Pregnant women exhibit decreased trigeminal sensitivity.

INTRODUCTION: Chemosensory function in pregnant women is far from being fully understood due to the lack of data and inconsistencies between the results of self-reports and objective studies. METHODS: In the present study in pregnant and non-pregnant women (npregnant = 14, nnon-pregnant = 13), we measured EEG-derived electrophysiological response measures supported by psychophysical olfactory and trigeminal tests. RESULTS: Results indicate that the olfactory event-related potential amplitudes or latencies of the P1, N1, and P2 components remain unchanged in pregnant women. In accordance with these findings, no difference was observed between pregnant and non-pregnant women in psychophysical olfactory tests. However, pregnant women displayed a lower degree of sensitivity to trigeminal stimuli compared to non-pregnant controls, which was also reflected in the electrophysiological responses to trigeminal stimuli. CONCLUSION: Counterintuitive as they may seem, our findings demonstrate a "flattening" of chemosomatosensory responses. Psychological processes occurring during pregnancy, such as changes in socioemotional perception of odors resulting from the diminished stress response, may provide a background to these results. Overall, the present results indicate the absence of major differences between non-pregnant and pregnant women in terms of measured olfactory function though chemosomatosensory function of the pregnant women appears to be decreased.

Gender differences in the relationship between neuroticism and odor memory.

Given the indications on the relationship between neuroticism and various olfactory functions as well as the emotionality of odor memory, it is surprising that no research so far has investigated whether neuroticism corresponds with odor memory performance. Thus, the purpose of our study was to address this question in the context of gender differences. Participants (73 men) completed the 60-items NEO Five Factor Inventory and participated in 32-items "Test for odor memory". In the separate analyses conducted for men and women, we demonstrated that women outperformed men regarding the number of correct odor recognitions in the odor memory test and had higher neuroticism level than men. Spearman correlation showed further that neuroticism was positively associated with D-prime (R = 0.3, p = .021) and the number of correct odor recognitions in women (R = 0.32, p = .014). This effect was, respectively, moderately (B10 = 5.2) and strongly confirmed using the Bayesian approach (B10 = 8). However, Bonferroni post-hoc correction for multiple comparisons further revealed that in case of neuroticism and the number of hits, as well as D-prime, alpha level was below significance, indicated by p = .006. The correlation between neuroticism level and odor memory performance was significantly higher in women compared to men (Z = 1.8, p = .038), while in case of neuroticism and D-prime, it was on a trend level (Z = 1.5, p = .074). Overall, the present results indicate that neuroticism might be linked to conscious odors' remembering for women, which can be explained by the warning role of odor memory and its connection to limbic structures, as well as by the higher level of neuroticism and odor memory performance in women compared to men.

Olfaction evaluation in dogs with sudden acquired retinal degeneration syndrome.

PURPOSE: To evaluate olfaction in dogs with sudden acquired retinal degeneration syndrome (SARDS) compared with sighted dogs and blind dogs without SARDS as control groups. ANIMALS STUDIED: Forty client-owned dogs. PROCEDURE: Olfactory threshold testing was performed on three groups: SARDS, sighted, and blind/non-SARDS using eugenol as the test odorant. The olfactory threshold was determined when subjects indicated the detection of a specific eugenol concentration with behavioral responses. Olfactory threshold, age, body weight, and environmental room factors were evaluated. RESULTS: Sixteen dogs with SARDS, 12 sighted dogs, and 12 blind/non-SARDS dogs demonstrated mean olfactory threshold pen numbers of 2.8 (SD = 1.4), 13.8 (SD = 1.4), and 13.4 (SD = 1.1), respectively, which correspond to actual mean concentrations of 0.017 g/mL, 1.7 × 10-13 g/mL and 4.26 × 10-13 g/mL, respectively. Dogs with SARDS had significantly poorer olfactory threshold scores compared with the two control groups (p < .001), with no difference between the control groups (p = .5). Age, weight, and room environment did not differ between the three groups. CONCLUSIONS: Dogs with SARDS have severely decreased olfaction capabilities compared with sighted dogs and blind/non-SARDS dogs. This finding supports the suspicion that SARDS is a systemic disease causing blindness, endocrinopathy, and hyposmia. Since the molecular pathways are similar in photoreceptors, olfactory receptors, and steroidogenesis with all using G-protein coupled receptors in the cell membrane, the cause of SARDS may exist at the G-protein associated interactions with intracellular cyclic nucleotides. Further investigations into G-protein coupled receptors pathway and canine olfactory receptor genes in SARDS patients may be valuable in revealing the cause of SARDS.

