1
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Candia-Rivera D, Engelen T, Babo-Rebelo M, Salamone PC. Interoception, network physiology and the emergence of bodily self-awareness. Neurosci Biobehav Rev 2024; 165:105864. [PMID: 39208877 DOI: 10.1016/j.neubiorev.2024.105864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2024] [Revised: 08/06/2024] [Accepted: 08/23/2024] [Indexed: 09/04/2024]
Abstract
The interplay between the brain and interoceptive signals is key in maintaining internal balance and orchestrating neural dynamics, encompassing influences on perceptual and self-awareness. Central to this interplay is the differentiation between the external world, others and the self, a cornerstone in the construction of bodily self-awareness. This review synthesizes physiological and behavioral evidence illustrating how interoceptive signals can mediate or influence bodily self-awareness, by encompassing interactions with various sensory modalities. To deepen our understanding of the basis of bodily self-awareness, we propose a network physiology perspective. This approach explores complex neural computations across multiple nodes, shifting the focus from localized areas to large-scale neural networks. It examines how these networks operate in parallel with and adapt to changes in visceral activities. Within this framework, we propose to investigate physiological factors that disrupt bodily self-awareness, emphasizing the impact of interoceptive pathway disruptions, offering insights across several clinical contexts. This integrative perspective not only can enhance the accuracy of mental health assessments but also paves the way for targeted interventions.
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Affiliation(s)
- Diego Candia-Rivera
- Sorbonne Université, Paris Brain Institute (ICM), CNRS UMR7225, INSERM U1127, Hôpital de la Pitié-Salpêtrière AP-HP, Inria Paris, 75013, Paris, France.
| | - Tahnée Engelen
- Department of Psychology and Centre for Interdisciplinary Brain Research, University of Jyväskylä, Mattilanniemi 6, Jyväskylä FI-40014, Finland
| | - Mariana Babo-Rebelo
- Laboratory of Cognitive Neuroscience, Neuro-X Institute, Faculty of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Geneva, Switzerland
| | - Paula C Salamone
- Department of Biomedical and Clinical Sciences, Center for Social and Affective Neuroscience, Linköping University, Linköping, Sweden
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2
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Bratman GN, Bembibre C, Daily GC, Doty RL, Hummel T, Jacobs LF, Kahn PH, Lashus C, Majid A, Miller JD, Oleszkiewicz A, Olvera-Alvarez H, Parma V, Riederer AM, Sieber NL, Williams J, Xiao J, Yu CP, Spengler JD. Nature and human well-being: The olfactory pathway. SCIENCE ADVANCES 2024; 10:eadn3028. [PMID: 38748806 DOI: 10.1126/sciadv.adn3028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Accepted: 04/12/2024] [Indexed: 07/04/2024]
Abstract
The world is undergoing massive atmospheric and ecological change, driving unprecedented challenges to human well-being. Olfaction is a key sensory system through which these impacts occur. The sense of smell influences quality of and satisfaction with life, emotion, emotion regulation, cognitive function, social interactions, dietary choices, stress, and depressive symptoms. Exposures via the olfactory pathway can also lead to (anti-)inflammatory outcomes. Increased understanding is needed regarding the ways in which odorants generated by nature (i.e., natural olfactory environments) affect human well-being. With perspectives from a range of health, social, and natural sciences, we provide an overview of this unique sensory system, four consensus statements regarding olfaction and the environment, and a conceptual framework that integrates the olfactory pathway into an understanding of the effects of natural environments on human well-being. We then discuss how this framework can contribute to better accounting of the impacts of policy and land-use decision-making on natural olfactory environments and, in turn, on planetary health.
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Affiliation(s)
- Gregory N Bratman
- School of Environmental and Forest Sciences, University of Washington, Seattle, WA 98195, USA
- Department of Psychology, University of Washington, Seattle, WA 98195, USA
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA 98195, USA
| | - Cecilia Bembibre
- Institute for Sustainable Heritage, University College London, London, UK
| | - Gretchen C Daily
- Natural Capital Project, Stanford University, Stanford, CA 94305, USA
- Department of Biology, Stanford University, Stanford, CA 94305, USA
- Woods Institute, Stanford University, Stanford, CA 94305, USA
| | - Richard L Doty
- Smell and Taste Center, Department of Otorhinolaryngology: Head and Neck Surgery, University of Pennsylvania Perelman School of Medicine, Hospital of the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Thomas Hummel
- Interdisciplinary Center Smell and Taste, Department of Otorhinolaryngology, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Lucia F Jacobs
- Department of Psychology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Peter H Kahn
- School of Environmental and Forest Sciences, University of Washington, Seattle, WA 98195, USA
- Department of Psychology, University of Washington, Seattle, WA 98195, USA
| | - Connor Lashus
- School of Environmental and Forest Sciences, University of Washington, Seattle, WA 98195, USA
| | - Asifa Majid
- Department of Experimental Psychology, University of Oxford, Oxford, UK
| | | | - Anna Oleszkiewicz
- Interdisciplinary Center Smell and Taste, Department of Otorhinolaryngology, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
- Institute of Psychology, University of Wroclaw, Wrocław, Poland
| | | | | | - Anne M Riederer
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA 98195, USA
| | - Nancy Long Sieber
- T.H. Chan School of Public Health, Harvard University, Boston, MA 02115, USA
| | - Jonathan Williams
- Air Chemistry Department, Max Planck Institute for Chemistry, 55128 Mainz, Germany
- Climate and Atmosphere Research Center, The Cyprus Institute, Nicosia, Cyprus
| | - Jieling Xiao
- College of Architecture, Birmingham City University, Birmingham, UK
| | - Chia-Pin Yu
- School of Forestry and Resource Conservation, National Taiwan University, Taiwan
- The Experimental Forest, College of Bio-Resources and Agriculture, National Taiwan University, Taiwan
| | - John D Spengler
- T.H. Chan School of Public Health, Harvard University, Boston, MA 02115, USA
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3
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Schwambergová D, Třebická Fialová J, Havlíček J. Olfactory self-inspection: Own body odour provides cues to one's health and hygiene status. Physiol Behav 2024; 275:114449. [PMID: 38135110 DOI: 10.1016/j.physbeh.2023.114449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 12/01/2023] [Accepted: 12/19/2023] [Indexed: 12/24/2023]
Abstract
Olfactory self-inspection has been observed in various mammals, including humans. This behaviour can help individuals to monitor own state, including health and hygiene. This study's aim was to explore the frequency of sniffing particular body parts and investigate possible gender differences. Further, we tested a possible function of this behaviour, namely monitoring health and hygiene, by investigating associations between the frequency of self-sniffing and health, hygiene, and disgust sensitivity. Respondents completed an online survey on self-sniffing behaviour, health status, hygiene habits, and disgust sensitivity. Self-sniffing behaviour was investigated using a purpose-built inventory which explored the incidence and frequency of sniffing different parts of own body. Principal Component Analysis identified three main axes of self-sniffing behaviour: Social acceptability self-inspection, Intimate self-inspection, and Cosmetic self-inspection. Our results further show that respondents with lower standards of hygienic habits engage significantly more in intimate self-inspection (sniffing body parts such as genitals, anus, or navel). Interestingly, individuals who reported more frequent health issues sniff more frequently areas such as the armpits, feet, or own breath (Social acceptability self-inspection), probably to check for possible changes in smell due to illness. Our results indicate that olfactory self-inspection probably has several functions depending on the location from which the smell originates.
