Ralph Radach

Reading as a perceptual process

Section and selected chapter headings: Visual Word Processing. Traces of print along the visual pathway (T.A. Nazir). Processing of Finnish compound words in reading (J. Hyona, A. Pollatsek). Attention, Information Processing and Eye Movement Control. Relations between spatial and temporal aspects of eye movement control (R. Radach, D. Heller). Eye guidance and the saliency of word beginnings in reading text (W. Vonk et al.). Phonology in Reading. The assembly of phonology in Italian and English: consonants and vowels (L. Colombo). Do readers use phonological codes to activate word meanings? Evidence from eye movements (M. Daneman, E.M. Reingold). Syntax and Discourse Processing. Decoupling syntactic parsing from visual inspection: the case of relative clause attachment in French (J. Pynte, S. Colonna). Unrestricted race: a new model of syntactic ambiguity resolution (R.P.G. van Gompel et al.). Models and Simulations. Eye fixation durations in reading: models of frequency distributions (G.W. McConkie, B.P. Dyre). Subject index.

Chapter 2 – Definition and Computation of Oculomotor Measures in the Study of Cognitive Processes

Publisher Summary This chapter reviews methodological choice points that need to be considered when raw data are used to define basic oculomotor events, such as fixations and saccades. Oculomotor measures provide distinct methodological advantages in the study of cognitive and perceptual processes. They appear sensitive to a wide range of “cognitive processes” and can be obtained under relatively natural task conditions. Derivation and use of these measures is not, however, straightforward. The chapter also considers the usage of these oculomotor events for the indexing of perceptual and cognitive processes. Attention is given to viewing duration measures, as these are used as the primary indicator of cognitive processes in eye movement research. The discussion is limited in that the raising of measurement-related and methodological issues is not followed by the presentation of specific solutions. There are no “de facto” standard measurements that define basic oculomotor events (fixations and saccades). Furthermore, processing assumptions that underlie the translation of oculomotor events into measures of cognitive processes are increasingly challenged. It remains unclear whether some definitions of oculomotor events and some oculomotor measures are more effective than others.

Theoretical perspectives on eye movements in reading: Past controversies, current issues, and an agenda for future research

The study of eye movements has become a well established and widely used methodology in experimental reading research. This Introduction provides a survey of some key methodological issues, followed by a discussion of major trends in the development of theories and models of eye movement control in fluent reading. Among the issues to be considered in future research are problems of methodology, a stronger grounding in basic research, integration with the neighbouring area of research on single word recognition, more systematic approaches to model evaluation and comparison, and more work on individual variation and effects of task demands in reading.

Chapter 21 – Foundations of an Interactive Activation Model of Eye Movement Control in Reading

Publisher Summary Glenmore is an interactive-activation model of eye-movement control in reading. The model decouples the decision when to move the eyes from the word recognition process. The time course of activity in a “fixate centre” determines the triggering of a saccade. The other main feature of the model is the use of a saliency map that acts as an arena for the interplay of bottom-up visual features of the text and top-down lexical features. These factors combine to create a pattern of activation that selects one word as the saccade target. One of the goals of Glenmore is to explore the class of dynamical model, one that allows the interplay of factors from multiple levels of representation. The most appropriate class of modeling frameworks for this approach would be connectionist models and interactive activation models. The connectionist architecture of the Glenmore model is relatively simple, comprising input units, letter units, saliency units, and word units, as well as a “fixate centre” unit that controls the decision when to execute a new saccade. This decision is based on the general level of activity in the letter units; once activation in the fixate centre falls below a given threshold, a saccade is targeted to the most salient word ‘blob” on the saliency map.

Chapter 4 – Determinants of Fixation Positions in Words During Reading

Publisher Summary This chapter explores data concerning where the eyes land in words, or landing position distributions. The current investigation determines whether the model of this study, (which was originally developed to account for progressive inter-word saccades), could be extended to two other conditions, namely, refixations and interword regressive saccades. Interword regressive saccades showed different landing position characteristics than other cases. Neither word length nor distance from launch site was found to have much effect on the landing positions of these saccades, and the saccadic range effect, typically found with progressive saccades, was found absent. Interword regressions appeared to have been sent to the centers of words, with landing position distributions in “optimal” and “preferred” viewing positions, similar. Issues regarding the basis for eye movement control during reading are studied. It is argued that eye movement controls are discrete, based on the selection of word targets, rather than a graded type of control, and some of the implications of this position are explored. It has been noticed that even when a variable produces a significant effect on saccade length, it is likely that the lengths of relatively few of the saccades may have actually been changed.

