744 



W. LYNN BROWN AND ARNOLD A. McDOWELL 



Fig. 15. Mean median latencies for low dose (Group 1), intermediate dose (Group 

 2), and high dose (Group 3) irradiated 5s on response to (1) a single food-rewarded 

 object block in a constant position, (2) the same object block with left-right position 

 "randomized," and (3) either the same food-rewarded object block or a novel non- 

 food-rewarded object block presented simultaneously. 



latency to a single food-rewarded object block in a constant position, on 

 response latency to the same object block with left-right position "random- 

 ized," and on response latency to either the same food-rewarded object block 

 or a novel nonfood-rewarded object block presented simultaneously. Figure 

 15 shows the mean median latencies for each radiation group under each con- 

 dition of testing. Statistical analysis of the data yielded a significant condition 

 effect and a significant groups X conditions interaction. With the single 

 block conditions, the higher the relative radiation dosage, the higher the 

 response latency. When the novel unrewarded stimulus block was introduced, 

 the higher the relative radiation dosage, the less the disruption of response 

 latencies. The high dose subjects continued to respond just as they had in 

 the single object "randomized" position condition. 



While it is recognized that the null hypothesis is never accepted, the 

 consistent negative findings on concept formation problems with both of 



