Chemosensory Perception最新文献

Experts acquire superior abilities in their specific domains by training. Sommelier students, who are future olfaction experts, could be an excellent model to study the effects of olfactory training.

We tested whether sommelier students display superior olfactory abilities early in their education: within the first 2?months of education, we examined the olfactory function, i.e., discrimination and identification of odors as well as olfactory threshold and olfactory memory, of n?=?25 sommelier students and compared them to n?=?29 control students. We also tested episodic and working memory.

We found that sommelier students outperformed controls in free and cued identification, but we did not observe any difference in discrimination or threshold tasks. There was also no difference in memory tasks.

Early in their education, sommelier students appear to be better at identifying odors, but do not display other superior olfactory abilities.

Results suggest that sommeliers are better at identifying odors than the average person, either because they enter into training with superior identifications skills or are able to learn to identify odors at a very fast rate.

Correlations between olfactory performance and particular personality traits (e.g., disgust proneness), as well as symptoms of specific mental disorders (e.g., depression) have been found in numerous studies with adults. The present questionnaire study examined whether similar associations already exist in childhood.

The olfactory discrimination ability of 66 children (32 boys and 34 girls aged between 7 and 11?years) was tested. In addition, the children filled out screening questionnaires to assess the severity of symptoms related to depression, various anxiety disorders (e.g., panic disorder, social anxiety disorder), and disgust proneness. A multiple regression analysis was calculated with olfactory performance as criterion variable and questionnaire scores as predictor variables.

The results showed that depression and disgust proneness were negatively associated with olfactory discrimination ability. Moreover, high levels of social anxiety and low levels of panic symptoms were found to be positive predictors of olfactory performance.

This investigation identified specific associations between olfactory performance and affective symptoms in children.

Future tests with pediatric samples (children with anxiety disorders, depression) are recommended.

Olfactory habituation results from prolonged exposure to an odor, leading to perceptual changes defined by several characteristics. To date, human habituation research has focused on orthonasal olfaction which is perceived externally while ignoring internal routes of odor perception related to flavor. In our study, we conducted two experiments to characterize retronasal olfactory habituation and measured its impact on flavor perception.

In Experiment 1, participants were presented a food odor and non-food odor retronasally, using an orally adhered strip. Each participant rated the odor intensity using a time-intensity procedure. After exposure, the participants ate a lime-flavored gummy and rated the lime flavor. In experiment 2, the same procedure was performed for a low-level lime odor, a simple (lime oil) and complex (lime oil + sucrose + citric acid) beverage as the flavor stimuli.

Our results demonstrated two known principles of habituation for retronasally presented odors: (1) prolonged exposure leads to decreased perception and (2) weaker stimuli lead to more rapid habituation. Additionally, we found that the non-food odor habituated slower than the food odor; however, the participants seemed to recover simultaneously upon food and beverage consumption leading to no change in flavor perception.

The findings of this study give evidence that we habituate to different odors at different rates; more specifically, we provide evidence that differentiates between odor origin and concentration.

This is the first time-intensity characterization of retronasal odor habituation. Additionally, a novel method of administering retronasal odors is presented.

In daily life, people encounter a wide range of odors, most of which contain multiple chemical substances. So-called bimodal odors stimulate both the olfactory and trigeminal nerve, and the interaction between these two systems shapes the perception of the odor. However, temporal encoding of these sensory systems during bimodal odor processing has received limited scientific attention.

To investigate this, we recorded the electrophysiological response in 17 participants to relatively unimodal olfactory (strawberry), trigeminal (l-isopulegol) and strongly bimodal (strawberry and l-isopulegol) stimuli.

ERP amplitudes and intensity ratings were significantly bigger for bimodal stimulation, as compared to unimodal stimulations. No significant difference was observed between N1 and P2 response latencies to olfactory and bimodal stimuli while responses to both stimuli showed longer latencies compared to the response of the trigeminal stimulus.

