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This thesis investigates sensorimotor adaptive mechanisms that maintain the accuracy of goal-directed saccades in amblyopia, a developmental disorder characterized by impairment of spatiotemporal visual processing. Saccadic adaptation was induced by displacing the visual target toward initial fixation during the saccade. Eleven visually normal controls and seven patients with amblyopia were tested binocularly and monocularly with the amblyopic and fellow eye (non-dominant and dominant eye in controls) in three separate sessions. Patients with amblyopia exhibited reduced adaptation of saccadic gain compared to controls when viewing with the amblyopic eye and binocularly. Initiation of saccades was also delayed in patients when viewing with the amblyopic eye. It is proposed that the adaptive ability to modify the initial saccadic motor commands for maintaining short-term saccadic accuracy is impaired in amblyopia due to imprecise error signals. Moreover, this thesis reaffirms the notion that the error signals driving saccadic adaptation are visual in nature.

This thesis investigates sensorimotor adaptive mechanisms that maintain the accuracy of goal-directed saccades in amblyopia, a developmental disorder characterized by impairment of spatiotemporal visual processing. Saccadic adaptation was induced by displacing the visual target toward initial fixation during the saccade. Eleven visually normal controls and seven patients with amblyopia were tested binocularly and monocularly with the amblyopic and fellow eye (non-dominant and dominant eye in controls) in three separate sessions. Patients with amblyopia exhibited reduced adaptation of saccadic gain compared to controls when viewing with the amblyopic eye and binocularly. Initiation of saccades was also delayed in patients when viewing with the amblyopic eye. It is proposed that the adaptive ability to modify the initial saccadic motor commands for maintaining short-term saccadic accuracy is impaired in amblyopia due to imprecise error signals. Moreover, this thesis reaffirms the notion that the error signals driving saccadic adaptation are visual in nature.

Being able to predict the goal of other people’s actions is an important aspect of our daily lives. This ability allows us to interact timely with others and adjust our behaviour appropriately. The general aim of the present thesis was to explore which processes best explain our ability to predict other people’s action goals during development. There are different theories concerning this ability. Some stress the fact that observation of others actions activate the same areas of the brain involved in our own action production, this way helping us to understand what they are doing. Other theories suggest that we understand actions independently of our own motor proficiency. For example, the ability to predict other peoples’ action goals could be based on visual experience seeing others actions acquired trough time or on the assumption that actions will be performed in a rational way. The studies included in this thesis use eye tracking to study infants’ and adults’ action prediction during observation of goal directed actions. Prediction is operationalized as predictive gaze shifts to the goal of the action. Study I showed that infants are sensitive to the functionality of hand configuration and predict the goal of reaching actions but not moving fists. Fourteen-month-olds also looked earlier to the goal of reaching actions when the goal was to contain rather than displace, indicating that the overarching goal (contain/displace) impact the ability to predict local action goals, in this case the goal of the initial reaching action. Study II demonstrated that 6-month-olds, an age when infants have not yet started placing objects into containers, did not look to the container ahead of time when observing another person placing objects into containers. They did, however, look to the container ahead of time when a ball was moving on its own. The results thus indicate that different processes might be used to predict human actions and other events. Study III showed that 8-month-old infants in China looked to the mouth of an actor eating with chopsticks ahead of time but not when the actor was eating with a spoon. Swedish infants on the other hand looked predictively to the mouth when the actor was eating with a spoon but not with chopsticks. This study demonstrates that prediction of others’ goal directed actions is not simply based on own motor ability (as assumed in Study I and II) but rather on a combination of visual/cultural experience and own motor ability. The results of these studies suggest that both own motor proficiency as well as visual experience with observing similar actions is necessary for our ability to predict other people’s action goals. These results are discusses in the light of a newer account of the mirror neuron system taking both statistical regularities in the environment and own motor capabilities into account.

Thesis (Ph. D.)--University of Hong Kong, 2008. / Also available in print.

Thesis (M.A.)--York University, 2006. Graduate Programme in Education. / Typescript. Includes bibliographical references (leaves 77-84). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://proquest.umi.com/pqdweb?index=0&did=1240706441&SrchMode=1&sid=8&Fmt=2&VInst=PROD&VType=PQD&RQT=309&VName=PQD&TS=1195584865&clientId=5220

Thesis (M.S.)--University of Adelaide, Dept. of Surgery, 2004. / "December 2003" Bibliography: leaves 82-99.

Thesis (Ph.D.)--University of Adelaide, School of History and Politics, Discipline of Politics, 2004. / Title from opening screen; viewed 19 May 2005. "August 2004." Includes bibliographical references. Also available in print format.

Thesis (Ph.D.)--University of Adelaide, School of History and Politics, Discipline of Politics, 2004. / "August 2004." Includes bibliographical references (leaves 322-345). Also available electronically via the Australian Digital Theses Program.

Thesis (M.F.A.)--Rochester Institute of Technology, 1992. / Typescript. Includes bibliographical references (leaf 25).