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Boot E, Levy A, Gaeta G, Gunasekara N, Parkkinen E, Kontaris E, Jacquot M, Tachtsidis I. fNIRS a novel neuroimaging tool to investigate olfaction, olfactory imagery, and crossmodal interactions: a systematic review. Front Neurosci 2024; 18:1266664. [PMID: 38356646 PMCID: PMC10864673 DOI: 10.3389/fnins.2024.1266664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 01/02/2024] [Indexed: 02/16/2024] Open
Abstract
Olfaction is understudied in neuroimaging research compared to other senses, but there is growing evidence of its therapeutic benefits on mood and well-being. Olfactory imagery can provide similar health benefits as olfactory interventions. Harnessing crossmodal visual-olfactory interactions can facilitate olfactory imagery. Understanding and employing these cross-modal interactions between visual and olfactory stimuli could aid in the research and applications of olfaction and olfactory imagery interventions for health and wellbeing. This review examines current knowledge, debates, and research on olfaction, olfactive imagery, and crossmodal visual-olfactory integration. A total of 56 papers, identified using the PRISMA method, were evaluated to identify key brain regions, research themes and methods used to determine the suitability of fNIRS as a tool for studying these topics. The review identified fNIRS-compatible protocols and brain regions within the fNIRS recording depth of approximately 1.5 cm associated with olfactory imagery and crossmodal visual-olfactory integration. Commonly cited regions include the orbitofrontal cortex, inferior frontal gyrus and dorsolateral prefrontal cortex. The findings of this review indicate that fNIRS would be a suitable tool for research into these processes. Additionally, fNIRS suitability for use in naturalistic settings may lead to the development of new research approaches with greater ecological validity compared to existing neuroimaging techniques.
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Affiliation(s)
| | - Andrew Levy
- Metabolight Ltd., London, United Kingdom
- Wellcome Centre for Human Neuroimaging, University College, London, United Kingdom
| | - Giuliano Gaeta
- Health and Well-being Centre of Excellence, Givaudan UK Limited, Ashford, United Kingdom
| | - Natalie Gunasekara
- Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - Emilia Parkkinen
- Health and Well-being Centre of Excellence, Givaudan UK Limited, Ashford, United Kingdom
| | - Emily Kontaris
- Health and Well-being Centre of Excellence, Givaudan UK Limited, Ashford, United Kingdom
| | - Muriel Jacquot
- Health and Well-being Centre of Excellence, Givaudan UK Limited, Ashford, United Kingdom
| | - Ilias Tachtsidis
- Metabolight Ltd., London, United Kingdom
- Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
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de Groot JHB, Beetsma DJV, van Aerts TJA, le Berre E, Gallagher D, Shaw E, Aarts H, Smeets MAM. From sterile labs to rich VR: Immersive multisensory context critical for odors to induce motivated cleaning behavior. Behav Res Methods 2020; 52:1657-1670. [PMID: 31965478 PMCID: PMC7406481 DOI: 10.3758/s13428-019-01341-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Extending traditional research methods for studying the effects of odor on behavior, this study applied virtual reality (VR) to create a real-world, immersive context that was compared with a traditional sterile, non-immersive lab setting. Using precise odor administration with olfactometry, participants were exposed to three odors (cleaning-related pleasant smell, cleaning-unrelated pleasant smell: vanillin, and odorless air). Our aim was to tease apart whether participants' motivation to clean was driven by cleaning associations and/or odor pleasantness, and how context would accentuate these effects. The results indeed showed that, in VR only, the cleaning-related smell elicited faster and more energetic cleaning behavior on a custom-designed cleaning task, and faster and more voluminous olfactory sampling compared with controls (vanillin, air). These effects were not driven by odor valence, given the general absence of significant differences between the pleasant control odor vanillin and odorless air. In sum, combining rigorous experimental control with high ecological validity, this research shows the context dependency of (congruent) odors affecting motivated behavior in an immersive context only.
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Affiliation(s)
- Jasper H B de Groot
- Department of Psychology, Utrecht University, PO Box 80140, 3508 TC, Utrecht, the Netherlands.
