Letter of application and précis of contributions to physiology of / Augustus D. Waller.

  • Augustus Desiré Waller
Date:
1895
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Licence: Public Domain Mark

Credit: Letter of application and précis of contributions to physiology of / Augustus D. Waller. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    Papers XX. (on the sense of effort) and XXV. (on the functional attributes of the cerebral corte>) deal with matters of mainly psychological interest, from a physiological standpoint. The nature of the arguments, which of necessity deal with much sub-positive matter, renders it difficult to give a short abstract of their contents. Experimental points presenting themselves in connection with psychological considerations involved in these two papers, and susceptible of actual demonstration, are dealt with in papers XXI., XXII., XXIII., and XXIV. XX. The Sense of Effort: an Objective Study. Brain, 1891, pp. 179-249. The main argument in this paper has been summarised as follows in “ An Introduction to Human Physiology (2nd ed., p. 550). “ Muscular sense, sense of movement, sense of effort, are terms used to denote the sensation that accompanies all voluntary muscular contractions. The factors of this composite sensation are :—(1) peripheral, arising from variations of tension and of pressure in the moved organs, i.e. in tendons, ligaments, cartilages, possibly in the muscle itself, certainly in the skin of the part; (2) central, arising from material changes accompanying the elaboration and emission of motor impulses. “ Whether a central as well as a peripheral factor contributes to the sensation of movement or effort has been much debated, and is still denied by some authorities, who regard it as of exclusively peripheral origin. The view that the central state is implicated in the formation of the sensation is materially supported by the objective signs of fatigue. Admitting that material changes after action occur in the same parts as material changes with action, we may learn the incidence of the effect by studying the incidence of the after-effect. Xow the after-effect of muscular action, subjectively felt as fatigue, is demonstrable by objective signs at the centre as well as at the periphery; from which we infer that the motor effect, which is subjectively felt as the sensation of movement or of effort, is associated with material changes at the centre as well as at the periphery. This is to say, that the sensation called ‘ muscular sense,’ ‘ sense of movement,’ ‘ sense of effort,’ is associated with changes at the centre and at the periphery ; we have no right to say that it is caused by changes in either of these situations to the exclusion of the other.” The same paper contains a description of the “ Dynamograph,” employed in the observations described in Paper XX. for the study of voluntary and of electrically excited fatigue. “ The value of the dynamometer is much increased if it is converted into a dynamo- graph ; the manner of maintenance of a prolonged maximum effort for regular periods^ or the character of a series of maximum efforts for regular periods, may then be recorded on a slowly travelling surface, e.g. a cylinder on the hour axis of an ordinary
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