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Mother-child bonding is associated with body odor perception
Abstract
Mothers can recognize the odor of their baby and typically like this odor very much. In line with this observation, infant body odors activate reward-related brain areas in the mothers. In some mother-child-dyads however, the mutual bond is impaired and mothers have trouble engaging in interaction with their child. We aimed to examine how mothers with bonding difficulties perceive their child's body odor. In total 75 mothers and their babies (aged 0-12 months) were examined: Twenty-five of those were recruited in a psychosomatic day hospital ward, which is specialized for mother-child bonding disorders. Fifty age-matched healthy women and their babies served as controls. Body odor samples of each baby were collected from bodysuits in a highly standardized procedure. Thereafter, each mother rated the samples of her own and of two stranger's infants in a blindfolded and randomized design. In addition, general olfactory function in terms of threshold and identification ability was tested and the mother reported the bonding to her baby in a standardized questionnaire. Healthy mothers showed a clear preference of the own compared to odors of strange infant's, while mothers with bonding difficulties did not. Furthermore, the degree of preference was negatively correlated to self-reported bonding difficulties. Mothers with bonding difficulties could not identify their own infant's odor above chance, while control mothers could (p = 0.02). Both groups did not differ in general olfactory function. We assume that reduced close body contact and interaction time in bonding difficulties may lead to reduced olfactory stimulation and hinder the recognition of the infantile body odor. Within a vicious cycle, a reduced hedonic experience smelling the own baby may prevent women from deliberately approaching the baby. Thus the positive and bond-building consequences of bodily and sensory interaction cannot unfold. As the baby's odor is normally perceived as very pleasant and rewarding, the conscious perception of the infantile body odor may be an additive therapeutic approach for mothers with bonding difficulties.
... It is observed that on the fourth and fifth day after birth, the mother's ability to distinguish decreases and improves again on the eighth day. This decreased ability to identify odours is associated with increased maternal depression scores on those days [13,14]. Mothers and/or other adults may be aware of the scents emitted by babies and may actively seek out the scent of such odours in everyday interactions. ...
... It has also been reported that human body odours are used as chemical cues for genetic recognition [4]. The extremely positive connotation of infantile body odour is especially evident for children under 1 year old [13]. In a study conducted by Schäfer et al. [14] showed that mothers identified and preferred their own child's body odour. ...
... This first physical contact is also the starting point for the reception of childhood chemical signals and olfactory communication [63]. Interpersonal communication is probably mostly shaped by the perception of body odours unconsciously [13]. In mammals, olfactory cues emitted by newborn infants and/or mothers are essential for the establishment of mother-infant interaction during birth. ...
Introduction
The sense of smell is one of the most developed and important senses that forms the bond between the newborn and the mother and allows the newborn to reach the mother's breast. The sense of smell begins to form during intrauterine life, and the sense of smell can be a marking tool for a newborn baby, so that the baby can recognize both his mother and his immediate environment and develop his behaviour accordingly. This is necessary not only for feeding babies but also for them to feel safe and peaceful in their new environment. In the early stages of life, olfactory stimulation (maternal odour, breast milk odour, amniotic fluid odour, smell of people or different environments) plays an important role in adapting to the environment. Smell stimulation, in particular, is critical for newborns' postnatal survival because it supports a wide range of early regulatory functions and motor responses. This review also aims to examine the current evidence in the field of olfactory skills in mother and infant in the development and care of the infant. Another aim is to summarize the research conducted to determine the effect of the sense of smell on the life of the mother and baby.
Methods
The article was written as a comprehensive review using certain keywords.
Results
However, the results on this issue are different. First of all, it is suggested that in the first years of life, the sense of smell can play an important role in social adaptation to the environment, recognition of the environment, mother–infant bonding, and therefore in this case, it is recommended to make olfactory stimulating interventions.
Conclusion
However, more well‐designed experimental studies are needed in this regard. We look forward to future studies that closely examine various aspects of how olfactory stimulation affects both mother and baby.
... Previous investigations of body odour perception in parent-child dyads have mainly focused on mothers and showed that mothers are able to identify their own infant's odour and prefer it over the body odour of unfamiliar infants [11][12][13], Mothers with postpartum bonding disorders however do not exhibit olfactory kin recognition and do not prefer the own infant's odour [11]. ...
... Previous investigations of body odour perception in parent-child dyads have mainly focused on mothers and showed that mothers are able to identify their own infant's odour and prefer it over the body odour of unfamiliar infants [11][12][13], Mothers with postpartum bonding disorders however do not exhibit olfactory kin recognition and do not prefer the own infant's odour [11]. ...
... The link between hedonic impression and recognition of the "own" offspring, supports the idea that selective attachment is facilitated by affective universal biological signals, such as the Kindchenschema [7] or, in this case, the pleasant odour of a child. This positive affective perception seems relevant for initial attachment between mother and baby and is reduced in mothers with postpartum bonding difficulties [11]. Perceived pleasantness of one's own baby's odour has further been associated with positive feelings [60]. ...
... Among other purposes, this serves as insurance of the survival of the offspring because in this way rearing resources can be invested in a targeted manner [36] and the formation of an affectionate bond is facilitated [42]. In previous literature, it was shown that olfactory kin recognition is a reliable phenomenon in healthy individuals: Mothers are able to identify their children above chance level [8,25,43]. Therefore, a reliable kin recognition performance may indicate the quality of BO sampling. The authors of Kaitz [25] found a link between the capability of kin recognition and the length of exposure to their infant's BO. ...
... However, this statement differed from the experimental results. In view of other experimental studies on children's BOs, it is not surprising that the infantile axillary odour was perceived as very pleasant [8,43]. Hence, the findings presented here might point to differences between questionnaire and experimental studies. ...
... We are aware of the limitations of the data presented here based on the small sample size. The resulting insufficient sensitivity of the sample could, e.g., have contributed to the lack of findings regarding a maternal preference for the BO of the own infant: While we investigated 28 mothers and observed only a tendency towards higher pleasantness ratings for one's own child's BO compared to unfamiliar BOs, prior studies reporting a strong preference effect included N = 50 mothers [43] and N = 167 mothers [8]. ...
Body odours and their importance for human chemical communication, e.g., in the mother–child relationship, are an increasing focus of recent research. Precise examination of sampling methods considering physiology and feasibility aspects in order to obtain robust and informative odour samples is therefore necessary. Studies comparing body odour sampling at different body sites are still pending. Therefore, we sampled axilla, breast, and head odour from 28 mother–infant dyads and examined whether odour perception differs with regard to the body site. The participating mothers were asked to evaluate their own and their infant’s body odour samples, as well as odours of two unfamiliar mother–infant dyads. We tested whether maternal pleasantness and intensity evaluation, as well as recognition ability of the odours differed between the body sites. In infants, the head odour exhibited slightly lower pleasantness ratings than axilla and breast, and intensity ratings did not differ between body sites. In mothers, body site affected intensity ratings but not pleasantness ratings, as the breast odour was rated as less intense compared with head and axilla. Across all body sites, mothers rated the own and their infant’s odour as less intense when compared with unfamiliar samples. Recognition ability did not differ between body sites, and in line with previous studies, mothers were able to recognize their own and their own infant’s odour above chance. In sum, our study extends the previous methodological repertoire of body odour sampling and indicates that the axilla, breast, and head of adults as well as infants serve as informative odour sources.
