Jean-Luc Velay - Profile on Academia.edu (original) (raw)

Papers by Jean-Luc Velay

Chapitre 13. Apprendre à écrire les lettres pour mieux les reconnaître

Éditions de la Maison des sciences de l’homme eBooks, Jul 3, 2017

Recognizing the letters encountered when reading is generally assumed to be a purely visual proce... more Recognizing the letters encountered when reading is generally assumed to be a purely visual process, yet a large body of data supports the view that movement plays a crucial role in letter representation and suggests that handwriting contributes to the visual recognition of letters. We established that simply viewing letters activated a part of the left premotor cortex that was also activated when the letters were being written by the subjects. These results, which were confirmed in left-hander subjects, indicate that writing motor processes are implicitly evoked when passively observing letters. The cerebral representation of letters is therefore presumably not strictly visual, but based on a multicomponent neural network built up while learning concomitantly to read and write. If so, changing the motor conditions while children are learning to write by using a method based on typing instead of handwriting should affect their subsequent letter recognition performances. In order to test this hypothesis, we trained two groups of 38 children to copy letters of the alphabet either by hand or by typing them. After three weeks of learning, in the older children, the handwriting training gave rise to a better letter recognition than the typing training. These findings show the existence of close functional relations between the reading and writing processes, and suggests that our reading abilities might be somehow dependent on the way we write

Vision Research, Sep 1, 1997

Previous studies have shown that low amplitude/high frequency mechanical vibration applied to the... more Previous studies have shown that low amplitude/high frequency mechanical vibration applied to the human eye muscles results in the illusory movement of a luminous spot fixated in total darkness. The aim of the present study was to investigate whether a vibration-induced motor response also occurs in eye nmsdes, and to check whether the visual illusions actually result from the proprioceptors being activated by the vibration, or whether they are simply due to the retinal slip induced by the reflex eye movement. The effects of the vibratory stimuli on the inferior rectus (IR) and lateral rectus (LR) muscles were evaluated by recording subjects' eye position changes. When applied to the IR muscle, vibration effectively elicited an upward visual illusion accompanied by a small downward ocular rotation, whereas when applied to the LR muscle, it also induced horizontal visual illusion, which was less frequent and weaker than the vertical one, but no ocular rotation. We concluded that visual illusions of this kind cannot be attributable to the retinal motion of the image of the fixated point. The difference between the vertical and horizontal vibratory motor responses is discussed as regards the particular role that oculo-muscular proprioception may play in the vertical muscles.

HAL (Le Centre pour la Communication Scientifique Directe), 2012

Nowadays, computer aided design (CAD) is widely used by designers. Would children learn to draw m... more Nowadays, computer aided design (CAD) is widely used by designers. Would children learn to draw more easily and more efficiently if they were taught with computerised tools? To answer this question, we made an experiment designed to compare two methods for children to do the same drawing: the classical 'pen and paper' method and a CAD method. We asked two groups of 14 children to draw a geometrical figure: the Rey-Osterrieth Complex Figure (ROCF). The first group drew it with a pen on a sheet of paper ('paper' group) and the second on a computer screen with CAD software ('computer' group). Two drawing conditions were studied: 'Copying' the figure and drawing from memory. Results showed that the 'computer' group was better at copying the figure but that both groups performed equally well when the figure was drawn from memory. These preliminary results suggest that using a CAD tool could help children while they copy a model, but that it does not improve their ability to draw the same figure using their own, internal model.

Contribution of Skeletal and Extraocular Proprioception to Kinaesthetic Representation

Psychologie Francaise, Jun 1, 2010

Rec ¸u le 14 décembre 2009 ; accepté le 2 mars 2010 La capacité à reconnaître les lettres, pierre... more Rec ¸u le 14 décembre 2009 ; accepté le 2 mars 2010 La capacité à reconnaître les lettres, pierre angulaire de la lecture, est traditionnellement considérée comme reposant uniquement sur des processus visuels. Pourtant, comme beaucoup des objets qui nous entourent, les lettres sont apprises par une mise en correspondance entre une configuration visuelle et des mouvements. Nous présentons une revue des arguments suggérant que les caractéristiques des mouvements d'écriture influencent la reconnaissance visuelle des lettres, à la fois au plan comportemental et au plan des réseaux cérébraux mis en jeu. L'un des attributs des lettres dont la reconnaissance pourrait être la plus dépendante de la motricité est leur orientation.

