記憶負荷量以及運作同質性對雙作業協調的影響

Abstract

本研究利用雙重語音及空間n-back作業，操弄兩作業間的記憶負荷量，以探討工作記憶（working memory）架構中的中央執行（central executive）在協調視覺空間模板（visuospatial sketchpad）和語音迴路（phonological loop）兩個奴隸系統（slave system）的作業時，如何受到記憶負荷量與作業運作同質性（operation sameness）的影響。實驗一藉由操弄兩種作業的記憶負荷量之間的配對，形成同質與異質的雙作業運作情境。實驗二檢驗實驗一的結果是否來自於限定受試者反應順序所造成，實驗三排除了受試者以語音登錄空間作業的策略，而在實驗四裡，我們固定相同的記憶負荷總量，觀察同質性和異質性運作的差異如何影響中央執行的協調效能。結果顯示同質性的雙作業運作有利於提升中央執行協調的效能。

We investigated how the central executive (CE) coordinates dual N-back tasks between two slave systems with the manipulation of memory load. The verbal load and the spatial load were orthogonally manipulated, with operation congruency defined by whether the number of backtracking steps for comparison was identical or not between the two tasks. The results of Experiment 1 shows that memory load and operational sameness will affect the efficiency of coordination. The results of Experiment 2, in which the participants always reported the verbal response before reporting the spatial response, showed the congruency effect only in verbal performance. The verbal load effect decreased when the spatial load was two. The response order was manipulated in Experiment 2 to examine whether the congruency effect could be obtained and Experiment 3 was designed to reduce verbal coding of spatial locations. The results showed the congruency effect in both experiments. We fixed the total memory load (n) of verbal and spatial task at 4 then we manipulated the operation congruency in Experiment 4. The results of inter response interval showed that participants with high performance were different from participants with low performance. This study could reflect the capacity constraint of CE and the efficiency of the executive control of visual attention when people coordinate two concurrent tasks.