Lower activation in the right frontoparietal network during a counting Stroop task in a cocaine-dependent group

Abstract

Dysregulation in cognitive control networks may mediate core characteristics of drug addiction. Cocaine dependence has been particularly associated with lowactivation in the frontoparietal regions during conditions requiring decision making and cognitive control. This functional magnetic resonance imaging (fMRI) study aimed to examine differential brain-related activation to cocaine addiction during an inhibitory control paradigm, the “Counting” Strooptask, given the uncertainties of previous studies using positron emission tomography. Sixteen comparison men and 16 cocaine-dependent men performed a cognitive “Counting” Strooptask in a 1.5 T Siemens Avanto. The cocaine-dependent patient group and the control group were matched for age, level of education and general intellectual functioning. Groups did not differ in terms of the interference measures deriving from the countingStrooptask. Moreover, the cocaine-dependentgroup showed loweractivation in the right inferior frontal gyrus, the right inferior parietal gyrus and the right superior temporal gyrus than the control group. Cocaine patients did not show any brain area with increased activation when compared with controls. In short, Stroop-interference was accompanied by loweractivation in the rightfrontoparietalnetwork in cocaine-dependent patients, even in the absence of inter-group behavioral differences. Our study is the first application of acountingStrooptask using fMRI to study cocaine dependence and yields results that corroborate the involvement of afrontoparietalnetwork in the neural changes associated with attentional interference deficits in cocaine-dependent men.