Robert Fox pursues a program of research on visual perception that embraces, variously, infants, children, normal, mildly mentally retarded, and elderly adults. Major topics are binocular visual phenomenon such as global stereopsis, rivalry and fusion. Related interests are perception of 3D space and global motion. Recently, he discovered profound deficits in visual perception in the mildly retarded. These heretofore unsuspected anomalies provide a new perspective on intelligence and cognitive function.
His interest in issues relevant to cognitive neuroscience dates back to his pioneering investigation of the suppression process intrinsic to binocular rivalry. Using psychophysical methodology, he found that suppression induced a nonselective inhibitory state that functionally uncoupled physical stimulation from phenomenal representation for durations on the order of seconds. That inquiry led to an examination of other binocular phenomena, including stereopsis, which have yielded data contributing to the resolution of specific questions about the operation of binocular vision. In addition, his work has forged conceptual links with higher order perceptual and cognitive variables, thereby contributing to a theoretical framework that unites those variables with fundamental visual mechanisms.
A case in point is the use of rivalry suppression to separate functionally perceptual stages in order to infer the loci of processing sites. This approach foreshadowed the one outlined by Bela Julesz, which he dubbed psychoanatomy, to describe the way similar inferences could be made via random element stereograms. Because these stereograms and their temporal counterparts, kinematograms, do not contain extraneous cues, they have made it possible to widen the inquiry into binocular vision to include animals and nonverbal organisms in general. That feature has enabled Fox and colleagues to examine the ontogenetic development of stereopsis in humans, and it phylogenetic development in animals representing diverse lines of descent. The considerable demands upon neural computation imposed by random element stimuli has also sparked Fox’s current interest in the ability of mildly mentally retarded adults to perceive them correctly. He and his colleagues have found that retarded persons encounter profound difficulty discriminating among random element forms under conditions implying the existence of a neural deficit located at an early precognitive stage of the perceptual system. These results fit well with the growing consensual view that relates the genesis of a wide spectrum of higher order cognitive or intellectual activity to the manipulation of internal representation of perceptual phenomena that have developed early in life through normal commerce with the environment. Fox’s work is supported by grants from NIH.