Effects of word spacing on reading Chinese text from a video display terminal

Segmentation of Spoken Overlapping Ambiguity Strings in Chinese: An Eye-Tracking Study

PURPOSE

Using the printed-word paradigm with eye tracking, this study conducted three experiments to examine (a) how multiple words in spoken overlapping ambiguity strings (OASs) are activated, (b) how word frequency influences the word segmentation of spoken OASs, and (c) whether the multiple words in spoken OASs are activated competitively or independently.

METHOD

In this study, participants listened to a four-character spoken OAS (ABCD) and were presented with a visual display composed of a semantic associate of the "middle word" (BC; Experiments 1 and 2) or the "left word" (AB; Experiment 3) and two distractors. In Experiment 1, the word frequency of the middle words was manipulated to be higher than that of the neighbor words. In Experiment 2, the word frequency of the middle words was manipulated to be either higher or lower than that of the neighbor words. In Experiment 3, participants listened to either spoken OASs (ABCD) or spoken unambiguous strings (ABEF).

RESULTS

In Experiment 1, we observed a significant semantic competition effect; that is, more fixations fell on the semantic competitors than on distractors, suggesting that the semantic information of the middle words in the spoken OASs was activated. In Experiment 2, the semantic competition effect was only observed in the high-frequency condition and was absent in the low-frequency condition. In Experiment 3, the results showed significant semantic competition effects for the left words under both conditions, and the observed effect was similar between the ambiguity condition and the control condition.

CONCLUSIONS

These findings show that multiple words in spoken OASs are all activated and the activation level is modulated by word frequency. In addition, multiple words in the spoken OASs may be processed independently during spoken comprehension.

Rational Sentence Interpretation in Mandarin Chinese

Previous work has shown that English native speakers interpret sentences as predicted by a noisy-channel model: They integrate both the real-world plausibility of the meaning-the prior-and the likelihood that the intended sentence may be corrupted into the perceived sentence. In this study, we test the noisy-channel model in Mandarin Chinese, a language taxonomically different from English. We present native Mandarin speakers sentences in a written modality (Experiment 1) and an auditory modality (Experiment 2) in three pairs of syntactic alternations. The critical materials are literally implausible but require differing numbers and types of edits in order to form more plausible sentences. Each sentence is followed by a comprehension question that allows us to infer whether the speakers interpreted the item literally, or made an inference toward a more likely meaning. Similar to previous research on related English constructions, Mandarin participants made the most inferences for implausible materials that could be inferred as plausible by deleting a single morpheme or inserting a single morpheme. Participants were less likely to infer a plausible meaning for materials that could be inferred as plausible by making an exchange across a preposition. And participants were least likely to infer a plausible meaning for materials that could be inferred as plausible by making an exchange across a main verb. Moreover, we found more inferences in written materials than spoken materials, possibly a result of a lack of word boundaries in written Chinese. Overall, the fact that the results were so similar to those found in related constructions in English suggests that the noisy-channel proposal is robust.

The database of eye-movement measures on words in Chinese reading

Eye movements are one of the most fundamental behaviors during reading. A growing number of Chinese reading studies have used eye-tracking techniques in the last two decades. The accumulated data provide a rich resource that can reflect the complex cognitive mechanisms underlying Chinese reading. This article reports a database of eye-movement measures of words during Chinese sentence reading. The database contains nine eye-movement measures of 8,551 Chinese words obtained from 1,718 participants across 57 Chinese sentence reading experiments. All data were collected in the same experimental environment and from homogenous participants, using the same protocols and parameters. This database enables researchers to test their theoretical or computational hypotheses concerning Chinese reading efficiently using a large number of words. The database can also indicate the processing difficulty of Chinese words during text reading, thus providing a way to control or manipulate the difficulty level of Chinese texts.

