Neural Correlates of Experience-Induced Deficits in Learned Vocal Communication

Songbirds are one of the few vertebrate groups (including humans) that evolved the ability to learn vocalizations. During song learning, social interactions with adult models are crucial and young songbirds raised without direct contacts with adults typically produce abnormal songs showing phonological and syntactical deficits. This raises the question of what functional representation of their vocalizations such deprived animals develop. Here we show that young starlings that we raised without any direct contact with adults not only failed to differentiate starlings' typical song classes in their vocalizations but also failed to develop differential neural responses to these songs. These deficits appear to be linked to a failure to acquire songs' functions and may provide a model for abnormal development of communicative skills, including speech

Lower attention to daily environment: a novel cue for detecting chronic horses' back pain?

Chronic pain is thought to affect patients' cognitive functioning, including attention. Loss of attention is likely to have an impact on the execution of daily tasks, and, therefore, to have negative effects. However, relationships between chronic pain and cognitive deficits are still debated. Pre-clinical studies using laboratory animals prove useful to model pain-related cognitive impairment, but animal models had to predict effects in the real world. This study investigates attentional engagement of domestic horses by comparing observations in a home setting and evaluations of vertebral disorders. We found that lower attentional engagement and the level of back disorders were correlated. Two different evaluation techniques of the state of horses' spines gave similar results. We suggest that novel animal models would prove useful for identifying spontaneous behaviours indicative of chronic pain. We suggest that more ethological studies in human patients' home environments would help to improve our understanding of the processes involved. Finally, these results yield interesting indications for evaluating animal welfare, as attentional engagement could become a reliable indicator of chronic pain and thus a useful tool for identification of suffering individuals

Investigating attentional processes in depressive-like domestic horses (Equus caballus).

Some captive/domestic animals respond to confinement by becoming inactive and unresponsive to external stimuli. Human inactivity is one of the behavioural markers of clinical depression, a mental disorder diagnosed by the co-occurrence of symptoms including deficit in selective attention. Some riding horses display 'withdrawn' states of inactivity and low responsiveness to stimuli that resemble the reduced engagement with their environment of some depressed patients. We hypothesized that 'withdrawn' horses experience a depressive-like state and evaluated their level of attention by confronting them with auditory stimuli. Five novel auditory stimuli were broadcasted to 27 horses, including 12 'withdrawn' horses, for 5 days. The horses' reactions and durations of attention were recorded. Non-withdrawn horses reacted more and their attention lasted longer than that of withdrawn horses on the first day, but their durations of attention decreased over days, but those of withdrawn horses remained stable. These results suggest that the withdrawn horses' selective attention is altered, adding to already evidenced common features between this horses' state and human depression

A Potential Neural Substrate for Processing Functional Classes of Complex Acoustic Signals

Categorization is essential to all cognitive processes, but identifying the neural substrates underlying categorization processes is a real challenge. Among animals that have been shown to be able of categorization, songbirds are particularly interesting because they provide researchers with clear examples of categories of acoustic signals allowing different levels of recognition, and they possess a system of specialized brain structures found only in birds that learn to sing: the song system. Moreover, an avian brain nucleus that is analogous to the mammalian secondary auditory cortex (the caudo-medial nidopallium, or NCM) has recently emerged as a plausible site for sensory representation of birdsong, and appears as a well positioned brain region for categorization of songs. Hence, we tested responses in this non-primary, associative area to clear and distinct classes of songs with different functions and social values, and for a possible correspondence between these responses and the functional aspects of songs, in a highly social songbird species: the European starling. Our results clearly show differential neuronal responses to the ethologically defined classes of songs, both in the number of neurons responding, and in the response magnitude of these neurons. Most importantly, these differential responses corresponded to the functional classes of songs, with increasing activation from non-specific to species-specific and from species-specific to individual-specific sounds. These data therefore suggest a potential neural substrate for sorting natural communication signals into categories, and for individual vocal recognition of same-species members. Given the many parallels that exist between birdsong and speech, these results may contribute to a better understanding of the neural bases of speech

JEC Tank-to-Wheels Report v5: Heavy duty vehicles: Well-to-Wheels analysis of future automotive fuels and powertrains in the European context

