The relationship between Humphrey Frequency Doubling Technology Visual Field Instrument and reading ability

The purpose of this dissertation was to examine the relationship between magnocellular visual processing, as measured by the Humphrey Frequency Doubling Technology (FDT) Visual Field Instrument, and reading achievement using a convenience sampling of sixth grade students from two suburban school districts. The Humphrey FDT uses new technology that facilitates a quick and reliable assessment of presumed magnocellular visual processing. Some laboratory studies have suggested that a deficit in magnocellular functioning is related to reading disorders. There is presently a debate over the magnoceflular deficit theory of dyslexia as an explanation for poor reading performance. The potential application of this research is the downward extension of the Humphrey FDT as a screening tool for children prior to school entry since it is relatively inexpensive and easy to use. The results from the FDT might allow for the early identification of students with reading disorders and thus allow intervention strategies prior to the onset of psychosocial complications due to magnocellular deficits.;Specific components of this dissertation include: (1) discussion of magnocellular and parvocellular processing, (2) test-retest reliability of the FDT with sixth grade participants, (3) relationship of the FDT to reading achievement, and (4) future use of the FDT. This study found acceptable levels of test-retest reliability for screening purposes. Nevertheless, no significant difference was found between nondisabled readers, readers who possibly have a reading disability, and readers who have a reading disability regarding their magnocellular processing as measured by the Humprhey FDT. This research, therefore, was unable to provide empirical evidence supporting the relationship between the magnocellular deficit theory and reading disability.