We examined the role of TRPA1s in triggering the swallowing reflex. TRPA1s predominantly localized on thin nerve fibers and fibroblast-like cells in swallowing-related regions and on small to ...medium-sized superior laryngeal nerve-afferents in the nodose-petrosal-jugular ganglionic complex. Topical application of a TRPA1 agonist, allyl isothiocyanate (AITC), dose-dependently triggered swallowing reflexes. Prior topical application of a TRPA1 antagonist significantly attenuated the AITC-induced reflexes. Application of cold AITC (4 °C) very briefly reduced the on-site temperature to < 17 °C (temperature at which TRPA1s can be activated), but had no effect on triggering of the reflex. By contrast, reducing the on-site temperature to < 17 °C for a longer time by continuous flow of cold AITC or by application of iced AITC paradoxically delayed/prevented the triggering of AITC-induced reflexes. Prior application of the TRPA1 antagonist had no effect on the threshold for the punctate mechanical stimuli-induced reflex or the number of low-force or high-force continuous mechanical pressure stimuli-induced reflexes. TRPA1s are functional and act as chemosensors, but not as cold sensors or mechanosensors, for triggering of the swallowing reflex. A brief cold stimulus has no effect on triggering of the reflex. However, a longer cold stimulus delays/prevents triggering of the reflex because of cold anesthesia.
The widely known hue-heat effect, a multisensory phenomenon between vision and thermal sensing, is a hypothesis based on the idea that light and colors affect perceived temperature. However, the ...application of this effect has not been prevalent in our daily lives. To work towards developing more practical use of the hue-heat effect, we conducted a series of psychophysical experiments to investigate the relationship between perceived temperature and illumination in a well-controlled experimental environment. The results showed that illumination had three types of effects to change our sense of coolness/warmness: creating, eliminating, and exchanging effects. Furthermore, we confirmed the existence of two distinctive time courses for the three effects: creating effect started immediately, but the eliminating effect takes time. These findings provide us with a better understanding of the hue-heat effect and enable us to apply it in everyday life. Paired with the new technologies it can also help with energy conservation.
Introduction
We used dynamic causal modeling (DCM) to examine effective connectivity during cued autobiographical memory (AM) search in a left‐hemispheric network consisting of six major regions ...within the large network of brain regions recruited during memory retrieval processes.
Methods
Functional MRI data were acquired while participants were shown verbal cues describing common life events and requested to search for a personal memory associated with the cue. We examined directed couplings between the ventromedial (vmPFC), dorsomedial (dmPFC), and dorsolateral prefrontal cortices (dlPFC), hippocampus, angular gyrus, and the posterior midline cortex (RSC/PCC/Prec).
Results
During AM search, the vmPFC, dlPFC, and RSC/PCC/Prec acted as primary drivers of activity in the rest of the network. Moreover, when AM search completed successfully (Hits), the effective connectivity of the hippocampus on the vmPFC and angular gyrus was up‐modulated. Likewise, there was an increase in the influence of the RSC/PCC/Prec in the activity of the dlPFC and dmPFC. Further analysis indicated that the modulation observed during Hits is primarily a distributed phenomenon that relies on the interplay between different brain regions.
Conclusion
These results suggest that prefrontal and posterior midline cortical regions together with the dlPFC largely coordinate the processes underlying AM search, setting up the conditions on which the angular gyrus and the hippocampus may act upon when the outcome of the search is successful.
Autobiographical memory (AM) processes are known to recruit a large ensemble of brain regions. We used dynamic causal modeling to estimate effective connectivity among 6 of these regions based on fMRI data collected while participants performed an AM search task. Results were consistent with the notion that midline cortical regions are crucial in supporting the retrieval of AMs, and highlighted the interplay between the prefrontal and posterior midline regions during AM search.
Dental pain is a common health problem that negatively impacts the activities of daily living. Dentine hypersensitivity and pulpitis-associated pain are among the most common types of dental pain. ...Patients with these conditions feel pain upon exposure of the affected tooth to various external stimuli. However, the molecular mechanisms underlying dental pain, especially the transduction of external stimuli to electrical signals in the nerve, remain unclear. Numerous ion channels and receptors localized in the dental primary afferent neurons (DPAs) and odontoblasts have been implicated in the transduction of dental pain, and functional expression of various polymodal transient receptor potential (TRP) channels has been detected in DPAs and odontoblasts. External stimuli-induced dentinal tubular fluid movement can activate TRP channels on DPAs and odontoblasts. The odontoblasts can in turn activate the DPAs by paracrine signaling through ATP and glutamate release. In pulpitis, inflammatory mediators may sensitize the DPAs. They could also induce post-translational modifications of TRP channels, increase trafficking of these channels to nerve terminals, and increase the sensitivity of these channels to stimuli. Additionally, in caries-induced pulpitis, bacterial products can directly activate TRP channels on DPAs. In this review, we provide an overview of the TRP channels expressed in the various tooth structures, and we discuss their involvement in the development of dental pain.
