研究背景與目的:自閉症類群疾患與注意力缺失/過動症(ADHD)有許多相似的特徵,這些相似處可能影響臨床工作者的鑑別診斷,甚至誤診或延誤治療。除了部分的外顯行為症狀相似之外,過去的研究也指出兩者皆有工作記憶(working memory)的缺陷,但受損的子系統不盡相同。近年工作記憶的研究中,常使用N-back作為測量工具之一。另一方面,近年也有學者認為ADHD有時間知覺(time perception)的缺陷,但關於AS之時間知覺的研究較少,且結果不一致。而時間知覺的研究中,時距區辨作業(time discrimination task)被認為是最能測得時間知覺的測驗之一。因此,本研究企圖比較AS與ADHD在工作記憶及時間知覺的異同,並進一步探討N-back作業及時距區辨作業是否可作為區別AS與ADHD的評估的工具。 研究方法:本研究以AS、ADHD及一般正常發展的學齡兒童(6-12歲)各31位作為研究對象,比較三組學齡兒童在字母N-back、位置N-back、數字記憶廣度作業、空間廣度板作業等工作記憶作業以及時間區辨作業的表現,以探討各組之語言工作記憶、視覺空間工作記憶、及時間知覺的能力。 研究結果:(一)三組於數字記憶廣度作業以及空間廣度板作業之結果受IQ影響,N-back作業則不受IQ影響,且較能區辨三組之差異。(二)語言工作記憶:ASD之表現皆與一般生沒有顯著差異,但ASD的表現顯著優於ADHD,且一般生有優於ADHD的趨勢。(三)視覺工作記憶:ASD與一般生無顯著差異,但ASD及一般生的表現皆優於ADHD。(四)時間知覺:本研究發現困難版時距區辨作業與工作記憶的相關較少,顯示困難版相對能測得較純的時間知覺,但仍受工作記憶影響,而三組在困難版的表現未達顯著差異。 討論:綜合而言, ASD之語言工作記憶沒有缺損,但於視空間記憶之缺損仍有爭議,而ADHD則是於語言工作記憶及視空間工作記憶皆有缺陷,且ADHD在工作記憶的缺損較AS嚴重。本研究亦發現,測量工作記憶的作業中,N-back對於AS與ADHD的區辨力較好。時間知覺方面,過去大部分的研究工具所測得的能力包含時間知覺與工作記憶,Vrabel(2009)認為在提升難度的情況下能真正評估到相對較純時間知覺的能力。本研究結果也驗證此觀點,但關於三組在時間知覺的差異,仍有待未來研究進一步釐清。
Objectives: There are many similar characteristics between Autism Spectrum Disorder (ASD) and Attention deficit/ hyperactivity disorder (ADHD), these similarities might affect clinicians as making differential diagnosis, even misdiagnosed or delayed treatment. Not only overt behavior symptoms, they both have working memory deficits, but defect in different componets. In these years, the N-back is one of the most useful tasks to assess working memory. On the other hand, recent studies reported that children with ADHD have manifest deficits in time perception, but few studies have been done on children with AS in time percpetion, also the results were inconsistent.The studies about time perception indicated that the time discrimination task might be one of the tasks that can assess pure time perception. Therefore, the main purpose of this study was to evaluate group differences on working memory and time perception in children with AS, ADHD, and controls, as well as to examine the validity of using the N-back and time discrimination task to diagnosis children with ASD and ADHD. Methods: 93 childrn in three groups of ASD, ADHD and normal children, who were 6 to 12 year-old, were included. To investigate their abilities of verbal and spatial working memories and time perception, the study used the letter n-back task, the digit span task, the visual-spatial n-back task, the span board task, and the time discrimination task. Results: The result showed that, IQ may affect the results of span tasks, but not N-back. Secondly, for the verbal working memory, the performances of children with ASD were same as control but better than children with ADHD. Third, for the visualspatial working memory, no significant differences were found between ASD and control, but perfomance of children with ADHD was both worse than control and ASD. Forth, there were no significant differences between ASD, ADHD and control in time discrimination task. Discussion: In general, both ASD doesn’t have verbal working memory deficits, but there still have controversial issue in performance of children with ASD in visual-spatial working memory. On the other hand, ADHD have deficits in visual-spatial working memory deficits and verbal working memory, the WM ability of children with AS was better than that of children with ADHD. Furthermore, the study also found out that, using the N-back may distinguish ADHD and ASD more superiorly. On the other hand, most tasks used in the studies about time perception had measured not only time perception, but working memory, Vrabel (2009) concluded that, increasingly difficult time discrimination items would require participants to rely more on their sense of time, this study proofed his aspect. However, the ability of time perception of children with ASD and ADHD still need more experimental data to test and verify.