... Another group of studies revealed increased preference of odours from close kin and BO identification abilities within families [9,10]. BO preference is mediated by identification ability; in contrast to healthy mothers who are able to identify their own child's odour shortly after birth [10], mothers with impaired bonding to their child can neither identify nor prefer their own child's BO [11]. Whereas the maternal ability is preserved irrespective of whether the child is infantile, pubertal or post-pubertal, there are inconsistencies in paternal olfactory kin recognition across these developmental stages [10,12,13]. ...
... Using Bayesian statistics [47,48], we additionally explored the likelihood of the first parts of H1 (identification of the own child above chance) and H2 ( preference of the own over other children), as for these hypotheses basic assumptions about the effect sizes of preference and identification of one's own child are available based on a previous publication [11]. For further information, see electronic supplementary material (Bayesian analyses). ...
... Further research into olfactory-mediated parental affection could investigate carers with either an impaired sense of smell or an impaired relationship to their child. Although we know that mothers with impaired bonding to their child do not prefer or recognize their child's odour [11], it is unclear whether royalsocietypublishing.org/journal/rstb Phil. Trans. ...
Mothers are able to identify the body odour (BO) of their own child and prefer this smell above other BOs. It has hence been assumed that the infantile BO functions as a chemosignal promoting targeted parental care. We tested this hypothesis and examined whether children's BOs signal genetic similarity and developmental status to mothers. In addition, we assessed whether BOs facilitate inbreeding avoidance (Westermarck effect). In a cross-sectional design, N = 164 mothers participated with their biological children ( N = 226 children, aged 0–18 years) and evaluated BO probes of their own and four other, sex-matched children. Those varied in age and in genetic similarity, which was assessed by human leucocyte antigen profiling. The study showed not only that mothers identified and preferred their own child's BO, but also that genetic similarity and developmental status are transcribed in BOs. Accordingly, maternal preference of their own child's odour changes throughout development. Our data partly supported the Westermarck effect: mothers' preference of pubertal boys' BOs was negatively related to testosterone for the own son, but not for unfamiliar children.
This article is part of the Theo Murphy meeting issue ‘Olfactory communication in humans’.
... In addition, we carried out a sensory evaluation study with young adults, using an artificial mixture of 14 major components of volatile substances emitted by the neonate head within an hour of birth, 13 components from the head of babies 2 or 3 days postpartum, and 10 components from amniotic fluid obtained at the time of birth. Considering the psychological and/or physiological effects of the odor of amniotic fluid and neonates, which are probably among the earliest cues to promote mother-infant communication 10,18,19,29,38,39 , the combination of chemical analysis combined with sensory evaluation reported here is a potentially important contribution to research on early mother-infant bonding and communication. ...
... Even newborn babies try to avoid unpleasant treatments, and this renders it difficult to collect odors from neonates under stress-free conditions. It is for these reasons that few observations are available on the odors of newborn babies, and those that have been done have typically made use of the clothes used by babies instead of collecting the odors directly [36][37][38][39] . ...
... Not only kin recognition but also early mother-infant bonding and communication may be mediated by odors emitted from infants [25][26][27]38 . As humans are social species, infants might rely on attracting the attention of their mother, father, other relatives or other adults in situations where their survival is endangered. ...
For baby odor analyses, noninvasive, stress-free sample collection is important. Using a simple method, we succeeded in obtaining fresh odors from the head of five newborn babies. These odors were chemically analyzed by two-dimensional gas chromatography coupled with mass spectrometry (GC × GC-MS), and compared with each other or with the odor of amniotic fluid from the baby’s mother. We identified 31 chemical components of the volatile odors from neonate heads and 21 from amniotic fluid. Although 15 of these components were common to both sources, there was an apparent difference in the GC × GC patterns between the head and amniotic fluid odors, so the neonate head odor might be individually distinct immediately after birth. Therefore, we made artificial mixtures of the major odor components of the neonate head and maternal amniotic fluid, and used psychological tests to examine whether or not these odors could be distinguished from each other. Our data show that the artificial odor of a neonate head could be distinguished from that of amniotic fluid, and that the odors of artificial head odor mixtures could be correctly discriminated for neonates within an hour after birth and at 2 or 3 days of age.
... For example, mothers who are not able to recognize their own child's body odor do not show a preference for their child's odor. Consistent with this, Croy et al. (2019) showed that mothers with postpartum bonding disorders had a lower preference for their own child's body odor, compared to healthy controls. Further, in a recent study conducted in our lab, we presented 164 healthy mothers to body odor probes of their own and sex-matched unfamiliar children in different age groups, from infancy to adulthood (Schäfer et al., in press). ...
... As our study points out, perceptual assessment was a strong predictor for age classification across all mothers. Pleasantness was related to prepubertal classification, which is in line with previous findings on positive evaluation of infant's body odor (Fleming et al., 1993;Okamoto et al., 2016;Croy et al., 2017Croy et al., , 2019. Moreover, pleasantness perception of an infant's odor is an important cue mediating parental care as it facilitates affectionate love (Okamoto et al., 2016). ...
Mothers can recognize their own children by body odor. Besides signaling familiarity, children’s body odors may provide other information relevant to maternal caregiving behavior, such as the child’s developmental status. Thus, we explored whether mothers are able to classify body odors on pre- vs. postpubertal status above chance levels. In total, 164 mothers were presented with body odor samples of their own and four unfamiliar, sex-matched children who varied in age (range 0–18 years). Pubertal status was measured by (a) determining the child’s steroid hormone level and (b) parental assessment of the child’s developmental stage using the Pubertal Development Scale. Mothers classified developmental status with an accuracy of about 64%. Maternal assessments were biased toward pre-puberty. Classification was predicted by perceptual evaluation of the body odor (i.e. intensity and pleasantness) and by the child’s developmental stage, but not by hormones. In specific, mothers with pubertal-aged children classified body odors using the child’s developmental status, whereas mothers with younger children only classified body odors using perceptual information (i.e. intensity and pleasantness). Our data suggests that body odors convey developmental cues, but how this developmental information is manifested in body odor remains unclear.
... (2019) mengenai hubungan keterikatan ibu dan bayi dengan persepsi ibu terhadap aroma badan bayi yang melaporkan bahwa ibu yang sehat menunjukkan sikap mampu mengenali aroma badan bayinya. 21 Temuan ini sejalan dengan studi oleh Schafer et al. (2020) mengenai pengaruh aroma badan bayi terhadap keterikatan ibu dan bayi yang menyimpulkan bahwa ibu yang menyukai aroma tubuh bayinya cenderung memiliki kedekatan dengan bayinya, dan meningkatkan keterikatan emosional ibu dan bayi. 22 Bayi baru lahir memiliki bioritme yang seringkali ditampilkan dalam perilaku menangis yang tidak teratur. ...
Keterikatan ibu dan bayi pasca persalinan membantu ibu menstimulasi perkembangan fisiologis dan psikologis bayi. Di sisi lain, prosedur Enhanced Recovery After Cesarean Section (ERACS) meningkatkan keterikatan ibu dan bayi. Tujuan penelitian ini adalah untuk mengeksplorasi pengalaman keterikatan ibu dan bayi pasca ERACS. Penelitian ini merupakan penelitian kualitatif. Pengambilan data dilakukan dengan wawancara semi terstruktur kepada tujuh responden 12 jam setelah ERACS. Analisis data penelitian ini menggunakan analisis tematik. Hasil penelitian didapatkan lima tema utama yang teridentifikasi, meliputi inisiatif ibu mencari sumber informasi mengenai keterikatan ibu dan bayi, respons positif ibu terhadap kelahiran bayinya, perilaku promosi ibu dalam meningkatkan keterikatan dengan bayinya, dukungan perawatan bayi dan ibu pasca persalinan dan intensitas keterikatan yang terbangun. Kesimpulan dari penelitian ini ERACS mengoptimalkan keterikatan ibu dan bayi melalui dukungan perilaku promosi keterikatan ibu dengan bayi melalui praktik kontak kulit ke kulit segera setelah persalinan serta pemulihan dini memungkinkan ibu mendapat dukungan suami untuk meningkatkan keterikatan dengan bayinya.
