Eye movement control in reading: evidence against semantic preprocessing.

Prior experiments reported by Underwood and his colleagues have suggested that information about the informative parts of parafoveal words that have not yet been fixated can influence where readers fixate next. The basic finding that they have reported is that the eyes move farther into a word when the information that uniquely identifies the word is at the end of the word rather than at the beginning of the word. On the basis of such results, it has been suggested that semantic preprocessing influences eye movement behavior in reading. Some theoretical and methodological problems are raised with the prior experiments and then an attempt to replicate the finding is reported. With a highly accurate eyetracking system, the basic finding could not be replicated. An alternative account of eye movement control in reading is discussed.     

Effects of foveal priming and extrafoveal preview on object identification

The results of three different experiments suggested that the relation between an object in the fovea on fixation n and an object subsequently brought into the fovea on fixation n + 1 affects the time to identify the second object. In Experiment 1 we extended previous work by demonstrating that a previously seen related priming object speeded the time to name a target object even when a saccade intervened between the two objects. In Experiment 2 we replicated this result and further showed that the benefit on naming time was due to facilitation from the related object rather than inhibition from the unrelated object. In addition, naming of the target object was much slower in both experiments when there was not a peripheral preview of the target object on fixation n. However, because the effect of the foveal priming object was greater when the target was not present than when it was present, priming did not appear to make extraction of the extrafoveal information more efficient. In Experiment 3, fixation times were recorded while subjects looked at four objects in order to identify them. Fixation time on an object was shorter when a related object was fixated immediately before it, even though the four objects did not form a scene. The size of the facilitation was roughly comparable to that in several analogous experiments where scenes were used. The results suggest that the effects of a predictive scene context on object identification may be explainable in terms of an object-to-object or "intralevel" priming mechanism.     

Eye movements and the perceptual span in beginning and skilled readers

Four experiments are reported which examined the size of the perceptual span in second-, fourth-, and sixth-grade children, as well as adult skilled readers. The results indicated that the perceptual span in beginning readers is slightly smaller than the perceptual span of skilled readers. Using a moving window technique, it was found that the perceptual span of beginning readers extends about 11 character spaces to the right of fixation; for skilled readers, the span extends 14-15 spaces to the right of fixation. Beginning readers apparently devote more of their processing to the foveally fixated word than more proficient readers, but their perceptual span appears to be asymmetric to the right of fixation as is the case for skilled readers. The results of the experiments also indicated that the size of the perceptual span is variable and can be influenced by the difficulty of the text. It is concluded that the size of the perceptual span does not cause beginning readers' slow reading rates.     

Integrating pictorial information across eye movements

Six experiments are reported dealing with the types of information integrated across eye movements in picture perception. A line drawing of an object was presented in peripheral vision, and subjects made an eye movement to it. During the saccade, the initially presented picture was replaced by another picture that the subject was instructed to name as quickly as possible. The relation between the stimulus on the first fixation and the stimulus on the second fixation was varied. Across the six experiments, there was about 100-130 ms facilitation when the pictures were identical compared with a control condition in which only the target location was specified on the first fixation. This finding clearly implies that information about the first picture facilitated naming the second picture. Changing the size of the picture from one fixation to the next had little effect on naming time. This result is consistent with work on reading and low-level visual processes in indicating that pictorial information is not integrated in a point-by-point manner in an integrated visual buffer. Moreover, only about 50 ms of the facilitation for identical pictures could be attributed to the pictures having the same name. When the pictures represented the same concept (e.g., two different pictures of a horse), there was a 90-ms facilitation effect that could have been the result of either the visual or conceptual similarity of the pictures. However, when the pictures had different names, only visual similarity produced facilitation. Moreover, when the pictures had different names, there appeared to be inhibition from the competing names. The results of all six experiments are consistent with a model in which the activation of both the visual features and the name of the picture seen on the first fixation survive the saccade and combine with the information extracted on the second fixation to produce identification and naming of the second picture.     

EVENT-RELATED BRAIN POTENTIALS, EYE MOVEMENTS, AND READING

Abstract— This article compares studies that use event-related brain potential (ERP) and eye movement data to examine changes in reading behavior when a text is read twice. Although the types of information provided by these methodologies are different, both indicate that rereading a text facilitates many aspects of processing. ERPs provide a method for measuring comprehension and memory processes separately, while eye movements provide a continuous record of performance and allow changes in reading behavior to be localized to specific words. The results from these studies are compatible. However, converging evidence is not always found when different paradigms are contrasted, and diverging results can provide important information. To facilitate comparison across experiments, we suggest using a common set of materials for both paradigms. We conclude that comparing the results of research based on more than one paradigm provides a more complete understanding of the processes involved in reading.     

Role of spatial location in integration of pictorial information across saccades

Identification of a fixated object in a visual display is facilitated by integrating information from a preview of that object in the periphery with information extracted on the subsequent foveal fixation (Pollatsek, Rayner, & Collins, 1984). These experiments investigated the extent to which this integration is dependent on the spatial location of the information remaining constant. Two preview objects were presented in the periphery; Ss fixated that region and named a single target object that appeared in the same spatial location in which one of the two preview objects had been presented. Of primary interest was the facilitative effect when a preview object was identical to the target object as a function of whether they were in the same spatial location. The major finding was that although there was a small effect of switching, there was still a substantial preview benefit even when the location of the identical object switched. In addition, the switching effect did not interact with the level of identity between the preview and target. There was also a preview benefit in conditions in which there were no eye movements and the preview and target objects were at least 5 degrees apart. Thus, the data indicate that the process object identification is relatively insensitive to location information and that object information and location information are coded fairly independently.     

PHONOLOGICAL CODES ARE AUTOMATICALLY ACTIVATED DURING READING:

Abstract— Subjects read sentences containing target words that were homophones (words with a single pronunciation but different spellings) while their eye movements were recorded A prime word was presented briefly at the onset of fixation on the target region The prime for a given target (e g, beach) was either identical to the target (beach, a phonologically similar word (the homophone beech), a visually similar nonhomophone (bench), or a dissimilar word (noise) Phonological priming effects were assessed by comparing fixation times on the target when It was preceded by the homophone versus the visually similar word Results suggest that phonological codes are automatically activated during eye fixations in reading     

Effects of contextual constraint on eye movements in reading: A further examination

The effect of contextual constraint on eye movements in reading was examined by asking subjects to read sentences that contained a target word that varied in contextual constraint; high-, medium-, or low-constraint target words were used. Subjects fixated low-constraint target words longer than they did either high- or medium-constraint target words. In addition, they skipped high-constraint words more than they did either medium- or low-constraint target words. The results further confirm that contextual constraint has a strong influence on eye movements during reading.