This is a book about how we see: the environment around us (its surfaces, their layout, and their colors and textures); where we are in the environment; whether or not we are moving and, if we are, where we are going; what things are good for; how to do things (to thread a needle or drive an automobile); or why things look as they do.The basic assumption is that vision depends on the eye which is connected to the brain. The (...) author suggests that natural vision depends on the eyes in the head on a body supported by the ground, the brain being only the central organ of a complete visual system. When no constraints are put on the visual system, people look around, walk up to something interesting and move around it so as to see it from all sides, and go from one vista to another. That is natural vision—and what this book is about. (shrink)

Describes the various senses as sensory systems that are attuned to the environment. Develops the notion of rich sensory information that specifies the distal environment. Includes a discussion of affordances.

Degeneracy is a poorly understood process, essential to natural selection. In the 18th and 19th centuries, the concept of degeneracy was commandeered by the colonial imagination. A rigid understanding of species, race, and culture grew to dominate the normative thinking that persisted well into the burgeoning new industrial age. A 20th-century reconfiguration of the concept by George Gamow highlighted a form of intraorganismic variation that is still underexplored. Degeneracy exists in a population of variants where structurally different components perform a (...) similar, but not necessarily identical, function with respect to context. The presence of degeneracy increases a system’s complexity and robustness against perturbations. The loss of a genetic component in biological systems, for example, can be compensated by redundant elements , or by degenerate elements . A historical survey of the use of the term “degeneracy” reveals how and why the processes it once designated, and the mechanisms it now represents, have largely escaped the purview of contemporary science. Despite confusion and general oversight, degeneracy has been characterized by select researchers at the molecular, genetic, and neuronal levels. The concept is a potent analytical tool to understand selection, variation, and transmission. (shrink)