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  HOMEPAGE (continued) of VISION CONCEPTS
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PROCESSES IN BIOLOGICAL VISION

by JAMES T. FULTON


CONTENTS

This Theory defines six distinct stages in the visual process,


0. Genesis and metabolic support
1. Signal Generation
2. Signal Manipulation (in the retina)
3. Signal Projection
4. Signal Manipulation and Perception (in the cortex)
5. Oculomotor feedback servomechanisms

The unusual sequence is designed to maintain continuity with previous work in the literature where a zone 1 has been associated with photodetection and a zone 2 has been associated with signal computation. It is desirable to build on such earlier notation to avoid unnecessary confusion.

Stage 0 (zero) has been added because of its critical role in the operation of the visual system and the understanding of its transient and failure modes. Stages 3 and 4 are expansions of the previous zone 2 required to interpret a variety of asymmetrical features of the system.

Stage 5 is necessary to incorporate the servomechanisms that are critical to the operation of the visual system of higher chordates. This stage involves servo-loops that incorporate elements of the previous stages. From that perspective, stage 5 is an overlay incorporating parts of the previous stages. The closed loop servomechanism that is created is absolutely critical to the understanding of the overall visual system. It is stage 5 that that generates the signal known as tremor. This tremor converts the basic visual system from a change detector (as in many lower animals) to an imager (as found in man and many higher animals). Stage 5 also introduces several critical signals into the overall system related to the vestibularly subsystem.

The Theory introduces a number of concepts that are well developed in other scientific disciplines but have not previously been recognized in the field of vision. The result is a completely new theoretical foundation of the process of vision. The Theory shows that the neural process is completely electrolytic in character and highly dependent on the properties of liquid crystalline materials. It also defines the actual structure of the photosensitive material of the retina for the first time and compares the actual theoretical spectral properties of the four chromatic absorbers of vision with data from direct measurement. It also develops the detailed signaling properties of the neuron and shows the specific role of the glutamates is that of an electrostenolytic power source unrelated to the signaling function.

Based on these new concepts, the Theory is illustrated via a series of comprehensive block, schematic and circuit diagrams. Two parallel signal paths that extend from the cornea of the eye to the perceptual region of the cortex are diagramed in detail. In a specific case, the complete signal path is diagramed, down to the specific circuit level. This path is along the afferent neural path from the cornea to the midbrain and then back to the oculomotor muscles of the eye along the efferent neural path. It is shown that this path (mentioned above) constitutes a complete loop of a servomechanism system.

The Theory and models together provide details of the operation of the visual system of animals not discussed elsewhere in the literature. The presentation of the Theory is grouped into five parts:

PART A: Environment and Physiology of Visiontable of contentsread Intro.down load
PART B: Bioelectochemistry of the Photoreceptortable of contentsread Intro.down load
PART C: Electrochemistry of the Visual Neuronstable of contentsread Intro.down load
PART D: Detailed Modeling of the Overall Visual Processtable of contentsread Intro. down load
PART E: Overall Performance of the Visual Systemtable of contentsread Intro.down load

and a set of APPENDICES. These appendices contain short technical vignettes (such as on color constancy), longer studies (such as the visual architecture of Limulus), and a series of suggested thesis topics for upper level students.

A Synopsis of the overall work is also available. The Synopsis, by its nature, is not able to defend the positions taken. This is done exhaustively in the main text.

A Preface is also provided. It attempts to codify some of the conceptual and philosophical considerations leading to this work.

A new expanded tabulation of the Characteristics of the Standardized Human Eye and the Characteristics of the Fundamental Neuron are also presented. Finally, a new set of graphs describing the overall performance of the Human Eye are also presented.

MISCELLANEOUS

Where possible, terminology consistent with earlier investigators is preserved. However, in many cases, previously held concepts and hypotheses are discarded in favor of new more precise concepts. In other cases, the old concepts are shown to be more limited in their applicability than previously suggested. A large GLOSSARY is provided summarizing the terminology used in this work and the field of vision.

Numbers in square brackets appearing on this site are references to the paragraphs of the book, "Processes in Animal Vision". As individual Chapters of the book "PROCESSES IN BIOLOGICAL VISION" become editorially acceptable, they are made available here as Portable Document Files (.pdf)

Most other theories of vision, including many of the less comprehensive ones, are reviewed in Chapter 19 of the above material. To minimize controversy, This Chapter is available from the Author upon request.

Preparation of this work by a small group has become a massive undertaking. The author would appreciate any editorial comments, questions or clarifications from interested readers prior to the formal publication of the book. Such comments can be provided using the attached FORM.

The entire work is copyrighted and includes trademarked terms. For permission to reproduce parts of this work, and other information, please see the CITATIONS page.

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