Ingles Janet L, Eskes Gail A
School of Human Communication Disorders, Dalhousie University, Halifax, Canada.
J Int Neuropsychol Soc. 2008 Jan;14(1):164-73. doi: 10.1017/S1355617708080119.
The extent to which letter-by-letter reading results from a specific orthographic deficit, as compared with a nonspecific disturbance in basic visuoperceptual mechanisms, is unclear. The current study directly compared processing of letters and digits in a letter-by-letter reader, G.M., using a rapid serial visual presentation (RSVP) task and a speeded matching task. Comparisons were made to a group of six brain-damaged individuals without reading deficits. In the RSVP task, G.M. had increased difficulty reporting the target identities when they were letters, as compared with digits. Although this general pattern was also evident in the control group, the magnitude of the letter-digit accuracy difference was greater in G.M. Similarly, in the matching task, G.M. was slower to match letters than digits, relative to the control group, although his response times to both item types were increased. These data suggest that letter-by-letter reading, at least in this case, results from a visuoperceptual encoding deficit that particularly affects letters, but also extends to processing of digits to a lesser extent. Results are consistent with the notion that a left occipitotemporal area is specialized for letter processing with greater bilaterality in the visual processing of digits.
逐字母阅读是由特定的正字法缺陷导致的，还是与基本视觉感知机制中的非特定干扰有关，目前尚不清楚。本研究使用快速序列视觉呈现（RSVP）任务和快速匹配任务，直接比较了逐字母阅读者G.M.对字母和数字的加工情况。并与一组无阅读缺陷的脑损伤个体进行了比较。在RSVP任务中，与数字相比，G.M.在报告字母目标身份时困难增加。虽然这种总体模式在对照组中也很明显，但G.M.中字母-数字准确性差异的幅度更大。同样，在匹配任务中，相对于对照组，G.M.匹配字母的速度比匹配数字的速度慢，尽管他对两种类型项目的反应时间都增加了。这些数据表明，至少在这种情况下，逐字母阅读是由视觉感知编码缺陷导致的，这种缺陷特别影响字母，但在较小程度上也扩展到数字加工。研究结果与左枕颞区专门用于字母加工，而数字视觉加工具有更大双侧性的观点一致。
