NEUROANATOMICAL CORRELATES OF VERIDICAL AND ILLUSORY RECOGNITION MEMORY - EVIDENCE FROM POSITRON EMISSION TOMOGRAPHY

Memory distortions and illusions have been thoroughly documented in ps ychological studies, but little is known about the neuroanatomical cor relates of true and false memories. Vivid but illusory memories can be induced by asking people whether they recall or recognize words that were not previously presented, but are semantically related to other p reviously presented words. We used positron emission tomography to com pare brain regions involved in veridical recognition of printed words that were heard several minutes earlier and illusory recognition of pr inted words that had not been heard earlier. Veridical and illusory re cognition were each associated with blood flow increases in a left med ial temporal region previously implicated in episodic memory; veridica l recognition was distinguished by additional blood flow increases in a left temporoparietal region previously implicated in the retention o f auditory/phonological information. This study reveals similarities a nd differences in the way the brain processes accurate and illusory me mories.