Effects of Spacing on Sentence Reading in Chinese

Given that Chinese writing conventions lack inter-word spacing, understanding whether and how readers of Chinese segment regular unspaced Chinese writing into words is an important question for theories of reading. This study examined the processing outcomes of introducing spaces to written Chinese sentences in varying positions based on native speaker consensus. The measure of consensus for every character transition in our stimuli sentences was the percent of raters who placed a word boundary in that position. The eye movements of native readers of Chinese were recorded while they silently read original unspaced sentences and their experimentally manipulated counterparts for comprehension. We introduced two types of spaced sentences: one with spaces inserted at every probable word boundary (heavily spaced), and another with spaces placed only at highly probable word boundaries (lightly spaced). Linear mixed-effects regression models showed that heavily spaced sentences took identical time to read as unspaced ones despite the shortened fixation times on individual words (Experiment 1). On the other hand, reading times for lightly spaced sentences and words were shorter than those for unspaced ones (Experiment 2). Thus, spaces proved to be advantageous but only when introduced at highly probable word boundaries. We discuss methodological and theoretical implications of these findings.

Manipulating Interword and Interletter Spacing in Cursive Script: An Eye Movements Investigation of Reading Persian

Persian is an Indo-Iranian language that features a derivation of Arabic cursive script, where most letters within words are connectable to adjacent letters with ligatures. Two experiments are reported where the properties of Persian script were utilized to investigate the effects of reducing interword spacing and increasing the interletter distance (ligature) within a word. Experiment 1 revealed that decreasing interword spacing while extending interletter ligature by the same amount was detrimental to reading speed. Experiment 2 largely replicated these findings. The experiments show that providing the readers with inaccurate word boundary information is detrimental to reading rate. This was achieved by reducing the interword space that follows letters that do not connect to the next letter in Experiment 1, and replacing the interword space with ligature that connected the words in Experiment 2. In both experiments, readers were able to comprehend the text read, despite the considerable costs to reading rates in the experimental conditions.

Morphosemantic activation of opaque Chinese words in sentence comprehension

Two cross-modal priming experiments were conducted to investigate morphological processing in Chinese spoken word recognition during sentence comprehension. Participants heard sentences that contained opaque prime words and performed lexical decisions on visual targets that were related to second morpheme meanings of opaque words or whole-word meanings. The targets were presented at the auditory onset of the second morphemes or the subsequent syllables after the opaque primes to examine the time course of effects. In a neutral sentence context (Experiment 1), opaque word morpheme meanings produced morphological priming on target word recognition, which preceded lexical priming. When context biased toward whole opaque words (Experiment 2), morphological priming disappeared, while the effect of lexical meanings remained significant and emerged earlier than the effect of lexical meanings in the neutral context. These findings suggest that morphemes play a role in Chinese spoken word recognition, but their effects depend on the prior context during sentence comprehension.

Word segmentation by alternating colors facilitates eye guidance in Chinese reading

During sentence reading, low spatial frequency information afforded by spaces between words is the primary factor for eye guidance in spaced writing systems, whereas saccade generation for unspaced writing systems is less clear and under debate. In the present study, we investigated whether word-boundary information, provided by alternating colors (consistent or inconsistent with word-boundary information) influences saccade-target selection in Chinese. In Experiment 1, as compared to a baseline (i.e., uniform color) condition, word segmentation with alternating color shifted fixation location towards the center of words. In contrast, incorrect word segmentation shifted fixation location towards the beginning of words. In Experiment 2, we used a gaze-contingent paradigm to restrict the color manipulation only to the upcoming parafoveal words and replicated the results, including fixation location effects, as observed in Experiment 1. These results indicate that Chinese readers are capable of making use of parafoveal word-boundary knowledge for saccade generation, even if such information is unfamiliar to them. The present study provides novel support for the hypothesis that word segmentation is involved in the decision about where to fixate next during Chinese reading.

A Developmental Study of Chinese Children's Word and Character Reading

To investigate the relationship between Chinese children's character and word reading, 62 third and 50 fifth grade children in Hong Kong were asked to read single characters and words that were comprised of these characters. Results showed that words helped children to recognize characters for both grades of children. Compared to older children, younger children's character reading was more likely to rely on the word that the character appeared in as a component; younger children made more errors in confusing the correct character with words related to it. Younger children's greater rate of meaning-related errors also underscored the role of the word in their character learning. This study confirmed the important role of words in children's character learning, and provided evidence for a developmental pattern of character and word reading in Chinese.

