Testing graceful degradation in a patient with aphasia.

We report an investigation of phonological priming of a picture naming task in an anomic aphasic, PB, using caffeine as a pharmacological manipulation. We compare her results to controls on a similar paradigm testing the hypothesis that qualitative results in controls would carry over to the damaged brain demonstrating a "graceful degradation" in performance. When primed with words phonologically related to a target, PB made more word retrieval failures on caffeine as a function of related primes (controls make fewer) and fewer word retrieval failures as a function of unrelated primes (controls make more). The results thus supported the rejection of the hypothesis and we conclude that the use of the pharmacological manipulation provides a sensitive test for the graceful degradation of function.