Meyler Ann, Breznitz Zvia
Department of Psychology, Center for Cognitive Brain Imaging, Carnegie Mellon University, Pittsburgh, PA 15123, USA.
J Genet Psychol. 2005 Jun;166(2):215-38. doi: 10.3200/GNTP.166.2.215-240.
The authors examined the processing of phonological and orthographic word representations among 17 dyslexic and 16 normal college-level readers using Event-Related Potential measures. They focused on 2 early components--the P200 and the P300. The results revealed P200 and P300 components of lower amplitude and later latency among dyslexic readers than among normal readers for both types of word representation. Group differences were greatest for phonological representations. In addition, the authors observed greater time gaps among dyslexic readers than among normal readers between different processing stages (i.e., between P2 and P3 peaks, between P3 and reaction time). Combined, the data suggest a consistent speed-of-processing deficit among dyslexic readers that is evident within and between stages of cognitive processing. The results are discussed in the context of deficits in stimulus encoding and working memory. In addition, the authors discuss the need for accurate timing and synchronization of phonological and orthographic codes for efficient word recognition.
作者使用事件相关电位测量方法，对17名诵读困难的大学生读者和16名正常大学生读者的语音和正字法单词表征处理过程进行了研究。他们重点关注了两个早期成分——P200和P300。结果显示，对于两种类型的单词表征，诵读困难读者的P200和P300成分的波幅较低，潜伏期较晚。语音表征的组间差异最大。此外，作者观察到，诵读困难读者不同处理阶段（即P2和P3波峰之间、P3和反应时间之间）的时间间隔比正常读者更大。综合来看，数据表明诵读困难读者存在一致的处理速度缺陷，这在认知处理阶段内和阶段之间都很明显。研究结果在刺激编码和工作记忆缺陷的背景下进行了讨论。此外，作者讨论了为实现高效单词识别，语音和正字法编码的准确计时和同步的必要性。