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA.
| | - Daniel J V Beetsma
- Department of Psychology, Utrecht University, PO Box 80140, 3508 TC, Utrecht, the Netherlands
| | - Theo J A van Aerts
- Department of Psychology, Utrecht University, PO Box 80140, 3508 TC, Utrecht, the Netherlands
| | | | | | | | - Henk Aarts
- Department of Psychology, Utrecht University, PO Box 80140, 3508 TC, Utrecht, the Netherlands
| | - Monique A M Smeets
- Department of Psychology, Utrecht University, PO Box 80140, 3508 TC, Utrecht, the Netherlands
- Unilever R&D, Vlaardingen, the Netherlands
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Speed LJ, Majid A. Linguistic features of fragrances: The role of grammatical gender and gender associations. Atten Percept Psychophys 2019; 81:2063-2077. [PMID: 31044396 PMCID: PMC6675776 DOI: 10.3758/s13414-019-01729-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Odors are often difficult to identify and name, which leaves them vulnerable to the influence of language. The present study tests the boundaries of the effect of language on odor cognition by examining the effect of grammatical gender. We presented participants with male and female fragrances paired with descriptions of masculine or feminine grammatical gender. In Experiment 1 we found that memory for fragrances was enhanced when the grammatical gender of a fragrance description matched the gender of the fragrance. In Experiment 2 we found memory for fragrances was affected by both grammatical gender and gender associations in fragrance descriptions - recognition memory for odors was higher when the gender was incongruent. In sum, we demonstrated that even subtle aspects of language can affect odor cognition.
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Affiliation(s)
- Laura J Speed
- Department of Psychology, University of York, York, UK.
- Centre for Language Studies, Radboud University, Nijmegen, The Netherlands.
| | - Asifa Majid
- Department of Psychology, University of York, York, UK
- Centre for Language Studies, Radboud University, Nijmegen, The Netherlands
- Max Planck Institute for Psycholinguistics, Nijmegen, The Netherlands
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Zhang Z, Zhang H, Zhang L, Guan C. Exploring Cortex Connectivity Signal in Sensory Response to Odors. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2019; 2019:1255-1258. [PMID: 31946120 DOI: 10.1109/embc.2019.8856506] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Recent neuroscience studies using fMRI have shown specific cortex activities are associated with scent stimuli. This has shed light on the use of EEG for investigating the neuronal processes and effects of olfactory sensory. While there were a few EEG studies using ERP or spectral power analysis, the results are often not converging or lack of generality. This study attempts to explore a potentially more generalized approach by looking into the connectivity patterns in the brain during olfactory sensing. Human olfactory system collects odorants and transduces them into neural signals which are transmitted to the olfactory bulb that connects to the orbitofrontal cortex for further processing. We study connectivity of cortex signal through the coherence analysis on scalp EEG data. We propose a novel protocol for robust olfactory stimulus identification and synchronization experiment. We adopt Magnitude Squared Coherence Estimation for coherence analysis and derived a coherence index (CI) to infer the collaborative effect derived from a region of interest, e.g., left side and right side of scalp. From the 14 subjects' EEG data, we observe the lateralization effect of olfactory processes in the human brain. The results suggest a stronger collaborative effect in the left hemisphere compare to the right side when pleasant stimuli are delivered.
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Singh AK, Touhara K, Okamoto M. Electrophysiological correlates of top-down attentional modulation in olfaction. Sci Rep 2019; 9:4953. [PMID: 30894641 PMCID: PMC6426950 DOI: 10.1038/s41598-019-41319-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 03/05/2019] [Indexed: 11/09/2022] Open
Abstract
The capacity to pay attention is important for the cognitive ability, for example, evaluating an object for its qualities. Attention can selectively prioritize the neural processes that are relevant to a given task. Neuroimaging investigations on human attention are primarily focused on vision to the exclusion of other sensory systems, particularly olfaction. Neural underpinnings of human olfactory attention are still not clearly understood. Here, we combined electroencephalographic measurements of olfactory event related potential with electrical neuroimaging to investigate how the neural responses after inhaling the same odor differ between conditions with varying levels of attention, and, in which brain areas. We examined the neural responses when participants attended to a rose-like odor of phenylethyl alcohol for evaluating its pleasantness versus its passive inhalation. Our results gathered significant evidence for attentional modulation of the olfactory neural response. The most prominent effect was found for the late positive component, P3, of olfactory event related potential within a second from the odor onset. The source reconstruction of this data revealed activations in a distributed network of brain regions predominantly in inferior frontal cortex, insula, and inferior temporal gyrus. These results suggest that the neuronal modulations from attention to olfactory pleasantness may be subserved by this network.
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Affiliation(s)
- Archana K Singh
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, 113-8657, Japan.
- ERATO Touhara Chemosensory Signal Project, JST, The University of Tokyo, Tokyo, Japan.
| | - Kazushige Touhara
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, 113-8657, Japan
- ERATO Touhara Chemosensory Signal Project, JST, The University of Tokyo, Tokyo, Japan
- International Research Center for Neurointelligence (WPI-IRCN), The University of Tokyo Institutes for Advanced Study, Tokyo, Japan
| | - Masako Okamoto
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, 113-8657, Japan.
- ERATO Touhara Chemosensory Signal Project, JST, The University of Tokyo, Tokyo, Japan.
