Optimal landing position in reading isolated words and continuous text

During isolated-word reading, within-word eye-movement tactics (i.e., whether the eye makes one or more fixations on the word) depend strongly on the eye's first fixation position in the word; there exists an optimal landing position where the probability of having to refixate the word is much smaller than when the eye first fixates other parts of the word. The present experiment was designed to test whether the optimal landing position effect still exists during text reading, and to compare the nature and strength of the effect with the effect found for isolated words. The results confirmed the existence of an optimal landing position in both reading conditions, but the effect for words in texts was weaker than it was for isolated words, probably because of the presence of factors such as reading rhythm and linguistic context. However, the effect still existed in text reading; within-word tactics during text reading are dependent on the eye's initial landing position in words. Moreover, individual fixation durations were dependent on within-word tactics. Thus, the initial landing position in words must be taken into account if one wishes to understand eye-movement behavior during text reading. Further results concerned the effects of word length and word frequency in both reading conditions.     

Linguistic and nonlinguistic influences on the eyes' landing positions during reading

Two eye tracking experiments show that, for near launch sites, the eyes land nearer to the beginning of words with orthographically irregular than with regular initial letter sequences. In addition, the characteristics of words, at least at the level of orthography, influence the direction and length of within-word saccades. Importantly, these effects hold both for lower case and for visually less distinctive upper case text. Furthermore, contrary to previous evidence (Tinker & Paterson, 1939), there is little effect of type case on reading times. Additional analyses of oculomotor behaviour suggest that there is an inverted optimal viewing position for single fixation durations on words. Both the supplementary analyses and the effects of orthography on fixation positions are relevant to current models of eye movements in reading.     

Linguistic and nonlinguistic influences on the eyes' landing positions during reading

Two eye tracking experiments show that, for near launch sites, the eyes land nearer to the beginning of words with orthographically irregular than with regular initial letter sequences. In addition, the characteristics of words, at least at the level of orthography, influence the direction and length of within-word saccades. Importantly, these effects hold both for lower case and for visually less distinctive upper case text. Furthermore, contrary to previous evidence (Tinker & Paterson, 1939), there is little effect of type case on reading times. Additional analyses of oculomotor behaviour suggest that there is an inverted optimal viewing position for single fixation durations on words. Both the supplementary analyses and the effects of orthography on fixation positions are relevant to current models of eye movements in reading.     

阅读过程中的词跳读及其产生的认知机制

在阅读过程中,读者并不会注视每一个词,而是不断地跳过很多词。在英文阅读中至少有30%的词被跳读,在中文阅读中近50%的字词被跳读。那么被跳读的字词是否得到加工,何时得到加工,是当前阅读过程中眼动控制模型关心的基本问题：具体包括（1）词跳读是基于副中央凹处词汇的完全识别还是部分识别后发生;（2）中央凹加工负荷是否影响对下一个词的跳读;（3）副中央凹和中央凹加工效率与词跳读的关系是什么;（4）较低水平的视觉信息（如词长、复杂性）和较高水平的语言信息（如词频、预测性）如何交互作用决定一个词的跳读。文章对上述问题进行系统分析,最后结合中文阅读中书写系统的特点,对未来中文阅读中词跳读研究进行了展望。     

词频、可预测性及合理性对目标词首次注视位置的影响

采用三项实验分别考察了目标词的词频、可预测性和合理性对读者眼动模式的影响。结果显示:(1)词频、可预测性和合理性对目标词语的凝视时间和总注视时间都有显著影响,但在首次注视时间上主效应不显著;(2)词频和可预测性不影响目标词的跳读率和再注视概率,而合理性对目标词的再注视概率产生显著的影响;(3)远注视点眼跳倾向于将首次注视位置着落于目标词的开端部位,而近注视点眼跳倾向于将首次注视着落于目标词的中央部位;词频、可预测性和合理性均不影响首次注视位置。     

Eye movements when reading: The importance of the word to the left of fixation

In reading, it is well established that word processing can begin in the parafovea while the eyes are fixating the previous word. However, much less is known about the processing of information to the left of fixation. In two experiments, this issue was explored by combining a gaze-contingent display procedure preventing parafoveal preview and a letter detection task. All words were displayed as a series of xs until the reader fixated them, thereby preventing forward parafoveal processing, yet enabling backward parafoveal or postview processing. Results from both experiments revealed that readers were able to detect a target letter embedded in a word that was skipped. In those cases, the letter could only have been identified in postview (to the left of fixation), and detection rate decreased as the distance between the target letter and the eyes' landing position increased. Most importantly, for those skipped words, the typical missing-letter effect was observed with more omissions for target letters embedded in function than in content words. This can be taken as evidence that readers can extract basic prelexical information, such as the presence of a letter, in the parafoveal area to the left of fixation. Implications of these results are discussed in relation to models of eye movement control in reading and also in relation to models of the missing-letter effect.     

