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Sensors (Basel, Switzerland) Nov 2017The implementation of neuromorphic methods has delivered promising results for vision and auditory sensors. These methods focus on mimicking the neuro-biological... (Review)
Review
The implementation of neuromorphic methods has delivered promising results for vision and auditory sensors. These methods focus on mimicking the neuro-biological architecture to generate and process spike-based information with minimal power consumption. With increasing interest in developing low-power and robust chemical sensors, the application of neuromorphic engineering concepts for electronic noses has provided an impetus for research focusing on improving these instruments. While conventional e-noses apply computationally expensive and power-consuming data-processing strategies, neuromorphic olfactory sensors implement the biological olfaction principles found in humans and insects to simplify the handling of multivariate sensory data by generating and processing spike-based information. Over the last decade, research on neuromorphic olfaction has established the capability of these sensors to tackle problems that plague the current e-nose implementations such as drift, response time, portability, power consumption and size. This article brings together the key contributions in neuromorphic olfaction and identifies future research directions to develop near-real-time olfactory sensors that can be implemented for a range of applications such as biosecurity and environmental monitoring. Furthermore, we aim to expose the computational parallels between neuromorphic olfaction and gustation for future research focusing on the correlation of these senses.
Topics: Electronic Nose; Humans; Neurons; Smell; Vision, Ocular
PubMed: 29125586
DOI: 10.3390/s17112591 -
Neuron Aug 2006The basic psychophysical principle of speed-accuracy tradeoff (SAT) has been used to understand key aspects of neuronal information processing in vision and audition,... (Comparative Study)
Comparative Study
The basic psychophysical principle of speed-accuracy tradeoff (SAT) has been used to understand key aspects of neuronal information processing in vision and audition, but the principle of SAT is still debated in olfaction. In this study we present the direct observation of SAT in olfaction. We developed a behavioral paradigm for mice in which both the duration of odorant sampling and the difficulty of the odor discrimination task were controlled by the experimenter. We observed that the accuracy of odor discrimination increases with the duration of imposed odorant sampling, and that the rate of this increase is slower for harder tasks. We also present a unifying picture of two previous, seemingly disparate experiments on timing of odorant sampling in odor discrimination tasks. The presence of SAT in olfaction provides strong evidence for temporal integration in olfaction and puts a constraint on models of olfactory processing.
Topics: Animals; Discrimination Learning; Male; Mice; Mice, Inbred C57BL; Psychomotor Performance; Reaction Time; Smell; Stimulation, Chemical
PubMed: 16880129
DOI: 10.1016/j.neuron.2006.07.013 -
Environmental Health Perspectives Jun 2019
Topics: Air Pollutants; Air Pollution; Humans; Mexico; Odorants; Olfaction Disorders; Olfactory Perception; Smell; Urban Population
PubMed: 31190551
DOI: 10.1289/EHP3621 -
The Laryngoscope Aug 2022Previous work has shown the chemosensory dysfunction item of the 22-item Sinonasal Outcome Test (SNOT-22) that assesses problems with "taste/smell" has poor psychometric...
OBJECTIVE
Previous work has shown the chemosensory dysfunction item of the 22-item Sinonasal Outcome Test (SNOT-22) that assesses problems with "taste/smell" has poor psychometric performance compared with other items on the SNOT-22, which we have hypothesized is due to the simultaneous assessment of two different senses. Our aim was to determine whether distinct smell and taste items in the SNOT-22 would improve psychometric performance.
METHODS
One hundred and eighty-one CRS patients were recruited and completed the SNOT-22. Additional items querying problems with the senses of "smell" and "taste," using the same response scale and recall period were given to study participants. Item response theory (IRT) was used to determine IRT parameters, including item discrimination, difficulty, and information provided by each SNOT-22 item.
RESULTS
Confirming previous studies, the chemosensory item of the SNOT-22 (reflecting "taste/smell") had poor psychometric performance. Use of a distinct smell or taste item instead of the combined "taste/smell" item did not improve psychometric performance. However, a dedicated smell question resulted in a left shift of threshold parameters, showing that the dedicated smell item better captures moderate CRS disease burden than the original taste/smell item of the SNOT-22, which by virtue of near-identical IRT parameters appears to more greatly reflect problems with taste.
CONCLUSIONS
A dedicated smell- or taste-specific item, rather than the combined "taste/smell" item currently in the SNOT-22 does not provide significantly greater psychometric performance. However, a dedicated smell item may better capture moderate CRS disease burden compared with the current chemosensory item on the SNOT-22. Laryngoscope, 132:1644-1651, 2022.
Topics: Chronic Disease; Humans; Psychometrics; Quality of Life; Rhinitis; Sino-Nasal Outcome Test; Sinusitis; Smell; Taste
PubMed: 35353381
DOI: 10.1002/lary.30120 -
Current Biology : CB May 2021For many organisms, certain odorants trigger instinctive responses that are essential for survival. A new study shows that mixing odorants interferes with this innate...
For many organisms, certain odorants trigger instinctive responses that are essential for survival. A new study shows that mixing odorants interferes with this innate valence, demonstrating that innate odor information does not follow a privileged path through the brain.
