In writing a review of the literature on any aspect of the hippocampus it seems obligatory to state that, despite intensive research, the functional significance of this structure remains enigmatic. Such a statement remains largely true at this time, a testimony to the fact that its function is not easily reducible in simple terms to either sensory or motor processing per se. The electroencephalographic (EEG) patterns indigenous to the hippocampal formation have long been considered to be a reflection of the neural processing going on in these structures. Therefore it seems reasonable to assume that study of the EEG patterns will serve to elucidate at least some aspects of hippocampal function. The majority of studies have concentrated on one particular EEG waveform, the rhythmical slow wave activity termed hippocampal theta. Klemm (1976a) pointed out in his review that most experiments have involved correlating various physiological and behavioral phenomena with spontaneously occurring theta activity. Unfortunately, as he also pointed out, to