緊急駕駛行為下之大腦抑制過程之運作

Abstract

開車過程中，突發的緊急情況，對於駕駛者而言，是很難去妥善反應，常會造成車禍發生以及人員傷亡。許多因素皆會影響緊急駕駛，尤其如何有效抑制行為最為重要。因此，本研究即是探討突發狀況時，駕駛者大腦內部抑制機制的運作歷程，除了瞭解相對應的行為變化外，並欲找出相關之大腦特徵。本研究根據終止信號作業(Stop Signal Task)設計出兩個開車實驗，並於虛擬實境技術建構出的擬真駕駛環境下，探討大腦抑制機制的運作。實驗中記錄腦電波訊號，並利用獨立成分分析方法(Independent Component Analysis)，將腦電波分離出互相獨立的訊號源，並透過事件相關頻譜擾動(Event-related Spectral Perturbation)觀察腦電波在頻率和時間上的變化。結果發現，在駕駛中遭遇緊急狀況時，大腦反應的抑制運作過程會使前腦區與中腦區δ頻帶(1-3Hz)及θ頻帶(4-7Hz)的能量上升；但過去被當作動作抑制指標的β頻帶並未發現於緊急駕駛狀況下。另外，藉由比較抑制成功與抑制失敗兩種狀況，發現中央腦區δ頻帶(1-3Hz)的能量變化，似乎可做為，預測駕駛者在緊急狀況下，行為抑制成功與否的大腦指標。

Emergency situations while driving is difficult for driver to deal with, and it might lead to a critical damage for drivers. In this study, we aim to obtain a better and precise understanding of brain activities of inhibition mechanism in emergencies situations, which is of great benefit for devolvement of driving assistant system. Two virtual realistic driving experiments based on stop signal paradigm were performed for 15 subjects to study Electroencephalography (EEG) brain dynamics. In addition, Independent component analysis (ICA) and event-related spectral perturbation (ERSP) analysis were applied for investigating power changes in emergency driving. We found that theta (4-7Hz) and delta (1-3Hz) power increases in Frontal and Central areas reflect inhibition process. In previous inhibition studies, beta power increase in Frontal area was also related to inhibition response. However, our results suggest that this power change in Frontal area might not be a reliable EEG characteristic of inhibition in emergency driving. Furthermore, by comparing successful and unsuccessful inhibition, this study found that delta band power activities in Central area could be an EEG index for implementing prediction systems.