55 research outputs found
Raven food calls indicate sender's age and sex.
BACKGROUND: Acoustic parameters of animal signals have been shown to correlate with various phenotypic characteristics of the sender. These acoustic characteristics can be learned and categorized and thus are a basis for perceivers' recognition abilities. One of the most demanding capacities is individual recognition, achievable only after repeated interactions with the same individual. Still, class-level recognition might be potentially important to perceivers who have not previously encountered callers but can classify unknown individuals according to the already learned categories. Especially for species with high fission-fusion dynamics that repeatedly encounter unknown individuals it may be advantageous to develop class-level recognition. We tested whether frequency-, temporal-, and amplitude-related acoustic parameters of vocalizations emitted by ravens, a species showing high fission-fusion dynamics in non-breeder aggregations, are connected to phenotypic characteristics and thus have the potential for class-level recognition. RESULTS: The analysis of 418 food calls revealed that some components summarizing acoustic parameters were differentiated by age-classes and sex. CONCLUSIONS: Together, the results provide evidence for the co-variation of vocal characteristics and respective sex and age categories, a prerequisite for class-level recognition in perceivers. Perceivers that are ignorant of the caller's identity can thus potentially recognize these class-level differences for decision-making processes in feeding contexts
overview and meta-analysis of neuroimaging studies on motor conversion disorder
Background Conversion Disorders (CD) are prevalent functional disorders.
Although the pathogenesis is still not completely understood, an interaction
of genetic, neurobiological, and psychosocial factors is quite likely. The aim
of this study is to provide a systematic overview on imaging studies on CDs
and investigate neuronal areas involved in Motor Conversion Disorders (MCD).
Methods A systematic literature search was conducted on CD. Subsequently a
meta-analysis of functional neuroimaging studies on MCD was implemented using
an Activation Likelihood Estimation (ALE). We calculated differences between
patients and healthy controls as well as between affected versus unaffected
sides in addition to an overall analysis in order to identify neuronal areas
related to MCD. Results Patients with MCD differ from healthy controls in the
amygdala, superior temporal lobe, retrosplenial area, primary motor cortex,
insula, red nucleus, thalamus, anterior as well as dorsolateral prefrontal and
frontal cortex. When comparing affected versus unaffected sides, temporal
cortex, dorsal anterior cingulate cortex, supramarginal gyrus, dorsal temporal
lobe, anterior insula, primary somatosensory cortex, superior frontal gyrus
and anterior prefrontal as well as frontal cortex show significant
differences. Conclusions Neuronal areas seem to be involved in the
pathogenesis, maintenance or as a result of MCD. Areas that are important for
motor-planning, motor-selection or autonomic response seem to be especially
relevant. Our results support the emotional unawareness theory but also
underline the need of more support by conduction imaging studies on both CD
and MCD
Field Propagation Experiments of Male African Savanna Elephant Rumbles: A Focus on the Transmission of Formant Frequencies.
African savanna elephants live in dynamic fissionâ»fusion societies and exhibit a sophisticated vocal communication system. Their most frequent call-type is the 'rumble', with a fundamental frequency (which refers to the lowest vocal fold vibration rate when producing a vocalization) near or in the infrasonic range. Rumbles are used in a wide variety of behavioral contexts, for short- and long-distance communication, and convey contextual and physical information. For example, maturity (age and size) is encoded in male rumbles by formant frequencies (the resonance frequencies of the vocal tract), having the most informative power. As sound propagates, however, its spectral and temporal structures degrade progressively. Our study used manipulated and resynthesized male social rumbles to simulate large and small individuals (based on different formant values) to quantify whether this phenotypic information efficiently transmits over long distances. To examine transmission efficiency and the potential influences of ecological factors, we broadcasted and re-recorded rumbles at distances of up to 1.5 km in two different habitats at the Addo Elephant National Park, South Africa. Our results show that rumbles were affected by spectralâ»temporal degradation over distance. Interestingly and unlike previous findings, the transmission of formants was better than that of the fundamental frequency. Our findings demonstrate the importance of formant frequencies for the efficiency of rumble propagation and the transmission of information content in a savanna elephant's natural habitat
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How intelligent is a cephalopod? Lessons from comparative cognition.
