海洛因成癮者的決策判斷與抑制控制缺損探討

本研究目的主要在探討海洛因成癮者是否具有決策判斷的問題與抑制控制能力缺損，利用數理認知模型的參數值檢驗受試者在新式Go/No-Go作業的表現，該作業結合IGT與原先Go/No-Go作業的特性，並將作業刺激改為中性與海洛因相關的圖片，探討海洛因成癮者在此作業的決策歷程與抑制反應功能，並與控制組作比較。另者，根據誘發─敏感化理論 ( Robinson & Berridge, 1993 ) 與誘發─習慣化模式 ( Di Chiara, 2000 ) 的預測，前者認為成癮越嚴重者的抑制缺損情形會越嚴重，對藥物相關刺激的注意力偏誤也越明顯；後者則認為藥物依賴階段的初期會發生較嚴重的注意力偏誤情形，但隨著依賴程度增加而對藥物相關刺激已習慣化，尋求藥物行為也已變成自動化反應，故注意力偏誤的情形反而會減少。因此，本研究試圖在加入藥物相關刺激的Go/No-Go作業中驗證這兩種理論的預測。 本研究以48位一般控制組、88位海洛因受戒治人為樣本，利用Go/No-Go作業與線索依賴學習模式 ( CD model ) 分析受試者對酬賞或處罰的注意力 ( w參數 )、學習率 ( 參數 )、反應一致性 ( c參數 )、以及海洛因圖片價值的影響 ( I_Heroin參數 )，結果發現，比起控制組，海洛因成癮者對酬賞的注意力較低、受到藥物相關刺激影響較明顯。另外，將戒治組分為物質高依賴組與低依賴組時，比起控制組，高依賴組對酬賞的注意力較低；而低依賴組受到海洛因圖片價值影響較明顯。結果證實當面對同時具有中性與藥物相關刺激時的情況下，海洛因成癮者與過去古柯鹼成癮者在決策作業上的表現不同，不僅受到酬賞或處罰的影響，藥物相關刺激本身亦帶有某種價值，影響成癮者的決策與抑制能力；另外，結果部分支持誘發─習慣化的預測。

The purpose of present study was to investigate the decision making and inhibitory problem in heroin addicts, and to use the mathematics cognitive model parameters to examine performance in a new Go/No-Go Task of subjects. The task combined the characteristics of IGT and original Go/No-Go Task. We changed the task’s stimuli to neural and heroin related pictures, to explore the decision making and inhibitory reactive function in the task, and compared with control group. On the other hands, according to Incentive-sensitization theory (Robinson & Berridge, 1993) and ‘Incentive ─ habit’ model (Di Chiara, 2000), the incentive-sensitization thoery thought that people with increasing severity of addiction get more inhibitory problems and attentional bias toward drug related cues, but the incentive-habit model suggests that attentional bias for drug cues will be more severe in the early stage of drug dependence., but with the increase in dependence and habit to drug cues, drug-seeking behavior has become automatic reaction, so attentional bias will be attenuated when abusers get more dependence. Therefore, this study attempted to verify the prediction of two theories in the Go / No-Go Task with drug-related stimuli. This research was based on the data collected from the 48 normals and 88 heroin addicts, using Go/No-Go Task and Cue-dependence learning model ( CD model ) analysis their attention to reward or punishment ( parameter w ), learning rate ( ), reactive consistence ( c ), and valence of heroin pictures ( I_Heroin). The result revealed that compare to controls, heroin addicts had fewer attention to rewards, and more obvious influenced by drug related stimuli. Otherwise, to divided addicts group into high dependence group and low dependence group, compared to control group, the high dependence addicts had lower attention to reward, and the lower dependence addicts was higher influenced by drug related stimuli. It confirm that when heroin abusers faced to neural and drug related stimili, their performance in decision making task was different from cocaine abusers, it’s not only influenced from reward or punishment, but also from the valence of drug related cues. In addition, the result partially support the prediction of the incentive-habit model.