Visual acuity and foveal cone density in the retina of the aged rhesus monkey.

The specific aims of this study were to examine age differences in visual acuity among young adult (5 years), middle aged (12 years) and aged (22 years) rhesus monkeys in relation to foveal cone density in the diurnal duplex retina. Classically, acuity has been defined as the reciprocal of the least resolvable detail measured in minutes of visual angle. The minimum separable binocular acuity mean of the young adult group was 0.

Age differences in short-term memory and cell loss in the cortex of the rat.

Studies with human and animal subjects have indicated age declines in short-term memory and cell loss in the cortex. Cell loss has been estamated by descriptive nonautomated methods. Declines in short-term memory may be related to reduced learning, movtivation, motor capacity, or some combination of these factors.