Abstract
To test for behavioral stimulation of Bovard's bipartite emotional system, 60 male weanling albino rats were kept for 28 days in closed environments combining presence or absence of severe, random shock, and deprived, 2-dimensional and 3-dimensional visual stimulation, with experience of change or stability. Tests of exploration showed Ss from 3-dimensional environments explored most while those from 2-dimensional environments explored least. Shocked Ss tended to explore more than non-shocked Ss if the presenting stimuli were complex. In a choice situation, Ss initially explored the most complex stimuli offered them, suggesting further clarification is necessary of the concept of “complexity levels” based on past experience developing in organisms.