To space or not space? Interword spacing effects on Chinese children's reading materials

This study investigated different Chinese on-screen text layouts to see if they improved the reading speed and comprehension of Taiwanese children. A number of different experimental treatments were used. These were: interword spacing (unspaced, semi-spaced and fully-spaced), text difficulty (easy and difficult) and text direction (vertical and horizontal). The experiment involved 84 children aged between 10 and 11 years old. In the experiment the children were asked to read articles. The time they took to read these articles was recorded. The children also partook in comprehension tests to determine how much they had understood about the articles they had read. The results showed that horizontal text was read more quickly than vertical text and was better comprehended. The results also showed that fully-spaced difficult text was read more quickly than semi-spaced difficult text, and unspaced difficult text was also better comprehended. Practitioner Summary: This experiment was conducted to explore the affects of interword spacing, text direction and text difficulty on the reading speeds and comprehension of on-screen traditional Chinese characters by Taiwanese children. It found that fully-spaced, horizontal text was the quickest and most comprehendible to read, regardless of text difficulty.

Word segmentation of overlapping ambiguous strings during Chinese reading

In 3 experiments, we tested 3 possible mechanisms for segmenting overlapping ambiguous strings in Chinese reading. The first 2 characters and the last 2 characters in a 3-character ambiguous string could both constitute a word in the reported studies. The left-priority hypothesis assumes that the word on the left has an advantage in the competition and the other word cannot be processed until the word on the left is recognized. The independent processing hypothesis assumes that words in different positions are processed simultaneously and independently, and the word segmentation ambiguity cannot be settled without the help of sentence context. The competition hypothesis assumes that all of the words compete for a single winner. The results support a competition account that the characters in the perceptual span activate all of the words they can constitute, and any word can win the competition if its activation is high enough.

Inserting spaces before and after words affects word processing differently in Chinese: Evidence from eye movements

Unlike in English, there are no spaces between printed words in Chinese. In this study, we explored how inserting a space before or after a word affects the processing of that word in Chinese reading. Native Chinese readers' eye movements were monitored as they read sentences with different presentation conditions. The results show that inserting a space after a word facilitates its processing, but inserting a space before a word does not show this effect and inhibits the processing of that word in some cases. Our results are consistent with the prediction of a word segmentation and recognition model in Chinese Li et al., 2009, Cognit. Psychol., 58, 525. Additionally, we found that a space guides the initial landing position on the word: the initial landing position was further away from the space that inserted into the text, whether it was before or after a word.

Rapid Serial Visual Presentation Display on a Small Screen: Reading Chinese While Walking

This study examined the effects of presentation unit (word-byword or single line) and presentation duration [171, 213, 240, and 308 msec, per character (msec./C)] on the comprehension of Chinese rapid serial visual presentation (RSVP) displays read from the small screen of a mobile phone in three different contexts (seated, walking on a treadmill, and walking through an outdoor course). 30 native Chinese readers ages 19 to 26 were recruited as participants. Scores on reading comprehension showed that presentation unit and presentation duration significantly affected reading comprehension, and interactions between factors were also significant. When the presentation unit was word-by-word, no significant difference in reading comprehension was observed under different presentation durations. However, when the presentation unit was a single line, reading comprehension deteriorated with the shortest presentation duration of 171 msec./C. With regard to context, participants had a higher mean reading comprehension score in the seated context than in walking contexts, but the difference was not significant.

