Recent studies of eye movements in reading and other information processing tasks, such as music reading, typing, visual search, and scene perception, are reviewed. The major emphasis of the review is on reading as a specific example of cognitive processing. Basic topics discussed with respect to reading are (a) the characteristics of eye movements, (b) the perceptual span, (c) integration of information across saccades, (d) eye movement control, and (e) individual differences (including dyslexia). Similar topics are discussed with respect to the other tasks examined. The basic theme of the review is that eye movement data reflect moment-to-moment cognitive processes in the various tasks examined. Theoretical and practical considerations concerning the use of eye movement data are also discussed. Many studies using eye movements to investigate cognitive processes have appeared over the past 20 years. In an earlier review, I (Rayner, 1978b) argued that since the mid-1970s we have been in a third era of eye movement research and that the success of research in the current era would depend on the ingenuity of researchers in designing interesting and informative

The relationship between saccadic eye movements and covert orienting of visual spatial attention was investigated in two experiments. In the first experiment, subjects were required to make a saccade to a specified location while also detecting a visual target presented just prior to the eye movement. Detection accuracy was highest when the location of the target coincided with the location of the saccade, suggesting that subjects use spatial attention in the programming and/or execution of saccadic eye movements. In the second experiment, subjects were explicitly directed to attend to a particular location and to make a saccade to the same location or to a different one. Superior target detection occurred at the saccade location regardless of attention instructions. This finding shows that subjects cannot move their eyes to one location and attend to a different one. The results of these experiments suggest that visuospatial attention is an important mechanism in generating voluntary saccadic eye movements. We selectively explore the visual panorama by means of fixations lasting about a quarter of a second interspersed with rapid changes of eye position lasting about 50 msec. The pattern of these fixations and the choice of where to send the eye next is not random but instead appears to be guided (Rayner & Pollatsek, 1989). Yarbus (1967), for example, pointed out that the pattern of eye fixations that a given observer produces is influenced by properties of the scene as well as the goals and interests of the perceiver. Examples of this principle have been provided by many demonstrations that fixations in reading are influenced by properties of the text, such as word length (Rayner, 1975), as well as knowledge of the reader in the form of expectations, text schemas, and so on (Just & Carpenter, 1987; Kowler, 1991). What is the mechanism that chooses the destination of each subsequent saccade? A likely candidate is the spatial attention system, a mechanism that can operate within a fixation to selectively process information from different

Recent computational models of cognition have made good progress in accounting for the visual processes needed to encode external stimuli. However, these models typically incorporate simplified models of visual processing that assume a constant encoding time for all visual objects and do not distinguish between eye movements and shifts of attention. This paper presents a domain-independent computational model, EMMA, that provides a more rigorous account of eye movements and visual encoding and their interaction with a cognitive processor. The visual-encoding component of the model describes the effects of frequency and foveal eccentricity when encoding visual objects as internal representations. The eye-movement component describes the temporal and spatial characteristics of eye movements as they arise from shifts of visual attention. When integrated with a cognitive model, EMMA generates quantitative predictions concerning when and where the eyes move, thus serving to relate higher-level cognitive processes and attention shifts with lower-level eye-movement behavior. The paper evaluates EMMA in three illustrative domains — equation solving, reading, and visual search — and demonstrates how the model accounts for aspects of behavior that simpler models of cognitive and visual processing fail to explain.

This article describes and evaluates a class of methods for performing automated analysis of eye-movement protocols. Although eye movements have become increasingly popular as a tool for investigating user behavior, they can be extremely difficult and tedious to analyze. In this article we propose an approach to automating eye-movement protocol analysis by means of tracing—relating observed eye movements to the sequential predictions of a process model. We present three tracing methods that provide fast and robust analysis and alleviate the equipment noise and individual variability prevalent in typical eye-movement protocols. We also describe three applications of the tracing methods that demonstrate how the methods facilitate the use of eye movements in the study of user behavior and the inference of user intentions. 1.

Dividing attention across multiple words occasionally results in misidentifications whereby letters apparently migrate between words. Previous studies have found that letter migrations preserve withinword 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. A key issue that must be addressed in any theory of visual word recognition is how to code for letter position: Without coding of position, it is not possible to distinguish anagrams like CAT and ACT. Although relatively little empirical work has been directed at assessing the relative merits of different letter coding schemes, the choice of coding scheme plays a central role in the performance of

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It is assumed that too low values for optimal field of view in magnifier reading were obtained in the past by applying the 'Drifting Text ' Technique [1,3,4] in which the subjects had no control of the movements of the magnified image. On the basis of the view that reading involves alternating sequences of locating and recognizing textual information [9], it is argued that part of the magnified image is required for the movement control of the visual display. Higher values are predicted than the 1-6 characters proposed in the model of Whittaker and Lovie-Kitchin [1]. 14 Male and female subjects with a macular degeneration ranging in age from 20 to 82 years of age participated in an experiment to determine the optimal field of view in CCTV-magnifier reading. Large effects of width and height are found on reading rate and the data suggest that the optimal values are even higher than the maximum value of 12 characters that could be technically realized in the present experiment. Large age effects are found in both reading rate and smoothness of control of the platform. The data on the movements of the platform and the eyes are discussed. It is concluded that the elderly subject applied another strategy to move the platform than the other subjects. In all subjects large variations are observed in the velocity of transportation of the platform. It is assumed that these variations signal the flexibility of the motor control process that is required to adapt the reading process as a whole to fluctuations in the comprehension process.

This paper explains and documents a methodology which facilitates process tracing studies of information acquisition and decision making. 1.1 Alternative Process Tracing Methods. The two process tracing methods of greatest interest to decision researchers have been: (1) verbal protocol analysis, and (2) the analysis of information acquisition behavior. Verbal protocol analysis takes as data the continuous verbal reports provided by a subject who is asked to "think aloud" while performing a decision task. An utterance at a particular point in time is taken to indicate knowledge or an operation at that time (Newell & Simon, 1972). A model of how people respond to instructions to think aloud is developed by Ericsson and Simon (1980; 1984). Ericsson and Simon argue forcefully for the validity of verbal protocols in providing a high density of observations of the intermediate stages of processing, and they provide numerous examples of the successful use of verbal protocols

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The planning of the refixation saccade, i.e. the second saccade on 9- and 11-letter-strings, was assessed in two reading experiments that examined the influence of a length change at different times during the first fixation on a letter string. The results showed that the saccadic system was able to modify the first motor program if the new length information was available 150–190 ms before the execution of the refixation saccade. Moreover, the amplitude of the refixation saccade was found to be planned as a constant movement relative to the length of the item, regardless of the position of the initial fixation on the item. Finally, the refixation saccade seems to be preprogrammed before the primary saccade, depending on the length integrated at that time. Overall, these results suggest that the refixation saccade is programmed on the basis of the intrinsic properties of the item, such as its length. © 2000 Published by Elsevier Science Ltd.