Editorial

5 pages, 189 KiB

Open AccessEditorial

Investigating the Interplay between Olfaction, Social Behaviour, and Individual Differences: Editorial

by Laiquan Zou and Mehmet K. Mahmut

Brain Sci. 2024, 14(2), 142; https://doi.org/10.3390/brainsci14020142 - 30 Jan 2024

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Long-COVID mercilessly brought awareness to what olfaction researchers have known all along; losing your sense of smell changes your experiences with the world around you and can compromise your health and wellbeing [...] Full article

(This article belongs to the Special Issue Investigating the Interplay between Olfaction, Social Behaviour, and Individual Differences)

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14 pages, 1146 KiB

Open AccessArticle

A Fresh Look on Old Clothes: Laundry Smell Boosts Second-Hand Store Sales

by Jasper H. B. de Groot, Charly Walther and Rob W. Holland

Brain Sci. 2022, 12(11), 1526; https://doi.org/10.3390/brainsci12111526 - 10 Nov 2022

Cited by 1 | Viewed by 2009

Abstract

The clothing industry is one of the biggest polluters impacting the environment. Set in a sustainable environment, this study addresses whether certain ambient odors can influence the purchase of second-hand clothing. This study fulfilled three aims, increasing methodological, statistical, and theoretical rigor. First, [...] Read more.

The clothing industry is one of the biggest polluters impacting the environment. Set in a sustainable environment, this study addresses whether certain ambient odors can influence the purchase of second-hand clothing. This study fulfilled three aims, increasing methodological, statistical, and theoretical rigor. First, replicating the finding that fresh laundry odor can boost purchasing behavior in a second-hand store—this time in a larger sample, using a fully counterbalanced design, in a pre-registered study. Second, assessing the effectiveness of another cleanliness priming control condition (citrus odor) unrelated to the products at hand, to test hypotheses from a hedonic vs. utilitarian model. Third, combining questionnaire data tapping into psychological processes with registered sales. The results (316 questionnaires, 6781 registered transactions) showed that fresh laundry odor significantly increased the amount of money spent by customers compared to the no smell condition, (replication) and compared to citrus odor (extension). Arguably, fresh laundry odor boosts the utilitarian value of the product at (second) hand by making it smell like non-used clothing, ultimately causing customers to purchase far greater amounts in this sustainable setting. Full article

(This article belongs to the Special Issue Investigating the Interplay between Olfaction, Social Behaviour, and Individual Differences)

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17 pages, 909 KiB

Open AccessArticle

Is That “Mr.” or “Ms.” Lemon? An Investigation of Grammatical and Semantic Gender on the Perception of Household Odorants

by Theresa L. White, Caitlin M. Cunningham and Mary L. Zampini

Brain Sci. 2022, 12(10), 1313; https://doi.org/10.3390/brainsci12101313 - 28 Sep 2022

Viewed by 1199

Abstract

Linguistic relativism is the idea that the structure of language influences thought. The present study investigates linguistic relativism by asking whether people who speak a gendered language think of objects in a way that is consistent with the grammatical gender (more masculine or [...] Read more.

Linguistic relativism is the idea that the structure of language influences thought. The present study investigates linguistic relativism by asking whether people who speak a gendered language think of objects in a way that is consistent with the grammatical gender (more masculine or feminine) more than people who speak a language without that linguistic feature. Odorants are unique stimuli for examining this question, because they carry a semantic gender without a biological one, yet gender is thought to be a central dimension of their perception. Canadian participants in the present study (native French or native English speakers) described a set of labeled odorants that varied systematically in grammatical and semantic gender to produce an implicit gender measure and also explicitly rated them for gender. Analysis of the implicit femininity contained in participants’ descriptions showed a tendency for both native French and native English speakers to produce descriptions that were consistent with semantic gender; moreover, there were no effects of grammatical gender on implicit or explicit ratings. These results suggest that in a bilingual culture, French speakers may have been influenced by the anthropomorphism associated with odorants rather than grammatical gender. Full article

(This article belongs to the Special Issue Investigating the Interplay between Olfaction, Social Behaviour, and Individual Differences)

