【作者】 杨瑒；

【导师】 邓赐平；

【作者基本信息】 华东师范大学 ， 发展与教育心理学， 2010， 硕士

【摘要】 毒品依赖问题越来越严重,它会给个体的神经系统、认知功能、社会功能等各个方面带来非常严重的后果。因此,对毒品依赖背后的认知机制,并通过分析可能的缺损情况是理解成瘾行为的有效途径。在戒除毒瘾的过程中,个体往往需要付诸很大的意志努力来克服毒瘾冲动。而克服强烈习惯性反应或抵制诱惑的情境中,个体的执行功能显得格外重要。因此,本文着重研究毒品成瘾者的执行功能特征和缺损情况,以此来分析和理解戒毒者吸毒行为背后的认知机制。虽然关于执行功能的理论和模型很多,但是本研究中所涉及的执行功能主要有抑制、注意和工作记忆能力。具体地,本研究1、采用停止信号任务,通过对比毒品成瘾者和匹配正常个体的抑制任务绩效,考察毒品成瘾者抑制控制能力的损伤情况；2、采用持续绩效任务对毒品成瘾者的持续注意和选择注意进行探求,分析其特征；此外,还采用视觉定向范式(The Visual Orienting Task, VOT)对戒毒者的内源和外源注意定向过程进行考察；3、采用经典的数字广度和语义广度对个体的数字短时记忆、数字工作记忆和语义工作记忆广度进行评估。此外,除了洞察上述三个部分的认知功能之外,本研究还试图分析不同毒品滥用者之间在缺损程度上是否存在缺损差异,且执行功能各成分的缺损程度是否存在性别差异。本研究中招募的吸毒组被试皆选自上海市强制戒毒所(男所和女所),由司法系统配合我们招募被试；根据获得的实验组被试的年龄、性别和教育水平等特征,招募本研究的对照组被试。研究表明：1、与正常个体相比,毒品成瘾者的抑制能力受损显著；男性个体在各种难度的延迟任务上均有缺损,而女性个体则相对在任务要求较高的延迟任务上缺损显著；兴奋剂依赖者的抑制缺损最严重,而海洛因依赖者和多物质滥用者缺损程度没有兴奋剂强烈,二者之间基本持平。2、与正常个体相比,毒品成瘾者的持续注意和选择注意缺损不显著,但线索注意警觉受损显著；但是持续注意和选择注意存在性别差异,且女性戒毒者CPT线索警觉绩效最差,线索没有起到促进作用而是起到抑制注意的作用；海洛因戒毒者线索警觉缺损最严重,线索起抑制注意作用,其次为多物质滥用者,其线索也存在抑制注意的现象,而最好的是兴奋剂依赖者,线索起到促进注意作用,但是促进不明显；与正常个体相比,毒品成瘾者的内源和外源注意定向过程有缺损,具体地,女性戒毒者在内源注意定向过程中缺损显著,而男性戒毒者在外源注意定向过程中受损严重；但是对于男性戒毒者来说,内源线索促进作用反而优于男性正常个体。3、与正常个体相比,戒毒者的数字短时记忆和语义工作记忆受损显著。男性戒毒者在数字短时记忆和语义工作记忆中显著低于男性正常个体,而女性戒毒者则在数字短时记忆中反而高于女性正常个体；海洛因戒毒者在工作记忆上受损最显著。4、就执行功能的三个子成分来说,效应量分析表明工作记忆受损最突出,而相对基本的认知加工——抑制和注意则受损相对较少。此外,停止信号任务,尤其是延迟时间较长的停止信号任务,和语义工作记忆对鉴别成瘾对象、以及不同毒品依赖者认知能力最为敏感。本研究期望,研究结果可以用于进一步的毒品干预和治疗中。更多还原

【Abstract】 With the increasing severity of drug dependence, it brings negative consequence in neural system, cognitive functions and social functions. Thus, acknowledge of underlying mechanism and analysis of potential impairment become the effective paths to comprehend addictive behaviors. During the process of drug abstinence, people need to pay much more efforts in overcoming addictive impulsivity. It highlights the executive functions in the condition of resisting strong habitual responses and temptation. Therefore, this study focused on the characteristics and impairments of executive functions of drug abusers, and then tried to understand the underlying mechanism of addictive behaviors.Although there are massive theories and models of executive function, this study is mainly involved in inhibition, attention and working memory. In details, this study aimed at:(1) adopting stop signal task to explore the impairments in inhibition for drug abusers by comparing the performance in both drug abusers and control people; (2) employing the visual orienting task to investigate the process of covert and overt attention orienting; (3) using digit span and semantic span tasks to evaluate the short time memory, digit working memory and semantic working memory. In addition, this study also tried to analyze the differences in impairments of executive functions between different kinds of drug abusers and between males and females.The addictive participants were recruited from correctional-based drug intervention rehabilitation cooperated by legal system. The control people were recruited according to the characteristics of age, gender and educational levels of experimental group.This study indicated that:(1) compared to the control, drug-dependent people had impaired inhibitory ability. Male drug abusers showed deficits in all inhibitive tasks and female drug abusers showed impairments in high-demanded inhibitive tasks. Among three kinds of drug abusers, the inhibition in psycho-stimulant abusers was most severe impaired, followed by heroin abusers and polysubstance abusers which the two group had the similar degree of deficits. (2) in contrast to control people, addictive people had significant impairments in alertness, especially for female abusers in which group the clues inhibited attention instead of promotion, rather than sustained attention and selective attention. For three kinds of drug abusers, both heroin-dependent and polysubstance-dependent individuals deteriorated in attention-clued alertness task whereas psycho-stimulant abusers had comparatively superior performance than the other addictive groups but still inferior to the control. Although drug abusers showed impairments in both covert and overt attention orienting process, it suggested a gender difference that male abusers had deficits in covert attention orienting and female abusers had impairments in overt attention orienting. (3) drug abusers had impaired digit short memory and semantic working memory contrary to control individuals. Specifically, male abusers had worse performance in digit short memory and semantic working memory than male control people, whereas surprisingly female abusers had better performance in digit short memory than female control people. For three kinds of drug abusers, drug dependence brought most serious damage into heroin addictive people. (4) For the three sub-components of executive functions, the analysis of effect size illustrated that the impairment in working memory is outstanding, whereas the performance in more basic processing (i.e. inhibition and attention) was relatively impaired less than that in working memory.Moreover, the stop signal task, especially longer delayed stop signal task, and semantic working memory were most sensitive to the discrimination of cognitive functions between addictive people and control people and also different types of drug-dependent individuals. The results of this study could be used in further intervention and treatment of addictive behaviors.更多还原