PSYCHOLOGICAL MEASUREMENTS. 637 



SUMMARY OF PSYCHOLOGICAL RESULTS. 



The previous discussions of neuro-muscular measurements have not 

 depended upon introspective accounts. We have in each instance 

 made the measurements as objective as possible, and have given the 

 essential data and the best available material as comparison standards 

 for averages. It seems unwise to attempt a summary table or diagram. 

 Many of the measurements do not lend themselves readily in this case 

 to a numerical statement of differences on account of the small amount 

 of normal material which was actually secured from Squad A, and it 

 is this group in which we are most deeply interested, since it was with 

 them that the prolonged low diet was tried. While we may compare 

 the results of Squad A on low diet with the normal values for Squad B 

 and for other groups of men, yet it hardly seems permissible to sub- 

 tract for differences and to claim that these state in terms of magnitude 

 the effects of the reduced diet. In a few cases in which changes asso- 

 ciated with the low diet have been definite and progressive as, for 

 example, in the eye movements, it was found possible to compare the 

 performance of the first of the experiments with that shown on the 

 later dates and to state such differences in terms of per cent change. 

 In general, we have had to be satisfied, under the circumstances, with 

 statements of the direction of the effect, when such has existed, and 

 secondarily with general statements as to the probable amount of the 

 change. 



The most significant results found for the neuro-muscular tests are 

 given in simplest form for comparison. Opposite each measurement, 

 named and numbered in order, there is a brief statement of the low 

 diet effect, or of the apparent lack of such an effect. 



(1) Accuracy in tracing. Less accurate work (10) Word reactions. Not significantly changed. 



and less rapid improvement. (11) Number reactions. Not changed. 



(2) Pitch discrimination. Slightly poorer near (12) Visual threshold. Efficiency not decreased. 



the threshold. (13) Electrical threshold. Less sensitive and 



(3) Number cancellation. Slower improvement. less improvement. 



(4) Addition. Slower improvement in accuracy. (14) Eye movements. Slower speed. 



(5) Memory span. No certain change. (15) Finger movements. Slower speed, no 



(6) Strength of grip. Definitely lowered. indication of quicker fatigue. 



(7) Pulse with exertion. Lowered level of (16) Maze performance. Not significantly 



pulse-rate, nothing pathological.^ changed. 



(8) Patellar reflex. Slightly depressed. (17) Clerical tasks. Slower improvement. 



(9) Eye reactions. Not significantly changed. 



From this review of the results with the neuro-muscular measure 

 ments it appears that there was some disturbance in motor coordina- 

 tion and in muscular performances generally. The reactions, thres- 

 holds, and discriminations show less definite change. The same is true 

 for the more complex processes involved in memory, maze perform- 

 ance, and clerical tasks. In some of these processes not distinctly 

 muscular there appeared to be slower improvement under the low- 



*See section on pulse-rate, p. 415, for results. 



