Semantic knowledge and episodic memory for faces in semantic dementia

Previous studies have documented poor recognition memory for faces in patie nts with semantic dementia. Preserved face recognition memory was found in this study, however, so long as atrophy was confined predominantly to the l eft temporal lobe. Patients with structural damage to the right temporal lo be were typically impaired, with the status of the hippocampus and parahipp ocampal gyrus (including the perirhinal cortex) on the right being critical . Two single-case studies of patients with predominantly left temporal lobe pathology confirmed good recognition memory for famous faces, even if sema ntic knowledge about the celebrities depicted was severely degraded. An eff ect of semantic knowledge on recognition memory became apparent only when p erceptually different photographs of the famous people were used at study a nd test. These results support the view that new episodic learning typicall y draws on information from both perceptual and semantic systems.