AN EXPERIMENTAL STUDY ON AFTER-MEAL RECESS TIME IN CASE OF MENTAL WORK : As seen from uropepsin, urinary Na/K, quantity of salivary secretion Kraepelin's addition valiable curve, and colour naming

In order to determine the effect of duration of after-meal recess on the living body in the case of mental work, observations we made on such indications of fatigue as Kraepelin's addition variable curve, uropepsine excretion, sodium and kalium excretion in the urine, Na/K equivalent ratio, quantity of salivary excretion, and colour naming. A. Effect of duration of recess after meal. One hour of rest was admitted before midday meal, and Kraepelin's additional work was assigned after different durations of recess following that meal. (no after-meal recess, and 30, 45 and 60 minutes of intermission including lunch time) 1. When assignment of work was nof followed by after-meal recess, there appeared a tendency to develop increased uropepsin excretion by meal. 2. The shorter the after-meal recess, the more uropepsine excreted at rest time following conclusion of work. Groups of persons admitted no after-meal recess or 30 minutes of intermission including meal time showed more significant development in the excretion than the group given 60 minutes of such recess. 3. Indication of fatigue by way of Kraepelin's addition variable curve was apparent in groups admitted no after-meal recess or 30 minutes of intermission, but was not encountered in the group given 45 minutes of recess. B. Effect of duration of intermission at lunch time upon 8 hours detained work. Kraepelin's whole day work was assigned, and then observation was conducted upon effect of recess at lunch time on fatigue due to the work performed in the morning. Rest time at lunch was 30 or 60 minutes, and recess totaling 30 minutes was alloted in the morning and afternoon. For the purpose of control experience recess at lunch and during work were established to be 60 minutes respectively. 1. Subjects, who was assessed as fatigue type by Kraepelin's addition variable curve, showed the most remarkable indication of fatigue by the curve in the experiment of 30 minute recess at lunch, and also a marked tendency for gradual decrease in Kraepelin's addition per minute. 2. Variation in colour naming velocity did not indicate any trend for the difference of intermissions. 3. As to reduction in salivary secretion at intermission at lunch and after conclusion of work, less reduction was found in the case of 30 minute recess at lunch. 4. Na and K excretion in the urnie was retained at high level in the afternoon work when 30 minute recess at lunch was kept. Na/K equivalent ratio did not decrease as well when 30