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Brain stimulation and learning. Switch-off behavior
BOOK REVIEWS
493
nerve and muscle fibres, the neural mechanism of the "F" wave, and the strength-duration parameters for stimulation of motor axons. The muchdebated relationship between threshold and conduction velocity among motor axons is also analysed to good effect. The second and third parts of the book are concerned with the nature and time course of the recovery cycle in a single motor axon following activation. So important are the results of this study that it comes as a surprise to realise that the methods are
relatively simple and do not depend on any recent technical developments. Dr. Bergmans points out that the same motor unit may be selected for study at subsequent examinations. Therefore it would seem that, although the present study is concerned only with results in healthy subjects, the technique has great promise for elucidating the course of progressive disorders such as motoneurone disease and muscular dystrophy. A. J. McCOMAS
Brain Stimulation and Learnin9. Switch-off Behavior (Abhandlungen aus dem Gebiet der Hirnforschung und Verhaltensphysiologie, Vol. 3), by H. NAKAO, 151 pages, 55 illustrations, 8 tables, VEB Gustav Fischer, Jena, 1970, M 35.--.
descriptions of some of the experimental procedures employed. The significance of SOB, and of the changes in SOB response time (the time between the onset of brain stimulation and the cat's termination of it) produced by the various experimental treatments is discussed in the final chapter which is entitled, rather grandiosely, "The neuropsychological mechanism of behaviour". The expectations from such a title are indeed exciting, though one is naturally sceptical that all that it implies could be dealt with adequately in just three pages ! Suspicions are confirmed on reading the first sentence, which states that "This chapter will be directed to distinguishing the SOB motivated by stimulation of the brain stem from classical conditioning (Pavlov)". Even this is slightly misleading, for in essence, it seems, Nakao's thesis is that "SOB represents a way to study instrumental learning in its pure form". The results of these experiments are interesting enough, though the interpretation of them is sometimes open to question. Most of the experiments have been published previously in Japanese journals between 1958 and 1968, and as a consequence a r e somewhat dated. Some of the experiments, however, are presented for the first time, but disappointingly little account has been taken of much of the recent work on motivational aspects of brain stimulation that has been published outside Japan. Of the approximately 200 references cited, there are only 29 which have been published since 1965, and of those, only 15 of them in Western journals. Nonetheless, Professor Nakao has made a useful contribution to the field, and this monograph now makes much of his work available in English for the first time. It will no doubt be of interest to a variety of research workers in the field of brain and behavi-
One's immediate impression from this slim monograph is that Professor Nakao's main interest is in the neurological basis of emotion. The first chapter reports a series of experiments which were designed to re-examine Masserman's (1941, 1950) view that electrical stimulation of the hypothalamus did not produce true emotionality but instead merely evoked the motor manifestations of rage and fear. In the second chapter is presented a fairly detailed examination of the effects of electrical stimulation of quite a number of brain structures on what Nakao calls "emotional responses". That such a term is a rather nebulous one is further indicated by the inclusion of a study on "alimentary behaviour", in which it was found that various appetitive behaviours, leading finally to the consummatory response of eating, could be reliably evoked by electrical stimulation of the appropriate area of the hypothalamus. The remaining eight chapters are devoted to a series of experiments in which cats were trained to make an instrumental response in order to switch off aversive electrical stimulation of the hypothalamus and brain stem. Changes in cortical and hippocampal electrical activity were studied during the learning of this escape response, which Nakao calls "switch-off behaviour" (SOB), and the effects of brain stimulation, brain lesions, drugs and delayed reinforcement on SOB performance were also investigated. Nakao's careful observations are reported in considerable detail, but in a style of English which is sometimes quaint, even archaic. It is, however, unfortunate that the detail found in the experimental observations is not always to be found in the
Mechanisms o f Motor Skill Development (Developmental Sciences Series), by K. J. CONNOLLY(Ed.), xv + 393 pages, 91 illustrations, 23 tables, Academic Press, London, New York, 1970, £ 6.00.
our.
