Thierry Baccino | Universite Paris-8, France (original) (raw)

Papers by Thierry Baccino

Léger, L., Chêne, D. , Baccino, T. & Tijus C. (2003). The Effect of Semantic Relatedness and Typi... more Léger, L., Chêne, D. , Baccino, T. & Tijus C. (2003). The Effect of Semantic Relatedness and Typicality upon Visual Detection of a Target. Poster presented at CogniSci 2003, The 25th annual Meeting of the Cognitive Science Society, July 31 Aug 2 2003. CDrom.

Revue d'Interaction Homme- …, 2005

Abstract. Usability studies for web sites used to deal with text layout and text content in order... more Abstract. Usability studies for web sites used to deal with text layout and text content in order to improve how information can be better located and used. The aim of this study was to find out what were the main visual or lexical factors that affected word detection in a list and ...

In the era of small screens, traditional reading (i.e. left-to-right, top-to-bottom) is called in... more In the era of small screens, traditional reading (i.e. left-to-right, top-to-bottom) is called into question and
rapid serial visual presentation (RSVP) represents one of the main alternatives. RSVP consists of displaying
in sequential order one or more words at a time, thus minimizing saccades and eye blinks. Recently, a
RSVP application has received a lot of media attention: it is the case of Spritz. According to Spritz’s developers,
the elimination of saccades should reduce visual fatigue and improve comprehension. In this study,
we had people read on a computer screen a selected part of a book either with Spritz or in the traditional
way. Results seem to contradict these claims. The fact that Spritz suppresses parafoveal processing and
regressions (i.e. rereadings of words) negatively affected literal comprehension. Furthermore, the important
reduction of eye blinks observed for Spritz might contribute to the increase of visual fatigue.

We investigated the conjoint effect of screen luminance and ambient illuminance on visual fatigue... more We investigated the conjoint effect of screen luminance and ambient illuminance on visual fatigue and arousal during prolonged digital reading (one hour) by means of a multidimensional approach based on eye, performance and subjective measures. Two levels of screen luminance (low, high) and two levels of ambient illuminance (low, high) were tested in a 2x2 between-subjects design in which participants were arbitrarily allocated to four groups, one for each combined level of luminance and illuminance. Results showed that reading under high levels of screen luminance increases visual fatigue, as reflected by a decrease of eye blinks. Concerning arousal, exposure to higher levels of either luminance or illuminance increased alertness and performance. Faster saccades, increased reading speed and less microsaccades were found under high screen luminance. Less regressive saccades and shorter reaction times were observed under high ambient illuminance. However, the reason why some of these measures are sensitive to screen luminance while other to ambient illuminance remains unknown. These findings might have practical implications for the implementation of adaptive brightness solutions and for the online detection of both visual fatigue and arousal levels during digital reading.

The food sensory science community has recently shown an increasing interest towards the measure... more The food sensory science community has recently shown an increasing interest towards the
measurement of emotions induced by product consumption. In this paper, we propose a
standard method to objectively and quantitatively explore emotions in tasting situations
through measurement and analysis of pupil diameter. Pupillometry is a well-known method
for investigating cognitive load and emotional effects. However, since a standard method to
analyze pupil response data is lacking, we provide here a guided methodology, from data
acquisition to data processing. An example of an application is also provided. The advantages
and major drawbacks of this method are discussed.

We propose a method based on wavelet transform and neural networks for relating pupillary behavio... more We propose a method based on wavelet transform and neural networks for relating pupillary behavior to psychological stress. We tested the proposed method by recording pupil diameter and electrodermal activity during a simulated driving task. Self-report measures were also collected. Participants performed a baseline run with the driving task only, followed by three stress runs where they were required to perform the driving task along with sound alerts, the presence of two human evaluators, and both. Self-reports and pupil diameter successfully indexed stress manipulation, and significant correlations were found between these measures. However, electrodermal activity did not vary accordingly. After training, our four-way parallel neural network classifier could guess whether a given unknown pupil diameter signal came from one of the four experimental trials with 79.2 % precision. The present study shows that pupil diameter signal has good discriminating power for stress detection.
We propose a method based on wavelet transform and neural networks for relating pupillary behavior to psychological stress. We tested the proposed method by recording pupil diameter and electrodermal activity during a simulated driving task. Self-report measures were also collected. Participants performed a baseline run with the driving task only, followed by three stress runs where they were required to perform the driving task along with sound alerts, the presence of two human evaluators, and both. Self-reports and pupil diameter successfully indexed stress manipulation, and significant correlations were found between these measures. However, electrodermal activity did not vary accordingly. After training, our four-way parallel neural network classifier could guess whether a given unknown pupil diameter signal came from one of the four experimental trials with 79.2 % precision. The present study shows that pupil diameter signal has good discriminating power for stress detection.

