3,036 research outputs found

    A new wine tasting approach based on emotional responses to rapidly recognize classic european wine styles

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    Conventional tasting sheets are widely used to evaluate wine quality in wine tasting competitions. However, the higher scores are mostly obtained by international commercial wines, resulting in lower scores being awarded to the classic Europeanwines. We hypothesize that this is due to the tasting methodology that fails to recognize this wine style. Therefore, the purpose of this work was to show the implementation of a new wine tasting approach to overcome this drawback. The proposed training technique is based on the emotional responses of the taster after smelling two wines of clearly opposite styles. The first wine is characterized by high aromatic intensity but low in-mouth intensity, perceived as disappointing to the taster, here defined as an “easy” wine. The second wine is characterized as a wine with low aromatic intensity but that provides an unexpectedly positive in-mouth experience, here defined as a “difficult” wine. These emotions are explained by the wine sensorial characteristics. The “easy” wine has an intense, simple smell with short persistence while the “difficult” wine has a low intensity, complex aroma, and long persistence. The first style corresponds to the international commercial wines most prized in international wine challenges. The second, frequently rejected by untrained tasters, is consistent with the “so called” classic European wines, and is characterized by light red or yellow straw colors, weak smell intensity, and aggressive mouth-feel. After no more than four training sessions and using the OIV tasting sheet, inexperienced tasters were able to score “difficult” wines equally as “easy” wines and understand their different attributes. In conclusion, this new tasting approach may be used by wine professionals to explain the characteristics of high quality wines that are not easily recognized by untrained consumersinfo:eu-repo/semantics/publishedVersio

    Short-term memory of temporal aspects of noxious and innocuous thermal sensation : psychophysical and fMRI studies

