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Schäfer L, Köppel C, Kreßner-Kiel D, Schwerdtfeger S, Michael M, Weidner K, Croy I. The scent of cuteness-neural signatures of infant body odors. Soc Cogn Affect Neurosci 2024; 19:nsae038. [PMID: 38850226 PMCID: PMC11192622 DOI: 10.1093/scan/nsae038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 04/05/2024] [Accepted: 06/06/2024] [Indexed: 06/10/2024] Open
Abstract
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 studies, we presented infantile and post-pubertal body odors to nulliparae and mothers (N = 78). All body odors increased blood-oxygen-level-dependent (BOLD) response and functional connectivity in circuits related to olfactory perception, pleasure and reward. Neural activation strength in pleasure and reward areas positively correlated with perceptual ratings across all participants. Compared to body odor of post-pubertal children, 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.
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Affiliation(s)
- Laura Schäfer
- Department of Psychotherapy and Psychosomatic Medicine, Faculty of Medicine and University Hospital Carl Gustav Carus, TUD Dresden University of Technology, Fetscherstraße 74, Dresden 01307, Germany
| | - Carina Köppel
- Department of Psychotherapy and Psychosomatic Medicine, Faculty of Medicine and University Hospital Carl Gustav Carus, TUD Dresden University of Technology, Fetscherstraße 74, Dresden 01307, Germany
- Department of Psychiatry and Psychotherapy, Charité—Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin 12203, Germany
| | - Denise Kreßner-Kiel
- Department of Psychotherapy and Psychosomatic Medicine, Faculty of Medicine and University Hospital Carl Gustav Carus, TUD Dresden University of Technology, Fetscherstraße 74, Dresden 01307, Germany
| | - Sarah Schwerdtfeger
- Department of Psychotherapy and Psychosomatic Medicine, Faculty of Medicine and University Hospital Carl Gustav Carus, TUD Dresden University of Technology, Fetscherstraße 74, Dresden 01307, Germany
| | - Marie Michael
- Max Planck School of Cognition, Leipzig 04103, Germany
- Department of Comparative Cultural Psychology, Max Planck Institute for Evolutionary Anthroplogy, Leipzig 04103, Germany
| | - Kerstin Weidner
- Department of Psychotherapy and Psychosomatic Medicine, Faculty of Medicine and University Hospital Carl Gustav Carus, TUD Dresden University of Technology, Fetscherstraße 74, Dresden 01307, Germany
| | - Ilona Croy
- Department of Psychotherapy and Psychosomatic Medicine, Faculty of Medicine and University Hospital Carl Gustav Carus, TUD Dresden University of Technology, Fetscherstraße 74, Dresden 01307, Germany
- Department of Clinical Psychology, Institute of Psychology, Friedrich-Schiller-Universität Jena, Jena 07737, Germany
- German Center for Mental Health (DZPG), Site Jena-Magdeburg-Halle 07737, Germany
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Owsienko D, Goppelt L, Hierl K, Schäfer L, Croy I, Loos HM. Body odor samples from infants and post-pubertal children differ in their volatile profiles. Commun Chem 2024; 7:53. [PMID: 38514840 PMCID: PMC10957943 DOI: 10.1038/s42004-024-01131-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 02/20/2024] [Indexed: 03/23/2024] Open
Abstract
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.
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Affiliation(s)
- Diana Owsienko
- Chair of Aroma and Smell Research, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Lisa Goppelt
- Chair of Aroma and Smell Research, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Katharina Hierl
- Department of Psychotherapy and Psychosomatics, Technical University of Dresden, Dresden, Germany
| | - Laura Schäfer
- Department of Psychotherapy and Psychosomatics, Technical University of Dresden, Dresden, Germany
| | - Ilona Croy
- Department of Psychotherapy and Psychosomatics, Technical University of Dresden, Dresden, Germany
- Department of Clinical Psychology, Friedrich-Schiller-University of Jena, Jena, Germany
| | - Helene M Loos
- Chair of Aroma and Smell Research, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany.
- Fraunhofer Institute for Process Engineering and Packaging IVV, Freising, Germany.
