Academic literature on the topic 'Discrimination sociale olfactive'

Primates were traditionally thought to have a reduced sense of smell. Although there is now evidence that olfaction plays a greater role in primate social life than previously assumed, research on the sense of smell in non-human apes is scarce. Chimpanzees sniff the ground and vegetation on boundary patrols, but the function of this behaviour is unclear. Since chimpanzees are highly territorial and can kill individuals that do not belong to their own community, sniffing might function to gather information about conspecifics, particularly concerning group membership and kinship. To investigate whether chimpanzees recognize group members and kin via olfactory cues, we conducted behavioural bioassays on two groups of chimpanzees at Leipzig Zoo. In a pilot study, we found that chimpanzees responded more strongly to urine than to faeces or body odour. We then presented urine from group members, outgroup individuals and an unscented control in aerated boxes using a simultaneous discrimination task. The first behaviour after a chimpanzee first approached a box was related to olfaction (sniffing, nose within 20 cm, licking) in 83% of cases, highlighting the importance of olfaction as a general investigation mechanism in this species. Chimpanzees sniffed significantly longer at urine stimuli than the control and significantly longer at odours from outgroup individuals than those from group members. Furthermore, the duration of sniffing was positively correlated with relatedness. Our results suggest that chimpanzees use olfactory cues to obtain information about social relationships and fill a gap in our understanding of primate chemical communication.

An ability to recognise and discriminate between group and non-group members is essential for most group-living species. Several different sensory modalities may be utilised for social recognition, the most notable of which is olfaction. Among insects, members of the order Blattodea (cockroaches, termites) exhibit a diverse range of social systems and provide an excellent model for examining the role of chemical communication in group discrimination. We experimentally tested the importance of chemical cues in the association preferences of the subsocial Australian wood-boring cockroach, Panesthia australis. Using a series of dichotomous choice trials, we found that individuals preferred conspecific odour cues over those of an unscented peatmoss control. We then gave cockroaches a choice between the odour cues of cockroaches from different logs, and found that they did not exhibit a preference for the cues of individuals from their own log versus those from different logs within the same locality. However, cockroaches exhibited a strong preference for cues taken from individuals from a geographically distant population. Our findings suggest that P. australis engages in group discrimination, and that patterns of association may reflect an underlying preference for unfamiliar and/or genetically dissimilar individuals in a species encumbered by restricted gene flow.

Olfaction is the dominant sensory modality in rodents, and is crucial for regulating social behaviors, including parental care. Paternal care is rare in rodents, but can have significant consequences for offspring fitness, suggesting a need to understand the factors that regulate its expression. Pup-related odor cues are critical for the onset and maintenance of paternal care. Here, I consider the role of olfaction in the expression of paternal care in rodents. The medial preoptic area shares neural projections with the olfactory and accessory olfactory bulbs, which are responsible for the interpretation of olfactory cues detected by the main olfactory and vomeronasal systems. The olfactory, trace amine, membrane-spanning 4-pass A, vomeronasal 1, vomeronasal 2 and formyl peptide receptors are all involved in olfactory detection. I highlight the roles that 10 olfactory genes play in the expression of direct paternal care behaviors, acknowledging that this list is not exhaustive. Many of these genes modulate parental aggression towards intruders, and facilitate the recognition and discrimination of pups in general. Much of our understanding comes from studies on non-naturally paternal laboratory rodents. Future studies should explore what role these genes play in the regulation and expression of paternal care in naturally biparental species.

In this article, I show how groups and individuals maintain racialized symbolic boundaries at the micro-level of personal interactions. Using data collected during an ethnographic study in Athens, Greece, where I worked as a fruit vendor in a street market, I detail how local Greek vendors and immigrant workers use language, gesture, olfaction, along with their interpretations of faith and sexuality to reproduce patterns of social distance that allow for racialized stigma and discrimination. I apply the framework of symbolic interactionism and draw from literature on symbolic boundaries to explore how immigrant street market workers experience and resist racialization throughout the interaction order. I show that racialization underlies perceptions of the immigrant “other,” especially in the case of Greece where race is often ignored as a crucial factor.

An olfactory visualization system conducts a qualitative or quantitative analysis of volatile organic compounds (VOCs) by utilizing the sensor array made of color sensitive dyes. The reaction chamber is important to the sensor array’s sufficient and even exposure to VOCs. In the current work, a reaction chamber with an arc baffle embedded in the front of the air inlet for drainage effect was designed. The velocity of field and particle distribution of flow field in the reaction chamber was simulated by COMSOL Multiphysics. Through repeated simulation, the chamber achieved optimal result when the baffle curvature was 3.1 and the vertical distance between the baffle front end and the air inlet was 1.6 cm. Under the new reaction chamber, principal component analysis (PCA) and linear discriminant analysis (LDA) were employed to identify vinegar samples with different storage time through analyzing their VOCs. The LDA model achieved optimal performance when 8 principal components (PCs) were used, and the recognition rate was 95% in both training and prediction sets. The new reaction chamber could improve the stability and precision of an olfactory visualization system for VOCs analysis, and achieve the accurate differentiation and rapid discrimination of Zhenjiang vinegar with different storage time.

