The neurobiology of cognitive control in successful cocaine abstinence

Abstract

Introduction: Extensive evidence demonstrates that current cocaine abusers show hypoactivity in anterior cingulate and dorsolateral prefrontal cortex and respond poorly relative to drug-naïve controls on tests of executive function. Relatively little is known about the cognitive sequelae of long-term abstinence in cocaine addicts.

Methods: Here, we use a GO-NOGO task in which successful performance necessitated withholding a prepotent response to assay cognitive control in short- and long-term abstinent cocaine users (1-5 weeks and 40-102 weeks, respectively).

Results: We report significantly greater activity in prefrontal, cingulate, cerebellar and inferior frontal gyrii in abstinent cocaine users for both successful response inhibitions and errors of commission. Moreover, this relative hyperactivity was present in both abstinent groups, which, in the presence of comparable behavioral performance, suggests a functional compensation.

Conclusions: Differences between the short- and long-abstinence groups in the patterns of functional recruitment suggest different cognitive control demands at different stages in abstinence. Short-term abstinence showed increased inhibition-related dorsolateral and inferior frontal activity indicative of the need for increased inhibitory control while long-term abstinence showed increased error-related ACC activity indicative of heightened behavioral monitoring. The results suggest that the integrity of prefrontal systems that underlie cognitive control functions may be an important characteristic of successful long-term abstinence.

Figure 1

Regions in the left and right inferior frontal gyrii for STOPS analysis. Group-wise differences are shown in the charts. Error bars represent standard error of the mean.

Figure 2

Three regions, located in RMFG, and two in RSFG, used in the aggregate STOPS DLPFC cluster, the mean activity in which was aggregated and weighted by volume. Error bars represent standard error of the mean.

Figure 3

Four regions, located in left and right cingulate gyrii, used in the aggregate ERROR cingulate gyrus cluster, the mean activity in which was aggregated and scaled by volume. Error bars represent standard error of the mean.