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Six normal, 10 low-dose irradiated (77-154 rep), 9 intermediate-dose irradiated (308 rep), and 4 high-dose irradiated rhesus monkeys (616 rep) were tested to a criterion of 21 correct responses (24 trials a day) for two successive days on each of eight visual acuity problems presented in order of increasing difficulty. Each problem required the subject to choose between circles and circles with breaks in order to procure a food reward. Previous visual acuity testing had shown a deficit only in the high-dose irradiated group during the first year following the radiation exposure to which the experimental animals had been subjected three years prior to the initiation of the present study. The results of the present study demonstrated that: (1) The visual acuity deficit noted during the first year after exposure in the high-dose irradiated monkeys (616 rep) was still manifested three years after exposure. (2) Monkeys in the intermediate-dose group (308 rep), that had shown no visual acuity deficit during the first year after exposure, manifested such a deficit three years after exposure. (3) An interpretation of the results in terms of a basic deficit in learning ability for the monkeys of these two groups is contraindicated by their superiority over normal and low-dose irradiated monkeys on the initial and easiest problem. (Author)

A study was made of the effects of distraction upon freecage behavior to determine the relation between amount of previous whole-body radiation exposure of adult male rhesus monkeys and behavioral stability under conditions of social distraction. The irradiated monkeys had been exposed to atomic weapons detonations 31/2 years earlier at various doses of radiation, from 10-rep neutron plus 70-r neutron radiation to 54-rep + 554-r doses. Other monkeys were chronically exposed 6 years earlier in the lab to doses up to 670 rem. Exposed monkeys were each systematically observed once, over a 3-day period, under each of three conditions of social distraction. One condition had no social stimuli present, a second had an adult female monkey at menses present, and the third had an adult female monkey at estimated time of ovulation present. Order of condition presentation was counterbalanced over days within each radiation-dosage group. The female monkey was, in each instance, visually, but not physically accessible, being placed in a cage three feet from the cage housing the experimental male monkey. The study was repeated one month later with the same experimental subjects. Statistical treatment of each set of data yielded a significant radiation groups-by-conditions interaction. Each interaction reflectedmore » a positive relation between amount of previous whole-body radiation exposure and behavioral stability under conditions of social distraction. These results are interpreted as reflecting decreased social distractibility accruing to whole-body radiation exposure and are in accord with findings of previous studies concerned with the effects of nonsocial distractions upon performance of specific laboratory tasks. Whether these results reflect direct effects of radiation exposure upon the endocrine system of the monkey remains to be determined. (BBB)« less

This study was designed to determine whether focal-head irradiated rhesus monkeys differ from normal monkeys in a manner analogous to that previously found in whole-body irradiated monkeys with respect to response latencies under both familiar and novel stimulus conditions. Five control and four focal-head irradiated rhesus monkeys with nearly identical training histories were used; the latter were survivors of a focal-head irradiation study conducted four years earlier. They had received 3000 r x radiation to the inferior parietal lobule and posterior aspect of the temporal lobe of the brain, and 30 days later the same dosage to the same area of the brain. The testing was conducted in a modified version of the Wisconsin General Test Apparatus, with 24 trials per day for two days, on response latency to a single food-rewarded wooden block placed randomly over either of the two extreme food-well positions. Then, 24 trials were conducted per day for two days on response latency to either the same food-rewarded wooden block or to a novel nonrewarded wooden block presented simultaneously. On the single-block condition, median response latencies of the two groups were comparable and the groups improved in a similar manner with practice. Optimal performance latencies weremore » also comparable for the two groups. When the novel nonrewarded stimulus block was introduced, both groups manifested comparable disruption of median response latencies, but disruption of optimal response latencies was shown only by the focalhead irradiated group. The findings show that monkeys with previous focal-head irradiation of the posterior association areas, unlike relatively high-dose whole-body irradiated monkeys, manifest median response latencies comparable to those of controls. These data indicate the lasting effects of focal-head irradiation with x rays, and suggest that the sites of permanent damage for monkeys given sublethal whole-body radiation exposure differ from the sites irradiated in the present subjects. (BBB)« less

This study was conducted to compare the effects of various extra-cage social stimuli on the free-cage behavior of normal monkeys and of monkeys with previous focal-head irradiation. Four control and four focal-head irradiated monkeys with nearly identical training histories were used, the latter being the survivors of a focal-head irradiation study conducted 41/2 yr earlier. They had received 3000 r x radiation to an area of the head containing the inferior parietal lobule and posterior aspect of the temporal lobe, and repeated 30 days later Each group was systematically observed under each of four socialstimulus conditions with the order of condition presentation counterbalanced within each group over a 4-day period. The four social-stimulus conditions included: absence of social stimulus, an adult male monkey, an adult female monkey at menses, and an adult female monkey at estimated time of ovulation. The socialstimulus conditions showed no effect on the nondirected activities of the normal monkeys, but produced a marked decrease in the nondirected activities of the focal-head irradiated monkeys, with the least number of such activities being manifest in the presence of the adult female monkey at ovulation. Under conditions of social stimulation the normal monkeys showed a marked decrease in totalmore » directed activities of the non-social-stimulus condition, while the focal-head irradiated monkeys showed a marked increase, the effect in each instance being greatest in the presence of the female at ovulation. The directed activities, toward the cage as an object, of the controls decreasrd and those of the experimental subjects increased. The controls were more than twice as responsive to the female at estimated time of ovulation as to the other two social stimuli, while the experimental monkeys were equally responsive to each of the three social stimuli. The data suggest the presence of psychic blindness in the monkeys previously exposed to focal-head irradiation of the temporal lobes. (BBB)« less

(1959). The Effect of the Introduction of Novel Stimuli upon Manipulation in Rhesus Monkeys. The Journal of Genetic Psychology: Vol. 94, No. 1, pp. 107-111.

Effect of thermal injury on tissue metabolism was studied by comparing the glucose metabolism of normal rat diaphragm tissue incubated in plasma from injured (plasma taken 15 min. after injury) and uninjured rats. Glucose concentrations in the plasma from the burned and control rats were made comparable to compensate for the hyperglycemia due to injury. An inhibition of glucose uptake by the diaphragm tissue incubated in plasma from burned rats was demonstrated, whereas the QO2 and the conversion of glucose-U-C14 to C14O2 were not significantly changed. This inhibition of glucose uptake was observed when dialyzed plasma from burned animals or the dialysate was used. Epinephrine under certain circumstances inhibited glucose uptake. These studies indicate that immediately after thermal injury, a disturbance in glucose utilization occurs; this disturbance appears to be other than in the conversion of glucose to CO2; a dialyzable principle is present in the plasma; and epinephrine is not excluded as a causative agent.