Page:American Journal of Psychology Volume 21.djvu/551

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VOLUNTARY MOVEMENT
539

was radically changed, making a condition in essentials the reverse of the upside-down writing. It is therefore clear that in writing movements the muscular element can be changed (not eliminated) with less interference with the activity than is produced when the visual element is changed.

This suggests that on the sensory side writing may be regarded as a visual-kinaesthetic activity with vision representing the extra-bodily aspect of the total process and the muscular sense the intra-bodily aspect. As a matter of fact it would seem that every new voluntary activity whose object is an extra-bodily end requires the sensory or perceptual representation of those two aspects of the process and these two only, the one representing the status quo of the thing being manipulated, the other that of the bodily member immediately concerned with the manipulation. Our writing experiments show that in the more highly volitional tests attention is uniformly upon the extra-bodily aspect unless conditions are such that reaction to the visual elements can take place only by way of complex interpretation. The study of the cases of anaesthesia (to be described later) will show that the muscular sense normally serves the function of giving the status quo of the bodily member, but that in case of tactual-kinæsthetic paralysis vision is called upon to perform this function. These facts agree with the facts obtained in the present study. Moreover the facts there obtained agree also with those obtained in the writing experiments in this, that in the automatization of voluntary movement the extra-bodily elements drop out of consciousness before those representing the position of the member in movement. This is abundantly illustrated by the fact that every experiment with the upside down and mirror writing shows attention to the result, and not only that, but visual attention wherever it is practically possible. On the other hand in those experiments in which the movements and the manner of control were familiar but the copy unfamiliar and meaningless, as in case of the nonsense syllables, there was a minimum of attention to the result. The same thing is true of copying nonsense syllables and repeating the Greek and German alphabet. In this case attention fluctuated from the copy to the alphabet but not to the result put on paper. In both these cases the handwriting suffered somewhat, as is shown by comparison with the other experiments in which there was visual attention to the result. It suffered not only in the large co-ordinations such as following the line, spacing, etc., which involve a spatial reference for which the muscular sense is inadequate, but also, in instances in a marked degree, in the details of the movements which apparently have "gotten into our muscles" and which