Walter L. Makous - US grants

The broadest objective is to understand the visual system and how it works, so that pathologies can be better detected, understood, prevented, and treated. Psychophysical techniques are used because of their non-invasiveness; and the observations are based mainly on thresholds and similar measures, so as to minimize the assumptions necessary to draw conclusions about the processing and transmission of information by the visual system. The experiments are intended to describe the operations performed by the visual system on the information it receives, and to constrain admissable representations of the sequences of such operations. The operations studied include transformations of stimulus intensity, attenuation of spatial and temporal information, convergence of color signals into the spatial mechanisms, and processing of stereoscopic and moving images.

The Center for Visual Science is a multidisciplinary center that provides advanced research facilities and specialized instruction for graduate students, postdoctoral researchers, and faculty whose work involves visual science although their disciplines are diverse. Members of the Center have their primary appointments in a variety of departments, including anatomy, brain research, electrical engineering, ophthalmology, optics, physiology, and psychology. This is an application for support of resources and facilities that would enhance the quality and quantity of research at the Center in a way that is not possible through other mechanisms of support.

The purpose of this grant is to obtain a state-of-the-art system for recording horizontal and vertical eye position, for recording the accommodative state of the lens of the eye, and for stabilizing the image of a visual stimulus on the retina. This integrated recording system, manufactured by SRI International, is unique among currently available systems in providing extremely high recording accuracy and low noise without rigid head restraint and with no attachments to the subject's eye or head. As a result, data can be obtained from a wide variety of subjects, including patients who are undergoing evaluation and treatment for oculomotor anomalies. Although the cost of the apparatus makes it difficult to justify for any individual investigator, it will significantly enhance the research of each by permitting observations and experiments not possible without it, and by improving the quality of observations that would otherwise be made. As a shared resource, the system will be used by a major user group of six investigators holding R01 grants from NIH. Each investigator has detailed a plan of research that enhances or extends their research projects. These include the following specific aims: (a) to measure transfer functions for the distal visual system with compensation for the effects of eye movements; (b) to examine the accuracy and stimulus-dependent limitations on the programming of saccadic and vergence eye movements; (c) to determine if eye movements and variations in stimulus fixation affect the components of the averaged visual evoked potential; (d) to study the processes of light adaptation and the perception of visual direction; (e) to examine in detail the characteristics of oculomotor control in patients with various ocular disorders; and (f) to record fixations of text as a measure of word recognition and lexical influence on the parsing of sentences. In addition to these projects outlined by the major user group, the SRI system will attract investigators from other departments in the University (e.g., Computer Science) and from other Universities in the Rochester area (e.g., Cornell).

biomedical equipment; vision; biomedical facility;