Mood Impairment in Patients with Olfactory Loss Predicts a More Pronounced Recovery of Olfactory Function.

BACKGROUND: Here, we refer to our publication "Symptoms of depression change with olfactory function" [Sci Rep. 2022 Apr 5;12(1):5656]. OBJECTIVES: Depression decreases with olfactory improvement, but the question remains open of whether patients who indicate more suffering regarding mood impairment exhibit a different pattern of recovery from olfactory loss compared to those who suffer less. METHOD: In the course of an additional investigation of our previously published dataset, we established groups of participants (N = 171) with low (≤8 points on a depression [ADSL] scale; 47%; n = 45) and high (≥14 points on ADSL scale; 53%; n = 53) mood impairment. RESULTS: We found that the group that reported more sufferance on a depression [ADSL] scale improved more in change of olfactory function, and, more importantly, odor discrimination change over a period of an average of 11 months. CONCLUSION: Patients, who suffered more, as indicated by higher scores on ADSL scale, may have been more willing to commit to the study protocol, and thus their improvement was more notable.

Depression Severity Is Different in Dysosmic Patients Who Have Experienced Traumatic Brain Injury Compared with Those Who Have Not.

Traumatic brain injury (TBI) in humans can result in olfactory, cognitive, and affective changes. Surprisingly, research on the consequences of TBI often did not control for olfactory function in the investigated groups. Consequently, the affective or cognitive differences might be misleading as related rather to different olfactory performance than to a TBI experience. Hence, our study aimed to investigate whether TBI occurrence would lead to altered affective and cognitive functioning in two groups of dysosmic patients, one with TBI experience and one without. In total, 51 patients with TBI experience and 50 controls with varied causes of olfactory loss were thoroughly examined in terms of olfactory, cognitive, and affective performance. Student t-tests demonstrated that the only significant difference between the groups appeared in the depression severity, with TBI patients being more depressed (t = 2.3, p = 0.011, Cohen's d = -0.47). Regression analyses further showed that TBI experience was significantly associated with depression severity (R2 = 0.05, F [1, 96] = 5.5, p = 0.021, beta = 1.4). In conclusion, the present study showed that TBI experience is linked to depression, which is more pronounced compared to individuals with olfactory loss without TBI.

Odor Threshold Differs for Some But Not All Odorants Between Older and Younger Adults.

OBJECTIVES: Olfactory function deteriorates with age, and definitive mechanisms by which this decline occurs are likely multifactorial. The present study, conducted on a large cohort of healthy participants, aimed to investigate whether odor thresholds would differ for variable odors with different physicochemical (e.g., heavy- vs lightweight molecules) and perceptual characteristics. METHODS: In 81 participants (51%, ≥50 years old), we assessed odor threshold in 2 sessions. RESULTS: Linear mixed-model analyses revealed that odor thresholds in younger and older adults changed with different odor conditions, presumably due to the common exposition to some of the odors, their trigeminality, and lipophilicity. This effect was observed for piperine, eucalyptol, 2-nonanone, gamma-valerolactone, and pinene-alpha, but not for the other 15 odorants studied. Furthermore, suprathreshold perception, that is, intensity and, to some extent, irritation, contributed independently to sensorial odor threshold, the latter ones particularly in older adults. We also found that the molecular weight of the odorants did not add to their threshold by, respectively, younger and older adults. DISCUSSION: To conclude, the present findings are in line with previous studies showing that the age-related change of chemosensory abilities is a multifaceted phenomenon, which does not affect all odorants.

Effects of odors on sleep quality in 139 healthy participants.

The present study aimed to systematically examine whether laurinal, orange odor, and a specifically designed "perfume" influence sleep quality. During sleep, healthy participants (n = 139) were presented with odor or no odor through nose clips for fourteen consecutive nights (phase one). We collected physiological parameters together with subjective reports. Later on, longer lasting effects of this manipulation were examined for the following fourteen nights (phase two) without exposition to odors. Additionally, olfactory, cognitive and non-cognitive measures were conducted before phase one, between both phases and after phase two. One-way analyses of variance for repeated measures with nights and condition (1 vs 2) as the within-subject factor and odor condition (0, 1, 2 or 3) together with odor pleasantness rating as between-subject factor, was employed to analyse data. Overall, the present results demonstrated that the odor condition in comparison to control had no consistent effect on sleep in healthy participants which can be possibly explained by exposure to odors via nose clips. However, the analyses indicated that the individual pleasantness of odors enhanced the positive assessment of sleep quality. Altogether, the present results indicate that the subjective perception of an odor's hedonic value appears to be crucial for sleep quality, not the odors themselves.