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15 pages, 1219 KiB

Open AccessArticle

Correlations between Persistent Olfactory and Semantic Memory Disorders after SARS-CoV-2 Infection

by Julie Fiorentino, Magali Payne, Elisa Cancian, Alexandra Plonka, Louise-Émilie Dumas, David Chirio, Élisa Demonchy, Karine Risso, Florence Askenazy-Gittard, Nicolas Guevara, Laurent Castillo, Philippe Robert, Valeria Manera, Clair Vandersteen and Auriane Gros

Brain Sci. 2022, 12(6), 714; https://doi.org/10.3390/brainsci12060714 - 31 May 2022

Cited by 7 | Viewed by 2817

Abstract

Background: One of the main symptoms of COVID-19 is hyposmia or even anosmia. Olfactory identification is most often affected. In addition, some cognitive disorders tend to appear following the infection, particularly regarding executive functions, attention, and memory. Olfaction, and especially olfactory identification, [...] Read more.

Background: One of the main symptoms of COVID-19 is hyposmia or even anosmia. Olfactory identification is most often affected. In addition, some cognitive disorders tend to appear following the infection, particularly regarding executive functions, attention, and memory. Olfaction, and especially olfactory identification, is related to semantic memory which manages general knowledge about the world. The main objective of this study was to determine whether semantic memory is impaired in case of persistent post COVID-19 olfactory disorders. Methods: 84 patients (average age of 42.8 ± 13.6 years) with post COVID-19 olfactory loss were included after consulting to the ENT department. The clinical evaluation was carried out with the Pyramid and Palm Tree Test, the word-retrieval task from the Grémots, the Sniffin’ Sticks Test and the Computerised Olfactory Test for the Diagnosis of Alzheimer’s Disease. Results: Semantic memory was impaired in 20% (n = 17) of patients, especially in the 19–39 age-group. The olfactory threshold was only significantly correlated with the semantic memory scores. Conclusions: Similar to all cognitive disorders, semantic disorders can have a negative impact on quality of life if left untreated. It is essential to carry out specific assessments of post COVID-19 patients to accurately determine their disorders and to put in place the best possible rehabilitation, such as speech and language therapy, to avoid quality-of-life impairment. Full article

(This article belongs to the Special Issue Investigating the Interplay between Olfaction, Social Behaviour, and Individual Differences)

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11 pages, 1707 KiB

Open AccessArticle

The Effect of Odor Valence on Facial Attractiveness Judgment: A Preliminary Experiment

by Guo Feng and Jiawei Lei

Brain Sci. 2022, 12(5), 665; https://doi.org/10.3390/brainsci12050665 - 19 May 2022

Cited by 3 | Viewed by 2280

Abstract

The role of social odors on human social interactions, including face evaluation, has been widely indicated. However, for nonsocial odors, there has not been a consistent conclusion. Therefore, this study aimed to verify the effect of suprathreshold nonsocial odors on facial attractiveness judgment [...] Read more.

The role of social odors on human social interactions, including face evaluation, has been widely indicated. However, for nonsocial odors, there has not been a consistent conclusion. Therefore, this study aimed to verify the effect of suprathreshold nonsocial odors on facial attractiveness judgment when the visual input is ambiguous. We designed a 3 (odor valence: neutral, pleasant, and unpleasant) × 7 (continuous levels of morphed fuzziness of attractiveness: 37.5% to 62.5%) within-subject experiment. A total of 30 participants (18 females) completed the whole experiment simultaneously for three consecutive days. The results showed that faces presented with pleasant and neutral odors were judged as significantly more attractive than those with unpleasant odors. The intervention effect of odor valence on facial attractiveness differed by fuzzy attractiveness levels. Results also suggested that male faces were perceived as more attractive than female faces no matter the odor conditions. The results of this study provide evidence to support the cross-modal emotion integration effect of olfaction and vision. Follow-up studies need to be conducted to reveal the underlying mechanism of odor valence on visual fact attractive judgment. Full article

(This article belongs to the Special Issue Investigating the Interplay between Olfaction, Social Behaviour, and Individual Differences)

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9 pages, 432 KiB

Open AccessArticle

Reading the Mind through the Nose: Mentalizing Skills Predict Olfactory Performance

by Katrin T. Lübke, Tobias C. Blum and Bettina M. Pause

Brain Sci. 2022, 12(5), 644; https://doi.org/10.3390/brainsci12050644 - 13 May 2022

Cited by 2 | Viewed by 2581

Abstract

A growing body of literature suggests a close link between olfaction and social expertise. The current study examines whether mentalizing skills are related to olfactory discrimination performance. In order to assess their mentalizing ability, 21 women and 20 men completed the “Reading the [...] Read more.