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Alahäivälä ALI, Thaploo D, Wein S, Seidel P, Riebel M, Hummel T, Schwarzbach JV. Inhalation-modulated detection of olfactory BOLD responses in the human brain. FRONTIERS IN NEUROIMAGING 2023; 2:1260893. [PMID: 38107774 PMCID: PMC10725246 DOI: 10.3389/fnimg.2023.1260893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 11/02/2023] [Indexed: 12/19/2023]
Abstract
Introduction In contrast to other sensory domains, detection of primary olfactory processes using functional magnetic resonance imaging has proven to be notably challenging with conventional block designs. This difficulty arises from significant habituation and hemodynamic responses in olfactory areas that do not appear to align with extended boxcar functions convolved with a generic hemodynamic response model. Consequently, some researchers have advocated for a transition to event-related designs, despite their known lower detection power compared to block designs. Methods Here, we conducted a block design experiment with 16s of continuous odorant stimulation alternating with 16s of continuous odorless air stimulation in 33 healthy participants. We compared four statistical analyses that relied either on standard block designs (SBD1-2) or on block designs that were modulated by the participants' individual breathing patterns (MBD1-2). Results We found that such modulated block designs were comparatively more powerful than standard block designs, despite having a substantially lower design efficiency. Using whole-brain effect size maps, we observed that the right insular and medial aspects of the left piriform cortex exhibited a preference for a breathing-modulated analysis approach. Discussion Research in olfaction that necessitates designs with longer-lasting blocks, such as those employed in the investigation of state-dependent processing, will benefit from the breathing-modulated analyses outlined in this study.
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Affiliation(s)
- Aino-Lotta I. Alahäivälä
- Biomedical Imaging Group, Department of Psychiatry and Psychotherapy, University of Regensburg, Regensburg, Germany
| | - Divesh Thaploo
- Interdisciplinary Center Smell and Taste, Department of Otorhinolaryngology, Technische Universität Dresden, Dresden, Germany
| | - Simon Wein
- Biomedical Imaging Group, Department of Psychiatry and Psychotherapy, University of Regensburg, Regensburg, Germany
| | - Philipp Seidel
- Biomedical Imaging Group, Department of Psychiatry and Psychotherapy, University of Regensburg, Regensburg, Germany
| | - Marco Riebel
- Biomedical Imaging Group, Department of Psychiatry and Psychotherapy, University of Regensburg, Regensburg, Germany
| | - Thomas Hummel
- Interdisciplinary Center Smell and Taste, Department of Otorhinolaryngology, Technische Universität Dresden, Dresden, Germany
| | - Jens Volkmar Schwarzbach
- Biomedical Imaging Group, Department of Psychiatry and Psychotherapy, University of Regensburg, Regensburg, Germany
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Loos HM, Schaal B, Pause BM, Smeets MAM, Ferdenzi C, Roberts SC, de Groot J, Lübke KT, Croy I, Freiherr J, Bensafi M, Hummel T, Havlíček J. Past, Present, and Future of Human Chemical Communication Research. PERSPECTIVES ON PSYCHOLOGICAL SCIENCE 2023:17456916231188147. [PMID: 37669015 DOI: 10.1177/17456916231188147] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/06/2023]
Abstract
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.
