Smell Stimuli Research Articles

Advances in sensory science: From perception to consumer acceptance

Advances in sensory science: From perception to consumer acceptance

Odor-Induced Taste Enhancement Is Specific to Naturally Occurring Temporal Order and the Respiration Phase.

Interaction between odor and taste information creates flavor perception. There are many possible determinants of the interaction between odor and taste, one of which may be the somatic sensations associated with breathing. We assumed that a smell stimulus accompanied by inhaling or exhaling enhances taste intensity if the order is congruent with natural drinking. To present an olfactory stimulus from the identical location during inhalation and exhalation, we blocked the gap between the tube presenting the olfactory stimulus and the nostril. Participants breathed and ingested the solution according to the instructions on the screen and evaluated the solution's taste intensity. Vanilla odor enhanced the sweet taste in both retronasal and orthonasal conditions when the order of stimuli was congruent with natural drinking, but it did not do so in either condition when they were incongruent. The results suggest that breathing is a determinant of odor-taste interaction. The methods of presenting olfactory stimuli used in this study were compared and discussed in relation to those used in previous studies. Odor-induced taste enhancement depends on the time order of smell with breathing and taste congruency in natural drinking. Taste enhancement was induced by odor in both conditions by minimizing differences in odor presentation between them.

A bioinspired model to motivate learning of appetitive signals’ incentive value under a Pavlovian conditioning approach

Nowadays, the general artificial intelligence field aims to emulate some human behavior features in computational models for different objectives. This article proposes a model grounded in neurosciences focusing on individual behavior under appetitive circumstances. Environmental stimuli inspire human behavior because they represent a (learned) incentive value (IV) linked to the satisfaction of motivational states (MSs). That is, the expected behavior is goal-directed. We describe the generation of the incentive learning process. To reach this objective, we propose a computational-bioinspired model exemplifying the IV encoding process of a perceived smell stimulus for its setup, recovery and updating using Pavlovian conditioning. The proposed model highlights the main processes involved in Pavlovian incentive learning (PIL) and complementaries, e.g., an early integration between a smell stimulus and an MS, the generation of a temporal reward history, the prediction of a reward, the calculation of the obtained reward, the evaluation of reward error, among others. The model’s functionality was validated in two phases: the first stage was the acquisition of the IV and the second stage was a go/nogo task based on an incentive value and its MS.

Design of a Neurofeedback Training System for Meditation Based on EEG Technology

Meditation is a form of mental training that has therapeutic potential and cognitive benefits that may enhance attention, mental well-being, and neuroplasticity. However, the learning process is not easy because meditators do not receive immediate feedback that lets them know if they are correctly doing the activity. EEG Neurofeedback training is one of the techniques to train brain self-regulation and it has the potential to increase the effectiveness of meditation. However, the benefits greatly differ between subjects with a high percentage of inefficacy. In this work, an EEG Neurofeedback Training System is proposed based on user-centered design methodology to provide real-time performance feedback to meditators to increase levels of attention and relaxation through a visual, sound and smell stimuli interface. Levels of attention and relaxation of nine participants were measured with a mobile Neurosky EEG headset biosensor during meditation practice to analyze the incidence of each type of stimuli during activity. Visual stimuli feedback was able to increase attention levels of 78% of the participants by 11.8% compared to a meditation session without any stimuli. The sound stimuli feedback was able to increase the relaxation levels of 44.4% of the participants by 16% compared to a session without any stimuli. These results might bring new insights for the design of a neurofeedback system interface for meditation. Further research on neurofeedback training interfaces for meditators is suggested to validate these results with more participants.

Development and Evaluation of an Outdoor Multisensory AR System for Cultural Heritage

Enhancing tourist visits to cultural heritage sites by making use of mobile augmented reality has been a tendency in the last few years, presenting mainly audiovisual experiences. However, these explorations using only visuals and sounds, or narratives, do not allow users to be presented with, for example, a particular smell that can be important to feel engaged or to better understand the history of the site. This article pursues the goal of creating an experience that puts the user in a scene planned to evoke several stimuli with SensiMAR prototype - a Multisensory Augmented Reality system that aims to be used in cultural heritage outdoors. When using SensiMAR, the user will be involved with visual reconstructions, surrounded by the soundscape of ancient times, and is exposed to a particular smell very common that time. Given the novelty of this proposal, ascertaining the usability of such a system was raised as a foremost demand. Thus, in addition to its development and implementation specifications, an experimental study was conducted to evaluate the usability of the system in end-users' perspective. The results obtained from random visitors of an archaeological site were analysed according to their sex, age, previous experience with augmented reality technology, and provided condition - audiovisual condition, and multisensory condition, with visual, audio, and smell stimuli. Results were collected from a total of 67 participants and show that this multisensory prototype achieved good usability results across all groups. No statistically differences were found, demonstrating good usability of the SensiMAR system regardless of their sex, age, previous experience with the technology or provided condition.

