Search results for "olfaction"

Behavioral and physiological bases of relaxing and stimulating effects of odors and music

2021

This doctoral thesis examines the psychological and physiological mechanisms as well as the factors involved in the relaxing and stimulating effect (emotional activation) of pleasant odors, building on research work from the music domain. In Studies 1a and 1b, we observed that the modulation of the activation induced by odors influenced temporal information processing by speeding-up or slowing-down the rate of the internal clock pacemaker, similarly to what was previously reported using musicalstimuli. Moreover, prior verbalsuggestion attributing incongruent activation properties to the odors eliminated these effects, highlighting the importance of a priori expectancies on olfactory-induced…

Behaviour and neural responses in crucian carp to skin odours from cross-order species

2012

Many teleost species respond with fright reactions to olfactory cues from injured skin of conspecifics, but they may also display responses to skin extracts of heterospecific fish. In the present study, we exposed crucian carp to skin extracts of conspecifics and three cross-order species of fish (brown trout, pike, and perch). Behavioural experiments showed that conspecific skin extracts induced fright reactions in crucian carp; extracts of brown trout induced such behaviour less frequently, while extracts of perch and pike were poor inducers of fright responses. The olfactory bulb is chemo-topically organized, and different sub-sets of neurons respond to functionally related odorants that…

The Power of Odor Persuasion: The Incorporation of Olfactory Cues in Virtual Environments for Personalized Relaxation

2021

Olfaction is the most ancient sense and is directly connected with emotional areas in the brain. It gives rise to perception linked to emotion both in everyday life and in memory-recall activities. Despite its emotional primacy in perception and its role in sampling the real physical world, olfaction is rarely used in clinical psychological settings because it relies on stimuli that are difficult to deliver. However, recent developments in virtual-reality tools are creating novel possibilities for the engagement of the sense of smell in this field. In this article, we present the relevant features of olfaction for relaxation purposes and then discuss possible future applications of involvi…

Differential influence of two acanthocephalan parasites on the antipredator behaviour of their common intermediate host

2007

7 pages; International audience; Fish acanthocephalans can modify the antipredator behaviour of their intermediate hosts in response to cues from fish predators. However, it is still unclear whether such behavioural changes are adaptive, or are just the consequence of infection. We addressed this question through studying two acanthocephalans, Pomphorhynchus laevis and Polymorphus minutus, and their intermediate host, the amphipod Gammarus pulex. Pomphorhynchus laevis completes its cycle in a freshwater fish, whereas P. minutus exploits waterbirds as final hosts.We first assessed vulnerability of infected and uninfected gammarids to predation by bullheads, Cottus gobio. Pomphorhynchus laevi…

Olfaction in the fetal and premature infant: functional status and clinical implications.

2004

This article considers olfaction as a functioning source of information for the fetus and the neonate, born on term or prematurely. It aims to present how odors are involved in the sensory continuity between the prenatal and postnatal environments and how they influence the earliest adaptive responses of newborns in the realms of self-regulation, emotional balance, feeding, and social interactions.Finally, it evaluates odors as sensory means to ameliorate the physiologic and behavioral responses of preterm infants to the adverse impacts of separation from mother, nonoral feeding, or iatrogenic distress.

Attitudes toward everyday odors for children with visual impairments: A pilot study

2010

The question of how the processing of stimuli from the external world is organized or reorganized when a sensory modality is altered or missing has been the subject of numerous studies, although the studies have mostly been on tactile and auditory abilities (Hatwell, 2003). In contrast, olfaction has been poorly investigated in people who are visually impaired, despite the increasing evidence that humans have a keen sense of smell (Schaal & Porter, 1991). Odors influence mood; well-being (Ehrlichman & Bastone, 1992); and social interactions, such as the choice of partners (Herz & Inzlicht, 2002). Emotional and social implications of odors go back to the earliest periods of development (Scha…

Caractérisation des enzymes du métabolisme des xénobiotiques olfactives chez le rat : régulation et rôle dans la détection périphérique des molécules…

2010

 Diplôme : Dr. d'Université; Les enzymes du métabolisme des xénobiotiques (EMX) jouent un rôle central dans la biotransformation et l’élimination de composés étrangers à l’organisme. Organisées en réseau de biotransformation, ces enzymes catalysent des réactions variées (oxydations, conjugaisons …) afin de rendre ces composés plus hydrophiles. Les EMX sont fortement exprimées dans l’épithélium olfactif de mammifères et des études in vitro ont montré qu’elles possèdent des activités élevées. Outre un rôle dans le métabolisme de molécules toxiques, ces enzymes pourraient être impliquées dans la modulation périphérique de l'olfaction. Les EMX pourraient contribuer à maintenir la sensibilité du…

Nxnl2 splicing results in dual functions in neuronal cell survival and maintenance of cell integrity

2012

International audience; The rod-derived cone viability factors, RdCVF and RdCVF2, have potential therapeutical interests for the treatment of inherited photoreceptor degenerations. In the mouse lacking Nxnl2, the gene encoding RdCVF2, the progressive decline of the visual performance of the cones in parallel with their degeneration, arises due to the loss of trophic support from RdCVF2. In contrary, the progressive loss of rod visual function of the Nxnl2-/- mouse results from a decrease in outer segment length, mediated by a cell autonomous mechanism involving the putative thioredoxin protein RdCVF2L, the second spliced product of the Nxnl2 gene. This novel signaling mechanism extends to o…

Semiochemical exploitation by two egg parasitoids,Trissolcus basalis and Trissolcus brochymenae (Hymenoptera: Scelionidae)

Chemo-orientation in egg parasitoids, a self-controlled movement in time and space, is led by volatile or substrate-borne chemicals distribution in the environment for purposes of locating host, food, mates and other resources. The perception of these chemical stimuli can be either from a distance by exploiting long-range infochemicals in the case of volatile chemoreception and/or upon contact with the cues when wasps are relatively close to the host in the case of contact chemo-reception by perceiving short-range infochemicals. In the present thesis, two different examples of chemo-orientation were treated. The first is an olfactory chemo-reception concerning Trissolcus basalis (Wollaston)…

Human awareness and uses of odor cues in everyday life: Results from a questionnaire study in children

2008

The Children's Olfactory Behavior in Everyday Life questionnaire was developed to assess attention to, and uses of, odors in real-life situations, and to evaluate individual variations. The tool comprises 16 items prompting self-reports of active seeking, awareness and affective reactivity to odors of food, people and the environment. Children (102 girls, 113 boys) aged 6–10 years participated in the study. The results revealed that girls were significantly more olfaction-oriented than boys, especially towards the odors of people, self and the environment. An increasing ability of children to describe the odor facets of their perceptual world was found between 6 and 10 years, partly due to …