- 學位論文
遺傳和環境因子對於威斯康辛卡片分類表現的影響：雙胞胎�手足研究
Genetic and Environmental Influences on the Wisconsin Card Sorting Test Performance: A Twin/sibling Study
摘要
背景：威斯康辛卡片分類測驗被廣泛運用於測量執行功能，並且此功能表現與大腦額葉功能有關。精神分裂症是諸多與額葉功能缺損相關的精神疾病之一，也是最廣泛運用此測驗工具的疾病。近年來在精神疾病的分子遺傳研究中，運用內在表現型的概念尋找與疾病相關的基因。威斯康辛卡片分類測驗被認定為精神分裂症的內在表現型，但是過去文獻對此測驗表現的遺傳度未有一致性的結論。 目標：利用青少年雙胞胎樣本探討威斯康辛卡片分類測驗的表現情形。並估算遺傳和環境對此表現影響的百分比。 方法：針對397對在1996至1998年間於台北市立國中收取的雙胞胎/手足樣本進行電腦版威斯康辛卡片分類測驗。針對測驗結果所產生的各項指標分別估算成對雙胞胎手足之間的相關係數，並比較同卵和異卵雙胞胎/手足樣本之間相關系數的差異。使用結構方程模式（structural equation modeling）估計方法，估算每一項指標受到遺傳和環境影響的百分比。 結果：同卵和異卵雙胞胎/手足樣本之間的相關係數沒有顯著差異。利用結構方程模式估算結果顯示：威斯康辛卡片分類測驗表現情形遺傳可解釋的百分比很小並且未達顯著性；共享環境可解釋百分之三十的變異並達統計顯著性。 結論：由於此測驗表現未受到遺傳因子的影響，因此不建議將此測驗運用在分子遺傳的研究。若欲探討特定環境因子對認知功能的影響，威斯康辛卡片分類測驗是有效的測驗工具。
並列摘要
Objective: The Wisconsin Card Sorting Test (WCST) is a widely used measurement for assessing executive function and frontal lobe function. Among many psychiatric disorders examined for WCST performance, schizophrenia is the most extensively investigated one and has been found to have impaired performance on the WCST. To help tackle the genetic susceptibility to schizophrenia, the WCST impairment was advocated as an endophenotypic marker of the disease. However, the heritability estimates of the WCST performance were inconsistent. This study aimed to estimate the relative contributions from genetic and environmental factors to the WCST performance, and compare the differences in these contributions among different WCST indexes. Method: Participants included 397 twins and same-sex sib-pairs, aged from 12 to 16, recruited from 51 junior high schools in Taipei City between 1996 and 1998. A computerized version of the WCST was administered for each subject and its nine indexes were used for subsequent analysis. After pooling DZ twins and non-twin sib-pairs, univariate analysis of structural equation modeling was performed for each WCST index using Mx program. Results: The correlations of the WCST performance scores between MZ and DZ/SP groups were not significantly different. ACE model for each WCST index indicated no genetic influence on the WCST performance. However, the shared environmental influence was significant and ranged from 30% to 38% on Perseverative Errors, Perseverative Responses, Categories Achieved, and Conceptual Level Responses. Conclusions: The WCST performance among adolescents was influenced by shared environmental factors, rather than genetic factors. The results have important implications for the utility of WCST as a tool for studying executive function.