Human behavioural discrimination of human, chimpanzee and macaque affective vocalisations is reflected by the neural response in the superior temporal sulcus

Accurate perception of the emotional content of vocalisations is essential for successful social communication and interaction. However, it is not clear whether our ability to perceive emotional cues from vocal signals is specific to human signals, or can be applied to other species' vocalisations. Here, we address this issue by evaluating the perception and neural response to affective vocalisations from different primate species (humans, chimpanzees and macaques). We found that the ability of human participants to discriminate emotional valence varied as a function of phylogenetic distance between species. Participants were most accurate at discriminating the emotional valence of human vocalisations, followed by chimpanzee vocalisations. They were, however, unable to accurately discriminate the valence of macaque vocalisations. Next, we used fMRI to compare human brain responses to human, chimpanzee and macaque vocalisations. We found that regions in the superior temporal lobe that are closely associated with the perception of complex auditory signals, showed a graded response to affective vocalisations from different species with the largest response to human vocalisations, an intermediate response to chimpanzees, and the smallest response to macaques. Together, these results suggest that neural correlates of differences in the perception of different primate affective vocalisations are found in auditory regions of the human brain and correspond to the phylogenetic distances between the species

Referential gestures are not ubiquitous in wild chimpanzees : alternative functions for exaggerated loud scratch gestures

Royal Zoological Society of Scotland for providing core funding for Budongo Conservation Field Station. This work was supported by the ERC grant awarded to KS (ERC_CoG 2016_724608).A fundamental aspect of human communication is our ability to refer to external objects and events through both words and gestures (such as pointing), yet the evolutionary origins of such signals remain obscure. Apes, living in their natural environments, rarely or never point, but it has been claimed that male chimpanzees, Pan troglodytes schweinfurthii, from the Ngogo community, Uganda, habitually use exaggerated loud scratches (ELSs) to refer to specific body locations where they wish to be groomed (Pika & Mitani, 2006, Current Biology, 16(6), 191–192). This study suggested continuity between referential abilities in humans and our closest living relatives, making it an important finding to replicate in other populations. Hence here, we compared whether ELSs are used in a referential manner across four wild communities of eastern chimpanzees (Ngogo, Kanyawara, Sonso and Waibira). Our data show that scratchers were significantly more likely to receive grooming in the scratched location at Ngogo compared to the other three sites. At the latter sites this response occurred at low rates and signallers did not seem to pursue this goal. This suggests that ELSs do not function referentially at these sites, and the published findings from Ngogo were not replicated. Further exploration into alternative functions of ELSs in the Kanyawara community revealed that, in this community, this signal functions to initiate grooming bouts and to reengage partners during grooming pauses. Individuals who produced the signal to initiate grooming were likely to offer grooming. In contrast, during grooming bouts, groomers produced ELSs to request reciprocation of grooming from their partner. Our study demonstrates that chimpanzees do not ubiquitously use the ELS in a referential manner, but that they can use this gesture in a highly flexible fashion, with signal function depending on the intricate details of the social contexts in which they are produced.Publisher PDFPeer reviewe

Functionally referential communication in a chimpanzee

The evolutionary origins of the use of speech signals to refer to events or objects in the world have remained obscure. Although functionally referential calls have been described in some monkey species [1 and 2], studies with our closest living relatives, the great apes, have not generated comparable findings. These negative results have been taken to suggest that ape vocalizations are not the product of their otherwise sophisticated mentality and that ape gestural communication is more informative for theories of language evolution [3 and 4]. We tested whether chimpanzee rough grunts, which are produced during feeding contexts [5, 6, 7 and 8], functioned as referential signals. Individuals produced acoustically distinct types of “rough grunts” when encountering different foods. In a naturalistic playback experiment, a focal subject was able to use the information conveyed by these calls produced by several group mates to guide his search for food, demonstrating that the different grunt types were meaningful to him. This study provides experimental evidence that our closest living relatives can produce and understand functionally referential calls as part of their natural communication. We suggest that these findings give support to the vocal rather than gestural theories of language evolution

Food-associated calls in chimpanzees: Responses to food types or food preferences?

