Multiple memory systems: evidence from stroke.

In this report, we describe the "fractionation of memory systems" in a 62-yr.-old woman following a left anterior stroke. Despite the presence of a significant, persistent declarative memory (verbal learning) deficit, this patient exhibited relatively intact procedural learning. The latter was manifested over a 4-day period by improved performance on a maze task executed under "mirror-tracing" conditions. By the final set of trials, the patient's performance approximated that of a normal control subject with respect to speed, although not errors. The selective preservation of particular learning abilities in brain-damaged patients has implications for rehabilitative interventions.