RESUMO
Assistance dogs for people with Posttraumatic Stress Disorder (PTSD) support their handlers by performing tasks that are supposed to mitigate the effects of their mental disability. This study examined the Quality of Life (QoL) of PTSD-assistance dogs' handlers in Austria and Germany using a qualitative online questionnaire based on the Capability Approach. To correspondingly explore whether the involved assistance dogs experience distress triggered by their daily schedules, we measured their salivary cortisol values. These were compared to the cortisol levels of companion dogs without special tasks, as well as diabetic-signal dogs that have a similar workload. Our results showed that people suffering from PTSD-symptoms can improve their QoL with the aid of their assistance dog. However, being accompanied by an assistance dog creates new social barriers. Surprisingly, we found significantly lower salivary cortisol levels in PTSD-assistance dogs compared to the control groups. We conclude that a positive relationship between PTSD-assistance dogs and their handlers can reduce stress on both sides, and that training well tuned to the requirements of an assistance dog can prevent stress in their daily lives.
RESUMO
The extent to which dogs (Canis familiaris) as a domesticated species understand human intentions is still a matter of debate. The unwilling-unable paradigm has been developed to examine whether nonhuman animals are sensitive to intentions underlying human actions. In this paradigm, subjects tended to wait longer in the testing area when presented with a human that appeared willing but unable to transfer food to them compared to an unwilling (teasing) human. In the present study, we conducted the unwilling-unable paradigm with dogs using a detailed behavioural analysis based on machine-learning driven three-dimensional tracking. Throughout two preregistered experiments, we found evidence, in line with our prediction, that dogs reacted more impatiently to actions signalling unwillingness to transfer food rather than inability. These differences were consistent through two different samples of pet dogs (total n = 96) and they were evident also in the machine-learning generated three-dimensional tracking data. Our results therefore provide robust evidence that dogs distinguish between similar actions (leading to the same outcome) associated with different intentions. However, their reactions did not lead to any measurable preference for one experimenter over the other in a subsequent transfer phase. We discuss different cognitive mechanisms that might underlie dogs' performance in this paradigm.