... FMc, which is present in multiple areas of the female brain [3], was found in approximately 80% of glioblastoma cases and 50% of meningioma cases [4]. Preliminary reports suggest that FMc could be a protective factor against Alzheimer's disease [3], but a promoter of Parkinson's disease in a murine model [5]. FMc may play a role in the mother's mental health [6], although this hypothesis remains untested. ...
The persistence of fetal cells in the mother (fetal microchimerism (FMc)) has been described in maternal tissues essential to the newborn. FMc is associated with several diseases that start or worsen in pregnancy or postpartum. This exploratory study reports—for the first time—the presence of FMc in the olfactory neuroepithelium (ON) of both healthy and depressed women with male offspring. However, depressed women had fewer microchimeric cells (digital PCR). The existence of FMc in the ON could facilitate mother–child bonding. These findings open new pathways to study FMc in the ON, female depression, and mother–child bonding.
... Hiermit wird folglich die Eltern-Kind Bindung gestärkt. Interessanterweise sind Mütter mit diagnostizierten Bindungsproblemen zum Kind schlechter in der Lage, den Geruch ihrer Kinder zu erkennen und -im Gegensatz zu Müttern mit guter Bindung-bevorzugen sie den Geruch ihrer Kinder auch nicht [29]. ...
Zusammenfassung
Für viele Spezies ist der Geruchssinn das bedeutsamste Sinnessystem, um mit der Umwelt und Artgenossen zu interagieren. Demgegenüber wurde die Rolle der Wahrnehmung und Kommunikation chemosensorischer Informationen beim Menschen lange Zeit unterschätzt. Der menschliche Geruchssinn galt als weniger zuverlässig, sodass diesem im Vergleich mit visuellen und auditiven Sinneseindrücken weniger Bedeutung beigemessen wurde. Seit einiger Zeit befasst sich ein wachsender Forschungszweig mit der häufig nur unterbewusst wahrgenommenen Rolle des Geruchssinnes für Emotion und soziale Kommunikation. Dieser Zusammenhang soll im Folgenden genauer betrachtet werden. Zur besseren Verständlichkeit und Einordnung werden zunächst die wesentlichen Hintergründe zu Aufbau und Funktion unseres Riechsystems thematisiert. Darauf aufbauend wird auf die Bedeutung eingegangen, die das Riechen für zwischenmenschliche Kommunikation und unsere Emotionalität hat. Daraus lässt sich schlussfolgern, dass Personen mit Riechstörungen spezifische Lebensqualitätseinschränkungen erleben.
... All odorous molecules, whether natural or synthetic and whether perceived as pleasant or unpleasant, are highly volatile and can activate the olfactory receptors present in the human nose or in the olfactory organs of all animals [8][9][10][11][12][13][14]. In particular, in humans the perception of odors has been observed to affect the quality of life, exerting a relevant influence on eating habits of individuals and consequently on their body weight, on the ability to perceive molecules that signal the presence of dangers (e.g., toxic and/or harmful gases, smoke and spoiled food) and in interpersonal relationships [15][16][17][18][19][20]. ...
The flavor of foods and beverages is generally composed of a mixture of volatile compounds, however not all the molecules that form an aroma are sensorially relevant. The odor-active compounds present in a mixture are different for each subject, both in quantitative and qualitative terms. This means that the ability of the human nose to act as a chemical sensor varies among individuals. In this study, we used the headspace of roasted coffee beans as a complex olfactory stimulus and, by means of the coupled Gas Chromatography-Olfactometry (GC-O) technique, the single components of coffee flavor were separated. Each subject, previously classified for his/her olfactory status (normosmic, hyposmic or anosmic) by means of the Sniffin’ Sticks battery (composed of Threshold, Discrimination and Identification subtests), had to identify and evaluate each smelled molecule. The results show that the individual ability to detect individual compounds during the GC-O experiments and the odor intensity reported during the sniffing of pen #10 (the pen of the identification test) containing coffee aroma were related to TDI olfactory status (based on the score obtained from the sum composed of Threshold, Discrimination and Identification scores). We also found that the number of total molecules and of molecules smelling of coffee is linearly related to the TDI olfactory score. Finally, the odor intensity reported when sniffing pen #10 containing coffee aroma is positively correlated with the number of molecules detected and the average intensity reported. In conclusion, our findings show that the human perception of both individual compounds and complex odors is strongly conditioned by the olfactory function of subjects.
... First, romantic partner odor: social odors play an important role in mate selection by affecting desirability [10,[26][27][28] with this process being only partially subconscious, as both men and women seem aware of using odors in their mate choice [29]. Second, odors of familiars or significant others: these social odors provide a feeling of security and familiarity and help the relationship maintenance [30][31][32][33][34]. Familiar social odors include odors from significant others, family members, and friends [16, 18,[35][36][37]. Third, stranger's body odors: these odors are processed as a dangerous and threatening stimulus and they are rated as more unpleasant and ...
The degree of attention individuals pay to olfactory cues (called odor awareness) influences the role of odors in everyday life. Particularly, odors produced by the human body (i.e., social odors) are able to carry a wide variety of information and to elicit a broad spectrum of emotional reactions, making them essential in interpersonal relationships. Hence, despite the assessment of awareness toward social odors is crucial, a proper tool is still lacking. Here, we designed and initially validated the Social Odor Scale (SOS), a 12-item scale designed to measure the individual differences in awareness towards different social odors. In Study 1, an exploratory factor analysis (EFA; KMO test: MSA = 0.78; Bartlett’s test: χ²(78) = 631.34, p < 0.001; Chi-squared test: χ²(42) = 71.84, p = 0.003) suggests that the three factors structure was the model that best fit with the Italian version of the scale. The confirmatory factor analysis (CFA) supports a second-order model with one higher-order factor representing social odor awareness in general and three lower-order factors representing familiar, romantic partner, and stranger social odors. The final version of the scale presented a good fit (RMSEA = 0.012, SRMR = 0.069, CFI = 0.998, TLI = 0.997). In Study 2, CFA was performed in the German version of the scale confirming the validity of scale structure. Study 3 and 4 revealed that SOS total score and its subscales were positively correlated with other validated olfactory scales, but not with olfactory abilities. Moreover, SOS was found to be related to the gender of the participants: women reported to be more aware to social odors and, specifically, to familiar social odors than men. Overall, the results indicated that SOS is a valid and reliable instrument to assess awareness toward social odors in everyday life.
... In general identities are produced through bonding and delimitation. On the one hand, body odors contribute already to mother-infant bonding (Croy et al. 2019), and the smellscapes of childhood in uence feelings of attachment to certain environments. On the other hand, social and racial discrimination, marginalization and exclusion have for a long time invoked offensive odors of others' bodies and places; in spite of their elusiveness and transience, odors divided as sharply as a knife populations and supported oppressive apparatuses. ...
