臺灣博碩士論文加值系統

摘要
跳視的準確與否，和傳送到運動神經元之刺激訊號強度有關。如果在跳視的神經傳導路徑中，有某些神經元產生病變或退化，跳視將會失去其準確度。近來已有許多神經生理及神經解剖的研究資料陸續被提出，除了可以解釋跳視產生的神經生理機制外，也有助於跳視系統的模擬。
對於利用目前已發展的跳視模型來模擬人類跳視的過程中，一般會遭遇兩個問題。第一，幾乎所有的模型都是根據所量測知猴子數據所建立的，而猴子的跳視要比人類快許多。而調整模型某些參數可以有效地降低速度，產生較慢的跳視。第二，目前跳視模型的效率皆經由評估主序列之動態關係為基礎，並未考慮到其它參數（例如，加速時間和曲斜率）。腦幹模型乃是基於猴子外展神經核的生理資料所建構的模型，目前雖然已被應用在模擬人類警覺程度及猴子小腦病變的跳視軌跡上，但其所產生的速度軌跡之加速時間太短。而利用最小變異理論所發展出的模型加速時間則太長。
在本論文中，我們嘗試利用靈長類的小腦模型模擬人類的跳視軌跡。經由調整腦幹之相關參數及齒狀核動眼區（FOR）之輸出訊號，小腦模型可以有效產生加速時間和實驗數據非常一致之跳視軌跡。本研究發現整合齒狀核動眼區和腦幹之小腦模型可以有效地產生與現有的跳視軌跡非常一致的跳視軌跡。另外我們證明小腦在跳視加速相與減速相的時間調控扮演非常重要的角色。

Abstract

To attain saccadic accuracy, it requires that the control signals sent to the motor neurons have to be the right size to bring the fovea to the target. Accuracy will be lost if the neurons responsible for the generation of saccades are degenerated or disordered. Recently, neurophysiological and neuroanatomical data have been proposed to explain the mechanism of saccade generation, which are also helpful in modeling saccadic system.
There are two problems encountered for the existing models in generating accurate human saccades. Firstly, most models were built based on the data recorded from monkeys that were known to generate faster saccades than the human, several parameters have to be adjusted to fit slower saccades for the latter. Secondly, efficiency of the existing models was judged by the main sequence relations only, while other parameters such as acceleration time and skewness are not considered at all. For example, the brain stem model, which was constructed based on the primate abducean neurons and has been used extensively in simulating saccades with bluntness of vigilance state and lesioned cerebellum, generates velocity profiles with the acceleration time is too short, while it is too long for the model developed based on the minimum variance theory.
In this thesis, we intended to simulate human saccades by tuning the parameters based on the cerebellar model that were built according to the primate data. By tuning the parameters of the brain stem and the signals from the fastigial ocular region (FOR), the cerebellar model is able to generate velocity profile that the acceleration time is in agreement with the experiment. It is concluded that the cerebellar model, which integrates the FORs and the brain stem, can efficiently generate velocity profiles agreed with the recorded profiles. Also the cerebellum plays an important role in chronically regulating the time course of acceleration and deceleration phases of saccades.

