Tested male albino rats with septal (N = 26) and dorsal hipppocampal lesions (N = 26) and sham-operated controls (N = 35) in 2 spontaneous alternation situations. In an ordinary T maze most septal and all hippocampal Ss perseverated, while most controls alternated. In a modified T maze intended to clarify the nature of the perseveration, all septal Ss perseverated stimuli, all hippocampal Ss perseverated responses, while most controls alternated stimuli. Septal lesions produced hyperreactivity to certain stimuli, while hippocampal lesions interfered with response control. This is contrary to prevalent views on the behavioral role of these structures. (19 ref.) (PsycINFO Database Record (c) 2006 APA, all rights reserved)