Null cross-modal effects of olfactory training on visual, auditory or olfactory working memory in 6- to 9-year-old children.

Systematic exposure to odours (olfactory training, OT) is a method of smell loss treatment. Due to olfactory system projections to prefrontal brain areas, OT has been hypothesized to enhance cognitive functions, but its effects have been studied predominantly in adults. This study tested OT effects on working memory (WM), i.e., the ability to store and manipulate information for a short time, in healthy children aged 6-9 years. We expected OT to improve olfactory WM and establish cross-modal transfer to visual and auditory WM. Participants performed 12 weeks of bi-daily OT with either 4 odours (lemon, eucalyptus, rose, cloves; OT group) or odourless propylene glycol (placebo group). Pre- and post-training, participants' WM was measured utilizing odours (olfactory WM) or pictures (visual WM) and a word-span task (auditory WM). 84 children (40 girls) completed the study. The analyses revealed no changes in the WM performance following OT. The olfactory WM task was the most difficult for children, highlighting the need to include olfactory-related tasks in educational programmes to improve children's odour knowledge and memory, just as they learn about sounds and pictures. Further neuroimaging research is needed to fully understand the impact of OT on cognitive functions in children.

Olfactory training in 8-year-olds increases odour identification ability: a preliminary study.

Olfactory training (OT), smelling odours, twice per day for an extended period, can improve the olfactory function in adults. The aim of the current study was to investigate whether OT can improve the olfactory function of children aged 8 years old. Odour thresholds and odour identification ability were compared between two groups across three separate testing sessions (baseline, 6-week post-baseline, 12-week post-baseline). After the baseline test, the control group (n = 21) completed 6 weeks of bi-daily OT with odourless stimuli, whereas the experiment group (n = 20) completed 6 weeks of bi-daily OT, smelling four different odours (eucalyptus, lemon, clove, rose). A repeated measure analysis of variance was used to test for group differences across the three testing sessions. Six weeks after OT had been completed, participants in the experiment group demonstrated a significant increase in odour identification scores (9.95 to 11.20), compared to the control group who demonstrated no increase (10.48 to 10.48). No group differences in odour threshold ability were found.Conclusion: Six weeks of OT enhances odour identification ability, but not odour thresholds, in 8-year-old children. What is Known: • Smell loss and dysfunction are associated with negative health outcomes such as depression and increased risk of consuming contaminated food. • Olfactory training can improve sense of smell in adults. What is New: • Olfactory training improves odour identification ability in 8-year-olds. • Olfactory training does not appear to enhance odour acuity in 8-year-olds.

Individual differences in the interoceptive states of hunger, fullness and thirst.

Interoception is the ability to perceive internal bodily states. This involves the detection and awareness of static and changing afferent signals from the viscera, motivational states, affective reactions, and associated cognitions. We examined whether there are individual differences in any or all of these aspects of ingestion-related interoception and their possible causes. Individual variation in almost all aspects of interoception was documented for hunger, fullness and thirst - including how participants use, prioritise and integrate visceral, motivational, affective and cognitive information. Individual differences may arise from multiple causes, including genetic influences, developmental changes hypothesised to result from child feeding practices, and from conditions such as depression, anxiety, eating disorders and certain subtypes of obesity. A nutritionally poor diet, and dietary restraint, may also affect ingestion-related interoception. Finally, certain forms of brain injury, notably to the medial temporal lobes are associated with impaired ingestion-related interoception. We conclude by examining the practical and theoretical consequences of these individual differences.

Evidence that phenomenal olfactory content exceeds what can later be accessed.

Visual experience is information rich, but only a small proportion is available for later access. We tested for this distinction in olfaction. In two experiments (E1&2), participants undertook trials rating an odor's features (e.g., how banana-like?), the during-smelling-profile, followed by an after-smelling-profile, upon the odor's removal. On some trials during and after-smelling-profiles were identical and on others they were different. Each trial with a particular odor was repeated. For half the odors both trials were identical (congruent) and for the remainder, one was different and the other identical (incongruent). Crucially, the after-smelling-profile was always the same for each odor, allowing reliability to be measured. E1&2 revealed that incongruent profiles were the least reliable. Attempting to access particular odor features in an odor's absence is harder if those features were not attended during smelling. This suggests more information is available during smelling, than can be accessed after the odors removal.

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

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 [...].

A Nationwide survey of safety protocols and chemosensory assessments by Japanese clinicians pre- and post-COVID-19 pandemic.