Glossiness is the visual appearance of an object's surface as defined by its surface reflectance properties. Despite its ecological importance, little is known about the neural substrates underlying ...its perception. In this study, we performed the first human neuroimaging experiments that directly investigated where the processing of glossiness resides in the visual cortex. First, we investigated the cortical regions that were more activated by observing high glossiness compared with low glossiness, where the effects of simple luminance and luminance contrast were dissociated by controlling the illumination conditions (Experiment 1). As cortical regions that may be related to the processing of glossiness, V2, V3, hV4, VO-1, VO-2, collateral sulcus (CoS), LO-1, and V3A/B were identified, which also showed significant correlation with the perceived level of glossiness. This result is consistent with the recent monkey studies that identified selective neural response to glossiness in the ventral visual pathway, except for V3A/B in the dorsal visual pathway, whose involvement in the processing of glossiness could be specific to the human visual system. Second, we investigated the cortical regions that were modulated by selective attention to glossiness (Experiment 2). The visual areas that showed higher activation to attention to glossiness than that to either form or orientation were identified as right hV4, right VO-2, and right V3A/B, which were commonly identified in Experiment 1. The results indicate that these commonly identified visual areas in the human visual cortex may play important roles in glossiness perception.
•First fMRI experiments examining human neural correlates of glossiness perception•Stimulus-induced neural responses and attention-induced modulation were examined.•Ventral visual pathway involvement, including hV4 and VO-2, was suggested.•The involvement of ventral pathway is consistent with previous monkey studies.•Involvement of V3A/B in dorsal pathway also suggested, which may be human specific
The larynx and associated laryngopharyngeal regions are innervated by the superior laryngeal nerve (SLN) and are highly reflexogenic. Transient receptor potential (TRP) channels have recently been ...detected in SLN innervated regions; however, their involvement in the swallowing reflex has not been fully elucidated. Here, we explore the contribution of two TRP channels, TRPV1 and TRPM8, located in SLN-innervated regions to the swallowing reflex. Immunohistochemistry identified TRPV1 and TRPM8 on cell bodies of SLN afferents located in the nodose-petrosal-jugular ganglionic complex. The majority of TRPV1 and TRPM8 immunoreactivity was located on unmyelinated neurons. Topical application of different concentrations of TRPV1 and TRPM8 agonists modulated SLN activity. Application of the agonists evoked a significantly greater number of swallowing reflexes compared with the number evoked by distilled water. The interval between the reflexes evoked by the agonists was shorter than that produced by distilled water. Prior topical application of respective TRPV1 or TRPM8 antagonists significantly reduced the number of agonist-evoked reflexes. The findings suggest that the activation of TRPV1 and TRPM8 channels present in the swallowing-related regions can facilitate the evoking of swallowing reflex. Targeting the TRP channels could be a potential therapeutic strategy for the management of dysphagia.
Objective
Facial attractiveness has been reported to be influenced by visual features such as facial shape and the colour and texture of the skin. However, no empirical studies have examined the ...effects of facial skin radiance on facial attractiveness. The present study investigated whether types of skin reflection (i.e. radiant, oily and shiny, and matte) and the position of the reflection on the face influence facial attractiveness and other affective impressions.
Methods
A total of 160 female participants (1) estimated the ages and (2) evaluated attractiveness and other impressions of unfamiliar female faces in a total of seven skin reflection conditions. These conditions incorporated three types of reflection (i.e. radiant, oily and shiny, and matte) and three positions of the reflection on the face (i.e. entire facial skin, only cheeks, and only T‐zone).
Results
The facial images of radiance on entire faces were rated as appearing younger than the facial images of oily shine on entire faces and the matte faces. Attractiveness ratings and other positive impressions increased in the order of the matte (ranked lowest), the oily shine on entire face, and the radiance on entire face (ranked highest) conditions. The reflection position also influenced facial attractiveness: attractiveness ratings and other positive impressions were higher in the radiance on entire face condition than in the radiant cheeks and the radiant T‐zone conditions. Interestingly, the radiant cheek faces were rated more radiant and healthier but less feminine and less bright than the radiant T‐zone faces.
Conclusion
These results suggest that facial radiance enhances facial attractiveness and conveys a wide variety of positive impressions on the observer. The magnitude of the effects of cheek radiance and T‐zone radiance differs across various affective impressions. Nevertheless, the results demonstrate that cheek and the T‐zone radiance both contribute to higher attractiveness and other positive impressions of the radiance on entire faces. We believe that our findings can contribute as a guide to the enhancement of positive facial impressions by means of skin radiance, thereby leading to a better understanding of the value of skincare and base makeup.
