http://hdl.handle.net/1803/213 Sun, 26 May 2013 09:35:40 GMT 2013-05-26T09:35:40Z http://hdl.handle.net/1803/5272 Title: Changes in Motor Performance When Throwing a Ball With and Without Visual Feedback Authors: Khuu, Ngoc-Thoa Abstract: This study explored the roles that vision and proprioception play in learning while throw a ball repeatedly to a fixed location. In two experiments, participants threw a baseball to a target 12 meters away while wearing sound-cancelling headphones to block out auditory feedback. In Experiment 1 participants could freely see the target, but as soon as the ball left their hands, their vision of the ball’s flight and landing was occluded by liquid crystal goggles. Measurements of the ball’s distance of travel along the ground and variability of landing locations were recorded to observe participants’ throwing accuracy and consistency across 100 trials. Results show that participants almost always threw short. The throws improved in consistency for the first half of the trials, showing that people can use proprioceptive feedback to improve the consistency of their motor performance. Experiment 2 was similar to Experiment1, except half of the participants could see the ball’s flight trajectory. Both groups started out throwing short of the target, but the group with visual feedback threw increasingly closer to the target across the 30 repeated trials. Both groups improved their throwing consistency. Kinematic analysis showed that people depended on the ball’s initial velocity rather than the release angle to regulate the distance the ball traveled. Description: Mentor: Dr. John Rieser Mon, 01 Apr 2013 05:00:00 GMT http://hdl.handle.net/1803/5272 2013-04-01T05:00:00Z http://hdl.handle.net/1803/5271 Title: Effects of Dopamine on Reward Learning in Parkinson’s Patients with Impulse Control Disorders Authors: Qualls, Lydia Abstract: This study investigated how dopamine agonist medication differentially affects reward learning in Parkinson’s patients with and without Impulse Control Disorders (ICDs). We tested 16 patients (8 female, 5 with ICDs, mean age = 62.1) on and off of their dopamine agonist medication using a dynamic foraging task with probability reversals. We hypothesized that patients with ICDs, but not patients without ICDs, would have worse task performance on medication than off medication. Paired samples t-tests confirmed our hypothesis – that task performance was significantly worse on medication than off for ICD patients [t(4) = 2.86, p = .046], but not for non-ICD patients [t(10) = 1.67, p = .126]. This suggests that ICD patients are more vulnerable to medication effects that cause aberrant reward learning, which could be the basis of their impulse control behaviors. Tue, 01 Jan 2013 06:00:00 GMT http://hdl.handle.net/1803/5271 2013-01-01T06:00:00Z http://hdl.handle.net/1803/5093 Title: Effects of Frequency and Regularity on New Learning in Preference Readers Authors: Wise, Jessica R. Abstract: Learning to read English requires both knowledge of grapheme-phoneme (GP) rules and rapid recognition for familiar words, which can be mediated by whole-word (WW) mappings. Previous research has suggested that readers differ in their preferences for GP vs. WW strategies of word reading. In an artificial script training study with literate adults, we tested whether preference learners are affected by aspects of the learning demands relevant to English - GP regularity and word frequency. WW preference learners suffered higher costs when reading irregular words, but showed no frequency effects. Further, WW preference learners were more likely to apply GP rules to regular words. These findings suggest that preference may be a measure of ability to use GP strategy appropriately. Sun, 01 Apr 2012 05:00:00 GMT http://hdl.handle.net/1803/5093 2012-04-01T05:00:00Z http://hdl.handle.net/1803/4830 Title: Family Literacy across Three Generations of Undergraduate Students in Africa and the United States: Relation of Family Literacy Experiences on the Grade Point Averages of Undergraduate Students at the University of Botswana, University of Pretoria in South Africa, and Vanderbilt University in the United States Authors: Nanjee, Naveed Abstract: The aim of this study was to describe literacy across three generations of undergraduate students (the students, their parents, and their grandparents) in Southern African (at the University of Pretoria and at the University of Botswana) and in the United States (Vanderbilt University). And, in addition to the main aim, there was an investigation of possible causal relationships that connect the literacy experiences that the undergraduates reported having experienced in the home before the age of five years. The results show strikingly different patterns of family literacy across the three generations: none of the University of Botswana students’ grandparents could read, fewer than half could read at the University of Pretoria, and all could read at Vanderbilt; fewer than half of the University of Botswana parents could read, more than 70% of the University of Pretoria parents could read; all of the Vanderbilt parents could read, and all of the undergraduate students could read. Series of analyses of variance and t-tests were conducted to investigate influences over the college students’ grade point averages, probing the effects of family literacy, reading opportunities in the home, and experiences with story and picture books as young children. Again, the significant findings varied across students from the three universities. For University of Botswana students, there was only one statistically significant relationship, namely, their access to picture books when they were young children. For University of Pretoria students, there were many statistically significant relationships that connected mother and grandfather literacy as well as numbers of adult books and children’s books to university GPA. And as for Vanderbilt students, there was little variability in the data, since all students reported to have literate parents and grandparents, many adult books in the home, and many children’s books in the home. Description: Supervised by John J. Rieser. Tue, 19 Jul 2011 05:00:00 GMT http://hdl.handle.net/1803/4830 2011-07-19T05:00:00Z