Polianskiĭ V B, Evtikhin D V, Sokolov E N
Lomonosov State University, Moscow.
Zh Vyssh Nerv Deiat Im I P Pavlova. 2003 Jan-Feb;53(1):51-61.
The oddball paradigm was applied in experiments with waking rabbits using rare (deviant) and frequent (standard) stimuli, which were similar in color but different in intensity, deviant ones being of lower intensity. In addition, the VEPs to the single deviants were averaged. Such single deviants (without standard stimuli) were given at the beginning and at the end of the stimulation. The positivity of cortical and hippocampal visual evoked potentials to deviant stimuli increased in comparison to responses to standards and single deviants. The VEP-peaks P1 and P2 in the visual cortex and the VEP P1, N1 and P2 peaks in hippocampus increased. The most prominent significant changes were demonstrated for cortical VEP P2 (P130) peak. It is suggested that the increase of positivity to oddball deviants is due to the orienting reflex arising in response to rare stimuli. The increase of P2-peak can be connected with the transfer of information signaling changes of light intensity. It was demonstrated that the most clear and contrast differences in the VEPs to deviants and standards took place for the case of minimal distinction in their intensities. This fact may reflect the orienting reactionto threshold stimuli.
在对清醒兔子进行的实验中应用了异常球范式，使用了稀有（偏差）和频繁（标准）刺激，这些刺激颜色相似但强度不同，偏差刺激强度较低。此外，对单个偏差刺激的视觉诱发电位进行了平均。这种单个偏差刺激（无标准刺激）在刺激开始和结束时给出。与对标准刺激和单个偏差刺激的反应相比，皮层和海马体对偏差刺激的视觉诱发电位的阳性反应增加。视觉皮层中的VEP峰P1和P2以及海马体中的VEP P1、N1和P2峰增加。皮层VEP P2（P130）峰表现出最显著的变化。有人认为，对异常球偏差刺激的阳性反应增加是由于对稀有刺激产生的定向反射。P2峰的增加可能与光强度变化的信息信号传递有关。结果表明，在偏差刺激和标准刺激的强度差异最小时，VEP中最清晰和明显的差异出现。这一事实可能反映了对阈刺激的定向反应。
