Role of the anterior temporal lobe in repetition and semantic priming: evidence from a patient with a category-specific deficit.

Neuroimaging studies in healthy participants have implicated anterior temporal lobe regions and the fusiform gyrus in repetition priming and semantic priming. Only the investigation of patients with selective lesions, however, can establish the necessity of these particular regions. To this end, we administered three tests of repetition priming (pseudoword identification; masked-form priming; category-exemplar generation) and a test of semantic priming to a patient (J.P.) with a category-specific deficit stemming from bilateral damage to the anterior fusiform gyrus and anterior temporal regions. On all of the repetition priming tasks, J.P. showed priming effects within 1 S.D. of 10 age- and education-matched CON; ANOVAs indicated no interaction between group and prime condition. These findings suggest that the anterior fusiform and anterior temporal lobe are not required for these priming effects. J.P. also showed normal repetition priming even for items that he had never been able to name or to provide semantic information about. On the semantic priming task, J.P. showed normal levels of priming across categories. When we separately analyzed his priming for items he could never name or access information about versus items that he had been able to name on at least two testing sessions, we found priming for the latter items, but not for the former. This result suggests that category-specific deficits resulting from damage to the anterior temporal lobes may disrupt the automatic, rapid access of semantic information of some items.