642 HARRY F. HARLOW 



The data from the total group demonstrate that conditioned fluid aversion 

 can be produced in the monkey, even if there are considerable individual 

 differences. Our results and our difficulties are similar to those reported by 

 Kimeldorf et al. (1960) for the cat. However, it is clear that after technical 

 difficulties are overcome the Garcia-Kimeldorf phenomenon can be demon- 

 strated to hold for various species. 



Although the Garcia-Kimeldorf phenomenon is an established fact, the 

 most recent studies by these investigators suggest that the primary mecha- 

 nisms involved do not relate to radiation-induced CNS changes. If this is 

 true, the total body of radiation researches in neurology and psychology 

 present data closely correlated and integrated. 



In the future we may expect a shift of interest in assessing behavioral 

 effects, particularly those relating to learning, from whole body radiation 

 studies of the mature subject to the effects of radiation on the animal in 

 utero and on the neonatal and infantile animal. Direct radiation of specific 

 cerebral centers and areas, including the cortex, remains a worthwhile field 

 of investigation. The effects of long term, chronic radiation from various 

 sources on various species is relatively unexplored. Regardless of subject or 

 dose, additional attention will doubtlessly be given to "nonlearning" tests 

 covering a wide variety of behaviors. 



Radiation research in the past has given primary emphasis to the effect 

 of varying doses on groups of subjects. In the future more attention prob- 

 ably will be given to the study and prediction of individual differences. 

 Such problems become more and more important as one progresses from 

 drosophila to mouse, rat, monkey, and man. 



References 



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Zellmer, R. W. 1960. Acute effects of gamma radiation in primates. Radiation 



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