Book Review: Active Vision:The Psychology of Looking and Seeing

 

John M. Findlay and Iain D. Gilchrist

            This book has a personal story. It is published by Oxford University Press and I purchased it when we were visiting one of our sons in Oxford a few years ago. It was a special experience to go back last year when he was awarded his MBA.

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   *Pictured: Brendan, Miss Caterina and GJW

This book is about vision, eye movements, and attention – exactly what we evaluate and train – but it is not written by optometrists. It is written by vision scientists based on their research on perceiving our environment and reading. It is also in full agreement with what the philosopher Alva Noe has to say in Action in Perception which was reviewed last week. While I love to share what has been discovered by optometry, support from other disciplines is very satisfying. The following excerpts will let the book speak for itself.

The Active Vision approach presents a dynamic view of the process of seeing, with a particular emphasis on visual attention. However we contend that the regular sampling of the environment with eye movements is the normal process of visual attention. An enormous research effort has been made in recent years directed at understanding covert attention; attending mentally to one location while looking at another. We believe that this balance is wrong and overemphasizes a significant, but subsidiary, process in vision to the neglect of a far more important set of processes. As we hope to show in the course of the book, covert attention acts to supplement overt movements of the eyes, not to substitute for them. (When there are visual problems, covert attention may take precedence over active attention as is sometimes seen in individuals who have autism.)

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We disagree profoundly with the disdain often found amongst cognitive psychologists and others for the study of anything other than ‘pure’ mental activity.

One of the major emphases of the new approach concerns the inhomogeneity of the visual system. We have pointed out that much thinking in passive vision implicitly downplays the role of the fovea. We make the counterargument that the radial organization of the visual system based on the fovea is far from co-incidental but is rather its most fundamental feature. A simple but telling argument considers a hypothetical brain, which provided the same high-resolution as found in the human foveal vision at all locations in the visual field. It has been calculated that such a hypothetical brain would be some hundreds of times larger than our current brain and so would weigh perhaps ten tons. A mobile eye constructed on the principle of the vertebrate eye is not a co-incidence or a luxury but is very probably the only way in which a visual system can combine high-resolution with the ability to monitor the whole field.

Within this framework, attention is a by-product of the action of motor systems.

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