An fMRI study on the dorsal attention network of heroin addicts and heroin abstainers / 中华行为医学与脑科学杂志

ABSTRACT

Objective To explore the functional imaging alteration of dorsal attention network (DAN) between heroin addicts and heroin abstainers and probe into its influence on attentional function.Methods Attention-related neuropsychological assessments were applied to evaluate the difference of attentional function between heroin addicts and heroin abstainers.With the functional magnetic resonance imaging (fMRI) data obtained from 17 heroin addicts and 15 heroin abstainers at resting state,we extracted the DANs of heroin withdrawal group and heroin dependence group respectively by using independent component analysis (ICA) and analysed the differences of intra-group and inter-group,then correlation analysis was performed among brain areas which have significant difference between groups and Stroop interference effect test.Results Compared with the heroin dependence group,there was a better result of attentional function in the heroin withdrawal group (P＜0.05),especially at the digit span test(backward) (P=0.0363),digit symbol test (writing) (P =0.0195),Stroop test C (reaction) (P =0.0379),Stroop test C (error) (P=0.0014) and Stroop interference effect test (P=0.0002).Neuroimaging findings demonstrated that there was a similar DAN in the heroin withdrawal group and heroin dependence group which mainly included the bilateral intraparietal suleus,postcentral gyrus and frontal eye field.Compared with the DAN of heroin addicts,significantly enhanced functional connectivity within the DAN of heroin abstainers was observed in the left superior parietal lobule (MIN-24,-75,48),right inferior parietal lobule (MIN39,-54,45) and left inferior parietal lobule (MIN-33,-51,57).Significant negative correlations were observed between these brain areas and Stroop interference effect test in the heroin dependence group (r=-0.79,-0.69,-0.64,P＜0.01),but not in the heroin withdrawal group.Conclusions Heroin addiction can impair attentional function,compared with the DAN of heroin addicts,significantly enhanced functional connectivity in the left superior parietal lobule as well as bilateral inferior parietal lobule are observed in the heroin abstainers at resting state,which may be one of the neural mechanisms of attentional function improvement.