Chemosensory Perception最新文献

Women’s olfactory perception varies across the menstrual cycle. The influence of oral contraceptives on this variability remains unclear.

To further estimate this, we assessed discrimination performance for both body odors and ordinary odorants in 36 women, 18 naturally ovulating, and 18 using oral contraceptives. Each participant was tested once a week over the course of a month, and data was then parsed into menstrual phases.

In naturally ovulating women, at the transition from follicular to luteal phases, there was a decline of 19% (p = 0.003) in olfactory discrimination of body odors but not ordinary odorants. In turn, in women using oral contraceptives, only at a later time of the month, at a point corresponding to the late luteal phase and shift from post-ovulation to pre-menstruation, was there a decline of 20% (p = 0.002) in olfactory discrimination performance. Moreover, when we reorganized the data from women using oral contraceptives in order to separately assess the contraceptive withdrawal period (the few days off pills), we observed a 23% reduction (p = 0.01) in discrimination accuracy of body odors but not ordinary odorants during this time alone.

Women have reduced ability to discriminate body odors during the withdrawal period of oral contraception.

If women indeed consider men’s body odor in their mate selections, then the oral contraception withdrawal period may not be the best time to make such decisions.

Prescription medication use may be associated with phantom odor perception. We evaluated associations between number of prescription medications and their therapeutic class and phantom odor perception among US adults.

Data were collected between 2011 and 2014 as part of the National Health and Nutrition Examination Survey (NHANES). A complex sampling design resulted in a nationally representative sample of 7417 adults aged 40 years and older. During an in-home interview, participants were asked whether they had experienced an unpleasant, bad, or burning odor when nothing is there. Prescription medication use was assessed using validation with prescription bottles, when possible.

Almost one quarter (23.3%) of adults uses ≥ 5 prescription medications. Use of five or more prescription medications is associated with 70% greater odds of phantom odor perception (OR 1.69 (1.09, 2.63)). Among adults 60 years and older, antidiabetic medications, antihyperlipidemic agents, and proton pump inhibitors are associated with 74–88% greater odds of report of phantom odor (OR = 1.74 (1.09, 2.77), OR = 1.85 (1.22. 2.80), and OR = 1.88 (1.15, 3.07)), respectively.

Phantom odor perception may be a side effect of antidiabetic or antihyperlipidemic agents. Among people taking proton pump inhibitors, phantom odors may also be a consequence of gastric gas reflux.

Common prescription medications may be providing an olfactory stimulus.

The main purpose of this study was to investigate the overall relation between the mean (at the nomothetic or group level) subjective valence and arousal ratings for odors. Although well established in other sensory modalities (e.g., visual, auditory, gustatory, tactile), this relation has not previously been investigated for odors covering a large range of the valence dimension. In addition, we evaluated the EmojiGrid (a recently introduced intuitive graphical affective self-report tool) for the affective appraisal of odors.

Young and healthy participants (N = 56, 32 females) used the EmojiGrid to rate the perceived valence and arousal for 40 different and randomly presented odors, ranging in valence from unpleasant to pleasant.

The overall relation between mean valence and arousal can be described by a U-shaped (quadratic) form; odors scoring near neutral on mean valence have the lowest mean arousal ratings, while odors scoring either high (pleasant) or low (unpleasant) on mean valence show higher mean arousal ratings. The results for odors that were also used in previous studies in the literature agree with their earlier reported values.

Mean arousal ratings increase with (positive or negative) emotional valence. Participants intuitively used the EmojiGrid to report their affective appraisal of odors without any verbal labels or written instructions.

The current findings are relevant for various applications and environments (e.g., public, retail, entertainment) where odors are used to induce desired emotional states (e.g., relaxation, arousal) and behaviors. The EmojiGrid can efficiently be applied to assess whether specific odors evoke the desired subjective affective experiences.

During sensory evaluations of minty products, white chocolate is proposed as a palate cleanser between sample tastings. However, this is not an evidence-based practice, as no literature proves this. The aim of this study was therefore to identify the best palate cleanser to use in sensory evaluation of minty confectionery products.

Three chewing gums with different cooling intensity were chewed for 3?min by a trained panel and evaluated for overall cooling, nose tingling, mouth burning, minty aroma, and sweetness. After the sample tasting, the following different palate cleansers were proposed: low-salt breadstick, whole milk, milk chocolate, white chocolate, and sunflower oil, compared with the resting time (control). The residual sensations were measured for the next 15?min.

