稳态视觉刺激频率与诱发响应相关性的fMRI研究

稳态视觉诱发电位(SSVEP)及脑电逆问题(inverse EEG)的研究显示了大脑皮层对于不同频率的稳态视觉刺激的响应具有幅度及空间位置上的差异.本文利用功能性磁共振成像(fMRI)研究稳态视觉刺激频率与诱发响应之间的相关性.根据SSVEP的实验结果进行真fMRI实验设计,对5名被试者给予不同频率的稳态视觉刺激,同时进行了脑部的fMRI扫描,采用SPM软件进行数据处理和分析.结果显示,不同频率刺激下的响应区域均集中于初级视皮层(V1),并且均具有单侧优势效应,即右侧半球的响应强于左侧半球.该结果显示了初级视皮层单侧优势对于稳态视觉诱发响应的表现形式.本文讨论了单侧优势与刺激性质之间存在相关性的可能,以及对此做进一步研究和应用的前景.

Frequency dependence of visual evoked response: an fMRI study

Previous research on steady-state visual evoked potential(SSVEP) and inverse EEG shows amplitude and spatial differences of visual evoked response to steady-state visual stimulus of different frequencies.The fMRI experiments were employed to study the frequency dependence of visual evoked response in this paper.The experiments were designed according to SSVEP results,5 volunteers were scanned on MR scanner while they were presented visual stimulus of several frequencies to acquire fMRI data.Results of pre-processing and statistical analysis by SPM show unilateral dominance of response regions which displays the dominance representation in steady-state visual response.Possibility of relationship between the unilateral dominance and stimulus properties is discussed,as well as the perspectives of further research and application.