This work uses the well-established (by PET) confrontation naming task to compare PET and fMRI in a cognitive activation experiment. The signal changes from this task are much less than the changes caused by visual or motor activation tasks used in previous comparisons. ANOVA methods adjusted for multiple comparisons were used to determine significant changes in signal between confrontation naming and figure size discrimination tasks. All 17 significantly increased regions (confrontation naming signal greater) seen on one modality were increased on both modalities. Ten of 13 regions that were significantly decreased on one modality were decreased on the other. Three mismatched regions showed a significant decrease on one modality and a nonsignificant increase on the other. This study could not detect a consistent difference in activation site location between PET and fMRI.
Bibliographical noteFunding Information:
The authors gratefully acknowledge the thoughtful discussions and review of the manuscript by Roger P. Woods of the Neurology department of UCLA. The PET portions of this work were supported by NIH Grant MH53467 and the Emory University center for PET. The authors also acknowledge Egleston children’s Hospital for use of the MRI scanner, the Fritz Phillips Center for assistance, and the University Research Council of Emory University.