Eyemovements Study On Overt Visuospatial Attention Shifts In Learning Disabilities

In our visual environment, we orient to information that is either salient or interesting. Orienting may involve overt movements of the head, eyes, or body, or covert shifts of attention whereby the head, eyes, or body remain stationary. Overt orienting and covert orienting used to be accepted as independent systems. However, near one decade's development, more and more brain imaging studies have showed that they share the common brain functions. By terms of arising of attention, it can be classified as endogenous attention and exogenous attention. Endogenous attention is summoned by the behavior goals or intentions of observer, whereas exogenous attention is deployed by salient information that appeared at the peripheral location of the observer's visual field. Both overt and covert attention, which changes attentional priorities, may be either automatic, as when we orient to salient information, or effortful, as with voluntary shifts of attention to something of mental interest. Ever since Posner rendered this category in early 80's of last century, endogenous and exogenous visual spatial attention shifts have been the leading and hot field in general psychology. Little attention has been paid to overt attention shifts yet most of studies focused on covert attention shifts despite the fact of that overt visual-spatial attention shifts was more common in daily life. In order to improve the ecological effect of study, the endogenous and exogenous overt visual-spatial attention shifts was the focus, and the differences between normal and learning disabled children under these tasks were highlighted in this thesis.Learning disabilities were groups of special education populations, differing from common learning difficulties or under-achievers, in that they had the normal intelligence but impaired abilities in thinking, language skills, reading, writing, spell, or numerical calculation. It was reported that LD children had attentive difficulties. It was hypothesized that LD children had deficient overt visual-spatial attention shifts because of inefficient use of the cue information and a lack of proper attentive strategies, and this kind of deficiency impaired their ability to operate on more demanding cognitive tasks. Two eyemovements recording experiments were carefully manipulated on LD and normal children in grade 3 and grade 6 of primary school to testify these assumptions.Cognitive cue was employed in experiment 1 to prompt the endogenous overt attention. Eyelink II was used to record the response time, fixation time, fixation points, and fixation location, et al. The statistics analysis showed that normal children of grade 6 had the better endogenous attention control while LD children of grade 6 less efficient. All children of grade 3...