Determination of hemispheric dominance using visual event-related potentials (ERPs)

对36例正常人和12例接受左侧或右侧颞叶切除(LTL=7，RTL=5)的患者进行了事件相关电位(ERP)检测，以确定语言的优势半球和颞叶切除(TL)的效果。采用速测仪和“古怪”范式分别呈现语言刺激(“假名”)和非语言刺激(“点”在空间和“面”)的视觉刺激，正常受试者(右利手)在语言刺激右视野和非语言刺激左视野时P300波幅较高。当存在语言(或非语言)刺激时，右侧视野刺激(RV)-右手反应(RH)的反应时最短(或最长)，其次是RV-LH、LV-LH和LV-LH。在接受TL的患者中，P300波幅低于正常受试者，且未见大脑半球对语言和非语言刺激的优势。LTL和RTL患者的P300潜伏期均较正常人延长，尤其是LTL的“Kana”刺激和RTL患者的“Dot”刺激。这些结果表明，P300和对速视视觉刺激的反应时可以决定TL的大脑半球优势和效应，结合脑磁图和功能MRI的进一步研究将对认知功能进行准确的定位。

In order to determine the dominant hemisphere of language and the effect of the temporal lobectomy (TL), event-related potentials (ERP) were recorded in 36 normal subjects and 12 patients received left or right TL (LTL=7, RTL=5). Visual stimuli of verbal ("Kana") and non-verbal ("Dot" in space and "Face") were presented using a tachistoscope and "oddball" paradigm.In normal subjects (right handers), the P300 amplitude were higher in verbal stimulation to right-visual field and in non-verbal stimulation to left-visual field. When verbal (or non-verbal) stimulus was presented, reaction time was shortest (or longest) in right-visual field stimulus (RV)-right hand response (RH), followed by RV-LH,LV-RH,and LV-LH.In patients received TL,P300 amplitude were lower than normal subjects, and hemispheric dominance to verbal and non-verbal stimuli were not observed. Both LTL and RTL patients had longer P300 latency than normal subjects, especially in "Kana" stimulus in LTL and "Dot" in RTL patients. Thses findings suggest that P300 and reaction time to the tachistoscopic visual stimuli could determine the hemispheric dominance and effect of TL.Further study in combination with magnetoencephalography and functional MRI would produce precise localization of cognitive function.