Lindell Annukka K, Arend Isabel, Ward Robert, Norton Jennifer, Wathan Jennifer
School of Psychology, University of Wales, Bangor, Gwynedd, UK.
Laterality. 2007 Nov;12(6):543-58. doi: 10.1080/13576500701495190.
Although the definitive source of the left hemisphere's superiority for visual word recognition remains illusive, some argue that the left (LH) and right (RH) hemispheres engage different strategies during early perceptual processes involved in stimulus encoding. In particular, it is proposed that the LH treats a word as a unitary perceptual group whereas the RH processes the letters comprising a word as a series of individual perceptual units. The present study investigated support for this processing distinction by examining hemispheric strategies for temporal integration using Prinzmetal and Millis-Wright's (1984) feature-binding paradigm. A total of 20 participants identified the colour and identity of a target letter, presented within a three-letter word (e.g., ART) or nonword (e.g., HRF), directed to their left or right visual field. Errors were classified on the basis of whether they involved substitution of a colour present within the stimulus but at a different location (ON error), or the substitution of a colour not present within the stimulus (OFF error). As anticipated, for word stimuli there was a higher proportion of OFF errors associated with trials directed to the RH, consistent with the notion that the LH treats words as single perceptual units and is hence biased toward miscombination of perceptual information present within the stimulus. The pattern of ON errors across stimulus type provided clear evidence of RH sequential encoding effects, with the number of errors increasing markedly across the ordinal position of the letters comprising the stimulus string. As such, these data provide new evidence that the LH's advantage for visual word recognition arises, at least in part, from the ability to encode verbal stimuli as single perceptual units.
尽管左半球在视觉单词识别方面具有优势的确切来源仍然难以捉摸，但一些人认为，在涉及刺激编码的早期感知过程中，左（LH）半球和右（RH）半球采用了不同的策略。特别是，有人提出，左半球将单词视为一个统一的感知组，而右半球则将构成单词的字母作为一系列单独的感知单元进行处理。本研究通过使用普林兹梅尔和米利斯 - 赖特（1984）的特征绑定范式来研究半球时间整合策略，以探究对这种处理差异的支持。共有20名参与者识别呈现于三字母单词（如ART）或非单词（如HRF）中的目标字母的颜色和身份，这些刺激指向他们的左视野或右视野。错误根据其是否涉及将刺激中存在但位于不同位置的颜色进行替换（ON错误），或者将刺激中不存在的颜色进行替换（OFF错误）来分类。正如预期的那样，对于单词刺激，与指向右半球的试验相关的OFF错误比例更高，这与左半球将单词视为单个感知单元并因此倾向于对刺激中存在的感知信息进行错误组合的观点一致。跨刺激类型的ON错误模式提供了右半球顺序编码效应的明确证据，随着构成刺激字符串的字母顺序位置的增加，错误数量显著增加。因此，这些数据提供了新的证据，表明左半球在视觉单词识别方面的优势至少部分源于将言语刺激编码为单个感知单元的能力。
