【作者】 陈光华；

【导师】 方俊明；

【作者基本信息】 华东师范大学 ， 特殊教育学， 2009， 博士

【摘要】 模仿是社会学习的重要方式,相关研究表明,理解和模仿他人行为是人类社会认知极为重要的组成部分,但也是自闭症谱系儿童的薄弱环节。本研究在梳理国内外相关研究资料的基础上,通过三个系列的实验,逐步深入地探讨了自闭症谱系模仿的行为特征、认知功能、神经基础;并根据这些实验研究结论,针对性地开展了早期干预的个案研究,探讨交互模仿训练方法对于提高自闭症模仿能力的可行性和有效性,从而初步验证基础实验研究的结论。研究共分为五个部分:第一部分是文献综述,回顾了模仿问题和自闭症模仿缺陷的研究背景,尤其是比较了对模仿概念不同界定,模仿内涵和外延变化、研究方法的更新等问题。在分析研究背景的基础上,提出了自己的整体设想和规划。第二部分是实验研究,也是本研究的核心部分,包括三个系列共10个实验。研究被试包括15名自闭症谱系儿童、13名年龄和语言智商匹配的弱智儿童、13名年龄和非语言智商匹配的聋童。实验系列一从行为观察的角度,通过2种类型(反应部位、目标导向)的4个(手部模仿、面部模仿、驭物模仿、目标导向模仿)行为任务,考察了自闭症与弱智、聋童的表现,实验结果表明:(1)自闭症谱系儿童手部模仿能力明显落后聋童,略高于弱智儿童,但差异没有达到显著水平;(2)自闭症儿童面部模仿能力明显落后聋童,且显著高于弱智儿章;(3)自闭症谱系儿童驭物模仿能力明显落后于弱智儿童、聋童,且差异均十分显著;(4)自闭症谱系儿童的驭物—目标导向动作模仿能力显著差于聋童,但也显著高于弱智儿童;手指一目标导向动作模仿能力明显落后聋童,略高于弱智儿童。实验系列二从认知功能的角度,通过3个实验任务比较了自闭症儿童与弱智、聋童在共同注意、工作记忆、动作运用能力三项认知变量上的差异,并分析了模仿能力与这三个变量之间的关系。实验结果表明:(1)自闭症儿童的共同注意能力没有显著损伤;(2)自闭症儿童没有工作记忆的障碍;(3)自闭症儿童具有显著的动作运用障碍;(4)多元回归分析的结果表明,年龄和动作运用能力可以解释自闭症儿童模仿缺陷原因的82.8%。实验系列三从神经机制的角度,通过3个实验任务(手的动作观察与动作模仿、面部动作观察、有意义和无意义手部动作观察),采用脑功能成像的方法,检查自闭症儿童和正常成人在大脑皮层的激活情况。实验结果表明:(1)在手部观察和模仿任务中,自闭症的镜像神经系统的脑区激活和利用水平显著低于正常被试;(2)在面部动作观察期间,自闭症儿童的镜像神经系统的激活和利用水平均明显低于正常被试;(3)在有意义和无意义的肢体动作观察任务中,自闭症的镜像神经系统的激活和利用水平均明显低于正常被试。论文的第三部分是多重干预的实验研究,通过对4位自闭症幼儿的早期干预研究结果表明,四个月的干预使所有儿童在其自发的驭物模仿成绩上都取得了提升。加入干预计划越早儿童,越容易在其自发的驭物模仿方面取得了实质性的成果,这些成果保持在干预移除之后,并在与家长探索的家庭情景中得到泛化。在一定程度上,驭物动作模仿训练导致了其他社会交流的行为的共变,自发语言,假装游戏,共同注意的增加,刻板行为数量的减少。论文的第四部分对总的实验结果进行综合分析,分别从模仿缺陷的行为水平、原因机制、干预绩效三个方面,客观地讨论了如下问题:自闭症模仿缺陷是发展的延迟或先天的缺陷、智商与模仿之间的关系、模仿缺陷与社会动机缺乏之间的关系、回声性语言、重复性行为与模仿缺陷之间的关系;并试图从两个神经认知科学理论(直接匹配理论、双路线加工理论)的发展构架中,重新认识四个主要认知理论(AIM理论、自我—他人投射理论、目标导向理论、双路线理论)和模仿干预训练取得成效的原因。第五部分归纳了本研究的主要结论,并对今后研究前景提出了展望。(1)模仿缺陷是自闭症谱系儿童这一广泛性发育障碍的重要缺陷之一;(2)相对于共同注意和工作记忆的作用,年龄和动作运用的因素是影响自闭症模仿成绩的主要因素;(3)在所有动作观察任务中,正常被试的前运动区和顶下皮质都有相似的激活,首次在中国人的脑成像中,验证了镜像神经系统存在的假说;(4)自闭症儿童在所有实验任务中,都表现出镜像神经系统的激活,但其利用水平均明显低于正常被试,支持了自闭症谱系儿童模仿缺陷的镜像神经系统机能协调障碍的假设;(5)鉴于镜像神经系统回路在人类社会认知中的重要作用,自闭症包括模仿缺陷在内的更多社会认知缺陷可能与镜像神经系统相关的更复杂的,分布式网络的脑功能区异常有关。(6)交互模仿训练对于提高自闭症幼儿驭物动作模仿技能的有效性提示我们,后天的模仿训练有可能从神经可塑性的角度,改善镜像神经系统的功能协调,从而有助于自闭症谱系儿童模仿能力的提高。今后研究需要进一步解决的问题是:(a)制定标准化的模仿能力检查量表,增加更大样本的自闭症被试和其他障碍群体之间的行为比较研究,探讨从医学和生物反馈的角度对于自闭症模仿缺陷进行诊断和治疗的可能性。(b)加强自闭症谱系的更多社会认知缺陷的行为研究与神经科学研究;增加自闭症谱系的模仿缺陷与社会认知缺陷之间关系的理解;(c)强化家长和同伴在自闭症早期交互模仿训练中的作用。更多还原

【Abstract】 Imitation is a very important way to learn within a social context. Researches increasingly suggest that understanding and imitating other people’s actions is central to the development of social cognition, however, that is the weakest link to the individuals with autism. Based on the overview of many research documents related to Autistic spectrum disorder, we focus on the behavior characteristics, cognitive functions and neural mechanism during IMITATION by 3 series of experiments. Following the experiments’ conclusion, this study carried out early intervention programs for the young children with autism to assess the benefit of the Reciprocal Imitation Skills to increasing their imitative behavior, and demonstrated the validity of experimental studies in return.There are five parts within this dissertation:The first part reviewed the research background about the imitation and the impaired imitative skills related to autism, especially comparing the difference of Imitation definitions, the changes in the research approaches, then, put forward our research overall idea and design.The second part is made up of experimental