2018-08-012024-05-15https://scholars.lib.ntu.edu.tw/handle/123456789/666346摘要：人類對於適應新的情境與脈絡展現出卓越的認知彈性，這種彈性需要我們的大腦能有效地調整其功能狀態，並根據任務脈絡產生適當的反應。這種能力更依賴大腦將注意力集中在與任務目標相關的訊息上，將這些與任務相關的資訊暫時地維持在工作記憶中，並根據任務脈絡引導出合適的行為反應。儘管至今對於注意力和工作記憶的研究有著無可爭辯的進展，但是目前仍然不清楚任務脈絡對於工作記憶作業的預期與記憶訊息維持是如何產生調節。在本研究計畫中，我將透過三個系列研究，從不同層次探討作業脈絡是否與如何對工作記憶表徵產生前攝性的影響。在研究一（第一年），我將藉由工作記憶項目間的可變性來操控任務脈絡，我預期項目可變性脈絡能夠驅使大腦對於記憶項目的預期編碼進而影響工作記憶的容量。在研究二（第二年），我將藉由工作記憶項目位置的可變性來操控任務脈絡，我預期位置可變性脈絡能夠觸發大腦對於記憶項目位置的預期編碼而影響訊息進入工作記憶的能力。在研究三（第三年），我將藉由工作記憶延遲時間的可變性來操控任務脈絡，我預期延遲可變性脈絡能夠影響大腦對於延遲時間的預期編碼，使處於隱藏狀態的工作記憶表徵得以重新活化。為了探討這些問題，我將使用行為測量與非侵入性腦功能影像方法，包括功能性磁振造影、腦電圖、腦磁圖、跨顱磁刺激和跨顱電刺激。本計畫所提出的成果將為人類的認知彈性，即任務情境對於個體行為的影響，建立實證基礎並能強力推動更深入的工作。<br> Abstract: Humans exhibit remarkable cognitive flexibility to adapt to novel situations and contexts. Such flexibility also requires the brain to optimally adjust its functional states and lead to appropriate responses depending on the task context. This ability also relies heavily on the brain to direct attention towards the information that is the most relevant to the task goals and to maintain the information in working memory (WM) over a short period of time to guide adaptive behaviours for a given contextual episode. However, despite the undisputed advances of research on attention and WM to date, the field has scarcely considered the natural and critical role that task context plays in driving proactive influences on the preparation and maintenance for the relevant events for delayed responses. This grant proposal aims to explore whether and how task contexts could enable proactive influences on the representations of WM across three studies. In Study I (first year), I will manipulate the task context via item variability across trials. I expect that item-variability context could trigger anticipatory codes for the possible items and influence WM capacity. In Study II (second year), I will manipulate the task context via location variability across trials. I expect that location-variability context could trigger anticipatory codes for the possible locations and enhance the gain of information into WM. In Study III (third year), I will manipulate the task context via delay variability across trials. I expect that delay-variability context could trigger anticipatory codes for the delay intervals and affect the reactivation of the hidden WM state. To address these issues, I will use behavioural measures as well as noninvasive brain imaging methods including functional magnetic resonance imaging (fMRI), electroencephalography (EEG), magnetoencephalography (MEG), transcranial magnetic stimulation (TMS) and transcranial direct/alternative current stimulation (tDCS/tACS). Findings from the proposed experiments will build up the empirical foundation and provide the intellectual impetus for in-depth work into this essential but this far neglected aspect of human cognition – the way in which task contexts can proactively affect our behaviours.認知彈性任務脈絡工作記憶注意功能性磁振造影腦電圖腦磁圖跨顱磁刺激跨顱電刺激Cognitive flexibilitytask contextworking memoryattentionfunctional magnetic resonance imagingelectroencephalographymagnetoencephalographytranscranial magnetic stimulationtranscranial direct/alternative current stimulation