A growing body of literature suggests a close link between olfaction and social expertise. The current study examines whether mentalizing skills are related to olfactory discrimination performance. In order to assess their mentalizing ability, 21 women and 20 men completed the “Reading the Mind in the Eyes” test (RMET). Here, the participants have to infer other persons’ mental state from photographs of eye regions. Odor discrimination was assessed using the “Düsseldorf Odour Discrimination Test” (DODT). The DODT consists of 15 items, each containing mixtures of four monomolecular substances. Within each item, two bottles contain the same mixing ratio, while the third contains the reversed mixing ratio. The participants had to identify the deviating odor. Women’s expertise in mentalizing (RMET score) is strongly related to olfactory discrimination performance (DODT score): The better women are in mentalizing, the better their performance in olfactory discrimination (rho = 0.572, p = 0.042, Bonferroni-corrected). Men’s mentalizing capability was unrelated to olfactory discrimination (rho = −0.117, p > 0.999, Bonferroni-corrected). The current results suggest that the social skill of mentalizing might underly the link between olfaction and social integration, at least in women, and are discussed with regard to the social nature of human olfaction. Full article

(This article belongs to the Special Issue Investigating the Interplay between Olfaction, Social Behaviour, and Individual Differences)

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9 pages, 841 KiB

Open AccessArticle

Odor Identification Ability as a Mediator of Schizotypal Traits and Odor Hedonic Capacity in Non-Clinical Children and Adolescents

by Ying Chen, Yuyang Zhan, Yiqi Qiu, Jiubo Zhao and Laiquan Zou

Brain Sci. 2022, 12(5), 534; https://doi.org/10.3390/brainsci12050534 - 22 Apr 2022

Cited by 1 | Viewed by 1407

Abstract

Background: Previous studies have investigated the relationship between schizotypal traits and odor identification ability as well as the relationship between schizotypal traits and odor hedonic capacity in adults. However, very little is known about the relationship among these three factors, especially in children [...] Read more.

Background: Previous studies have investigated the relationship between schizotypal traits and odor identification ability as well as the relationship between schizotypal traits and odor hedonic capacity in adults. However, very little is known about the relationship among these three factors, especially in children and adolescents. The current study aimed to explore the relationship among these three factors in children and adolescents as well as the potential role of odor identification ability. Method: A total of 355 non-clinical children and adolescents (aged 9–16 years) were recruited in the study. They were asked to complete the Universal Sniff Test (U-Sniff), the Chemosensory Pleasure Scale for Children (CPS-C), and the Schizotypal Personality Questionnaire—Child (SPQ-C). Results: The SPQ-C scores were negatively correlated with both the odor identification scores and the odor hedonic scores (p = 0.022 and p < 0.001, respectively). Only the interpersonal–affective factor of the SPQ-C was negatively correlated with the odor identification scores (p = 0.031). The odor identification scores were significantly positively associated with the odor hedonic scores (p < 0.001). Moreover, the relationship between odor hedonic capacity and schizotypal traits, especially the interpersonal–affective factor, was mediated by odor identification ability. Conclusions: Schizotypal traits were negatively correlated with both odor identification ability and odor hedonic capacity in children and adolescents, while odor identification ability was found to mediate the relationship between odor hedonic capacity and schizotypal traits, especially the interpersonal–affective factor. Our study indicated that improving odor identification ability through olfactory training may have a positive influence on odor hedonic capacity in individuals with schizotypal traits. Full article

(This article belongs to the Special Issue Investigating the Interplay between Olfaction, Social Behaviour, and Individual Differences)

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12 pages, 1277 KiB

Open AccessArticle

Differences in Odor Identification in Early-Onset and Late-Onset Depression

by Meiling Liu, Ben Chen, Xiaomei Zhong, Min Zhang, Qiang Wang, Huarong Zhou, Zhangying Wu, Le Hou, Qi Peng, Si Zhang, Minfeng Yang, Gaohong Lin and Yuping Ning

Brain Sci. 2022, 12(2), 276; https://doi.org/10.3390/brainsci12020276 - 16 Feb 2022

Cited by 4 | Viewed by 2270

Abstract

(1) Background: Odor identification (OI) dysfunction is a potential predictor of developing dementia in late life depression (LLD). However, it is not clear whether patients with early onset depression (EOD) and late onset depression (LOD) may exhibit different OI dysfunctions. The aim of [...] Read more.

