This conference was instigated by a combination of factors: The nature of the problem, the wide spread occupational epidemiology reported on eye symptoms and eye fatigue in the workplace, and the organizers' awareness of the complexity of the scientific and clinical bases of knowledge that might be usefully applied. The introduction of new methods into system neurobiology provides new insights into how we receive and process information from the external world, and act upon it. New, non-invasive methods have opened the way to direct observation of the human brain in action. Due particularly to the interaction between the visual and oculomotor requirements involved, several clinical and scientific fields intersect when these issues are considered. To provide clear vision the accommodative and pupillary mechanisms are used. To maintain binocularity, the ver gence oculomotor system, sensitive to fatigue, must attain congruence with accommodative levels. This accommodation-vergence linkage was a focus of our symposium."

This conference was instigated by a combination of factors: The nature of the problem, the wide spread occupational epidemiology reported on eye symptoms and eye fatigue in the workplace, and the organizers' awareness of the complexity of the scientific and clinical bases of knowledge that might be usefully applied. The introduction of new methods into system neurobiology provides new insights into how we receive and process information from the external world, and act upon it. New, non-invasive methods have opened the way to direct observation of the human brain in action. Due particularly to the interaction between the visual and oculomotor requirements involved, several clinical and scientific fields intersect when these issues are considered. To provide clear vision the accommodative and pupillary mechanisms are used. To maintain binocularity, the ver gence oculomotor system, sensitive to fatigue, must attain congruence with accommodative levels. This accommodation-vergence linkage was a focus of our symposium."

To anyone who worked long on the functional organization of living systems, it seems obvious that the central problems arise from a multi plicity of closed loops Simultaneously active in the control of every act. Severally, they may be stable but, combined, they may crack up or break into schizogenetic oscillation. Whatever they are, linear or not, is beside the point, for in either case the same difficulty of analysis arises. Nor does it help our argument that we deal only with formal neurons or those having greater similitude to real ones. This limited Pitts and me, in 1943, to three theorems of Part III of our "Logical Calculus of Idea Immanent in Nervous Activity. " We still seek a transparent terminology in which to discern their properties. In the face of such difficulties it takes great courage to attempt a servo system analysis of the control mechanisms me diating any reflex if one would do this as a good engineer. Walt Whitman says of the "Beginners," "How dear and dreadful they are to the earth - appearing at intervals - How all times mischoose their objects of adulation and reward - And how the same price must still be paid for the same great services " Larry Stark is a beginner. His book must not be mistaken for phys iology - and there is nothing wrong with his physiology."