OBJECTIVE: There has been an increase of attention and awareness of smell and taste loss due to the impact of COVID-19. However, little is known about the influence of COVID-19 on the number of psychophysical tests performed, the timing of these tests, or the protection protocols employed to protect against virus transmission. This study aimed to explore the changes in examination approaches, types of tests employed, and safety measures adopted by clinicians before and after the COVID-19 pandemic. METHODS: A survey was distributed to 404 institutes of the Oto-Rhino Laryngological Society of Japan, consisting of otolaryngologists working in university hospitals, general hospitals, and private clinics. The anonymous online survey contained questions related to safety measures and chemosensory assessments performed before and after the COVID-19 pandemic. Specifically, participants were queried on the number and types of examinations conducted, the type of examiners who performed them, the timing of tests in suspected and non-suspected COVID-19 cases, modifications made due to the pandemic, and the protective measures adopted during chemosensory examinations. RESULTS: Of the 201 respondents, representing a 50 % response rate, 49 % were from general hospitals, 48 % from university hospitals, and 3 % from private clinics. The study found a slight decrease in the overall number of chemosensory tests conducted post-COVID-19. In terms of who performed the test, there were no differences pre- and post- COVID-19. Most examinations (52-68 %) for suspected COVID-19 cases were performed 1-2 months after the onset of symptoms. Modifications in testing rooms and personal protective equipment (PPE) were reported by the majority of institutions post-pandemic. While different examination rooms or PPE were not commonly used based on a patient's previous COVID-19 diagnosis, changes were observed in testing practices. Most examinations were conducted in rooms with windows or fans, and PPE usage was high; surgical masks, eye visors or face shields, and disposable gloves being commonly used. Virus transmission from patient to examiner was reported in only one case during T&T olfactometer examination. CONCLUSION: We investigated the impact of the COVID-19 pandemic on the number of olfactory and gustatory tests performed, the type of examiner, the examination room, and the use of PPE and found no significant difference before and after the COVID-19 pandemic on these factors. Adherence to a protection protocol involving the proper use of PPE in controlled environments enabled the continuation of olfactory and gustatory tests during the pandemic.

Using response consistency to probe olfactory knowledge.

Although we know much about familiar faces or objects that we temporarily cannot name, what do we know about familiar odors that we cannot name? Two experiments here examined this issue, by comparing the reliability of responses to various questions using 2 tests, with odors that were consistently named or given similar or very different names on each test occasion. Reliability estimates for various types of questions were then compared against each other and with a random baseline control, which reflected response consistency among the different odors on each test occasion. Experiment 1 probed response consistency for the core olfactory attributes-familiarity, edibility, and intensity-and for the components of the semantic differential (liking, activity, and potency). Experiment 2 probed response consistency for these latter items, as well as conceptual questions relating to the odors' source (e.g., solid or liquid?) and its similarity to other odors (e.g., how fruity?). In both experiments, when an odor was named very differently on each test occasion, the only response to remain consistent was "liking." We suggest that liking reflects the most basic form of information conveyed by the olfactory system.

Detecting olfactory rivalry.

Olfactory rivalry can occur when a binary mixture is sniffed repeatedly, with one percept dominating then the other. Experiment 1 demonstrated olfactory rivalry using several new techniques. Experiments 2 and 3 examined whether participants can notice rivalry. Participants received trials composed of odor pairs: either a mixture followed by the same mixture; or a pure odor followed by the same pure odor. On some trials participants judged whether the two stimuli were the same or different, to see if they could detect rivalry. On other trials participants judged the quality of each odor, allowing us to determine whether rivalry occurred. We found evidence for rivalry when we compared reports of odor quality for one stimulus and then the other, but no evidence that participants could detect this change. These findings are consistent with the idea that people can experience olfactory illusions, but may not know they have occurred.

Investigating the Link between Eating Attitudes, Taste and Odour Preferences and the Chemical Senses.

OBJECTIVES: To examine if higher degrees of pathological eating attitudes in a non-clinical sample are associated with odour and taste perception and preferences based on psychophysical ratings. PARTICIPANTS AND METHODS: A total of 80 female university students completed the eating attitudes test (EAT-26), followed by four chemosensory measures including olfactory and gustatory perception plus perceptual ratings and preferences for food odours and tastes. RESULTS: There were no significant correlations between EAT-26 scores and measures of olfactory and gustatory perception. However, a significant interaction effect indicated higher degrees of pathological eating attitudes may be associated with differential sensitivity to sweet and fatty food odours compared to those with lower levels of pathological eating attitudes. CONCLUSIONS: This was the first study to examine pathological eating attitudes using food stimuli with a non-clinical sample. The results remain preliminary until replication. However, the findings highlight the need for development of measures of disordered eating attitudes and behaviours that go beyond caloric restriction.

Do you often sniff yourself or others? Development of the Body Odor Sniffing Questionnaire and a cross-cultural survey in China and the USA.