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Affiliation(s)
- Dagmar Schwambergová
- Department of Zoology, Faculty of Science, Charles University, Viničná 7, 128 00 Prague 2, Czech Republic.
| | - Jitka Třebická Fialová
- Department of Zoology, Faculty of Science, Charles University, Viničná 7, 128 00 Prague 2, Czech Republic
| | - Jan Havlíček
- Department of Zoology, Faculty of Science, Charles University, Viničná 7, 128 00 Prague 2, Czech Republic
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4
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Di Cicco F, Evans RL, James AG, Weddell I, Chopra A, Smeets MAM. Intrinsic and extrinsic factors affecting axillary odor variation. A comprehensive review. Physiol Behav 2023; 270:114307. [PMID: 37516230 DOI: 10.1016/j.physbeh.2023.114307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 07/14/2023] [Accepted: 07/27/2023] [Indexed: 07/31/2023]
Abstract
Humans produce odorous secretions from multiple body sites according to the microbiomic profile of each area and the types of secretory glands present. Because the axilla is an active, odor-producing region that mediates social communication via the sense of smell, this article focuses on the biological mechanisms underlying the creation of axillary odor, as well as the intrinsic and extrinsic factors likely to impact the odor and determine individual differences. The list of intrinsic factors discussed includes sex, age, ethnicity, emotions, and personality, and extrinsic factors include dietary choices, diseases, climate, and hygienic habits. In addition, we also draw attention to gaps in our understanding of each factor, including, for example, topical areas such as the effect of climate on body odor variation. Fundamental challenges and emerging research opportunities are further outlined in the discussion. Finally, we suggest guidelines and best practices based on the factors reviewed herein for preparatory protocols of sweat collection, data analysis, and interpretation.
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Affiliation(s)
- Francesca Di Cicco
- Faculty of Social and Behavioural Sciences, Utrecht University, Heidelberglaan 1, Utrecht, CS 3584, the Netherlands.
| | - Richard L Evans
- Unilever Research & Development, Port Sunlight Laboratory, Bebington, UK
| | - A Gordon James
- Unilever Research & Development, Colworth House, Sharnbrook, UK
| | - Iain Weddell
- Unilever Research & Development, Port Sunlight Laboratory, Bebington, UK
| | - Anita Chopra
- Unilever Research & Development, Port Sunlight Laboratory, Bebington, UK
| | - Monique A M Smeets
- Faculty of Social and Behavioural Sciences, Utrecht University, Heidelberglaan 1, Utrecht, CS 3584, the Netherlands; Unilever Research & Development, Rotterdam, the Netherlands
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5
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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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6
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de Groot JHB, Haertl T, Loos HM, Bachmann C, Kontouli A, Smeets MAM. Unraveling the universality of chemical fear communication: evidence from behavioral, genetic, and chemical analyses. Chem Senses 2023; 48:bjad046. [PMID: 37944028 PMCID: PMC10718800 DOI: 10.1093/chemse/bjad046] [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: 08/25/2023] [Indexed: 11/12/2023] Open
Abstract
Abundant evidence indicates that humans can communicate threat-related information to conspecifics through their body odors. However, prior research has been primarily conducted on Western (WEIRD) samples. In this study, we aimed to investigate whether threat-related information can be transmitted by individuals of East Asian descent who carry a single-nucleotide polymorphism (SNP) 538G → A in the ABCC11 gene, which significantly reduces (noticeable) body odor. To examine this, we recruited 18 self-identified male East Asian AA-homozygotes and 18 self-identified male Western individuals who were carriers of the functional G-allele. We collected samples of their fear-related and neutral body odors. Subsequently, we conducted a double-blind behavioral experiment in which we presented these samples to 69 self-identified female participants of Western Caucasian and East Asian backgrounds. The participants were asked to rate faces that were morphed between expressions of fear and disgust. Notably, despite the "odorless" phenotypical expression of the ABCC11-mutation in East Asians, their fear odor caused a perceptual fear bias in both East Asian and Caucasian receivers. This finding leaves open the possibility of universal fear chemosignaling. Additionally, we conducted exploratory chemical analysis to gain initial insights into the chemical composition of the body odors presented. In a subsequent pre-registered behavioral study (N = 33), we found that exposure to hexadecanoic acid, an abundant compound in the fear and neutral body odor samples, was sufficient to reproduce the observed behavioral effects. While exploratory, these findings provide insight into how specific chemical components can drive chemical fear communication.
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Affiliation(s)
- Jasper H B de Groot
- Behavioural Science Institute, Radboud University, Nijmegen, 6525 XZ, the Netherlands
| | - Tobias Haertl
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, 91054, Germany
| | - Helene M Loos
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, 91054, Germany
- Department of Chemistry and Pharmacy, Fraunhofer Institute for Process Engineering and Packaging, Freising 85354, Germany
| | - Christin Bachmann
- Department of Social, Health, & Organizational Psychology, Utrecht University, Utrecht, 3584 CS, the Netherlands
| | - Athanasia Kontouli
- Department of Social, Health, & Organizational Psychology, Utrecht University, Utrecht, 3584 CS, the Netherlands
| | - Monique A M Smeets
- Department of Social, Health, & Organizational Psychology, Utrecht University, Utrecht, 3584 CS, the Netherlands
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7
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Ravreby I, Snitz K, Sobel N. There is chemistry in social chemistry. SCIENCE ADVANCES 2022; 8:eabn0154. [PMID: 35749498 PMCID: PMC9232116 DOI: 10.1126/sciadv.abn0154] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 05/10/2022] [Indexed: 05/20/2023]
Abstract
Nonhuman terrestrial mammals sniff themselves and each other to decide who is friend or foe. Humans also sniff themselves and each other, but the function of this is unknown. Because humans seek friends who are similar to themselves, we hypothesized that humans may smell themselves and others to subconsciously estimate body odor similarity, which, in turn, may promote friendship. To test this, we recruited nonromantic same-sex friend dyads and harvested their body odor. We found that objective ratings obtained with an electronic nose, and subjective ratings obtained from independent human smellers converged to suggest that friends smell more similar to each other than random dyads. Last, we recruited complete strangers, smelled them with an electronic nose, and engaged them in nonverbal same-sex dyadic interactions. We observed that dyads who smelled more similar had more positive dyadic interactions. In other words, we could predict social bonding with an electronic nose. We conclude that there is indeed chemistry in social chemistry.
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8
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Eisenstein M. Sniffing out smell's effects on human behaviour. Nature 2022; 606:S18-S20. [PMID: 35732777 DOI: 10.1038/d41586-022-01632-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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9
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Human odor exploration behavior is influenced by olfactory function and interest in the sense of smell. Physiol Behav 2022; 249:113762. [PMID: 35219704 DOI: 10.1016/j.physbeh.2022.113762] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 02/15/2022] [Accepted: 02/23/2022] [Indexed: 12/21/2022]
Abstract
Olfaction plays an important role in social interaction. This study examined the influence of chemosensory and cognitive abilities on conscious odor sniffing behaviors in humans. Participants (N = 349) were surveyed using a questionnaire for the frequency of behaviors in terms of odor exploration from intrinsic and external sources. Chemosensory functions (e.g., odor identification, trigeminal sensitivity, taste functions, and nasal patency), self-reported olfactory function, and the subjective importance of olfaction were assessed. Hierarchical regression analyses demonstrate a strong impact of olfactory importance on odor exploration behavior. Both female gender and chemosensory function (odor identification ability and trigeminal sensitivity) had a positive impact on odor exploration behavior from individuals' own body and from external sources. Moreover, participants with dysosmia compared to those with normosmia showed less frequent odor exploration behaviors, while their behaviors were partly predicted by nasal patency. In conclusion, conscious olfactory exploration behaviors reflect the interest in the sense of smell and is strongly modulated by chemosensory function. In turn, individuals with lower olfactory sensitivity invest less in olfactory explorations.
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10
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Noto T, Zhou G, Yang Q, Lane G, Zelano C. Human Primary Olfactory Amygdala Subregions Form Distinct Functional Networks, Suggesting Distinct Olfactory Functions. Front Syst Neurosci 2021; 15:752320. [PMID: 34955769 PMCID: PMC8695617 DOI: 10.3389/fnsys.2021.752320] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 11/08/2021] [Indexed: 12/02/2022] Open
Abstract
Three subregions of the amygdala receive monosynaptic projections from the olfactory bulb, making them part of the primary olfactory cortex. These primary olfactory areas are located at the anterior-medial aspect of the amygdala and include the medial amygdala (MeA), cortical amygdala (CoA), and the periamygdaloid complex (PAC). The vast majority of research on the amygdala has focused on the larger basolateral and basomedial subregions, which are known to be involved in implicit learning, threat responses, and emotion. Fewer studies have focused on the MeA, CoA, and PAC, with most conducted in rodents. Therefore, our understanding of the functions of these amygdala subregions is limited, particularly in humans. Here, we first conducted a review of existing literature on the MeA, CoA, and PAC. We then used resting-state fMRI and unbiased k-means clustering techniques to show that the anatomical boundaries of human MeA, CoA, and PAC accurately parcellate based on their whole-brain resting connectivity patterns alone, suggesting that their functional networks are distinct, relative both to each other and to the amygdala subregions that do not receive input from the olfactory bulb. Finally, considering that distinct functional networks are suggestive of distinct functions, we examined the whole-brain resting network of each subregion and speculated on potential roles that each region may play in olfactory processing. Based on these analyses, we speculate that the MeA could potentially be involved in the generation of rapid motor responses to olfactory stimuli (including fight/flight), particularly in approach/avoid contexts. The CoA could potentially be involved in olfactory-related reward processing, including learning and memory of approach/avoid responses. The PAC could potentially be involved in the multisensory integration of olfactory information with other sensory systems. These speculations can be used to form the basis of future studies aimed at clarifying the olfactory functions of these under-studied primary olfactory areas.