The soft-bodied cephalopods including octopus, cuttlefish, and squid are broadly considered to be the most cognitively advanced group of invertebrates. Previous research has demonstrated that these large-brained molluscs possess a suite of cognitive attributes that are comparable to those found in some vertebrates, including highly developed perception, learning, and memory abilities. Cephalopods are also renowned for performing sophisticated feats of flexible behaviour, which have led to claims of complex cognition such as causal reasoning, future planning, and mental attribution. Hypotheses to explain why complex cognition might have emerged in cephalopods suggest that a combination of predation, foraging, and competitive pressures are likely to have driven cognitive complexity in this group of animals. Currently, it is difficult to gauge the extent to which cephalopod behaviours are underpinned by complex cognition because many of the recent claims are largely based on anecdotal evidence. In this review, we provide a general overview of cephalopod cognition with a particular focus on the cognitive attributes that are thought to be prerequisites for more complex cognitive abilities. We then discuss different types of behavioural flexibility exhibited by cephalopods and, using examples from other taxa, highlight that behavioural flexibility could be explained by putatively simpler mechanisms. Consequently, behavioural flexibility should not be used as evidence of complex cognition. Fortunately, the field of comparative cognition centres on designing methods to pinpoint the underlying mechanisms that drive behaviours. To illustrate the utility of the methods developed in comparative cognition research, we provide a series of experimental designs aimed at distinguishing between complex cognition and simpler alternative explanations. Finally, we discuss the advantages of using cephalopods to develop a more comprehensive reconstruction of cognitive evolution.A.K.S. was supported by an Endeavour Research Fellowship funded by the Australian Government and was also supported by a Newton International Fellowship funded by the Royal Society. P.A. received support from the Cambridge Philosophical Society (Research Studentship Ref. 123 S52/002/19). A European Research Council under the European Unionâs Seventh Framework Programme (FP7/2007-2013)/ERC Grant Agreement No. 3399933 was awarded to N.S.C., which supported both M.B and N.S.C
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How flexible is tool use in Eurasian jays (Garrulus glandarius)?
Eurasian jays (Garrulus glandarius) do not habitually use tools, yet they can be trained to solve object-dropping tasks, i.e., to insert a tool into an apparatus to release a food reward. Previous research suggests that these jays can learn a preference toward functional tools â objects allowing them to obtain a food reward placed inside an apparatus â according to their density (Cheke et al., 2011). However, it is not yet known whether they can also select functional tools (tool selectivity) according to other physical properties such as size and shape, and use different kinds of tools to solve a similar task. Here we conducted three object-dropping experiments aimed at exploring these abilities in Eurasian jays. In Experiment 1, jays tended to select large stones as tools irrespective of the diameter of the apparatus. However, jays progressively developed a preference for the small tool, which was functional with both the wide and the narrow apparatuses. In Experiment 2, only vertically oriented long stones could fit into the narrow apparatus, whereas both long and round stones were functional with the wide apparatus. Jays showed a preference for the long stone and, with the narrow apparatus, tended to achieve the correct manipulation after one or more unsuccessful attempts. In Experiment 3, jays were able to use sticks and adopt a novel technique on the same object-dropping apparatus, thus providing the first evidence that Eurasian jays can use sticks as tools. Taken together, these results do not support the notion that tool selectivity abilities can be found in Eurasian jays but nonetheless show that these corvids can use different kinds of tools to solve similar tasks.P.A. received financial support by the Accademia Nazionale dei Lincei
Chronic Pain and Sleep Disorders in Primary Care.
BACKGROUND: Chronic pain (CP) and sleep disorders (SD) are highly prevalent in the general population. However, comprehensive data regarding the prevalence and characteristics of pain and SD in primary care are rare. METHODS: From N = 578 patients N = 570 were included within 8 weeks (mean age: 50.8 ± 18.7 years, females: 289). Sociodemographic data, Insomnia Severity Index (ISI), and parts of a self-report questionnaire for pain (Multidimensional German Pain Questionnaire) were recorded and additional medical information (pain medication, sleep medication) was gathered from the patient charts. RESULTS: Of the total sample, 33.2% (n = 189) suffer from CP (pain â„ 6 months) and 29.1% (n = 166) from SD. 45.5% of the CP patients suffer from SD and 26.5% from clinical insomnia (ISI â„ 15). SD (ÎČ = 0.872, SE = 0.191,âât = 4,572, p < 0.001, CI [0.497; 1.246]) and older age (ÎČ = 0.025, SE = 0.005, t = 5.135, p < 0.001, CI [0.015; 0.035]) were significantly associated with pain experience. CONCLUSION: About a quarter of CP patients suffer from clinical insomnia. The suggested bidirectional relation should be considered during comprehensive assessment and treatment of patients
Multimodal signaling in the Small Torrent Frog (Micrixalus saxicola) in a complex acoustic environment.