Breadstick and seed oil are the most effective palate cleansers on overall cooling carry-over. White chocolate seems to be effective on mint aroma, but this is likely to be due to its strong flavour, masking other perceptions. Moreover, both white and milk chocolates affect negatively the sweetness perception, by increasing it soon after the consumption, and even impacting on the next sample evaluation.

None of the palate cleansers were able to fully re-establish the oral environment after 15?min. Therefore, further studies on combinations, or on repeated use of the same palate cleanser, are proposed.

The use of an effective palate cleanser can reduce the time for product testing and increase data precision. Finding a proper palate cleanser for minty products is a strategy to optimise sensory evaluations in confectionery industry.

The importance of an olfactory assessment of individuals with neurological diseases has attracted attention. Cerebrovascular disease is one of the most common diseases in Japan, but there are few reports on olfaction in patients with stroke. Herein we examined olfaction in patients with stroke.

We assessed 50 patients hospitalized for neurorehabilitation after stroke. For the assessment of olfaction, the dual tests known as the T&T olfactometry (T&T) test and the odor identification Open Essence (OE) test were administered. Since the OE test was introduced only recently in Japan, 100 healthy volunteers participated to provide OE data as the control group. We analyzed the patients’ T&T and OE data and the controls’ OE data, and we investigated the relationship between the olfaction data and the patients’ stroke-induced lesion areas.

None of the patients reported experiencing inconvenience due to olfactory loss, although we classified 45 (90%) patients as hyposmic or anosmic based on their identification thresholds on the T&T test as well as their significantly low OE scores compared to the control data. However, the patients’ perception thresholds on the T&T test were in the normal range. Brain computed tomography examination data revealed that odor identification was not impaired in about half of the 23 patients with a putamen-thalamus lesion. In addition, our correlation analysis of each odorant in the OE test indicated that six of the 12 odorants are sufficient for olfactory assessments.

The results of the dual olfactory tests revealed that patients with stroke showed impaired odor identification but intact odor perception. It is possible that the direct pathway from the piriform cortex to the orbitofrontal cortex is essential for odor identification.

Because of their normal odor perception, most patients with stroke are not aware of their impaired odor identification. A set of six of the 12 odorants used in the OE test is capable of representing the total OE score, and its use will save time for olfactory tests in clinical assessments.

Two recent brain morphological studies reported inconsistent results on the neuroanatomical correlates of taste intensity rating among healthy populations. The current study re-visited this issue with a large and more homogeneous sample size. It was hypothesized that the orbitofrontal cortex, the sole region commonly reported by the two studies together with olfactory studies, had its gray matter volume (GMV) correlated to taste intensity rating.

The open data from the Human Connectome Project (HCP, S1200 release dataset) was used. Data from 213 subjects were analyzed. They were aged 22–25, completed 3-Tesla structural brain scan, and were asked to taste a bitter solution (0.001 M quinine) and rate the perceived intensity with a general Labelled Magnitude Scale. The age-adjusted taste intensity rating was used for the current analysis. Voxel-based morphometry (VBM) using CAT12 toolbox implemented in SPM12 was conducted with the default procedures and settings. Whole brain analysis was performed at a threshold of cluster p < 0.05, familywise error corrected (FWE), with a primary cluster-forming threshold of uncorrected voxel p < 0.001.

Voxel-wise GMV was significantly correlated to taste intensity rating in the right angular gyrus. OFC was insignificant even with a more liberal threshold of uncorrected voxel p < 0.001.

The current results were again different from previously published reports. This might be due to heterogeneous population, data processing, and analytical methods.

At the current stage, the morphometric finding from brain imaging is not yet a simple and reliable biomarker for assessing taste intensity perception.

Olfaction has an important role in physiological and affective processes, as well as the potential to have profound effects on activities such as sleep and learning. We investigated two commercially manufactured odors (“Deep Sleep” and “Oriental,” from This Works) purported to promote sleep, compared with control odor, where we aimed to explore whether neural and behavioral differences existed after odor inhalation.

In a neuroimaging study, 30 healthy participants were exposed to the odors via an olfactometer during functional magnetic resonance imaging (fMRI). In a further behavioral study using 12 chronic insomniacs, we investigated whether the commercial odors showed effects on sleep during a double-blind, randomized home evaluation.

