Israel Abramov - US grants

Colors of objects are often specified by tristimulus colorimetry in some standard colorimetric system. While color-matching allows a color to be reproduced accurately, it does not specify what the color actually looks like. In fact, colorimetric matches will hold under widely varying conditions, while appearance may change drastically. Color-order systems, such as the Munsell, are often used for appearance descriptions but they suffer from several important limitations. A more direct approach is to use hue and saturation scaling, a technique which, when used correctly, has a precision not very different from that of color-matching. The specific aims of this proposal are to refine the procedures of color scaling and to develop methods that will permit its use as a tool with which to study color vision. These scaling methods allow rapid collection of data, which makes it possible to obtain comprehensive findings across large parametric spaces. This is necessary for any detailed modelling of the visual system. The analytical methods will use multidimensional scaling to derive Uniform Appearance Diagrams from which standard discrimination functions may be calculated. These functions will be compared with functions measured by conventional methods. While these scaling methods are known to work with English, it is important to see if they are independent of the specific language used; thus they will also be tested on subjects whose native language is not English. The fully developed scaling techniques will be used to study the complete gamut of color space consisting of stimuli that vary in both wavelength and purity. Finally, the methods will be used for a detailed examination of peripheral color vision under a broad range of conditions. These experiments will provide a base of data about normal visual function and will provide the basis for determining which neural cell types underlie various aspects of color vision.

This award provides funds to The Infant Study Center and Visual Research Lab in the Psychology Department at Brooklyn College to establish an REU-Site which will offer students a research experience which focuses on areas in Experimental and Developmental Psychology, and related areas in the Neurosciences. Together with a colleague from Medgar-Evers College of CUNY, mentors will provide training on many aspects of the visual system. The training program includes laboratory seminars, an active role in a specific research "team", and public presentations of results. The research areas are all heavily computerized and instrumented: (i) Development of infants' abilities to focus their eyes on objects around them (i.e., mechanisms of accommodation and convergence); methods will include quantitative photorefraction. (ii) Brain mechanisms associated with vision. Visual evoked potentials will be recorded to examine the maturation of physiological systems, especially those involving the lateral interactions that are so important for object recognition. (iii) Color vision, particularly the use of scaling techniques to specify color appearance under a variety of viewing conditions, such as changes in retinal positions; results will be related to known variations in anatomy and physiology across the retina.

This award provides funds to The Infant Study Center and Visual Research Lab in the Psychology Department at Brooklyn College to continue a successful REU-SITE which offers students a research experience which focuses on many aspects of the visual system. Together with a colleague from Medgar-Evers College of CUNY, mentors will constitute a REU-Site aimed at students who might be persuaded by their research experience to continue to the doctorate in Experimental and Developmental Psychology, and related areas in the Neurosciences. Both institutions have many women and minority students as well as special programs to attract and guide such students; heavy emphasis will be placed on recruiting among them. The training program includes laboratory seminars, an active role in a specific research "team", and public presentations of results. The research areas are all heavily computerized and instrumented: (i) Development of infants' abilities to focus their eyes on objects around them (i.e., mechanisms of accommodation and convergence); methods will include quantitative photorefraction. (ii) Brain mechanisms associated with vision. Visual evoked potentials will be recorded to examine the maturation of physiological systems, especially those involving the lateral interactions that are so important for object recognition. (iii) Color vision, particularly the use of scaling techniques to specify color appearance under a variety of viewing conditions, such as changes in retinal position; results will be related to known variations in anatomy and physiology across the retina.

This award provides funds to The Infant Study Center and Visual Research Lab in the Psychology Department at Brooklyn College to continue a successful REU-Site which offers students a research experience which focuses on many aspects of the visual system. Together with a colleague from Medgar-Evers College of CUNY, mentors will constitute a REU-Site aimed at students who might be persuaded by their research experience to continue to the doctorate in Experimental and Developmental Psychology, and related areas in the Neurosciences. Both institutions have many women and minority students as well as special programs to attract and guide such students; heavy emphasis will be placed on recruiting among them. The training program includes laboratory seminars, an active role in a specific research "team", and public presentations of results. The research areas, which are all heavily computerized and instrumented, include: (1) Development of infants' abilities to focus their eyes on objects around them (i.e., mechanisms of accommodation and convergence); methods will include quantitative photorefraction. (2) Brain mechanisms associated with vision. Visual evoked potentials will be recorded to examine the maturation of physiological systems, especially those involving the lateral interactions that are so important for object recognition. (3) Color vision, particularly the use of scaling techniques to specify color appearance under a variety of viewing conditions, such as changes in retinal position; results will be related to known variations in anatomy and physiology across the retina. This award contributes to the Foundation's continuing efforts to attract talented students into careers in science through active undergraduate research experiences.

For effective human vision, the brain must integrate the binocular input from the two eyes, and in turn drive the two eyes to move binocularly in appropriate directions. The development of sensory binocularity appears to depend on the ability to align the two eyes to give visual stimulation of corresponding points on the retina of each eye. This alignment is a precursor to development of cells in the visual cortex that are sensitive to retinal disparity, and for stereoscopic vision. This project studies how oculomotor and sensory factors combine to contribute to the development of binocular visual functions during infancy in humans. Models are outlined for possible developmental relationships, and a novel binocular eye-tracking technique will be used to measure human infant eye movements. Data on developing motor binocularity is compared to data on developing sensory binocularity measured by a variety of behavioral and non-invasive tests, to see how sensory and motor factors are combined. Results from this study will be important to visual science, and also to developmental human research and to human performance analysis, with further likely importance to understanding disorders in binocular vision. ***