Azizian Allen, Watson Todd D, Parvaz Muhammad A, Squires Nancy K
Laboratory of Molecular Neuroimaging, Neuropsychiatric Institute, University California Los Angeles, UCLA, USA.
Brain Topogr. 2006 Spring;18(3):213-22. doi: 10.1007/s10548-006-0270-9. Epub 2006 Mar 1.
A substantial body of research suggests that the cognitive mechanisms for picture and word processes are functionally and anatomically distinct. In spite of significant advancements in the understanding of pictures and words, the electrophysiological activities mediating these processes are not well known. To address this issue, we examined event-related brain potentials (ERPs) to pictures and their printed names in a modified dual-target oddball task. ERPs were recorded while participants classified schematic pictures and their corresponding names into target and nontarget categories. Results showed that pictures and words were associated with electrophysiological responses that differed temporally and topographically. In comparison to words, P300s to pictures were characterized by shorter latency and larger amplitude at parietal electrodes. In contrast, words produced greater P200 amplitude at frontal areas. The results are consistent with the view that categorization of pictures is faster than words. Findings are discussed in relation to stimulus evaluation and the time course for picture and word classification.
大量研究表明，图片和文字处理的认知机制在功能和解剖学上是不同的。尽管在对图片和文字的理解方面取得了重大进展，但介导这些过程的电生理活动却并不为人所知。为了解决这个问题，我们在一个改良的双目标Oddball任务中，研究了对图片及其印刷名称的事件相关脑电位（ERP）。在参与者将示意性图片及其相应名称分类为目标和非目标类别时，记录ERP。结果表明，图片和文字与在时间和地形上不同的电生理反应相关。与文字相比，对图片的P300在顶叶电极处具有潜伏期较短和波幅较大的特征。相反，文字在额叶区域产生更大的P200波幅。结果与图片分类比文字更快的观点一致。结合刺激评估以及图片和文字分类的时间进程对研究结果进行了讨论。