Topics: Brain; Masks; Odorants; Smell
PubMed: 33974870
DOI: 10.1016/j.cub.2021.03.018 -
Annual Review of Psychology Jan 2024Historically, the human sense of smell has been regarded as the odd stepchild of the senses, especially compared to the sensory bravado of seeing, touching, and hearing.... (Review)
Review
Historically, the human sense of smell has been regarded as the odd stepchild of the senses, especially compared to the sensory bravado of seeing, touching, and hearing. The idea that the human olfaction has little to contribute to our experience of the world is commonplace, though with the emergence of COVID-19 there has rather been a sea change in this understanding. An ever increasing body of work has convincingly highlighted the keen capabilities of the human nose and the sophistication of the human olfactory system. Here, we provide a concise overview of the neuroscience of human olfaction spanning the last 10-15 years, with focus on the peripheral and central mechanisms that underlie how odor information is processed, packaged, parceled, predicted, and perturbed to serve odor-guided behaviors. We conclude by offering some guideposts for harnessing the next decade of olfactory research in all its shapes and forms.
Topics: Humans; Smell
PubMed: 37788573
DOI: 10.1146/annurev-psych-042023-101155 -
European Archives of... Jan 2022The olfactory system can be successfully rehabilitated with regular, intermittent stimulation during multiple daily exposures to selected sets of odors, i.e., olfactory... (Randomized Controlled Trial)
Randomized Controlled Trial
PURPOSE
The olfactory system can be successfully rehabilitated with regular, intermittent stimulation during multiple daily exposures to selected sets of odors, i.e., olfactory training (OT). OT has been repeatedly shown to be an effective tool of olfactory performance enhancement. Recent advancements in studies on OT suggest that its beneficial effects exceed olfaction and extend to specific cognitive tasks. So far, studies on OT provided compelling evidence for its effectiveness, but there is still a need to search for an optimal OT protocol. The present study examined whether increased frequency of OT leads to better outcomes in both olfactory and cognitive domains.
METHOD
Fifty-five subjects (28 females; M = 58.2 ± 11.3 years; 26 patients with impaired olfaction) were randomly assigned to a standard (twice a day) or intense (four times a day) OT. Olfactory and cognitive measurements were taken before and after OT.
RESULTS
OT performed twice a day was more effective in supporting olfactory rehabilitation and interventions targeted to verbal semantic fluency than OT performed four times a day, even more so in subjects with lower baseline scores.
CONCLUSIONS
OT is effective in supporting olfactory rehabilitation and interventions targeted to verbal semantic fluency. However, it may be prone to a ceiling effect, being efficient in subjects presenting with lower baseline olfactory performance and lower verbal semantic fluency.
Topics: Aged; Cognition; Female; Humans; Middle Aged; Odorants; Olfaction Disorders; Smell
PubMed: 33864109
DOI: 10.1007/s00405-021-06810-9 -
Hormones and Behavior Feb 2015This article is part of a Special Issue "Chemosignals and Reproduction". Chemical cues were probably the first cues ever used to communicate and are still ubiquitous... (Review)
Review
This article is part of a Special Issue "Chemosignals and Reproduction". Chemical cues were probably the first cues ever used to communicate and are still ubiquitous among living organisms. Birds have long been considered an exception: it was believed that birds were anosmic and relied on their acute visual and acoustic capabilities. Birds are however excellent smellers and use odors in various contexts including food searching, orientation, and also breeding. Successful reproduction in most vertebrates involves the exchange of complex social signals between partners. The first evidence for a role of olfaction in reproductive contexts in birds only dates back to the seventies, when ducks were shown to require a functional sense of smell to express normal sexual behaviors. Nowadays, even if the interest for olfaction in birds has largely increased, the role that bodily odors play in reproduction still remains largely understudied. The few available studies suggest that olfaction is involved in many reproductive stages. Odors have been shown to influence the choice and synchronization of partners, the choice of nest-building material or the care for the eggs and offspring. How this chemical information is translated at the physiological level mostly remains to be described, although available evidence suggests that, as in mammals, key reproductive brain areas like the medial preoptic nucleus are activated by relevant olfactory signals. Olfaction in birds receives increasing attention and novel findings are continuously published, but many exciting discoveries are still ahead of us, and could make birds one of the animal classes with the largest panel of developed senses ever described.
Topics: Animals; Birds; Pheromones; Sexual Behavior, Animal; Smell
PubMed: 24928570
DOI: 10.1016/j.yhbeh.2014.06.001 -
Current Biology : CB Apr 2023Odor perception is first determined by how the myriad of environmental volatiles are detected at the periphery of the olfactory system. The combinatorial activation of...
Odor perception is first determined by how the myriad of environmental volatiles are detected at the periphery of the olfactory system. The combinatorial activation of dedicated odorant receptors generates enough encoding power for the discrimination of tens of thousands of odorants. Recent studies have revealed that odorant receptors undergo widespread inhibitory modulation of their activity when presented with mixtures of odorants, a property likely required to maintain discrimination and ensure sparsity of the code for complex mixtures. Here, we establish the role of human OR5AN1 in the detection of musks and identify distinct odorants capable of enhancing its activity in binary mixtures. Chemical and pharmacological characterization indicate that specific α-β unsaturated aliphatic aldehydes act as positive allosteric modulators. Sensory experiments show decreased odor detection threshold in humans, suggesting that allosteric modulation of odorant receptors is perceptually relevant and likely adds another layer of complexity to how odors are encoded in the peripheral olfactory system.
Topics: Humans; Receptors, Odorant; Smell; Odorants; Olfactory Receptor Neurons; Olfactory Perception
PubMed: 36977419
DOI: 10.1016/j.cub.2023.03.016 -
ELife May 2019A combination of genetic, anatomical and physiological techniques has revealed that the lateral horn, a region of the brain involved in olfaction in flies, has many more...
A combination of genetic, anatomical and physiological techniques has revealed that the lateral horn, a region of the brain involved in olfaction in flies, has many more types of neurons than expected.
Topics: Animals; Drosophila melanogaster; Models, Biological; Neurons; Olfactory Pathways; Smell
PubMed: 31112128
DOI: 10.7554/eLife.47720