Material relating to Sir Charles Sherrington's interest in fatigue- No links match your filters. Clear Filters
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Related toC.S. Sherrington, The Integrative Action of the Nervous System (New Haven: Yale University Press, 1906).
Description:from 1961 paperback of 2nd ed. (1947).
On declining nervous response as an aspect of fatigue:
'A spinal reflex under continuous excitation or frequent repetition becames weaker, and may cease altogether. This decline is progressive, and takes place earlier in some kinds of reflexes than it does in others. …
A reflex as it tires shows other changes besides decline in amplitude of contraction...; it becomes tremulous, and the tremor becomes progressively more marked and more irregular... Finally, an irregular phasic tremor of all the muscles is all that remains. It is not the flexor muscles themselves which tire out, for these, when they contract no longer during the flexion-reflex, still contract in response to the scratch-reflex which also employs them.' (215)'… the phenomena are not referable to [(215), (217)] the muscle, for when excited through other reflex channels, ot through its motor nerve directly, the muscle shows its contraction well.' (215-217)
On the role of fatigue in the expression of relfex arc competing for the same 'final common path' (ie. set of motor neurons):
'In the hind limb of the spinal dog the extensor-thrust is in-elicitable during the flexion-reflex... But when the flexion-reflex is kept up by appropriate stimulation of a single point over a prolonged time , so that it shows fatigue, the 'extensor thrust' becomes again elicitable... In other words, it can dispossess the rival reflex from a common path when that rival is fatigued, though it cannot do so when the rival action is fresh and powerful.' (223)
The function of fatigue:
'It seems a process elaborated and preserved in the selective evolution of the neural machinery. One obvious use attaching to it is the prevention of the too prolonged continuous use of a 'common path' by any one receptor. It precludes one receptor from occupying for long periods an effector organ to the exclusion of all other receptors. It prevents long continuous possession of a common path by any one reflex of considerable intensity. It favours the receptors taking turn about. It helps to insure serial variety of reaction. The organism, to be successful in a million-sided environment, must in its reactions be many-sided. Were it not for [(224) (225)] such so-called 'fatigue', an organism might, in regard to its receptivity, develop an eye, or an ear, or a mouth, or a hand or leg, but it would hardly develop the marvellous congeries of all those various sense-organs which it is actually found to possess.' (224-225)
On the relevance of fatigue to the psychology of the senses:
'If instead of motor effects sensual are examined, analogous phenomena are observed. A visual image is more readily inhibited by a competing image in the same visual field when it has acted for some time than when it is first perceived (W. McDougall).' (224) [n. to McDougall, W. (1901) Mind, x, no. 37.]
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Related toBritish Association, British Medical Journal, 19 September 1908 (2), pp. 836-839.
Description:Includes a report of a discussion on the instruction of schoolteachers in physiology and hygiene, chaired by Sherrington, at a meeting of the British Association: ‘Professor Sherrington, who opened the discussion, contended that during the last generation there had been a greater advance in physiology and hygiene than in any other department of knowledge. At a time like the present, when socialistic ideas were coming to the front, the care of the children was passing more and more out of the hands of the parents into those of the school teachers. The tendency was one which he did not regret, for the teachers were alive to their responsibilities and were most enthusiastic in attaining knowledge to enable them to do the best for the health of their children. The human body might belooked upon as a complex machine, and those who were in charge of machines were generally expected to have some idea how they worked. Many aspects of fatigue manifested themselves in the schoolroom, and the teacher should be capable of recognizing fatigue.’ (838-839) - supported by Thompson, Gotch and others (839).
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Related toSpecial Correspondence, British Medical Journal, 25 October 1902 (2), p. 1371.
Description:- notes that CSS gave ‘a most interesting lecture in the Physiological Theatre in Owens College, on October 17th, to members of the Froebel society, Teachers Guild, and the Society for Child Study. The subject selected was “Fatigue.” After explaining the phenomena of muscular fatigue as shown by a nerve-muscle preparation, and anaylsing the phenomena exhibited by it, he dwelt on the breakdown that takes place at the seat of the junction of nerve and muscle. The phenomena of Curare poisoning led one to to the theory that the action was largely a chemical one. The phenomena of so-called fatigue of the flexor muscles of the middle finger were shown by means of the ergograph of Mosso. On the sensory side, the effects of walking, play and muscular action on such phenomena as the sensibility to touch were illustrated. The effects of a bright white light in diminishing the brightness apart from the hue of a colour was brought home to the audience by means of a simple but striking experiment. Altogether the lecture seemed to be highly appreciated by the large audience.’ (1371)
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Related toThe British Association, Opening Address by Prof. C. S. Sherrington, Nature, 8 Sept 1904 (70), pp. 460-466.
Description:In the speech Sherrington notes the importance of fatigue as a factor affecting competition between rival reflexes for control over the final common path (ie. set of motor neurones relating to a specific action):
'Whatever be the nature of the physiological processes in the conflict between the competing reflexes, the issue of that conflict - namely, the determination of which competing arc shall for the time being reign over the final common path - is largely determined by three factors. One of these is the relative intensity of the stimulation of rival the reflexes. An arc strongly stimulated is ceritus paribus more likely to capture the common path than one which is excited feebly...
A second main determinant for th issue of the conflict between the rival reflexes is the functional species of those reflexes. Arcs belonging to species of receptors which, considered as sense-organs, provoke strongly affective sensation - e.g. pain, sexual feeling, &c. - with the final common path with remarkable facility...
A third main factor... is "fatigue." An arc under long continuous stimulation of its receptor tends, even when it holds the common path, to retain its hold less well. Other arcs can then more readily dispossess it. A stimulus to a fresh arc has, in virtue of its mere freshness, a better chance of capturing the common path... This waning of a reflex under long-maintained excitation is one of the many phenomena that pass in physiology under the name "fatigue." Its place of incidence lies at the synapse. It seems a process elaborated and preserved in the selective evolution of the neural machinery. It prevents long continuous possession of a common path by any ne reflex of considerable intensity. It favours receptors taking turn about. It helps to ensure serial variety of reaction. The organism, to be successful in a million-sided environment, must in its reactions be many-sided. Were it not for such so-called "fatigue," an organism might, in regard to its receptivity, develop an eye, or an ear, or a mouth, or a hand or leg, but it would hardly develop the marvellous congeries of all those sense-organs which it actually does.' (466)
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