慢性精神分裂症患者之逐項記憶與要旨記憶的功能研究

Abstract

正常記憶運作仰賴適當的逐項記憶和要旨記憶。文獻指出精神分裂症患者記憶功能之缺損，與其額葉、顳葉之病理有關。此外，該記憶之受損可能與逐項記憶或要旨記憶有關，並且監控功能之受損亦可能造成過多無關假警報反應，因而影響記憶表現。然而過去研究未能同時考量逐項記憶、要旨記憶、與無關假警報反應對患者記憶的影響。DRM（Deese-Roediger-McDermott）派典可區分逐項記憶、相關項目之錯誤記憶與無關假警報反應等再認指標，並可藉以了解記憶建構的歷程。本研究目的有四，（1）探討慢性精神分裂症患者之神經認知功能；（2）藉DRM派典記憶作業瞭解患者在內涵於記憶中的逐項記憶、要旨記憶、無關假警報反應是否異常；（3）論述患者的逐項記憶、要旨記憶、及無關假警報反應的可能神經心理機制；（4）評估DRM派典記憶作業是否適合做為臨床評估要旨記憶之衡鑑工具。共40位慢性精神分裂症患者，與30位正常受試者參與本研究。在性別、年齡及教育程度無顯著差異。每位受試者接受神經心理功能檢查和DRM派典記憶作業。結果發現：患者在智力、注意力、記憶力、語言與語意記憶、以及執行功能等測驗表現均顯著較正常受試者為差。在DRM派典記憶作業中，精神分裂症患者在相關項目之錯誤再認率表現明顯低於正常受試者；然而在逐項再認與無關假警報反應的作業表現與正常受試者無明顯差異。正常組與患者的相關項目之錯誤再認率指標皆與辭彙能力有顯著相關，患者在工作記憶與圖繪測驗的缺損亦與其受損的要旨記憶有正相關。此外，患者在測量要旨記憶的邏輯記憶分測驗的主題分數與DRM派典記憶作業的要旨記憶表現皆明顯受損。基於上述研究結果，患者要旨記憶的缺損，可能與患者在額葉－顳葉之迴路受損有關。本研究結果顯示DRM派典記憶作業可用以評估要旨記憶，然而臨床應用上有其限制。

Normal memory depends upon both adequate verbatim and gist memory functioning. The issue regarding whether defective memory function in schizophrenic patients results from either impaired verbatim, gist memory functioning, or poor false alarm monitoring has been distinctly investigated. However, little has approached the effects of verbatim memory, gist memory, or false alarm concurrently on these patients’ poor memory functioning. Using the Deese-Roediger-McDermott (DRM) paradigm task, the present study was to make an attempt to explore their constructive processes of memory. Four specific objectives of this study were as follows: to (1) explore neurocognitive functions in patients with chronic schizophrenia, (2) approach the patient’s verbatim memory, gist memory, and unrelated false alarm through the DRM paradigm task, (3) investigate the possible underlying neuropsychological mechanisms regarding the verbatim memory, gist memory, and unrelated false alarm, and (4) examine the appropriateness of the DRM paradigm task to be a clinical tool in assessing gist memory. Forty patients with chronic schizophrenia and 30 healthy normal controls, matched for the sex, age, and education level, participated in the study. All subjects were given a battery of neuropsychological tests and the DRM paradigm task. The results revealed that patients evidenced significant deficits of intellection, attention, episodic memory, language and semantic memory, and executive function. On the DRM paradigm task, the mean gist memory score of the patients was significantly lower than that of normal controls while mean verbatim memory and unrelated false alarm scores of the patients were compatible with those of normal controls. For normal controls and patients, their gist memory scores were significantly positively correlated with the Vocabulary subtest scores. However, only the patients’ gist memory scores were also associated with their working memory index and Visual Reproduction subtest scores. Moreover, the patients had significantly lower gist memory scores of the DRM paradigm task and thematic scores of the Logical Memory subtest compared with their normal counterparts. Based on the results, it thus appears that the patients’ defective gist memory might be related to dysfunction of the frontal-temporal loop, and is further suggested that the DRM paradigm task might be an alternative clinical measure to assess gist memory if its limitations are taken into account.