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Van Gerven L, Alpizar YA, Steelant B, Callebaut I, Kortekaas Krohn I, Wouters M, Vermeulen F, Boeckxstaens G, Talavera K, Hellings PW. Enhanced chemosensory sensitivity in patients with idiopathic rhinitis and its reversal by nasal capsaicin treatment. J Allergy Clin Immunol 2017; 140:437-446.e2. [PMID: 28389389 DOI: 10.1016/j.jaci.2017.03.014] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2016] [Revised: 02/21/2017] [Accepted: 03/02/2017] [Indexed: 12/14/2022]
Abstract
BACKGROUND The therapeutic action of capsaicin treatment in patients with idiopathic rhinitis (IR) is based on ablation of the transient receptor potential cation channel subfamily V, receptor 1 (TRPV1)-substance P nociceptive signaling pathway. However, the functional consequences of capsaicin treatment on nasal nerve activation and the association between the reduction in nasal hyperreactivity (NHR) and response to capsaicin treatment remain unknown. OBJECTIVE We sought to study the effects of capsaicin nasal spray on the afferent innervation of the nasal mucosa by monitoring trigeminal nerve activity in patients with IR and healthy control (HC) subjects. METHODS A double-blind, placebo-controlled randomized trial with capsaicin nasal spray was performed involving 33 patients with IR and 12 HC subjects. Before and at 4, 12, and 26 weeks after treatment, nasal mucosal potentials (NMPs) were measured while exposing the nasal mucosa of patients with IR and HC subjects to aerosols with increasing doses of the chemical irritants allyl isothiocyanate (AITC; also known as mustard oil) or capsaicin. The threshold for each compound was determined for each subject. The results of the NMP measurements were evaluated in parallel with the therapeutic response, visual analog scale scores for nasal symptoms, self-reported NHR, and mRNA expression of PGP9.5; TRPV1; transient receptor potential cation channel subfamily A, receptor 1 (TRPA1); TRPV4; transient receptor potential cation channel subfamily M, member 8 (TRPM8); and nerve growth factor (NGF) in nasal biopsy specimens. RESULTS AITC turned out to be the best stimulus because the coughing induced by capsaicin interfered with measurements. At baseline, the threshold for evoking changes in NMPs based on AITC was significantly lower for patients with IR compared with HC subjects (P = .0423). Capsaicin treatment of IR patients increased the threshold for the response to AITC at 4 and 12 weeks compared with placebo (P = .0406 and P = .0325, respectively), which returned to baseline by week 26 (P = .0611). This increase correlated with changes in visual analog scale major symptom (P = .0004) and total symptom (P = .0018) scores. IR patients with self-reported NHR at baseline showed a trend to being better responders to capsaicin treatment compared with patients with IR but without NHR (P = .10). CONCLUSION The lower threshold for AITC based on NMPs in patients with IR compared with HC subjects and the increased threshold for AITC after capsaicin treatment in patients with IR demonstrate the crucial role of TRPA1 and TRPV1 in IR pathophysiology. The strong correlation between the increase in AITC threshold in patients with IR and symptom reduction after capsaicin treatment demonstrates the clinical relevance of these findings.
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Affiliation(s)
- Laura Van Gerven
- Clinical division of Otorhinolaryngology, Head & Neck Surgery, University Hospitals Leuven, Leuven, Belgium; Laboratory of Clinical Immunology, Department of Microbiology and Immunology, KU Leuven, Leuven, Belgium
| | - Yeranddy A Alpizar
- Laboratory for Ion Channel Research and TRP Research Platform Leuven (TRPLe), Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Brecht Steelant
- Laboratory of Clinical Immunology, Department of Microbiology and Immunology, KU Leuven, Leuven, Belgium
| | - Ina Callebaut
- Clinical division of Otorhinolaryngology, Head & Neck Surgery, University Hospitals Leuven, Leuven, Belgium
| | - Inge Kortekaas Krohn
- Laboratory of Clinical Immunology, Department of Microbiology and Immunology, KU Leuven, Leuven, Belgium
| | - Mira Wouters
- Translational Research Center for Gastrointestinal Disorders (TARGID), KU Leuven, Leuven, Belgium
| | - François Vermeulen
- Cystic Fibrosis Reference Centre, University Hospitals Leuven, Leuven, Belgium
| | - Guy Boeckxstaens
- Translational Research Center for Gastrointestinal Disorders (TARGID), KU Leuven, Leuven, Belgium
| | - Karel Talavera
- Laboratory for Ion Channel Research and TRP Research Platform Leuven (TRPLe), Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Peter W Hellings
- Clinical division of Otorhinolaryngology, Head & Neck Surgery, University Hospitals Leuven, Leuven, Belgium; Laboratory of Clinical Immunology, Department of Microbiology and Immunology, KU Leuven, Leuven, Belgium; Department of Otorhinolaryngology, University of Ghent, Ghent, Belgium; Department of Otorhinolaryngology, Academic Medical Center, Amsterdam, The Netherlands.