In this study typical figures for fuel consumption (FC), CO2 and CO2-equivalent emissions as well as energy consumption of current and future propulsion and fuel configurations for heavy duty vehicles (HDV) have been assessed. This report covers the Tank-to-Wheels (TTW) part of a comprehensive Well-to-Wheel (WTW) analysis. The parts of the study related to Well-to-Tank (WTT) analysis and to integrated WTW view are published in separate reports. ● The following two HDV configurations have been analysed: ● Rigid truck with 18 tons gross vehicle mass rating (GVMR) designed for use in regional delivery mission (“group 4 vehicle”) ● Tractor-semitrailer combination with 40 tons GVMR designed for use in long haul mission (“group 5 vehicle”) The analysed HDV configurations are either driven with a conventional internal combustion engine (ICE) or an electrified propulsion system (xEV). ICE only configurations include the technologies: ● Direct Injection Compression Ignition (CI) ● Port Injection Positive Ignition (PI) ● LNG High Pressure Direct Injection Compression Ignition (HPDI) For CI engines the fuels Diesel B0, B7 and B100 (FAME) as well as DME, ED95, OME and Paraffinic Diesel were considered. For PI engines CNG and LNG were analysed. The electrified propulsion systems include: ● Hybrid electric vehicle (HEV) ● Battery electric vehicle (BEV) ● Catenary electric vehicle (CEV) ● Hydrogen/Fuel cell (FCEV) All considered vehicle concepts have been analysed for the model years 2016 and 2025, whereby 2016 models are representing the state of the art on the European market for the individual application purpose. Vehicle specifications for 2025 are based on a technology assessment of future improvements. For xEV concepts the it is at the moment not possible to identify typical vehicle configurations as the these systems are currently a new technology under development for HDV. As a consequence xEV vehicle specifications and related results as elaborated in the present study shall been understood as examples for these new technologies. Simulation of vehicles which are driven by an ICE only have been performed with the software Vehicle Energy Consumption Calculation tool (VECTO), the tool which is also used for the CO2 certification of HDV in the EU. Electrified propulsion systems have been simulated with the model PHEM as these propulsion concepts are not covered in the current VECTO version. Figure 1 and Figure 2 give a summary on the results on transport specific figures (i.e. per tonne-kilometre) for energy consumption and TTW CO2-equivalent emissions. The main conclusions on the comparison of different propulsion systems drawn from these results are given in chapter 7 of this report.JRC.C.2-Energy Efficiency and Renewable

Does Work Affect Personality? A Study in Horses

It has been repeatedly hypothesized that job characteristics are related to changes in personality in humans, but often personality models still omit effects of life experience. Demonstrating reciprocal relationships between personality and work remains a challenge though, as in humans, many other influential factors may interfere. This study investigates this relationship by comparing the emotional reactivity of horses that differed only by their type of work. Horses are remarkable animal models to investigate this question as they share with humans working activities and their potential difficulties, such as “interpersonal” conflicts or “suppressed emotions”. An earlier study showed that different types of work could be associated with different chronic behavioural disorders. Here, we hypothesised that type of work would affect horses' personality. Therefore over one hundred adult horses, differing only by their work characteristics were presented standardised behavioural tests. Subjects lived under the same conditions (same housing, same food), were of the same sex (geldings), and mostly one of two breeds, and had not been genetically selected for their current type of work. This is to our knowledge the first time that a direct relationship between type of work and personality traits has been investigated. Our results show that horses from different types of work differ not as much in their overall emotional levels as in the ways they express emotions (i.e. behavioural profile). Extremes were dressage horses, which presented the highest excitation components, and voltige horses, which were the quietest. The horses' type of work was decided by the stall managers, mostly on their jumping abilities, but unconscious choice based on individual behavioural characteristics cannot be totally excluded. Further research would require manipulating type of work. Our results nevertheless agree with reports on humans and suggest that more attention should be given to work characteristics when evaluating personalities

Could Work Be a Source of Behavioural Disorders? A Study in Horses

Stress at work, as shown by a number of human studies, may lead to a variety of negative and durable effects, such as impaired psychological functioning (anxiety, depression…). Horses share with humans this characteristic of working on a daily basis and are submitted then to work stressors related to physical constraints and/or more “psychological” conflicts, such as potential controversial orders from the riders or the requirement to suppress emotions. On another hand, horses may perform abnormal repetitive behaviour (“stereotypies”) in response to adverse life conditions. In the present study, we investigated whether the type of work the horses are used for may have an impact on their tendency to show stereotypic behaviour (and its type) outside work. Observations in their box of 76 horses all living in the same conditions, belonging to one breed and one sex, revealed that the prevalence and types of stereotypies performed strongly depended upon the type of work they were used for. The stereotypies observed involved mostly mouth movements and head tossing/nodding. Work constraints probably added to unfavourable living conditions, favouring the emergence of chronic abnormal behaviours. This is especially remarkable as the 23 hours spent in the box were influenced by the one hour work performed every day. To our knowledge, this is the first evidence of potential effects of work stressors on the emergence of abnormal behaviours in an animal species. It raises an important line of thought on the chronic impact of the work situation on the daily life of individuals

Adult-Young Ratio, a Major Factor Regulating Social Behaviour of Young: A Horse Study

Adults play an important role in regulating the social behaviour of young individuals. However, a few pioneer studies suggest that, more than the mere presence of adults, their proportions in social groups affect the social development of young. Here, we hypothesized that aggression rates and social cohesion were correlated to adult-young ratios. Our biological model was naturally-formed groups of Przewalski horses, Equus f. przewalskii, varying in composition.We investigated the social interactions and spatial relationships of 12 one- and two-year-old Przewalski horses belonging to five families with adult-young ratios (AYR) ranging from 0.67 to 1.33. We found striking variations of aggression rates and spatial relationships related to the adult-young ratio: the lower this ratio, the more the young were aggressive, the more young and adults segregated and the tighter the young bonded to other young.This is the first study demonstrating a correlation between adult-young ratios and aggression rates and social cohesion of young individuals in a naturalistic setting. The increase of aggression and the emergence of social segregation in groups with lower proportions of adults could reflect a related decrease of the influence of adults as regulators of the behaviour of young. This social regulation has both theoretical and practical implications for understanding the modalities of the influence of adults during ontogeny and for recommending optimal settings, as for instance, for schooling or animal group management