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    La douleur peut ĂȘtre considĂ©rĂ©e comme un systĂšme de protection qui signale une menace et qui nous avertit des dĂ©gĂąts imminents aux tissus. En tant que mĂ©canisme de dĂ©fense, il nĂ©cessite l'apprentissage et la mĂ©moire des expĂ©riences du passĂ© pour la survie et les comportements liĂ©s Ă  la douleur. Par consĂ©quent, notre expĂ©rience de la douleur actuelle est fortement influencĂ©e par les expĂ©riences antĂ©rieures et l'apprentissage. Cependant, malgrĂ© son importance, notre comprĂ©hension actuelle de l'interaction entre le systĂšme de la douleur et le systĂšme de mĂ©moire est trĂšs limitĂ©e. La mĂ©moire de la douleur est un sujet de recherche trĂšs vaste. Il nĂ©cessite une comprĂ©hension des mĂ©canismes impliquĂ©s Ă  chaque Ă©tape du systĂšme de mĂ©moire (mĂ©moire immĂ©diate, Ă  court terme et Ă  long terme) et l'interaction entre eux. Parmi les Ă©tapes multiples de la mĂ©moire, la mĂ©moire Ă  court terme de la douleur est une zone qui est moins recherchĂ©e, alors qu'il existe une Ă©norme quantitĂ© de recherche neuroscientifique dans la mĂ©moire Ă  court terme sur d'autres modalitĂ©s, en particulier la vision. L'Ă©tude de la mĂ©moire Ă  court terme de la douleur est particuliĂšrement importante car cette trace de la mĂ©moire Ă  court terme de la douleur est ensuite convertie en mĂ©moire Ă  long terme et affecte ensuite les expĂ©riences futures de la douleur. Cette thĂšse est largement axĂ©e sur la mĂ©moire Ă  court terme de la douleur. La complexitĂ© et la multi dimensionnalitĂ© de la douleur ajoutent encore un autre Ă©lĂ©ment Ă  la recherche sur la mĂ©moire de la douleur. Par exemple, la trace de la mĂ©moire de la douleur peut contenir des traces de mĂ©moire de diverses composantes de la douleur telles que la rĂ©ponse sensorielle affective, cognitive et motrice et l'interaction entre elles. Par consĂ©quent, une premiĂšre Ă©tape dans l'exploration neuroscientifique de la mĂ©moire de la douleur nĂ©cessite la rĂ©duction de l'expĂ©rience de la douleur tout en englobant tous ces diffĂ©rents composants Ă  un seul composant. Dans la recherche prĂ©sentĂ©e ici, nous avons gĂ©nĂ©ralement examinĂ© cela par des instructions d'attention ‘ top-down’ pour assister Ă  la dimension sensorielle de la douleur. La recherche prĂ©cĂ©dente sur la mĂ©moire Ă  court terme de la douleur a Ă©galement portĂ© principalement sur la dimension sensorielle de la douleur. Cependant, parmi les dimensions sensorielles de la douleur, la mĂ©moire Ă  court terme de l'intensitĂ© et de la dimension spatiale de la douleur a fait l'objet de recherches antĂ©rieures. MalgrĂ© son importance, la dimension temporelle de la douleur est restĂ©e complĂštement inexplorĂ©e dans la recherche sur la mĂ©moire de la douleur. La recherche menĂ©e dans cette thĂšse est consacrĂ©e Ă  l'exploration de la mĂ©moire Ă  court terme de la durĂ©e de la douleur. La durĂ©e de la douleur peut ĂȘtre suivie de maniĂšre indĂ©pendante, mais peut Ă©galement ĂȘtre suivie conjointement avec la dimension d'intensitĂ© telle que le suivi dynamique de l'intensitĂ© de la douleur dans le temps. Les Ă©tudes menĂ©es dans cette thĂšse traitent spĂ©cifiquement du traitement isolĂ© de la durĂ©e de la douleur ainsi que du traitement conjoint de la dimension durĂ©e / intensitĂ© de la douleur. La premiĂšre Ă©tude psychophysique a explorĂ© la nature de la reprĂ©sentation mentale du modĂšle de mĂ©moire de la douleur thermique dynamique et a Ă©galement Ă©tĂ© conçue pour aborder les diffĂ©rences de la dimension sensorielle et affective de la douleur thermique dans la mĂ©moire Ă  court terme. La deuxiĂšme Ă©tude psychophysique portait sur les propriĂ©tĂ©s de la mĂ©moire Ă  court terme de la sensation thermique non douloureux en comparant le suivi dynamique de la sensation et le suivi isolĂ© de la durĂ©e d'un Ă©vĂ©nement thermique non douloureux. La troisiĂšme Ă©tude poursuit l'exploration du traitement dynamique de la durĂ©e conjointement avec l'intensitĂ© par rapport au traitement isolĂ© de la durĂ©e dans la mĂ©moire Ă  court terme en utilisant des stimuli thermiques douloureuse une rĂ©sonance magnĂ©tique fonctionnelle (IRMF). Dans l'ensemble, les rĂ©sultats des Ă©tudes psychophysiques ont montrĂ© une transformation significative de la durĂ©e et de la dynamique de la sensation thermique douloureux et non-douloureux dans la mĂ©moire Ă  court terme; comme la perte d'informations somatosensorielles temporelles en mĂ©moire. Nous avons en outre montrĂ© une amĂ©lioration du rappel de la durĂ©e dans le suivi dynamique de la durĂ©e, en comparaison