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Lorenzen A, Scholz-Hehn D, Wiesner CD, Wolff S, Bergmann TO, van Eimeren T, Lentfer L, Baving L, Prehn-Kristensen A. Chemosensory processing in children with attention-deficit/hyperactivity disorder. J Psychiatr Res 2016; 76:121-7. [PMID: 26926800 DOI: 10.1016/j.jpsychires.2016.02.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Revised: 02/12/2016] [Accepted: 02/12/2016] [Indexed: 11/18/2022]
Abstract
BACKGROUND In attention-deficit/hyperactivity disorder (ADHD) not only deficits in dopamine-related cognitive functioning have been found but also a lower dopamine-sensitive olfactory threshold. The aim of the present study was to proof that only olfactory but not trigeminal sensitivity is increased in ADHD. Structural magnetic resonance imaging (MRI) was used to show increased olfactory bulb (OB) volume- a structure which is strongly shaped by olfactory performance through the mechanism of neuroplasticity (e.g. synaptogenesis). To elucidate whether cortical mechanisms are involved in altered olfaction in ADHD, functional MRI (fMRI) was introduced. METHODS A total of 18 boys with ADHD and 17 healthy controls (aged 7-12) were included in the study. Olfactory as well as trigeminal detection thresholds were examined. OB sizes were measured by means of structural MRI and an analysis of effective functional (fMRI) coupling of primary olfactory cortex was conducted. The frontal piriform cortex (fPIR) was chosen as seed region because of its importance in processing both trigeminal and olfactory stimuli as well as having profound influence on inner OB-signaling. RESULTS Increased olfactory sensitivity as well as an increase in OB volume was found in ADHD. There were no group differences in sensitivity towards a trigeminal stimulus. Compared to healthy controls, the fPIR in ADHD was more positively coupled with structures belonging to the salience network during olfactory and, to a lesser extent, during trigeminal stimulation. CONCLUSIONS Olfactory functioning is superior in subjects with ADHD. The observed increase in OB volume may relate to higher olfactory sensitivity in terms of neuroplasticity. During the processing of chemosensory stimuli, the primary olfactory cortex in ADHD is differently coupled to higher cortical structures which might indicate an altered top-down influence on OB structure and function.
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Affiliation(s)
- Anna Lorenzen
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital Schleswig-Holstein, Niemannsweg 147, 24105, Kiel, Germany.
| | - Deborah Scholz-Hehn
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital Schleswig-Holstein, Niemannsweg 147, 24105, Kiel, Germany.
| | - Christian D Wiesner
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital Schleswig-Holstein, Niemannsweg 147, 24105, Kiel, Germany.
| | - Stephan Wolff
- Department of Neuroradiology, University Hospital Schleswig-Holstein, Arnold- Heller-Str. 3, 24105, Kiel, Germany.
| | - Til O Bergmann
- Department of Neurology & Stroke, and Hertie Institute for Clinical Brain Research, University of Tübingen, Ottfried-Müller-Str. 25, 72076, Tübingen, Germany; Institute for Medical Psychology and Behavioral Neurobiology, University of Tübingen, Ottfried-Müller-Str. 25, 72076, Tübingen, Germany; Institute of Psychology, Christian-Albrechts University of Kiel, Olshausenstr. 62, 24118, Kiel, Germany.
| | - Thilo van Eimeren
- Department of Nuclear Medicine, University Hospital, Kerpenerstr. 62, 50937, Cologne, Germany; Department of Neurology, University Hospital, Kerpenerstr. 62, 50937, Cologne, Germany.
| | - Luisa Lentfer
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital Schleswig-Holstein, Niemannsweg 147, 24105, Kiel, Germany.
| | - Lioba Baving
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital Schleswig-Holstein, Niemannsweg 147, 24105, Kiel, Germany.
| | - Alexander Prehn-Kristensen
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital Schleswig-Holstein, Niemannsweg 147, 24105, Kiel, Germany.