Contemporary smelly artworks, installations and “scent sculptures” endorse philosophical and anthropological theories about the construction of identity as a relation to oneself and the others through consciousness and memory (John Locke), as a multi-staged process of social exchange (George H. Mead), as a game of risk and trust in making one’s own identity (Anthony Giddens), and as a dialectics of agency and passivity (Gernot Böhme). It is well-known that topophilic emplacement contributes to identity; olfactory site-specific installations and practices “present” specific smellscapes and reflect on their changes. Also olfactory artists who produce uncanny atmospheres recall that personal identity is built along the axes of trust and anxiety. Body odors in general are corporeal signatures that enable individual recognition, yet artists extract them in order to challenge taboos, question gender stereotypes and build open identities. The crucial role of odors for both self-acceptance and non-verbal communication makes artists use them as a means of fostering a new sense of solidarity on a local as well as on a global level. Finally, other artistic projects subvert the anthropological difference and rehabilitate other species’ olfactory sensitivity. With the aid of modern technology, they promise to fulfil old dreams about enlarging the spectrum of our nose and controlling incoming odors and body emissions. Thus, in a paradoxical way, they both advocate to return to the prehuman and urge to become posthuman.
... A single review was identified which studied olfactory sensitivity in pregnancy, and the authors noted that more research is needed to support anecdotal data and the relationship to hormonal changes of pregnancy [34]. Olfaction has been associated with maternal-infant bonding [35], which is a process that may be interrupted or delayed in preterm births. This area of research may benefit from the inclusion of epigenetics to examine potential long-term effects on cellular functioning in mothers. ...
Background
Preterm birth (< 37 weeks’ gestation) is a common outcome of pregnancy that has been associated with increased risk of cardiovascular disease for women later in life. Little is known about the physiologic mechanisms underlying this risk. To date, no studies have evaluated if differences in DNA methylation (DNAm) among women who experience preterm birth are short-term or if they persist and are associated with subsequent cardiovascular sequelae or other health disorders. The purpose of this study was to examine long-term epigenetic effects of preterm birth in African American mothers ( n = 182) from the InterGEN Study (2014–2019). In this study, we determine if differences in DNAm exist between women who reported a preterm birth in the last 3–5 years compared to those who had full-term births by using two different approaches: epigenome-wide association study (EWAS) and genome-wide co-methylation analyses.
Results
Though no significant CpG sites were identified using the EWAS approach, we did identify significant modules of co-methylation associated with preterm birth. Co-methylation analyses showed correlations with preterm birth in gene ontology and KEGG pathways. Functional annotation analysis revealed enrichment for pathways related to central nervous system and sensory perception. No association was observed between DNAm age and preterm birth, though larger samples are needed to confirm this further.
Conclusions
We identified differentially methylated gene networks associated with preterm birth in African American women 3–5 years after birth, including pathways related to neurogenesis and sensory processing. More research is needed to understand better these associations and replicate them in an independent cohort. Further study should be done in this area to elucidate mechanisms linking preterm birth and later epigenomic changes that may contribute to the development of health disorders and maternal mood and well-being.
... People emit odors that reflect personal characteristics from the axillary areas, breath, eyes (through tears), and hands [16]. These odors are unique to an individual [15,19] and can be used to infer that person's identity [14,20]; for example, a mother can recognize her child by its scent, e.g., [21]. Some enduring physical traits, such as biological sex, are reflected in a person's body odor [22]; smells arising from both the breath [23] and the underarms [24][25][26] can be correctly categorized as originating from a man or a woman, though this is not consistently observed [27]. ...
First impressions of social traits are regularly, rapidly, and readily determined from limited information about another individual. Relatively little is known about the way that olfactory information, particularly from scents that are not body odors, alters a first impression. Can the attributes of an odorant be conferred onto a person associated with that scent? To explore this, 101 participants were asked to form an impression of a hypothetical person based on the following stimuli: A gender-neutral silhouette, a list of six personal characteristics, and one of five odorants. Participants then rated the likelihood that the hypothetical person possessed each of 51 personality traits that were determined a priori as falling into six attribute categories. Participants also directly rated all odorants for the six categories and intensity. A T-test showed that ratings of the hypothetical person were less disparate from the odor that was presented during impression formation than from other odors. ANOVA revealed that the effects were heterogeneous, with odorants varying in their effectiveness in associating the hypothetical person with categories. The present data suggest that a hypothetical person can be imbued with the specific attributes of an odor and that some odors are better at contributing to impressions than others.
... In this case, smelling a body odor proxy would enhance social needs, consequently driving social cohesion. This mechanism would be consistent with the assumed bonding role of body odors in mother-child interactions throughout the early stages of a human life (Croy et al., 2019;Porter et al., 1983;Schäfer et al., 2020). However, quite an opposite mechanism may also be true. ...
Olfactory deficits can play a detrimental role in everyday social functioning. Perception of 3-hydroxy-3-methylhexanoic acid (HMHA)—a body odor component—could also be linked to this research area. However, no study so far has addressed the problem of HMHA perception in the context of the previously reported relationship between olfactory abilities and social difficulties. Here, we tested whether HMHA-specific anosmia predicted loneliness understood both as a cognitive evaluation of social participation and as one’s social isolation, and we additionally analyzed the effects and correlates of HMHA perception in relation to sightedness. The study comprised 196 people, of whom 99 were blind. We found that subjects with blindness declared particularly high loneliness, but HMHA anosmia and the interaction of sightedness and HMHA anosmia predicted neither loneliness nor social withdrawal. In addition, HMHA pleasantness was positively associated with social withdrawal of the subjects with blindness and emotional loneliness correlated with HMHA familiarity regardless of sightedness.
... The sense of smell plays a critical role in various aspects of human life, and its important functions can be grouped into three broad categories: avoidance of environmental hazards, social communication and ingestive behavior [2]. Olfaction draws attention to warning signs, such as predators, fire, smoke, toxic substances or poisons and spoiled food [3,4]; it impacts reproductive behavior [5][6][7][8][9]; it affects interpersonal communication, such as between a mother and her baby [10]; it contributes to the localization, choice and intake of food, and it modulates appetite [2,[11][12][13][14][15][16][17][18][19]. ...
Smell strongly contributes to food choice and intake, influencing energy balance and body weight; its reduction or loss has been related to malnutrition problems. Some patients with inflammatory bowel disease (IBD), mainly Crohn’s disease (CD) and ulcerative colitis (UC), are underweight, while others are overweight. Some studies suggest that changes in eating habits could be linked to specific disorders of the olfactory functions. We assessed the olfactory performance in 199 subjects (healthy control (HC) n = 99, IBD n = 100), based on the olfactory Threshold, Discrimination and Identification score (TDI score), measured with the “Sniffin’ Sticks” test. Subjects were genotyped for the rs2590498 polymorphism of the OBPIIa gene. IBD patients showed both a slightly, but significantly, lower olfactory function and a higher BMI compared to HC subjects. Threshold (in both population) and Discrimination (in IBD patients) olfactory score were affected by the OBPIIa genotype. BMI was influenced by both health status and OBPIIa genotype. A lower olfactory function may delay the satiety sensation and thus increase meal duration and body weight in IBD patients. However, the AA genotype of the OBPIIa seems to “protect” IBD patients from more severe olfactory dysfunction.