目錄
中文摘要………………………………………………….. I
英文摘要…………………………………………………. II
誌謝…………………………………………….……… III
目錄………………………………………………… IV
表目錄…………………………………………………….VI
圖目錄………………………………………………VII
第一章 緒論………………………………………….. 1
第1-1節 眼球運動介……………………………………1
第1-2節 眼球運動之分類………………………………2
第1-3節 跳視眼球運動的分類…………………………5
第1-4節 跳視眼球運動的腦幹神經生理機制…………5
第1-5節 眼球運動的量測技術…………………………8
第1-6節 研究動機與目的…………………….……….10
第二章 跳視眼球運動…………………………………11
第2-1節 跳視眼球運動的量化參數……………………11
第2-2節 跳視系統的神經生理學與神經解剖…………15
第2-2-1節 眼球系統的動態特性……………………….15
第2-2-2節 脈衝產生器的模型…………………….…..16
第2-2-2-1節 開迴路模型……………………….…….17
第2-2-2-2節 閉迴路模型……………………….……19
第2-2-3節 上丘的模型……………………….………..28
第2-2-4節 跳視眼球運動之大腦皮質的牽涉………….31
第2-3節 不正常的跳視…………………………………33
第2-3-1節 不正常的跳視速度………………….…..34
第2-3-2節 不正常的跳視初始現象…………………34
第2-3-3節 不正常的跳視準確性…………….……..34
第2-4節 實驗的刺激樣式………………………………35
第三章 材料與方法………………………………….37
第3-1節 跳視神經傳導模型……………………………37
第3-1-1節 腦幹跳視模型……..……………...……37
第3-1-2節 小腦-腦幹跳視模型…………………….…41
第3-1-3節 上丘-腦幹跳視模型………………………...44
第3-2節 模型參數與跳視軌跡之關係…………….….48
第3-2-1節 腦幹跳視模型………………………..…..48
第3-2-2節 小腦-腦幹跳視模型……………….…...…52
第3-2-3節 上丘-跳視模型………………………………54
第3-3節 猴子與人類跳視軌跡之比較…………….….55
第3-4節 依據猴子跳視模型，模擬人類跳視軌跡……56
第3-4-1節 腦幹模型參數的轉換…..……….….......56
第3-4-2節 小腦-腦幹模型參數的轉換………………..58
第3-5節 跳視模型之使用者介面…………….….….61
第四章 結果與討論………………………………….64
第4-1節 整各系統模型的架構…………………………64
第4-2節 猴子之跳視軌跡的比較………………………66
第4-2-1節 模型之跳視參數…………………………..66
第4-2-2節 模型參數的比較……………………………..66
第4-3節 人類之跳視軌跡………………………………67
第4-3-1節 根據腦幹模型模擬人類跳視軌跡………….68
第4-3-2節 根據小腦-腦幹模型模擬人類跳視軌跡……72
第4-4節 各跳視模型的限制……………………………76
第4-5節 各跳視模型之加速時間的比較…………….77
第4-6節 小腦-腦幹跳視模型之擴充……...……….79
第4-7節 討論與結論…………………………….….81
第4-8節 未來工作…………………………….…….83
參考文獻………………………………………………….86


表目錄
表1-1各種眼球運動紀錄的比較……………………..….9
表3-1腦幹跳視模型之標準參數值…….……………39
表3-2 小腦之FOR權重………………………………43
表3-3上丘之參數標準值…………….………………..…47
表4-1各模型所模擬之跳視軌跡參數值……….……..…66
表4-2各個模型之10度跳視參數的比較………………67
表4-3實驗的跳視速度軌跡資料……………………..…68
表4-4根據文獻資料調整腦幹模型參數所模擬之跳視軌跡資料...........................................69
表4-5根據本實驗室資料調整腦幹模型參數所模擬之跳視軌跡資料…………………………………………….71
表4-6模擬文獻資料之小腦FOR權重值………………72
表4-7根據文獻資料調整小腦-腦幹模型參數所模擬之跳視軌跡資料……………………………………….73
表4-8 模擬我們實驗室資料之小腦FOR權重………74
表4-9根據本實驗室資料調整小腦-腦幹模型參數所模擬之跳視軌跡資料…………………………………….….74
表4-10不同跳視角度之小腦FOR權重值….……..…..79