Oculomotor and linguistic determinants of reading development: A longitudinal study

We longitudinally assessed the development of oculomotor control in reading from second to fourth grade by having children read sentences with embedded target words of varying length and frequency. Additionally, participants completed oculomotor (pro-/anti-saccades) and linguistic tasks (word/picture naming), the latter containing the same item material as the reading task. Results revealed a 36% increase of reading efficiency. Younger readers utilized a global refixation strategy to gain more time for word decoding. Linguistic rather than oculomotor skills determined the development of reading abilities, although naming latencies of fourth graders did not reliably reflect word decoding processes in normal sentence reading.

The role of global top-down factors in local eye-movement control in reading

Although the development of the field of reading has been impressive, there are a number of issues that still require much more attention. One of these concerns the variability of skilled reading within the individual. This paper explores the topic in three ways: (1) it quantifies the extent to which, two factors, the specific reading task (comprehension vs. word verification) and the format of reading material (sentence vs. passage) influence the temporal aspects of reading as expressed in word-viewing durations; (2) it examines whether they also affect visuomotor aspects of eye-movement control; and (3) determine whether they can modulate local lexical processing. The results reveal reading as a dynamic, interactive process involving semi-autonomous modules, with top-down influences clearly evident in the eye-movement record.

Time Course of Linguistic Information Extraction From Consecutive Words During Eye Fixations in Reading

Sequential attention shift models of reading predict that an attended (typically fixated) word must be recognized before useful linguistic information can be obtained from the following (parafoveal) word. These models also predict that linguistic information is obtained from a parafoveal word immediately prior to a saccade toward it. To test these assumptions, sentences were constructed with a critical pretarget-target word sequence, and the temporal availability of the (parafoveal) target preview was manipulated while the pretarget word was fixated. Target viewing effects, examined as a function of prior target visibility, revealed that extraction of linguistic target information began 70-140 ms after the onset of pretarget viewing. Critically, acquisition of useful linguistic information from a target was not confined to the ending period of pretarget viewing. These results favor theoretical conceptions in which there is some temporal overlap in the linguistic processing of a fixated and parafoveally visible word during reading.

Chapter 7 – Relations Between Spatial and Temporal Aspects of Eye Movement Control

Abstract Models of eye movement control in reading and other complex cognitive tasks need to specify the oculomotor, perceptual and cognitive variables that determine when an eye movement is initiated and where it is intended to land. In recent years a large amount of data has accumulated on both aspects of eye guidance, but far less attention has been paid to their interrelations. The dominant view in the literature is that spatial and temporal aspects of eye movement control are independent and need to be accounted for separately. This is in contrast to evidence suggesting that influences of fixations on subsequent saccades and vice versa exist as part of local fixation patterns. In this chapter a number of specific hypotheses are developed and examined on the basis of a very large corpus of reading data and crucial aspects tested using data from two recent reading experiments. Our results indicate that there are significant influences of where-parameters on when-decisions: processing time savings on the current fixation appear to be a function of the distance to the preceding fixation location. On the other hand there is only very limited evidence for influences of when-decisions on subsequent where-computations: fixation durations do generally not predict fixation positions on the next word. The proposition that fixation durations are inflated before word-skipping does not find empirical support in our data.

Eye movements in reading: Some theoretical context

The study of eye movements has proven to be one of the most successful approaches in research on reading. In this overview, it is argued that a major reason for this success is that eye movement measurement is not just a methodology—the control of eye movements is actually part and parcel of the dynamics of information processing within the task of reading itself. Some major developments over the last decade are discussed with a focus on the issue of spatially distributed word processing and its relation to the development of reading models. The survey ends with a description of two newly emerging trends in the field: the study of continuous reading in non-Roman writing systems and the broadening of the scope of research to encompass individual differences and developmental issues.