IntroductionIntroduction

To know how perceptual and attentional processes and properties of words guide the eyes through a sentence, the following issues are particularly important :

- The extent to which eye-movement behaviour is affected by low-level oculomotor factors and higher-level cognitive processes.

- Whether readers process information from more than one word at a time.

Determinant of eye movement control in readingDeterminant of eye movement control in readingWord frequency, contextual predictability or word length effects are particularly robust. These factors are the main predictors used in the models of eye movement control in reading like E-Z Reader (Pollatsek et al., 2006) or SWIFT (Engbert et al., 2005).

However, very few studies explored the relative weights of a large number of factors on the spatial and temporal aspects of oculomotor behaviour in reading. The repeated-measures multiple regression analysis (rmMRA), as described by Lorch and Myers (1990), provides measures of effect magnitude. This procedure involves a single regression analysis on the entire data set, each individual observation constituting a separate case in the analysis.

Parafoveal-on-foveal effectsParafoveal-on-foveal effectsWith this method and from a corpus in German, Kliegl, Nuthmann, & Engbert (2006) studied the effects of previous and next word characteristics (frequency, predictability and length) on the currently fixated word. From the observation of parafoveal-on-foveal effects (effects of word n+1 characteristics on the processing of word n) they concluded of a parallel processing of several words at a time.

Present study Present study To study a larger number of word characteristics and to estimate their relative weights on oculomotor behavior.

To check if these findings can be generalize across languages.

To verify if the parafoveal-on-foveal effects could be found with a more controlled material and in some other languages.

English versus French: Determinants of eye movements control in readingEnglish versus French: Determinants of eye movements control in reading

Sébastien Miellet, Cyril Pernet, Patrick J. O’Donnell, & Sara C. SerenoSébastien Miellet, Cyril Pernet, Patrick J. O’Donnell, & Sara C. Sereno Department of Psychology, University of GlasgowDepartment of Psychology, University of Glasgow

MethodMethod

Participants:Participants: 20 native English speakers and 20 native French speakers, normal vision, no reading difficulty

Apparatus: Apparatus: Fourward Technologies Generation 5.5 dual-Purkinje eyetracker

Procedure:Procedure: Participants read sentences in their native language while their eye movements were monitored. Y/N comprehension question were presented on third the trials.

Materials and DesignMaterials and DesignIn each language 100 experimental sentences (exact translation) including a adjective-noun target pair.

10 predictors were associated to the 200 target words:

- Language: English or French

- Position: 1st or 2nd in the adjective-noun target pair. The first word being the adjective in English and the noun in French

- Length: number of letters

- ln of Frequency: from British National Corpus for English and Lexique3 corpus (New et al., 2001) for French

- Predictability: from a Cloze task

-Plausibility: from a judgment rating task

-Ln of Frequency 2: of the second word of the adjective-noun target pair

-Length 2: of the second word of the adjective-noun target pair

-Launch site: distance of the previous fixation

-Initial fixation location (IFL): location (in number of letters) of the first fixation on the word.

References and acknowledgmentsReferences and acknowledgments British National Corpus. (1995). http://www.natcorp.ox.ac.uk/

Engbert, R., Nuthmann, A., Richter, E.M., & Kliegl, R. (2005). A dynamical model of saccade generation during reading. Psychological Review, 112, 777-813.

Kliegl, R. Nuthmann, A., & Engbert, R. (2006). Tracking the mind during reading: The influence of past, present, and future words on fixation durations. Journal of Experimental Psychology: General, 135, 12-35.

Lorch, R.F., & Myers, J.L. (1990). Regression analyses of repeated measures data in cognitive research. Journal of Experimental Psychology: Learning, Memory & Cognition, 16, 149-157.

New, B., Pallier, C., Ferrand, L., & Matos, R. (2001). Une base de données lexicales du français contemporain sur internet: LEXIQUE (http://www.lexique.org/). L'Année Psychologique, 101, 447-462.