Results provide further evidence of interaction between olfactory and trigeminal systems; additional activation of the olfactory system results in more vigorous electrophysiological responses and the experience of higher intensity. In addition, results indicate that the trigeminal system is faster to react to stimulation.

The current study offers a view on the temporal processing of bimodal odorants that are most likely to be encountered in the environment. We link the more vigorous electrophysiological response to a more complex odorant with activation of different neural structures.

The flavor of Szechuan pepper plays an important role in Sichuan cuisine, where it is responsible for the tingling and numbing characteristic. The aims of this study were to characterize and identify aroma-active compounds of Szechuan pepper and to evaluate changes in flavor components between room and high temperature (ca. 70–80?°C).

Solvent-assisted flavor evaporation (SAFE) and headspace solid-phase microextraction (HS-SPME) followed by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-olfactometry (GC-O) were used.

In this study, linalool, linalyl acetate, and limonene were identified as the major components by both SAFE and HS-SPME. Seven compounds, namely myrcene, limonene, 1,8-cineole, linalool, 2-phenylethanol, 4-methylacetophenone, and trans-carveol, were identified as aroma-active compounds using GC-O. The most intense aroma-active compounds were 1,8-cineole and linalool. Moreover, 2-phenylethanol and 4-methylacetophenone were identified as aroma-active components for the first time in Szechuan pepper. The relative contents of 1,8-cineole, linalool, 2-phenylethanol, 4-methylacetophenone, and trans-carveol were significantly increased as simulated cooking temperature increased from 40 to 75?°C, whereas myrcene, limonene, and hexanal were significantly decreased; 1,8-cineole was not detected at 40?°C but was detected at 75?°C.

A total of 83 volatile compounds were identified, including 62 by SAFE and 57 by HS-SPME. Of these, 34 volatile compounds were identified by both SAFE and HS-SPME. For the first time, 2-phenylethanol and 4-methylacetophenone were identified as key aroma-active components in Szechuan pepper. The overall flavor of Szechuan pepper might be influenced by a result of the relative ratios of key aroma-active components. Cooking temperature should be taken into consideration when Szechuan pepper is used as an ingredient in food.

These results could be beneficial for furthering our understanding of aroma-active compounds in Szechuan pepper and improving dishes prepared with this ingredient.

Olfactory dysfunction is an early marker of neurological disease and a common symptom in psychotic disorders. Previous anatomical and functional research suggests that sex effects may be crucial in the assessment of the olfactory system. Nonetheless, the neural mechanisms through which the factor sex impacts olfactory perception are still not well understood. In this context, we use fMRI to investigate sex differences in the passive processing of chemical stimuli, in order to obtain new neuroscientific data that may help improve the assessment of odor perception.

Thirty healthy subjects (17 women) were stimulated with mint and butanol (event-related design) in a 3.0-T MRI scanner. A one-sample t test analysis was performed in order to observe olfactory-related activations. Intergroup differences (women vs. men) and the influence of each aroma were analyzed using a 2?×?2 ANOVA and post hoc contrasts.

Men and women showed differential activity (males?>?females) in right superior/middle temporal areas, the right inferior frontal cortex, and the hypothalamus. Both groups showed a predominance of the right hemisphere for the processing of odors.

Functional differences between women and men in olfaction are not restricted to specific sensory areas and reflect a more general sex-dependent effect in multisensory integration processes.

Considering sex differences is essential in order to develop more specific and efficient strategies for the assessment and rehabilitation of the olfactory system and for the interpretation of the olfactory loss as an early biomarker of neurological and psychiatric diseases.

Many people seem to be looking for similar attributes when searching for a potential romantic partner. Olfactory social cues can be important parts of the process, though there are individual differences as to their value. Gay men, for example, value scent less in selecting a romantic partner than do heterosexual men (White and Cunningham, Chemosens Percept 10:31–41, 2017). Is it possible that the relative importance of olfaction in mate selection is simply a natural consequence of being generally aware of odorants?

