104 research outputs found

    The Jesuits and the Mohammedans.

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    Domestic dogs' (Canis familiaris) understanding of Projected Video Images of a Human Demonstrator in an Object-choice Task

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    Presenting animals with artificial visual stimuli is a key element of many recent behavioral experiments largely because images are easier to control and manipulate than live demonstrations. Determining how animals process images is crucial for being able to correctly interpret subjects' reactions toward these stimuli. In this study, we aimed to use the framework proposed by Fagot etal. (2010) Proc. Natl. Acad. Sci. USA 107, 519 to classify how dogs perceive life-sized projected videos. First, we tested whether dogs can use pre-recorded and hence non-interactive, video footage of a human to locate a hidden reward in a three-way choice task. Secondly, we investigated whether dogs solve this task by means of referential understanding. To achieve this, we separated the location of the video projection from the location where dogs had to search for the hidden reward. Our results confirmed that dogs can reliably use pre-recorded videos of a human as a source of information when the demonstration and the hiding locations are in the same room. However, they did not find the hidden object above the chance level when the hiding locations were in a separate room. Still, further analysis found a positive connection between the attention paid to the projection and the success rate of dogs. This finding suggests that the factor limiting dogs' performance was their attention and that with further training they might be able to master tasks involving referential understanding

    Playful activity post-learning improves training performance in Labrador Retriever dogs (Canis lupus familiaris)

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    Situations that are emotional and arousing have an effect on cognitive performance. It is thought that beta adrenergic activation and the release of stress hormones enhance memory consolidation and lead to an increase in memorability of emotional events. This beneficial effect has been shown in humans, non-human primates and rodents. Techniqueswhich could enhancememory for learning specific taskswould be highly valuable, especially in dogs, which are extensively trained to aid humans. A pseudo-randomized, counterbalanced, between subject study designs was utilised and 16 Labrador Retrievers ranging from 1 to 9 years of agewere trained in a 2-choice discrimination paradigm. After task acquisition, either a playful activity intervention (N= 8) or a resting period (N= 8) took place, lasting for 30 min. A range of factors including age, sex, training experience and trials to criterion on each day was subjected to a multiple factor/covariate General Linear Model analysis. The results show that playful activity post-learning improved training performance evidenced by fewer trials needed to re-learn the task 24 h after initial acquisition (playful activity group: mean number of trials 26, SD 6; resting group: mean number of trials 43, SD 19, effect size 1.2). Average heart rate, as a measure of arousal, during the interventionwas significantly higher in the playful activity group (143 beats/min, SD 16) versus the resting group (86 beats/min, SD 19, P b 0.001). Salivary cortisol did not significantly differ between groups during training, however a significant decrease (T:−4.1 P b 0.01) was seen after the playful activity. To our knowledge this is the first evidence that posttraining activity may influence training performance in dogs

    Handler beliefs affect scent detection dog outcomes

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    Our aim was to evaluate how human beliefs affect working dog outcomes in an applied environment. We asked whether beliefs of scent detection dog handlers affect team performance and evaluated relative importance of human versus dog influences on handlers’ beliefs. Eighteen drug and/or explosive detection dog/handler teams each completed two sets of four brief search scenarios (conditions). Handlers were falsely told that two conditions contained a paper marking scent location (human influence). Two conditions contained decoy scents (food/toy) to encourage dog interest in a false location (dog influence). Conditions were (1) control; (2) paper marker; (3) decoy scent; and (4) paper marker at decoy scent. No conditions contained drug or explosive scent; any alerting response was incorrect. A repeated measures analysis of variance was used with search condition as the independent variable and number of alerts as the dependent variable. Additional nonparametric tests compared human and dog influence. There were 225 incorrect responses, with no differences in mean responses across conditions. Response patterns differed by condition. There were more correct (no alert responses) searches in conditions without markers. Within marked conditions, handlers reported that dogs alerted more at marked locations than other locations. Handlers’ beliefs that scent was present potentiated handler identification of detection dog alerts. Human more than dog influences affected alert locations. This confirms that handler beliefs affect outcomes of scent detection dog deployments

    Spruch

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    Henriette FĂŒrth

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