MEG signal dynamics of chromatic motion mechanism

在本研究项目中，我利用脑磁图（MEG）系统研究了心理物理学和脑功能成像中的色运动机制。在心理实验中，我测试了二阶色差运动如何与二阶消色差运动相结合，以阐明运动机制的最后皮层阶段可以处理色差信息产生色差运动信号，或者将来自色心（可能是V4）的色差运动信号与消色差运动信号相结合。这一心理物理结果表明，最后阶段可以将二阶色差和消色差运动信号与时域窄调谐相结合，产生单一的相干运动感知。我还进行了心理实验，研究了s -cone在运动机制中的作用。结果表明，s锥细胞通过两种不同的途径促进运动：一种是通过色度途径的非线性运动机制，另一种是通过亮度途径的线性运动机制。脑磁图结果表明，信号的第一个峰值出现在视觉刺激开始后100毫秒。这与常规脑磁图实验结果一致。本课题可以从多个方面实现对色度运动机理的详细研究。然而，它并不是全色运动机构的图形。因此，有必要对后期相关的MEG信号进行分析，以找到整个色度运动机制。

In this research project, I investigated chromatic motion mechanism in psychophysics and functional brain imaging with the use of MEG (MagnetoEncephaloGram) system.In the psychological experiments, I tested how second-order chromatic motion was integrated with second-order achromatic motion to clarify that the final cortical stage for motion mechanism can deal with chromatic information to produce chromatic motion signal or integrate chromatic motion signal coming from color center, probably V4, with achromatic motion signal. Results in this psychophysics indicate that the final stage can integrate second-order chromatic and achromatic motion signal with the narrow tuned in temporal frequency domain and produce a single coherent motion perception. I also carried out psychological experiment in which I investigated how S-cones contribute to motion mechanism. The results show that S-cones contribute to motion via two different pathways : a non-linear motion mechanism via a chromatic pathway and a linear motion mechanism via a luminance pathway.Results in MEG shows that the first peak of the signal occurs at 100 msec from onset of the visual stimuli. This is consistent with the results of conventional MEG experiments.This research project could achieve to find the detail of the chromatic motion mechanism in many of aspects. However, it is not the whole figure of the chromatic motion mechanism. It is therefore necessary to analyze MEG signals related on later stage in order to find the whole chromatic motion mechanism.