Since childhood, Richard Held was intrigued by the illusions of vision and their motor consequences. This interest motivated a long and prolific professional career as a teacher and research scientist for which Held received many commendations and awards.
After graduating from Stuyvesant High School in New York City, he earned an undergraduate engineering degree from Columbia University and then spent two years in the U.S. Navy. Following discharge, he accepted an invitation to join Wolfgang Koehler at Swarthmore College in the quest for evidence of hypothesized electric brain potentials accompanying moving visual targets.
In joining Koehler, Held returned to his earlier interests and made a commitment to his future career in academia. Two and-one-half-years of research with Koehler confirmed their original hypothesis and the results were then published in Science. These findings were received with little interest on the part of what was to become the neuroscience community (see Vision and Visual/Motor). It was not until recently that Held was told that the Koehler-Held discovery was, in effect, a precursor to the epoch-making findings – discoveries of single cell electrical responses in the visual cortex - of David Hubel and Torsten Wiesel.
Held left Swarthmore and entered Harvard’s Department of Experimental Psychology for graduate training. He had begun experiments with optical prisms while still at Swarthmore and wished to continue that work. However, there the dominant research support was in audition in the Psychoacoustic Laboratory where Georg v. Bekesy and S. Smith Stevens held forth.
Consequently, Held, in youthful optimism, assumed that his prism paradigm could be transferred from vision to audition. The consequent experiments on adaptation to rearranged auditory direction-finding became his PhD thesis (see Auditory Localization). While still at Harvard, Held also did a study of adaptation to the chromatic aberration of optics including that of the eye itself (see Visual Adaptation).
Held’s first faculty appointment was at Brandeis University. There he built a research laboratory and recruited graduate students. Like all research collaborators in Held’s laboratory, their names appear on papers published under their authorships and co-authorships (see Publications List).
Several of these students studied the effects of visual rearrangement and discovered the role of self-produced movement in generating adaptive correction for optically induced error (see Visual Motor Rearrangement).
The prism paradigm became increasingly popular during those years. Some of the findings began to reveal cases where, with enough time of exposure, full and exact correction of prism-induced error was produced by adaptation. Correspondingly, Held noted that accurate coordination is maintained throughout life, despite growth of the body that is a natural form of rearrangement. He concluded that the adaptive process should be capable of compensating for any neonatal errors and might even be necessary for development itself.
This logic called for evidence of the potential role of self-produced movement during the course of development of visual function, beginning as early as possible. It led Held’s group to devise tests of the vision and visuomotor performance of neonates, as well as procedures for controlled rearing first of kittens, then of monkeys (see Animal Models of Visual Development). Similar procedures with human infants came later (see Vision Development).
After ten years at Brandeis, Held was appointed to the faculty at Massachusetts Institute of Technology and joined a newly established group under the leadership of Hans-Lukas Teuber.
It was Teuber who was responsible for conceiving and developing what was, in effect, the first department of neuroscience in the U.S., if not the world. It brought together colleagues and students with common interests in a challenging intellectual environment and provided facilities for a wide range of experiments, both animal and human.
In dealing with human infants, experiments were, of course, limited to non-invasive procedures measuring looking preferences, optokinetic nystagmus, and motor responses, such as reaching for targets. Using these methods, they developed procedures for measuring visual resolution, including grating, vernier, and stereo acuities, and other procedures for assessing binocularity (see Vision Development).
Optical procedures were used to measure refractive error, accommodation, and movements of the eyes. They yielded previously unavailable normative data on the development of basic visual functions (see Optics/Myopia). Resulting methods are being utilized today in clinics to assess effects of pathology on the vision of infants and children and to monitor therapy. They have provided data that reflect the development of the visual nervous system.
Because of their immaturity, testing neonatal animals can prove difficult, if not impossible. Consequently, when exposure to some environmental factor is suspected to be necessary for development, controlled rearing may temporarily eliminate that factor, until normal maturation makes testing feasible. Held’s group used such procedures with kittens and monkeys to demonstrate the role of self-produced movement in development.
The importance of testing newborn human infants is matched by its extreme difficulty. However, a form of naturally controlled rearing is achieved by testing the newly-sighted child immediately following surgery that allows sight to replace congenital blindness. This procedure was enabled by Project Prakash under the leadership of Pawan Sinha.
Many of the outcomes of these tests have, in turn, been correlated with changes known to occur in the developing nervous system of animals and inferred to occur in that of human infants and children.
Held's major concern centered on perceptual-motor processes. His laboratory also engaged in a number of other projects involving colleagues and visitors. One of these projects concerned early pathology identified in the course of studying human development. With the collaboration of specialists, studies were made of early refractive anomalies, such as occlusion by cataract, astigmatism, myopia, optic nerve damage, and more central deficits such as amblyopia.
Myopia became the central focus of a line of research Held engaged in during his appointment as Adjunct Professor at the New England College of Optometry. The study of vection engaged the lab for some time: Watching moving scenes induces a sense of body motion in observers. These effects interact with gravity in determining the sense of orientation in space.
The McCollough Aftereffect demonstrated the dependence of color on the perceived orientation of edges in space. Held's lab demonstrated the obverse - dependence of orientation on color by selective adaptation.
Held later returned to the topic of his Ph.D thesis in collaborative work on auditory localization demonstrating, among other phenomena of auditory space, that of superauditory discriminations.
As in most scientific research, many questions remain to be answered. Held continues to work on the issues that originally intrigued him: What is involved in perception and in interacting with the world. How is this to be understood in terms of neuronal systems?