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Affiliation(s)
- Helene M Loos
- Department of Chemistry and Pharmacy, Friedrich-Alexander-Universität Erlangen-Nürnberg
- Department of Sensory Analytics and Technologies, Fraunhofer Institute for Process Engineering and Packaging IVV
| | - Benoist Schaal
- Development of Olfactory Cognition and Communication Lab, Centre des Sciences du Goût et de l'Alimentation, CNRS UMR 6265, Université de Bourgogne
| | - Bettina M Pause
- Department of Experimental Psychology, Heinrich-Heine-Universität Düsseldorf
| | | | - Camille Ferdenzi
- Centre de Recherche en Neurosciences de Lyon, CNRS UMR 5292, Inserm U1028, Université Claude Bernard Lyon 1, Centre Hospitalier Le Vinatier
| | | | | | - Katrin T Lübke
- Department of Experimental Psychology, Heinrich-Heine-Universität Düsseldorf
| | - Ilona Croy
- Institute for Psychology, Friedrich-Schiller-Universität Jena
| | - Jessica Freiherr
- Department of Sensory Analytics and Technologies, Fraunhofer Institute for Process Engineering and Packaging IVV
- Department of Psychiatry and Psychotherapy, Friedrich-Alexander-Universität Erlangen-Nürnberg
| | - Moustafa Bensafi
- Centre de Recherche en Neurosciences de Lyon, CNRS UMR 5292, Inserm U1028, Université Claude Bernard Lyon 1, Centre Hospitalier Le Vinatier
| | - Thomas Hummel
- Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden
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Croy I, Bierling A. Smells as Communication Pathways - why Emotions Pass through the Nose. Laryngorhinootologie 2023; 102:S93-S100. [PMID: 37130533 DOI: 10.1055/a-1935-3214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
For many species, the sense of smell is the most important sensory system for interacting with the environment and conspecifics. In contrast, the role of perception and communication of chemosensory information in humans has long been underestimated. The human sense of smell was considered less reliable, so that it was given less importance compared to visual and auditory sensory impressions. For some time now, a growing branch of research has been dealing with the role of the sense of sell in emotion and social communication, which is often only perceived subconsciously. This connection will be examine in more detail in this article. First, he basics regarding the structure and function of our olfactory system will be described for better understanding and classification. Then, with this background knowledge, the significance of olfaction for interpersonal communication and emotions will be discussed. Finally, we conclude that people suffering from olfactory disorders have specific impairments in their quality of life.
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Affiliation(s)
- Ilona Croy
- Institut für Klinische Psychologie, Friedrich-Schiller-Universität Jena
- Klinik für Psychotherapie und Psychosomatik, Universitätsklinikum Carl Gustav Carus Dresden
| | - Antonie Bierling
- Institut für Klinische Psychologie, Friedrich-Schiller-Universität Jena
- Klinik für Psychotherapie und Psychosomatik, Universitätsklinikum Carl Gustav Carus Dresden
- Institut für Materialwissenschaft und Nanotechnik, Technische Universität Dresden
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Hierl K, Croy I, Schäfer L. Body Odours Sampled at Different Body Sites in Infants and Mothers-A Comparison of Olfactory Perception. Brain Sci 2021; 11:820. [PMID: 34205665 PMCID: PMC8235221 DOI: 10.3390/brainsci11060820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 06/16/2021] [Accepted: 06/18/2021] [Indexed: 11/16/2022] Open
Abstract
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.
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Affiliation(s)
- Katharina Hierl
- Department of Psychotherapy and Psychosomatics, Technical University of Dresden, 01062 Dresden, Germany
| | - Ilona Croy
- Department of Biological and Clinical Psychology, Friedrich-Schiller-University of Jena, 07743 Jena, Germany
| | - Laura Schäfer
- Department of Psychotherapy and Psychosomatics, Technical University of Dresden, 01062 Dresden, Germany
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Schäfer L, Schriever VA, Croy I. Human olfactory dysfunction: causes and consequences. Cell Tissue Res 2021; 383:569-579. [PMID: 33496882 PMCID: PMC7835667 DOI: 10.1007/s00441-020-03381-9] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 12/06/2020] [Indexed: 01/08/2023]
Abstract
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.
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Affiliation(s)
- Laura Schäfer
- Klinik Und Poliklinik Für Psychotherapie Und Psychosomatik, Medizinische Fakultät Carl Gustav Carus, Technische Universität, Dresden, Germany
| | - Valentin A Schriever
- Abteilung Neuropädiatrie, Klinik Und Poliklinik Für Kinder- Und Jugendmedizin, Medizinische Fakultät Carl Gustav Carus, Technische Universität, Dresden, Germany
| | - Ilona Croy
- Klinik Und Poliklinik Für Psychotherapie Und Psychosomatik, Medizinische Fakultät Carl Gustav Carus, Technische Universität, Dresden, Germany.
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