Some Effects of a Lethal Dose of X-Radiation Upon Retention in Monkeys

The effects of repeated doses of total-body X radiation on motivation and learning in rhesus monkeys.

“…The irradiated monkeys did, however, show significant decreases in general body activity and in appetite, with these decreases tending to become greater as the absorbed cumulative dose of rocntgen units increased. The results of the learning tests parallel those of Kaplan, Gentry, Melching, and Delit (7), who found that accuracy of performance and reaction times in a discrimination-retention problem were not significantly affected by a dose of X radiation which shortly proved to be lethal. They also found a rapid increase after radiation in failures to respond, which may be related to the activity and appetite decreases obtained in the present project.…”

“…Several studies (3,4,7) have reported the effects of X radiation on the physiology and behavior of animals, but in general these studies have employed a single, large dose of radiation. The present study was undertaken to determine the progressive behavioral and physiological changes following repeated mild doses of X radiation over a long period of time.…”

Learned performance of monkeys after single and repeated X irradiations.

“…Performance of the irradiates on avoidance learning and delayed response was as efficient as that of the normals. These findings corroborate and augment the findings of other laboratories on these tasks (1,2,3,4,5,9).…”

Protracted low-dose ionizing radiation effects upon primate performance

“…For example, Riopelle (16) found no evidence of a behavioral change using a task requiring a delayed response in monkeys exposed to 400-rad whole-body X-rays. Within the same dose range, Kaplan et al (9) found no decrement in the retention of highly discriminative tasks. Leary and Ruch (10), and McDowell and Brown (i2), respectively, observed a decline in cage activities in the 400 and 544-700 rad whole-body range of X-rays.…”