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Affiliation(s)
- Torben Noto
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Guangyu Zhou
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Qiaohan Yang
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Gregory Lane
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Christina Zelano
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
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11
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Vielle C, Montanari C, Pelloux Y, Baunez C. Evidence for a vocal signature in the rat and its reinforcing effects: a key role for the subthalamic nucleus. Proc Biol Sci 2021; 288:20212260. [PMID: 34905707 PMCID: PMC8670952 DOI: 10.1098/rspb.2021.2260] [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: 10/19/2021] [Accepted: 11/23/2021] [Indexed: 12/24/2022] Open
Abstract
Although rodents have a well-structured vocal form of communication, like humans and non-human primates, there is, to date, no evidence for a vocal signature in the well-known 50- and 22-kHz ultrasonic vocalizations (USVs) emitted by rats. Here, we show that rats can recognize the identity of the USV emitter since they choose to preferentially self-administer playback of 50-kHz USVs emitted by a stranger rat over those of their cagemate. In a second experiment, we show that only stranger, but not familiar, 50-kHz USVs reduce cocaine self-administration. Finally, to study the neurobiological substrate of these processes, we have shown that subthalamic nucleus (STN)-lesioned rats did not lever press much for any USV playback, whatever their emotional valence, nor did they seem able to differentiate familiar from stranger peer. Advocating for the existence of a vocal signature in rats, these results highlight the importance of ultrasonic communication in the socio-affective influence of behaviour, such as the influence of proximal social factors on drug consumption and confirm the role of the STN on this influence.
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Affiliation(s)
- Cassandre Vielle
- Institut de Neurosciences de la Timone, UMR 7289 CNRS and Aix-Marseille Université, 27 Boulevard Jean Moulin, Marseille 13005, France
| | - Christian Montanari
- Institut de Neurosciences de la Timone, UMR 7289 CNRS and Aix-Marseille Université, 27 Boulevard Jean Moulin, Marseille 13005, France
| | - Yann Pelloux
- Institut de Neurosciences de la Timone, UMR 7289 CNRS and Aix-Marseille Université, 27 Boulevard Jean Moulin, Marseille 13005, France
| | - Christelle Baunez
- Institut de Neurosciences de la Timone, UMR 7289 CNRS and Aix-Marseille Université, 27 Boulevard Jean Moulin, Marseille 13005, France
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12
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Vielle C, Montanari C, Pelloux Y, Baunez C. Evidence for a vocal signature in the rat and its reinforcing effects: a key role for the subthalamic nucleus. Proc Biol Sci 2021; 288:20212260. [PMID: 34905707 PMCID: PMC8670952 DOI: 10.1098/rspb.2021.2260 10.1098/rspb.2021.2260] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 11/23/2021] [Indexed: 06/16/2024] Open
Abstract
Although rodents have a well-structured vocal form of communication, like humans and non-human primates, there is, to date, no evidence for a vocal signature in the well-known 50- and 22-kHz ultrasonic vocalizations (USVs) emitted by rats. Here, we show that rats can recognize the identity of the USV emitter since they choose to preferentially self-administer playback of 50-kHz USVs emitted by a stranger rat over those of their cagemate. In a second experiment, we show that only stranger, but not familiar, 50-kHz USVs reduce cocaine self-administration. Finally, to study the neurobiological substrate of these processes, we have shown that subthalamic nucleus (STN)-lesioned rats did not lever press much for any USV playback, whatever their emotional valence, nor did they seem able to differentiate familiar from stranger peer. Advocating for the existence of a vocal signature in rats, these results highlight the importance of ultrasonic communication in the socio-affective influence of behaviour, such as the influence of proximal social factors on drug consumption and confirm the role of the STN on this influence.
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Affiliation(s)
- Cassandre Vielle
- Institut de Neurosciences de la Timone, UMR 7289 CNRS and Aix-Marseille Université, 27 Boulevard Jean Moulin, Marseille 13005, France
| | - Christian Montanari
- Institut de Neurosciences de la Timone, UMR 7289 CNRS and Aix-Marseille Université, 27 Boulevard Jean Moulin, Marseille 13005, France
| | - Yann Pelloux
- Institut de Neurosciences de la Timone, UMR 7289 CNRS and Aix-Marseille Université, 27 Boulevard Jean Moulin, Marseille 13005, France
| | - Christelle Baunez
- Institut de Neurosciences de la Timone, UMR 7289 CNRS and Aix-Marseille Université, 27 Boulevard Jean Moulin, Marseille 13005, France
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Abstract
Abstract
Introduction
Research has provided evidence for the transfer of single emotions including anger, anxiety and happiness through olfactory chemosignals, yet no work has examined the role of odour function in the aggregation of more complex emotional states or in the emotional contagion process. The aim of the present study was to ascertain whether an individual’s tendency to experience emotional aggregation was affected by objective measures of their olfactory function and subjective self-assessments of the importance of their own olfactory system.
Methods
In this study (N = 70), participant pairs were first assessed individually for olfactory threshold and odour identification, then completed the Importance of Olfaction Questionnaire. Each pair subsequently took part in two collaborative tasks. Individual emotion measures were taken before, during and after the completion of the two tasks.
Results
Multilevel structural equation modelling revealed that individuals’ within-dyad positive emotional agreement scores were associated with both their ‘importance of olfaction’ scores and their olfactory function. A significant association was also found between olfactory performance and the Importance of Olfaction scores.
Conclusions
These results provide evidence that the subjective importance an individual assigns to their sense of smell can predict their susceptibility to experience emotional aggregation during active, collaborative tasks.
Implications
The findings suggest that individuals’ tendency and capability to detect and respond to emotional chemosignals, a process required for olfactory-facilitated emotional contagion, may be affected by individual differences in olfactory function and subjective attitudes toward olfaction.
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14
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Hartig R, Wolf D, Schmeisser MJ, Kelsch W. Genetic influences of autism candidate genes on circuit wiring and olfactory decoding. Cell Tissue Res 2021; 383:581-595. [PMID: 33515293 PMCID: PMC7872953 DOI: 10.1007/s00441-020-03390-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 12/10/2020] [Indexed: 12/24/2022]
Abstract
Olfaction supports a multitude of behaviors vital for social communication and interactions between conspecifics. Intact sensory processing is contingent upon proper circuit wiring. Disturbances in genetic factors controlling circuit assembly and synaptic wiring can lead to neurodevelopmental disorders, such as autism spectrum disorder (ASD), where impaired social interactions and communication are core symptoms. The variability in behavioral phenotype expression is also contingent upon the role environmental factors play in defining genetic expression. Considering the prevailing clinical diagnosis of ASD, research on therapeutic targets for autism is essential. Behavioral impairments may be identified along a range of increasingly complex social tasks. Hence, the assessment of social behavior and communication is progressing towards more ethologically relevant tasks. Garnering a more accurate understanding of social processing deficits in the sensory domain may greatly contribute to the development of therapeutic targets. With that framework, studies have found a viable link between social behaviors, circuit wiring, and altered neuronal coding related to the processing of salient social stimuli. Here, the relationship between social odor processing in rodents and humans is examined in the context of health and ASD, with special consideration for how genetic expression and neuronal connectivity may regulate behavioral phenotypes.
