Improved low-cost, MR-compatible olfactometer to deliver tobacco smoke odor

Lowen, Steven B.; Farmer, Stacey; Lukas, Scott E.

doi:10.3758/s13428-016-0709-1

Cited by 8 publications

(6 citation statements)

References 23 publications

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“…Such components were used in a series of pioneering modern olfactometers in the late 1980s ( Kobal and Hummel 1988 ), and versions of these remain commercially available to this day ( Vigouroux et al 2005 ; Cohen et al 2019 ). Several groups that developed conceptually similar devices, concentrated on affordability, and on magnetic resonance imaging (MRI) compatibility ( Sobel et al 1997 ; Lorig et al 1999 ; Johnson et al 2003 ; Lowen and Lukas 2006 ; Lundström et al 2010 ; Sommer et al 2012 ; Bestgen et al 2016 ; Lowen et al 2017 ; Hosseini et al 2020 ). The latter is becoming essential, as MRI is now the primary tool for investigating function in the intact human brain, and to investigate olfactory function, we need MRI-compatible olfactometers.…”

Section: Introductionmentioning

confidence: 99%

Odor Canopy: A Method for Comfortable Odorant Delivery in MRI

et al. 2021

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Functional magnetic resonance imaging (fMRI) has become the leading method for measuring the human brain response to sensory stimuli. However, olfaction fMRI lags behind vision and audition fMRI for two primary reasons: First, the olfactory brain areas are particularly susceptible to imaging artefacts, and second, the olfactory stimulus is particularly difficult to control in the fMRI environment. A component of the latter is related to the odorant-delivery human-machine interface, namely the point where odorants exit the dispensing apparatus to reach at the nose. Previous approaches relied on either nasal cannulas or nasal masks, each associated with particular drawbacks and discomforts. Here we provide detailed descriptions and instructions for transforming the MRI head-coil into an olfactory microenvironment, or odor canopy, where odorants can be switched on and off in less than 150 milliseconds without cannula or mask. In a proof-of-concept experiment we demonstrate that odor canopy provides for clearly dissociable odorant presence and absence, with no non-olfactory cues. Moreover, we find that odor canopy is rated more comfortable than nasal-mask, and we demonstrate that using odor canopy in the fMRI generates a typical olfactory brain-response. We conclude in recommending this approach for minimized discomfort in fMRI of olfaction.

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Section: Introductionmentioning

confidence: 99%

Odor Canopy: A Method for Comfortable Odorant Delivery in MRI

et al. 2021

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“…One group has published two technical papers 15 , 16 describing an MRI compatible ventilation system to enable smoking during functional imaging, however they have never presented any fMRI data collected using the device. Another recent paper 17 describes an MR-compatible olfactometer designed to deliver the odour of a burning cigarette to participants. Both these accounts use specialist equipment to mitigate some of the practical difficulties of smoking within an MRI scanner.…”

Section: Introductionmentioning

confidence: 99%

Investigating the neural correlates of smoking: Feasibility and results of combining electronic cigarettes with fMRI

Wall

Lyons

et al. 2017

Sci Rep

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Cigarette addiction is driven partly by the physiological effects of nicotine, but also by the distinctive sensory and behavioural aspects of smoking, and understanding the neural effects of such processes is vital. There are many practical difficulties associated with subjects smoking in the modern neuroscientific laboratory environment, however electronic cigarettes obviate many of these issues, and provide a close simulation of smoking tobacco cigarettes. We have examined the neural effects of ‘smoking’ electronic cigarettes with concurrent functional Magnetic Resonance Imaging (fMRI). The results demonstrate the feasibility of using these devices in the MRI environment, and show brain activation in a network of cortical (motor cortex, insula, cingulate, amygdala) and sub-cortical (putamen, thalamus, globus pallidus, cerebellum) regions. Concomitant relative deactivations were seen in the ventral striatum and orbitofrontal cortex. These results reveal the brain processes involved in (simulated) smoking for the first time, and validate a novel approach to the study of smoking, and addiction more generally.

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“…A forced choice, single staircase paradigm as described by Doty (2015) was used to establish the ODT. A custom made olfactometer, [design based on previously published papers (Lundström et al, 2010; Lowen et al, 2016)], was used to administer the odorant stimuli to both nostrils for 5 s. The concentration obtained at the ODT was then used in the conscious olfactory perception task.…”

Section: Methodsmentioning

confidence: 99%

Continuous Theta Burst Stimulation Over the Right Orbitofrontal Cortex Impairs Conscious Olfactory Perception

2019

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The right orbitofrontal cortex (rOFC) has been proposed as the region where conscious olfactory perception arises; however, evidence supporting this hypothesis has all been collected from neuroimaging and lesion studies in which only correlation and not a temporal pattern can be established. Continuous theta burst stimulation (cTBS) causes a reversible disruption of cortical activity and has been used successfully to disrupt orbitofrontal activity. To overcome intrinsic limitations of current experimental research, a crossover, double-blind, prospective and longitudinal study was carried out in which cTBS was applied over the rOFC to evaluate its effect on odorant stimuli detection. All subjects received real and sham cTBS. Experimental procedures were done in two different sessions with a separation of at least one week between them to avoid carryover and learning effects. A total of 15 subjects completed the experiment, and their data were included in the final analysis (10 women, 5 men, mean age 22.40 ± 3.41). Every session consisted of two different measures of the conscious olfactory perception task: A baseline measure and one 5 min after cTBS/sham. Compared to baseline, marks in the olfactory task during the sham cTBS session increased ( p = 0.010), while marks during the real cTBS session decreased ( p = 0.017). Our results support the hypothesis that rOFC is an important node of a complex network required for conscious olfactory perception to arise. However, the exact mechanism that explains our results is unclear and could be explained by the disruption of other cognitive functions related to the rOFC.

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Improved low-cost, MR-compatible olfactometer to deliver tobacco smoke odor

Cited by 8 publications

References 23 publications

Odor Canopy: A Method for Comfortable Odorant Delivery in MRI

Odor Canopy: A Method for Comfortable Odorant Delivery in MRI

Investigating the neural correlates of smoking: Feasibility and results of combining electronic cigarettes with fMRI

Continuous Theta Burst Stimulation Over the Right Orbitofrontal Cortex Impairs Conscious Olfactory Perception

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