Pollatsek, A., Reichle, E.D., & Rayner, K. (2006). Tests of the E-Z Reader model: Exploring the interface between cognition and eye-movement control. Cognitive Psychology, 52, 1-56.

This work was supported by an ERSC Research Grant to To S.C. Sereno and P.J. O’Donnell. Corresponding author: miellet@psy.gla.ac.uk

DiscussionDiscussion- We obtained the relative weight of various predictors on the fixation durations in reading English and French. These findings can help to inform models of eye movement control in reading.

- On some indexes, the plausibility accounts of a larger amount of variance than the predictability on the fixation durations.

- Further investigations are needed to make a direct comparison of the weight of various contextual constraint indices (predictability, plausibility, transitional probability,…) in order to select the best index for the models.

- The weight of the variables used in the oculomotor models in reading must be adapted depending on the language.

- The regression models on the fixation durations on the 1st word of the pair allowed us to look for some parafoveal-on-foveal effects. We did not observe any clear lexical parafoveal-on-foveal effect but an influence of some characteristics of the word n+1 on the fixation durations on n exists.

ms

No effect of the language on Single Fixation Durations (SFD), Gaze Duration (GD) or Total Fixation Duration (TFD) Strong effects of our set of predictors Interaction between the language and the predictors

- The initial fixation location has a stronger relative influence on the early fixation durations (importance of the number and gender markers)

Data points

Obse rved GDPredicted GD

Fit between predicted and observed GD

R2 = 0.4597, p =0

Static modelsStatic models.

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Y Gp X Subjects Gp*X Subjects*XGD language Predictors

R2*100 = 0.008 11.31 7.15 1.03 26.47 p = 0.575 0 0

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Matrices of the statistic model for gaze duration (GD)with percentages of explained variance for GD and p values

ln FrequencyIFLLaunch siteLengthPlausibilityLength 2ln Frequency 2PredictabilityPosition

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Relative part of variance explained by our predictors in English and in Frenchfor early to late fixation durations

Parafoveal-on-foveal effectsParafoveal-on-foveal effects

Rsquare F p betaln frequency 0.0277 41.3820 0.0000 -11.8069Length 2 0.0030 4.4642 0.0014 -4.1132Predictability 0.0020 3.0045 0.0128 183.2258Length 0.0006 0.8531 0.6179 3.6934Launch site 0.0004 0.5386 0.8859 2.5037Predictability 2 0.0002 0.3586 0.9756 -14.5816ln frequency 2 0.0002 0.2670 0.9938 -1.1236IFL x ln frequency 2 0.0000 0.0741 1.0000 -1.3050IFL 0.0000 0.0737 1.0000 5.7326IFL x predictability2 0.0000 0.0016 1.0000 0.0074plaus 0.0000 0.0001 1.0000 -0.0253

EnglishRsquare F p beta

ln frequency 0.0157 26.0791 0.0000 -7.7123Launch site 0.0037 6.1959 0.0002 7.3310Length 0.0016 2.7156 0.0210 5.6613IFL x predictability2 0.0015 2.5709 0.0271 0.0061Plausibility 0.0014 2.4044 0.0366 -3.1937Predictability 2 0.0007 1.1175 0.4037 39.4500ln frequency 2 0.0006 1.0044 0.4887 1.4365IFL 0.0002 0.3462 0.9791 -4.2206IFL x ln frequency 2 0.0001 0.1155 0.9999 3.1878Predictability 0.0001 0.0909 1.0000 -59.7966Length 2 0.0000 0.0235 1.0000 0.3125

FRENCH

In English: No effects of the frequency or the predictability of the 2nd word Effect of the length of the 2nd word of the pair on the gaze durations on the 1st word.

In French: No effects of the frequency or the predictability of the 2nd wordInteraction between the predictability of the 2nd word and the initial fixation location