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Affiliation(s)
- Renée Hartig
- Department of Psychiatry & Psychotherapy, University Medical Center, Johannes Gutenberg-University, 55131, Mainz, Germany.,Focus Program Translational Neurosciences (FTN), University Medical Center, Johannes Gutenberg-University, 55131, Mainz, Germany.,Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, 68159, Mannheim, Germany.,Institute for Microscopic Anatomy and Neurobiology, University Medical Center, Johannes Gutenberg-University, 55131, Mainz, Germany
| | - David Wolf
- Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, 68159, Mannheim, Germany
| | - Michael J Schmeisser
- Focus Program Translational Neurosciences (FTN), University Medical Center, Johannes Gutenberg-University, 55131, Mainz, Germany.,Institute for Microscopic Anatomy and Neurobiology, University Medical Center, Johannes Gutenberg-University, 55131, Mainz, Germany
| | - Wolfgang Kelsch
- Department of Psychiatry & Psychotherapy, University Medical Center, Johannes Gutenberg-University, 55131, Mainz, Germany. .,Focus Program Translational Neurosciences (FTN), University Medical Center, Johannes Gutenberg-University, 55131, Mainz, Germany. .,Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, 68159, Mannheim, Germany.
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15
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Kir Y, Sayar-Akaslan D, Agtas-Ertan E, Kusman A, Baskak N, Baran Z, Munir K, Baskak B. Cortical activity during social acceptance and rejection task in social anxiety disorder: A controlled functional near infrared spectroscopy study. Prog Neuropsychopharmacol Biol Psychiatry 2021; 104:110012. [PMID: 32553940 DOI: 10.1016/j.pnpbp.2020.110012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 05/30/2020] [Accepted: 06/09/2020] [Indexed: 11/19/2022]
Abstract
BACKGROUND The cognitive and emotional vulnerability of individuals with social anxiety disorder (SAD) and their response to repeated experiences of social rejection and social acceptance are important factors for the emergence and maintenance of symptoms of the disorder. Functional neuroimaging studies of SAD reveal hyperactivity in regions involved in the fear circuit such as amygdala, insula, anterior cingulate, and prefrontal cortices (PFC) in response to human faces with negative emotions. Observation of brain activity, however, involving studies of responses to standardized human interaction of social acceptance and social rejection have been lacking. METHODS We compared a group of index subjects with SAD (N = 22, mean age:26.3 ± 5.4, female/male: 7/15) (SADG) with a group of healthy controls (CG) (N = 21, mean age:28.7 ± 4.5, female/male: 14/7) in measures of cortical activity during standardized experiences of human interaction involving social acceptance (SA) and social rejection (SR) video-simulated handshaking tasks performed by real actors. In a third, control condition (CC), the subjects were expected to press a switch button in an equivalent space. Subjects with a concurrent mood episode were excluded and the severity of subclinical depressive symptoms was controlled. 52-channel functional near-infrared spectroscopy (fNIRS) was used to measure cortical activity. RESULTS Activity was higher in the SAD subjects compared to healthy controls, in particular in channels that project to middle and superior temporal gyri (STG), frontal eye fields (FEF) and dorsolateral prefrontal cortex (DLPFC) in terms of both SA and SR conditions. Cortical activity during the CC was not different between the groups. Only in the SAD-group, activity in the pre-motor and supplementary motor cortices, inferior and middle temporal gyri and fronto-polar area was higher during the rejection condition than the other two conditions. Anxiety scores were correlated with activity in STG, DLPFC, FEF and premotor cortex, while avoidance scores were correlated with activity in STG and FEF. CONCLUSIONS SA and SR are represented differently in terms of cortical activity in SAD subjects compared to healthy controls. Higher activity in both social conditions in SAD subjects compared to controls may imply biological sensitivity to these experiences and may underscore the importance of increased cortical activity during social interaction experiences as a putative mediator of vulnerability to SAD. Higher cortical activity in the SADG may possibly indicate stronger need for inhibitory control mechanisms and higher recruitment of theory of mind functions during social stress. Higher activity during the SR compared to the SA condition in the SAD subjects may also suggest distinct processing of social cues, whether they involve acceptance or rejection.
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Affiliation(s)
- Yagmur Kir
- Ankara University, Department of Psychiatry, Brain Research Center, Ankara, Turkey
| | - Damla Sayar-Akaslan
- Ankara University, Department of Psychiatry, Brain Research Center, Ankara, Turkey
| | - Ece Agtas-Ertan
- Ankara University, Department of Psychiatry, Brain Research Center, Ankara, Turkey
| | - Adnan Kusman
- Ankara University, Department of Psychiatry, Brain Research Center, Ankara, Turkey
| | - Nilay Baskak
- Yenimahalle Hospital, Department of Psychiatry, Ankara, Turkey
| | - Zeynel Baran
- Hacettepe University, Department of Psychology, Ankara, Turkey
| | - Kerim Munir
- Harvard Medical School, Developmental Medicine Center, Boston Children's Hospital, Boston, USA
| | - Bora Baskak
- Ankara University, Department of Psychiatry, Brain Research Center, Ankara, Turkey; Neuroscience and Neurotechnology Center of Excellence (NÖROM), Ankara, Turkey.
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16
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Boesveldt S, Parma V. The importance of the olfactory system in human well-being, through nutrition and social behavior. Cell Tissue Res 2021; 383:559-567. [PMID: 33433688 PMCID: PMC7802608 DOI: 10.1007/s00441-020-03367-7] [Citation(s) in RCA: 59] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 11/25/2020] [Indexed: 12/13/2022]
Abstract
The human sense of smell is still much underappreciated, despite its importance for vital functions such as warning and protection from environmental hazards, eating behavior and nutrition, and social communication. We here approach olfaction as a sense of well-being and review the available literature on how the sense of smell contributes to building and maintaining well-being through supporting nutrition and social relationships. Humans seem to be able to extract nutritional information from olfactory food cues, which can trigger specific appetite and direct food choice, but may not always impact actual intake behavior. Beyond food enjoyment, as part of quality of life, smell has the ability to transfer and regulate emotional conditions, and thus impacts social relationships, at various stages across life (e.g., prenatal and postnatal, during puberty, for partner selection and in sickness). A better understanding of how olfactory information is processed and employed for these functions so vital for well-being may be used to reduce potential negative consequences.
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Affiliation(s)
- Sanne Boesveldt
- Division of Human Nutrition and Health, Wageningen University, Stippeneng 4, 6708, Wageningen, The Netherlands.
| | - Valentina Parma
- Department of Psychology, Temple University, 1701 North 13th Street, PA, 19122, Philadelphia, USA.
- Monell Chemical Senses Center, 3500 Market St., PA, Philadelphia, 19104, USA.
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17
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Sarkar A, Harty S, Johnson KVA, Moeller AH, Carmody RN, Lehto SM, Erdman SE, Dunbar RIM, Burnet PWJ. The role of the microbiome in the neurobiology of social behaviour. Biol Rev Camb Philos Soc 2020; 95:1131-1166. [PMID: 32383208 PMCID: PMC10040264 DOI: 10.1111/brv.12603] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 04/01/2020] [Accepted: 04/02/2020] [Indexed: 12/13/2022]
Abstract
Microbes colonise all multicellular life, and the gut microbiome has been shown to influence a range of host physiological and behavioural phenotypes. One of the most intriguing and least understood of these influences lies in the domain of the microbiome's interactions with host social behaviour, with new evidence revealing that the gut microbiome makes important contributions to animal sociality. However, little is known about the biological processes through which the microbiome might influence host social behaviour. Here, we synthesise evidence of the gut microbiome's interactions with various aspects of host sociality, including sociability, social cognition, social stress, and autism. We discuss evidence of microbial associations with the most likely physiological mediators of animal social interaction. These include the structure and function of regions of the 'social' brain (the amygdala, the prefrontal cortex, and the hippocampus) and the regulation of 'social' signalling molecules (glucocorticoids including corticosterone and cortisol, sex hormones including testosterone, oestrogens, and progestogens, neuropeptide hormones such as oxytocin and arginine vasopressin, and monoamine neurotransmitters such as serotonin and dopamine). We also discuss microbiome-associated host genetic and epigenetic processes relevant to social behaviour. We then review research on microbial interactions with olfaction in insects and mammals, which contribute to social signalling and communication. Following these discussions, we examine evidence of microbial associations with emotion and social behaviour in humans, focussing on psychobiotic studies, microbe-depression correlations, early human development, autism, and issues of statistical power, replication, and causality. We analyse how the putative physiological mediators of the microbiome-sociality connection may be investigated, and discuss issues relating to the interpretation of results. We also suggest that other candidate molecules should be studied, insofar as they exert effects on social behaviour and are known to interact with the microbiome. Finally, we consider different models of the sequence of microbial effects on host physiological development, and how these may contribute to host social behaviour.