studies, the core of this research, including three series of studies and 10experiments. Subjects were fifteen Children (mean age=8.40y) diagnosed with Autistic spectrum disorder (ASD), matched with thirteen Children (mean age=9.44y) diagnosed as Mental Retardation (MR) on verbal IQ and CA(Chronological Age), and thirteen Children (mean age=9.08y) diagnosed as Deaf (D) on the non-verbal IQ and CA.From the view of observing behavior, Series 1 examined their responses on the tasks categorized on 2 imitation types(response agents and Goal-directed) and 4 kinds of motor imitation (manual postures, oral-face postures, object involved action and Goal-directed action).We concluded that: (1) the individuals with ASD achieved significantly lower scores in the manual gesture imitation than the Deaf, and little higher than the MR ; (2) Children with Autism achieved significantly lower scores in oral-face postures than Deaf Children, though higher than the MR; (3) the children with ASD achieved significantly lower scores in the object involved imitation than those who were MR and Deaf; (4) Autism has goal-directed imitation deficit and failed to understand other’s action.From the standpoint of cognitive function, Series 2 analyzed the relationship between three imitation tasks (manual, oral-facial, and object oriented imitations) and three influencing factors(Joint Attention, Working Memory and Apraxia), the outcome indicated that: (1) the ability of Joint attention for individuals with ASD is intact; (2) the working memory has no influence on the imitation deficit with ASD; (3) the Dyspraxia is one of the primary reason for the Autism’s imitation deficit, but not the only one; (4) Multiple Regression Equation applied and suggested that imitation skills were differentially impaired in children with autism, the poor performance of imitation skills clustered with overall developmental level(age) and apraxia.From the perspective of neural mechanisms, Series 3 devised three tasks with different effectors (observation and imitation of the game Rock_Paper_Scissors, observation of oral-face posture, and observation of Meaningful and Meaningless limb posture). Functional magnetic resonance imaging (fMRI) scanning protocol was used to localize brain areas that were active during the observation and imitation of actions made by another individual. We found that: (1) During the observation and imitation of hand geusture, the activity attributable to MNS was less extensive in the individual with autism than normal subjects; (2) On the task of oral-face observation, the activity attributable to MNS was less extensive in the children with autism than normal subjects; (3) when observing the Meaningful and Meaningless body gesture, the activity of MNS was less extensive in Autism than normal subjects, either.The third part is the early intervention program that is multiple-baseline designed across 4 young children with autism (mean age=49.25m). In sum, after four months intervention, all participants increased and maintained their spontaneous object imitation skills and generalized in the familty. Who attend the intervention earlier; he achieved the higher performance on the object imitation easiler. To some extent, participants exhibited increases in other social-communicative