences of different types of modulators, including olfactory functioning. In a psychophysical scaling experiment, an age-stratified sample of 44 males and females was examined. After controlled application of nine concentrations of six chemicals by flow-olfactometry, the participants rated four olfactory and nine trigeminal perceptions. Weak effects were found for gender and age, as well as some modulating effects of self-reported chemical sensitivity and odor discrimination ability. For chemical sensitivity, the results were as expected: Subjects with higher sensitivity reported stronger perceptions. The individual odor threshold (n-butanol) exerted no influence on the subjects' ratings of olfactory and trigeminal perceptions. Surprisingly, above-average odor discrimination ability was associated with lower ratings of odor intensity and nausea. This particular aspect of olfactory functioning might be a reflection of a more objective odor evaluation model buffering emotional responses to environmental odors.

The sense of smell, its signalling pathways, and the dichotomy of cilia and microvilli in olfactory sensory cells

Smell is often regarded as an ancillary perception in primates, who seem so dominated by their sense of vision. In this paper, we will portray some aspects of the significance of olfaction to human life and speculate on what evolutionary factors contribute to keeping it alive. We then outline the functional architecture of olfactory sensory neurons and their signal transduction pathways, which are the primary detectors that render olfactory perception possible. Throughout the phylogenetic tree, olfactory neurons, at their apical tip, are either decorated with cilia or with microvilli. The significance of this dichotomy is unknown. It is generally assumed that mammalian olfactory neurons are of the ciliary type only. The existence of so-called olfactory microvillar cells in mammals, however, is well documented, but their nature remains unclear and their function orphaned. This paper discusses the possibility, that in the main olfactory epithelium of mammals ciliated and microvillar sensory cells exist concurrently. We review evidence related to this hypothesis and ask, what function olfactory microvillar cells might have and what signalling mechanisms they use.

Aromatherapy in the management of psychiatric disorders: clinical and neuropharmacological perspectives

Aromatherapy is currently used worldwide in the management of chronic pain, depression, anxiety, some cognitive disorders, insomnia and stress-related disorders. Although essential oils have been used, reputedly effectively, for centuries as a traditional medicine, there is very little verified science behind this use. The pharmacology of the essential oils and/or their single chemical constituents, therefore, remains largely undiscovered. However, accumulating evidence that inhaled or dermally applied essential oils enter the blood stream and, in relevant molecular, cellular or animal models, exert measurable psychological effects, indicates that the effects are primarily pharmacological.This review includes evidence from the limited number of clinical trials that have been published of 'psychoaromatherapy' in relation to psychiatric disorders, together with evidence from mechanistic, neuropharmacological studies of the effects of essential oils in relevant in vitro and in vivo models. It is concluded that aromatherapy provides a potentially effective treatment for a range of psychiatric disorders. In addition, taking into account the available information on safety, aromatherapy appears to be without the adverse effects of many conventional psychotropic drugs. Investment in further clinical and scientific research is clearly warranted.

Blood-injury phobia with and without a history of fainting: disgust sensitivity does not explain the fainting response

OBJECTIVE

Individuals diagnosed with blood-injury phobia respond to venipuncture with strong psychophysiological responses. We investigated whether disgust sensitivity contributes to the fainting response and is associated with parasympathetic activation, as suggested by previous research.

METHODS

Twenty individuals diagnosed with blood-injury phobia (9 with a history of fainting to the sight of blood, 11 without such a fainting history) and 20 healthy controls were compared. Psychophysiological responses and self-report measures of anxiety, disgust, and embarrassment were monitored during rest, a paced breathing task, and venipuncture. In addition, trait disgust sensitivity and blood-injury fears were assessed.

RESULTS

Blood-injury phobics reported enhanced anxiety, disgust, and embarrassment during venipuncture. They also experienced heightened arousal, as indicated by heart rate, respiration rate, and minute ventilation. Blood-injury phobics without a fainting history tended toward higher anxiety and disgust scores. There was no evidence for increased parasympathetic activation in either blood-injury phobic subgroup or of an association of disgust and parasympathetic activation.

CONCLUSION

The tendency to faint when exposed to blood-injury stimuli may suffice as a conditioning event leading into phobia, without specific involvement of disgust sensitivity and parasympathetic activation.

