Observations of canal sickness and adaptation in chimpanzees and squirrel monkeys in a slow rotation room. (Rep. No. 59).

Abstract

5 chimpanzees and 11 squirrel monkeys were exposed to rotations varying from 1.9 to 10.0 rpm in the Pensacola slow rotation room. Two of the chimpanzees and ten of the squirrel monkeys manifested signs of canal sickness similar to that experienced by normal humans. Those animals that failed to manifest canal sickness exhibited evidence of impaired vestibular function as demonstrated by cold water caloric testing. The symptomatology of canal sickness was similar in the susceptible animals and could be graded as to severity. Adaptation to the unusual stimulus during constant rotation could be demonstrated with both the chimpanzee and the squirrel monkey. This adaptation appears to be of short duration. These findings are highly encouraging for the use of monkeys and higher apes in studies of the manifestations and etiology of motion sickness of all types.