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Hoenen M, Müller K, Pause BM, Lübke KT. Fancy Citrus, Feel Good: Positive Judgment of Citrus Odor, but Not the Odor Itself, Is Associated with Elevated Mood during Experienced Helplessness. Front Psychol 2016; 7:74. [PMID: 26869973 PMCID: PMC4735708 DOI: 10.3389/fpsyg.2016.00074] [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: 07/30/2015] [Accepted: 01/13/2016] [Indexed: 11/15/2022] Open
Abstract
Aromatherapy claims that citrus essential oils exert mood lifting effects. Controlled studies, however, have yielded inconsistent results. Notably, studies so far did not control for odor pleasantness, although pleasantness is a critical determinant of emotional responses to odors. This study investigates mood lifting effects of d-(+)-limonene, the most prominent substance in citrus essential oils, with respect to odor quality judgments. Negative mood was induced within 78 participants using a helplessness paradigm (unsolvable social discrimination task). During this task, participants were continuously (mean duration: 19.5 min) exposed to d-(+)-limonene (n = 25), vanillin (n = 26), or diethyl phthalate (n = 27). Participants described their mood (Self-Assessment-Manikin, basic emotion ratings) and judged the odors’ quality (intensity, pleasantness, unpleasantness, familiarity) prior to and following the helplessness induction. The participants were in a less positive mood after the helplessness induction (p < 0.001), irrespective of the odor condition. Still, the more pleasant the participants judged the odors, the less effective the helplessness induction was in reducing happiness (p = 0.019). The results show no odor specific mood lifting effect of d-(+)-limonene, but indicate a positive effect of odor pleasantness on mood. The study highlights the necessity to evaluate odor judgments in aromatherapy research.
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Affiliation(s)
- Matthias Hoenen
- Institute of Experimental Psychology, Heinrich Heine University Düsseldorf Düsseldorf, Germany
| | - Katharina Müller
- Institute of Experimental Psychology, Heinrich Heine University DüsseldorfDüsseldorf, Germany; Federal Employment Agency GermanyNürnberg, Germany
| | - Bettina M Pause
- Institute of Experimental Psychology, Heinrich Heine University Düsseldorf Düsseldorf, Germany
| | - Katrin T Lübke
- Institute of Experimental Psychology, Heinrich Heine University Düsseldorf Düsseldorf, Germany
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Human amygdala activations during nasal chemoreception. Neuropsychologia 2015; 78:171-94. [PMID: 26459095 DOI: 10.1016/j.neuropsychologia.2015.10.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 08/25/2015] [Accepted: 10/06/2015] [Indexed: 02/07/2023]
Abstract
This review serves as a comprehensive discussion of chemosensory stimulation of the amygdala in healthy humans. Following an introduction of the neuroanatomy of chemosensory processing in primary and secondary olfactory structures, functional resonance magnetic imaging and positron imaging tomography studies are systematically categorized based on valence of stimuli, stimulus concentration, and paradigm-dependent amygdala activation. The amygdala shows patterns of lateralization due to stimulus valence. Main findings include pleasant odors being associated with bilateral or left amygdala activation, and unpleasant odors being associated with activation of the right amygdala, suggesting a crucial role of the right amygdala in evolutionary preservation. Potentially threatening social stimuli, however, might be processed apart from the olfactory system and tend to activate the left amygdala. Amygdala response to chemosensory stimuli correlated with simultaneous activation in the orbitofrontal cortex (OFC), piriform cortex (PC), and insula, suggesting a close-knit network of these areas during stimulus processing.
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Moran JK, Dietrich DR, Elbert T, Pause BM, Kübler L, Weierstall R. The Scent of Blood: A Driver of Human Behavior? PLoS One 2015; 10:e0137777. [PMID: 26397374 PMCID: PMC4580480 DOI: 10.1371/journal.pone.0137777] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 08/21/2015] [Indexed: 01/03/2023] Open
Abstract
The scent of blood is potentially one of the most fundamental and survival-relevant olfactory cues in humans. This experiment tests the first human parameters of perceptual threshold and emotional ratings in men and women of an artificially simulated smell of fresh blood in contact with the skin. We hypothesize that this scent of blood, with its association with injury, danger, death, and nutrition will be a critical cue activating fundamental motivational systems relating to either predatory approach behavior or prey-like withdrawal behavior, or both. The results show that perceptual thresholds are unimodally distributed for both sexes, with women being more sensitive. Furthermore, both women and men’s emotional responses to simulated blood scent divide strongly into positive and negative valence ratings, with negative ratings in women having a strong arousal component. For women, this split is related to the phase of their menstrual cycle and oral contraception (OC). Future research will investigate whether this split in both genders is context-dependent or trait-like.
