學習後之介入活動對記憶形成之影響：時間相依效果

Abstract

記憶固化假說認為，新習得的記憶痕跡隨時間而逐漸穩定，因此在學習活動過後不久，記憶處於較不穩定的狀態，也較易被學習後事件干擾。證據顯示學習後的休息有利於記憶的提取，但記憶是否隨著時間逐漸不受干擾，在人類的研究中尚不清楚。本研究使用圖像與文字列聯列表作為學習刺激，在目標學習之後加入介入學習，並操弄兩學習活動之間的時間間隔（立即或延遲），以測試立即學習後介入記憶穩固的時間特性。本研究中包含四個實驗，包含下列所述的程序: 在延遲干擾組，受試者第一天將在學習目標列表後，間隔一段時間學習介入列表；立即干擾組在學習目標列表後緊接著學習介入列表，之後間隔一段時間。兩組受試者在第二天進行兩列表的再認測試，受試者對於目標列表的記憶表現會使用信號偵測理論的敏感度指標表示。在本研究中發現了兩個主要的混淆變項: 1. 因為多次測試而產生的測試增益效果；2. 在兩列表間或後的間隔時間所進行的注意力作業產生了不必要的心智損耗。在實驗四中排除了這兩混淆變項後，立即干擾組的表現在第二天的記憶表現有明顯的下降，而延遲干擾組則否。我們發現學習後介入的干擾效果會隨時間而遞減，這樣的發現符合記憶穩固理論。

Memory consolidation is a process during which a memory trace becomes stable and resistant to disruption over time. This process is supported by evidence that a period of rest after learning would enhance retention of learned materials. However, whether a memory trace in humans would become more resistant to post-learning interference along with time has been questioned. This study aimed to examine the time-dependent influence of the post-learning intervention on consolidation of associative memory for figure-word pairs. Four experiments were conducted in this study, in which two groups of participants were randomly assigned into an immediate intervention (II) condition or a delayed intervention condition (DI) on day 1. In the II condition learned the target list, followed immediately by learning the intervention list, and finally receiving the delay interval. In contrast, participants in the DI condition, participants learned the target list, followed by a delay interval, and then learning an intervention list. Memory performance was assessed by recognizing target pairs from foil pairs and indexed by sensitivity (d-prime) of signal detection analysis. We found that the reduction of the d-prime score for detecting the target pairs from day 1 to day 2 was greater in the II condition than in the DI condition in Experiment 4. Our findings indicate that learning an intervention list immediately after the target list produced more interruption on the 1-day memory than listening to music, suggesting that consolidation of memory is impaired by processing similar materials in a time dependent manner.