Basic emotions are associated with distinct patterns of cardiorespiratory activity

The existence of specific somatic states associated with different emotions remains controversial. In this study, we investigated the profile of cardiorespiratory activity during the experience of fear, anger, sadness and happiness. ECG and respiratory activity was recorded in 43 healthy volunteers during the recall and experiential reliving of one or two potent emotional autobiographical episodes and a neutral episode. Univariate statistics indicated that the four emotions differed from each other and from the neutral control condition on several linear and spectral indices of cardiorespiratory activity. Dependent variables were further reduced to five physiologically meaningful factors using an exploratory principal component analysis (PCA). Multivariate analyses of variance and effect size estimates calculated on those factors confirmed the differences between the four emotion conditions. A stepwise discriminant analyses predicting emotions using the PCA factors led to a classification rate of 65.3% for the four emotions (chance=25%; p=0.001) and of 72.0-83.3% for pair-wise discrimination (chance=50%; p's<0.05). These findings may be considered preliminary in view of the small sample on which the multivariate approach has been applied. However, this study emphasizes the need to better characterize the multidimensional factors involved in cardio-respiratory regulation during emotion. These results are consistent with the notion that distinct patterns of peripheral physiological activity are associated with different emotions.

Effectiveness of Aroma on Work Efficiency: Lavender Aroma during Recesses Prevents Deterioration of Work Performance

The present study investigated whether exposure to aromas during recess periods affects work performance. Subjects comprised 36 healthy male students (mean age, 24.2 +/- 2.2 years) who were randomly divided into three groups: (1) control group, not exposed to aroma during recesses; (2) jasmine group, exposed to jasmine aroma during recesses; and (3) lavender group, exposed to lavender aroma during recesses. All participants completed five work sessions performing a task requiring concentration on a computer monitor, with each session lasting 60 min. Recess periods of 30 min were provided between each session. To clarify the time at which work concentration was lowest, work performance for the control group was analyzed. Concentration was lowest in the afternoon period, where afternoon drowsiness is strongest. Comparison of the three groups for this time period indicated significantly higher concentration levels for the lavender group than for the control group. No such effect was noted for the jasmine group. Although lavender is a sedative-type aroma, use during recess periods after accumulation of fatigue seems to prevent deterioration of performance in subsequent work sessions.

A stimulation method using odors suitable for PET and fMRI studies with recording of physiological and behavioral signals

A design for a semi-automatic olfactometric system is described for PET and fMRI experiments. The olfactometer presents several advantages because it enables the use of an 'infinite' number of odorants and the synchronization of stimuli with breathing. These advantages mean that the subject is recorded while breathing normally during olfactory judgment tasks. In addition, the design includes a system for recording the behavioral (rating scale) and physiological (breathing, electrodermal reaction (ED), plethysmography (PL)) signals given by the subject. Both systems present the advantage of being compatible with fMRI magnetic fields since no ferrous material is used in the Faraday cage and signals are transmitted via an optical transmission interface to an acquisition system.

Taste modulation of nociception differently affects chronically stressed rats

Stress responses cover a wide range of physiological changes, including alterations in the perception of and response to pain. Animals submitted to repeated stress present altered nociception and this effect is part of this process of adaptation; in addition pleasant and unpleasant experiences with tastes and odors have been shown to affect distinct behavioral aspects, such as pain perception. The aim of the present study is to verify the responses of repeatedly stressed rats (1 h of daily immobilization during 40 days) to pleasant and unpleasant tastes on nociception, when compared to control animals. An increase in the tail-flick latency (TFL) was observed 5 min after exposure to a sweet taste in the control group, whereas no effect was observed in chronically stressed animals. When submitted to an unpleasant taste (5% acetic acid), the chronically stressed group presented an increase in TFL, whereas no effect was observed in the control group. In conclusion, chronically stressed animals present different nociceptive responses to sweet and acid tastes; although control animals suitably respond to a sweet stimulus, stressed animals seem to be more apt to react to the unpleasant stimulus.

fMRI of emotional responses to odors: influence of hedonic valence and judgment, handedness, and gender

Previous positron emission tomography studies of right-handed individuals show that the left orbitofrontal cortex is dominant during emotional processing of odors. We collected functional magnetic resonance imaging data from 28 subjects to study this network as a function of odor hedonic valence (pleasant vs. unpleasant), active hedonic judgments versus passive sensation of hedonically charged odors, handedness, and gender. Two functional runs were performed, with pleasant and unpleasant odors presented in different epochs. In the first run, subjects passively smelled odorants, whereas in the second run they rated degree of odor pleasantness or unpleasantness by using a "finger-span" technique that simulated a visual rating scale. Electrodermal and plethysmography responses were simultaneously recorded to control for covert, physiological manifestations of the emotional response. The piriform-amygdala area and ventral insula were activated more for unpleasant than pleasant odors. More extreme ratings were also associated with higher electrodermal amplitude, suggesting that activation stemmed more from emotional or hedonic intensity than valence, and that unpleasant odors induced more arousal than pleasant odors. Unpleasant odors activated the left ventral insula in right-handers and the right ventral insula in left-handers, suggesting lateralized processing of emotional odors as a function of handedness. Active decisions about odor pleasantness induced specific left orbitofrontal cortex activation, implicating the role of this area in the conscious assessment of the emotional quality of odors. Finally, left orbitofrontal cortex was more active in women than men, potentially in relation to women's well-documented advantage in odor identification.