behaviors, including spontaneous language, joint attention, pretend play; and the stereotypical behaviors decreased.Based on the four level of imitation, behavior characteristics, ognitive and neural mechanism nature and intervention performance, the fourth part discusses the following problems objectively: the distinction between the developmental DELAY and the congenital DEFICIT, the relationship between IQ and imitative ability, the relationship between the poor imitation performance and social motivation lacking, the connection between Echolalia and Echopraxia in autism and imitation deficit. More importantly, within the frame of the TWO neural cognitive science theories, Direct Mapping and the Dual Route Procession, we need to reconsider the FOUR primary cognitive theories, which are the theory of Active Intermodal Matching (AIM), the theory of Self-Other Mapping, Goal-Directed Imitation Theory (GOADI), the Dual Route theory, and the reason for the effecitivity of the imitation intervention training.The fifth part draws five important conclusions and predicts the research tendency. The conclusions are as follows: (1) Imitation deficit was one of main characteristic of the individual with autism, the Pervasive Developmental Disorder; (2) Comparing the role of Joint attention and Working memory, age and dyspraxia are the primary factors influencing the poor imitation performance of the children with autism; (3)During all the observation tasks, the premotor cortex and inferior parietal cortex have the same activation in Normal subjects , which are also somatotopically organized. Thus, this is the first time to demonstrate the hypothesis of MNS lied in Chinese people; (4) In whatever observation or imitation, we found that activity attributable to MNS was less extensive in the children with autism than normal subjects, which supports the hypothesis of dysfunctional Mirror Neuron System; (5) Considering that the circuit of MNS plays an important role in social cognition, we suggest that the social disability consisting of imitation deficit happening in the children with ASD is associated with altered patterns of brain activity. It is more likely to be the more complex and distributed network linking the mirror neuron system that is functionally impaired. (6) On the point ot neural plasticity, since Reciprocal Imitation Training is effective to improve the object imitation skill for the young children with autism, which suggested that the imitation skills acquired from training is helpful to improve the funcational coordination of MNS, and therefore deepen the possibility of improving imitation performance.More studies can developed in the future areas: (a) Formulating the standard imitation scale, increasing the size of subject sample, to compare autism and other developmental disability on the level of behavior characteristics, and to find the way to diagnose and treat the imitation deficit on the level of medical and biological feedback; (b) Increasing the studies on the disability of social cognition in autism, together with behavior level and neural science, and clarifying the relationship between imitation deficit and social cognition impairment; (c) Reinforcing the role of parents and peer imitation in the early intervention of reciprocal imitation training.更多还原