Electronic devices such as tablets often imply new postural behavior in our everyday life and lit... more Electronic devices such as tablets often imply new postural behavior in our everyday life and little is known about the influence of these postures on cognitive processes. In this study, postural aspects of reading on digital tablets are investigated to test whether reading speed or comprehension may be affected by different positions of the head or of the device. The first aim of this study is to evaluate the effect of a lateral tilt of the head and/or a tablet on reading performance. We found that a small amount of tilt did not impact reading, subjects were able to adapt to this situation. For each eye tracking metric, there was a strong correlation between every condition of head and tablet tilt (for each one, r > 0.73). Tilting the head or some particular visual stimuli can also lead to a specific movement of the eyes called cycloversion. A second experiment was designed to ascertain the presence of such eye movements when reading on tablet. It emerged that reading on a tablet induced this movement, which could explain, to a certain extent, the adaptation we observed in the first experiment.

An experiment was conducted in a driving simulator to test how eye-movement patterns evolve over ... more An experiment was conducted in a driving simulator to test how eye-movement patterns evolve over time according to the decision-making processes involved in a driving task. Participants had to drive up to a crossroads and decide to stop or not. The decision-making task was considered as the succession of two phases associated with cognitive processes: Differentiation (leading to a prior decision) and Consolidation (leading to a ﬁnal decision). Road signs (Stop, Priority and GiveWay) varied across situations, and the stopping behavior (Go and NoGo) was recorded. Saccade amplitudes and ﬁxation durations were analyzed. Speciﬁc patterns were found for each condition in accordance with the associated processes: high visual exploration (larger saccade amplitudes and shorter ﬁxation durations) for the Differentiation phase, and lower visual exploration (smaller saccades and longer ﬁxations) for the Consolidation phase. These results support that eye-movements can provide good indices of underlying processes occurring during a decision-making task in an everyday context.

Cognitive Processing

This study examined the links between attention, hand movements and eye movements when performed ... more This study examined the links between attention, hand movements and eye movements when performed in different spatial areas. Participants performed a visual search task on a computer screen while preparing to press two keyboard keys sequentially with their index. Results showed that the planning of the manual sequence influenced the latency of the first saccade and the placement of the first fixation. In particular, even if the first fixation placement was influenced by the combination of both components of the prepared manual sequence in some trials, it was affected principally by the first component of the prepared manual sequence. Moreover, the probability that the first fixation placement did reflect a combination of both components of the manual sequence was correlated with the speed of the second component. This finding suggests that the preparation of the second component of the sequence influence simultaneous oculomotor behavior when motor control of the manual sequence relied on proactive motor planning. These results are discussed taking into account the current debate on the eye/hand coordination research.

Most of studies about online advertisements have indicated that they have a negative impact on us... more Most of studies about online advertisements have indicated that they have a negative impact on users' cognitive processes, especially when they include colorful or animated banners and when they are close to the text to be read. In the present study we assessed the effects of two advertisements features-distance from the text and the animation-on visual strategies during a word-search task and a reading-for-comprehension task using Web-like pages. We hypothesized that the closer the advertisement was to the target text, the more cognitive processing difficulties it would cause. We also hypothesized that (1) animated banners would be more disruptive than static advertisements and (2) banners would have more effect on word-search performance than reading-for-comprehension performance. We used an automatic classifier to assess variations in use of Scanning and Reading visual strategies during task performance. The results showed that the effect of dynamic and static advertisements on visual strategies varies according to the task. Fixation duration indicated that the closest advertisements slowed down information processing but there was no difference between the intermediate (40 pixel) and far (80 pixel) distance conditions. Our findings suggest that advertisements have a negative impact on users' performance mostly when a lots of cognitive resources are required as for reading-for-comprehension.

