1
|
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.
Collapse
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
| |
Collapse
|
2
|
Infortuna C, Gualano F, Freedberg D, Patel SP, Sheikh AM, Muscatello MRA, Bruno A, Mento C, Chusid E, Han Z, Thomas FP, Battaglia F. Motor Cortex Response to Pleasant Odor Perception and Imagery: The Differential Role of Personality Dimensions and Imagery Ability. Front Hum Neurosci 2022; 16:943469. [PMID: 35903786 PMCID: PMC9314567 DOI: 10.3389/fnhum.2022.943469] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 06/17/2022] [Indexed: 12/03/2022] Open
Abstract
Background Neuroimaging studies have shown a complex pattern of brain activation during perception of a pleasant odor and during its olfactory imagery. To date, little is known regarding changes in motor cortex excitability during these tasks. Bergamot essential oil (BEO) is extensively used in perfumes and cosmetics for its pleasantness. Therefore, to further our understanding of the human sense of smell, this study aimed to investigate the effect of perception and imagery of a pleasant odor (BEO) on motor cortex using Transcranial magnetic stimulation (TMS). Materials and Methods We examined the primary motor cortex (M1) excitability during perception of a pleasant odor (BEO) or perception of odorless saline (experiment 1). Furthermore, we tested the effect of olfactory imagery (OI) of BEO on corticospinal excitability (experiment 2). The increase in motor evoked potential (MEP) amplitude was correlated with personality dimensions scores, pleasantness, vividness, and general imagery ability. Results The results indicate that the corticospinal excitability changed after both perception and imagery of a pleasant odor (BEO). The correlation analysis shows an association with neuroticism personality trait (experiment 1) and with general olfactory imagery ability (experiment 2). Conclusion Both perception of a pleasant odor and its olfactory imagery modulate motor cortex excitability. The enhanced brain activation is affected by specific individual characteristics. Overall, our findings provide physiological evidence for a complex interaction between the olfactory and motor systems.
Collapse
Affiliation(s)
- Carmenrita Infortuna
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, Policlinico Universitario “G. Martino”, University of Messina, Messina, Italy
| | - Francesca Gualano
- Department of Medical Sciences, Hackensack Meridian School of Medicine, Nutley, NJ, United States
- Department of Neurology, Hackensack Meridian School of Medicine, Nutley, NJ, United States
| | - David Freedberg
- Department of Art History and Archeology, Italian Academy for Advanced Studies, Columbia University, New York, NY, United States
| | - Sapan P. Patel
- Department of Art History and Archeology, Italian Academy for Advanced Studies, Columbia University, New York, NY, United States
| | - Asad M. Sheikh
- Department of Pre-Clinical Sciences, New York College of Podiatric Medicine, New York, NY, United States
| | - Maria Rosaria Anna Muscatello
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, Policlinico Universitario “G. Martino”, University of Messina, Messina, Italy
| | - Antonio Bruno
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, Policlinico Universitario “G. Martino”, University of Messina, Messina, Italy
| | - Carmela Mento
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, Policlinico Universitario “G. Martino”, University of Messina, Messina, Italy
| | - Eileen Chusid
- Department of Pre-Clinical Sciences, New York College of Podiatric Medicine, New York, NY, United States
| | - Zhiyong Han
- Department of Medical Sciences, Hackensack Meridian School of Medicine, Nutley, NJ, United States
| | - Florian P. Thomas
- Department of Neurology, Hackensack Meridian School of Medicine, Nutley, NJ, United States
| | - Fortunato Battaglia
- Department of Medical Sciences, Hackensack Meridian School of Medicine, Nutley, NJ, United States
- Department of Neurology, Hackensack Meridian School of Medicine, Nutley, NJ, United States
- *Correspondence: Fortunato Battaglia,
| |
Collapse
|