Chimpanzees produce specific vocalizations, ‘rough grunts’, when encountering food, and it has been suggested that these calls vary acoustically depending on the food type discovered by the caller. Nearby listeners often behave as if the calls are meaningful to them, indicating that the calls may function as referential labels for particular foods. We investigated whether rough grunt variants are the result of callers responding to specific food types or relative food preferences. We recorded calls from captive individuals in response to nine different food items, which could be ranked as high, medium or low preference. Individuals consistently produced three acoustically distinct grunt variants to the three food preference classes. There was no evidence that chimpanzees produced individual labels for food types of low and medium preference. However, calls to high-preference food types differed significantly in their acoustic structure. These acoustic patterns remained stable over trials, suggesting that rough grunts have the potential to serve as semantic labels for individual high-preference food types. We were unable to replicate these findings with a set of recordings from the wild, although most other aspects of calling behaviour remained identical. We discuss these discrepancies between the wild and captivity and suggest that the emergence of referential labels for food items may be a by-product of the special circumstances found in captive settings

Human listeners’ perception of behavioural context and core affect dimensions in chimpanzee vocalizations

Vocalisations linked to emotional states are partly conserved among phylogenetically related species. This continuity may allow humans to accurately infer affective information from vocalisations produced by chimpanzees. In two pre-registered experiments, we examine human listeners’ ability to infer behavioural contexts (e.g., discovering food) and core affect dimensions (arousal and valence) from 155 vocalisations produced by 66 chimpanzees in 10 different positive and negative contexts at high, medium, or low arousal levels. In Experiment 1, listeners (n = 310), categorised the vocalisations in a forced-choice task with 10 response options, and rated arousal and valence. In Experiment 2, participants (n = 3120) matched vocalisations to production contexts using Yes/No response options. The results show that listeners were accurate at matching vocalisations of most contexts in addition to inferring levels of arousal and valence. Judgments were more accurate for negative as compared to positive vocalisations. An acoustic analysis demonstrated that, listeners made use of brightness and duration cues, and relied on noisiness in making context judgements, and pitch to infer core affect dimensions. Overall, the results suggest that human listeners can infer affective information from chimpanzee vocalisations beyond core affect dimensions, indicating phylogenetic continuity in the mapping of vocalisations to behavioural contexts

Resistência parasitária em helmintos de eqüídeos e propostas de manejo Parasite resistance on helminths of equids and management proposal’s

Os eqüinos apresentam uma grande variedade de parasitas em sua fauna helmíntica, e algumas espécies/gêneros são de relevada importância, como: Parascaris equorum, Anoplocephala perfoliata, Oxyuris equi, Cyathostomum spp. e Strongylus spp. O controle destas infecções depende principalmente da utilização de produtos antiparasitários de forma supressiva ou estratégica e, em menor escala, de forma curativa. O tratamento supressivo é o fator mais importante na promoção da seleção de organismos resistentes, prejudicando a sustentabilidade de qualquer programa sanitário. As formas de detecção da resistência parasitária são onerosas e as mais comuns expressam resultados imprecisos. Entretanto, estas técnicas servem para monitorar a evolução e determinar os organismos envolvidos. A combinação de drogas é uma ferramenta que deve ser utilizada com muita cautela, pois esta alternativa não garante uma redução significativa de organismos resistentes aos compostos envolvidos. O objetivo deste artigo é apresentar formas de planejamento que auxiliem a melhorar a condição sanitária, o bem-estar dos animais e preserve o efeito tóxico dos produtos antiparasitários.<br>Equines harbour a variety of parasitic organisms on their helminth fauna and there are a few species/genus of interest, such as: Parascaris equorum, Anoplocephala perfoliata, Oxyuris equi, Cyathostomum spp. and Strongylus spp. The control of these infections relies mostly on the suppressive or strategic usage of antiparasitic compounds, and to a less extent on curative/salvage treatments. Suppressive treatment is the most important factor regarding the selection of resistant organisms, causing the impairment of sanitary programs. Detection methods of parasite resistance are expensive and the most common ones express variable results. Although, these techniques allow monitoring the evolution and the determination of which organisms are involved. Drug combination is a toll that should be used with caution, because it may not reduce the presence of resistant organisms to the compounds involved. The objective of this article is to demonstrate control alternatives that would contribute to sanitary management, to improve animal welfare and to preserve the toxic effect of the antiparasitic products

The benzimidazole anthelmintic agents - a review

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