Social insects have evolved sophisticated recognition systems enabling them to accept nest-mates but reject alien conspecifics. In the social wasp, Liostenogaster flavolineata (Stenogastrinae), individuals differ in their cuticular hydrocarbon profiles according to colony membership; each female also possesses a unique (visual) facial pattern. This species represents a unique model to understand how vision and olfaction are integrated and the extent to which wasps prioritize one channel over the other to discriminate aliens and nest-mates. Liostenogaster flavolineata females are able to discriminate between alien and nest-mate females using facial patterns or chemical cues in isolation. However, the two sensory modalities are not equally efficient in the discrimination of ‘friend’ from ‘foe’. Visual cues induce an increased number of erroneous attacks on nest-mates (false alarms), but such attacks are quickly aborted and never result in serious injury. Odour cues, presented in isolation, result in an increased number of misses: erroneous acceptances of outsiders. Interestingly, wasps take the relative efficiencies of the two sensory modalities into account when making rapid decisions about colony membership of an individual: chemical profiles are entirely ignored when the visual and chemical stimuli are presented together. Thus, wasps adopt a strategy to ‘err on the safe side’ by memorizing individual faces to recognize colony members, and disregarding odour cues to minimize the risk of intrusion from colony outsiders.

Autism spectrum disorder (ASD) is mostly diagnosed according to behavioral symptoms in sensory, social, and motor domains. Improper motor functioning, during diagnosis, involves the qualitative evaluation of stereotyped and repetitive behaviors, while quantitative methods that classify body movements’ frequencies of children with ASD are less addressed. Recent advances in neuroscience, technology, and data analysis techniques are improving the quantitative and ecological validity methods to measure specific functioning in ASD children. On one side, cutting-edge technologies, such as cameras, sensors, and virtual reality can accurately detect and classify behavioral biomarkers, as body movements in real-life simulations. On the other, machine-learning techniques are showing the potential for identifying and classifying patients’ subgroups. Starting from these premises, three real-simulated imitation tasks have been implemented in a virtual reality system whose aim is to investigate if machine-learning methods on movement features and frequency could be useful in discriminating ASD children from children with typical neurodevelopment. In this experiment, 24 children with ASD and 25 children with typical neurodevelopment participated in a multimodal virtual reality experience, and changes in their body movements were tracked by a depth sensor camera during the presentation of visual, auditive, and olfactive stimuli. The main results showed that ASD children presented larger body movements than TD children, and that head, trunk, and feet represent the maximum classification with an accuracy of 82.98%. Regarding stimuli, visual condition showed the highest accuracy (89.36%), followed by the visual-auditive stimuli (74.47%), and visual-auditive-olfactory stimuli (70.21%). Finally, the head showed the most consistent performance along with the stimuli, from 80.85% in visual to 89.36% in visual-auditive-olfactory condition. The findings showed the feasibility of applying machine learning and virtual reality to identify body movements’ biomarkers that could contribute to improving ASD diagnosis.

AbstractOlfactory communication is highly important for nocturnal mammals, especially for solitary foragers, but knowledge is still limited for nocturnal primates. Mouse lemurs (Microcebus spp.) are nocturnal solitary foragers with a dispersed lifestyle and frequently use chemo-sensory signalling behaviour for governing social interactions. Different mouse lemur species can co-occur in a given forest but it is unknown whether olfaction is involved in species recognition. We first screened 24 captive mouse lemurs (9 M. murinus, 15 M. lehilahytsara) for their olfactory learning potential in an experimental arena and then tested the species discrimination ability with urine odour in an operant conditioning paradigm in four individuals. The majority of the screened animals (75%) did not pass the screening criteria within a 2-week test period. However, all four final test animals, two M. murinus and two M. lehilahytsara, were successfully trained in a 5-step-conditioning process to reliably discriminate conspecific from heterospecific urine odour (requiring an overall median of 293 trials). Findings complement previous studies on the role of acoustic signalling and suggest that olfaction may be an important additional mechanism for species discrimination.

