Authors:
Sharon L. Thompson-Schill
Diane Swick
Martha J. Farah
Mark D'Esposito
Irene P. Kan
Robert T. Knight
Date: 1998
PubMed: 9861060
Abstract:
What are the neural bases of semantic mem- ory? Traditional beliefs that the temporal lobes subserve the retrieval of semantic knowledge, arising from lesion studies, have been recently called into question by functional neuro- imaging studies finding correlations between semantic re- trieval and activity in left prefrontal cortex. Has neuroimag- ing taught us something new about the neural bases of cognition that older methods could not reveal or has it merely identified brain activity that is correlated with but not caus- ally related to the process of semantic retrieval? We examined the ability of patients with focal frontal lesions to perform a task commonly used in neuroimaging experiments, the gen- eration of semantically appropriate action words for concrete nouns, and found evidence of the necessity of the left inferior frontal gyrus for certain components of the verb generation task. Notably, these components did not include semantic retrieval per se.