During reading, readers make eye movements to bring new information into the fovea, the region of highest visual acuity, which spans the central 2° of the visual field (
Rayner, 1998). Visual acuity declines rapidly with the increase in distance from fixation in the parafoveal region (which spans 2°–5° of the visual field). Despite reduced acuity, readers can still extract information from the parafoveal region, a process known as parafoveal preview (
Rayner, 2009).
Previous research on parafoveal preview has primarily focused on two issues: first, the range of useful information readers can extract during a fixation, also referred to as the perceptual span (
McConkie & Rayner, 1975), and second, what types of preview information—orthographic, phonological, or semantic—readers can extract from the parafovea (
Schotter et al., 2012). Eye-movement studies have shown that the perceptual span, in Chinese—where the character is the basic written unit—extends one character to the left and three characters to the right of fixation (
Inhoff & Liu, 1998). Most research on preview types has examined the first or second character to the right of fixation (i.e., characters at the N + 1 or N + 2 position). However, it remains unclear whether readers can also effectively obtain orthographic information, and possibly higher-level phonological or semantic information, from the third character to the right of fixation (i.e., the character at the N + 3 position). The present study was designed to address this issue.
1.1. Parafoveal Preview in Alphabetic Writing Systems
From the first word to the right of fixation (i.e., word N + 1), studies have shown that readers can extract orthographic information (
Johnson et al., 2007;
Milledge et al., 2021,
2022;
Rayner et al., 1986) as well as phonological information (
Ashby et al., 2006;
Chace et al., 2005;
Miellet & Sparrow, 2004;
Milledge et al., 2022). However, there remains considerable debate regarding whether readers can obtain semantic information during reading (
Y. Pan et al., 2024).
Rusich et al. (
2020) employed a rapid parallel visual presentation (RPVP) paradigm to investigate parafoveal semantic preview in Italian. Two words were presented simultaneously in this paradigm, with one in the foveal region and the other in the parafoveal region. By manipulating the semantic relatedness between the two words, they found that readers were able to extract semantic information from word N + 1. Building on this,
Primativo et al. (
2022) further demonstrated that this semantic preview effect occurs within a very short time window, with semantic information being activated within 100 ms of parafoveal word presentation.
Hohenstein and Kliegl (
2014) also reported semantic preview effects in German using a boundary paradigm, showing that readers were able to extract semantic information from word N + 1 by comparing semantically related and unrelated previews. In contrast,
Rayner et al. (
2014), employing the same paradigm, found no evidence of semantic preview effects in English. This discrepancy could be explained by cross-linguistic differences in orthographic depth. Compared to Italian and German, English has a deeper orthography (
Ziegler & Goswami, 2005), which demands greater resources for phonological decoding and consequently leaves fewer resources available for higher-level semantic processing from the upcoming word (
Schotter, 2013).
For the second word to the right of fixation (i.e., word N + 2), meta-analytic evidence suggests that readers can extract preview information (
Vasilev & Angele, 2017). Some studies have shown that when the word N + 1 is short (e.g., a three-letter word), readers are able to effectively extract preview information from word N + 2 (
Kliegl et al., 2007;
Radach et al., 2013). In contrast, other studies have reported no preview effects from word N + 2 (
Angele et al., 2008;
Altarriba et al., 2001;
Vasilev & Angele, 2017), indicating that word length is an important factor influencing parafoveal preview. In addition,
Cutter et al. (
2014) investigated parafoveal processing of word N + 2 using compound words (e.g., teddy bear) as parafoveal stimuli. They found that readers were able to extract information from the second constituent (e.g., bear). This effect is thought to arise because the two constituents of a compound word can be represented as a single unit in the mental lexicon and processed as an integrated whole during sentence reading, thereby allowing readers to obtain a preview benefit from word N + 2.