Background and Hypothesis: 
 Social-enhanced safety learning is a psychosocial process used to reduce fear or anxiety by learning to discriminate fearful versus safe stimuli via a social safety cue. Learning to associate safety with a social cue requires intact social memory. Preliminary data in rats suggests inhibiting the orbitofrontal cortex (OFC) with pharmacologic agents impairs social memory. However, the specific mechanism by which OFC regulates social memory remains unknown. Because the OFC has broad functional implications including valuation, decision-making, social and emotional behaviors, olfaction, and non-social memory, we hypothesized that OFC inhibition was disrupting one of these specific processes, resulting in social memory impairment. 
 Experimental Design or Project Methods: 
 Cannulated adult male Sprague-Dawley rats were injected bilaterally in OFC with either saline vehicle, or 0.9 mM Muscimol, a GABAA agonist that transiently inhibits local neuronal activity. At 10 minutes post-injection, rats underwent behavior testing for either: social recognition, novel object recognition, social preference (innate gregariousness), or olfactory discrimination. 
 Results: 
 Rats receiving Muscimol injection, but not rats receiving vehicle injection, demonstrated statistically significant impairment of social recognition, observed as a failure to discriminate between two conspecifics. Alternatively, rats receiving Muscimol injection, but not rats receiving vehicle injection, did not demonstrate statistically significant impairment of novel object (non-social) recognition, innate gregariousness, or olfaction, which were all intact in vehicle injected rats. 
 Conclusion and Potential Impact: 
 These data suggest OFC may be part of a unique neural circuit specific to social memory. Delineating the circuitry of social memory from non-social memory offers exciting possibilities in the advancement of precision therapies.

La perception sensorielle est propre à chaque individu. Elle découle du patrimoine génétique (qui définit les récepteurs sensoriels), mais varie en fonction de la maturation et de l’expérience d’un individu. En ce sens, l’étude du bébé nous a permis de tester à la fois 1) l’effet de la maturation, en comparant la perception des bébés avec celle des adultes et 2) l’effet de l’expérience sensorielle précoce, en comparant la perception sensorielle de bébés nés à terme ou prématurés pour un même âge donné. Nos résultats ont souligné une perception sensorielle plus étendue chez le bébé que chez l’adulte, via la perception de stimulations tactiles très fines ou encore la perception d’ultrasons, qui ne sont plus perçus à l’âge adulte. Les mécanismes de maturation des organes sensoriels et de « recentrage sensoriel » envers les stimulations pertinentes, pouvant intervenir au cours du temps, ont été présentés. Nous avons également montré une réactivité particulièrement marquée des bébés prématurés, en comparaison avec les bébés nés à terme. Différents mécanismes sous-jacents potentiels tels qu’une adaptation de la sélectivité neuronale aux stimulations environnementales, une plasticité cérébrale conservée/retardée, ou encore le développement d’une hypersensibilité ont été discutés. En sus du cœur de cette thèse, nous nous sommes intéressés à l’ « Umwelt » social du bébé, en étudiant 1) ses capacités de perception et de discrimination des odeurs corporelles humaines et 2) sa capacité à s’exprimer sur sa perception sensorielle. Nous avons montré que le bébé est un être très réceptif à son monde social, capable de discriminer entre les odeurs de ses partenaires sociaux. De plus, le bébé est également très expressif sur sa perception sensorielle, notamment via l’utilisation d’un répertoire vocal complexe (au-delà des pleurs), dont certains types de vocalisations pourraient refléter son état de confort ou d’inconfort. Les résultats de cette thèse ouvrent de nombreuses pistes de réflexion en termes d’adaptations des pratiques néonatales<br>Sensory perception is specific to each individual. It results from the gene pool (which defines the sensory receptors), but varies depending on maturation and experience. In this sense, the study of babies has enabled us to test both 1) the effect of maturation by comparing the babies’ sensory perception to those of adults and 2) the effect of early stage sensory perception by comparing the sensory perception of preterm and full-term infants at a same post-conception age (i.e. term-aged infants). Our results underlined a larger sensory perception in babies than in adults, through the perception of very subtle tactile stimulations, or else the perception of ultrasounds, that cannot be perceived by grown-ups. The mechanisms of the maturation of sensory organs and of ‘’sensory recentering‘’ towards relevant simulations that can happen in the course of time have been presented. We have also shown a particularly strong reactivity of preterm babies in comparison to full-term babies. Various potential subjacent mechanisms such as a neuronal selectivity adaptation to environmental stimulations, a maintained/ delayed cerebral plasticity or else the development of a hypersensitivity have been discussed. In addition to the core of this thesis, we have taken an interest in the baby’s social “Umwelt” and have studied 1) his abilities in perception and discrimination between human body odours and 2) his ability to express his sensory perception. We have shown that babies are very responsive to their social world, capable of discrimination between different social partners’ odours. Furthermore, babies also are highly expressive when it comes to their sensory perception, especially through the use of a complex vocal repertoire (beyond cries/tears). Indeed, some types of these vocalisations could reflect his state of comfort or discomfort. The results of this thesis open numerous grounds for thought in terms of neonatal care adaptations