Behavioral evidence suggestive of frontal lobe pathology in the amnesic H.M.

From the earliest published reports, Henry Gustav Molaison-who until his death in 2008 was known simply by his initials H.M.-was characterized as having a profound anterograde amnesia subsequent to mid temporal lobe resection, and that this amnestic condition was uncomplicated by other cognitive or behavioral impairments. Post-mortem neuropathological examination has detected-in addition to the expected temporal lobe lesions-previously unreported frontal lobe and white matter pathology, inviting questions concerning the behavioral and cognitive consequences that might result from such lesions. The purpose of this article is to recount published descriptions of a range of anomalous behaviors by H.M. that can not be explained by the memory impairments typically associated with anterograde amnesia, to counter previous claims that these behaviors are attributable to amygdalar damage, and to advance the interpretation that these behaviors are instead consistent with well-documented effects of frontal lobe pathology. Transcripts of interviews with H.M. which feature disjointed, often contradictory, and arguably confabulatory responses are presented in support of this argument.