The present study examined the relationship between odor awareness and odor importance in mating in two studies. Participants in each of the studies completed both the Romantic Interests Survey (Herz and Inzlich, Evol Hum Behav 23:359–364, 2002) and the Odor Awareness Survey (Smeets et al., Chem Senses 33:725–734, 2008). In the first study, 455 college-aged heterosexual individuals were surveyed, while in the second study, 453 individuals varying in sexual preference (142 heterosexual women, 161 heterosexual men, and 150 gay men) completed the questionnaires.

Principle components analyses from both studies revealed two different components underlying scores on the RIS; one component best accounted for OAS scores. Regression analysis for both studies indicated that OAS scores predicted the first RIS principle component, but not the second one.

The value of odorants in selecting a romantic partner seems to reflect two different underlying attitudes. The first attitude values all aspects of the smell of a lover, while the second only finds it important that the lover does not smell badly. Odor awareness is related only to the first of these attitudes.

These findings suggest that odor awareness accounts for some of the attitudes concerning the value of odors in mate selection, but not all of them. Other factors, such as the need to avoid aversive stimuli, may also contribute to the relative importance of olfaction in selecting a partner.

Odor perception is biased by verbal–semantic processes when cues on an odor’s source are readily available from the context. At the same time, olfaction has been characterized as basically sensation driven when this information is absent. In the present study, we examined whether language effects occur when verbal cues are absent and how expectations about an odor’s identity shape odor evaluations.

A total of 56 subjects were asked to rate 20 unlabeled odor samples on perceptual dimensions as well as quality attributes and to eventually provide an odor source name. In a subsequent session, they performed the same rating tasks on a set of written odor labels that was compiled individually for each participant. It included both the 20 correct odor names (true labels) and in any case of incorrect odor naming in the first session, the self–generated labels (identified labels).

We compared odor ratings to ratings of both types of labels to test whether differences between odor and odor label evaluations were rooted in identification mechanisms. In cases of false identifications, we found higher consistencies between the evaluation of an odor and its identified label than between the description of an odor and its true (yet not associated) label.

These results indicate that odor evaluations are strongly affected by the mental image of an odor rather than the actual sensory codes and that this mental image is built spontaneously. Our findings imply that odors and odor labels are evaluated similarly for identical objects and that the differences found in similar studies may have been rooted in different mental representations being evaluated.

Odor sensations provoke odor naming without explicit demand. These self–generated hypotheses about an odor’s source exert a considerable semantic impact on odor perceptual processing, regardless of their accuracy.

Studies of changes in taste threshold, perceived intensity, liking, and preference during pregnancy were reviewed, because such changes have the potential to negatively impact nutrient intake in pregnant women.

Medline and Web of Science were searched; eligibility was based on inclusion, exclusion, and quality criteria.

Fourteen articles were included: 5 reported taste thresholds, 8 taste intensity, and 13 liking/preferences. Articles addressed sweet, salty, sour, and bitter, not umami. Results of self-reported changes suggested that many women experienced some sort of alteration in taste during pregnancy. Studies with real stimuli demonstrated that the only consistent finding for taste thresholds was that pregnant women showed higher thresholds for bitterness in their first trimester. For taste intensity, no consistent differences between pregnant women and controls were observed. However, over the course of pregnancy, salty intensity seemed to decrease, the intensity of other tastes did not change. During pregnancy, higher saltiness was liked more and salty snacks were consumed more, particularly in the second and/or third trimester. Drinks with lower sweetness were preferred and intake of sweet snacks was highest in the second trimester. Preference for sour and bitter did not seem to be affected.

Self-reports suggested that many women experienced some taste changes during pregnancy, while changes based on studies with real stimuli were limited.

Many women experienced a higher threshold for bitter perception in the first trimester, a preference for sweet snacks in the second trimester, and higher saltiness appetite in the second and third trimester of pregnancy, which may have nutritional consequences.