Dissociation Between Recall and Recognition Memory Performance in an Amnesic Patient with Hippocampal Damage Following Carbon Monoxide Poisoning

Abstract

Some patients with relatively selective hippocampal damage have shown proportionate recall and recognition deficits. Moreover, familiarity as well as recollection have been found to be impaired in some of these patients. In contrast, other patients with apparently similar damage presented with relatively preserved recognition despite having severely impaired recall, and some of these patients have been shown to have preserved familiarity. We report here the case of an amnesic patient who suffered bilateral hippocampal damage and temporoparietal atrophy after carbon monoxide poisoning. On tests matched for difficulty, his recall performance was more severely impaired than his recognition memory, for verbal as well as for visual materials. Moreover, he performed within the range of healthy matched subjects on nine recognition tests out of ten. In a task using the process dissociation procedure, the patient's familiarity was preserved although his recollection was impaired. These findings indicate that recall and recognition memory can be dissociated in amnesic patients with hippocampal lesions even when temporoparietal cortical atrophy is also present.

Acknowledgments

We are very grateful to Dr. Olivier Moreaud for allowing access to the Neuropsychology Unit facilities at the University of Grenoble, to Dr. Sylvie Grand (University of Grenoble) for MRI scan acquisition and to Vanessa Sluming (University of Liverpool) for volumetric analyses of the frontal lobes. We thank Dr. Claire Bindschaedler for providing the materials for the French version of the Calev procedure and its revision. We also thank Pr. Larry L. Jacoby and Pr. Andrew P. Yonelinas for helpful comments.

This work was supported by a grant from the French Community of Belgium: “Actions de Recherche Concertées (convention 99/04-246)”.