avec le suivi de la durĂ©e isolĂ©e. Nous avons Ă©galement montrĂ© des diffĂ©rences dans les corrĂ©lats neuronaux de la mĂ©moire Ă  court terme de la durĂ©e de douleur par rapport Ă  la dynamique de douleur. L'Ă©tude de l'IRMF a montrĂ© des similitudes frappantes dans les corrĂ©lats neuronaux sous-jacents Ă  la mĂ©moire Ă  court terme de douleur et d'autres modalitĂ©s telles que la contribution des coticĂ©s fronto-pariĂ©tales ainsi que les corticaux sensoriels impliquĂ©s dans le traitement perceptuel.Pain can be viewed as a protective system that signals threat and alerts us to impending tissue damage. As a defense mechanism, it necessitates the learning and memory of past painful experiences for survival and pain-related behavior. Therefore our current pain experience is heavily influenced by previous experiences and learning. However, despite its importance, our current understanding of the interaction between the pain system and the memory system is very limited. Pain memory is a very broad topic of research on its own. It requires an understanding of the mechanisms involved at each stage of the memory system (immediate, short-term, and long-term memory), and the interaction among them. Among the multiple stages of memory, the short-term memory of pain is an area that is less researched, while there are enormous amount of neuroscientific research in short-term memory of other modalities, particularly vision. Investigation of the short-term memory of pain is especially important as the short-term memory trace of pain is converted to long-term memory and subsequently affects future pain experiences. This thesis is broadly focused on the short-term memory of pain. The complexity and multi-dimensionality of pain adds yet another element to the research on pain memory. For example, the memory trace of pain may contain memory traces of various components of pain such as sensory, affective, cognitive, and motoric responses, and the interactions among them. Therefore, an initial step in the neuroscientific exploration of pain memory requires narrowing down the pain experience, which encompasses all of these various components, to one single component. In the research presented here, we achieved this using top-down attentional instructions to attend to the sensory component of pain. The previous research on short-term memory of pain also focused mainly on the sensory component of pain. However, within the sensory component of pain the short-term memory of intensity and spatial dimension of pain has been the focus of previous research. Despite its importance, the temporal dimension of pain remained completely unexplored in pain memory research. Thus, the research conducted in this thesis is devoted to the exploration of short-term memory of the duration of pain. Pain duration can be tracked independently, but it can also be tracked conjointly with intensity, such as in dynamic tracking of pain intensity over time. The studies addressed in this thesis examined the isolated processing of pain duration as well as conjoint processing of the duration and intensity of pain. The first psychophysical study explored the nature of the mental representation of the memory template of dynamic thermal pain sensation and, additionally, addressed the differences between the sensory versus affective dimensions of thermal pain sensation in short-term memory. The second psychophysical study focused on properties of the short-term memory of innocuous thermal sensation by comparing dynamic tracking of sensation versus isolated tracking of duration of an innocuous thermal event. The third study explored the dynamic processing of duration conjointly with intensity, versus the isolated processing of duration in short-term memory, using noxious thermal stimuli and functional magnetic resonance imaging (fMRI). Overall, the results of the psychophysical studies showed significant transformation of duration and dynamics information of noxious and innocuous thermal sensation in short-term memory, such as loss of temporal somatosensory information. Additionally, we showed improvement in duration recall during dynamic tracking versus isolated tracking of duration. The fMRI study revealed differences in neural correlates of short-term memory of pain duration versus pain dynamics. Importantly, it also showed striking similarities between neural correlates underlying the short-term memory of pain and those underlying other modalities, such as a contribution of fronto-parietal cortices as well as sensory cortices involved in perceptual processing

