The purposes of this research were to: (1) determine the dependence of vernier acuity upon specific spatial frequency channels; (2) determine the effect of stimulus position in the central 2 deg arc upon vernier acuity thresholds; (3) investigate the relationship between binocular, monocular, and dichoptic vernier acuity; (4) evaluate the effect of the subjective task upon vernier acuity thresholds; and, (5) determine the differences between using absolute thresholds and difference thresholds as measures of vernier acuity. / Vernier acuity thresholds were found to be a function of both spatial frequency (0.5-20 cpd) and grating contrast (0.25-0.65). Thresholds were higher with low spatial frequency grating ($<$2 cpd), and the low spatial frequency grating thresholds were most affected by reduced levels of contrast. Vernier acuity mechanisms appear to utilize information over a wide range of spatial frequencies. / Monocular vernier acuity thresholds were found to vary with the stimulus position, with stimulus in the nasal hemifield resulting in lower thresholds than presentation in the temporal hemifield. Binocular vernier acuity was well predicted from the monocular vernier acuity by a probability summation model, suggesting independence between the monocular inputs. / In general, stimulus detection resulted in lower thresholds than stimulus classification (i.e., offset direction), particularly at low spatial frequencies. Difference thresholds were consistently lower than absolute thresholds, and they showed smaller variations with stimulus manipulation than absolute thresholds. / Source: Dissertation Abstracts International, Volume: 49-10, Section: B, page: 4598. / Major Professor: Mark A. Berkley. / Thesis (Ph.D.)--The Florida State University, 1988.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_77872 |
| Contributors | Ryan-Jones, David L., Florida State University |
| Source Sets | Florida State University |
| Language | English |
| Detected Language | English |
| Type | Text |
| Format | 137 p. |
| Rights | On campus use only. |
| Relation | Dissertation Abstracts International |
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