Abstract
We report the performance in four recognition memory experiments of Jon, a young adult with early-onset developmental amnesia whose episodic memory is gravely impaired in tests of recall, but seems relatively preserved in tests of recognition, and who has developed normal levels of performance in tests of intelligence and general knowledge. Jon's recognition performance was enhanced by deeper levels of processing in comparing a more meaningful study task with a less meaningful one, but not by task enactment in comparing performance of an action with reading an action phrase. Both of these variables normally enhance episodic remembering, which Jon claimed to experience. But Jon was unable to support that claim by recollecting what it was that he remembered. Taken altogether, the findings strongly imply that Jon's recognition performance entailed little genuine episodic remembering and that the levels-of-processing effects in Jon reflected semantic, not episodic, memory.
We are grateful to Jon and to his parents for their very willing cooperation. This research was supported by the Economic and Social Research Council (ESRC Grant R000223887). It was also supported in part by the Intramural Program of the NIMH/NIH, and we thank them both for their support. We also thank Bo Molander for providing the materials and norms for the action phrases used in the self-performed tasks.