(1) Background: Odor identification (OI) dysfunction is a potential predictor of developing dementia in late life depression (LLD). However, it is not clear whether patients with early onset depression (EOD) and late onset depression (LOD) may exhibit different OI dysfunctions. The aim of this study was to compare OI between EOD patients and LOD patients and its relationship with cognitive function. (2) Methods: A total of 179 patients with LLD and 189 normal controls were recruited. Participants underwent clinical assessment, olfactory testing, and comprehensive neuropsychological assessment. The OI scores of EOD patients and LOD patients were compared, and correlation analyses and mediation analyses were used to explore the relationship between OI and cognition. (3) Result: LOD patients exhibited lower OI scores than EOD patients and normal controls (NCs). Additionally, the LOD patients exhibited a higher percentage of OI dysfunction than the EOD patients. Moreover, OI scores were associated with global cognition, memory, language, and visuospatial ability in the EOD group (p < 0.05) but were not associated with any cognitive score in the LOD patients (p > 0.05). Finally, the scores of the Auditory Verbal Learning Test Immediate recall and Boston Naming Test exhibited a partially mediating effect on the difference in OI scores between the EOD and LOD patients. (4) Conclusions: LOD patients exhibited worse OI than EOD patients, and their difference in OI was mediated by their memory and language function. Full article

(This article belongs to the Special Issue Investigating the Interplay between Olfaction, Social Behaviour, and Individual Differences)

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12 pages, 1989 KiB

Open AccessEditor’s ChoiceArticle

The Shape of the Olfactory Bulb Predicts Olfactory Function

by Xiaoguang Yan, Akshita Joshi, Yunpeng Zang, Francisca Assunção, Henrique M. Fernandes and Thomas Hummel

Brain Sci. 2022, 12(2), 128; https://doi.org/10.3390/brainsci12020128 - 18 Jan 2022

Cited by 7 | Viewed by 2318

Abstract

The olfactory bulb (OB) plays a key role in the processing of olfactory information. A large body of research has shown that OB volumes correlate with olfactory function, which provides diagnostic and prognostic information in olfactory dysfunction. Still, the potential value of the [...] Read more.

The olfactory bulb (OB) plays a key role in the processing of olfactory information. A large body of research has shown that OB volumes correlate with olfactory function, which provides diagnostic and prognostic information in olfactory dysfunction. Still, the potential value of the OB shape remains unclear. Based on our clinical experience we hypothesized that the shape of the OB predicts olfactory function, and that it is linked to olfactory loss, age, and gender. The aim of this study was to produce a classification of OB shape in the human brain, scalable to clinical and research applications. Results from patients with the five most frequent causes of olfactory dysfunction (n = 192) as well as age/gender-matched healthy controls (n = 77) were included. Olfactory function was examined in great detail using the extended “Sniffin’ Sticks” test. A high-resolution structural T2-weighted MRI scan was obtained for all. The planimetric contours (surface in mm²) of OB were delineated manually, and then all surfaces were added and multiplied to obtain the OB volume in mm³. OB shapes were outlined manually and characterized on a selected slice through the posterior coronal plane tangential to the eyeballs. We looked at OB shapes in terms of convexity and defined two patterns/seven categories based on OB contours: convex (olive, circle, and plano-convex) and non-convex (banana, irregular, plane, and scattered). Categorization of OB shapes is possible with a substantial inter-rater agreement (Cohen’s Kappa = 0.73). Our results suggested that non-convex OB patterns were significantly more often observed in patients than in controls. OB shapes were correlated with olfactory function in the whole group, independent of age, gender, and OB volume. OB shapes seemed to change with age in healthy subjects. Importantly, the results indicated that OB shapes were associated with certain causes of olfactory disorders, i.e., an irregular OB shape was significantly more often observed in post-traumatic olfactory loss. Our study provides evidence that the shape of the OB can be used as a biomarker for olfactory dysfunction. Full article

