About the global effect and the critical role of retinal eccentricity: Implications for eye movements in reading

In the present paper, I review evidence for the universality of the global effect, i.e. the general tendency to move the eyes towards the centre of gravity of the peripheral configu-ration, and show that the effect is strongly constrained by the retinal location of the stimuli. First, stimuli that are displayed in a central foveal region of a 1-1.5° radius fail to deviate the eyes in a centre-of-gravity manner; this is referred to as the foveal dead zone. Second, the stimuli that are too eccentric relative to the saccade target and/or the main stimulation site are filtered out. These limitations reflect physiological constraints and the dynamics of the patterns of activity in a visual saliency map. They form the basis for a low-level centre-of-gravity type account of eye guidance in natural perceptual tasks such as reading

The influence of semantic context on initial eye landing sites in words

To determine the role of ongoing processing on eye guidance in reading, two studies examined the effects of semantic context on the eyes' initial landing position in words of different levels of processing diffculty. Results from both studies clearly indicate a shift of the initial fixation location towards the end of the words for words that can be predicted from a prior semantic context. However, shifts occur only in high-frequency words and with prior fixations close to the beginning of the target word. These results suggest that ongoing perceptual and linguistic processes can affect the decision of where to send the eyes next in reading. They are explained in terms of the easiness of processing associated with the target words when located in parafoveal vision. It is concluded that two critical factors might help observing effects of linguistic variables on initial landing sites, namely, the frequency of the target word and the position where the eyes are launched from as regards to the beginning of the target word. Results also provide evidence for an early locus of semantic context effects in reading

The role of object affordances and center of gravity in eye movements toward isolated daily-life objects

International audienceThe purpose of the current study was to investigate to what extent low-level versus high-level effects determine where the eyes land on isolated daily-life objects. We operationalized low-level effects as eye movements toward an object's center of gravity (CoG) or the absolute object center (OC) and high-level effects as visuomotor priming by object affordances. In two experiments, we asked participants to make saccades toward peripherally presented photographs of graspable objects (e.g., a hammer) and to either categorize them (Experiment 1) or to discriminate them from visually matched nonobjects (Experiment 2). Objects were rotated such that their graspable part (e.g., the hammer's handle) pointed toward either the left or the right whereas their action-performing part (e.g., the hammer's head) pointed toward the other side. We found that early-triggered saccades were neither biased toward the object's graspable part nor toward its action-performing part. Instead, participants' eyes landed near the CoG/OC. Only longer-latency initial saccades and refixations were subject to high-level influences, being significantly biased toward the object's action-performing part. Our comparison with eye movements toward visually matched nonobjects revealed that the latter was not merely the consequence of a low-level effect of shape, texture, asymmetry, or saliency. Instead, we interpret it as a higher-level, object-based affordance effect that requires time, and to some extent also foveation, in order to build up and to overcome default saccadic-programming mechanisms

Linguistic processes do not beat visuo-motor constraints, but they modulate where the eyes move regardless of word boundaries: Evidence against top-down word-based eye-movement control during reading

International audienceWhere readers move their eyes, while proceeding forward along lines of text, has long been assumed to be determined in a top-down word-based manner. According to this classical view, readers of alphabetic languages would invariably program their saccades towards the center of peripheral target words, as selected based on the (expected) needs of ongoing (word-identification) processing, and the variability in within-word landing positions would exclusively result from systematic and random errors. Here we put this predominant hypothesis to a strong test by estimating the respective influences of language-related variables (word frequency and word predictability) and lower-level visuo-motor factors (word length and saccadic launch-site distance to the beginning of words) on both word-skipping likelihood and within-word landing positions. Our eye-movement data were collected while forty participants read 316 pairs of sentences, that differed only by one word, the prime; this was either semantically related or unrelated to a following test word of variable frequency and length. We found that low-level visuo-motor variables largely predominated in determining which word would be fixated next, and where in a word the eye would land. In comparison, language-related variables only had tiny influences. Yet, linguistic variables affected both the likelihood of word skipping and within-word initial landing positions, all depending on the words’ length and how far on average the eye landed from the word boundaries, but pending the word could benefit from peripheral preview. These findings provide a strong case against the predominant word-based account of eye-movement guidance during reading, by showing that saccades are primarily driven by low-level visuo-motor processes, regardless of word boundaries, while being overall subject to subtle, one-off, language-based modulations. Our results also suggest that overall distributions of saccades’ landing positions, instead of truncated within-word landing-site distributions, should be used for a better understanding of eye-movement guidance during reading

