Clive Wynne - US grants

DESCRIPTION (provided by applicant): The purpose of this study is to test the effects of a major dopaminergic drug of abuse, amphetamine, on time perception and time production under both short- and long-term treatment conditions in pigeons. Drug dependency is associated with increased impulsiveness. This impulsiveness has been linked to changed temporal discounting - drug abusers undervalue the future compared to the present and choose small immediate rewards in preference to larger delayed rewards to a greater degree than do non-abusers. The impulsiveness of habitual drug users may help to maintain their risky drug-taking behavior, as well as placing them in danger of disease and injury through other high-risk activities. One reason why drug users may undervalue future events is because of changes in their perception of time. Most drugs of abuse stimulate the dopamine neurotransmitter system and thus alter the perception and production of arbitrary time intervals. Consequently, drug abuse may have its observed effects on impulsivity by virtue of dopaminergic effects on time perception. Though prior studies have assessed the short-term effects of dopaminergic drugs on the timing of arbitrary intervals no prior attempts have been directed towards examining possible longer-term effects of dopaminergic drugs on time perception and production. Aside from their practical importance the results of these studies will also contribute to an ongoing debate about how dopamine controls timed behavior. Some theorists believe that drugs affect the speed of an 'internal clock.' We believe, however, that there is no internal clock as such, and that drugs influence the perception of time by altering the perceived salience of the events used to delineate time intervals in experiments on timing.

DESCRIPTION (provided by applicant): Tens of millions of children in the United States co-reside with pet dogs. Recent research suggests living or interacting with dogs promotes learning outcomes and has health benefits. Biological mechanisms underlying these processes are largely unknown but may include protective effects on the activity of stress-sensitive biological systems. The neuroendocrine arm of the stress system known as the hypothalamic-pituitary- adrenocortical (HPA) axis may be of particular importance because 1) it influences long-term neural activity and many organ systems, 2) disturbances in it are linked with impaired cognitive and emotional functioning and a range of physical diseases across the lifespan, and 3) its activity is impacted by diverse qualities of human social relationships. Among infants and children, supportive relationships with close family members have a buffering effect on HPA axis activity in response to stress. Along with family members and close friends, pet dogs are known confidantes for children. It is unknown whether pet dogs buffer the HPA response to stress. We propose testing the stress-buffering potential of pet dogs in a standardized laboratory protocol, the Trier Social Stress Test, known to produce reliable stress responses in children and adults. 90 nine-year-old children from dog-owning families will be tested either in the presence of their dog, their parent, or without a support figure. To date there are no studies testing individual differences in the child, pet, or child-pet relationship that impact the degree to which pet dogs confer health benefits (stress-reducing or otherwise) for children. Thus we further aim to examine characteristics that moderate dogs' impact on children's stress responses. We hypothesize that the presence of a pet dog during a laboratory-based social stressor will buffer the child's biological response to the stress test, and that this buffering will be similar to that observed in the presence of a support person - the parent. We further hypothesize that across experimental conditions, the buffering effect will be impacted by the child's temperament and attachment to the dog as well as the dog's sociability and responsiveness to the child's gestures. By characterizing the role of pet ownership and pet presence in the developing biological stress response in children, the results obtained will contribute both to our understanding of stress in children and how it can be buffered, and also to our understanding of how human-animal interaction may have health benefits. Thus the outcome of this project will be a better basis for the burgeoning field of animal interactive therapy. PUBLIC HEALTH RELEVANCE: Dogs are ubiquitous in Western society and are believed to provide social and emotional support to children. The purpose of this study is to investigate the stress-buffering potential of pet dogs for children in order to better characterize the conditions under which dogs may help reduce stress.