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Affiliation(s)
- James K. Moran
- Department of Psychology, University of Konstanz, Konstanz, Baden-Württemberg, Germany
- * E-mail:
| | - Daniel R. Dietrich
- Department of Human and Environmental Toxicology, University of Konstanz, Konstanz, Baden-Württemberg, Germany
| | - Thomas Elbert
- Department of Psychology, University of Konstanz, Konstanz, Baden-Württemberg, Germany
| | - Bettina M. Pause
- Biological Psychology and Social Psychology, Heinrich-Heine University, Düsseldorf, North Rhine-Westphalia, Germany
| | - Lisa Kübler
- Department of Psychology, University of Konstanz, Konstanz, Baden-Württemberg, Germany
| | - Roland Weierstall
- Department of Psychology, University of Konstanz, Konstanz, Baden-Württemberg, Germany
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Lübke KT, Pause BM. Always follow your nose: the functional significance of social chemosignals in human reproduction and survival. Horm Behav 2015; 68:134-44. [PMID: 25637403 DOI: 10.1016/j.yhbeh.2014.10.001] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Revised: 10/02/2014] [Accepted: 10/06/2014] [Indexed: 12/22/2022]
Abstract
This article is part of a Special Issue "Chemosignals and Reproduction" Across phyla, chemosensory communication is crucial for mediating a variety of social behaviors, which form the basis for ontogenetic and phylogenetic survival. In the present paper, evidence on chemosensory communication in humans, with special reference to reproduction and survival, will be presented. First, the impact of chemosignals on human reproduction will be reviewed. Work will be presented, showing how chemosensory signals are involved in mate choice and partnership formation by communicating attractiveness and facilitating a partner selection, which is of evolutionary advantage, and furthermore providing information about the level of sexual hormones. In addition to direct effects on phylogenetic survival, chemosignals indirectly aid reproductive success by fostering harm protection. Results will be presented, showing that chemosensory communication aids the emotional bond between mother and child, which in turn motivates parental caretaking and protection, leading to infant survival. Moreover, the likelihood of group survival can be increased through the use of stress-related chemosignals. Stress-related chemosignals induce a stress-related physiology in the perceiver, thereby priming a fight-flight-response, which is necessary for an optimum adaption to environmental harm. Finally, effects of sexual orientation on chemosensory communication will be discussed in terms of their putative role in stabilizing social groups, which might indirectly provide harm protection and foster survival. An integrative model of the presented data will be introduced. In conclusion, an outlook, focusing on the involvement of chemosensory communication in human social behavior and illustrating a novel approach to the significance of chemosensory signals in human survival, will be given.
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Affiliation(s)
- Katrin T Lübke
- Department of Experimental Psychology, University of Düsseldorf, Düsseldorf, Germany.
| | - Bettina M Pause
- Department of Experimental Psychology, University of Düsseldorf, Düsseldorf, Germany.
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12
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A portable experimental apparatus for human olfactory fMRI experiments. J Neurosci Methods 2013; 218:29-38. [DOI: 10.1016/j.jneumeth.2013.04.021] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Revised: 04/23/2013] [Accepted: 04/24/2013] [Indexed: 11/18/2022]
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Pause BM, Zlomuzica A, Kinugawa K, Mariani J, Pietrowsky R, Dere E. Perspectives on episodic-like and episodic memory. Front Behav Neurosci 2013; 7:33. [PMID: 23616754 PMCID: PMC3629296 DOI: 10.3389/fnbeh.2013.00033] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Accepted: 04/06/2013] [Indexed: 11/30/2022] Open
Abstract
Episodic memory refers to the conscious recollection of a personal experience that contains information on what has happened and also where and when it happened. Recollection from episodic memory also implies a kind of first-person subjectivity that has been termed autonoetic consciousness. Episodic memory is extremely sensitive to cerebral aging and neurodegenerative diseases. In Alzheimer’s disease deficits in episodic memory function are among the first cognitive symptoms observed. Furthermore, impaired episodic memory function is also observed in a variety of other neuropsychiatric diseases including dissociative disorders, schizophrenia, and Parkinson disease. Unfortunately, it is quite difficult to induce and measure episodic memories in the laboratory and it is even more difficult to measure it in clinical populations. Presently, the tests used to assess episodic memory function do not comply with even down-sized definitions of episodic-like memory as a memory for what happened, where, and when. They also require sophisticated verbal competences and are difficult to apply to patient populations. In this review, we will summarize the progress made in defining behavioral criteria of episodic-like memory in animals (and humans) as well as the perspectives in developing novel tests of human episodic memory which can also account for phenomenological aspects of episodic memory such as autonoetic awareness. We will also define basic behavioral, procedural, and phenomenological criteria which might be helpful for the development of a valid and reliable clinical test of human episodic memory.
