Independent Functioning of Verbal Memory Stores: A Neuropsychological Study

Five experiments are described concerning verbal short-term memory performance of a patient who has a very markedly reduced verbal span. The results of the first three, free recall, the Peterson procedure and an investigation of proactive interference, indicate that he has a greatly reduced short-term memory capacity, while the last two, probe recognition and missing scan, show that this cannot be attributed to a retrieval failure. Since his performance on long-term memory tasks is normal, it is difficult to explain these results with theories of normal functioning in which verbal STM and LTM use the same structures in different ways. They also make the serial model of the relation between STM and LTM less plausible and support a model in which verbal STM and LTM have parallel inputs.