(This article belongs to the Special Issue Investigating the Interplay between Olfaction, Social Behaviour, and Individual Differences)

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14 pages, 285 KiB

Open AccessArticle

Love Stinks: The Association between Body Odors and Romantic Relationship Commitment

by Madeleine Keaveny and Mehmet Kibris Mahmut

Brain Sci. 2021, 11(11), 1522; https://doi.org/10.3390/brainsci11111522 - 17 Nov 2021

Viewed by 2684

Abstract

Anecdotal reports indicate that women dislike their partner’s body odor (BO) during the breakdown of a relationship; however, whether disliking a partner’s BO is associated with intentions to break up has not been empirically tested. Therefore, the aim of the current study was [...] Read more.

Anecdotal reports indicate that women dislike their partner’s body odor (BO) during the breakdown of a relationship; however, whether disliking a partner’s BO is associated with intentions to break up has not been empirically tested. Therefore, the aim of the current study was to investigate, for the first time, whether disliking one’s partner’s BOs is associated with experiencing lower commitment to a romantic relationship. Eighty participants (48 partnered, 32 single and previously partnered) completed self-report questionnaires about their current or previous romantic relationship and the amount of exposure to—and hedonic ratings of—their current or former partner’s BOs. Olfactory function was also tested, and participants smelled and rated various pieces of clothing imbued with a stranger’s BO. The results demonstrated that for participants who had experienced a breakup, historically higher levels of relationship commitment were associated with higher hedonic ratings of a previous partner’s BOs, regardless of the type of BOs. For participants currently in a relationship, lower relationship commitment was associated with higher breakup intentions in response to smelling their partner’s BOs. These preliminary results contribute evidence for the positive association between exposure to a partner’s BOs and favorable hedonic appraisals of BOs; however, further research needs to be conducted in this area to investigate nuances. Lower levels of exposure to one’s partner’s BOs may be more indicative of relationship commitment than exposure to hedonically unpleasant BOs of one’s partner. The findings are discussed with reference to their implications for interventions in relationship breakdown. Full article

(This article belongs to the Special Issue Investigating the Interplay between Olfaction, Social Behaviour, and Individual Differences)

12 pages, 659 KiB

Open AccessArticle

The Link between Attachment Style and Self-Reported Olfactory Ability: A Preliminary Investigation

by Amy Shell, Anna Blomkvist and Mehmet K. Mahmut

Brain Sci. 2021, 11(10), 1367; https://doi.org/10.3390/brainsci11101367 - 18 Oct 2021

Cited by 3 | Viewed by 2081

Abstract

Individuals in healthy romantic relationships gain significant benefits to their psychological wellbeing and physiological health. Notably, the majority of relationship research has focused on how adult attachment influences these relationship outcomes while the role of olfaction remains an emerging research focus. The aim [...] Read more.

Individuals in healthy romantic relationships gain significant benefits to their psychological wellbeing and physiological health. Notably, the majority of relationship research has focused on how adult attachment influences these relationship outcomes while the role of olfaction remains an emerging research focus. The aim of the current study was to bring together these seemingly unrelated factors–attachment and olfaction–in an online quasi-experimental design. The participants were 401 undergraduate students, predominantly females, ranging in age from 17 to 70 years. Participants completed a battery of questionnaires that evaluated their attachment tendencies, olfactory ability and experiences in romantic relationships. Results indicated that attachment insecurity, across both attachment anxiety and avoidance, was associated with decreased olfactory functioning for females. These findings provide preliminary evidence that olfaction is related to romantic relationship maintenance and suggests that body odors could be fundamental for evoking the attachment system. These findings also elicit enticing new avenues of research which can assist psychologists to provide targeted treatments to individuals with olfactory deficits and insecure attachment tendencies. Full article

(This article belongs to the Special Issue Investigating the Interplay between Olfaction, Social Behaviour, and Individual Differences)

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