遠距聯想在創造力形成歷程之運作機制

Abstract

遠距聯想為個體生產創造力的重要元素。Mednick依其連結理論發展遠距聯想測驗以評估此能力，然而過往以此為工具的認知神經科學研究偏重於個體解答時所引發的頓悟經驗，卻未能區辨正確答案之產出係來自遠距聯想或近距聯想，致使目前研究成果未能知悉個體透過遠距聯想產生創意之大腦運作機制。據此，本研究編製符合連結理論之遠距以及近距聯想測驗，分別由功能性與結構性腦影像觀點探究遠距聯想及近距聯想之大腦運作機制。實驗一先透過比較參與者在兩種試題各項行為指標之差異以確認自編工具的效度，結果顯示個體解答遠距聯想試題比近距聯想試題需要更長的時間、其答對率亦較低。實驗二採用功能性磁振造影（fMRI）分別比較參與者在兩組試題正確解題與否的大腦活動，以解析個體藉由遠距聯想與近距聯想產出答案的大腦機制，並進一步透過比較上述兩組的差異以剖析遠距聯想的核心成份。結果發現，遠距聯想產出答案與雙側海馬旁回（PHG）、右側頂下葉（IPL）、雙側顳中回（MTG）、左側顳上回（STG）的活化有關；由近距聯想產生答案則在左側額中回（MFG）、右側額上回（SFG）有較高的激發。，負責語義記憶提取與監控工作記憶的左側顳上回（STG）與右側顳中回（MTG）則與遠距聯想核心成份有密切連結。實驗三改由結構性腦影像觀點，以圖形理論分析擴散張量影像，在控制性別、年齡、智力後，結果指出遠距聯想表現與腦網路全局效率有顯著正相關、與標準化的局部效率及小世界屬性為負相關，並在左側偏中顳中回（MTG）與梭狀回（FG）、右側頂下葉（IPL）、腦島（insula）、中間扣帶（median cingulate）、角回（AG）、距狀裂（calcarine fissure）及頂上回（SPG）等區域與其節點連結效率具顯著正相關；近距聯想表現則與全局效率顯著負相關。整體而言，本研究為國內首次同時由功能性與結構性腦影像觀點探討遠距聯想在創造力生成歷程之大腦運作機制，研究結果提供全面性的創造力生理基礎之實徵證據。 The ability of remote association is important to the creativity. By the idea of Associative Theory, Mednick developed the Remote Associates Test (RAT) to measure the creativity. Among previous studies of problem solving process in cognitive neuroscience approach, it generally emphasized the role of insight but ignored the work of remote association which is essential to solve the problem. Therefore, we know less about the neural correlates of remote association and the creativity. To address this issue, present study develops the remote association and near association tests according to Associative Theory, and investigates the neural correlates of remote and near associations from the perspectives of functional and structural MRI. In study 1, the behavioral indices of subjects in near and remote association tests were compared, result showed that problem solving time was longer, the correct percentage was lower, the correlation with fluency test was higher, and the times of A-HA was fewer in the remote association test than in near one. In study 2, it used the technique of fMRI to record the change of Blood Oxygenation Level-Dependent (BOLD) in two seconds before the problem solved for finding the mechanism of near and remote association and analysis the key of remote association. The result shows that remote association was correlated to the activation of the PHG (Parahippocampal Gyrus), the IPL (inferior parietal lobe), the MTG (middle temporal gyrus), and the STG (superior temporal gyrus); while near association was correlated to the arousal of the MFG (middle frontal gyrus) and the SFG (superior frontal gyrus). Besides, the STG and MTG where are responsible of semantics retrieval and working memory monitoring were found to be highly relevant to the key of remote association. The study 3 was a structural neural image study and analyze the DTI (Diffusion Tensor Imaging) pictures according to the Graph Theoretical Analysis. After controlling the gender, age and intelligence factors of subjects, it shows that remote associationwas positively correlated to the global efficiency of brain networking but negatively correlated to the standardized local efficiency and the small-worldness. It also shows that remote association was positively correlated to the activation of MTG,FG (fusiform gyrus), IPL, the insula, median cingulate, AG (angular gyrus), calcarine fissure, and SPG (superior parietal gyrus) as well as to the node efficiency of these brain areas. As for the near association, it found to be negatively relevant to the global efficiency. Present study is the pioneer which investigates the neural correlates of remote association in the process of creativity by the perspectives of functional and structural MRI. The study results contribute the overall empirical data for the physiological basis of creativity.