Many animals use multimodal (both visual and acoustic) components in courtship signals. The acoustic communication of anuran amphibians can be masked by the presence of environmental background noise, and multimodal displays may enhance receiver detection in complex acoustic environments. In the present study, we measured sound pressure levels of concurrently calling males of the Small Torrent Frog (Micrixalus saxicola) and used acoustic playbacks and an inflatable balloon mimicking a vocal sac to investigate male responses to controlled unimodal (acoustic) and multimodal (acoustic and visual) dynamic stimuli in the frogs' natural habitat. Our results suggest that abiotic noise of the stream does not constrain signal detection, but males are faced with acoustic interference and masking from conspecific chorus noise. Multimodal stimuli elicited greater response from males and triggered significantly more visual signal responses than unimodal stimuli. We suggest that the vocal sac acts as a visual cue and improves detection and discrimination of acoustic signals by making them more salient to receivers amidst complex biotic background noise
Neural correlates of somatoform disorders from a meta-analytic perspective on neuroimaging studies.
Somatoform disorders (SD) are common medical disorders with prevalence rates between 3.5% and 18.4%, depending on country and medical setting. SD as outlined in the ICD-10 exhibits various biological, social, and psychological pathogenic factors. Little is known about the neural correlates of SD. The aims of this meta-analysis are to identify neuronal areas that are involved in SD and consistently differ between patients and healthy controls. We conducted a systematic literature research on neuroimaging studies of SD. Ten out of 686 studies fulfilled the inclusion criteria and were analyzed using activation likelihood estimation. Five neuronal areas differ between patients with SD and healthy controls namely the premotor and supplementary motor cortexes, the middle frontal gyrus, the anterior cingulate cortex, the insula, and the posterior cingulate cortex. These areas seem to have a particular importance for the occurrence of SD. Out of the ten studies two did not contribute to any of the clusters. Our results seem to largely overlap with the circuit network model of somatosensory amplification for SD. It is conceivable that functional disorders, independent of the clinical impression, show similar neurobiological processes. While overlaps do occur it is necessary to understand single functional somatic syndromes and their aetiology for future research, terminology, and treatment guidelines
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Grow Smart and Die Young: Why Did Cephalopods Evolve Intelligence?
Intelligence in large-brained vertebrates might have evolved through independent, yet similar processes based on comparable socioecological pressures and slow life histories. This convergent evolutionary route, however, cannot explain why cephalopods developed large brains and flexible behavioural repertoires: cephalopods have fast life histories and live in simple social environments. Here, we suggest that the loss of the external shell in cephalopods (i) caused a dramatic increase in predatory pressure, which in turn prevented the emergence of slow life histories, and (ii) allowed the exploitation of novel challenging niches, thus favouring the emergence of intelligence. By highlighting convergent and divergent aspects between cephalopods and large-brained vertebrates we illustrate how the evolution of intelligence might not be constrained to a single evolutionary route.M.B., N.S.C. were funded by the European Research Council under the European Unionâs Seventh Framework Programme (FP7/2007-2013)/ERC Grant Agreement No. 3399933, awarded to N.S.C. A.S. was supported by an Endeavour Research Fellowship, funded by the Australian Government
Waste Disposal Sites as All-You-Can Eat Buffets for Carrion Crows (Corvus corone).
In cities and densely populated areas, several corvid species are considered nuisance animals. In Austria, particularly carrion (Corvus corone) and hooded crows (C. cornix) are regarded as pests by the general public that frequently cause damage to crops, feed on human waste, and thus spread trash. We conducted a detailed one-year field survey to estimate the abundance of carrion crows in relation to potential anthropogenic food sources and reference sites in the Austrian Rhine valley. Our results demonstrated that the number and proximity of waste management facilities, animal feeding areas, and agricultural areas, and the productive capacity of agricultural areas, predominantly influenced habitat choice and abundance of carrion crows. In the current study, the probability of observing more than two carrion crows at a survey site decreased with increasing human population density. Moreover, the abundance of crows increased despite a continuous increase in crow hunting kills registered during the past 25 years. Our study suggests a regionally comprehensive waste management plan could serve as a promising strategy to manage nuisance birds. A reduction in anthropogenic food supply through improved waste management practices is required for long-term, sustainable management to limit the abundance of crow populations in and close to urban environments.This research was funded by InaturaâNaturschau Dornbirn GmbH with the follwing project âname âPopulationsrelevante EinflĂŒsse von Biogas-, GrĂŒnmĂŒllanlagen und ehemaligen Deponien auf die Corvidenfauna im Vorarlberger Rheintal: historische und rezente Entwicklungenâ and was granted to Markus Boeckle
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