圖目錄
圖1-1 眼球肌肉位置圖………………………….….…2
圖1-2 A.轉向系統；B.轉斜系統；C.轉向、轉斜組合.3
圖1-3 眼球運動之分類…………….….…………………3
圖1-4 跳視的腦幹神經傳導機制………………….….…7
圖2-1 跳視潛伏期(L)的量測…….……………….…..12
圖2-2 跳視區間(D)與峰值速度(Vm)的量測.…….….13
圖2-3 外展(a)和內旋(c)跳視之動作區間與振幅的主序列關係。外展(b)和內旋(d)跳視之峰值速度與振幅的主序列關係..…..…..................................14
圖2-4 眼球移動到一個新位置需要停留約200 ms 且與刺激的時間長短無關，實線表示刺激目標的軌跡，虛線表示眼球移動軌跡………………………………………..17
圖2-5 取樣-資料模型……….………….…………….18
圖2-6 (a)“Step-by-Step”與“Skip-over”的圖解。 (b) “Step-by-Step” 會隨著 ISI的變大而增加, 但對於“Skip-over”的情形，反而會隨著ISI變大而減少。(c)模型之結構圖..…..…....………..............18
圖2-7 跳視之脈衝-步階模型..…………………..……20
圖2-8 Robinson模型證實動眼神經系統為一個閉迴路的系統..…........................................21
圖2-9 以外展神經核的爆發神經活動為基準所建構的跳視模型..........................................22
圖2-10 小腦的FOR被整合到圖3-11腦幹模型中的跳視模型……..........................................23
圖2-11 包含一個會漏電的積分器之轉位跳視模型..…24
圖2-12 正常人以及靜脈注射鎮定劑之受測者的振幅與動作區間關係……………………………………………….25
圖2-13 Tweed 和 Vilis (1985)所提出的二維跳視模型…….....................................……26
圖2-14 Scudder (1988) 將抑制迴受神經(IFN)整合到迴受路徑中27圖2-15 上丘的(a)地形圖像。(b)視覺場…29
圖2-16 利用類神經網路模擬上丘的兩層細胞活動情形之跳視模型………………………………………………….30
圖2-17 牽涉大腦皮質之跳視眼球運動模型..…………33
圖3-1 利用Simulink所設計之腦幹跳視神經模型……38
圖3-2 爆發神經與運動誤差的關係圖..…………….…38
圖3-3 模擬跳視眼球運動之位置與時間關係圖………40
圖3-4 模擬左右邊爆發神經之發射狀態………………40
圖3-5 利用Simulink所設計之小腦-腦幹跳視神經模型41
圖3-6 兩側FOR之脈衝發射時間關係圖…………..……42
圖3-7 實際資料（A）與模擬（B）之FOR發射狀態的比較…...........................................43
圖3-8 10度正常與小腦病變的跳視速度軌跡比較……44
圖3-9 利用Simulink所設計的上丘－腦幹模型之上丘部分…...........................................45
圖3-10 利用Simulink 所設計之上丘-腦幹神經傳導模型….........................................…46
圖3-11 上丘模型與Simulink模型之跳視振幅軌跡（0度~15度）........................................47
圖3-12 不同bm值之(a)位置與(b)速度軌跡圖……...49
圖3-13 不同bk值之(a)位置與(b)速度軌跡圖…………49
圖3-14 不同OPN bias值之(a)位置與(b)速度軌跡圖…50
圖3-15 當bm值固定後，改變OPN bias值之(a)位置與(b)速度軌跡圖…………………………………………………51
圖3-16 不同T1值之(a)位置與(b)速度軌跡圖……..….51
圖3-17 不同T2值之(a)位置與(b)速度軌跡圖……..….52
圖3-18 不同cFOR權重值之(a)眼球位置與(b)速度軌跡53
圖3-19 不同iFOR權重之(a)眼球位置與(b)速度軌跡關係圖…...........................................54
圖3-20 猴子與人類跳視之主序列關係及加速時間比較.55
圖3-21 調整bm（1100~500 deg/sec）之位置與速度軌跡分布….........................................57
圖3-22 調整OPN bias之位置與速度軌跡分布…………57
圖3-23 調整T1及T2之位置與速度軌跡圖……………..58
圖3-24 調整cFOR權重（0.1~0.36）之位置與速度軌跡分布…...........................................59
圖3-25 調整iFOR權重（0.185~0.24）之位置與速度軌跡分布...........................................59
圖3-26 調整cFOR之發射狀態…………………………….60
圖3-27 cFOR發射狀態調整前後之(A)位置與(B)速度軌跡…….........................................60
圖3-28 跳視眼球運動模擬系統之程式主畫面……….…61
圖3-29 模型之相關參數值輸入介面……………..…..61
圖3-30 位置軌跡比較之操作介面………………..……62
圖3-31 跳視位置軌跡參數值之比較介面………….…..62
圖3-32 跳視速度軌跡比較之操作介面…………………63
圖3-33 跳視速度軌跡參數值之比較介面………………63
圖4-1 整個系統的模型架構…………………………….65
圖4-2 三個模型之主序列動態特性比較………………67
圖4-3 文獻數據與本實驗室數據之主序列關係及加速時間比較..........................................68
圖4-4 文獻實驗數據與模擬結果之主序列關係及加速時間比較..........................................70
圖4-5 本實驗室實驗數據與模擬結果之主序列關係及加速時間比較.……………………………………………..71
圖4-6 為模擬人類對側與同側FOR在10o、20o、30o之發射狀態..........................................72
圖4-7 小腦-腦幹模型之模擬結果與文獻資料之主序列關係及加速時間比較…………..……..............……73
圖4-8 實驗數據與模擬結果之主序列關係及加速時間比較…...…......................................75
圖4-9 各模型之10o、20o、及30o速度軌跡比較圖……78
圖4-10 各模型所產生之軌跡的跳視加速時間比較…..78
圖4-11 模擬5o~40o之人類小腦FOR發射狀態……………79
圖4-12 (A)依文獻和(B)本實驗室之實驗數據所模擬之速度軌跡..........................................80
圖4-13 文獻之實驗數據與模擬結果之主序列關係的比較….…........................................80
圖4-14 cFOR與iFOR之合成輸出訊號……………….….82
圖4-15 跳視模型系統之示意圖…………..…….....…84
圖4-16 巴金森氏症患者和正常人之主序列關係及加速時間比較…..……………………………………………84
圖4-17 模擬正常人與巴金森氏症患者的cFOR發射狀態............................................85
圖4-18 巴金森氏症患者與模擬結果之主序列關係及加速時間比較….………………………………………………85

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