Background: Chronic stimulant use has been associated with disruptions in fronto-striatal systems implicated in as- sociative learning [1]. Experimental studies have also shown that individuals with stimulant drug addiction experience difficulties in selecting the appropriate action following feedback [2]. However, the precise impairments in feedback learning in stimulant-addicted individuals are still unclear. A possible explanation might lie in an abnormal prediction error mechanism, as stimulant drugs directly target striatal dopaminergic neurons [3].