Summary: Using high-field (4 Tesla) fMRI, here we show that during processing of drug and matched neutral words cocaine abusers have similar accuracy and reaction times to matched controls, but lower BOLD and CM signals in the dorsal medial nucleus of the thalamus, cerebellum, and rostral anterior cingulate cortex. These findings suggest that lower recruitment of subcortical resources and impaired inhibition of cortical resources may be mediated by abnormal functional connectivity of catecholamine (dopamine, norepinephrine and serotonin) pathways in cocaine abusers. The negative correlation of the thalamic CM (and the lack of correlation with BOLD responses in the thalamus) with years of cocaine use suggests that functional connectivity might be more sensitive than standard fMRI activation techniques for the detection of subtle functional neuroadaptations associated with drug addiction.