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Affiliation(s)
- Amar Sarkar
- Trinity College, Trinity Street, University of Cambridge, Cambridge, CB2 1TQ, U.K.,Leverhulme Centre for Human Evolutionary Studies, Department of Archaeology, Fitzwilliam Street, University of Cambridge, Cambridge, CB2 1QH, U.K
| | - Siobhán Harty
- Institute of Neuroscience, Trinity College Dublin, Dublin 2, Dublin, Ireland.,School of Psychology, Trinity College Dublin, Dublin 2, Dublin, Ireland
| | - Katerina V-A Johnson
- Department of Experimental Psychology, Radcliffe Observatory Quarter, University of Oxford, Oxford, OX2 6GG, U.K.,Pembroke College, University of Oxford, Oxford, OX1 1DW, U.K.,Department of Psychiatry, Warneford Hospital, University of Oxford, Oxford, OX3 7JX, U.K
| | - Andrew H Moeller
- Department of Ecology and Evolutionary Biology, Corson Hall, Tower Road, Cornell University, Ithaca, NY, 14853, U.S.A
| | - Rachel N Carmody
- Department of Human Evolutionary Biology, Harvard University, Peabody Museum, 11 Divinity Avenue, Cambridge, Massachusetts, 02138, USA
| | - Soili M Lehto
- Psychiatry, University of Helsinki and Helsinki University Hospital, PL 590, FI-00029, Helsinki, Finland.,Department of Psychology and Logopedics, Faculty of Medicine, University of Helsinki, P.O. Box 6, FI-00014, Helsinki, Finland.,Institute of Clinical Medicine/Psychiatry, University of Eastern Finland, P.O. Box 1627, FI-70211, Kuopio, Finland
| | - Susan E Erdman
- Division of Comparative Medicine, Massachusetts Institute of Technology, Building 16-825, 77 Massachusetts Avenue, Cambridge, MA, 02139, U.S.A
| | - Robin I M Dunbar
- Department of Experimental Psychology, Radcliffe Observatory Quarter, University of Oxford, Oxford, OX2 6GG, U.K
| | - Philip W J Burnet
- Department of Psychiatry, Warneford Hospital, University of Oxford, Oxford, OX3 7JX, U.K
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18
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Wyatt TD. Reproducible research into human chemical communication by cues and pheromones: learning from psychology's renaissance. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190262. [PMID: 32306877 PMCID: PMC7209928 DOI: 10.1098/rstb.2019.0262] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/16/2020] [Indexed: 12/27/2022] Open
Abstract
Despite the lack of evidence that the 'putative human pheromones' androstadienone and estratetraenol ever were pheromones, almost 60 studies have claimed 'significant' results. These are quite possibly false positives and can be best seen as potential examples of the 'reproducibility crisis', sadly common in the rest of the life and biomedical sciences, which has many instances of whole fields based on false positives. Experiments on the effects of olfactory cues on human behaviour are also at risk of false positives because they look for subtle effects but use small sample sizes. Research on human chemical communication, much of it falling within psychology, would benefit from vigorously adopting the proposals made by psychologists to enable better, more reliable science, with an emphasis on enhancing reproducibility. A key change is the adoption of study pre-registration and/or Registered Reports which will also reduce publication bias. As we are mammals, and chemical communication is important to other mammals, it is likely that chemical cues are important in our behaviour and that humans may have pheromones, but new approaches will be needed to reliably demonstrate them. This article is part of the Theo Murphy meeting issue 'Olfactory communication in humans'.
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Affiliation(s)
- Tristram D Wyatt
- Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK
- Centre for Biodiversity and Environment Research, University College London, Gower Street, London WC1E 6BT, UK
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19
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Perl O, Mishor E, Ravia A, Ravreby I, Sobel N. Are humans constantly but subconsciously smelling themselves? Philos Trans R Soc Lond B Biol Sci 2020; 375:20190372. [PMID: 32306875 PMCID: PMC7209943 DOI: 10.1098/rstb.2019.0372] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/04/2020] [Indexed: 01/02/2023] Open
Abstract
All primates, including humans, engage in self-face-touching at very high frequency. The functional purpose or antecedents of this behaviour remain unclear. In this hybrid review, we put forth the hypothesis that self-face-touching subserves self-smelling. We first review data implying that humans touch their faces at very high frequency. We then detail evidence from the one study that implicated an olfactory origin for this behaviour: This evidence consists of significantly increased nasal inhalation concurrent with self-face-touching, and predictable increases or decreases in self-face-touching as a function of subliminal odourant tainting. Although we speculate that self-smelling through self-face-touching is largely an unconscious act, we note that in addition, humans also consciously smell themselves at high frequency. To verify this added statement, we administered an online self-report questionnaire. Upon being asked, approximately 94% of approximately 400 respondents acknowledged engaging in smelling themselves. Paradoxically, we observe that although this very prevalent behaviour of self-smelling is of concern to individuals, especially to parents of children overtly exhibiting self-smelling, the behaviour has nearly no traction in the medical or psychological literature. We suggest psychological and cultural explanations for this paradox, and end in suggesting that human self-smelling become a formal topic of investigation in the study of human social olfaction. This article is part of the Theo Murphy meeting issue 'Olfactory communication in humans'.
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Affiliation(s)
| | | | | | | | - Noam Sobel
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
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20
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Drea CM. Design, delivery and perception of condition-dependent chemical signals in strepsirrhine primates: implications for human olfactory communication. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190264. [PMID: 32306880 DOI: 10.1098/rstb.2019.0264] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The study of human chemical communication benefits from comparative perspectives that relate humans, conceptually and empirically, to other primates. All major primate groups rely on intraspecific chemosignals, but strepsirrhines present the greatest diversity and specialization, providing a rich framework for examining design, delivery and perception. Strepsirrhines actively scent mark, possess a functional vomeronasal organ, investigate scents via olfactory and gustatory means, and are exquisitely sensitive to chemically encoded messages. Variation in delivery, scent mixing and multimodality alters signal detection, longevity and intended audience. Based on an integrative, 19-species review, the main scent source used (excretory versus glandular) differentiates nocturnal from diurnal or cathemeral species, reflecting differing socioecological demands and evolutionary trajectories. Condition-dependent signals reflect immutable (species, sex, identity, genetic diversity, immunity and kinship) and transient (health, social status, reproductive state and breeding history) traits, consistent with socio-reproductive functions. Sex reversals in glandular elaboration, marking rates or chemical richness in female-dominant species implicate sexual selection of olfactory ornaments in both sexes. Whereas some compounds may be endogenously produced and modified (e.g. via hormones), microbial analyses of different odorants support the fermentation hypothesis of bacterial contribution. The intimate contexts of information transfer and varied functions provide important parallels applicable to olfactory communication in humans. This article is part of the Theo Murphy meeting issue 'Olfactory communication in humans'.
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Affiliation(s)
- Christine M Drea
- Department of Evolutionary Anthropology, Duke University, Durham, NC 27708-0383, USA.,Department of Biology, Duke University, Durham, NC 27708-0383, USA
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21
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Roberts SC, Havlíček J, Schaal B. Human olfactory communication: current challenges and future prospects. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190258. [PMID: 32306869 DOI: 10.1098/rstb.2019.0258] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Although anthropologists frequently report the centrality of odours in the daily lives and cultural beliefs of many small-scale communities, Western scholars have historically considered the sense of smell as minimally involved in human communication. Here, we suggest that the origin and persistence of this latter view might be a consequence of the fact that most research is conducted on participants from Western societies who, collectively, were rather old (adults), deodorized and desensitized (ODD) to various aspects of olfactory perception. The view is rapidly changing, however, and this themed issue provides a timely overview of the current state-of-the-art on human chemocommunication. Based on evolutionary models of communication, the papers cover both general mechanisms of odour production by 'senders' and odour perception by 'receivers'. Focus on specific functional contexts includes reciprocal impact of odours between infants and mothers, the role of odour in mate choice and how odours communicate emotion and disease. Finally, a position paper outlines pitfalls and opportunities for the future, against the context of the replication crisis in psychology. We believe a more nuanced view of human chemical communication is within our grasp if we can continue to develop inter-disciplinary insights and expand research activities beyond ODD people. This article is part of the Theo Murphy meeting issue 'Olfactory communication in humans'.