Tainted: An olfaction-enhanced game narrative for smelling virtual ghosts

Abstract This paper presents “Tainted”, a first-person 3D adventure game that enables players to experience a traditional horror folklore using visual-auditory-olfactory interactions. The system consists of a computer to play the game and a smell-emitting module that contains four different scents (jasmine, pineapple, mango and banana). The information provided by the additional olfactory stimuli delivers an immersive gaming experience by providing game narrative and signaling predefined game conditions (e.g. imminent threat, game hints). At the same time, smell stimuli attempt to invoke emotional responses such as fear and curiosity. Experiments were carried out to 1) validate the design of the device and 2) measure user enjoyment and experience with and without the added smell feedback using an adapted questionnaire from the GameFlow model. The results show that the provided olfactory stimuli are more informative to users and provoked greater emotions, as compared to the use of visual and auditory cues alone. The majority of participants preferred to have the added feedback device in the game (95% neutral and positive). However, approximately 26% of participants also noted that the smells are not distinct from each other. Nevertheless, it is suggested that the olfactory information is closely coupled with players’ experience and enjoyment of the narrative, as well as the smell-driven gameplay. Future studies of these factors will enable us to establish a framework to support multisensory game developers in the design of olfaction-enhanced games and other multimedia applications.

Fungiform Papilla Number and Olfactory Threshold Assessment in Males With and Without Barth Syndrome

Introduction Barth syndrome is a rare X-linked genetic disorder caused by a mutation or deletion of the tafazzin gene. Approximately 50–70% of affected males have family-reported feeding issues that affect eating habits and/or restrict dietary intake. Research to date suggests that these feeding problems may be related to differences in responsivity to taste and smell stimuli. The purpose of this study was to use indices of chemosensory function to study differences in food-related sensation and anatomy in males with and without Barth syndrome.

Latent constructs underlying sensory subtypes in children with autism: A preliminary study.

Recent reports identify sensory subtypes in ASD based on shared patterns of responses to daily sensory stimuli [Ausderau et al., 2014; Lane, Molloy, & Bishop, 2014]. Lane et al. propose that two broad sensory dimensions, sensory reactivity and multisensory integration, best explain the differences between subtypes, however this has yet to be tested. The present study tests this hypothesis by examining the latent constructs underlying Lane's sensory subtypes. Participants for this study were caregivers of children with autism spectrum disorder (ASD) aged 2-12 years. Caregiver responses on the Short Sensory Profile (SSP), used to establish Lane's sensory subtypes, were extracted from two existing datasets (total n = 287). Independent component analyses were conducted to test the fit and interpretability of a two-construct structure underlying the SSP, and therefore, the sensory subtypes. The first construct was largely comprised of the taste/smell sensitivity domain, which describes hyper-reactivity to taste and smell stimuli. The second construct had a significant contribution from the low energy/weak domain, which describes behaviors that may be indicative of difficulties with multisensory integration. Findings provide initial support for our hypothesis that sensory reactivity and multisensory integration underlie Lane's sensory subtypes in ASD. Autism Res 2017, 10: 1364-1371. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.

Light and smell stimulus protocol reduced negative frontal EEG asymmetry and improved mood

AbstractLight and smell have both been shown to induce beneficial changes to human psychophysiology. Bright light therapy has been shown to have a positive impact on anxiety and depression and smell has also been shown to have positive effects on mood, stress, anxiety and depression. We developed a method for the delivery of integrated light and smell stimulation to try to optimise positive psychophysiological benefit. We tested its effectiveness on a physiological measure, EEG frontal alpha asymmetry (FA) and a psychological paradigm, the POMS test, both of which have been used as a measure of emotional state and mood. Light, pleasant smell, combined light+smell and a no stimulus control were delivered for 90s while the frontal alpha asymmetry (FA) was monitored. Smell and light+smell caused significant reductions in negative FA during stimulation. Exposure to a longer 15 min nonadaptive light+smell stimulus protocol reduced negative FA and decreased negative affect (POMS). The effects were greater in the negative FA group. Both the physiological (EEG) and psychometric (POMS) data indicate that integrated light and smell stimulation can reduce negative affect and reduce a marker for anxiety/ depression. This light+smell sensory stimulation protocol could offer a safe treatment for depression/anxiety.