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Affiliation(s)
- Bettina M Pause
- Institute of Experimental Psychology, University of Düsseldorf Düsseldorf, Germany
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Huart C, Legrain V, Hummel T, Rombaux P, Mouraux A. Time-frequency analysis of chemosensory event-related potentials to characterize the cortical representation of odors in humans. PLoS One 2012; 7:e33221. [PMID: 22427997 PMCID: PMC3302858 DOI: 10.1371/journal.pone.0033221] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Accepted: 02/09/2012] [Indexed: 11/19/2022] Open
Abstract
Background The recording of olfactory and trigeminal chemosensory event-related potentials (ERPs) has been proposed as an objective and non-invasive technique to study the cortical processing of odors in humans. Until now, the responses have been characterized mainly using across-trial averaging in the time domain. Unfortunately, chemosensory ERPs, in particular, olfactory ERPs, exhibit a relatively low signal-to-noise ratio. Hence, although the technique is increasingly used in basic research as well as in clinical practice to evaluate people suffering from olfactory disorders, its current clinical relevance remains very limited. Here, we used a time-frequency analysis based on the wavelet transform to reveal EEG responses that are not strictly phase-locked to onset of the chemosensory stimulus. We hypothesized that this approach would significantly enhance the signal-to-noise ratio of the EEG responses to chemosensory stimulation because, as compared to conventional time-domain averaging, (1) it is less sensitive to temporal jitter and (2) it can reveal non phase-locked EEG responses such as event-related synchronization and desynchronization. Methodology/Principal Findings EEG responses to selective trigeminal and olfactory stimulation were recorded in 11 normosmic subjects. A Morlet wavelet was used to characterize the elicited responses in the time-frequency domain. We found that this approach markedly improved the signal-to-noise ratio of the obtained EEG responses, in particular, following olfactory stimulation. Furthermore, the approach allowed characterizing non phase-locked components that could not be identified using conventional time-domain averaging. Conclusion/Significance By providing a more robust and complete view of how odors are represented in the human brain, our approach could constitute the basis for a robust tool to study olfaction, both for basic research and clinicians.
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Affiliation(s)
- Caroline Huart
- Institute of Neuroscience, Université Catholique de Louvain, Brussels, Belgium.
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Lübke KT, Hoenen M, Pause BM. Differential processing of social chemosignals obtained from potential partners in regards to gender and sexual orientation. Behav Brain Res 2011; 228:375-87. [PMID: 22197679 DOI: 10.1016/j.bbr.2011.12.018] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2011] [Revised: 12/05/2011] [Accepted: 12/11/2011] [Indexed: 11/19/2022]
Abstract
On an individual level, human body odors carry information about whether a person is an eligible mate. The current studies investigate if body odors also transmit information about individuals being potential partners in more general terms, namely in regards to gender and sexual orientation. In study 1, 14 gay and 14 heterosexual men were presented with body odors obtained from potential partners (gay male and heterosexual female body odors, respectively) and heterosexual male body odor as a control. In study 2, 14 lesbian and 14 heterosexual women were presented with lesbian female and heterosexual male body odors representing body odors of potential partners, and heterosexual female body odor as a control. Central nervous processing was analyzed using chemosensory event-related potentials and current source density analysis (64-channel EEG recording). Gay and heterosexual men responded with shorter P2 latencies to the body odors of their preferred sexual partners, and lesbian women responded with shorter P2 latencies to body odors of their preferred gender. In response to heterosexual male body odors, lesbian women displayed the most pronounced P3 amplitude, and distinct neuronal activation in medial frontal and parietal neocortical areas. A similar pattern of neuronal activation was observed in gay men when presented with heterosexual male body odor. Both the early processing advantage (P2) for desirable partners' body odors as well as the enhanced evaluative processing (P3, CSD) of undesirable partners' body odors suggest that human body odors indeed carry information about individuals being potential partners in terms of gender and sexual orientation.
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Affiliation(s)
- Katrin T Lübke
- Department of Experimental Psychology, University of Duesseldorf, Universitaetsstraße 1, Duesseldorf, FRG, Germany.
