EFFECTS OF RADIATION ON PSYCHOLOGIC PROCESSES 



737 



parable ages differ in distractibility or in concentration of attention on the 

 prepotent stimulus in both a test situation involving the presence of food 

 and a free cage environment with no food. The study proposed further to 

 test the prediction of facilitated delayed response performance by that sex 

 showing the greater concentration of attention if, in fact, evidence for sex 

 differences in attention were manifest. 



One experiment concerned a comparison of 21 female and 20 male mon- 

 keys on preliminaiy WGTA training involving food as the prepotent stim- 

 ulus. Figure 6 shows the per cent of each sex having completed preliminary 

 WGTA training on successive days of testing. Females required significantly 

 fewer days to complete this training than males. A second experiment com- 

 pared the sexes on object-directed responses in the free cage environment. 

 Figure 7 shows the proportion of total object responses directed by each 

 sex to each of the four stimulus classes. Each of the sexes ordered its re- 

 sponses significantly and in the same manner with respect to these stimulus 

 classes. Females directed a significantly larger proportion of their object 

 responses to the prepotent stimulus class than males. Because of these find- 

 ings, facilitated spatial delayed response performance was predicted for 

 females. Figure 8 shows the per cent errors on successive days of spatial 



Fig. 6. Per cent of 5s of each sex having completed preliminary WGT.\ training 

 on successive days of testing. 