... First, romantic partner odor: social odors play an important role in mate selection by affecting desirability [10,[26][27][28] with this process being only partially subconscious, as both men and women seem aware of using odors in their mate choice [29]. Second, odors of familiars or significant others: these social odors provide a feeling of security and familiarity and help the relationship maintenance [30][31][32][33][34]. Familiar social odors include odors from significant others, family members, and friends [16, 18,[35][36][37]. Third, stranger's body odors: these odors are processed as a dangerous and threatening stimulus and they are rated as more unpleasant and ...
The degree of attention individuals pay to olfactory cues (called odor awareness) influence the role of odors in everyday life. Particularly, odors produced by the human body (i.e., social odors) are able to carry a wide variety of information and to elicit a broad spectrum of emotional reactions, making them essential in interpersonal relationships. Hence, despite the assessment of awareness toward social odors is crucial, a proper tool is still lacking. Here, we designed and validated the Social Odor Scale (SOS), a measure to assess the individual differences in awareness towards different social odors. In Study 1, an exploratory factor analysis (EFA) supports the initially developed four factor structure of the Italian version of the scale. In Study 2, EFA was performed in the German version of the scale confirming the validity of scale structure. Finally, a confirmatory factor analysis (Study 4) corroborates the construct validity of the SOS and its subscales. Hence, the final version of SOS is composed of 16 items, four for each subscale: own, familiar, romantic partner, and stranger social odors. Study 3 and 4 revealed that SOS total score and its subscales were positively correlated with other validated olfactory scales, but not with olfactory abilities. Moreover, SOS was found to reflect the inter-individual variability that characterize social odor processing: SOS was related to age, gender and reproductive state of the participants. Overall, the results indicated that SOS is a valid and reliable instrument to assess awareness toward social odors in everyday life.
... Whilst heterozygous STS deletion has no apparent effect on gross olfactory function (Cavenagh et al. 2019), a more subtle effect cannot be discounted, particularly given that STS inhibition is associated with taste disturbance in female subjects (Stanway et al. 2006). As the olfactory system and limbic regions extensively connected to it are known to play an important role in mammalian maternal behaviour (Corona and Lévy 2015;Croy et al. 2019), it is plausible that STS deficiency acts to elicit postpartum behavioural symptoms in humans and mice via disturbed olfactory receptor function; potentially, disturbed olfaction could adversely impact upon intermediate phenotypes such as mother-offspring bonding, social judgement, sensory anhedonia, and/or stress modulation. Feasibly, abnormal olfactory processing and the abnormal activity of underlying neural and molecular substrates may play a role in idiopathic postpartum mood disorder risk; consistent with this idea, aberrant olfactory function has been described in several non-postpartum mood conditions (Kamath et al. 2018). ...
Postpartum mood disorders develop shortly after childbirth in a significant proportion of women. These conditions are associated with a range of symptoms including abnormally high or low mood, irritability, cognitive disorganisation, disrupted sleep, hallucinations/delusions, and occasionally suicidal or infanticidal ideation; if not treated promptly, they can substantially impact upon the mother's health, mother-infant bonding, and family dynamics. The biological precipitants of such disorders remain unclear, although large changes in maternal immune and hormonal physiology following childbirth are likely to play a role. Pharmacological therapies for postpartum mood disorders can be effective, but may be associated with side effects, concerns relating to breastfeeding, and teratogenicity risks when used prophylactically. Furthermore, most of the drugs that are used to treat postpartum mood disorders are the same ones that are used to treat mood episodes during non-postpartum periods. A better understanding of the biological factors predisposing to postpartum mood disorders would allow for rational drug development, and the identification of predictive biomarkers to ensure that 'at risk' mothers receive earlier and more effective clinical management. We describe new findings relating to the role of the enzyme steroid sulfatase in maternal postpartum behavioural processes, and discuss how these point to a novel molecular risk pathway underlying postpartum mood disorders. Specifically, we suggest that aberrant steroid hormone-dependent regulation of neuronal calcium influx via extracellular matrix proteins and membrane receptors involved in responding to the cell's microenvironment might be important. Testing of this hypothesis might identify novel therapeutic targets and predictive biomarkers.
... Smell and taste play a primary role in the survival of many species of invertebrates and vertebrates, including humans [1][2][3][4][5][6][7][8]. Olfactory and gustatory information allows animals to locate and choose food, identify predators, select a partner for mating, mother-infant recognition and to avoid potentially harmful situations [9][10][11][12][13][14][15][16][17]. ...
Olfactory function varies by several orders of magnitude among healthy individuals, who may exhibit a reduced sensitivity (hyposmia), a high sensitivity (hyperosmia), or an olfactory blindness (anosmia). Environmental and genetic factors seem to account for this variability. Most of odorant molecules are hydrophobic and it has been suggested that odorants are transported to the olfactory receptors by means of odorant binding proteins (OBPs). Aim of this study was to evaluate the presence of a relationship between the olfactory performance of healthy subjects and the polymorphism in the odor binding-protein (OBPIIa) gene, the only OBP found in the olfactory epithelium of humans. Using the "Sniffin' Sticks" Extended Test we assessed the olfactory performance in 69 subjects, who were genotyped for the rs2590498 polymorphism of the OBPIIa gene, whose major allele A has been associated with a higher retronasal perception as compared to the minor allele G. We found that subjects homozygous for the A-allele exhibited threshold scores higher than subjects homozous for the G-allele or heterozygous. In addition, subjects classified as normosmic and hyposmic differed on the basis of genotype distribution and allelic frequencies. In fact, a normosmic condition was associated with genotype AA and allele A and a hyposmic condition was associated with genotype GG and allele G. In conclusion, our results show that a relationship exists between the physiological variations of olfactory performance and the OBPIIa gene polymorphism.
... Olfaction has been described as "the neglected sense." 1 It serves many practical functions such as appreciating the taste of food, aiding communication between mother and child, and is an essential occupational tool for professional wine tasters, chefs, and perfumers. [2][3][4] Olfaction is important for detecting danger and is especially important to fire fighters, gas shop attendants and homemakers. 1,5 Unpleasant odours adversely affect social interactions, and people with olfactory impairments may become isolated for fear of them or their environment being smelly and this, going undetected by them. ...
p class="abstract"> Background: Olfactory function has been shown to be impaired in human immunodeficiency virus (HIV) infection. The advent of anti-retroviral therapy has resulted in prolonged survival of these patients requiring increased focus on factors that affect their quality of life including olfaction.
Methods: The study was conducted at the University of Benin Teaching Hospital, Benin City. Consenting adult HIV positive patients were assisted to fill a proforma after which they had rigid nasendoscopy done to rule out peripheral causes of anosmia such as nasal infections, nasal polyps and tumours. The brief smell identification test (BSIT) scratch and sniff tests were then administered to those included in the study. The same procedure was repeated with consenting HIV negative subjects serving as control.
Results: There was a statistically significant difference between olfactory identification ability of HIV positive and HIV negative adults (p=0.001). Cases were 2.92 times likely to have abnormal smell identification abilities than controls.
Conclusions: Olfactory identification ability is reduced in PLWHA relative to the HIV negative population.</p
During the long domestication process, humans and dogs built a strong bond. Attachment in the dog–human relationship is characterized by successful communication and cooperation involving olfactory signals. It is known that dogs are able to smell stress in humans. In this study, we investigate whether humans can also smell stress in dogs and whether dog owners are better at identifying the smell of stressed dogs than non‐dog owners. Odor samples of four dogs were taken during a relaxed and stressed situation. A total of 20 dog owners and 20 non‐dog owners participated in the experiment in which they smelled the odor samples while blindfolded. Our results show that the participants were unable to correctly discriminate the smell of relaxed dogs from that of stressed dogs. Furthermore, dog owners did not perform better than non‐dog owners.
