The relation between MRI neuroactivation changes and response rate on a word-fluency task.

This study investigated the functional magnetic resonance imaging response of the left premotor cortex activated during a word-fluency task. We hypothesized that a cortical region crossing the boundary between Brodmann's areas 44 and 6 would show bias toward output during word generation (i.e., the more words generated the greater the activation), supporting the view that this region is involved in the motor planning of speech rather than the search component of word generation. Ten participants were shown letters with different word-generational frequencies, and these were correlated with magnetic resonance signal changes over the region. Significant differences (p = .05) were found in the neuroactivation changes between groups of letters associated with high and low overt frequencies. This finding supports our hypothesis concerning the role of areas 44 and 6 in word-generation tasks.