Fig. 4: Comparison of the self-mother memory task performance between abstinent heroin misusers (AHM) and healthy controls (HC).

Seventy-three abstinent heroin misusers (AHM) and sixty-four healthy controls completed the self-mother memory task, focusing on responses from the recognition memory phase. Since participants were not required to respond as quickly as possible, only accuracy (ACC) was analyzed. Consistent with Study 1, AHM displayed a reduced mother prioritization effect (MPE) compared to healthy controls. The mixed-model ANOVA, using a 3 (Reference Condition: self, mother, familiar other) × 2 (Group: AHM, healthy controls) design, revealed a significant interaction effect between Reference Condition and Group. Simple effects analyses for healthy controls showed no significant difference between self- and mother-reference effects, but both were significantly stronger than familiar-other-reference effects. In contrast, the AHM group demonstrated a self-reference advantage over both mother- and familiar-other-references, as well as a mother-reference advantage over familiar-other-reference (***p < 0.001, **p < 0.01, *p < 0.05).