LOCATION OF THE SENSATION OF MOVEMENT. 



Z. PAULINE BUCK. 



Due to the fact that there was some controversy as to the origin of the 

 sensation of movement and in answer to the question whether one is consciout- 

 of the i)osition of a member on tlie basis of muscle sense only, the following 

 experiment was undertaken in the latter half of the school year 1915-1916. 

 The problem was carried out according to the suggestion of Doctor J. F. 

 Shepard. The experimental work was done in the Psychological Laboratory 

 of the University of Michigan. The aim was to see if the tongue, a member 

 controlled entirely by muscle, could be trained to move in a definite direction 

 at will, all supplementary sensations such as contact and vision being ruled 

 out. 



For this purpose apparatus was constructed which would hold the sub- 

 ject's head in a stationary position and at the same time, by clamping over the 

 lower and upper teeth hold the mouth wide open. A tongue pen was so con- 

 structed as to automatically vary in length as the writing surface was nearer 

 or farther from the subject due to the tongue describing an arc rather than a 

 straight line. Two clamp standards held a rectangle of colluloid upon which 

 was drawn a vertical line. This was placed before the subject so that by pro- 

 jecting the tongue he could comfortably reach both bottom and top of the line. 

 Behind the rectangle was a mirror so that the subject could see the position 

 of the tongue in practice work. 



The subject was allowed to draw the tongue from the bottom to the top 

 of this line three times, then the mirror and celluloid were moved away and a 

 kymograph with smoked paper drawn up. Upon this the subject tried to 

 reproduce the line practiced on the rectangle. Six trials were given each day, 

 each preceded by three practice drawings. The experiment was carried out at 

 regular intervals. When the subject reached a fair degree of perfection he 

 was given a horizontal line to draw. Five subjects were used. At the close 

 of each day's series the subject was asked to write an introspection and to 

 draw a series of six vertical lines as a basis of comparison of the steadiness 

 of the subject. 



A comparison of the records made by each subject at the beginning of the 

 experiment and those made at the close, shows a very evident improvement in 

 the character of the lines. The introspections were also of interest although 

 not uniform in substantiating the muscle sense of definite position. The intro- 

 spection in this respect differ in the same subject from day to day. They over- 

 balance very definitely, however, in the direction of consciousness of tongue 



21st Micb. Acad. Sci. Kept., 19X9. 



