Eye movements and variations in reading time

Summary Passages of prose were constructed which obeyed a stylistic convention referred to as dovetailing. For a given pair of sentences the final position of the first, and the initial position of the second, had the same referent. It was shown that critical dovetailed lines of text were read more rapidly than lines containing the same information, but lacking sequential structure. Degrading text by obscuring all interword spaces removed this reading time advantage. Analysis of subjects' eye movements during reading suggested that reading facilitation, induced by dovetailing, may result, not only from higher-order structural properties of text, but also from local features (particularly word-length information and associative relationships between words) known to influence eye movements.     

Eye movements and spatial coding in reading

Summary Two experiments are reported which test the hypothesis that during reading subjects maintain in working memory a record of the spatial location of items and that this code is used to guide reinspections. In the first experiment the premisses of short syllogisms were read, one word at a time, under three presentation conditions: (a) in correct temporal order and in appropriate sequential spatial locations; (b) in correct temporal order but in random spatial locations; (c) in correct temporal order and in a single central location. A measure was taken of the time to respond to possible conclusions of the syllogisms. Solution times were longer in conditions (b) and (c) relative to (a). In the second experiment eye movements were recorded as subjects judged the soundness of auditorily presented conclusions following visual presentation of the premisses of syllogisms. Non-random eye movements took place during the solution phase directed to locations previously occupied by text in the display.     

Eye movements during reading: some current controversies

For many researchers, eye-movement measures have become instrumental in revealing the moment-to-moment activity of the mind during reading. In general, there has been a great deal of consistency across studies within the eye-movement literature, and researchers have discovered and examined many variables involved in the reading process that affect the nature of readers' eye movements. Despite remarkable progress, however, there are still a number of issues to be resolved. In this article, we discuss three controversial issues: (1) the extent to which eye-movement behavior is affected by low-level oculomotor factors versus higher-level cognitive processes; (2) how much information is extracted from the right of fixation; and (3) whether readers process information from more than one word at a time.     

Mindless reading revisited: Eye movements during reading and scanning are different

In an extension of a study by Vitu, O’Regan, Inhoff, and Topolski (1995), we compared global and local characteristics of eye movements during (1) reading, (2) the scanning of transformed text (in which each letter was replaced with a z), and (3) visual search. Additionally, we examined eye behavior with respect to specific target words of high or low frequency. Globally, the reading condition led to shorter fixations, longer saccades, and less frequent skipping of target strings than did scanning transformed text. Locally, the manipulation of word frequency affected fixation durations on the target word during reading, but not during visual search or z-string scanning. There were also more refixations on target words in reading than in scanning. Contrary to Vitu et al.’s (1995) findings, our results show that eye movements are not guided by a global strategy and local tactics, but by immediate processing demands.     

Visual attention in reading: Eye movements reflect cognitive processes

Two hypotheses regarding the nature of fixation durations in reading were discussed. One position suggests that semantic processing lags behind the perceptual input of information. The other position suggests that semantic processing is more rapid and immediate. Eye movement data of skilled readers reading passages of text were analyzed. It was found that the main verb of the sentence received more visual attention than other key grammatical elements within a sentence. On the basis of the overall result pattern, it was argued that eye movements are affected by cognitive processes occurring at the time of the fixations.     

Eye movements and brain electric potentials during reading

The development of theories and computational models of reading requires an understanding of processing constraints, in particular of timelines related to word recognition and oculomotor control. Timelines of word recognition are usually determined with event-related potentials (ERPs) recorded under conditions of serial visual presentation (SVP) of words; timelines of oculomotor control are derived from parameters of eye movements (EMs) during natural reading. We describe two strategies to integrate these approaches. One is to collect ERPs and EMs in separate SVP and natural reading experiments for the same experimental material (but different subjects). The other strategy is to co-register EMs and ERPs during natural reading from the same subjects. Both strategies yield data that allow us to determine how lexical properties influence ERPs (e.g., the N400 component) and EMs (e.g., fixation durations) across neighboring words. We review our recent research on the effects of frequency and predictability of words on both EM and ERP measures with reference to current models of eye-movement control during reading. Results are in support of the proposition that lexical access is distributed across several fixations and across brain-electric potentials measured on neighboring words.     

Eye movements and word skipping during reading revisited

The authors examined word skipping in reading in 2 experiments. In Experiment 1, skipping rates were higher for a preview of a predictable word than for a visually similar nonword, indicating there is full recognition in parafoveal vision. In Experiment 2, foveal load was manipulated by varying the frequency of the word preceding either a 3-letter target word or a misspelled preview. There was again a higher skipping rate for a correct preview and a lower skipping rate when there was a high foveal load, but there was no interaction, and the pattern of effects in fixation times was the same as in the skipping data. Experiment 2 also showed significant skipping of nonwords similar to the target word, indicating skipping based on partial information.     

Eye movements and display change detection during reading

In the boundary change paradigm (Rayner, 1975), when a reader's eyes cross an invisible boundary location, a preview word is replaced by a target word. Readers are generally unaware of such changes due to saccadic suppression. However, some readers detect changes on a few trials and a small percentage of them detect many changes. Two experiments are reported in which we combined eye movement data with signal detection analyses to investigate display change detection. On each trial, readers had to indicate if they saw a display change in addition to reading for meaning. On half the trials the display change occurred during the saccade (immediate condition); on the other half, it was slowed by 15-25 ms (delay condition) to increase the likelihood that a change would be detected. Sentences were presented in an alternating case fashion allowing us to investigate the influence of both letter identity and case. In the immediate condition, change detection was higher when letters changed than when case changed corroborating findings that word processing utilizes abstract (case independent) letter identities. However, in the delay condition (where d' was much higher than the immediate condition), detection was equal for letter and case changes. The results of both experiments indicate that sensitivity to display changes was related to how close the eyes were to the invalid preview on the fixation prior to the display change, as well as the timing of the completion of this change relative to the start of the post-change fixation.     

