Administered a large battery of behavioral tests to 11 normal mice and to 20 mice with varying degrees of otoconial agenesis due to genes affecting vestibular development. Many significant differences were found, but a factor analysis revealed that the variance on the 11 best tests could be accounted for in terms of 2 underlying variables. Factor I, the more important of the 2, was associated with activity, habituation, and spontaneous alternation. Factor II appeared to represent a fear of new stimuli or situations. In both cases, factor scores were highly related to the degree of otoconial deficiency. In a 2nd experiment, a subgroup of 5 Ss with severe otoconial agenesis displayed hyperactivity and a total absence of either habituation or spontaneous alternation. In these Ss brain and body development were stunted, and the reactions to amphetamine and physostigmine were opposite to those seen in normal Ss. Results support the idea that the static organs contribute importantly to spatial orientation and suggest that early-onset vestibular defects can result in profound alterations of emotionality. (27 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1979 American Psychological Association.
