Biomedical subjects
Publications and source records attributed to A Bazzeo.
Two basic phenomenal properties of an achromatic transparent surface have so far been reported in the literature, namely, density and lightness. This paper provides experimental support for a new phenomenal variable, the visual thickness of a transparent surface. The more transparent is a surface, the less thick it appears.
Orientation sensitivity in the peripheral visual field has been tested in two tasks: (a) setting horizontal the orientation of a grating at various retinal eccentricities, and (b) matching the orientation of a peripherally viewed grating as close as possible to an oblique reference viewed foveally. Both performances fall off with increasing retinal eccentricity. Magnification of the stimulus optimizes peripheral performance. Peripheral performance, optimized by magnification, varies with retinal eccentricity. It approaches, but does not reach, the foveal value (tested by the same method) at 10 deg of eccentricity, and is much lower at 20 and 30 deg of eccentricity.
The aim of the present research was to study illusory dilatation of surfaces isolating some factors contributing to this phenomenon. A series of displays (8.5 cm x 8.5 cm) was prepared: a white square card and five square cards with a uniform pattern of black dots, increasing gradually. The displays were presented to two different groups of subjects, according to the method of paired comparisons and according to the method of limits (under conditions of reduced viewing) respectively. The subjects were asked to evaluate the relative magnitude of the displays. The textured cards significantly differed from the white standard and also among themselves. Up to a threshold, as the dots increase, the surfaces expand as well.