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Item Does increased task difficulty reveal individual differences in executive function in the domestic dog?(Montana State University - Bozeman, College of Letters & Science, 2018) Olsen, Mariana Rachel; Chairperson, Graduate Committee: Keith A. HutchisonPet dogs are carnivores that inhabit a largely human-dominated context, in which certain normal canid behaviors (e.g., resource-guarding, barking, mounting) are considered undesirable and even dangerous. Safety and welfare implications of human-dog interaction have recently led researchers to take an interest in canine executive function. Two tasks have become particularly popular in this area of study: the cylinder task and the A-not-B task. Because canine cognition tasks are not typically subjected to the same scrutiny as those used in human research, it is unclear whether these tasks indeed measure what researchers expect them to. Even though they ostensibly measure canine inhibitory control, task performance seldom correlates between the two, and researchers have suggested that they might be too easy to reflect effortful processes. Further complicating the matter are lack of reliability estimates and frequent use of under-powered samples. In this study, I evaluated the reliability and construct validity of the cylinder task and A-not-B task. Across two experiments, I tested modified forms of the cylinder task to make it more difficult and thus more reflective of individual differences in executive function. In Experiment 1, subjects completed the cylinder task under normal conditions and following self-control exertion. In Experiment 2, subjects performed the cylinder task either with or without practice retrieving a treat from an opaque apparatus. Subjects in both experiments performed the A-not-B task with removal of ostensive human cuing. Performance on behavioral tasks was compared to owner-reported measures of impulsivity, inattention, behavioral regulation, responsiveness, and aggression. In Experiment 1, performance was negatively affected by self-control exertion, but only to the degree that dogs exhibited self-control. This suggests that the cylinder task reflects an effortful, limited-capacity process. In Experiment 2, subjects performed worse when practice was omitted, suggesting that cylinder task performance partially reflects the ability to transfer the strategy learned during practice to the test trials. Across both studies, performance during the cylinder task and A-not-B task was uncorrelated. Further, the cylinder task showed high reliability whereas the A-not-B did not. Implications of these results and suggestions for future directions are discussed.Item Investigating the maintenance of unfulfilled goals overtime : do they occupy executive resources?(Montana State University - Bozeman, College of Letters & Science, 2015) Garrison, Katie Elizabeth; Chairperson, Graduate Committee: Ian M. HandleyPsychological research demonstrates that goals can remain active across time until they are fulfilled, even unconsciously and, presumably, passively. Yet, recent research suggests that unfulfilled goals require effort to maintain, drawing upon the limited pool of executive resources and interfering with executive control. If true, the logic follows that unfulfilled goals should compromise executive control initially following goal activation and after a delay. However, another possibility is that the executive control deficits resulting from an unfulfilled goal are due to the initial mobilization of effort required to activate the goal in the first place, and that executive control is only compromised initially following goal activation and not after a delay. To test these competing predictions, participants in two reported experiments received a goal to form impressions of roommates in an upcoming experimental task, or no goal. Next, participants engaged in an unrelated task that required the inhibition of a prepotent response (i.e., executive control). Performance on this task is dependent on the availability of executive resources, as one needs these resources to successfully inhibit a prepotent response. In addition, participants engaged in this task either immediately after goal (or no goal) activation, or after a few-minute pause. The results of both experiments indicate that the impression formation goal had no effect on executive control immediately or after a pause. The proposition that unfulfilled goals occupy executive resources is likely complicated by moderating variables, as a simple yet effective goal manipulation in the current experiments did not compromise executive resources.