以事件相關電位檢視暴力青少年的抑制與錯誤監控機制

Using event-related potentials to examine error processing and inhibitory control in juvenile violent offenders

本研究之目的是欲檢視暴力行為與錯誤監控及抑制控制歷程之相關性，以暴力青少年為主要研究之對象，為了瞭解他們攻擊行為背後的成因，本研究結合旁側干擾作業與停止訊號作業，採用腦波儀，比較衝動型暴力青少年與一般青少年在反應抑制、錯誤偵測與錯誤後補償歷程上，是否具有行為與電生理的差異。行為結果顯示，實驗組在衝突或一般情境之下的停止訊號反應時間(stop signal reaction time,SSRT)都顯著地比控制組長，這可能顯示他們抑制能力較差。暴力青少年組在抑制失敗之後，並未出現如控制組一般的錯誤後減慢行為表現。腦波實驗結果顯示，在執行目標GO作業嘗試的情況下，實驗組與控制組在G0 N2的振幅並無顯著差異。而在成功抑制的狀況下，發現實驗組有較小的Stop N2與較大的Stop P3。較長的SSRT與較小的N2振幅，顯示他們的抑制效率較差，比起一般青少年需要花更長的時間來抑制不當行為；而較大的P3與ERN則可能與他們的衝動特質以及負面情緒特質相關。他們沒有錯誤後減慢的行為表現，以及在失敗抑制的情況下，發現實驗組產生較大的錯誤關聯負波(error-related potentials, ERN/Ne)，而兩組的錯誤相關正波(error positivity,Pe)則無顯著差異，這表示暴力青少年雖然能有效偵測錯誤，但卻無法有效處理相關訊息以進行後續的行為調整，導致他們比一般人更容易重蹈覆轍。

The aims of present study were to use a stop signal paradigm combined with event-related potentials to investigate error processing and inhibitory control in juvenile violent offenders. The participants included 20 impulsive violent juvenile offenders from reform schools and 20 matched controls from high schools. The two groups were compared on aspects of behavioral performance including overt reaction time (Go RT), stop signal reaction time (SSRT) and post-error slowing. The violent group had both longer Go RTs and SSRTs than matched controls. These behavioral results showed the violent adolescents might have poorer inhibitory control. Compared to the control group, the usual post-error slowing was not seen in violent adolescents, showing they possibly have deficient behavior adjustment after error responses. The results of event-related potential analysis showed reduced N2 and enhanced P3 components in the violent group when inhibiting successfully, similar to the patterns seen in highly impulsively violent adults. In unsuccessful stop trials, the violent group showed higher ERN amplitudespresumably resulting from higher negative emotion. There were no group differencesfor theerror positivity, Pe, component. These results suggest that violent juvenile offenders can detect errorsas well as controls but are impaired in error correction. This deficit could be attributed to inefficient inhibition and error processing and by modulated by negative emotion.