The smell of the own baby is a salient cue for human kin recognition and bonding. We hypothesized that infant body odors function like other cues of the Kindchenschema by recruiting neural circuits of pleasure and reward. In two functional magnetic resonance imaging (fMRI) studies, we presented infantile and postpubertal body odors to nulliparae and mothers (N=78). All body odors increased BOLD response and functional connectivity in circuits related to olfactory perception, pleasure and reward. Neural activation strength in pleasure and reward areas positively correlated to perceptual ratings across all participants. Compared to postpubertals, infant body odors specifically enhanced BOLD signal and functional connectivity in reward and pleasure circuits, suggesting that infantile body odors prime the brain for prosocial interaction. This supports the idea that infant body odors are part of the Kindchenschema. The additional observation of functional connectivity being related to maternal and kin state speaks for experience-dependent priming.
Body odors change during development, and this change influences the interpersonal communication between parents and their children. The molecular basis for this chemical communication has not been elucidated yet. Here, we show by combining instrumental and sensory analyses that the qualitative odorant composition of body odor samples is similar in infants (0-3 years) and post-pubertal children (14-18 years). The post-pubertal samples are characterized by higher odor dilution factors for carboxylic acids and by the presence of 5α-androst-16-en-3-one and 5α-androst-16-en-3α-ol. In addition to the olfaction-guided approach, the compounds 6-methylhept-5-en-2-one (6MHO), geranyl acetone (GA) and squalene (SQ) were quantified. Both age groups have similar concentrations of 6MHO and GA, whereas post-pubertal children tend to have higher concentration of SQ. In conclusion, sexual maturation coincides with changes to body odor chemical composition. Whether those changes explain differences in parental olfactory perception needs to be determined in future studies with model odors.
Although chemical signaling is an essential mode of communication in most vertebrates, it has long been viewed as having negligible effects in humans. However, a growing body of evidence shows that the sense of smell affects human behavior in social contexts ranging from affiliation and parenting to disease avoidance and social threat. This article aims to (a) introduce research on human chemical communication in the historical context of the behavioral sciences; (b) provide a balanced overview of recent advances that describe individual differences in the emission of semiochemicals and the neural mechanisms underpinning their perception, that together demonstrate communicative function; and (c) propose directions for future research toward unraveling the molecular principles involved and understanding the variability in the generation, transmission, and reception of chemical signals in increasingly ecologically valid conditions. Achieving these goals will enable us to address some important societal challenges but are within reach only with the aid of genuinely interdisciplinary approaches.
Body odors serve as signals of kinship, with parents exhibiting a preference for the scent of their infants, and vice versa. The reciprocal perception of body odors can promote bonding through two mechanisms. Firstly, as an indirect pathway, through associative chemosensory learning, which leads to changes in proximity-seeking behaviors. Secondly, as a direct pathway, by eliciting the display of positive emotions, thereby reinforcing the mutual bond. Both mechanisms weaken as the child undergoes development due to changes in body odor expression and perception. This comprehensive review provides an overview of the current literature on chemosignals in the parent-child relationship, highlighting their significance in facilitating dyadic communication throughout the developmental span. Furthermore, future research perspectives are outlined to gain a better understanding of these benefits and, on the long run, derive potential interventions to strengthen parent child attachment.
Background:
Body odor is an important aspect in interpersonal communication. For psychological and chemical research on body odors, suitable procedures for sampling and application, and analysis of body odors are essential. In this study, different textile fabrics (polyester, cotton, and Gazin gauze) were comparatively evaluated in view of their potential suitability for body odor sampling by determining recovery rates of selected body odor substances. In addition, the impact of sample preparation and storage conditions on the recovery rates was determined.
Results:
The recovery rates of dimethyl disulfide, (E)-non-2-enal, 5α-androst-16-en-3-one, 6-methylhept-5-en-2-one, heptanal and 3-sulfanylhexan-1-ol were determined under different conditions of storage (storage for 30 min at room temperature or storage for 30 min at room temperature followed by freezing at - 80 °C for 4 weeks) and sample work-up (solvent extraction with and without solvent-assisted flavour evaporation, in the following: SAFE). SAFE led to overall lower recovery rates with a significant effect for (E)-non-2-enal and 5α-androst-16-en-3-one. Nevertheless, the results showed that SAFE can be an essential step when working with a complex matrix. When comparing the different fabrics, except for (E)-non-2-enal no difference between the recovery rates obtained for cotton and polyester became evident. Gazin gauze showed lower recovery rates for all compounds. Finally, our results showed that the here investigated target compounds are stable during storage for four weeks at - 80 °C.
Significance and novelty:
The results show on the one hand that the here investigated compounds were stable during storage and that the fiber type had limited influence on overall recovery rates. On the other hand, they highlight the limitations of using textile materials for sampling of volatile substances, especially with regard to low recovery rates for certain substances and the necessity of material pre-treatment or distillation steps for enabling GC-MS analysis after solvent extraction.
Olfactory impairment is one of the more unique symptoms of COVID-19 infection, and has therefore enjoyed increased public attention in recent months. Olfactory impairment has various implications and consequences ranging from difficulty detecting dangerous pathogens to hindering social functioning and social behaviours. We provide an overview of how olfactory impairment can impact three types of close social relationships; family relationships, friendships and romantic relationships. Evidence is divided into several categories representing potential mechanisms by which olfactory impairment can impact close social relationships: bonding disruptions, decreased social support, missed group-eating experiences, hygiene concerns, and altered sexual behaviours. We conclude with a discussion of emerging future research questions.
The sense of smell essentially contributes to social communication, guides nutrition behaviour and elicits avoidance towards environmental hazards. Olfactory smell impairment may hence entail severe consequences for affected individuals. Compared with sensory loss in other modalities, reduced olfactory function is often unnoticed by those affected and diagnosed late. Those patients seeking help frequently suffer from long-term impairments resulting in reduced well-being and quality of life. The current review provides an overview of aetiology, prevalence and specifics of diagnostics in acquired and congenital olfactory loss and focusses on short- and long-term consequences. Compensation strategies are elaborated, and treatment options are mentioned. Individual characteristics associated with the development of serious mental health impairment are discussed in order to help practitioners identifying populations at risk.
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.
Introduction
Infant body odor is subjectively pleasant to parents and activates reward areas in the brain. Hence, body odor perception might contribute to parental bonding. However, it is unknown whether the perceived pleasantness of children’s body odor varies over the course of a child’s development.
Methods
Two hundred and thirty-five parents (M = 36.9 years, SD = 7.3) were asked to assess the personal odor pleasantness of their children (N = 367; M = 9.3 years, SD = 6.4).
Results
Odor pleasantness was found to decrease as a function of children’s age. Neither sex of the parent nor sex of the child contributed significantly to this effect.
Conclusions
We propose that the effect of age-related changes on personal odor pleasantness reflects olfactory modulation of parental-child relationships.
Implications
Our study suggests that perception of young children’s personal odor as pleasant may contribute to bonding and thereby caretaking, which is needed to a lesser degree after puberty than before.
