New Conceptual Associative Learning in Amnesia: A Case Study

We report two experiments in this article that were designed to investigate the role of retrieval constraints and interference in implicit learning of new verbal associations in a densely amnesic participant, C.V., who had presumably sustained medial temporal lobe damage secondary to an anoxic episode. In Experiment 1, repeatedly studied novel sentences produced significant priming with Sentence1Fragment retrieval cues that provided maximal perceptual support as well as perceptual priming for the single-word targets. However, little learning was observed when no perceptual cues were provided for the target itself with the Sentence1??? retrieval cues. In Experiment 2, the effects of intraexperimental interference were measured by examining new verbal learning under the Study-Only, Study-Immediate test, Test-Study training conditions. Unlike in the findings reported in prior studies, C.V. showed little learning with the Sentence1??? retrieval cues even under the minimal interference, Study-Only, condition. Together, these results demonstrate that implicit access to novel verbal associations at a level more abstract than their perceptual configurations is not ubiquitously observed in dense amnesia even when the learning conditions are optimized. These results provide a window into the processes that mediate implicit learning of novel verbal associations when the explicit memory contribution is minimized. © 2000 Academic Press