Chuanli Zang

The effect of visual complexity and word frequency on eye movements during Chinese reading

Eye movements of native Chinese readers were monitored when they read sentences containing single-character target words orthogonally manipulated for frequency and visual complexity (number of strokes). Both factors yielded strong main effects on skipping probability but no interaction, with readers skipping visually simple and high frequency words more often. However, an interaction between frequency and complexity was observed on the fixation times on the target words with longer fixations for the low frequency, visually complex words. The results demonstrate that visual complexity and frequency have independent influences on saccadic targeting behaviour during Chinese reading but jointly influence fixation durations and that these two factors differently impact fixation durations and saccade targeting during reading.

Effects of word frequency and visual complexity on eye movements of young and older Chinese readers

Research using alphabetic languages shows that, compared to young adults, older adults employ a risky reading strategy in which they are more likely to guess word identities and skip words to compensate for their slower processing of text. However, little is known about how ageing affects reading behaviour for naturally unspaced, logographic languages like Chinese. Accordingly, to assess the generality of age-related changes in reading strategy across different writing systems we undertook an eye movement investigation of adult age differences in Chinese reading. Participants read sentences containing a target word (a single Chinese character) that had a high or low frequency of usage and was constructed from either few or many character strokes, and so either visually simple or complex. Frequency and complexity produced similar patterns of influence for both age groups on skipping rates and fixation times for target words. Both groups therefore demonstrated sensitivity to these manipulations. But compared to the young adults, the older adults made more and longer fixations and more forward and backward eye movements overall. They also fixated the target words for longer, especially when these were visually complex. Crucially, the older adults skipped words less and made shorter progressive saccades. Therefore, in contrast with findings for alphabetic languages, older Chinese readers appear to use a careful reading strategy according to which they move their eyes cautiously along lines of text and skip words infrequently. We propose they use this more careful reading strategy to compensate for increased difficulty processing word boundaries in Chinese.

The use of probabilistic lexicality cues for word segmentation in Chinese reading

In an eye-tracking experiment we examined whether Chinese readers were sensitive to information concerning how often a Chinese character appears as a single-character word versus the first character in a two-character word, and whether readers use this information to segment words and adjust the amount of parafoveal processing of subsequent characters during reading. Participants read sentences containing a two-character target word with its first character more or less likely to be a single-character word. The boundary paradigm was used. The boundary appeared between the first character and the second character of the target word, and we manipulated whether readers saw an identity or a pseudocharacter preview of the second character of the target. Linear mixed-effects models revealed reduced preview benefit from the second character when the first character was more likely to be a single-character word. This suggests that Chinese readers use probabilistic combinatorial information about the likelihood of a Chinese character being single-character word or a two-character word online to modulate the extent of parafoveal processing.

Parafoveal Previews and Lexical Frequency in Natural Reading: Evidence from Eye Movements and Fixation-Related Potentials

Participants’ eye movements and electroencephalogram (EEG) signal were recorded as they read sentences displayed according to the gaze-contingent boundary paradigm. Two target words in each sentence were manipulated for lexical frequency (high vs. low frequency) and parafoveal preview of each target word (identical vs. string of random letters vs. string of Xs). Eye movement data revealed visual parafoveal-on-foveal (PoF) effects, as well as foveal visual and orthographic preview effects and word frequency effects. Fixation-related potentials (FRPs) showed visual and orthographic PoF effects as well as foveal visual and orthographic preview effects. Our results replicated the early preview positivity effect (Dimigen, Kliegl, & Sommer, 2012) in the X-string preview condition, and revealed different neural correlates associated with a preview comprised of a string of random letters relative to a string of Xs. The former effects seem likely to reflect difficulty associated with the integration of parafoveal and foveal information, as well as feature overlap, while the latter reflect inhibition, and potentially disruption, to processing underlying reading. Interestingly, and consistent with Kretzschmar, Schlesewsky, and Staub (2015), no frequency effect was reflected in the FRP measures. The findings provide insight into the neural correlates of parafoveal processing and written word recognition in reading and demonstrate the value of utilizing ecologically valid paradigms to study well established phenomena that occur as text is read naturally.

The role of character positional frequency on Chinese word learning during natural reading

Readers’ eye movements were recorded to examine the role of character positional frequency on Chinese lexical acquisition during reading and its possible modulation by word spacing. In Experiment 1, three types of pseudowords were constructed based on each character’s positional frequency, providing congruent, incongruent, and no positional word segmentation information. Each pseudoword was embedded into two sets of sentences, for the learning and the test phases. In the learning phase, half the participants read sentences in word-spaced format, and half in unspaced format. In the test phase, all participants read sentences in unspaced format. The results showed an inhibitory effect of character positional frequency upon the efficiency of word learning when processing incongruent pseudowords both in the learning and test phase, and also showed facilitatory effect of word spacing in the learning phase, but not at test. Most importantly, these two characteristics exerted independent influences on word segmentation. In Experiment 2, three analogous types of pseudowords were created whilst controlling for orthographic neighborhood size. The results of the two experiments were consistent, except that the effect of character positional frequency was absent in the test phase in Experiment 2. We argue that the positional frequency of a word’s constituent characters may influence the character-to-word assignment in a process that likely incorporates both lexical segmentation and identification.