[Recall and clustering in a patient with memory disorders: with special reference to incidental learning]

A case study of recall and categorical clustering in the patient with organic anterograde amnesia is reported. The stimulus list involved 28 words comprising of eight categories with four items in each, which were individually typed in one-letter Kanji character on index cards. This experiment was carried out in incidental learning situation, in which the patient and normal controls were instructed to read aloud each stimulus item. In the test phase, subject was required an immediate free recall orally. Two indices were computed from the test results; the number of words correctly recalled and the level of clustering. While the patient achieved the same number of correct recalls as the controls, she failed to produce the equal level of clustering as the latter. The results suggest that categories or semantic associations were not used by the patient as retrieval cues. The dissociation between recall and clustering in the patient are discussed.