1.2. Parafoveal Preview in Chinese
Findings from alphabetic writing systems cannot be directly generalized to Chinese, given its unique visual and linguistic characteristics. First, Chinese is unspaced and visually dense, with square-shaped characters. Second, as a logographic writing system, Chinese exhibits a relatively high degree of semantic transparency. These characteristics may facilitate the extraction of parafoveal information, particularly higher-level semantic information (
Hoosain, 1991). This raises an important question: What types of information can Chinese readers extract from the parafoveal region within their perceptual span?
Previous studies have shown that Chinese readers can extract certain types of information from parafoveal characters within their perceptual span (
Schotter et al., 2012;
Vasilev & Angele, 2017). Given that the perceptual span in Chinese reading is typically defined at the character level, and each character simultaneously conveys orthographic, phonological, and semantic information, the following section summarizes the types of information that readers can obtain from parafoveal characters within the perceptual span.
Regarding the first character to the right of fixation (i.e., character N + 1), there is substantial evidence that Chinese readers can extract orthographic (
Liu et al., 2002;
Zhang et al., 2024), phonological (
Liu et al., 2002;
Pollatsek et al., 2000;
J.-L. Tsai et al., 2004), and semantic information (
Yan et al., 2009;
J. Tsai et al., 2012;
Zhang et al., 2024).
Findings regarding the second character to the right of fixation (i.e., character N + 2) are more mixed. Some studies have demonstrated that readers can extract information from this position (
Yan et al., 2010;
Yang et al., 2012), whereas others suggest that preview effects emerge only when the character N + 1 is of high frequency (
Yang et al., 2009;
Yang et al., 2012), indicating that parafoveal processing of N + 2 is conditional. Further work has examined the type of information available at this position. For example,
Bai et al. (
2015) showed that when character N + 2 was orthographically similar rather than dissimilar to character N + 1, fixation durations on character N + 1 were shorter, suggesting that Chinese readers can extract orthographic information from character N + 2.
Most research on the third character to the right of fixation (i.e., character N + 3) has examined parafoveal processing in the context of multi-constituent units such as idioms.
Zang (
2019) proposed the Multi-Constituent Unit (MCU) Hypothesis, which argues that certain multi-word expressions, such as idioms, may be lexicalized and represented as a single lexical representation in the mental lexicon. For instance, the frequently used Chinese idiom 铁饭碗 (literally “iron rice bowl”, meaning “a secure job”) (
Zang et al., 2024a) illustrates this point. Consistent with this account,
Zang et al. (
2021) used three-character idioms as parafoveal preview stimuli and found that readers could extract information from the third character (e.g., 碗 in 铁饭碗).
Zang et al. (
2024b) similarly employed four-character idioms (e.g., 风雨同舟, literally “sharing a boat in stormy weather”, meaning “stand together through hardships”) and reported that readers could successfully preview information from the final constituent (e.g., 同舟).
The above findings provide strong evidence that Chinese readers can extract parafoveal information from as far as the third or even fourth character to the right of fixation. However, these preview effects have been observed primarily in idioms or other highly lexicalized multi-character units, suggesting that the benefit may depend heavily on lexicalized structure or familiarity. Moreover, most prior studies have focused simply on whether readers could obtain parafoveal information from distant parafoveal characters, without clarifying the specific types of information involved. Consequently, it remains unclear whether readers can reliably extract orthographic, phonological, and semantic information from Chinese characters at a more distant position (e.g., character at the N + 3 position). Addressing this question is therefore essential for advancing our understanding of the mechanisms underlying parafoveal preview processing.
1.3. Parafoveal Priming Study
A variety of experimental paradigms have been developed to investigate parafoveal preview. Some studies have examined preview effects during sentence reading and demonstrated that these effects can be influenced by sentence-specific characteristics. On the one hand, the semantic plausibility of a sentence can affect the extraction of parafoveal information. For example,
Schotter and Jia (
2016) reported that semantic preview effects only emerged under semantically plausible conditions, raising the question of whether the observed effects reflect genuine semantic pre-processing or merely predictions based on context (
Rusich et al., 2020). On the other hand, the processing demands of other words in a sentence can also modulate preview effects. For example,
Yang et al. (
2009,
2012) reported that preview effects at word N + 2 only occurred when word N + 1 was high-frequency, suggesting that a relatively low processing load is a prerequisite for extracting information from parafoveal words.
