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pure peripheral input, dependent though the cortex is on information from the feature detectors," the interpreting brain also seems to be carrying out a function assigned to consciousness in the list. These criticisms are made in order to illustrate that in the treatment of conscious perceptions there are several inadequacies . Two subsequent chapters deal with motor control, which is a field to which Granit has contributed much. They are authoritative neurobiology, but considerations of purpose are only lightly touched on at the very end: "Some idea of will power can be obtained by pitting a demanded set of instructions against automatic segmental mechanisms and determining to what extent die latter can be overridden. Both for theoretical and for clinical purposes such studies of the act of willing or demanding are of considerable importance. Nevertheless will and demand remain what they always were—psychological concepts required in the study of behaviour." There are good general ideas in the last chapter under such headings as integration, models and hypotheses, cybernetic explanations, engram formation, and the psychophysical approach. However, they are not treated in depth. No new theme is developed. It is good to see the historical section on cybernetics: "Inasmuch as cybernetics is the science of regulation and control, it has had a long clandestine existence in physiology, because the latter science has always been concerned with regulated and controlled processes." This was never recognized by Wiener. Later he warns against "prematurely assigning too great a role to the best analysed single neurons of the cortex." Granit has written a book that should be required reading for all investigators of the central nervous system. The besetting sin in this technological age is a narrowness of vision that impedes the development of conceptual syntheses, which is the principal goal of science. John C. Eccles Contra (Locarno) TI CH 661 1 Switzerland Local Circuit Neurons. By Pasko Rakic. Cambridge, Mass.: M.LT. Press, 1977. Pp. 161. $8.95. This book is a republication of a Neurosciences Research Program Bulletin, volume 13, number 2. It begins with an account of the reason for the invention of the term local circuit neurone (LCN) to replace the classical term "interneurones ." But it is important to realize that in most of the accounts only inhibitory interneurones are considered as local circuit neurones, and in particular there is emphasis on the inhibitory interneurones that lack axons or that appear to be effective without impulse generation. I am of course very pleased that the old concept of the uniqueness of the inhibitory interneurone is substantiated in so many interesting neuronal systems, but it does not seem to be recognized that 20 years ago this was a revolutionary and much criticized hypothesis. It is unfortunate that there seems to be no overt reference to the exclusive inhibitory character of local circuit neurones as considered here. But the omission of the Perspectives in Biology and Medicine · Spring 1978 | 469 granule cells of the cerebellar cortex and of the bipolar cells in the retina seems to make it clear that excitatory interneurones are not admitted to the LCN club! A remarkable series of discoveries found that inhibitory interneurones may work without impulse generation, acting by reciprocal synapses as first described in the olfactory bulb and the retina. The LCNs of this type are described at additional sites—the lateral geniculate body, the medial geniculate, and the thalamus. However, other LCNs are of the conventional inhibitory interneuronal type such as in neocortex and the cerebellar cortex. Nothing new is added in these sections. Another new term is "local neuronal circuit" that designates "the independent reverberation of impulses confined only to part of a cell membrane, to a single dendrite, or to one or several LCN's." Frankly, I do not understand what is meant by this strange definition. Certainly Shepherd has given a very good comparative study of various circuits in which LCNs are concerned. But one wonders about the statement: "In each case, the function of the local circuit is to integrate information at the local level rather than to propagate it out of a given structure." It sounds as if local integration is sufficient unto itself. Fortunately, the nervous system is not...


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