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Affiliation(s)
- S Craig Roberts
- Division of Psychology, University of Stirling, Stirling FK9 4LA, UK
| | - Jan Havlíček
- Faculty of Science, Charles University, Viničná 7, 128 42 Prague 2, Czech Republic
| | - Benoist Schaal
- Developmental Ethology and Cognitive Psychology Laboratory, Centre for Taste, Smell and Feeding Behaviour Science, UMR 6265 CNRS-Université de Bourgogne-Inra-AgroSup, Dijon, France
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22
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Ferdenzi C, Richard Ortegón S, Delplanque S, Baldovini N, Bensafi M. Interdisciplinary challenges for elucidating human olfactory attractiveness. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190268. [PMID: 32306873 DOI: 10.1098/rstb.2019.0268] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Many species use chemicals to communicate. In humans, there is increasing evidence that chemicals conveyed by the body are extremely important in interpersonal relationships. However, many aspects of chemical communication remain to be explored to fully understand this function in humans. The aim of this article is to identify relevant challenges in this field, with a focus on human attractiveness in the context of reproduction, and to put forward roadmaps for future studies that will hopefully extend to a wider range of social interactions. The first challenge consists in not being limited to body (mal)odours from the axilla. Preliminary data on how the odour of the face and head is perceived are presented. Second, there is a crucial need to increase our knowledge of the chemical bases of human chemical communication. Third, cross-cultural approaches must not be overlooked, because they have a major input in understanding the universal and culture-specific aspects of chemical communication. Fourth, the influence of specific cultural practices such as contraceptive and fragrance use is likely to be prominent and, therefore, needs to be well described. The fifth and last challenge for research projects in this field is the integration of different disciplines such as behavioural sciences, social sciences, neurosciences and microbiology. This article is part of the Theo Murphy meeting issue 'Olfactory communication in humans'.
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Affiliation(s)
- Camille Ferdenzi
- Centre de Recherche en Neurosciences de Lyon, CNRS UMR 5292, INSERM U1028, Université Claude Bernard Lyon 1, Centre Hospitalier Le Vinatier, F-69675 Bron Cedex, France
| | - Stéphane Richard Ortegón
- Centre de Recherche en Neurosciences de Lyon, CNRS UMR 5292, INSERM U1028, Université Claude Bernard Lyon 1, Centre Hospitalier Le Vinatier, F-69675 Bron Cedex, France
| | - Sylvain Delplanque
- Swiss Center for Affective Sciences, University of Geneva, CH-1202 Geneva, Switzerland
| | - Nicolas Baldovini
- Institut de Chimie de Nice, CNRS UMR 7272, Université Côte d'Azur, F-06108 Nice, France
| | - Moustafa Bensafi
- Centre de Recherche en Neurosciences de Lyon, CNRS UMR 5292, INSERM U1028, Université Claude Bernard Lyon 1, Centre Hospitalier Le Vinatier, F-69675 Bron Cedex, France
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23
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Abstract
Tears contain pheromones that trigger specific behavioral responses. In the mouse, male tear fluid is involved in long and short-term effects such as the receptive behavior and pregnancy block in females and the aggression in males. In contrast, pup tears exert an inhibitory effect on male mating behavior, also promoting sexual rejection in females. In the rat, a male lacrimal protein acts as an intraspecific and heterospecific signal enhancing sexual behavior in females and evoking avoidance behavior in mouse. However, behavioral effects of female tears on male behavior have yet to be described. Here, we report that female lacrimal fluid of different mouse strains contains a relatively small and involatile factor that abolishes inter-male aggression switching it into a copulatory behavior. The production of this molecule by the lacrimal glands is not affected by the estrous cycle but it is sensitive to ovariectomy, thus suggesting a control mediated by hormones. Moreover, this lacrimal anti-aggression pheromone modulates the activity of the lateral habenula, a brain area responsible for the valence of the aggressive interactions.
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24
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Gaby JM, Dalton P. Discrimination Between Individual Body Odors Is Unaffected by Perfume. Perception 2019; 48:1104-1123. [PMID: 31474186 DOI: 10.1177/0301006619872055] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Jessica M Gaby
- Monell Chemical Senses Center, Philadelphia, PA, USA; Department of Psychology, Cornell University, Ithaca, NY, USA; Department of Food Science, Penn State University, State College, PA, USA
| | - Pamela Dalton
- Monell Chemical Senses Center, Philadelphia, PA, USA
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25
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Zhou G, Lane G, Cooper SL, Kahnt T, Zelano C. Characterizing functional pathways of the human olfactory system. eLife 2019; 8:47177. [PMID: 31339489 PMCID: PMC6656430 DOI: 10.7554/elife.47177] [Citation(s) in RCA: 104] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 07/09/2019] [Indexed: 11/23/2022] Open
Abstract
The central processing pathways of the human olfactory system are not fully understood. The olfactory bulb projects directly to a number of cortical brain structures, but the distinct networks formed by projections from each of these structures to the rest of the brain have not been well-defined. Here, we used functional magnetic resonance imaging and k-means clustering to parcellate human primary olfactory cortex into clusters based on whole-brain functional connectivity patterns. Resulting clusters accurately corresponded to anterior olfactory nucleus, olfactory tubercle, and frontal and temporal piriform cortices, suggesting dissociable whole-brain networks formed by the subregions of primary olfactory cortex. This result was replicated in an independent data set. We then characterized the unique functional connectivity profiles of each subregion, producing a map of the large-scale processing pathways of the human olfactory system. These results provide insight into the functional and anatomical organization of the human olfactory system.
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Affiliation(s)
- Guangyu Zhou
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Gregory Lane
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Shiloh L Cooper
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Thorsten Kahnt
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, United States.,Department of Psychology, Weinberg College of Arts and Sciences, Northwestern University, Evanston, United States
| | - Christina Zelano
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, United States
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26
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Licon CC, Bosc G, Sabri M, Mantel M, Fournel A, Bushdid C, Golebiowski J, Robardet C, Plantevit M, Kaytoue M, Bensafi M. Chemical features mining provides new descriptive structure-odor relationships. PLoS Comput Biol 2019; 15:e1006945. [PMID: 31022180 PMCID: PMC6504111 DOI: 10.1371/journal.pcbi.1006945] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 05/07/2019] [Accepted: 03/11/2019] [Indexed: 12/30/2022] Open
Abstract
An important goal in researching the biology of olfaction is to link the perception of smells to the chemistry of odorants. In other words, why do some odorants smell like fruits and others like flowers? While the so-called stimulus-percept issue was resolved in the field of color vision some time ago, the relationship between the chemistry and psycho-biology of odors remains unclear up to the present day. Although a series of investigations have demonstrated that this relationship exists, the descriptive and explicative aspects of the proposed models that are currently in use require greater sophistication. One reason for this is that the algorithms of current models do not consistently consider the possibility that multiple chemical rules can describe a single quality despite the fact that this is the case in reality, whereby two very different molecules can evoke a similar odor. Moreover, the available datasets are often large and heterogeneous, thus rendering the generation of multiple rules without any use of a computational approach overly complex. We considered these two issues in the present paper. First, we built a new database containing 1689 odorants characterized by physicochemical properties and olfactory qualities. Second, we developed a computational method based on a subgroup discovery algorithm that discriminated perceptual qualities of smells on the basis of physicochemical properties. Third, we ran a series of experiments on 74 distinct olfactory qualities and showed that the generation and validation of rules linking chemistry to odor perception was possible. Taken together, our findings provide significant new insights into the relationship between stimulus and percept in olfaction. In addition, by automatically extracting new knowledge linking chemistry of odorants and psychology of smells, our results provide a new computational framework of analysis enabling scientists in the field to test original hypotheses using descriptive or predictive modeling. An important issue in olfaction sciences deals with the question of how a chemical information can be translated into percepts. This is known as the stimulus-percept problem. Here, we set out to better understand this issue by combining knowledge about the chemistry and cognition of smells with computational olfaction. We also assumed that not only one, but several physicochemical models may describe a given olfactory quality. To achieve this aim, a first challenge was to set up a database with ~1700 molecules characterized by chemical features and described by olfactory qualities (e.g. fruity, woody). A second challenge consisted in developing a computational model enabling the discrimination of olfactory qualities based on these chemical features. By meeting these 2 challenges, we provided for several olfactory qualities new chemical models describing why an odorant molecule smells fruity or woody (among others). For most qualities, multiple (rather than a single) chemical models were generated. These findings provide new elements of knowledge about the relationship between odorant chemistry and perception. They also make it possible to envisage concrete applications in the aroma and fragrance field where chemical characterization of smells is an important step in the design of new products.