Combined non-adaptive light and smell stimuli lowered blood pressure, reduced heart rate and reduced negative affect

Bright light therapy has been shown to have a positive impact on seasonal affective disorder (SAD), depression and anxiety. Smell has also has been shown to have effects on mood, stress, anxiety and depression. The objective of this study was to investigate the effect of the combination of light and smell in a non-adaptive cycle. Human subjects were given smell (lemon, lavender or peppermint) and light stimuli in a triangular wave (60scycle) for 15min. Blood pressure and heart rate were monitored before and after each session for 5 consecutive days and a Profile of Mood States (POMS) test was administered before and after the sensory stimulation on days 1, 3 and 5.The light-smell stimulus lowered blood pressure, both systolic and diastolic, and reduced heart rate for all odours compared to control. Of the two sensory stimuli, the odour stimulus contributed most to this effect. The different aromas in the light-smell combinations could be distinguished by their different effects on the mood factors with lemon inducing the greatest mood changes in Dejection-Depression, Anger-Hostility, Tension-Anxiety.In conclusion, combined light and smell stimulation was effective in lowering blood pressure, reducing heart rate and improving mood. The combination was more effective than either smell or light stimuli alone, suggesting that a light-smell combination would be a more robust and efficacious alternative treatment for depression, anxiety and stress.

Facial Expression in Response to Smell and Taste Stimuli in Small and Appropriate for Gestational Age Newborns.

Small for gestational age newborns can later suffer from eating difficulties and slow growth. Nutritional preferences can be influenced by changes in sensory perception of smell and taste. To determine whether these could be detected at birth, the authors examined the different recognition pattern of smell and taste in small for gestational age newborns compared to appropriate for gestational age controls, as expressed by gusto-facial and naso-facial reflexes. The authors performed video analysis of facial expressions of 10 small for gestational age and 12 control newborns exposed to various tastes and smells. No difference in the facial recognition patterns for taste or smell was demonstrated between small for gestational age and controls, except for perception of distilled water. Newborns show recognizable patterns of facial expression in response to taste and smell stimuli. Perception of taste and smell in small for gestational age newborns is not different from controls, as measured by the method of facial recognition.

Mapping a Multi-sensory Identity Territory at the Early Design Stage

This article presents a kansei design methodology. It is placed at the very beginning of the design process and aims to influence the following steps in order to improve the user's understanding and experiencing of the designed product. The experimentation combines in a subtle way the design thinking approach of learning by doing and the kansei engineering quantitative approach. The research presented is based on the results of a previous study that defined the semantic and emotional scope of future hybrid cars for European using visual stimuli. This kansei design methodology creates and assesses multi-sensory atmospheres is order to provide tangible direction composed of vision, touch, hearing and smell stimuli. From the cognitive and affective responses of the 42 participants we were able to detail 3 directions for future cars interiors that aim to enrich the styling design briefs and to influence the design strategies such as the management of the different grades. The research presented here was supported by the Kansei Design department from Toyota Motor Europe (TME-KD). This collaboration also brought an industrial context to it.

Genetic Analysis of Chemosensory Traits in Human Twins

We explored genetic influences on the perception of taste and smell stimuli. Adult twins rated the chemosensory aspects of water, sucrose, sodium chloride, citric acid, ethanol, quinine hydrochloride, phenylthiocarbamide (PTC), potassium chloride, calcium chloride, cinnamon, androstenone, Galaxolide™, cilantro, and basil. For most traits, individual differences were stable over time and some traits were heritable (h(2) from 0.41 to 0.71). Subjects were genotyped for 44 single nucleotide polymorphisms within and near genes related to taste and smell. The results of these association analyses confirmed previous genotype-phenotype results for PTC, quinine, and androstenone. New associations were detected for ratings of basil and a bitter taste receptor gene, TAS2R60, and between cilantro and variants in three genes (TRPA1, GNAT3, and TAS2R50). The flavor of ethanol was related to variation within an olfactory receptor gene (OR7D4) and a gene encoding a subunit of the epithelial sodium channel (SCNN1D). Our study demonstrates that person-to-person differences in the taste and smell perception of simple foods and drinks are partially accounted for by genetic variation within chemosensory pathways.

The role of taste and oral somatosensation in olfactory localization

Although there is only one set of olfactory receptors, odours are experienced as smells when sniffing things (e.g., sniffing a wine's bouquet) and as flavours when the olfactory stimulus is present in the mouth (e.g., drinking wine). How this location binding--external versus internal environment--is achieved is poorly understood. Experiment 1 employed a new procedure to study localization, which was then used to explore whether localization is primarily dependent upon simultaneous oral somatosensation. Experiment 2, using solutions of varying viscosity, and Experiment 3, using oral movement of varying vigour, revealed that sniffed odours are not localized to the mouth by somatosensation alone. Instead, Experiment 4 demonstrated that a tastant needs to be present and that increasing tastant concentration generates increasing oral localization. Experiment 5 found that this reliance upon gustation reflects the previously observed "confusion" that people show for taste and smell stimuli in the mouth. We suggest that this "confusion" reflects the gustatory system's superior ability to suppress olfactory attention, thus assisting flavour binding.