We hypothesize that the fundamental difference between expert and learner musicians is the capaci... more We hypothesize that the fundamental difference between expert and learner musicians is the capacity to efficiently integrate cross-modal information. This capacity might be an index of an expert memory using both auditory and visual cues built during many years of learning and extensive practice. Investigating this issue through an eye-tracking experiment, two groups of musicians, experts and non-experts, were required to report whether a fragment of classical music, successively displayed both auditorily and visually on a computer screen (cross-modal presentation) was same or different. An accent mark, associated on a particular note, was located in a congruent or incongruent way according to musical harmony rules, during the auditory and reading phases. The cross-modal competence of experts was demonstrated by shorter fixation durations and less errors. Accent mark appeared for non-experts as interferences and lead to incorrect judgments. Results are discussed in terms of amodal memory for expert musicians that can be supported within the theoretical framework of Long-Term Working Memory .

The aim of this paper is to clarify the role played by referential factors in the development of ... more The aim of this paper is to clarify the role played by referential factors in the development of a spatial code during reading. Specifically, it explores whether this spatial encoding is determined by referential events related to a change in narrative mode which affect the integration process. Participants read narrative texts consisting of two paragraphs in which the point of view either changed or remained the same. The display mode was also manipulated (spatialized versus nonspatialized presentation). The results of experiment 1 (reading task) indicated that readers take more Keywords: Reading, spatial encoding, referential events. time to read text containing a change in point of view. Using a new methodology to assess spatial memory, experiments 2 (visual-search pointing task) and 3 (memory-search pointing task) showed that subjects are faster and more accurate at locating text areas where such perspective shifts occurred. It is proposed that spatial encoding is a strategic process optimizing potentials by backtracking to important parts of a text in order to solve referential difficulties occurring later in the text.

The mass digitization of books is changing the way information is created, disseminated and displ... more The mass digitization of books is changing the way information is created, disseminated and displayed. Electronic book readers (e-readers) generally refer to two main display technologies: the electronic ink (E-ink) and the liquid crystal display (LCD). Both technologies have advantages and disadvantages, but the question whether one or the other triggers less visual fatigue is still open. The aim of the present research was to study the effects of the display technology on visual fatigue. To this end, participants performed a longitudinal study in which two last generation e-readers (LCD, E-ink) and paper book were tested in three different prolonged reading sessions separated by -on average -ten days. Results from both objective (Blinks per second) and subjective (Visual Fatigue Scale) measures suggested that reading on the LCD (Kindle Fire HD) triggers higher visual fatigue with respect to both the E-ink (Kindle Paperwhite) and the paper book. The absence of differences between E-ink and paper suggests that, concerning visual fatigue, the E-ink is indeed very similar to the paper. Citation: Benedetto S, Drai-Zerbib V, Pedrotti M, Tissier G, Baccino T (2013) E-Readers and Visual Fatigue. PLoS ONE 8(12): e83676.

Recent research suggests that older Internet users seem to find it more difficult to locate navig... more Recent research suggests that older Internet users seem to find it more difficult to locate navigation links than to find information content in web pages. One possibility is that older Internet users' visual exploration of web pages is more linear in nature, even when this type of processing is not appropriate for the task. In the current study, the eye movements of young and older Internet users were recorded using an ecological version of the web pages or a discursive version designed to induce a linear exploration. The older adults found more targets when performing content-oriented compared to navigation-oriented searches, thus replicating previous results. Moreover, they performed less well than young people only when required to locate navigation links and tended to outperform the younger participants in content-oriented searches. Although the type of search task and type of web page resulted in different visual strategies, little or no support was found for the hypothesis that older participants explore web pages in a more linear way in cases where this strategy was not appropriate. The main conclusion is that differences in visual exploration do not seem to mediate the specific difficulty older adults experience in navigationoriented searches in web pages. (I. Etcheverry), baccino@ lutin-userlab.fr (T. Baccino), terrier@univ-tlse2.fr (P. Terrier), marquie@univ-tlse2.fr (J.-C. Marquié), mustapha.mojahid@irit.fr (M. Mojahid).

