Ever since patient H.M.s medial temporal lobe resection, the hippocampus is believed to play an important role in declarative memory. However, more recent results in humans and monkeys with early hippocampal lesions have questioned the specic role the hippocampus plays in episodic versus semantic memory. Neuropsychological studies have shown that adult hippocampal lesions impair episodic and semantic memory, whereas hippocampal lesions happening early in life impair episodic memory and leave semantic memory largely preserved. It has been suggested that the perirhinal and parahippocampal cortices may be crucial for semantic memory and might be able to support certain declarative memory functions following early but not late hippocampal lesions...