关键词: 知觉广度, 副中央凹预视, 眼动

Abstract: The amount of information that can be acquired in foveal and parafoveal vision is one of the most fundamental issues in the study of eye movement control in reading. This refers to the perceptual span, which is a measure of the portion of a line of text from which a reader can extract useful visual and linguistic information to facilitate reading on any single fixation (McConkie & Rayner, 1975). A skilled adult reader can acquire useful information from the word to the right of the fixated word; this was referred to as parafoveal preview effect (Rayner, 1975, 1998, 2009). Rayner (1986) found that as reading skill improves, the amount of information that can be extracted from upcoming words during a single fixation increases. Chace (2005) found that reading skill also modulated the preview effecting adult readers. In the present study, parafoveal preview effect was investigated in Chinese fifth graders and college students.
Two experiments were conducted using the eye-movement contingent display change technique. 20 fifth graders and 20 college students participated. Their eye movements were recorded with a SR Research EyeLink eye tracker. Eighty sentences were presented in eight viewing conditions (R0、R1、R2、R3、R4、L1R4、L2R4 and whole line) were included to examine the perceptual span of fifth graders and college students in Experiment 1. In Experiment 2, four preview types (identical, homophone, orthographic, control and random) were used to explore the parafoveal preview effect of fifth graders and college students.
The results showed that the perceptual span of college students was larger than that of the fifth graders. Orthographic and phonological information could be obtained by college students, while only orthographic information could be obtained by fifth graders in parafoveal preview.
In summary, the present study indicated that different information is acquired during fixations by college students and fifth graders. College students read more quickly than the fifth graders; one possible reason for this is that they have a larger perceptual span and acquire more orthographic and linguistic information from upcoming words than fifth graders do.

Key words: perceptual span, parafoveal preview, eye movements