    Congenital deafness is associated with specific somatosensory deficits in adolescents

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    Hearing and touch represent two distinct sensory systems that both rely on the transformation of mechanical force into electrical signals. Here we used a battery of quantitative sensory tests to probe touch, thermal and pain sensitivity in a young control population (14-20 years old) compared to age-matched individuals with congenital hearing loss. Sensory testing was performed on the dominant hand of 111 individuals with normal hearing and 36 with congenital hearing loss. Subjects with congenital deafness were characterized by significantly higher vibration detection thresholds at 10 Hz (2-fold increase, P < 0.001) and 125 Hz (P < 0.05) compared to controls. These sensory changes were not accompanied by any major change in measures of pain perception. We also observed a highly significant reduction (30% compared to controls p < 0.001) in the ability of hearing impaired individual's ability to detect cooling which was not accompanied by changes in warm detection. At least 60% of children with non-syndromic hearing loss showed very significant loss of vibration detection ability (at 10 Hz) compared to age-matched controls. We thus propose that many pathogenic mutations that cause childhood onset deafness may also play a role in the development or functional maintenance of somatic mechanoreceptors

    Complex interaction of sensory and motor signs and symptoms in chronic CRPS.

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    Spontaneous pain, hyperalgesia as well as sensory abnormalities, autonomic, trophic, and motor disturbances are key features of Complex Regional Pain Syndrome (CRPS). This study was conceived to comprehensively characterize the interaction of these symptoms in 118 patients with chronic upper limb CRPS (duration of disease: 43±23 months). Disease-related stress, depression, and the degree of accompanying motor disability were likewise assessed. Stress and depression were measured by Posttraumatic Stress Symptoms Score and Center for Epidemiological Studies Depression Test. Motor disability of the affected hand was determined by Sequential Occupational Dexterity Assessment and Michigan Hand Questionnaire. Sensory changes were assessed by Quantitative Sensory Testing according to the standards of the German Research Network on Neuropathic Pain. Almost two-thirds of all patients exhibited spontaneous pain at rest. Hand force as well as hand motor function were found to be substantially impaired. Results of Quantitative Sensory Testing revealed a distinct pattern of generalized bilateral sensory loss and hyperalgesia, most prominently to blunt pressure. Patients reported substantial motor complaints confirmed by the objective motor disability testings. Interestingly, patients displayed clinically relevant levels of stress and depression. We conclude that chronic CRPS is characterized by a combination of ongoing pain, pain-related disability, stress and depression, potentially triggered by peripheral nerve/tissue damage and ensuing sensory loss. In order to consolidate the different dimensions of disturbances in chronic CRPS, we developed a model based on interaction analysis suggesting a complex hierarchical interaction of peripheral (injury/sensory loss) and central factors (pain/disability/stress/depression) predicting motor dysfunction and hyperalgesia

    Tactile Modulation of the Sensory and Cortical Responses Elicited by Focal Cooling in Humans and Mice

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    Distinct sensory receptors transduce thermal and mechanical energies, but we have unified, coherent thermotactile experiences of the objects we touch. These experiences must emerge from the interaction of thermal and tactile signals within the nervous system. How do thermal and mechanical signals modify each other as they interact along the pathway from skin to conscious experience? In this thesis, we study how mechanical touch modulates cooling responses by combining psychophysics in humans and neural recordings in rodents. For this, we developed a novel stimulator to deliver focal, temperature-controlled cooling without touch. First, we used this method to study in humans the sensitivity to focal cooling with and without touch. We found that touch reduces the sensitivity to near-threshold cooling, which is perhaps analogous to the well-established ‘gating’ of pain by touch. Second, we studied the perceived intensity of cooling with and without touch. We found that tactile input enhances the perceived intensity of cooling. Third, we measured the responses of the mouse primary somatosensory cortex to cooling and mechanical stimuli using imaging and electrophysiological methods. We found multisensory stimuli elicited non-linear cortical responses at both the population and cellular level. Altogether, in this thesis, we show perceptual and cortical responses to non-tactile cooling for the first time. Based on our observations, we propose a new model to explain the interactions between cooling and mechanical signals in the nervous system. This thesis advances our understanding of how touch modulates cold sensations during thermotactile stimulation

    Neurophysiology of skin thermal sensations

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    Undoubtedly, adjusting our thermoregulatory behavior represents the most effective mechanism to maintain thermal homeostasis and ensure survival in the diverse thermal environments that we face on this planet. Remarkably, our thermal behavior is entirely dependent on the ability to detect variations in our internal (i.e., body) and external environment, via sensing changes in skin temperature and wetness. In the past 30 years, we have seen a significant expansion of our understanding of the molecular, neuroanatomical, and neurophysiological mechanisms that allow humans to sense temperature and humidity. The discovery of temperature-activated ion channels which gate the generation of action potentials in thermosensitive neurons, along with the characterization of the spino-thalamo-cortical thermosensory pathway, and the development of neural models for the perception of skin wetness, are only some of the recent advances which have provided incredible insights on how biophysical changes in skin temperature and wetness are transduced into those neural signals which constitute the physiological substrate of skin thermal and wetness sensations. Understanding how afferent thermal inputs are integrated and how these contribute to behavioral and autonomic thermoregulatory responses under normal brain function is critical to determine how these mechanisms are disrupted in those neurological conditions, which see the concurrent presence of afferent thermosensory abnormalities and efferent thermoregulatory dysfunctions. Furthermore, advancing the knowledge on skin thermal and wetness sensations is crucial to support the development of neuroprosthetics. In light of the aforementioned text, this review will focus on the peripheral and central neurophysiological mechanisms underpinning skin thermal and wetness sensations in humans

