| The current study examined the relationship of MRI integrity with neuropsychological measures of letter and semantic fluency. Two proposals have suggested the potential neural dissociability of the frontal and temporal lobe systems which mediate letter and semantic fluency (Moscovitch, 1994) and switching and clustering (Troyer, 1997), two sub-indices that underlie successful fluency performance. This study compared the performance of patients with temporal lobe epilepsy (TLE) and healthy controls on letter and semantic fluency tasks, and on indices of clustering and switching. As predicted, TLE patients performed more poorly on all fluency measures compared to controls, with greater impairment on semantic fluency compared to letter fluency. Study hypotheses regarding the neural dissociability of the different fluency measures in the TLE group was not supported. |