K. H. NOTT
This is the report of a study group organized by the Centre for Advanced Study in the Developmental Sciences in collaboration with the Ciba Foundation and held in November, 1968. After
Z neurol. Sci., 1972, 15:491-496
493
nerve and muscle fibres, the neural mechanism of the "F" wave, and the strength-duration parameters for stimulation of motor axons. The muchdebated relationship between threshold and conduction velocity among motor axons is also analysed to good effect. The second and third parts of the book are concerned with the nature and time course of the recovery cycle in a single motor axon following activation. So important are the results of this study that it comes as a surprise to realise that the methods are
relatively simple and do not depend on any recent technical developments. Dr. Bergmans points out that the same motor unit may be selected for study at subsequent examinations. Therefore it would seem that, although the present study is concerned only with results in healthy subjects, the technique has great promise for elucidating the course of progressive disorders such as motoneurone disease and muscular dystrophy. A. J. McCOMAS
Brain Stimulation and Learnin9. Switch-off Behavior (Abhandlungen aus dem Gebiet der Hirnforschung und Verhaltensphysiologie, Vol. 3), by H. NAKAO, 151 pages, 55 illustrations, 8 tables, VEB Gustav Fischer, Jena, 1970, M 35.--.
descriptions of some of the experimental procedures employed. The significance of SOB, and of the changes in SOB response time (the time between the onset of brain stimulation and the cat's termination of it) produced by the various experimental treatments is discussed in the final chapter which is entitled, rather grandiosely, "The neuropsychological mechanism of behaviour". The expectations from such a title are indeed exciting, though one is naturally sceptical that all that it implies could be dealt with adequately in just three pages ! Suspicions are confirmed on reading the first sentence, which states that "This chapter will be directed to distinguishing the SOB motivated by stimulation of the brain stem from classical conditioning (Pavlov)". Even this is slightly misleading, for in essence, it seems, Nakao's thesis is that "SOB represents a way to study instrumental learning in its pure form". The results of these experiments are interesting enough, though the interpretation of them is sometimes open to question. Most of the experiments have been published previously in Japanese journals between 1958 and 1968, and as a consequence a r e somewhat dated. Some of the experiments, however, are presented for the first time, but disappointingly little account has been taken of much of the recent work on motivational aspects of brain stimulation that has been published outside Japan. Of the approximately 200 references cited, there are only 29 which have been published since 1965, and of those, only 15 of them in Western journals. Nonetheless, Professor Nakao has made a useful contribution to the field, and this monograph now makes much of his work available in English for the first time. It will no doubt be of interest to a variety of research workers in the field of brain and behavi-
One's immediate impression from this slim monograph is that Professor Nakao's main interest is in the neurological basis of emotion. The first chapter reports a series of experiments which were designed to re-examine Masserman's (1941, 1950) view that electrical stimulation of the hypothalamus did not produce true emotionality but instead merely evoked the motor manifestations of rage and fear. In the second chapter is presented a fairly detailed examination of the effects of electrical stimulation of quite a number of brain structures on what Nakao calls "emotional responses". That such a term is a rather nebulous one is further indicated by the inclusion of a study on "alimentary behaviour", in which it was found that various appetitive behaviours, leading finally to the consummatory response of eating, could be reliably evoked by electrical stimulation of the appropriate area of the hypothalamus. The remaining eight chapters are devoted to a series of experiments in which cats were trained to make an instrumental response in order to switch off aversive electrical stimulation of the hypothalamus and brain stem. Changes in cortical and hippocampal electrical activity were studied during the learning of this escape response, which Nakao calls "switch-off behaviour" (SOB), and the effects of brain stimulation, brain lesions, drugs and delayed reinforcement on SOB performance were also investigated. Nakao's careful observations are reported in considerable detail, but in a style of English which is sometimes quaint, even archaic. It is, however, unfortunate that the detail found in the experimental observations is not always to be found in the
Mechanisms o f Motor Skill Development (Developmental Sciences Series), by K. J. CONNOLLY(Ed.), xv + 393 pages, 91 illustrations, 23 tables, Academic Press, London, New York, 1970, £ 6.00.
our.
K. H. NOTT
This is the report of a study group organized by the Centre for Advanced Study in the Developmental Sciences in collaboration with the Ciba Foundation and held in November, 1968. After
Z neurol. Sci., 1972, 15:491-496