Reading performance in middle-aged adults with declines in accommodation

The present study investigated the effects of presbyopia on the reading ability of middle-aged adults in a Japanese reading context, using the rapid serial visual presentation paradigm. Japanese words, each consisting of three characters, were sequentially presented at the same location on a display screen. Participants were instructed to read the words aloud as accurately as possible, irrespective of their order within the sequence. Experiment 1 showed that the reading performance for the presbyopes was far worse for the near-viewing (35?cm) than for the far-viewing (70?cm) conditions when the words were presented at 0.4° in character size. Experiment 2 investigated in detail the effect of luminance contrast on reading at a viewing distance of 35?cm. The minimums of the exposure durations within which the participants could read the words above 89.9?% correct (minimum exposure duration) were 498?ms/word for the presbyopes and 134?ms/word for the nonpresbyopes, both of which values were obtained at 100?% contrast. The critical contrast??that is, the contrast that doubled the minimum exposure duration that had been obtained at 100?% contrast??was considerably higher for the presbyopes (39.2?%) than for the nonpresbyopes (16.4?%). However, the reading performance for the presbyopes was improved more than threefold when the contrast was increased to 100?% in both experiments. Thus, our results provide psychophysical evidence for the dependency of presbyopes?? reading on viewing distance and luminance contrast.     

中文阅读中词汇加工的年老化:眼动证据

本研究探讨年老化影响中文阅读中词汇加工过程的特点,包含两项实验。实验一探讨老年与青年读者在词频效应上的差异,实验二探讨老年与青年读者在语境预测性效应上的差异。结果发现：（1）相对于青年读者,老年读者注视目标词汇的时间较长、再注视回视较多、跳读较少;（2）在首次注视时间、凝视时间和眼跳参数上,年龄组别与词频之间交互作用不显著,但对目标词汇的总注视时间上,年龄组别与词频之间交互作用显著;（3）在所有注视时间指标和回视概率上,均发现年龄组别与语境预测性影响之间交互作用显著。结论：中文老年读者阅读时的词汇加工效率低于青年人;中文阅读中眼跳策略与词汇加工的年老化模式有语言特殊性特点。     

汉语阅读过程中词切分的位置：一项基于眼动随动显示技术的研究

采用眼动随动显示技术, 通过分析动态协助或干扰词切分对阅读过程的影响, 考察汉语阅读过程中词切分的位置与数量。包括两项实验：实验一通过改变注视点附近词语的颜色来促进词汇的加工进程, 发现协助词n+1切分可改变被试的眼动模式, 说明至少加工词n+1可导致词切分效果; 实验二以类似方法干扰相应的词汇加工进程, 发现在某些实验条件下被试的眼动模式朝相反方向变化, 表明实验一结果并非由外源注意转移引起。综合分析两个实验中各种条件下首次注视概率分布、再注视时的首次注视时间和单一注视时间的差异, 得出以下结论：在汉语阅读中存在两种词切分现象, 一种由加工词n+1引起, 另一种由加工词n引起。     

Orthographic familiarity influences initial eye fixation positions in reading

An important issue in the understanding of eye movements in reading is what kind of nonfoveal information can influence where we move our eyes. In Experiment 1, first fixation landing positions were nearer the beginning of misspelled words. Experiment 2 showed that the informativeness of word beginnings does not influence where words are first fixated. In both experiments, refixations were more likely to be to the left of the initial fixation position if the words were misspelled. Also, there was no influence of spelling on prior fixation durations or refixation probabilities, that is, there was no evidence for parafoveal‐on‐foveal effects. The results show that the orthographic familiarity, but not informativeness, of word initial letter sequences influences where words are first fixated.     