Parental caregiving is critical for the survival of our young and continuation of our species. In humans, visual and auditory signals from offspring have been shown to be potent facilitators of parenting. However, whether odors emitted by our young also influence human parenting remains unclear. To explore this, we conducted a series of questionnaire surveys targeting parents with children under 6 years old. First, we collected episodes on experiencing odors/sniffing various parts of a child’s body (n = 507). The prevalence of experiencing events described in those episodes was examined in a separate survey (n = 384). Based on those results, the Child Odor in Parenting scale (COPs) was developed, and subsequently used in the main survey (n = 888). We found COPs to have adequate content validity, concurrent validity, and reliability. Responses to the COPs demonstrated that parents, especially mothers with infants, are aware of odors from their offspring, and actively seek them in daily child-rearing. The factor structure and content of the COPs items indicated that child odors have both affective and instrumental roles. Affective experiences induce loving feeling and affectionate sniffing, while instrumental experiences pertain to specific hygienic needs. The head was the most frequent source of affective experiences, and the child’s bottom of instrumental. Each was experienced by more than 90% of the mothers with a child below 1 year of age. Affective experiences significantly declined as the child grew older, possibly associated with the decline of physical proximity between parents and child. This age-related decline was not prominent for instrumental experiences, except for the bottom, which significantly declined after 3 years of age. The present findings suggest that child odors play roles in human parenting, and that their nature and significance change during the course of a child’s development.
Studies in non-human mammals have identified olfactory signals as prime mediators of mother-infant bonding and they have been linked with maternal attitudes and behavior in our own species as well. However, although the neuronal network processing infant cues has been studied for visual and auditory signals; to date, no such information exists for chemosensory signals. We contrasted the cerebral activity underlying the processing of infant odor properties in 15 women newly given birth for the first time and 15 women not given birth while smelling the body odor of unfamiliar 2 day-old newborn infants. Maternal status-dependent activity was demonstrated in the thalamus when exposed to the body odor of a newly born infant. Subsequent regions of interest analyses indicated that dopaminergic neostriatal areas are active in maternal-dependent responses. Taken together, these data suggests that body odors from 2 day-old newborns elicit activation in reward-related cerebral areas in women, regardless of their maternal status. These tentative data suggests that certain body odors might act as a catalyst for bonding mechanisms and highlights the need for future research on odor-dependent mother-infant bonding using parametric designs controlling for biological saliency and general odor perception effects.
The role of olfaction in kin recognition and parental investment is documented in many mammalian/vertebrate species. Research
on humans, however, has only focused on whether parents are able to recognize their children by smell, not whether humans
use these cues for investment decisions. Here we show that fathers exhibit more affection and attachment and fewer ignoring
behaviors toward children whose smell they can identify than toward those whose smell they cannot recognize. Thus, olfaction
might serve as a means for males to determine their genetic relatedness to purported offspring. We also demonstrate that mothers’
olfactory recognition and hedonistic ratings are linked with the use of physical punishment. Mothers report using more punishment
with children whose odor they cannot recognize and less with children whose odor they rated as more pleasant. These results
provide the first preliminary evidence in humans that olfactory cues may guide parents in the allocation of care.
Background: There is a need in primary care for an easily administered instrument to give early indications of disorders in mother-infant relationships. Methods: An 84 item questionnaire was administered to 104 subjects, including normal mothers, depressed mothers with a normal mother-infant relationship and mothers with bonding disorders. A principle component analysis was used to select items for scale construction. Scale scores were compared with interview data. Reliability, sensitivity and specificity of the scales were measured. Findings: 4 factors of clinical relevance were obtained and used to construct 4 scales. The questionnaire was reduced to 25 questions. Scale 1 (impaired bonding) had a sensitivity of 0.93 in detecting mothers with bonding disorder. Scale 2 (rejection and anger) specifically identified mothers with severe disorders. Scale 3 may be useful in anxious mothers. Scale 4 signalled the presence of incipient abuse, requiring urgent intervention. Interpretation: This questionnaire can be used, with the Edinburgh Postnatal Depression Scale, by midwives and health visitors, for the early diagnosis of mother-infant bonding disorders.
This review summarises the psychiatry of the puerperium, in the light of publications during the past 5 years. A wide variety of disorders are seen. Recognition of disorders of the mother-infant relationship is important, because these have pernicious long-term effects but generally respond to treatment. Psychoses complicate about one in 1000 deliveries. The most common is related to manic depression, in which neuroleptic drugs should be used with caution. Post-traumatic stress disorder, obsessions of child harm, and a range of anxiety disorders all require specific psychological treatments. Postpartum depression necessitates thorough exploration. Cessation of breastfeeding is not necessary, because most antidepressant drugs seem not to affect the infant. Controlled trials have shown the benefit of involving the child's father in therapy and of interventions promoting interaction between mother and infant. Owing to its complexity, multidisciplinary specialist teams have an important place in postpartum psychiatry.
Cuteness in offspring is a potent protective mechanism that ensures survival for otherwise completely dependent infants. Previous research has linked cuteness to early ethological ideas of a 'Kindchenschema' (infant schema) where infant facial features serve as 'innate releasing mechanisms' for instinctual caregiving behaviours. We propose extending the concept of cuteness beyond visual features to include positive infant sounds and smells. Evidence from behavioural and neuroimaging studies links this extended concept of cuteness to simple 'instinctual' behaviours and to caregiving, protection, and complex emotions. We review how cuteness supports key parental capacities by igniting fast privileged neural activity followed by slower processing in large brain networks also involved in play, empathy, and perhaps even higher-order moral emotions.
Selective processing of environmental stimuli improves processing capacity and allows adaptive modulation of behavior. The thalamus provides an effective filter of central sensory information processing. As olfactory projections, however, largely bypass the thalamus, other filter mechanisms must consequently have evolved for the sense of smell. We investigated whether specific anosmia - the inability to perceive a specific odor whereas detection of other substances is unaffected - represents an effective peripheral filter of olfactory information processing.
In contrast to previous studies, we showed in a sample of 1600 normosmic subjects, that specific anosmia is by no means a rare phenomenon. Instead, while the affected odor is highly individual, the general probability of occurrence of specific anosmia is close to 1. In addition, 25 subjects performed daily olfactory training sessions with enhanced exposure to their particular “missing” smells for the duration of three months. This resulted in a significant improvement of sensitivity towards the respective specific odors.
We propose specific anosmia to occur as a rule, rather than an exception, in the sense of smell. The lack of perception of certain odors may constitute a flexible peripheral filter mechanism, which can be altered by exposure.
Grundproblematik und Fragestellung: In der deutschsprachigen Literatur gibt es kein valides Instrument zur Erfassung postpartal auftretender depressiver Störungen. Unser Anliegen war es, die »Edinburgh postnatal depression scale« (EPDS) in einer deutschsprachigen Übersetzung der Validierung und Reliabilitätsprüfung zu unterziehen.
Patienten und Methodik: Zufällig ausgewählte Wöchnerinnen (n = 110) nahmen nach Beantwortung der Fragen der EPDS an einem semistrukturierten Interview teil. Die Diagnostik einer depressiven Störung wurde nach den Forschungskriterien für psychische Störungen der ICD-10 durchgeführt. Die Validität der EPDS wurde der klinischen Diagnose einer Depression gegenübergestellt. Dabei erfolgte die Berechnung von Sensitivität, Spezifität und dem positiven Vorhersagewert bezogen auf die jeweiligen EPDS-Summenwerte. Zusätzlich wurde eine Reliabilitätsanalyse für die EPDS angeschlossen.