Overt visual attention is the act of directing the eyes toward a given area. These eye movements ... more Overt visual attention is the act of directing the eyes toward a given area. These eye movements are characterised by saccades and fixations. A debate currently surrounds the role of visual fixations. Do they all have the same role in the free viewing of natural scenes? Recent studies suggest that at least two types of visual fixations exist: focal and ambient. The former is believed to be used to inspect local areas accurately, whereas the latter is used to obtain the context of the scene. We investigated the use of an automated system to cluster visual fixations in two groups using four types of natural scene images. We found new evidence to support a focalambient dichotomy. Our data indicate that the determining factor is the saccade amplitude. The dependence on the low-level visual features and the time course of these two kinds of visual fixations were examined. Our results demonstrate that there is an interplay between both fixation populations and that focal fixations are more dependent on low-level visual features than are ambient fixations.

The extent to which so-called low-level features are relevant to predict gaze allocation has been... more The extent to which so-called low-level features are relevant to predict gaze allocation has been widely studied recently. However, the conclusions are contradictory. Edges and luminance contrasts seem to be always involved, but literature is conflicting about contribution of the different spatial scales. It appears that experiments using man-made scenes lead to the conclusion that fixation location can be efficiently discriminated using high-frequency information, whereas mid-or low frequencies are more discriminative for natural scenes. This paper focuses on the importance of spatial scale to predict visual attention. We propose a fast attentional model and study which frequency band predicts the best fixation locations during free-viewing task. An eye-tracking experiment has been conducted using different scene categories defined by their Fourier spectrums (Coast, Open-Country, Mountain, and Street). We found that medium frequencies (0.7-1.3 cycles per degree) globally allowed the best prediction of attention, with variability among categories. Fixation locations were found to be more predictable using medium to high frequencies in man-made street scenes and low to medium frequencies in natural landscape scenes.

Document foraging for information is a crucial and increasingly prevalent activity nowadays. We d... more Document foraging for information is a crucial and increasingly prevalent activity nowadays. We designed a computational cognitive model to simulate the oculomotor scanpath of an average web user searching for specific information from textual materials. In particular, the developed model dynamically combines visual, semantic, and memory processes to predict the user's focus of attention during information seeking from paragraphs of text. A series of psychological experiments was conducted using eye-tracking techniques in order to validate and refine the proposed model. Comparisons between model simulations and human data are reported and discussed taking into account the strengths and shortcomings of the model. The proposed model provides a unique contribution to the investigation of the cognitive processes involved during information search and bears significant implications for web page design and evaluation.

It is often said that experienced musicians are capable of hearing what they read (and vice versa... more It is often said that experienced musicians are capable of hearing what they read (and vice versa). This suggests that they are able to process and to integrate multimodal information. The present study investigates this issue with an eye-tracking technique. Two groups of musicians chosen on the basis of their level of expertise (experts, non-experts) had to read excerpts of poorly-known classical piano music and play them on a keyboard. The experiment was run in two consecutive phases during which each excerpt was (1) read without playing and (2) sight-read (read and played). In half the conditions, the participants heard the music before the reading phases. The excerpts contained suggested fingering of variable difficulty (difficult, easy, or no fingering). Analyses of first-pass fixation duration, second-pass fixation duration, probability of re-fixation, and playing mistakes validated the hypothesized modal independence of information among expert musicians as compared to non-experts. The results are discussed in terms of the processing cues and retrieval structures postulated by in their model of expert memory.

With the aim of studying attentional leftward bias in a driving context, we combined recording of... more With the aim of studying attentional leftward bias in a driving context, we combined recording of gaze behaviour with a simulated driving task (Lane Change Test -LCT) in spatial symmetry conditions. The LCT requires driving along a straight traffic-free three-lane road, changing lanes according to the information provided by two identical road signs displayed concurrently on both left and right sides of the road. Participants directed most of their attention to the left-hand signs. The prevalent visuospatial nature of the driving taskwhich is supposed to mostly activate the right cerebral hemisphere -could have caused a contralateral attention shift. The introduction of a secondary task -performed with the right hand, concurrently with the LCT -attenuated the leftward bias.

Revue d'Interaction Homme- …, 2005

Cognitive Processing