Reading strategy modulates parafoveal-on-foveal effects in sentence reading

Task demands and individual differences have been linked reliably to word skipping during reading. Such differences in fixation probability may imply a selection effect for multivariate analyses of eye-movement corpora if selection effects correlate with word properties of skipped words. For example, with fewer fixations on short and highly frequent words the power to detect parafoveal-on-foveal effects is reduced. We demonstrate that increasing the fixation probability on function words with a manipulation of the expected difficulty and frequency of questions reduces an age difference in skipping probability (i.e., old adults become comparable to young adults) and helps to uncover significant parafoveal-on-foveal effects in this group of old adults. We discuss implications for the comparison of results of eye-movement research based on multivariate analysis of corpus data with those from display-contingent manipulations of target words.     

Not fixating at the line of text comes at a cost

Previous research on eye guidance in reading has investigated systematic tendencies with respect to horizontal fixation locations on letters within words and the relationship between fixation location in a word and the duration of the fixation. The present study investigates where readers place their eyes vertically on the line of text and how vertical fixation location is related to fixation duration. Analyses were based on a large corpus of eye movement recordings from single-sentence reading. The vertical preferred viewing location was found to be within the vertical extent of the font, but fixations beyond the vertical boundaries of the text also frequently occurred. Analyzing fixation duration as a function of vertical fixation location revealed a vertical optimal viewing position (vOVP) effect: Fixations were shortest when placed optimally on the line of text, and fixation duration gradually increased for fixations that fell above or below the line of text. The vOVP effect can be explained by the limits of visual resolution along the vertical meridian. It is concluded that vertical and horizontal landing positions in single-sentence reading are associated with differences in fixation durations in opposite ways.     

A perceptual-economy account for the inverted-optimal viewing position effect

In reading, fixation durations are longer when the eyes fall near the center of words than when fixation occurs toward the words' ends-the inverted-optimal viewing position (I-OVP) effect. This study assessed whether the I-OVP effect was based on the fixation position in the word or the fixation position in the visual stimulus. In Experiments 1-3, words were presented at variable locations within longer strings of symbols. On trials with short fixation durations, there were effects of fixation position in the string. When long fixations were made, there were effects of fixation position in the word. In Experiment 4, an I-OVP effect was found for meaningless number strings, and its strength depended on the task's processing demands. The findings show that (a) the I-OVP effect is unrelated to orthographic informativeness and (b) the eyes are not constrained to spend more time at the center of visual stimuli. These results support a perceptual-economy account: Fixations are held longer when the eyes are estimated to be at locations in words/stimuli in which greater amounts of information are anticipated. Implications for eye movements in reading are discussed.     

Fixation durations before word skipping in reading

We resolve a controversy about reading fixations before word-skipping saccades which were reported as longer or shorter than control fixations in earlier studies. Our statistics are based on resampling of matched sets of fixations before skipped and nonskipped words, drawn from a database of 121,321 single fixations contributed by 230 readers of the Potsdam sentence corpus. Matched fixations originated from single-fixation forward-reading patterns and were equated for their positions within words. Fixations before skipped words were shorter before short or high-frequency words and longer before long or low-frequency words in comparison with control fixations. Reasons for inconsistencies in past research and implications for computational models are discussed.     

汉字笔画数对注视位置效应的影响

采用EyeLink 2000眼动仪,选取四种不同类型的双字词（首字和尾字均为多笔画汉字;首字为多笔画汉字,尾字为少笔画汉字;首字为少笔画汉字,尾字为多笔画汉字;首字和尾字均为少笔画汉字）,要求被试阅读包含有目标词的句子,以探讨汉字笔画数对注视位置效应的影响。结果发现,单次注视条件下,读者往往将首次注视定位于词的中心位置,多次注视时首次注视往往落在词的开头部分;但是当首字为多笔画汉字时,相较于首字为少笔画汉字,读者对目标词的首次注视更多地落在词的首字上。首字和尾字笔画数共同影响读者对目标词的再注视概率。研究结果支持“战略-战术”模型。     

Within-word serial order control: Adjacent mora exchange and serial position effects in repeated single-word production