    Supraspinal nocifensive responses of cats: Spinal cord pathways, monoamines, and modulation

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    These experiments were conducted to determine (1) whether dorsal and ventral ascending spinal pathways can each mediate unlearned supraspinal nocifensive responses of cats to noxious thermal stimuli and (2) whether interrupting the spinal projection of supraspinal monoaminergic neurons alters the excitability and natural modulation of these responses. In partially restrained cats, thermal pulses (≄ 47°C) delivered to the hindlimbs of intact cats or rostral to lesions of the thoracic spinal cord elicited abrupt body movements and interruption of eating (or of exploring for) liquified food. These electronically monitored responses automatically terminated the stimulus. Natural modulation of responsiveness was produced by delivering food and thermal stimuli simultaneously; this reduced response probability by an average of 41%. Complete transection of the thoracic spinal cord eliminated both thermally elicited responses, and orienting responses to noxious and tactile mechanical stimulation of the hindlimbs. Ventral bilateral thoracic spinal cord lesions that spared only the dorsal funiculus and portions of the dorsolateral funiculus (three cats) significantly reduced orienting responses to all mechanical hindlimb stimuli and reduced, but did not eliminate, movement and interrupt responses to noxious thermal hindlimb stimuli. Response latency was unaffected. Food-induced response supression persisted although lumbar spinal cord concentrations of serotonin (5HT) and norepinephrine (NE) were markedly reduced. A bilateral lesion of the dorsal funiculi and dorsal portions of the dorsolateral funiculi (one cat) also reduced nocifensive responsiveness, but only the NE concentration in lumbar spinal cord was reduced significantly relative to a matched cervical sample. In contrast, deep bilateral lesions of the dorsolateral funiculi (two cats) produced an increase in the probability of movement and interrupt responses without affecting either response latency or food-induced response supression. Lumbar spinal cord concentrations of NE and, in one cat, 5HT were reduced. We conclude that (1) the dorsal and ventral spinal funiculi are each sufficient to initiate and necessary to maintain normal supraspinally organized nocifensive behavior in the cat; (2) descending monoaminergic pathways are not necessary for the phasic modulation of these responses; and (3) the tonic excitability, but not the phasic modulation, of these responses is determined in part by fibers in the dorsolateral funiculus.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50039/1/902700412_ftp.pd

    Thermal and tactile interactions in the perception of local skin wetness at rest and during exercise in thermo-neutral and warm environments

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    The central integration of thermal (i.e. cold) and mechanical (i.e. pressure) sensory afferents is suggested as to underpin the perception of skin wetness. However, the role of temperature and mechanical inputs, and their interaction, is still unclear. Also, it is unknown whether this intra-sensory interaction changes according to the activity performed or the environmental conditions. Hence, we investigated the role of peripheral cold afferents, and their interaction with tactile afferents, in the perception of local skin wetness during rest and exercise in thermo-neutral and warm environments. Six cold-dry stimuli, characterised by decreasing temperatures [i.e. -4, -8 and -15°C below the local skin temperature (Tsk)] and by different mechanical pressures [i.e. low pressure (LP): 7 kPa; high pressure (HP): 10 kPa], were applied on the back of 8 female participants (age 21 ± 1 years), while they were resting or cycling in 22 or 33°C ambient temperature. Mean and local Tsk, thermal and wetness perceptions were recorded during the tests. Cold-dry stimuli produced drops in Tsk with cooling rates in a range of 0.06 to 0.4°C/s. Colder stimuli resulted in increasing coldness and in stimuli being significantly more often perceived as wet, particularly when producing skin cooling rates of 0.18°C/s and 0.35°C/s. However, when stimuli were applied with HP, local wetness perceptions were significantly attenuated. Wetter perceptions were recorded during exercise in the warm environment. We conclude that thermal inputs from peripheral cutaneous afferents are critical in characterizing the perception of local skin wetness. However, the role of these inputs might be modulated by an intra-sensory interaction with the tactile afferents. These findings indicate that human sensory integration is remarkably multimodal
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