EFFECTS OF IRRADIATION ON BEHAVIOR AND BLOOD 



697 



ACTIVITY 



+ 4000 



f; +2000- 



-2000- 



Radiation 

 Day 



3 4 5 



WEEKS POST-RADIATION 



Fig. 4. Spontaneous cage activity. The ordinate is in difference of counts per week 

 from preirradiation le\el for the group. 



and week, but the differences were not statistically significant. By the sub- 

 jective method, the activity of the 400 r group was significantly lowered on 

 the 1st postirradiation day. 



With the electric eye method of recording cage activity used in the second 

 series of experiments (Fig. 4), we were unable to confirm the early post- 

 irradiation change suggested by the first series. There was no immediate 

 decrease in the cage activity of the experimental animals significantly greater 

 than that shown by the controls. However, during the 3rd and 4th post- 

 irradiation weeks, the experimental animals as a group were less active than 

 the control group (5% level of confidence). The activity for the total post- 

 irradiation period did not differ significantly from that of the control 

 animals. 



It is pertinent that the electric eye method, after a number of small 

 changes designed to reduce noise and social interaction (and to give greater 

 automation by the use of print-out counters), has proved quite sensitive to 

 such moderate environmental parameters as light and sound level, and 

 ambient warmth and cold (Devito and Smith, 1959; Isaac and Devito, 1958) . 



Object Manipulation 



The data obtained from the pedometers yielded no significant difference 

 between the experimental groups in 5 of the 6 postirradiation weeks, largely 



