The perceptual span and oculomotor activity during the reading of Chinese sentences.

Eye-movement-contingent display changes were used to control the visibility of characters during the reading of Chinese text. Characters outside a window of legible text were masked by dissimilar characters, and effects of viewing constraints were ascertained in several oculomotor measures. The results revealed an asymmetric perceptual span that extended 1 character to the left of the fixated character and 3 characters to its right. The size of right-directed saccades extended across 2 to 2 1/2 character spaces, indicating that the perceptual spans of successive fixations overlapped slightly and that some linguistic information was integrated across fixations. The relatively small spatial overlap of successive spans appears to reflect a text-specific process. However, the results also revealed substantial similarities in the coding of morphographic Chinese and alphabetic English texts, indicating that text-specific coding routines are subordinated to general coding principles.