Flexible saccade-target selection in Chinese reading

As Chinese is written without orthographical word boundaries (i.e., spaces), it is unclear whether saccade targets are selected on the basis of characters or words and whether saccades are aimed at the beginning or the centre of words. Here, we report an experiment where 30 Chinese readers read 150 sentences while their eye movements were monitored. They exhibited a strong tendency to fixate at the word centre in single-fixation cases and at the word beginning in multiple-fixation cases. Different from spaced alphabetic script, initial fixations falling at the end of words were no more likely to be followed by a refixation than initial fixations at word centre. Further, single fixations were shorter than first fixations in two-fixation cases, which is opposite to what is found in Roman script. We propose that Chinese readers dynamically select the beginning or centre of words as saccade targets depending on failure or success with segmentation of parafoveal word boundaries.

Learning and context of use for small-screen leading displays on visual performance in a Chinese sample

Leading displays represent mechanisms for exhibiting temporal instead of spatial information to overcome the limited display space of mobile devices. Prior studies focused only on information presented but disregarded the influence of context of use and learnability. In this study, 12 Chinese-speaking college students were presented a small-screen mobile device that simultaneously showed 100 Chinese characters and a 30-character leading display. Analyzed were presentation rate (250, 350, and 450 characters per minute), presentation mode (character-by-character or word-by-word), and learning (5 practice sessions) by instructing the subjects to perform a static information search task to identify the location of target characters on the screen and through an evaluation of reading comprehension for the text presented in the leading display. There was no significant change in performance over the 5 days of practice, but the rate of presentation and word-by-word presentation significantly affected reading comprehension. Results indicated that none of the leading-display factors distracted subjects from the static information-search task, but they were influenced by comprehension of the leading-display content.

Reading spaced and unspaced Chinese text: evidence from eye movements

Native Chinese readers' eye movements were monitored as they read text that did or did not demark word boundary information. In Experiment 1, sentences had 4 types of spacing: normal unspaced text, text with spaces between words, text with spaces between characters that yielded nonwords, and finally text with spaces between every character. The authors investigated whether the introduction of spaces into unspaced Chinese text facilitates reading and whether the word or, alternatively, the character is a unit of information that is of primary importance in Chinese reading. Global and local measures indicated that sentences with unfamiliar word spaced format were as easy to read as visually familiar unspaced text. Nonword spacing and a space between every character produced longer reading times. In Experiment 2, highlighting was used to create analogous conditions: normal Chinese text, highlighting that marked words, highlighting that yielded nonwords, and highlighting that marked each character. The data from both experiments clearly indicated that words, and not individual characters, are the unit of primary importance in Chinese reading.

Eye movements and the identification of spatially ambiguous words during chinese sentence reading

Readers of Chinese must generally determine word units in the absence of visually distinct inter-word spaces. In the present study, we examined how a sequence of Chinese characters is parsed into words under these conditions. Eye movements were monitored while participants read sentences with a critical four-character (C1234) sequence. Three partially overlapping character groupings formed legal words in the ambiguous condition (C12, C23, and C34), two of which corresponded to context-consistent words (C12 and C34). Two nonoverlapping groupings corresponded to legal words in the control conditions (C12 and C34). In two experiments, readers spent more time viewing the critical character sequence and its two center characters (C23) in the ambiguous condition. These results argue against the strictly serial assignment of characters to words during the reading of Chinese text.

Dynamic Chinese text on a single-line display: effects of presentation mode

There are many technologies with which users must read text from small-screen electronic devices. So, understanding the constraints and optimization of humans' use of these devices is important. In the present study, the optimal ways to display Chinese text on a single-line display were explored. 64 Chinese-speaking Taiwanese undergraduates participated in a 4x2 mixed design in which the presentation mode was a between-subjects factor and the text difficulty was a within-subjects factor. Four presentation modes in which two presentation formats, i.e., leading and rapid serial visual presentation, combined with two text layouts, i.e., convention and Interword spacing, were investigated. Chinese texts of High Difficulty and Low Difficulty were compared. The results showed that the leading format with Interword spacing resulted in greater reading efficiency and faster preferred reading speed than other presentation modes. Although the reading efficiency and preferred reading speed for Low Difficulty materials were significantly greater than for High Difficulty materials, the interaction between the presentation mode and text difficulty was not significant. The applications for presenting moving Chinese text on a single-line display are briefly discussed.