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Affiliation(s)
- Carmen C. Licon
- Lyon Neuroscience Research Center, University Lyon, CNRS UMR5292, France
- Food Science and Nutrition Department, California State University, Fresno, California, United States of America
| | - Guillaume Bosc
- INSA Lyon, CNRS, LIRIS UMR5205, France
- Infologic, Bourg-lès-Valence, France
| | - Mohammed Sabri
- Lyon Neuroscience Research Center, University Lyon, CNRS UMR5292, France
- Ecole Nationale Polytechnique d’Oran—Maurice Audin, Département de Mathématiques et Informatique, Oran, Algérie
| | - Marylou Mantel
- Lyon Neuroscience Research Center, University Lyon, CNRS UMR5292, France
| | - Arnaud Fournel
- Lyon Neuroscience Research Center, University Lyon, CNRS UMR5292, France
| | - Caroline Bushdid
- Institute of Chemistry of Nice, UMR CNRS 7272, Université Côte d’Azur, Nice, France
| | - Jerome Golebiowski
- Institute of Chemistry of Nice, UMR CNRS 7272, Université Côte d’Azur, Nice, France
- Department of Brain & Cognitive Sciences, DGIST, Daegu, Republic of Korea
| | | | | | - Mehdi Kaytoue
- INSA Lyon, CNRS, LIRIS UMR5205, France
- Infologic, Bourg-lès-Valence, France
| | - Moustafa Bensafi
- Lyon Neuroscience Research Center, University Lyon, CNRS UMR5292, France
- * E-mail:
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27
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Abstract
Choosing food is not a trivial decision that people need to make daily, which is often subject to social influences. Here, we studied a human homolog of social transmission of food preference (STFP) as observed in rodents and other animals via chemosignals of body secretions. Human social chemosignals (sweat) produced during a disgust or neutral state among a group of donors were presented to participants undergoing a 2-alternative-forced-choice food healthiness judgment task during functional magnetic resonance imaging (fMRI). Response speed and two key signal detection indices—d’ (discrimination sensitivity) and β (response bias)—converged to indicate that social chemosignals of disgust facilitated food healthiness decisions, in contrast to primary disgust elicitors (disgust odors) that impaired the judgment. fMRI analyses (disgust vs. neutral sweat) revealed that the fusiform face area (FFA), amygdala, and orbitofrontal cortex (OFC) were engaged in processing social chemosignals of disgust during food judgment. Importantly, a double contrast of social signaling across modalities (olfactory vs. visual—facial expressions) indicated that the FFA and OFC exhibited preferential response to social chemosignals of disgust. Together, our findings provide initial evidence for human STFP, where social chemosignals are incorporated into food decisions by engaging social and emotional areas of the brain.
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28
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Abstract
It is commonly believed that humans have a poor sense of smell compared to other mammalian species. However, this idea derives not from empirical studies of human olfaction but from a famous 19th-century anatomist's hypothesis that the evolution of human free will required a reduction in the proportional size of the brain's olfactory bulb. The human olfactory bulb is actually quite large in absolute terms and contains a similar number of neurons to that of other mammals. Moreover, humans have excellent olfactory abilities. We can detect and discriminate an extraordinary range of odors, we are more sensitive than rodents and dogs for some odors, we are capable of tracking odor trails, and our behavioral and affective states are influenced by our sense of smell.
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Affiliation(s)
- John P McGann
- Behavioral and Systems Neuroscience, Psychology Department, Rutgers University, 152 Frelinghuysen Road, Piscataway, NJ 08854, USA.
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29
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Endevelt-Shapira Y, Perl O, Ravia A, Amir D, Eisen A, Bezalel V, Rozenkrantz L, Mishor E, Pinchover L, Soroka T, Honigstein D, Sobel N. Altered responses to social chemosignals in autism spectrum disorder. Nat Neurosci 2017; 21:111-119. [PMID: 29180748 DOI: 10.1038/s41593-017-0024-x] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 10/19/2017] [Indexed: 12/11/2022]
Abstract
Autism spectrum disorder (ASD) is characterized by impaired social communication, often attributed to misreading of emotional cues. Why individuals with ASD misread emotions remains unclear. Given that terrestrial mammals rely on their sense of smell to read conspecific emotions, we hypothesized that misreading of emotional cues in ASD partially reflects altered social chemosignaling. We found no difference between typically developed (TD) and cognitively able adults with ASD at explicit detection and perception of social chemosignals. Nevertheless, TD and ASD participants dissociated in their responses to subliminal presentation of these same compounds: the undetected 'smell of fear' (skydiver sweat) increased physiological arousal and reduced explicit and implicit measures of trust in TD but acted opposite in ASD participants. Moreover, two different undetected synthetic putative social chemosignals increased or decreased arousal in TD but acted opposite in ASD participants. These results implicate social chemosignaling as a sensory substrate of social impairment in ASD.
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Affiliation(s)
| | - Ofer Perl
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Aharon Ravia
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Daniel Amir
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Ami Eisen
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Vered Bezalel
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Liron Rozenkrantz
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Eva Mishor
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Liron Pinchover
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Timna Soroka
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | | | - Noam Sobel
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel.
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30
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A mammalian blood odor component serves as an approach-avoidance cue across phylum border - from flies to humans. Sci Rep 2017; 7:13635. [PMID: 29057956 PMCID: PMC5651850 DOI: 10.1038/s41598-017-13361-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 09/21/2017] [Indexed: 11/17/2022] Open
Abstract
Chemosignals are used by predators to localize prey and by prey to avoid predators. These cues vary between species, but the odor of blood seems to be an exception and suggests the presence of an evolutionarily conserved chemosensory cue within the blood odor mixture. A blood odor component, E2D, has been shown to trigger approach responses identical to those triggered by the full blood odor in mammalian carnivores and as such, is a key candidate as a food/alarm cue in blood. Using a multidisciplinary approach, we demonstrate that E2D holds the dual function of affecting both approach and avoidance behavior in a predator-prey predicted manner. E2D evokes approach responses in two taxonomically distant blood-seeking predators, Stable fly and Wolf, while evoking avoidance responses in the prey species Mouse. We extend this by demonstrating that this chemical cue is preserved in humans as well; E2D induces postural avoidance, increases physiological arousal, and enhances visual perception of affective stimuli. This is the first demonstration of a single chemical cue with the dual function of guiding both approach and avoidance in a predator-prey predicted manner across taxonomically distant species, as well as the first known chemosignal that affects both human and non-human animals alike.
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31
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A missense polymorphism in the putative pheromone receptor gene VN1R1 is associated with sociosexual behavior. Transl Psychiatry 2017; 7:e1102. [PMID: 28440809 PMCID: PMC5416707 DOI: 10.1038/tp.2017.70] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 01/09/2017] [Accepted: 02/10/2017] [Indexed: 01/05/2023] Open
Abstract
Pheromones regulate social and reproductive behavior in most mammalian species. These effects are mediated by the vomeronasal and main olfactory systems. Effects of putative pheromones on human neuroendocrine activity, brain activity and attractiveness ratings suggest that humans may communicate via similar chemosignaling. Here we studied two samples of younger and older individuals, respectively, with respect to one nonsynonymous polymorphism in the gene encoding the human vomeronasal type-1 receptor 1, VN1R1, and one nonsynonymous polymorphism in the gene encoding the olfactory receptor OR7D4. Participants in both samples had self-reported their sociosexual behavior using the sociosexual orientation inventory, including questions regarding lifetime number of one-night stands, number of partners last year and expected number of partners the coming 5 years. In women, there was a significant association between the VN1R1 polymorphism and sociosexual behavior in both samples, driven specifically by the question regarding one-night stands. Our results support the hypothesis that human social interaction is modulated by communication via chemosignaling.
