Localizing the human brain response to olfactory stimulation: A meta-analytic approach

Torske, A.; Koch, Kathrin; Eickhoff, Simon B.; Freiherr, Jessica

doi:10.1016/j.neubiorev.2021.12.035

Cited by 15 publications

(16 citation statements)

References 122 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Finally, we did not use odors spanning the entire pleasantness scale (i.e., from lowest to highest pleasantness), which should be a target for future studies. Meta‐analysis study in olfaction showed that pleasant odor activated both right and left AMG (Torske et al., 2022 ). Activation of the AMG by pleasant odors might depend on complex interactions among odor intensity, arousal (Sorokowska et al., 2016 ), and odor memory; future research aiming to understand how interactions between the AMG and frontal regions influence odor processing should take this into account.…”

Section: Discussionmentioning

confidence: 99%

Role of the amygdala‐medial orbitofrontal relationship in odor recognition in the elderly

et al. 2023

View full text Add to dashboard Cite

Introduction In patients with mild cognitive impairment, pathological changes begin in the amygdala (AMG) and hippocampus (HI), especially in the parahippocampal gyrus and entorhinal cortex (ENT). These areas play an important role in olfactory detection and recognition. It is important to understand how subtle signs of olfactory disability relate to the functions of the above‐mentioned regions, as well as the orbitofrontal cortex (OFC). In this study, we evaluated brain activation using functional magnetic resonance imaging (fMRI), performed during the presentation of olfactory stimuli (classified as “normal odors” not inducing memory retrieval), and investigated the relationships of the blood oxygen level‐dependent (BOLD) signal with olfactory detection and recognition abilities in healthy elderly subjects. Methods Twenty‐four healthy elderly subjects underwent fMRI during olfaction, and raw mean BOLD signals were extracted from regions of interest, including bilateral regions (AMG, HI, parahippocampus, and ENT) and orbitofrontal subregions (frontal inferior OFC, frontal medial OFC, frontal middle OFC, and frontal superior OFC). Multiple regression and path analyses were conducted to understand the roles of these areas in olfactory detection and recognition. Results Activation of the left AMG had the greatest impact on olfactory detection and recognition, while the ENT, parahippocampus, and HI acted as a support system for AMG activation. Less activation of the right frontal medial OFC was associated with good olfactory recognition. These findings improve our understanding of the roles of limbic and prefrontal regions in olfactory awareness and identification in elderly individuals. Conclusion Functional decline of the ENT and parahippocampus crucially impacts olfactory recognition. However, AMG function may compensate for deficits through connections with frontal regions.

show abstract

Section: Discussionmentioning

confidence: 99%

Role of the amygdala‐medial orbitofrontal relationship in odor recognition in the elderly

et al. 2023

View full text Add to dashboard Cite

show abstract

“…Future studies using different TMS and EEG paradigms are needed to further investigate this research hypothesis. A recent meta-analysis investigating the brain activation during perception of pleasant odor across studies indicated consistent activation of bilateral amygdala, orbitofrontal cortex (OFC), piriform cortex, insula, pallidum, putamen, and the central operculum ( Torske et al, 2022 ). According to this activation pattern, it is likely that the hedonic encoding activates both the reward system ( Okuda et al, 2003 ) and the corticostriatal loops subserving the stimulus-action-dependent reward circuits ( Haruno and Kawato, 2006 ; Smith et al, 2009 ) which may explain the corticospinal activation to pleasantness we recorded.…”

Section: Discussionmentioning

confidence: 99%

Motor Cortex Response to Pleasant Odor Perception and Imagery: The Differential Role of Personality Dimensions and Imagery Ability

Infortuna

Gualano

Freedberg

et al. 2022

Front. Hum. Neurosci.

View full text Add to dashboard Cite

BackgroundNeuroimaging 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 MethodsWe 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.ResultsThe 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).ConclusionBoth 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.

show abstract

“…Coordinates or clusters based on previous studies can be used to functionally define a region-of-interest, but this method will likely bias toward results associated with the specific methods used to collect the data. Meta-analyses like activation likelihood estimation (ALE) maps will lead to more robust functional ROI definitions ( Veldhuizen et al, 2011a ; Seubert et al, 2013 ; Yeung et al, 2017 ; Torske et al, 2021 ). Particularly promising are ROI’s derived from large dataset connectomic analyses, which has recently been done for the olfactory cortical network with the Human Connectome Project data, as described in more detail above ( Arnold et al, 2020 ).…”

Section: Challenges To Chemosensory Connectome Neuroimaging Studiesmentioning

confidence: 99%

“…This account can then be cited in a manuscript submitted for publication and easily inspected by reviewers, editors, and readers. The field of human chemosensory perception and neuroimaging has recently shown an accelerated pace in the adoption of these practices ( Havermans and Hendriks, 2020 ; Parma et al, 2020 ; Iravani et al, 2021b ; Thunell et al, 2021 ; Torske et al, 2021 ). In absence of a pre-registration, an alternative solution is to be transparent about post hoc analyses and to perform the appropriate corrections for multiple comparisons.…”

Section: Best Practices From the Connectomics Fieldmentioning

confidence: 99%

Future Directions for Chemosensory Connectomes: Best Practices and Specific Challenges

Veldhuizen

Cecchetto

Fjældstad

et al. 2022

Front. Syst. Neurosci.

View full text Add to dashboard Cite

Ecological chemosensory stimuli almost always evoke responses in more than one sensory system. Moreover, any sensory processing takes place along a hierarchy of brain regions. So far, the field of chemosensory neuroimaging is dominated by studies that examine the role of brain regions in isolation. However, to completely understand neural processing of chemosensation, we must also examine interactions between regions. In general, the use of connectivity methods has increased in the neuroimaging field, providing important insights to physical sensory processing, such as vision, audition, and touch. A similar trend has been observed in chemosensory neuroimaging, however, these established techniques have largely not been rigorously applied to imaging studies on the chemical senses, leaving network insights overlooked. In this article, we first highlight some recent work in chemosensory connectomics and we summarize different connectomics techniques. Then, we outline specific challenges for chemosensory connectome neuroimaging studies. Finally, we review best practices from the general connectomics and neuroimaging fields. We recommend future studies to develop or use the following methods we perceive as key to improve chemosensory connectomics: (1) optimized study designs, (2) reporting guidelines, (3) consensus on brain parcellations, (4) consortium research, and (5) data sharing.

show abstract

Localizing the human brain response to olfactory stimulation: A meta-analytic approach

Cited by 15 publications

References 122 publications

Role of the amygdala‐medial orbitofrontal relationship in odor recognition in the elderly

Role of the amygdala‐medial orbitofrontal relationship in odor recognition in the elderly

Motor Cortex Response to Pleasant Odor Perception and Imagery: The Differential Role of Personality Dimensions and Imagery Ability

Future Directions for Chemosensory Connectomes: Best Practices and Specific Challenges

Contact Info

Product

Resources

About