Common and differential brain regions associated with retrieving spatial and non-spatial information from episodic and semantic memory

論文發表人：林君昱 (亞歷桑納大學心理系認知神經科學研究所博士班)

 

http://www.cnsmeeting.org/

 

本研究利用功能性核磁共振大腦影像掃描（fMRI）檢驗與情節及語意記憶中空間及非空間訊息提取歷程有關之大腦區域。在學習階段，受試者觀看六組在螢幕上呈現之圖片。每組圖片包含四個位於螢幕四個角落之不同物品。受試者必須記起各物品圖片的細節及其位置。在測驗階段，受試者須回答一系列之相關比較性問題。每個問題中，有二個物品的名稱以文字型式呈現以作為比較。測驗問題共包含五大類：情節記憶-空間訊息、情節記憶-非空間訊息、語意記憶-空間訊息、語意記憶-非空間訊息，以及控制組。在語意記憶問題中之物品有可能是已學習過的或是新呈現的。研究結果發現，當人類回憶提取不同類之訊息時，許多相似的大腦區域都有參與，但同時也各自利用了一些獨特的大腦區域來完成任務。例如，顳葉內側後緣與情節記憶及空間訊息提取較為相關，但顳葉內側前緣則與語意記憶及非空間訊息提取較相關。內側頂葉（Precuneus）與「熟悉感」較相關，但及外側頂葉則與空間訊息處理較相關。本研究亦討論了這些結果及各變項間之交互作用。本研究之結果提供了人類記憶神經機制更深一層的認識。

The present study examined the brain regions involved in the retrieval of spatial and non-spatial information from episodic or semantic memory using event-related fMRI. In the study phase, participants viewed six object arrays (each had pictures of objects in four quadrants), and were instructed to remember the objects, their locations, and the details of their appearance. At test, participants were presented with verbal names of two objects at a time during scanning and made relational judgments on questions from the following conditions: EPISODIC SPATIAL, EPISODIC NON-SPATIAL, SEMANTIC SPATIAL, SEMANTIC NON-SPATIAL, and CONTROL. Objects in the semantic conditions were either from the study phase or new. Results indicated similar brain activation patterns across all the memory conditions. However, the various conditions yielded differential activations in terms of magnitude, cluster size, and location in specific sub-regions. For example, posterior medial temporal lobe (MTL) was more active for episodic and spatial conditions than semantic and non-spatial conditions, while anterior MTL showed the opposite pattern. Precuneus and lateral parietal regions also showed differential activations that might be related to "perceived familiarity" and spatial processing, respectively. For instance, even when using the same semantic questions that did not require episodic retrieval (e.g. which object is normally softer), precuneus was more active when the objects in the questions had been studied in the study phase than when they were new, perhaps reflecting involuntary feelings of familiarity. Interactions between conditions and the implications of the results will be discussed.