Some studies have employed the parafoveal priming paradigm to investigate parafoveal preview (
Khelifi et al., 2015;
Kwantes & Mewhort, 2002;
Pollatsek et al., 2000;
Rayner et al., 1978;
Veldre et al., 2023). In this paradigm, a preview word is briefly presented in the parafoveal region before the target word appears, and the preview can be orthographically, phonologically, or semantically similar or dissimilar to the target. A related preview influencing processing of the target compared with an unrelated preview, as reflected in reaction times or accuracy, indicates that information from the preview word has been partially pre-processed.
Snell et al. (
2018) further validated the effectiveness of this paradigm in two experiments. In a sentence reading task (Experiment 1), no semantic preview effects were observed. However, in a lexical decision task using the parafoveal priming paradigm (Experiment 2), significant semantic priming effects were found, suggesting that readers can extract parafoveal semantic information when words are presented outside of a sentence context.
Pollatsek et al. (
2000) applied this paradigm to investigate parafoveal processing of Chinese characters. Their results indicated that Chinese readers could extract orthographic and phonological information from parafoveal characters but not semantic information. However, as noted by
Pollatsek et al. (
2000), the study had two limitations. First, the preview characters were presented at a relatively large eccentricity (4.7° to the right of fixation), which may have attenuated the preview effects due to reduced visual acuity. Second, participants had to deliberately shift their gaze to the parafoveal region, making it difficult to precisely control the preview duration for each character. Given that the preview duration is a critical factor affecting parafoveal processing (
Hohenstein et al., 2010;
J. Pan et al., 2020), the results of
Pollatsek et al. (
2000) may have underestimated Chinese readers’ ability to extract information from parafoveal characters.
1.4. The Current Study
In summary, research on parafoveal processing of distant Chinese characters and the types of information that readers can extract remains in its early stages. Visual acuity drops off rapidly in the parafoveal region as distance from fixation increases, resulting in substantial reductions in both processing efficiency and word recognition accuracy (
Veldre et al., 2023). This raises the question of whether readers’ visual acuity and attentional resources are sufficient to support the extraction of orthographic, phonological, and semantic information from more distal parafoveal positions.
A parafoveal priming paradigm combined with a single-character lexical decision task and eye-tracking was employed in the present study to investigate readers’ parafoveal processing ability independently of sentence context and plausibility. Across three experiments, we examined whether Chinese readers could extract orthographic, phonological, and semantic information from a more distal parafoveal position (i.e., character at the N + 3 position). By presenting stimuli outside of sentence context, the parafoveal priming paradigm provides a relatively “pure” measure of parafoveal processing, laying the groundwork for understanding the mechanisms underlying preview effects in natural reading.
The position of preview characters was carefully controlled in the present study based on the objectives and methodological considerations outlined above. To ensure that parafoveal preview fell within the perceptual span, the preview character was presented at the position corresponding to the third character to the right of the fixation in a sentence; i.e., at the N + 3 position. Specifically, the distance from the center of fixation to the left edge of the preview character was set to span precisely two and a half characters. In eye-tracking studies of Chinese reading, each character typically subtends about 1° of the visual angle (
Chang et al., 2024;
Zhang et al., 2023). Each preview character was constrained to occupy approximately 1° of the visual angle to ensure precise positioning, resulting in 2° of the visual angle between the left edge of the preview character and the right edge of the target word.
Given that the preview duration is a critical factor influencing parafoveal processing (
Hohenstein et al., 2010;
J. Pan et al., 2020), three exposure durations for preview characters were employed in the present study. First, since parafoveal information extraction can begin as early as 60 ms after stimulus onset (
Rayner et al., 2006), 60 ms was selected as the shortest preview duration. Second, considering that saccade latency is approximately 150 ms (
Rayner, 1998), the longest preview duration was set to 145 ms to ensure that previews occurred prior to saccade initiation. An intermediate duration of 100 ms was also included to further examine the time course of preview processing.