Eye movements of young and older adults during reading

The eye movements of young and older adults were tracked as they read sentences varying in syntactic complexity. In Experiment 1, cleft object and object relative clause sentences were more difficult to process than cleft subject and subject relative clause sentences; however, older adults made many more regressions, resulting in increased regression path fixation times and total fixation times, than young adults while processing cleft object and object relative clause sentences. In Experiment 2, older adults experienced more difficulty than young adults while reading cleft and relative clause sentences with temporary syntactic ambiguities created by deleting the that complementizers. Regression analyses indicated that readers with smaller working memories need more regressions and longer fixation times to process cleft object and object relative clause sentences. These results suggest that age-associated declines in working memory do affect syntactic processing.     

Eye movements during repeated reading of a text

The facilitation of eye movements was studied in two experiments involving a repeated reading paradigm. A text was read three times. Initial reading was immediately followed by the first repetition; the second repetition took place one week later. Recall task instructions were used to encourage a detailed reading of the text. The data were analysed sentence by sentence from the 'first pass' readings not including returns to earlier test locations. A general facilitation for all eye movement parameters was found. Repetition decreased the summed fixation time, the average fixation duration, the number of progressive fixations, and the number of regressions. Additionally, repetition increased saccade lengths. Experiment 2 further qualified the general facilitory effect. The middle section of the text, being the most dense of information, was devoted the most visual attention by the readers. Moreover, it was also found to produce the largest degree of facilitation due to repetition. This was true with all other eye movement parameters except saccade length and average fixation duration. Average fixation durations were longer in the beginning of a text than in the end. This was true in all the three readings. Similarly, for each reading, highly important sentences received more visual attention than unimportant sentences.     

Eye movements and the perceptual span in silent and oral reading

Previous research has examined parafoveal processing during silent reading, but little is known about the role of these processes in oral reading. Given that masking parafoveal information slows down silent reading, we asked whether a similar effect also occurs in oral reading. To investigate the role of parafoveal processing in silent and oral reading, we manipulated the parafoveal information available to readers by changing the size of a gaze-contingent moving window. Participants read silently and orally in a one-word window and a three-word window condition as we monitored their eye movements. The lack of parafoveal information slowed reading speed in both oral and silent reading. However, the effects of parafoveal information were larger in silent reading than in oral reading, because of different effects of preview information on both when the eyes move and how often. Parafoveal information benefitted silent reading for faster readers more than for slower readers.     

Eye movements and phonological parafoveal preview: effects of reading skill.

Eye movements of skilled and less skilled readers were monitored as they read sentences containing a target word. The boundary paradigm was used such that when their eyes crossed an invisible boundary location, a preview word changed to the target word. The preview could either be identical to the target word (beach as a preview for beach), a homophone of the target word (beech as a preview for beach), an orthographic control (bench as a preview for beach), or an unrelated consonant string (jfzrp as a preview for beach). Consistent with prior research, skilled readers obtained more preview benefit from the homophone preview than from the orthographic preview. The less skilled readers, however, did not show such an effect. The results indicate that less skilled readers do not use phonological codes to integrate information across eye movements. Indeed, the results also indicate that less skilled readers do not show normal preview benefit effects.     

Eye movements,the perceptual span,and reading speed

The perceptual span or region of effective vision during eye fixations in reading was examined as a function of reading speed (fast readers were compared with slow readers), font characteristics (fixed width vs. proportional width), and intraword spacing (normal or reduced). The main findings were that fast readers (reading at about 330 wpm) had a larger perceptual span than did slow readers (reading about 200 wpm) and that the span was not affected by whether or not the text was fixed width or proportional width. In addition, there were interesting font and intraword spacing effects that have important implications for the optimal use of space in a line of text.     

Eye movements in developing readers: A comparison of silent and oral sentence reading

We present sentence reading data from a large-scale study with children (N = 632), focusing on three key research questions. (1) What are the trajectories of reading development in oral as compared to silent reading? (2) How are word frequency effects developing and are changes differentially affected by reading mode? (3) Are there systematic differences between better and weaker comprehenders when reading silently vs. aloud? Results illuminate a number of differences between reading modes, including more and prolonged fixations in oral reading, along with less inter-word regressions and attenuated effects of word frequency. Weaker comprehenders were slower, especially in oral reading and showed less flexibility in the allocation of word processing time. Differences between reading modes can be explained by additional processing demands imposed by concurrent articulation and eye–voice coordination when reading aloud.     

Eye movements while reading and searching spatially transformed text: A developmental examination

The effects of spatial manipulation on eye movement when subjects either read or searched through paragraphs were examined. Adults, third, and fifth graders were presented with paragraphs which were typed normally or in alternating case (upper and lower). The spacing between the words was either normal, filled, or absent. The results show that approximately twice as many character spaces are processed during search as during reading. Subjects made more fixations of shorter duration during search than reading. The data indicated that the ability to vary the size of the perceptual unit develops with experience. When spatial cues were unavailable, all subjects resorted to a letter-by-letter-like processing strategy in reading but not in search. Although reading and search were found to be sensitive to the same types of spatial manipulations, discrepancies of span and speed suggest qualitative differences; comprehension demands during reading can account for these differences. The data were interpreted to provide support for the two-stage model of Hochberg (1970).