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32
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Ferdenzi C, Rouby C, Bensafi M. The Social Nose: Importance of Olfactory Perception in Group Dynamics and Relationships. PSYCHOLOGICAL INQUIRY 2016. [DOI: 10.1080/1047840x.2016.1215207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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33
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Xiao YJ, Coppin G, Van Bavel JJ. Perceiving the World Through Group-Colored Glasses: A Perceptual Model of Intergroup Relations. PSYCHOLOGICAL INQUIRY 2016. [DOI: 10.1080/1047840x.2016.1199221] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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34
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Abstract
Early intervention improves prognosis in autism spectrum disorder, yet diagnosis is very difficult in preverbal children. A new study demonstrates that the automatic adjustments in sniffing patterns to pleasant and unpleasant odors may provide a window into early diagnosis.
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Affiliation(s)
- Dana M Small
- The John B Pierce Laboratory, New Haven, CT 06519, USA; Department of Psychiatry, Yale School of Medicine, New Haven, CT 06519, USA.
| | - Kevin A Pelphrey
- Center for Translational Developmental Neuroscience, Child Study Center, Yale School of Medicine, New Haven, CT 06519, USA
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35
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Perry A, Nichiporuk N, Knight RT. Where does one stand: a biological account of preferred interpersonal distance. Soc Cogn Affect Neurosci 2016; 11:317-26. [PMID: 26350617 PMCID: PMC4733343 DOI: 10.1093/scan/nsv115] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2015] [Revised: 08/11/2015] [Accepted: 09/01/2015] [Indexed: 11/14/2022] Open
Abstract
What determines how close you choose to stand to someone? Why do some people prefer farther distances than others? We hypothesized that an important factor is one's sensory sensitivity level, i.e. how sensitive one is to nearby visual stimulation, noise, touch or smell. This study characterizes the behavioral, hormonal and electrophysiological metrics of interpersonal distance (IPD) preferences in relation to levels of sensory sensitivity. Using both an ecologically realistic task and electroencephalogram (EEG), we found that sensory sensitivity levels predicted IPD preferences, such that the more sensitive one is the farther distance they prefer. Furthermore, electrophysiological evidence revealed that individuals with higher sensory sensitivity show more alpha suppression for approaching stimuli, strengthening the notion that early sensory cortical excitability is involved in one's social decision of how close to stand to another. The results provide evidence that a core human metric of social interaction is influenced by individual levels of sensory sensitivity.
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Affiliation(s)
- Anat Perry
- The Psychology Department and Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA
| | | | - Robert T Knight
- The Psychology Department and Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA
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36
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Mutic S, Moellers EM, Wiesmann M, Freiherr J. Chemosensory Communication of Gender Information: Masculinity Bias in Body Odor Perception and Femininity Bias Introduced by Chemosignals During Social Perception. Front Psychol 2016; 6:1980. [PMID: 26834656 PMCID: PMC4719098 DOI: 10.3389/fpsyg.2015.01980] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 12/10/2015] [Indexed: 11/29/2022] Open
Abstract
Human body odor is a source of important social information. In this study, we explore whether the sex of an individual can be established based on smelling axillary odor and whether exposure to male and female odors biases chemosensory and social perception. In a double-blind, pseudo-randomized application, 31 healthy normosmic heterosexual male and female raters were exposed to male and female chemosignals (odor samples of 27 heterosexual donors collected during a cardio workout) and a no odor sample. Recipients rated chemosensory samples on a masculinity-femininity scale and provided intensity, familiarity and pleasantness ratings. Additionally, the modulation of social perception (gender-neutral faces and personality attributes) and affective introspection (mood) by male and female chemosignals was assessed. Male and female axillary odors were rated as rather masculine, regardless of the sex of the donor. As opposed to the masculinity bias in the odor perception, a femininity bias modulating social perception appeared. A facilitated femininity detection in gender-neutral faces and personality attributes in male and female chemosignals appeared. No chemosensory effect on mood of the rater was observed. The results are discussed with regards to the use of male and female chemosignals in affective and social communication.
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Affiliation(s)
- Smiljana Mutic
- Diagnostic and Interventional Neuroradiology, Uniklinik RWTH Aachen Aachen, Germany
| | - Eileen M Moellers
- Diagnostic and Interventional Neuroradiology, Uniklinik RWTH Aachen Aachen, Germany
| | - Martin Wiesmann
- Diagnostic and Interventional Neuroradiology, Uniklinik RWTH Aachen Aachen, Germany
| | - Jessica Freiherr
- Diagnostic and Interventional Neuroradiology, Uniklinik RWTH Aachen Aachen, Germany
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37
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38
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Rozenkrantz L, Zachor D, Heller I, Plotkin A, Weissbrod A, Snitz K, Secundo L, Sobel N. A Mechanistic Link between Olfaction and Autism Spectrum Disorder. Curr Biol 2015; 25:1904-10. [PMID: 26144969 PMCID: PMC4518448 DOI: 10.1016/j.cub.2015.05.048] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2015] [Revised: 04/16/2015] [Accepted: 05/26/2015] [Indexed: 12/27/2022]
Abstract
Internal action models (IAMs) are brain templates for sensory-motor coordination underlying diverse behaviors [1]. An emerging theory suggests that impaired IAMs are a common theme in autism spectrum disorder (ASD) [2–4]. However, whether impaired IAMs occur across sensory systems and how they relate to the major phenotype of ASD, namely impaired social communication [5], remains unclear. Olfaction relies on an IAM known as the sniff response, where sniff magnitude is automatically modulated to account for odor valence [6–12]. To test the failed IAM theory in olfaction, we precisely measured the non-verbal non-task-dependent sniff response concurrent with pleasant and unpleasant odors in 36 children—18 with ASD and 18 matched typically developing (TD) controls. We found that whereas TD children generated a typical adult-like sniff response within 305 ms of odor onset, ASD children had a profoundly altered sniff response, sniffing equally regardless of odor valance. This difference persisted despite equal reported odor perception and allowed for 81% correct ASD classification based on the sniff response alone (binomial, p < 0.001). Moreover, increasingly aberrant sniffing was associated with increasingly severe ASD (r = −0.75, p < 0.001), specifically with social (r = −0.72, p < 0.001), but not motor (r < −0.38, p > 0.18), impairment. These results uncover a novel ASD marker implying a mechanistic link between the underpinnings of olfaction and ASD and directly linking an impaired IAM with impaired social abilities. Olfactory sniffing offers a language and task-free measure of autism and its severity Aberrant sniffing implicates sensory-motor loops at the mechanistic heart of autism Aberrant sniffing links sensory-motor impairments with social impairments in autism
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Affiliation(s)
- Liron Rozenkrantz
- Department of Neurobiology, Weizmann Institute of Science, 234 Herzel Street, Rehovot 76100, Israel.
| | - Ditza Zachor
- The Autism Center and Department of Pediatrics, Assaf Harofeh Medical Center, 1 Road 44, Zerifin 70300, Israel
| | - Iris Heller
- Department of Neurobiology, Weizmann Institute of Science, 234 Herzel Street, Rehovot 76100, Israel
| | - Anton Plotkin
- Department of Neurobiology, Weizmann Institute of Science, 234 Herzel Street, Rehovot 76100, Israel
| | - Aharon Weissbrod
- Department of Neurobiology, Weizmann Institute of Science, 234 Herzel Street, Rehovot 76100, Israel
| | - Kobi Snitz
- Department of Neurobiology, Weizmann Institute of Science, 234 Herzel Street, Rehovot 76100, Israel
| | - Lavi Secundo
- Department of Neurobiology, Weizmann Institute of Science, 234 Herzel Street, Rehovot 76100, Israel
| | - Noam Sobel
- Department of Neurobiology, Weizmann Institute of Science, 234 Herzel Street, Rehovot 76100, Israel.
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39
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Abstract
Sniffing our hand after a handshake may allow us to detect chemical signals produced by others.
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Affiliation(s)
- Gün R Semin
- Faculty of Social and Behavioral Sciences, Utrecht University, Utrecht, Netherlands; Koç University, Istanbul, Turkey and ISPA - Instituto Universitário, Lisbon, Portugal
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