EFFECTS OF RADIATION ON PSYCHOLOGIC PROCESSES 



739 



• MALE 

 O FEMALE 



10 12 14 16 18 20 22 24 



DAYS 



Fig. 8. Per cent errors on successive days of testing on spatial delayed response 

 for the 20 male Ss and for the 21 female Ss. 



low dose group, radiation subgroups F, G, and H constituted the medium 

 dose group, and radiation subgroups C, D, and E constituted the high dose 

 group. 



The initial study conducted by McDowell et al. (1959) was concerned 

 with progression through a series of training stages designed to prepare the 

 subjects for object discrimination testing on the WGTA. The three relative 

 radiation dosage groups were also compared on their initial object quality 

 discrimination learning. The radiation exposure of the irradiated subjects 

 predated the present study by 11 months. In this study, the higher the 

 relative radiation dosage, the faster the response to food, the slower the 

 response to a wooden object block, and the faster the discrimination of a 

 food-rewarded object block after object blocks had acquired the stimulus 

 value of food. 



The same subjects then were tested by McDowell et al. (1961a) on dis- 

 crimination problems with reduced stimulus cues and on spatial delayed 

 response problems. Figure 9 shows the per cent errors on successive 4 day 

 periods of testing on reduced cue problems for these 40 males and 24 

 females. The females learned significantly faster on this problem than males. 

 Figure 10 shows the per cent errors on successive 4 day periods of testing 



