Motion Vision: Computational, Neural and Ecological Constraints

edited by J.M.Zanker & J.Zeil,

Springer-Verlag, Berlin, 2001.

DM 169,- (397 pages)

ISBN 3 540 65166 7

How is information about the environment recovered from visual input? This problem can be approached from a range of directions. One strategy is to identify and study the neural substrates of vision: "what's in the head". Such studies typically use simple stimuli to characterize the response properties of cells along the visual pathways. This neural approach assumes that an understanding of the visual system's responses to simple stimuli will generalize to more complex visual environments. A complementary strategy is to analyze the characteristics of the visual environments themselves: "what the head is in". This ecological approach emphasizes that visual systems have evolved in specific contexts under selective pressure to enable certain behavioural tasks. How these sources of knowledge can be combined is a major theme of this book, leading the editors to talk of "a paradigm shift from laboratory-based investigations of visual systems to their analysis in the real world". The value of such a shift is illustrated most clearly in a lively debate on the neural coding of motion in the fly visual system. When the information contained in trains of spikes at various time scales is considered in terms of the relevance of those time scales to the behaviour of the fly, the question of how to interpret the "neural code" becomes inextricably linked to visual ecology.

The section on neural coding is one of six. The book's organisation into a series of keynote papers each followed by two or three companion articles gives windows onto a range of current debates in visual motion detection, showcasing its position as "one of the most active areas in systems neuroscience today"(1). Many of the contributions come from top-flight researchers, ensuring that the views expressed reflect current thinking, while the peer commentaries help maintain balance. The section on the biological basis of local motion detection is followed by discussions of how complex signal distributions can be segmented and used to estimate self-motion, leading into a section devoted to the use of visual motion for the control of eye movements. The discussion of neural coding then gives way to a consideration of motion in natural environments. The range of techniques employed to study vision is matched by the diversity of species studied, from insects to humans, reinforcing the impression that this book is a truly multidisciplinary enterprise. As such it will be of interest to a broad cross-section of vision researchers and neuroscientists.

A review of this book would not be complete without a comment on its cover illustration based on a piece of Australian aboriginal art, "Bush Berries" by Josie Petrick Kemarre. This is doubly apt because the book originated from a workshop held in the Australian capital and the illustration looks remarkably like an image of the retinal cone mosaic.

References

(1) Borst, A. (2000) Models of motion detection. Nature Neuroscience 3, 1168.