Sensitivity to configural information and expertise in visual word recognition

Holistic processing has been regarded as a marker of perceptual expertise for many object categories. However, visual word processing, a common form of perceptual expertise in the population, is traditionally considered part-based instead of holistic, and whether it involves holistic processing remains inconclusive. In 4 experiments, we examined a well-known yet less studied indicator of holistic word processing-observers' sensitivity to changes in configural information of objects. A paradigm was designed with 2 crucial elements: specific requirement to process configural information within a word and an inversion manipulation. Experiments 1 and 2 showed that experienced observers were more sensitive to configural changes when words were presented in the familiar upright than unfamiliar inverted orientation. Of importance, such an inversion effect was correlated with one's fluency in word recognition in 1 of the conditions (nonnative Chinese readers viewing Chinese characters) where there was a larger variability in word recognition fluency. Experiments 3 and 4 compared sensitivity to configural and component changes in word processing, showing that expert readers were more sensitive to configural changes than component changes (defined as line thickness of parts) in words. The current findings suggest that, similar to face recognition and other domains of perceptual expertise, word recognition involves holistic processing. Instead of being a hallmark of face recognition, holistic processing is a general expertise marker shared by different domains of perceptual expertise.