Both effects have been discussed as effects of fluency.
In Experiment 3, we demonstrated that the effects of fluency can be reversed when a salient attribution for reduced fluency is available (i.e., the stimuli are hard to read because they were printed by a printer with low toner).
In this analysis, we modeled the effects of fluency in L1 and L2 separately and included the scores from Raven's matrices as an additional regressor to control for general cognitive effects that are known to be correlated with overall fluency ability.
Across both studies, dopamine increased fluency but diminished overall uniqueness of options generated, due to the effect of fluency trading off with uniqueness.
The effects of overall fluency, summed over fluency type (semantic and phonemic).
We then conducted 2 statistical analyses that identified correlations between the gray matter density and the following: The effects of overall fluency, summed over fluency type (semantic and phonemic).
An ANOVA was used to examine the effects of verbal fluency (COWAT performance) on systolic blood pressure.
Moreover, the indirect effects of ideational fluency (β = .15, p < .01) and originality (β = .17, p < .05) were significant, too.
The main effect of verbal fluency revealed activation in a distributed network of regions that is well associated with word production [ 12], encompassing the bilateral inferior frontal and insular cortices, left superior temporal cortex, thalamus, and the dorsal anterior cingulate cortex which showed a greater response for the more difficult letters.
In terms of the effects of language on fluency, there was no effect of L1 versus L2 on phonemic fluency, mean = 14.9 and 15.7, respectively, F < 1.
In terms of the effects of a nonverbal fluency (RFFT performance) measure on systolic blood pressure, main effects were found for trial [F 1,54) = 16.67, p = .000] and anger expression style [F 1,54) = 4.30, p = .04], both in the hypothesized direction.