Ergebnisse: Das Durchschnittsalter der Wöchnerinnen betrug 28,6 Jahre, 72 % waren verheiratet und der Anteil an Erstgebärenden lag bei 45 %. Bei einem EPDS-Summenscore-Schwellenwert von 9,5 wurden eine Sensitivität von 0,96, eine Spezifität von 1 und ein positiver Vorhersagewert von ebenfalls 1 ermittelt. Die Reliabilitätsanalyse der EPDS ergab für die »Guttmann-Split-half-Reliabilität« einen Wert von 0,82 und für den α-Koeffizienten einen Wert von 0,81.
Folgerungen: Die deutschsprachige Fassung der EPDS mit zehn Fragen stellt ein »anwenderfreundliches« Inventar zur Unterstützung der Diagnostik einer depressiven Störung in der Postpartalperiode dar. Hinsichtlich Validität und Reliabilität ist das Testinstrument gut abgesichert. Die EPDS ist sowohl als klinisches Screeninginstrument als auch für die Anwendung im Forschungsbereich geeignet.
Background:
Isolated congenital anosmia is a disorder (ICA) characterized by not or only rudimentary developed central olfactory structures. This results in the lack of the sense of smell since birth. Although this phenomenon is known among clinicians almost no knowledge exists on how those people cope with the disorder.
Material and methods:
43 people with ICA were asked with a standardised questionnaire about when they fi rst noticed their disorder, how they experience the lack of smelling ability and about different aspects of daily life.
Results:
ICA is detected by the patients self or by their parents at the age of 10 in average. However about 13 years pass, until the right diagnosis is confirmed. In contrast to people with acquired olfactory loos ICA patients have developed strategies to adapt to the deficit in daily life. Nevertheless they report increased social insecurity and more hazardous events.
Conclusion:
The results can be of advantage for clinicians and patients to get a better understanding of the disorder.
Although referred to in passing in several places, there have been few attempts to specify the functions of the human olfactory system. This article presents an initial effort at identifying and categorizing these functions, using 3 sources of information as a guide: 1) losses experienced by anosmic participants; 2) olfactory function in other mammals; and 3) capacity, namely, whether the human olfactory system can support the suggested function and whether there is evidence that it does. Three major classes of function were identified, relating to Ingestion (Detection/identification prior to ingestion; Detection of expectancy violations; Appetite regulation; Breast orientation and feeding), Avoiding environmental hazards (Fear related; Disgust related), and Social communication (Reproductive [inbreeding avoidance, fitness detection in prospective mates]; Emotional contagion [fear contagion, stress buffering]). These suggested functions were then examined with respect to 1) issues of ecological validity in human olfactory research; 2) their impact on olfactory loss; and 3) their general and specific implications for the study of human olfaction. © The Author 2009. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: [email protected]
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We report that 90% of women tested in the present study identified their newborns by olfactory cues after only 10 min-1 hr exposure to their infants. All of the women tested recognized their babies' odor after exposure periods greater than 1 hr. The robust results are due in part to the implementation of an initial screening phase in which individuals with obvious olfactory deficits were excluded from the sample. These results suggest that odor cues from newborns are even more salient to their mothers than have been thought heretofore.
The role of olfactory cues in maternal recognition of neonates was investigated. Mothers were able to identify the garments worn by their own infants (in comparison to garments worn by unfamiliar infants) through odor alone within the first 6 days postpartum. In a second experiment, mothers who had only limited pre-test exposure to their infants recognized the odor of their infant's garment during tests conducted at 20.5-41.7 hr after delivery. Olfaction may be an especially salient modality for recognition of infants.
In this paper, we report new data on mutual olfactory recognition between mother and child. Newborn infants were filmed since birth. When awakening in the mother's room at the Clinical Hospital, they were confronted with a cotton pad impregnated with diverse secretions of the mother and a cotton pad impregnated with the same secretions of another mother or a pad with no specific odour. We used a double-blind technique. By analyzing the films, frame by frame, we found that the whole area swept by the nose and the arms was significantly decreased in the child whose nose came into contact with the "mother" pad. The method could be used to study other sensory abilities in the baby. The olfactory abilities of the mother in relation to the baby were also tested with the double-blind principle. We found (i) on the 3rd and 4th days after birth, most mothers recognized the baby's odour, (ii) this faculty decreased from the 4th to the 6th day, and finally (iii) increased from the 8th day. These results are discussed. We also found that one-third of 3 to 5 years old children more often chose a tee-shirt worn against the mother's skin for 2 to 3 days than any other tee-shirt (worn by an alien mother or with no specific odour). It appears that olfactory cues can play a role in the attachment of the baby to its mother, and that they still are involved in that process when the child is between 3 and 5 years old.
The auditory and olfactory discrimination ability of mothers, in relation to stimuli from their newborn infants, was concomitantly measured in a sample of 12 mother-newborn dyads during the 1st week after the child's birth. Both types of discrimination ability had a parallel evolution from one day to the next. The performances continued to increase from day to day, except on the 4th and 7th days. These 2 days corresponded to times when the mothers were more depressed. Half of the mothers were more skilled in one sensorial skill than the other.
'Sniffin' Sticks' is a new test of nasal chemosensory performance based on pen-like odor dispensing devices. It comprises three tests of olfactory function, namely tests for odor threshold (n-butanol, testing by means of a single staircase), odor discrimination (16 pairs of odorants, triple forced choice) and odor identification (16 common odorants, multiple forced choice from four verbal items per test odorant). After extensive preliminary investigations the tests were applied to a group of 104 healthy volunteers (52 female, 52 male, mean age 49.5 years, range 18-84 years) in order to establish test-retest reliability and to compare them with an established measure of olfactory performance (the Connecticut Chemosensory Clinical Research Center Test, CCCRC). Performance decreased with increasing age of the subjects (P < 0.001). Coefficients of correlation between sessions 1 and 2 were 0.61 for thresholds, 0.54 for discrimination and 0.73 for identification. Butanol thresholds as obtained with the CCCRC increased as a function of age; this relation to the subjects' age was not found for the CCCRC odor identification task. The test-retest reliability for CCCRC thresholds was 0.36, for odor identification it was 0.60. It is concluded that 'Sniffin' Sticks' may be suited for the routine clinical assessment of olfactory performance.
This paper describes severe, disorders of maternal affection and behaviour and suggests that there is an early process of mother-to-infant bonding which can go seriously wrong.
Forty-four self-selected women who had suffered from at least one episode of postnatal mental illness described an unexpected and often catastrophic failure to love one or more of their babies.
These women reported absent affection, sometimes hate, rejection, neglect or impulses to harm, in relation to at least one of their children. These feelings often began immediately or very shortly after the birth, and with one exception, were specific to one child; such characteristics are best encapsulated by the term 'maternal bonding disorder'. Twenty-nine of the women were multiparae; first-borns were not significantly more likely to be the focus for such feelings. There was no direct evidence of predisposing maternal personality traits or previous experiences. Postnatal mental illness and recalled severe pain during labour were significantly associated with such disorders which, in their severe forms, did not occur in the absence of postnatal mental illness.
The nature of the link between postnatal mental illness and disorders of maternal bonding remains unclear. Because, in multiparae, the disorder often 'missed' the first child, factors such as maternal personality traits or early childhood experiences cannot be regarded as sufficient causes.
Mothers' recognition of their newborns by olfactory cues. Developmental psychobiology
- M Kaitz
Kaitz, M., et al., Mothers' recognition of their newborns by olfactory cues.
Developmental psychobiology, 1987. 20(6): p. 587-591.
Evolution of maternal mood state and of the 13
- A.-S Cismaresco
- F Bonnin
Cismaresco, A.-S. and F. Bonnin, Evolution of maternal mood state and of the
13.