In the neuroimaging, the odors were related to activation of olfactory-relevant areas, such as the orbitofrontal cortex, and we found positive connectivity between the piriform cortex and the hippocampus, amygdala, insula, and middle cingulate cortex. Deep Sleep specifically activated the superior temporal gyrus, whereas Oriental activated the caudate. Further, these commercial odors showed some beneficial impact on sleep.

The perceptual and neural impacts of the commercial odors showed that olfactory stimulation can potentially aid sleep and modify affective processes in a number of ways.

The present work opens up opportunities for further investigations into how different odors may lead to specific behavioral and physiological modifications, such as their impact on sleep and well-being, which may provide non-pharmacological alternative approaches.

Brain activation in response to olfactory stimuli has been studied using functional magnetic resonance imaging (fMRI), but there is little knowledge about processing repeated olfactory information which is usual in daily life.

This fMRI study was designed to investigate brain response to repeated odorant stimulation with positive and negative valences in 12 healthy right-handed volunteers. There was a 25-min rest interval between two fMRI runs with identical stimulation paradigms with two odors, as phenylethyl alcohol (PEA) and isovaleric acid (IVA), and the two odors were released alternately.

There was a similar activation pattern in regions of primary and secondary olfactory cortex induced by odors of both valences, especially by negative odor. Weakened activation of the brain is responsive to repeated both pleasant and unpleasant smell. Nevertheless, the repeated unpleasant odor has a more intimate relationship with the piriform cortex, amygdala, and hippocampus.

We conclude that asymmetric brain activation in response to repeated odorant stimulation depended on valences and that the unpleasant odor can evoke more negative emotion and profound memory.

We explore the central processing about repeated olfactory information applied fMRI for the first time, revealing asymmetric brain activation in response to repeated odors of pleasantness and unpleasantness.

Humans are very sensitive to several bitter compounds, although there is great inter-individual variability in the elicited emotional (e.g., disgust) and somatic (e.g., nausea) responses. The variability might be associated with the personality trait “disgust proneness” (DP; general tendency to respond with the emotion of disgust).

This study examined the relationship between the sensitivity to quinine hydrochloride and DP in children (63 boys and 67 girls; mean age?=?8.5?years) and adults (107 men, 95 women; mean age?=?29.4?years). Each participant rated the perceived taste intensity of four gustatory stimuli (sucrose, 0.4?g/ml; sodium chloride, 0.25?g/ml; quinine hydrochloride, 0.006?g/ml; citric acid, 0.3?g/ml) and completed questionnaires that assessed the proneness to experience disgust, anxiety, and depressed mood.

The computed multiple linear regression analyses for the adults showed that DP but no other trait measure was associated with bitter sensitivity. In children, depression proneness and age were predictors of bitter sensitivity.

This study revealed age-dependent correlations between DP and bitter sensitivity.

This finding points to the dynamic features of taste sensitivity (and possibly DP) across the lifespan. Therefore, longitudinal studies are warranted.

Hyposmia and metacognitive errors are related to aging, depression, male gender, and cognitive decline. The current study investigated the awareness of olfactory dysfunction in subjective cognitive decline (SCD), mild cognitive impairment (MCI), and Alzheimer’s disease (AD), as well as the influence of additional factors.

A sample of 641 patients, including controls, SCD, non-amnestic MCI (naMCI), amnestic MCI (aMCI), and AD patients, was assessed with the Sniffin’ Sticks odor identification test (OIT) and the subjective olfactory capability (SOC) scale, in addition to measures of depressive symptoms, verbal memory, and executive functioning. Olfactory awareness groups were formed by means of the cutoffs of the OIT and the SOC.

Moderate and small, although significant, correlations between the OIT and the SOC were found among the study groups, with a significant discrimination of measured olfactory function via subjective assessment existing among controls but not among patients with AD. Of all AD patients, 34% overrated their sense of smell while 21% correctly identified themselves as being hyposmic, as opposed to corresponding 6% and 1% of healthy elderly. Overraters and correct hyposmic participants showed higher age and worse verbal memory and executive functions.

Reduced odor identification might underlie the same pathological changes within the brain as cognitive impairment and could serve as an additional marker for the development of AD.

Although people with AD are aware of hyposmia to some extent, the majority is affected by overestimation of the ability to smell, making the combination of subjective ratings and measures of olfactory function an interesting topic for further research.