OBJECTIVES: Body odor can convey much information about an individual and thus we frequently engage in sniffing one's own and other people's body odor. However, there is scarce evidence on the within- and cross-cultural variation in body odor sniffing behaviors and no psychometric scale for specifically measuring such behaviors. Hence, our study aimed to develop the Body Odor Sniffing Questionnaire (BOSQ) and used it to make a cross-cultural comparison. METHODS: In Study 1, 2,026 participants were recruited from our university, with one half used for exploratory factor analysis (EFA) to examine the factor structure of the BOSQ (sample 1) and the other half used for confirmatory factor analysis (CFA) to verify the factor structure (sample 2). In Study 2, 352 Chinese and 254 US participants were recruited to complete the BOSQ through Wenjuanxing and Amazon Mechanical Turk, enabling comparison of body odor sniffing behaviors across two cultures. RESULTS: The Study 1 results showed that the BOSQ comprises 17 items in three factors: self-private body odor, others' body odor, and self-common body odor. The CFA results further supported that this three-factor model was a good fit. The Study 2 results showed that US participants scored higher overall and on the self-private body odor and others' body odor dimensions, whereas Chinese participants scored higher on the self-common body odor dimension. CONCLUSIONS: The BOSQ demonstrated good reliability and validity, which is a useful tool for evaluating individuals' body odor sniffing behaviors. Cross-cultural difference existed as the US population reported a higher prevalence of body odor sniffing behavior, compared to the Chinese population.

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

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.

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

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.

A New Method for Assessment of Retronasal Olfactory Function.

OBJECTIVES/HYPOTHESIS: The aim of the study was to develop a test for the assessment of retronasal olfaction in healthy participants and patients with olfactory disorders using "tasteless" powders. STUDY DESIGN: Prospective case-control series. METHODS: A total of 150 participants (110 women, 40 men, mean age = 40 ± 16 years) were recruited for this study; 100 were healthy controls and 50 were patients with olfactory loss due to infections of the upper respiratory tract (n = 25), idiopathic causes (n = 12), sinonasal disease (n = 7), and head trauma (n = 6). Orthonasal olfactory function was evaluated using the Sniffin' Sticks test battery, and retronasal olfaction was evaluated using powders lacking distinctive tastes administered to the oral cavity. To establish test-retest reliability, healthy participants had their orthonasal and retronasal function tested twice. RESULTS: The validity analyses revealed that the selected 16 stimuli differentiated between normosmic participants and patients with olfactory loss, and that retronasal and orthonasal olfaction were highly correlated. CONCLUSIONS: The results of the present study indicate that patients with olfactory loss and controls can be clearly separated using a reliable test of retronasal olfaction based on 16 retronasal stimuli. LEVEL OF EVIDENCE: 2b Laryngoscope, 131:E324-E330, 2021.

The Aetiology of Olfactory Dysfunction and Its Relationship to Diet Quality.

People with olfactory loss may choose foods rich in sugar, salt and fat to compensate their loss-foods that constitute a Western-style diet (WSD). However, olfactory dysfunction has not been consistently linked to any particular type of dietary change. Here we considered whether the aetiology of olfactory dysfunction may affect consumption of a WSD. Two-hundred and twenty-two people with olfactory dysfunction of varying cause, were tested for chemosensory performance and their frequency of consumption of a WSD. There was no evidence of a link between a WSD and olfactory dysfunction at the aggregate level, but an aetiology-based approach revealed various patterns, showing both positive and negative associations between olfactory performance and consumption of a WSD. We suggest a number of reasons why, in certain cases, greater olfactory dysfunction may be linked to lower intakes of a WSD, and the role that different aetiologies may have in affecting choices for foods that may appeal following olfactory impairment.

Global study of variability in olfactory sensitivity.

Variability in human olfactory sensitivity has been attributed to individual-level factors such as genetics, age, sex, medical history of infections and trauma, neurogenerative diseases, and emotional disorders. Scarce evidence exists on the cross-cultural variation in olfactory sensitivity. Hence, we performed 2 studies to estimate the variability in olfactory threshold as a function of location and environment. Study 1 involved 11 laboratories from 4 continents (N = 802). In each location, in a designated laboratory, approximately 80 subjects underwent olfactory sensitivity testing with custom-made tests with eucalyptol and phenylethanol (PEA) odors. Tests were based on the Threshold subtest of the Sniffin' Sticks battery. In Study 2, we compared olfactory sensitivity and suprathreshold perception of PEA and eucalyptol in 2 Chinese (N = 160) and 2 Indian (N = 92) populations-one based in their native country and the other in Germany. Both studies present large-scale evidence that olfactory sensitivity varies as a function of geographical location and suggest that environmental factors play an important role in shaping olfactory sensitivity and suprathreshold olfactory perception. We delineate further steps necessary to identify specific factors underlying uncovered variability and the relationship between olfactory sensitivity and suprathreshold odor perception. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

The role of body odors and olfactory ability in the initiation, maintenance and breakdown of romantic relationships - A review.

