大腦結構、執行控制功能與暴力犯罪行為關聯性之研究

The Correlation between Brain Structure, Cerebral Executive Control Function and Violent Behavior

鄭添成(Tien-Cheng Cheng)

指導教授 ： 林瑞欽

國立中正大學/教育學院/犯罪防治學系/博士(2008年)

摘要

暴力犯罪對社會所造成的危害是影響深遠的，不僅帶來龐大的社會成本，許多駭人聽聞的案件也加深了民眾的被害恐懼感。暴力犯罪的成因解釋牽涉面廣泛，來自於生物、心理、社會的不同切入點莫不希望能對暴力犯罪有更進一步的認識。本研究從社會認知神經科學的角度，結合大腦磁振造影技術及行為特質測量，來瞭解暴力犯罪行為，藉由採取「生物-社會」多元指標的測量方式來探討研究議題，而此也是台灣在犯罪心理學上的首次嘗試。
本研究受試者計29名，均為男性，依據犯罪前科及犯罪情節區分為情感性暴力犯組、掠奪性暴力犯組、一般犯罪人組、及非犯罪人組進行比較。在行為特質測量上，採用Barratt衝動量表測量受試之衝動性特質；其次採用Buss-Durkee敵意攻擊量表測量受試之敵意攻擊特質；並採用「健康、性格、習慣量表」測量受試之心理健康及性格違常偏差情形。在大腦磁振造影上，則利用結構性磁振造影測量受試之灰質、白質、及腦脊液的容積，並進行外觀觀察比較；其次利用功能性磁振造影測量受試之大腦執行控制功能，分別在工作記憶及注意力實驗作業下，進行功能性腦結構定位，並比較受試組群之反應時間及反應正確率。
在行為特質測量上，變異數分析結果發現，與非犯罪人相較，情感性暴力犯的攻擊性、消極抵抗型性格違常、邊緣型性格違常、及反社會型性格違常均明顯較高；與非犯罪人相較，掠奪性暴力犯亦有明顯的反社會型性格違常；與掠奪性暴力犯相較，情感性暴力犯的消極抵抗型性格違常、依賴型性格違常、及邊緣型性格違常明顯較高；在4組受試類型中，性格違常程度達中度偏差及嚴重偏差程度者，以暴力犯所佔比例最高。在反社會性格違常上，情感性暴力犯有最強的反社會型性格違常，且情感性暴力犯及掠奪性暴力犯之反社會性格違常均達嚴重偏差程度。在大腦磁振造影上，暴力犯罪人顯示有較高的大腦結構組織不良率；在工作記憶及注意力作業表現則大致顯示額葉部位的功能過於低下，且顳葉、邊緣系統、扣帶皮質等區域的功能過於亢進之情形；在工作記憶之腦部反應則明顯低於非犯罪人。在反應時間上，與非犯罪人相較，無論是情感性暴力犯、掠奪性暴力犯、或是一般犯罪人，在工作記憶及注意力之正確命中反應時間均明顯較長。
暴力犯罪人由於缺乏足夠的工作記憶容量及注意力資源，在執行控制功能表現上顯示內容更新較慢的情形，此可能和其神經路徑的連結強度及訊息傳達速率有關，早期神經發展過程中較弱的連結及較慢的訊息傳達速率，均將使得個體日後在情緒性攻擊等反應抑制上產生問題，使渠等在面對外界挫折情境或未符期待的狀況時，易於傾向以改變外在事件來減少自身的認知失調，甚至以不計代價的攻擊性行為反應來使其目的獲得滿足，不斷的再犯行為進而持續發展成一種適應不良的性格傾向或心理特質。本研究在未來可藉由受試數目之提升及大腦特定區域結構之組織度檢驗，以獲得更大的生態效度並建構暴力犯罪行為之病因學模型。

關鍵字

暴力犯罪 ； 執行控制功能 ； 攻擊性 ； 反社會性格違常 ； 磁振造影

並列摘要

The problem and impact that violent crimes create for society are deep and far. It brings not only the enormous social cost, but also the public great fear to be victimized. The causes of violent crime are widely, and the explanation from biological, psychological, and sociological perspectives have its contribution. The primary purpose of this study was to investigate the distinguishing characteristics of violent offender through the behavior measures and the brain image technique. Based on the social cognitive neuroscience knowledge, this study attempt to provide the initiative finding of violent crime issues in Taiwan.
Through the biosocial approach, this study recruited 29 male subjects from the community. After reviewed the criminal history and sentence records, all the subjects were assigned to the affective-violent (VA) offender group, the predatory-violent (VP) offender group, the non-violent offender group, or the control group. Behavior measures in this study include the Barratt Impulsiveness Scale, the Buss-Durkee Hostility Inventory, and the Health, Personality, Habit Scale. Besides, MRI was adopted in the brain image acquisition. By using the structure MRI scan, the brain volume of gray matter, white matter, and cerebral spinal fluid were calculated, and the structure deficits of brain appearance were diagnosed. By using the functional MRI scan, the executive control functions of brain were measured, and the functional localization of working memory and attention were specified. All the reaction time and the response ratio were collected and analyzed from the experimental task.
The VA offender subjects were more likely to have higher scores of assault, passive resistance personality disorder, borderline personality disorder, and antisocial personality disorder than the control subjects. The VP offender subjects were more likely to have higher scores of antisocial personality disorder than the control subjects. The VA offender subjects were more likely to have higher scores of passive resistance personality disorder, dependent personality disorder, and borderline personality disorder than the VP offender subjects. The violent offender groups have the most members that meets the condition of moderately or severely degree between personality disorders, especially in the antisocial personality disorder. Besides, the violent groups shows more brain structure deficits and poor executive control functions. In general, the violent groups shows reduced frontal cortex function and higher activation in the temporal lobe, limbic system, and the cingulate cortex under the working memory and attention task. All the offender subjects were more likely to have longer reaction time of working memory and attention than the control subjects.
Limited by the working memory capacity and the attention resources, the violent offender subjects shows longer reaction time in the cerebral executive control function task. The results suggest that the deficit might be attributed to the weak linkage between the neural circuit, the disorganization of the neural fibers, or the slowly transmission rate of the neural tracts. The deficits that formed in the early neural development made the individuals to have poor response inhibition, and tend to change the external events to reduce the internal tension and cognitive dissonance when they meet frustration or unexpected situation. Due to the poor neural development, the individuals follow poor language expression ability, and tend to solve problem or fulfill their goals by physical or assault means. To recidivism in crimes by the individuals, kinds of non-adapted personality or specific mental attribution finally developed. However, it remains unclear whether impairment in executive control function is associated with violent crime. In the future study, the number of subjects should be increased to have better ecological validity, and the neurological examination of regional brain structure were necessary for the etiology explanation of the violent criminal behavior.

並列關鍵字

Violent crime ； Executive control function ； Assault ； Antisocial personality ； MRI

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