Résumé
Objectif
Selon certaines études, l’attractivité du visage viendrait de caractéristiques visuelles telles que la forme du visage ainsi que la couleur et la texture de la peau. Cependant, aucune étude empirique n’a examiné les effets de l’éclat de la peau sur l’attractivité du visage. La présente étude s’est intéressée aux divers types de reflets de la peau (par exemple une peau lumineuse, une peau grasse et luisante ou une peau mate) et à leur position sur le visage, et a cherché à savoir s’ils influençaient l’attractivité du visage et d’autres impressions d’ordre affectif.
Méthodes
Au total, 160 participantes 1) ont estimé l’âge et 2) ont évalué l’attractivité et d’autres impressions de visages féminins inconnus sur sept types de reflets de la peau au total. Ces états comprenaient trois types de reflets (lumineux, gras et mat) et trois positions des reflets sur le visage (toute la peau du visage, joues uniquement et partie yeux‐nez « zone T » uniquement).
Résultats
Les photos de visages caractérisées par un éclat sur tout le visage ont été considérées comme étant plus jeunes que celles dont la peau était grasse‐luisante sur l’ensemble du visage et que les visages à peau mate. Les notes attribuées pour l’attractivité et les autres impressions positives augmentent dans l’ordre suivant : peau mate (note la plus basse), peau grasse‐luisante sur tout le visage et luminosité sur tout le visage (note la plus haute). La position du reflet a elle aussi joué un rôle sur les notes attribuées à l’attractivité des visages, et les autres impressions positives ont obtenu des scores plus élevés pour une luminosité de tout le visage que pour des joues lumineuses et une zone T lumineuse. Il est intéressant de noter que les visages aux joues lumineuses ont été jugés plus lumineux et plus sains, mais moins féminins et moins éclatants que les visages présentant une zone T lumineuse.
Conclusion
Ces résultats suggèrent que l’éclat du visage améliore l’attractivité du visage et communique toutes sortes d’impressions positives à l’observateur. L’ampleur des effets de l’éclat sur les joues et sur la zone T diffère selon les différentes impressions d’ordre affectif. Néanmoins, les résultats démontrent que la luminosité des joues et de la zone T contribue à rendre le visage plus séduisant ainsi qu’à d’autres impressions positives suscitées par la luminosité de l’ensemble du visage. Nous sommes convaincus que nos résultats peuvent servir à guider la façon de renforcer l’impression positive produite par un visage en faisant ressortir la luminosité de la peau, et amener ainsi à mieux comprendre la valeur des soins de la peau et des bases de maquillage.
Bats use echolocation through flexible active sensing via ultrasounds to identify environments suitable for their habitat and foraging. Mimicking the sensing strategies of bats for echolocation, this ...study examined how humans acquire new acoustic-sensing abilities, and proposes effective strategies for humans. A target geometry identification experiment-involving 15 sighted people without experience of echolocation-was conducted using two targets with different geometries, based on a new sensing system. Broadband frequency-modulated pulses with short inter-pulse intervals (16 ms) were used as a synthetic echolocation signal. Such pulses mimic buzz signals emitted by bats for echolocation prior to capturing their prey. The study participants emitted the signal from a loudspeaker by tapping on Android devices. Because the signal included high-frequency signals up to 41 kHz, the emitted signal and echoes from a stationary or rotating target were recorded using a 1/7-scaled miniature dummy head. Binaural sounds, whose pitch was down-converted, were presented through headphones. This way, time-varying echo information was made available as an acoustic cue for target geometry identification under a rotating condition, as opposed to a stationary one. In both trials, with (i.e., training trials) and without (i.e., test trials) answer feedback immediately after the participants answered, the participants identified the geometries under the rotating condition. Majority of the participants reported using time-varying patterns in terms of echo intensity, timbre, and/or pitch under the rotating condition. The results suggest that using time-varying patterns in echo intensity, timbre, and/or pitch enables humans to identify target geometries. However, performance significantly differed by condition (i.e., stationary vs. rotating) only in the test trials. This difference suggests that time-varying echo information is effective for identifying target geometry through human echolocation especially when echolocators are unable to obtain answer feedback during sensing.
We show that if A is a (not necessarily unital) separable, simple and non‐type I CM‐algebra, then for every properly infinite hyperfinite von Neumann algebra M with separable predual, its Ocneanu ...central sequence algebra M′∩Mω arises as a sub‐quotient of the central sequence algebra F(A) defined by the second‐named author. In particular, this answers affirmatively the question of Kirchberg ‘Central sequences in C∗‐algebras and strongly purely infinite algebras’, Operator algebras: the Abel Symposium 2004, Proceedings of the First Abel Symposium, Oslo, 3–5 September 2004 (eds O. Bratteli, S. Neshveyev and C. Skau; Springer, Berlin, Heidelberg, 2006), X, 279, 175–231: the central sequence C∗‐algebra of the reduced free group C∗‐algebra Cred∗(F2) is non‐commutative.
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