The aim of this review is to present direct and indirect lines of converging evidence that highlight the many ways our body odors and sense of smell may influence the three broad stages of romantic relationships; initiation, maintenance and breakdown. This emerging area of study requires a multidisciplinary empirical approach. Here we survey research findings that taken together, suggest that body odor perception moderates mate choice, provides a source of comfort in existing relationships and may signal the breakdown of a relationship through disgust processes. In terms of olfactory ability, having a good sense of smell may facilitate identifying a healthy mate, enhance sexual experiences, relationship security and ensure empathic responsivity, predictors of relationship longevity. We therefore conclude that olfaction plays an important - yet understudied - role in romantic relationships.

Do Single Men Smell and Look Different to Partnered Men?

Previous research indicates human body odor (BO) can signal kinship, sickness and genetic compatibility. Based on research indicating single males have higher testosterone levels than partnered males and that higher testosterone levels are associated with stronger smelling BO, the current study aimed to determine if, by extension of previous findings, single males' BO smells stronger than partnered males' BO. Eighty-two heterosexual women aged 18-35 years rated the BO and faces of six different males also aged 18-35 years. Consistent with the hypothesis, single men's BO smelled stronger than partnered men's BO and single men's faces were rated as more masculine than partnered men's faces. The possible advantages of females being able to identify single males are addressed in the Discussion.

Do women love their partner's smell? Exploring women's preferences for and identification of male partner and non-partner body odor.

Despite evidence indicating body odor (BO) preference is an important driver in mate selection, previous studies have only investigated females' preferences for the BO of strangers. Therefore, the aim of the current study was to determine if partnered females prefer their partner's BO compared to that of others males' BO. Forty partnered and 42 single, heterosexual women aged 18-35 years, brought to the laboratory a shirt their partner or male friend/relative (respectively) sweated in while wearing. The results indicated that both partnered and single women (blindly) rated their known donor's BO as smelling significantly more similar, familiar and sexy compared to six unknown male's BO, but rated their known donor's BO as less intense smelling than unknown males' BO. While participants indicated they liked their known donor's BO more than that of unknown males' BO, the difference was not statistically significant. Moreover, participants were unlikely to rank their known donor's BO as their most preferred of seven BOs. Finally, partnered and single participants could reliably recognise their known donor's BO and that of unknown males' which was driven by their ability to indicate a stranger's BO was not that of known donor's. Overall, these preliminary findings suggest that partnered females may prefer their partners' BO but this preference may not be due to mate selection but instead a consequence of repeated exposure to their partner's BO.

Age-related changes in odor discrimination.

Odor naming and recognition memory are poorer in children than in adults. This study explored whether such differences might result from poorer discriminative ability. Experiment 1 used an oddity test of discrimination with familiar odors on 6-year-olds, 11-year-olds, and adults. Six-year-olds were significantly poorer at discrimination relative to 11-year-olds and adults, who did not differ. Experiment 2 used the same procedure but with hard-to-name visual stimuli and compared only 6-year-olds with adults (as with the remaining experiments in this study). There was no difference in performance between these groups. Experiment 3 used the same procedure as Experiment 1 but with less familiar odors. Six-year-olds were significantly poorer at discrimination than adults. In Experiment 4 the researchers controlled for verbal labeling by using an articulatory suppression task, with the same basic procedure as in Experiment 1. Six-year-old performance was the same as for Experiment 1 and significantly poorer than that of adults. Impoverished olfactory discrimination may underpin performance deficits previously observed in children. These all may result from their lesser experience with odors, relative to adults.

Usefulness of the Threatening Medical Situations Inventory in individuals considering genetic testing for cancer risk.

OBJECTIVE: To assess the psychometric properties of the Threatening Medical Situations Inventory (TMSI) in a community sample (Study 1), and to examine its usefulness in individuals with a strong family history of cancer (Study 2). METHODS: Study 1 participants (N=276) completed 2 online surveys, 14 days apart. Study 2 participants (N=311) completed 2 questionnaires, 6 months apart. RESULTS: Both studies revealed the inventory was psychometrically sound, although some concerns were raised about the factor structure. High monitors in Study 1 reported desiring more health-related information and an active role in medical decision-making. High monitors in Study 2 had the greatest knowledge increase when they received a detailed decision aid, compared to a brief pamphlet. CONCLUSION: The TMSI is appropriate for use in both community and clinical samples. High monitors in the general community are more likely to prefer receiving as much health-related information as possible and desire an active role in decision-making about their health. PRACTICE IMPLICATIONS: Familial cancer clinic patients may benefit from tailoring the amount of information they receive to their coping style, such that patients who are vigilant information-seekers may benefit most from receiving more detailed information about genetic testing.