Browsing by Author "Olsen, Mariana Rachel"

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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. Hutchison
Pet 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.
Inducing proactive control using a Stroop cueing paradigm
(Montana State University - Bozeman, College of Letters & Science, 2014) Olsen, Mariana Rachel; Chairperson, Graduate Committee: Keith A. Hutchison
Cognitive control refers to the relative ability to attend to relevant stimuli while ignoring irrelevant stimuli in service of a goal. Braver, Gray, and Burgess (2007) have proposed two complementary forms of control: proactive, which is preparatory in nature, and reactive, which is engaged after a stimulus or imperative event. The ability to use proactive control is often tested using the Stroop task; however, what is usually thought of as evidence for proactive control can be confounded with item-specific effects, sequential effects, and speed-accuracy trade-offs. To remedy this issue, the current study utilized a modified version of the Stroop task to examine the use of proactive control on a trial-by-trial basis. Two experiments tested participants' ability to flexibly engage proactive control in which participants were given 80% predictive EASY or HARD cues indicating whether an upcoming stimulus would be congruent or incongruent, respectively. I hypothesized that participants, especially those high in working memory capacity, would use the HARD cues to engage top-down control to suppress word-reading, leading to a) reduced Stroop interference following HARD cues, b) impaired recall and recognition for neutral words following HARD cues, and c) greater pupil dilation following HARD than EASY cues. In Experiment 1, participants showed reduced Stroop interference for stimuli following HARD relative to EASY cues. This effect was replicated in Experiment 2, with reduced Stroop interference in both reaction times and errors following HARD cues. However, neither recall or pupil dilation differed reliably as a function of cue or WMC. Together, these experiments demonstrate the utility of using a cueing procedure when examining proactive control in the Stroop task. Limitations and future directions in cueing research are discussed.