Eye Movement Control In Reading For Children And Adults: The Role Of Word Boundaries

When do our eyes move, and where do they move next during reading? Are eye movements behavior guided by moment-to-moment cognitive processes or are they controlled by low-level oculomotor strategies? Recently, the study of eye movement control in reading is a flourishing field of research. Given that the two issues are so fundamental to reading behavior, researchers have been endeavoring to develop different types of computational models in terms how well they explain when and where readers fixate during reading. However, they are still under debate to these issues. Based on the previous studies, the role of low-level word boundary information on word identification and eye movement control during Chinese reading was investigated.Three studies including six experiments were carried out. In Study 1 and 2, the temporal aspect of eye-movement behavior, the "when" decision, was the focus analysis, to examine the role of word boundary information on word identification and sentence reading performance. In Study 3, the spatial aspect of eye-movement behavior, the "where" decision, was the focus analysis, to examine the role of word boundary information in guiding eye movement behavior. The detailed contents and main findings were shown as follows.In Study 1, two experiments were included, and the skilled adults were selected as the participants. In Experiment 1, sentences were constructed with four types of spacing information:normal unspaced text, text with spaces between words, text with spaces between characters that yielded nonwords, and text with spaces between every character. Adults'eye movements were monitored as they read text that did or did not demark word boundary information. In Experiment 2, highlighting was used to create analogous conditions to Experiment 1 but controlling the spatial extent of sentences:normal Chinese text, text with highlighting used to mark words, text with highlighting that yielded nonwords, and text with highlighting to mark each character, to replicate the findings from experiment 1.In Study 2, three experiments were included, and the third graders were selected as the participants. This study aimed at exploring the role of word boundary information in beginners' reading, and further examining whether the spacing effect obtained from Study 1 was due to the reading skills and the familiarity with the text presentation for readers. In Experiment 3 and 4, the presentation condition was identical to Experiment 1 and 2, separately. That is, spaces were used in Experiment 3, and highlighting was used in Experiment 4, to demarcate the word boundary. In Experiment 5, the reading skills of third graders were manipulated to examine whether the spacing effect was mediated by reading skills.In Study 3, inter-word spacing and landing position effect during spaced and unspaced text reading in children and adults were investigated. The presentation condition (normal unspaced and word spaced text) and participant group (children and adults) were manipulated. The eye movement measures reflecting the spatial aspect like initial landing position in different fixation cases, refixation probability and location as a function of initial landing position, etc, were analyzed. The landing position effect was directly compared between children and adults when reading spaced and unspaced Chinese text, and to examine the influence of word boundary information in guiding eye movement behaviour.To summarize the findings of the three studies, the conclusion was made as follows.(1) Demarcating word boundaries either through the use of spaces or highlighting during Chinese reading did not interfere with reading. By contrast, nonword spacing and a space (or using highlighting) between every character decreased reading speed.(2) There were basic developmental differences in eye movement behavior between children and adults. Compared to children, adults adopted much more effective and flexible strategy to identify a word and to target a position of the word. These differences were due to the reading proficiency and the oculomotor control skills of readers.(3) Sentences with word spaced format were as easy to read as the unspaced text for both children and adults. Furthermore, interword spaces demonstrated an advantage for its clear word segmentation during the early lexical processing. It facilitated access to the word and the early word identification, and this effect occurred to a very similar degree for both children and adults.(4) The role of word boundary information in guiding eye movement behavior indicated an interesting dissociation in different fixation cases. When a word was read with a single fixation, children and adults made their saccades perfectly to a word center (optimal viewing position) whatever the text was spaced or unspaced. When a multiple fixations was made on a word, the initial landing position was further into a word when reading word spaced text compared to normal unspaced text. Whereas for the multiple fixation cases, children and adults tended to fixate a word beginning, and then make an intraword refixation.(5) The decision about where to move the eyes during Chinese reading is word based, that is, a word object is selected as the next saccade target. v...