Research is to be conducted on the visual mechanisms by which the human observer resolves fine details and accurately localizes objects in two and three dimensions. The retinal components of these abilities will be analyzed, using optical and psychophysical techniques, by distinguishing between the limits set by the discrete nature of the mosaic of retinal receptors, by the sensitivity to intensity differences that can be detected in small adjacent retinal locations, and by the interaction between retinal neural entities. Identification of Snellen visual acuity letters and stereoscopic vision require, in addition, the elaboration and relative localization of individual features, and these are functions of the cortex. The interest is in the interaction of separate features and the development of the visual attributes of two-dimensional position and three-dimensional depth. The long-term goal is twofold: (1) to specify rigorously the ultimate performance characteristics of the human visual system and to delimit the range of possible neural circuits that may serve as their substrate, and (2) to gain insight into the optical and neural processes subserving visual acuity, hyperacuity and stereoscopic localization that will aid in the differential diagnosis of patients with reduced acuity and the development of tests of etiological and prognostic value.
| Westheimer, G (1991) Visual discrimination of fractal borders. Proc Biol Sci 243:215-9 |
| Bennett, R G; Westheimer, G (1991) The effect of training on visual alignment discrimination and grating resolution. Percept Psychophys 49:541-6 |
| Westheimer, G (1991) Sharpness discrimination for foveal targets. J Opt Soc Am A 8:681-5 |
| Westheimer, G (1990) Simultaneous orientation contrast for lines in the human fovea. Vision Res 30:1913-21 |
| Westheimer, G; Pettet, M W (1990) Contrast and duration of exposure differentially affect vernier and stereoscopic acuity. Proc Biol Sci 241:42-6 |
| Wehrhahn, C; Westheimer, G; Abulencia, A (1990) Binocular summation in temporal-order detection. J Opt Soc Am A 7:731-2 |
| Westheimer, G (1990) The grain of visual space. Cold Spring Harb Symp Quant Biol 55:759-63 |
| Wehrhahn, C; Westheimer, G (1990) How vernier acuity depends on contrast. Exp Brain Res 80:618-20 |
