Sustained visual attention at different retinal eccentricities and its significance for the development of the preferred retinal locus

[摘要] The ability to deploy visual attention within the visual field varies among different angular positions at equal eccentricities. The selection of the preferred retinal locus of fixation (PRL) is influenced by the high ability to deploy visual attention to a discrete location within the visual field. Most of the maculopathies that lead to PRL development are progressive and as a consequence, PRLs are constantly relocated. A tendency to locate the PRL on the same meridian has been described. Their constant relocation of PRL on the same meridian might be also governed by attentional mechanisms. Thus, this study investigates the variations of sustained visual attention at different eccentricities of the visual field. Four normally sighted subjects participated in the study. Their sustained attention was measured at three different eccentricities of the visual field. The three eccentricities measured were 3.5°, 5° and 6.8° of visual angle. In each measurement, subjects had to report the orientation of a Snellen E presented on a previously cued location. Eight discrete locations on the visual field with a step size of 45° were tested. The results showed a preservation of shape of the attentional performance fields across the different retinal eccentricities. The absence of variations on the shape of the performance fields supports a link between sustained attention and the PRL along the same visual field meridian. These results might contribute to the development of new therapies of progressive central maculopathies.

[学科分类] 眼科学