Do Voice-Based Judgments of Socially Relevant Speaker Traits Differ Across Speech Types?

PURPOSE: The human voice is a powerful and evolved social tool, with hundreds of studies showing that nonverbal vocal parameters robustly influence listeners' perceptions of socially meaningful speaker traits, ranging from perceived gender and age to attractiveness and trustworthiness. However, these studies have utilized a wide variety of voice stimuli to measure listeners' voice-based judgments of these traits. Here, in the largest scale study known to date, we test whether listeners judge the same unseen speakers differently depending on the complexity of the neutral speech stimulus, from single vowel sounds to a full paragraph. METHOD: In a playback experiment testing 2,618 listeners, we examine whether commonly studied voice-based judgments of attractiveness, trustworthiness, dominance, likability, femininity/masculinity, and health differ if listeners hear isolated vowels, a series of vowels, single words, single sentences (greeting), counting from 1 to 10, or a full paragraph recited aloud (Rainbow Passage), recorded from the same 208 men and women. Data were collected using a custom-designed interface in which vocalizers and traits were randomly assigned to raters. RESULTS: Linear-mixed models show that the type of voice stimulus does indeed consistently affect listeners' judgments. Overall, ratings of attractiveness, trustworthiness, dominance, likability, health, masculinity among men, and femininity among women increase as speech duration increases. At the same time, speaker-level regression analyses show that interindividual differences in perceived speaker traits are largely preserved across voice stimuli, especially among those of a similar duration. CONCLUSIONS: Socially relevant perceptions of speakers are not wholly changed but rather moderated by the length of their speech. Indeed, the same vocalizer is perceived in a similar way regardless of which neutral statements they speak, with the caveat that longer utterances explain the most shared variance in listeners' judgments and elicit the highest ratings on all traits, possibly by providing additional nonverbal information to listeners. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.21158890.

Factors Associated With Highest Symptoms of Anxiety During COVID-19: Cross-Cultural Study of 23 Countries.

The COVID-19 restrictions have impacted people's lifestyles in all spheres (social, psychological, political, economic, and others). This study explored which factors affected the level of anxiety during the time of the first wave of COVID-19 and subsequent quarantine in a substantial proportion of 23 countries, included in this study. The data was collected from May to August 2020 (5 June 2020). The sample included 15,375 participants from 23 countries: (seven from Europe: Belarus, Bulgaria, Croatia, Hungary, Italy, Romania, Russia; 11 from West, South and Southeast Asia: Armenia, India, Indonesia, Iran, Iraq, Jordan, Malaysia, Pakistan, Saudi Arabia, Thailand, Turkey; two African: Nigeria and Tanzania; and three from North, South, and Central America: Brazil, Canada, United States). Level of anxiety was measured by means of the 7-item Generalized Anxiety Disorder Scale (GAD-7) and the 20-item first part of The State-Trait Anxiety Inventory (STAI)-State Anxiety Inventory (SAI). Respondents were also asked about their personal experiences with COVID-19, attitudes toward measures introduced by governments, changes in attitudes toward migrants during a pandemic, family income, isolation conditions, etc. The factor analysis revealed that four factors explained 45.08% of variance in increase of anxiety, and these components were interpreted as follows: (1) personal awareness of the threat of COVID-19, (2) personal reaction toward officially undertaken measures and attitudes to foreigners, (3) personal trust in official sources, (4) personal experience with COVID-19. Three out of four factors demonstrated strong associations with both scales of anxiety: high level of anxiety was significantly correlated with high level of personal awareness of the threat of COVID-19, low level of personal reaction toward officially undertaken measures and attitudes to foreigners, and high level of presence of personal experience with COVID-19. Our study revealed significant main effects of sex, country, and all four factors on the level of anxiety. It was demonstrated that countries with higher levels of anxiety assessed the real danger of a pandemic as higher, and had more personal experience with COVID-19. Respondents who trusted the government demonstrated lower levels of anxiety. Finally, foreigners were perceived as the cause of epidemic spread.