Les administrateurs de la santé dans l’espace parisien au xixe siècle

Une enquête collective, concernant les administrateurs de la santé et de l’hygiène publique à Paris au xixe siècle, a suscité le besoin de cartographier les trajectoires individuelles et les pratiques sociales du personnel attaché aux organismes de santé. Ce projet a nécessité la création d’une information spatiale : le réseau des ilôts géoréférencés de Paris, en 1826 et en 1885.Par la mise en œuvre d’une approche SIG et de géotraitements, l’adressage postal (Geocoding) permet la spatialisation des adresses parisiennes des administrateurs en mettant en relation les informations spatiales (le parcellaire urbain), les informations thématiques (les adresses), et ce pour toute la période.L’analyse spatiale pourra mettre en lumière des phénomènes de proximité sociale entre des groupes ou des couches professionnelles différentes et permettra d’étudier les changements structuraux du tissu urbain, à travers l’évolution temporelle des implantations des différents groupes socio-professionnels.The Administrators of Health Care in 19th Century Paris Space. A collective examination of the Administrators of health and public hygiene in 19th century Paris brought up the possibility of mapping individuals’ displacement as well as the social practices of health organizations personnel.The project required the creation of spatial information, in other words, the network of georeferential areas within Paris in 1826 and in 1885. Using a GIS and Geocoding it was possible to spatialize administrators’ parisian addresses by bringing together spatial information (urban land divisions) and thematic information (the addresses) for the entire period.Spatial analysis is useful both in exploring social proximity among groups or various professional categories and also in studying structural change in the urban fabric, through the lens of the temporal development of location among various socio-professional groups

Going with the flow? The endogenous/exogenous influences on gaze control in dynamic scenes

This document contains all abstracts of the 16th European Conference on Eye Movements, August 21-25 2011 in Marseille, France. It was a real honour and a great pleasure to welcome more than 500 delegates to Marseille for the 16th edition of the European Conference on Eye Movements. The series of ECEM conferences started in 1981 under the auspices of Rudolf Groner in Bern. This year, we therefore celebrated the 30th Anniversary of ECEM. For this special occasion we had as a special guest Rudolf Groner, and honoured Alan Kennedy and George W. McConkie for their contributions to our field in two special symposia. We had the pleasure of listening to six keynote lectures given respectively by Patrick Cavanagh, Ralf Engbert, Edward L. Keller, Eileen Kowler, Rich Krauzlis and Gordon E. Legge. These exceptional scientific events were nicely complemented by all submissions, which made the ECEM 2011 program a very rich and interdisciplinary endeavor, comprising 19 symposia, 243 talks and 287 poster presentations, and a total of about 550 participants. The conference opened with an address given by Denis Bertin, vice president of the scientific committee of the University of Provence, and representing Jean-Paul Caverni, President of the University of Provence. It closed with Rudolf Groner’s address and the awarding of the best poster contributions by students and postdocs. This year, three posters were awarded; the first prize was offered by SR Research, the second prize was given by the Cognitive Science Society, and the third, the Rudolf Groner Prize, was offered by the ECEM organizing committee. The conference was held on the St Charles campus of the University of Provence, and to mark the return of ECEM in Southern Europe, many events including lunches, coffee breaks, aperitifs and poster sessions took place outside under the trees of our campus. Luckily, the sun was with us for the five days of the conference ! Françoise, Stéphanie, Stéphane, Eric & Lauren