知觉质量对汉字心理旋转事件相关电位P300的影响

Influence of perceptional quality of stimulus on event-related potential P300 during mental rotation

目的:探讨视觉干扰对被试心理旋转加工的影响.方法:8名健康男性大学生完成以未加背景干扰和加入背景干扰的汉字为刺激的心理旋转任务时,记录反应时和事件相关电位波形.结果:未加视觉干扰与加入视觉干扰图片相比,随着从0°旋转至180°,Pz点P300平均波幅从(13.3±2.6)μV变化为(10.8±1.9)μV;潜伏期从(504±65)ms变化为(601±53)ms,潜伏期存在显著差异(P<0.05).Cz点P300平均波幅从(9.8±2.3)μV变化为(9.0±2.8)μV;潜伏期从(561±52)ms变化为(614±56)ms,存在显著差异(P<0.05).结论:P300波幅随心理旋转加工角度的增加而负向漂移.降低知觉质量,推后心理旋转,P300的波幅改变被推后.

AIM： To observe the effects of visual noise on the mental rotation. METHODS： The reaction time and eventrelated potentials （ERP） were recorded when 8 healthy male college students were tested by mental rotation task. Stimuli were white words on a black background without visual noise and white words on a gray background with visual noise. RESULTS： With the increase of the rotation angle from 0° to 180° the average amplitude of P300 in Pz changed from （ 13.3 ± 2. 6 ） uV to （10.8 ± 1.9） uV. The average latency of P300 changed from （504 ±65） ms to （601 ±53） ms; there was significant difference in the latency （P 〈 0.05 ）. The average amplitude of P300 in Cz changed from （9.8 ± 2.3 ） uV to （ 9.0 ± 2.8 ） uV. The average latency of P300 changed from （561 ±52） ms to （614 ±56） ms; there was significant difference in the average latency （P 〈 0.05 ）. CONCLUSION： With the increase of rotation angle ,the amplitude of P300 becomes more negative. The reduced perceptual quality delays the onset of the mental rotation, and the onset of the amplitude modulation of P300 was also delayed.