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Cornell Karnekull S, Jonsson FU, Larsson M, Olofsson JK. Affected by Smells? Environmental Chemical Responsivity Predicts Odor Perception. Chem Senses 2011; 36:641-8. [DOI: 10.1093/chemse/bjr028] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Cortical hemodynamic responses to intravenous thiamine propyldisulphide administration detected by multichannel near infrared spectroscopy (NIRS) system. Brain Topogr 2011; 24:114-26. [PMID: 21445664 DOI: 10.1007/s10548-011-0179-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2011] [Accepted: 03/18/2011] [Indexed: 10/18/2022]
Abstract
Intravenous injection of thiamine propyldisulphide (TPD), which induces sensation of a garlic-like odor, has been used as a representative subjective olfactory test in Japan. However, cortical loci activated by TPD still remain unclear. We recorded cerebral hemodynamic responses (changes in Oxy-Hb concentrations) induced by TPD administration using whole-head multi-channel near infrared spectroscopy (NIRS) system based on 3D-MRIs. TPD as an odorant and saline as a control were injected from the cephalic vein in the left forearm in ten male normosmic (five young and five elderly) subjects and five dysosmic elderly patients. The all normosmic, but not dysosmic, subjects felt the garlic-like odor in the all TPD trials. There was no significant difference in hemodynamic responses between the young and elderly normosmic subjects. However, TPD injection induced significantly larger hemodynamic responses in the bilateral operculums, bilateral dorsolateral prefrontal cortices (PFC) and anteromedial PFC in the normosmic subjects, compared with saline injection. Onset latencies of these hemodynamic responses were significantly correlated with onset latencies of subjective odor sensation in the normosmic subjects. Comparison of hemodynamic responses between the normosmic and dysosmic subjects indicated a significant difference in the bilateral operculums. The results demonstrated that Oxy-Hb increases in the bilateral operculums reflected olfactory sensation induced by TPD injection. Consideration of a route for intravenous TPD to reach the olfactory mucosa suggests that these hemodynamic responses might be attributed to food-related retronasal olfactory responses to TPD.
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Kayser J, Tenke CE, Malaspina D, Kroppmann CJ, Schaller JD, Deptula A, Gates NA, Harkavy-Friedman JM, Gil R, Bruder GE. Neuronal generator patterns of olfactory event-related brain potentials in schizophrenia. Psychophysiology 2011; 47:1075-86. [PMID: 20456657 DOI: 10.1111/j.1469-8986.2010.01013.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
To better characterize neurophysiologic processes underlying olfactory dysfunction in schizophrenia, nose-referenced 30-channel electroencephalogram was recorded from 32 patients and 35 healthy adults (18 and 18 male) during detection of hydrogen sulfide (constant-flow olfactometer, 200 ms unirhinal exposure). Event-related potentials (ERPs) were transformed to reference-free current source density (CSD) waveforms and analyzed by unrestricted Varimax-PCA. Participants indicated when they perceived a high (10 ppm) or low (50% dilution) odor concentration. Patients and controls did not differ in detection of high (23% misses) and low (43%) intensities and also had similar olfactory ERP waveforms. CSDs showed a greater bilateral frontotemporal N1 sink (305 ms) and mid-parietal P2 source (630 ms) for high than low intensities. N1 sink and P2 source were markedly reduced in patients for high intensity stimuli, providing further neurophysiological evidence of olfactory dysfunction in schizophrenia.
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Affiliation(s)
- Jürgen Kayser
- Division of Cognitive Neuroscience, New York State Psychiatric Institute, New York, New York 10032, USA.
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Pause BM, Lübke K, Laudien JH, Ferstl R. Intensified neuronal investment in the processing of chemosensory anxiety signals in non-socially anxious and socially anxious individuals. PLoS One 2010; 5:e10342. [PMID: 20428249 PMCID: PMC2859067 DOI: 10.1371/journal.pone.0010342] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2009] [Accepted: 03/18/2010] [Indexed: 11/18/2022] Open
Abstract
Background The ability to communicate anxiety through chemosensory signals has been documented in humans by behavioral, perceptual and brain imaging studies. Here, we investigate in a time-sensitive manner how chemosensory anxiety signals, donated by humans awaiting an academic examination, are processed by the human brain, by analyzing chemosensory event-related potentials (CSERPs, 64-channel recording with current source density analysis). Methodology/Principal Findings In the first study cerebral stimulus processing was recorded from 28 non-socially anxious participants and in the second study from 16 socially anxious individuals. Each individual participated in two sessions, smelling sweat samples donated from either female or male donors (88 sessions; balanced session order). Most of the participants of both studies were unable to detect the stimuli olfactorily. In non-socially anxious females, CSERPs demonstrate an increased magnitude of the P3 component in response to chemosensory anxiety signals. The source of this P3 activity was allocated to medial frontal brain areas. In socially anxious females chemosensory anxiety signals require more neuronal resources during early pre-attentive stimulus processing (N1). The neocortical sources of this activity were located within medial and lateral frontal brain areas. In general, the event-related neuronal brain activity in males was much weaker than in females. However, socially anxious males processed chemosensory anxiety signals earlier (N1 latency) than the control stimuli collected during an ergometer training. Conclusions/Significance It is concluded that the processing of chemosensory anxiety signals requires enhanced neuronal energy. Socially anxious individuals show an early processing bias towards social fear signals, resulting in a repression of late attentional stimulus processing.
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Affiliation(s)
- Bettina M Pause
- Department of Experimental Psychology, University of Duesseldorf, Duesseldorf, Germany.
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