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

为探讨颞叶切除术（TL）对语言功能的影响及语言优势半球，对36例正常人和12例接受左侧或右侧TL（LTL=7，RTL=5）的患者进行了事件相关电位（ERP）记录。用速示器和“oddball”范式呈现视觉言语刺激（“假名”）和非言语刺激（“空间点”和“面孔”），正常被试（右利手）右视野言语刺激和左视野非言语刺激的P300幅值较高。在言语刺激（或非言语刺激）时，右视野刺激（RV）-右手反应（RH）反应时最短（或最长），其次是RV-LH、LV-RH和LV-LH。LTL和RTL患者P300潜伏期均较正常人延长，尤以“假名”和“圆点”刺激延长最为明显。这些结果提示，P300和对速示视觉刺激的反应时可以决定TL的半球优势和效应，结合脑磁图和功能磁共振成像的进一步研究将对TL的认知功能进行精确定位。

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.