不同注意状态对视敏度ERP检测的影响

Effect of Different Attentional Conditions on ERP Detection of Visual Acuity

目的研究不同注意状态对视敏度相关视觉信息刺激所产生事件相关电位(event-related potential,ERP)成分的影响,为法医临床学视觉客观评价提供理论参考。方法以视敏度图标作为视觉信息刺激范式,以15名志愿者作为研究对象,嘱其在视觉刺激注意状态下对视敏度图标进行计数,在视觉刺激非注意状态下认真收听有声故事并在实验结束后回答故事相关问题,应用32导ERP系统记录两种不同注意状态下受试者ERP结果。结果在两种注意状态下,阈上视敏度图标均引出了P_1和P_(300)成分,但阈下刺激图标只引出P_1成分,未引出P_(300)波形;在阈上图标所引出的ERP波形中,视觉刺激注意时的P_1、P_(300)振幅高于非注意时P_1、P_(300)振幅。结论注意状态影响视敏度检测,P_(300)成分也可以用于视觉刺激非注意状态下阈上及阈下视敏度水平的鉴别。

Objective To study the effect of different attentional conditions on the event-related potential （ERP） components generated by the visual information stimuli related to visual acuity, and provide a theoretical reference for clinical forensic visual objective evaluation. Methods With visual acuity opto-types as normal form of visual information stimuli,15 volunteers as study subjects were supposed to ac-count the visual acuity optotypes under the attentional condition of visual stimuli. Furthermore, the sub-jects were required to listen to the storytelling carefully under the non-attentional condition of visual stimuli, and after the examination, they needed to answer the story-related questions. All the EEG re-sults of two different attentional conditions from the subjects were recorded by 32 channel ERP system. Results Under two attentional conditions, P1 and P300 components were evoked by the visual acuity opto-types on supra-threshold and threshold visual acuity levels, while only Pi component were evoked by the visual acuity optotypes on sub-threshold levels. In the ERP waveforms evoked by the visual acuity optotypes on supra-threshold, P1 and P300 amplitudes under attentional condition were larger than that un-der non-attentional condition. Conclusion Attentional conditions can influence the detection of visual acuity. P300 component can be used to distinguish the visual acuity levels with supra-threshold and sub-threshold under non-attentional condition.