Can Humans Discriminate Horse 'Fear' Chemosignals from Control Chemosignals? Comment on Sabiniewicz et al. A Preliminary Investigation of Interspecific Chemosensory Communication of Emotions: Can Humans (Homo sapiens) Recognise Fear- and Non-Fear Body Odour from Horses (Equus ferus caballus). Animals 2021, 11, 3499.

We illustrate the problematic nature of different assumptions guiding the examination of whether humans can detect the source of fear chemosignals (i.e., body odors) emitted by horses-a research question examined in an article recently published in Animals. A central issue is that the formulation of the question itself contains the answer to it. In this paper, we parse the problematic assumptions on which the analysis and methodology rely, leading to conclusions that are difficult to support. These assumptions constitute examples of methodological problems that should be avoided in research with animals and odors. The unique aspect of this paper is that it is a collaborative product, including the original contributor, in the pursuit of transparency in science.

Reply to Semin et al. Can Humans Discriminate Horse 'Fear' Chemosignals from Control Chemosignals? Comment on "Sabiniewicz et al. A Preliminary Investigation of Interspecific Chemosensory Communication of Emotions: Can Humans (Homo sapiens) Recognise Fear- and Non-Fear Body Odour from Horses (Equus ferus caballus). Animals 2021, 11, 3499".

Whereas several recent studies demonstrated that some animal species are able to recognize human emotions based on information from body odor [...].

Symptoms of depression change with olfactory function.

Olfactory loss is associated with symptoms of depression. The present study, conducted on a large cohort of mostly dysosmic patients, aimed to investigate whether improvement in olfactory performance would correspond with a decrease in depression severity. In 171 participants (157 dysosmic), we assessed olfactory function and severity of depression before and after an average interval of 11 months, with many patients showing improvement in olfactory function. Separate analyses were conducted for (a) the whole group of patients and (b) the group of dysosmic patients using both classic and Bayesian approaches. For odor identification, Student t test demonstrated that the whole sample improved consistently, especially within the group of dysosmic patients. The dysosmic group also improved in odor threshold and overall olfactory function. Pearson correlation showed that an increase in olfactory function was associated with a decrease in depression severity, particularly in dysosmic patients. To conclude, the present results indicate that symptoms of depression change with olfactory function in general and odor identification in particular.

A Preliminary Investigation of Interspecific Chemosensory Communication of Emotions: Can Humans (Homo sapiens) Recognise Fear- and Non-Fear Body Odour from Horses (Equus ferus caballus).

Mammalian body odour conveys cues about an individual's emotional state that can be recognised by conspecifics. Thus far, little attention has been paid to interspecific odour communication of emotions, and no studies have examined whether humans are able to recognise animal emotions from body odour. Thus, the aim of the present study was to address this question. Body odour samples were collected from 16 two-year-old thoroughbred horses in fear and non-fear situations, respectively. The horse odour samples were then assessed by 73 human odour raters. We found that humans, as a group, were able to correctly assign whether horse odour samples were collected under a fear- or a non-fear condition, respectively. Furthermore, they perceived the body odour of horses collected under the fear condition as more intense, compared with the non-fear condition. An open question remains, which is whether humans could simply distinguish between little versus much sweat and between high intensity versus low intensity or were able to recognise horses' fear and non-fear emotions. These results appear to fit the notion that the ability to recognise emotions in other species may present an advantage to both the sender and the receiver of emotional cues, particularly in the interaction between humans and domesticated animals. To conclude, the present results indicate that olfaction might contribute to the human recognition of horse emotions. However, these results should be addressed with caution in light of the study's limitations and only viewed as exploratory for future studies.

No evidence for association between human body odor quality and immune system functioning.

Previous studies have shown that women perceive male faces with a more reactive immune system as more attractive, but whether body odor might likewise provide cues to immune function has not been investigated yet. These two studies tested a possible relationship between body odor quality and immunoreactivity (Study 1) and immune system function (Study 2). In Study 1, we collected body odor samples from 21 men just before and two weeks after vaccination against hepatitis A/B and meningococcus. We determined the levels of specific antibodies (selected as markers of immune system's reactivity), testosterone, and cortisol. Subsequently, 88 female raters assessed the odor samples for their attractiveness, intensity, and healthiness. In Study 2, we collected body odor and blood samples from 35 men and women. We assessed key parameters of their innate and adaptive immunity, such as complement activity or total lymphocyte T and B counts and asked 95 raters to assess the odor samples for their attractiveness, intensity, and healthiness. In Study 1, we found no significant association between antibody levels induced by vaccination and perceived body odor attractiveness, intensity, and healthiness. We also found no significant relationship between antibody levels and steroid hormones (testosterone and cortisol). In Study 2, we likewise found no association between basal key parameters (innate and adaptive) of the immune system and body odor quality. Our results indicate that body odor may not serve as a cue to the reactivity of the immune system.

