- 學位論文
以ERPs及TMS檢視攻擊行為的神經機制
Using ERPs and TMS to investigate the neural correlates of aggressive behavior
摘要
近年發生了多起的青少年暴力犯罪事件，暴力行為已經造成社會相當嚴重的影響。暴力行為的成因相當複雜，包含社會、心理與生物因素皆參與在其中，本研究主要探究暴力行為背後的神經生理成因，本研究透過泰勒攻擊典範(Taylor aggression paradigm, TAP)來誘發受試者產生攻擊情境及情緒反應，藉此來模擬攻擊情境，使用腦波儀(Electroencephalography,EEG)及跨顱磁刺激儀（Transcranial Magnetic Stimulation,TMS）分別來探討暴力行為相關的神經機制。實驗一使用腦波儀紀錄暴力青少年、非暴力犯罪青少年與一般青少年在抑制能力與負面情緒調節能力上的差異，行為結果發現暴力犯罪青少年在泰勒攻擊典範給分顯著高於其他兩組，另外在腦波結果上顯示的在決定階段的N2 振幅顯著性較低，推斷其抑制能力可能較弱;結果階段的FRN波振幅顯著性較低，在情感同理方面能力較弱，且在本實驗運用反應性-主動性攻擊行為問卷與負面情緒調節量表可知，反應性與主動性攻擊行為兩者具有高相關性，且攻擊行為程度與負面情緒調節能力為負向關係。推論暴力青少年在接受到挑釁情境中，具有較弱的抑制控制能力，且對於所引發負向情緒(如:生氣)調節能力較差，所以會在實驗過程中普遍給予對手高程度懲罰。 透過實驗一結果，欲進一步探討反應性與主動性暴力行為相關的神經機制，實驗二採用持續性θ突波磁刺激(Continuous Theta Burst Transcranial Magnetic Stimulation，cTBS -TMS)施打於右側背內側前額葉皮質(Dorsomedial Prefrontal Cortex，DMPFC)，此區域主要與認知抑制控制有關，尤其是在社會互動的情況下，涉及「報復」動機執行。實驗二對象包含兩組皆為一般大學生，其一實驗組施打cTBS –TMS於右側背內側前額葉皮質區域，而控制組則施打cTBS –TMS於Vortex區域，兩組皆進行泰勒攻擊典範來比較兩組給與對手懲罰分數之行為差異，實驗二結果顯示兩組人反應性-主動性攻擊行為問卷與負面情緒調節量表得分上無差異，但是在泰勒攻擊典範中未受挑釁情境下給與對手的懲罰分數有所差異，實驗組顯著高於控制組，也就是說實驗參與者施打cTBS –TMS於右側背內側前額葉皮質區域會增加主動性攻擊行為傾向；另外在泰勒攻擊典範中受挑釁情境下給與對手的懲罰分數沒有差異，在此實驗中未發現反應性攻擊行為兩組人有所區別。推論本實驗採用非侵入式cTBS –TMS施打於右側背內側前額葉皮質區域降低該區域活性，右邊前額葉區域主要扮演避免動機執行，藉此調控增加主動性攻擊行為傾向。 總結以上，暴力青少年在接受到挑釁情境中，有較差的抑制控制能力，且對於負向情緒調節能力較差，而在主動性攻擊行為與反應性暴力行為神經機制在動機執行能力上可能有不同調控機制。
並列摘要
Aggressive behavior often causes very serious problems and dangers to society. In addition to being a general problem, a number of violent crimes involving juvenile offenders have occurred in recent years. The reasons for such aggression are quite complex, and can include social, psychological and biological factors. The current study focuses on exploring the neurophysiologic causes of aggression, and in particular in juvenile offenders, through use of the Taylor aggression paradigm (TAP) that is designed to induce aggression and negative emotion in participants. The first study combined this task with EEG in offenders and the second used Transcranial Magnetic Stimulation (TMS) in normal participants to investigate the neural mechanisms related to aggression. In experiment 1 the TAP combined with EEG was used to compare violent juvenile offenders, non-violent juvenile offenders and general teenagers. The behavioral results showed that violent juvenile offenders gave higher punishment scores to opponents. The amplitude of N2 ERP component in the decision stage and the amplitude of the FRN component were significantly lower for this group. This data is consistent with violent juvenile offenders having poor ability in both inhibitory and emotional aspects. Reactive Proactive Aggression questionnaire scores and Negative Mood Regulation (NMR) scale results showed that reactive and proactive aggression were highly correlated and the aggression tendency and the regulation of negative emotions have a negative relationship. These results indicate that violent juvenile delinquents in provocative situations have poor inhibitory control and negative emotional regulation from the findings from N2, FRN and the questionnaire. In experiment 2, Continuous Theta Burst Transcranial Magnetic Stimulation (cTBS –TMS) was used to reduce activity in the right side of the dorsal medial prefrontal cortex (DMPFC), an area mainly concerned with cognitive inhibitory control, especially in the implementation of social interactions involved in motivation. Volunteer male university students were divided into two groups, an experimental group receiving cTBS -TMS is over the right dorsomedial prefrontal cortex and a control group with stimulation over the vertex. Performance of the two on the Taylor aggression paradigm was compared. While the scores on the Reactive Proactive Aggression questionnaire and Negative Mood Regulation scale were not different for the two groups, cTBS -TMS applied to the right dorsomedial prefrontal cortex increased proactive aggression. These results suggest proactive aggression may be more closely related to the neural mechanisms of motivation. In summary, in violent adolescents presented with provocative situations, these individuals show poor inhibitory control, and poor regulation of negative emotion. Proactive and reactive aggression seem to have different neural mechanisms that may relate to motivation.