An essential function of language processing is serial order control. Computational models of serial ordering and empirical data suggest that plan representations for ordered output of sound are governed by principles related to similarity. Among these principles, the temporal distance and edge principles at a within-word level have not been empirically demonstrated separately from other principles. Specifically, the temporal distance principle assumes that phonemes that are in the same word and thus temporally close are represented similarly. This principle would manifest as phoneme movement errors within the same word. However, such errors are rarely observed in English, likely reflecting stronger effects of syllabic constraints (i.e., phonemes in different positions within the syllable are distinctly represented). The edge principle assumes that the edges of a sequence are represented distinctly from other elements/positions. This principle has been repeatedly observed as a serial position effect in the context of phonological short-term memory. However, it has not been demonstrated in single-word production. This study provides direct evidence for the two abovementioned principles by using a speech-error induction technique to show the exchange of adjacent morae and serial position effects in Japanese four-mora words. Participants repeatedly produced a target word or nonword, immediately after hearing an aurally presented distractor word. The phonologically similar distractor words, which were created by exchanging adjacent morae in the target, induced adjacent-mora-exchange errors, demonstrating the within-word temporal distance principle. There was also a serial position effect in error rates, such that errors were mostly induced at the middle positions within a word. The results provide empirical evidence for the temporal distance and edge principles in within-word serial order control.     

What do letter migration errors reveal about letter position coding in visual word recognition?

Dividing attention across multiple words occasionally results in misidentifications whereby letters apparently migrate between words. Previous studies have found that letter migrations preserve within-word letter position, which has been interpreted as support for position-specific letter coding. To investigate this issue, the authors used word pairs like STEP and SOAP, in which a letter in 1 word could migrate to an adjacent letter in another word to form an illusory word (STOP). Three experiments show that both same-position and adjacent-position letter migrations can occur, as well as migrations that cross 2 letter positions. These results argue against position-specific letter coding schemes used in many computational models of reading, and they provide support for coding schemes based on relative rather than absolute letter position.     

Length,frequency, and predictability effects of words on eye movements in reading

We tested the effects of word length, frequency, and predictability on inspection durations (first fixation, single fixation, gaze duration, and reading time) and inspection probabilities during first‐pass reading (skipped, once, twice) for a corpus of 144 German sentences (1138 words) and a subset of 144 target words uncorrelated in length and frequency, read by 33 young and 32 older adults. For corpus words, length and frequency were reliably related to inspection durations and probabilities, predictability only to inspection probabilities. For first‐pass reading of target words all three effects were reliable for inspection durations and probabilities. Low predictability was strongly related to second‐pass reading. Older adults read slower than young adults and had a higher frequency of regressive movements. The data are to serve as a benchmark for computational models of eye movement control in reading.     

On the role of refixations in letter strings: the influence of oculomotor factors

Recent studies of reading and word recognition have shown that eye-movement behavior depends strongly on the position in the word that the eye first fixates; the probability of refixating in a word is lowest with the eye near the middle of the word, and it increases as the eye fixates to either side. It has generally been assumed that the cause for this optimal landing position phenomenon lies in the very strong drop-off of visual acuity even within the fovea; refixation should be more likely when the eye starts from a noncentral position, because here less information can be extracted during one fixation. It may, however, be the case that the phenomenon is caused not by acuity drop-off, but by differences in within-word oculomotor scanning tactics as a function of the position that the eye initially fixates. To test this, in the present experiment we kept visual information constant while we varied the initial fixation position. We used homogeneous strings of letters of different length. One letter in each string was different from the rest (e.g., kkkkkok), and this was the letter that the subject initially fixated. This target letter had to be identified before saccading to a comparison string. The position of the target letter in the string was varied from trial to trial. If, owing to acuity limitations, refixations reflect insufficient information extraction, then, because the target letter is always directly fixated, the pattern of refixations in this condition should be independent of the first fixation position. However, the obtained refixation probability showed a strong dependence on the position of first fixation. The number of refixations was independent of the absolute length of the letter strings, but it seemed to be influenced by the proportion of the string over which the eye had to pass. The larger this proportion, the higher the probability of refixation. The results suggest that to a certain extent refixations in letter strings (or words) reflect properties of the oculomotor system rather than visual information extraction.     

The combined effect of context and case alternation on migration

Summary Previous studies have demonstrated the occurrence of perceptual interactions when words are presented simultaneously in a visual display. The interactions, or migrations, consist of the formation of new words from letters in the display. Contextual information can increase the probability of migration. A difference in visual form between the words does not affect the occurrence of migrations.Two experiments are reported that manipulate context and visual form. Both between-word case alternation and within-word case alternation were used. Neither of these two forms of case alternation affected the occurrence of migrations or the interaction of context with migration, although within-word case alternation reduced the accuracy of word identification.