Smells Influence Perceived Pleasantness but Not Memorization of a Visual Virtual Environment.

The present study aimed to investigate whether the perception of still scenes in a virtual environment in congruent versus incongruent condition can be influenced by odors. Ninety healthy participants were divided into three groups, including two experimental virtual reality (VR) environments: a rose garden, an orange basket, and a control condition. In each VR condition, participants were exposed to a rose odor, an orange odor, or no odor, resulting in congruent, incongruent, and control conditions. Participants were asked to describe (a) the content of the VR scene and rate its overall pleasantness and (b) the smell and to rate its intensity and pleasantness. For each condition, participants were tested twice. During the second test, participants provided ratings and descriptions of the content of the VR scenes without being exposed to odors or VR environments. Virtual scenarios tended to be remembered as more pleasant when presented with congruent odors. Furthermore, participants used more descriptors in congruent scenarios than in incongruent scenarios. Eventually, rose odor appeared to be remembered as more pleasant when presented within congruent scenarios. These findings show that olfactory stimuli in congruent versus incongruent conditions can possibly modulate the perception of the pleasantness of visual scenes but not the memorization.

TOM-32-An extended test for the assessment of olfactory memory.

BACKGROUND: Olfactory memory testing is a promising way to explore different aspects of smell-related abilities in healthy subjects as well as to diagnose various diseases associated with disorders of this type of memory. Despite the obvious value of olfactory memory assessments, few available methods enable its diagnosis. NEW METHOD: The aim of our study was to create a standardized research tool designed for olfactory memory studies: an extended, 32-item version of an available "Test for Odor Memory". RESULTS: The study involving 222 subjects revealed satisfactory psychometric qualities of TOM-32, and - as hypothesized - subjects with depression scored significantly lower than healthy participants. We additionally showed that TOM-32 scores was associated with sex, age and olfactory awareness. Women performed significantly better than men, young people tended to have lower false alarm rate than older subjects and olfactory awareness was positively associated with olfactory memory. COMPARISON WITH EXISTING METHOD(S): TOM-32 could expand the possibilities of testing olfactory memory. It may offer additional information about cognitive and sensory abilities relative to existing research tools, and the large number of included test items may facilitate repeated and longitudinal testing. Wide range of applied odors increases the possibility to detect subtle differences between, as well as changes within, individuals. CONCLUSIONS: We present an extensive olfactory memory test with satisfactory psychometric qualities - a test that is comprehensive enough to show significant inter- and intra-individual differences, but time-efficient enough to be comfortable in daily research and clinical usage.

Body Odor Trait Disgust Sensitivity Predicts Perception of Sweat Biosamples.

Body odors are potent triggers of disgust and regulate social behaviors in many species. The role of olfaction in disgust-associated behaviors has received scant attention in the research literature, in part because olfactory disgust assessments have required laboratory testing with odors. We have devised the "Body Odor Disgust Scale" (BODS) to facilitate research on olfactory disgust. In this study, we evaluated whether individual differences in BODS scores would be associated with the perception of disgust for sweat samples in a laboratory setting. Results show that BODS was a strong predictor of disgust ratings of sweat samples even when controlling for general disgust sensitivity. In contrast, odor intensity ratings were unrelated to BODS scores. Our findings suggest that the BODS scores reflect body odor disgust perception. The BODS scale might facilitate research on olfactory disgust responses and associated behaviors.

Developmental Study on Leg-to-Body Ratio Preferences.

Few studies have tested developmental differences in the perception of human body attractiveness and none have investigated development of Leg-to-Body Ratio (LBR) preferences. The aim of the current study was to determine whether preferences for LBR are largely innate and present among children in their early childhood, acquired in the course of socialization, and/or triggered by biological and hormonal changes. The study included 450 Polish men and women from Lower Silesia and Opole Province, Poland, whose ages ranged from 3 to 20 years. Participants were asked to choose which figurine they found the most attractive from a set of male and female figurines of various LBRs. We found that children below 8 years of age did not prefer any particular LBR and starting from about 9 years of age, preferences towards the legs of average length emerged. Importantly an LBR higher than the population average was not perceived as the most attractive until the age of 15 years. Therefore, we have empirically confirmed that LBR preferences change during develop ment.