RECENCY EFFECT IN ANTEROGRADE AMNESIA - EVIDENCE FOR DISTINCT MEMORY STORES UNDERLYING ENHANCED RETRIEVAL OF TERMINAL ITEMS IN IMMEDIATE AND DELAYED RECALL PARADIGMS

This study was devised to investigate immediate and delayed recency ef fects in anterograde amnesic patients. For this purpose, a word-list i mmediate recall paradigm and a modified version of the procedure devis ed by Baddeley and Hitch [Attention and Performance, Erlbaum, NJ, 1977 ] for eliciting the recency effect in delayed recall conditions was ad ministered to a sample of amnesic patients and to a group of age-match ed healthy subjects. Amnesics disclosed a fully normal recency effect in the immediate recall paradigm and a deficient recency effect in the delayed recall condition. These data, taken together with experimenta l evidence from a patient affected by a pure form of phonological shor t-term memory impairment [35], draw a double neuropsychological dissoc iation suggesting a differential origin for the two kinds of recency e ffects: a short-term memory output underlying enhanced recall of termi nal items in immediate recall paradigms, and an ordinal retrieval stra tegy applied to long-term memory stored units at the root of the delay ed recency effect.