Functional magnetic resonance imaging (FMRI) experiments frequently
administer substantially adapted cognitive tests. This study was designed
to identify FMRI correlates of a well-standardized clinical measure
presented with minor adaptations. We administered the WAIS–III
Symbol Search (SS) and a visuospatial control task to fifteen adults
during FMRI. SS-related brain activity was identified, followed by
analyses of activity related to performance level. Compared to the control
task, SS was associated with greater activity in bilateral medial
occipital, occipitoparietal, occipitotemporal, parietal, and dorsolateral
prefrontal cortices (DLPFC). Across both tasks, slower processing speed
was also related to greater activity in these areas, except right DLPFC.
Greater activity in left DLPFC was specifically related to slower
processing speed during SS. Performance was consistent with education
levels. Findings suggest that SS performance involves regions associated
with executive and visual processing. Furthermore, slower SS performance
was related to greater recruitment of left hemisphere regions associated
with executive function in other studies. (JINS, 2005,
11, 471–476.)