The emotional counting stroop paradigm: a functional magnetic resonance imaging probe of the anterior cingulate affective division

Background: The emotional counting Stroop (ecStroop) functional magnetic resonance imaging (fMRI) activation paradigm was designed to recruit the anterior cingulate affective division (ACad). Methods: Nine normal, healthy male and female subjects (mean age 24.2 years) reported via button press the number of neutral and negative words that appeared on a screen while reaction time and fMRI data were acquired. Results: We observed a) greater ACad activation for negative versus neutral words during initial presentation blocks; b) lower overall ACad signal intensity during task performance (i.e., both negative and neutral words) compared to the baseline fixation condition; and c) no reaction time increase to negative versus neutral words. Conclusions: In a companion study of a cognitive version of the counting Stroop (Bush et al 1998), these same 9 subjects a) activated the more dorsal anterior cingulate cognitive division; b) also showed the overall decrease in ACad signal intensity; and c) demonstrated a reliable reaction time effect. Taken together, these data offer a within-group spatial dissociation of AC function based upon information content (i.e., cognitive vs. emotional) and/or presence of behavioral interference. We propose that the ecStroop will be a useful fMRI probe of ACad function in anxiety disorders.