Mayall K, Humphreys G W, Mechelli A, Olson A, Price C J
School of Psychology, University of Leicester, UK.
J Cogn Neurosci. 2001 Aug 15;13(6):844-53. doi: 10.1162/08989290152541494.
The early stages of visual word recognition were investigated by scanning participants using PET as they took part in implicit and explicit reading tasks with visually disrupted stimuli. CaSe MiXiNg has been shown in behavioral studies to increase reaction times (RTs) in naming and other word recognition tasks. In this study, we found that during both an implicit (feature detection) task and an explicit word-naming task, mixed-case words compared to same-case words produced increased activation in an area of the right parietal cortex previously associated with visual attention. No effect of case was found in this area for pseudowords or consonant strings. Further, lowering the contrast of the stimuli slowed RTs as much as case mixing, but did not lead to the same increase in right parietal activation. No significant effect of case mixing was observed in left-hemisphere language areas. The results suggest that reading mixed-case words requires increased attentional processing. However, later word recognition processes may be relatively unaffected by the disruption in presentation.
通过正电子发射断层扫描（PET）对参与者进行扫描，研究视觉单词识别的早期阶段，当时他们参与了带有视觉干扰刺激的内隐和外显阅读任务。在行为研究中已经表明，大小写混合会增加命名和其他单词识别任务中的反应时间（RTs）。在本研究中，我们发现，在一项内隐（特征检测）任务和一项外显单词命名任务中，与相同大小写的单词相比，大小写混合的单词在先前与视觉注意相关的右顶叶皮层区域产生了增强的激活。对于假词或辅音串，在该区域未发现大小写的影响。此外，降低刺激的对比度与大小写混合一样会减慢反应时间，但不会导致右顶叶激活的相同增加。在左半球语言区域未观察到大小写混合的显著影响。结果表明，阅读大小写混合的单词需要增加注意力加工。然而，后期的单词识别过程可能相对不受呈现干扰的影响。
