Non-Verbal Communication ed. by R. A. Hinde (review)

Books 77 how these 'kinesie' elements are valuable in conveying intended meaning in the case of ambiguous strings of words. It seems to me that these elements add more information to the words and small phrases in speech and so render meaning lessdependent on context. D. G. Hays provides a chapter on the representation of meaning in natural language. It is a good introduction, but rather narrow, and for a broader coverage see the survey by David J. Mishelevitch (Computer Based Semantic Analyses , J. Control and In! Sciences 1, 267 (No.3, 1972)). Work in this field may have applications to visual art, for certainly there is a function of the brain that relates the visual and the verbal (see Chapter 8 on brain lesions and their effects). It might be feasible to use the same semantic structures to describe something of the visual and the verbal. Use of syntactic structures to represent the visual is an attractive idea, for a good deal is known about them, however only limited success has been forthcoming. After reading these chapters, one could refer to Satosi Watanabe (Ungrammatical Grammar in Pattern Recognition, in Pattern Recognition, Vol. 3 (Oxford: Pergamon Press, 1971) p. 385) for a very good discussion of the appropriateness of phrase structure syntax as a model for the visual. Scientists are increasingly able to differentiate between those perceptual activities carried out by peripheral nervous systems and those carried out centrally in the brain. At one time it was thought that the nerves merely transferred a 'map' of sense data to the brain where all the processing took place, however more and more is being learned about processing at the periphery. Such processing provides built-in and automatic discrimination and may underlie much of our visual appreciation of the real world. Discovery of these processes may make it possible to model the way in which we perceive objects, so accounting for a good deal of our aesthetics of the abstract. Much of the book is taken up with describing the experimental work on the nervous systems so essential for perception. For instance, individual neurons in the optic nerve of the frog each transfer only one of the following kinds of information: (1) edge detection (activity of nerve continues after transient darkening), (2) convex-edge detector (small dark objects), (3) detection of any change in contrast, (4) detection of darkening and (5) detection of the continuous level of darkness. Somehow these primitive operations contribute to the detection of flies. They are automatic, a kind of 'perceptual reflex'. They are unfortunately very difficult to classify with certainty, for different aspects of a single nervous mechanism may be revealed by different experimental approaches. This problem is stated more fundamentally as follows: 'There is no psychophysics of shape or pattern as there is for pitch or hue, or loudness or brightness. That is, form as a stimulus cannot now be specified in a way which leads to psychologically relevant measures in form' (p. 382). Maybe it is unwise to hope for a single mathematical theory that will be descriptive of the way a biological communication system works. Attempts to do just this with the information theory of Shannon have led to disenchantment. The book contains, in addition to this theory, other important mathematical constructs, such as signal detection models based on normal and Poisson statistics and decision models based on probability. These are not presented so much as models of communication but as relationships exactly defined and to be used in the kind of research that starts with a proposal of axioms from which a mathematical relationship may be constructed and then is followed by an attempt to demonstrate the existence of the relationship in the real world. As most of the research is in a 'natural history' phase, that is, the collection of data and attempts to describe and classify each individual stage in the communication process, the mathematics dealing with detection, learning and decision mechanisms are more important than all embracing hypotheses. The empirical approach will be of importance to aesthetics, for only this can uncover the mechanics of human behaviour. It is important to know how much of our appreciation of the visual...