Influência do estresse alimentar na digestibilidade em cães

O objetivo deste trabalho foi avaliar a influência do estresse alimentar sobre a digestibilidade aparente de uma dieta comercial em cães. Foram utilizados 12 animais, sem raça definida, divididos em dois grupos de seis, submetidos a: tratamento 1 (T1) - caracterizado por indução do estresse alimentar pela irregularidade do horário de alimentação e provocação por estímulos visuais, olfatórios e auditivos, e tratamento 2 (T2) - caracterizado por regularidade do horário de alimentação e ausência de provocação (grupo-controle). As fezes para o ensaio de digestibilidade foram colhidas na primeira e na quarta semana após o início dos estímulos. Não foram encontradas diferenças entre tratamentos (grupos) e entre períodos quanto aos coeficientes de digestibilidade aparente da matéria seca, proteína bruta, extrato etéreo, extrato não nitrogenado, fibra detergente neutra e energia bruta.

Objektiver Riechtest mit kognitiven Potenzialen

An objective smelling test is indicated for a reliable assessment of olfactory disorders. Usually olfactory evoked potentials (OEP) are registered. But the technique of this measurement is complicated and the generation of the OEP depends on the respiration of the subject. Alternatively, the contingent negative variation (CNV) can be used in the diagnosis of anosmia and parosmia, requiring only a simple olfactory stimulator. OEP and CNV were derived from 25 adults with normal smelling and from 16 patients with anosmia after head injury. First, the "direct" CNV was registered when the subjects expected a tone following a smell stimulus after 1.5 s. Using two different odors in a random order, the tone only followed one of them, so the "selective" CNV was scored. In both tests a distinct CNV was found in 21 and 23 normal smelling subjects, respectively. OEPs were absent in 4.3 % of this control group. No patient with anosmia showed an OEP or a CNV. The amplitudes of the "selective" CNV are significantly higher than those of the "direct" CNV. No gender dependency was found. The results show that an objective olfactometry can be realized by registration of CNV. Contrary to the measurement of OEP which depend on the physical parameters of olfactory stimuli, CNV correlates well with the cognitive identification of odor.

Monitoring responses in the human orbito-frontalcortex to smell stimuli, by the use of multi-channel multi-wavelength diffuse NIR spectroscopy

Monitoring responses in the human orbito-frontalcortex to smell stimuli, by the use of multi-channel multi-wavelength diffuse NIR spectroscopy

昆虫の化学応答研究法―５ 昆虫・ダニ由来の匂い刺激に対するきゅう覚応答

昆虫の化学応答研究法―５ 昆虫・ダニ由来の匂い刺激に対するきゅう覚応答

Taste and smell perception in aging.

The taste and smell experience of other human beings cannot be known directly. Thus our understanding of age‐related changes in the perception of taste and smell is derived inferentially. Inferences based on verbal reports and on the performance of tasks involving taste and smell stimuli suggest that some older individuals are impaired. The perceptual disadvantage of older adults appears to be more marked or more easily measured for complex than for simple stimuli. Some difference between older and younger adults may not be primarily sensory; others may arise from differences only incidentally associated with aging. The study of taste and smell perception in aging continues to challenge the psychophysical investigator to define the nature and extent of age‐related change and to demonstrate its underlying mechanisms.

Rapid, permanent, loss of memory for absolute intensity of taste and smell

Memory formation for the absolute intensity of taste and smell was investigated in a series of experiments. In Experiment 1, 336 subjects tasted 10 ml of 15% sucrose and were asked to remember the strength of the solution. They were retested with 5%, 10%, 15%, or 20% sucrose, at one of four delay intervals (1, 5, or 15 min, or 72 h). They compared the second stimulus with the first stimulus and reported whether the second was “less sweet, ” “the same, ” or “sweeter. ” Subjects reliably reported that 5% sucrose was less sweet and that 20% sucrose was sweeter. However, when the second stimulus was 15% sucrose (i.e., was equal to the standard), approximately 60% of the subjects reported that it was sweeter, regardless of the delay interval between the two stimuli. About 2/3 of those tasting 10% sucrose reported that it was as sweet as or sweeter than the 15% standard. A similar finding from a procedure using magnitude estimation was reported in Experiment 2. The same pattern of results was also found for an olfactory memory test (Experiment 3). When asked to match either a 1.33- or a 5.0-ppm pyridine olfactory stimulus, subjects consistently picked a concentration weaker than the standard. Apparently, olfactory and taste stimuli are remembered as being substantially weaker as soon as the memory for these stimuli can be tested. A memory model that posits a sensory store within which a taste or smell stimulus of a given intensity rapidly fades to a lower level of intensity is suggested. The new memory is then relatively unchanged for at least 3 days.