- 學位論文
探討小腦與大腦之功能性聯結與其於音樂情緒刺激及記憶活動中的功能定位
Functional Interaction between Cerebellum and Cerebrum: Its Role in Memory and Musical Emotion
摘要
大腦神經與認知科學在近數十年來一直是一個熱門的研究議題，許多研究者們嘗試許多的方法只為了要解開未知的大腦謎團．然而，在大多數的研究者把全數精力放在解開大腦的奧秘時，他們往往有意無意地忽略了小腦在諸多認知活動中的活化．在過去多數的文獻中，小腦一直只被認定為擁有體感、動作、與平衡相關的功能．然而，在最近一二十年的文獻中，已經有越來越多的文獻關注到小腦也在許多的大腦認知實驗中有所活化，這也引發了我們的興趣來探討究竟小腦與哪些認知歷程有所關聯． 為了探究小腦的功能與定位，在第ㄧ個實驗中，我們採用了靜息態功能性磁振成像技術，結合以奇異數輔佐關聯性分析，運用於五十六位正常受試者，以獲取其小腦功能性分區．在實驗結果中，透過小腦與大腦所展現出來之功能性連繫可知，小腦不但與大腦負責體感與動作相關之區域有所連結，更在其他的功能性分區裡顯示出其與大腦之情緒、記憶、語言、空間定位、與預設模式網絡有所連繫．其結果中的小腦情緒網路顯示出小腦後葉與大腦邊緣系統有強烈的功能性連結． 為了驗證小腦在情緒活動中的參與，在第二個實驗中，我們操作音樂所引發的情緒，來探討小腦是否會對其有所活化反應．結果顯示，小腦的前後數個小葉的確在副歌抽離的失落情感與享受副歌之滿足情感下有所反應．這個實驗不但證明小腦於情緒處理歷程中佔有一席之地，其活化區域亦與第一個實驗中所得到的小腦情緒網路區域一致． 除了情緒網路之外，在第一個實驗所得到的小腦功能性分區中，小腦的絕大多數小葉幾乎都與大腦之記憶相關區域有所聯繫．進一步，為了佐證這個結果，我們設計了第三個實驗：記憶回朔與記憶固化．運用區域成對相關係數分析之下，於記憶回朔實驗結果中，我們看到小腦後葉有極大的反應．而在記憶固化實驗結果，小腦第七小葉在記憶固化歷程中的確顯示出與其他腦區域之功能性連結有所顯著提升．這結果的確是與第一個實驗所得到的小腦記憶網絡一致，也顯示出這個小腦在記憶活動中確實是一個重要的部分． 我們在這三個實驗中探究了小腦與大腦的功能性活化．小腦的諸多諸區域不但如先前的研究中所提到負責低階之體感、動作、與平衡，同時，其亦參與了許多高階認知、記憶、與情感的心智活化．藉由這三個實驗之發想與初步貢獻，小腦，展現出更多與更完整之面貌．
並列摘要
Previous researchers mostly focused on cerebrum and tried to investigate the mysterious function of our brain. In decades, some researches tried to investigate the mystery of the cerebellar cognitive functions and the connection between cerebrum and cerebellum. Previous animal research demonstrated somatotopic representations of motor responses in the cerebellum. However, more and more researches had pointed out that the cerebellum also activates in high cognitive mental activity as one cooperator of the cerebrum, and it also aroused our interesting about that how many cognitive processes are cerebellum participates in? To investigate the cognitive functions of cerebellum, we used one novel analysis to separate the functional connectivity between cerebellum and cerebrum in the first study of this dissertation. Applied the novel analysis to the resting-state functional data from 56 participants, we acquired 15 cerebellar functional connectivity patterns, including of motor, somatosensory, language, visuospatial, emotion, default-mode network (DMN), and memory. In the result, the cerebellar emotion pattern showed interested functional connection between posterior cerebellum and the cerebral limbic regions; moreover, those cerebellar functional patterns showed one interesting result that most of the posterior cerebellar regions showed functional connectivity with the cerebral memory networks. In the second study of this dissertation, we tried to investigate the mental activity of cerebellum during music-induced emotion. In the result, anterior/posterior cerebellar lobules indeed showed strong activation during three emotional conditions, including of reward-gain and reward-loss situations. This study confirmed that previous fMRI researches that showed cerebellum took part in the emotional processes, and the activation during musical emotion was agreed with the cerebellar emotion pattern showed in the study 1. In the third study, task-based fMRI of memory consolidation and memory retrieval was used to confirm the cerebellar memory patterns. Based on the regional pairwise correlation coefficient (RPCC) analysis, cerebellar lobule VII showed significant variation during memory consolidating. Similar to the result of memory consolidation, posterior cerebellar regions activated during memory retrieval. This result was agreed with the cerebellar memory patterns in the first study. In this dissertation, our results showed that cerebellum not only activated in the mental activity of motor-related function and somatosensory but also participated in the cognitive processes including of the music-induced emotion and verbal memory. In conclusion, cerebellum, as one cooperator of cerebrum, also played important role in high cognitive mental activity as one cooperator of the cerebrum. The cerebellar functional patterns would benefit to the furthering cerebellar researches about cognitive processes. Keyword: cerebellum, fMRI, rs-fMRI, emotion, memory retrieval, and memory consolidation.