Human Movement Science, Aug 1, 2015

The aim of the present study was to analyze handwriting difficulties in children with development... more The aim of the present study was to analyze handwriting difficulties in children with developmental coordination disorder (DCD) and investigate the hypothesis that a deficit in procedural learning could help to explain them. The experimental setup was designed to compare the performances of children with DCD with those of a non-DCD group on tasks that rely on motor learning in different ways, namely handwriting and learning a new letter. Ten children with DCD and 10 non-DCD children, aged 8-10 years, were asked to perform handwriting tasks (letter/word/sentence; normal/fast), and a learning task (new letter) on a graphic tablet. The BHK concise assessment scale for children's handwriting was used to evaluate their handwriting quality. Results showed that both the handwriting and learning tasks differentiated between the groups. Furthermore, when speed or length constraints were added, handwriting was more impaired in children with DCD than in non-DCD children. Greater intra-individual variability was observed in the group of children with DCD, arguing in favor of a deficit in motor pattern stabilization. The results of this study could support both the hypothesis of a deficit in procedural learning and the hypothesis of neuromotor noise in DCD.

Interhemispheric relationship in 4- to 14-years-old children pointing to lateral targets

HAL (Le Centre pour la Communication Scientifique Directe), 2003

Effects of Different Postural Conditions on Handwriting Variability

Journal of forensic document examination, 2011

During their career, forensic document examiners will inevitably be confronted with handwriting c... more During their career, forensic document examiners will inevitably be confronted with handwriting carried out under unusual conditions (UnC). A questioned document signed on top of a car or on a vertical surface like a wall are two examples. These atypical circumstances may give rise to more variability of the signatures or written words, in particular if the body was in non-traditional writing position without the traditional support. Few studies were devoted to handwriting variability under unusual writing conditions. The current study investigates whether individual variability changes with special writing conditions. In a previous study (Sciacca & al, 2009), we found that eight repetitions were sufficient to obtain a correct estimation of the variance. In the present study, twelve subjects were asked to write two word sets eight times in upper and eight times in lower case, under different conditions : sitting and writing on a horizontal (usual condition UC) or vertical support; and standing, kneeling or laying while writing on a horizontal or vertical support (unusual conditions UnC). Words were written on a pen tablet, normalized in space and time and then averaged. The variance of the eight words was measured under all conditions. Results showed only an increase in variability under the laying and kneeling / vertical UnC. Within the five other postural conditions tested, handwriting was shown to be very stable.

Proprioception as a link between body space and extra-personal space

Abstract 1. put forward some experimental arguments supporting the assumption that whole-body, sp... more Abstract 1. put forward some experimental arguments supporting the assumption that whole-body, spatially oriented behaviour might be based on a body reference frame which results mainly from the common processing of various sensory feedbacks arising in the muscles ...

Shift in saccadic direction induced in humans by proprioceptive manipulation: a comparison between memory-guided and visually guided saccades

Experimental Brain Research, Aug 1, 1996

... a comparison between memory-guided and visually guided saccades ... Here we attempted to chan... more ... a comparison between memory-guided and visually guided saccades ... Here we attempted to change the initial eye position signal supplied to the oculomotor system before a memory-or visuo-guided saccade to a 10 left target by applying mechanical vibration to the IR muscle. ...

Human Movement Science, Apr 1, 1989

Neuropsychologia, 2005

In a previous fMRI study on right-handers (Rhrs), we reported that part of the left ventral premo... more In a previous fMRI study on right-handers (Rhrs), we reported that part of the left ventral premotor cortex (BA6) was activated when alphabetical characters were passively observed and that the same region was also involved in handwriting [

Eye and neck proprioceptive messages contribute to the spatial coding of retinal input in visually oriented activities

Experimental Brain Research, Jun 1, 1991

The egocentric localization of objects in extrapersonal space requires that the retinal and extra... more The egocentric localization of objects in extrapersonal space requires that the retinal and extraretinal signals specifying the gaze direction be simultaneously processed. The question as to whether the extraretinal signal is of central or peripheral origin is still a matter of controversy, however. Three experiments were carried out to investigate the following hypotheses: 1) that the proprioceptive feedback originating in eye and neck muscles might provide the CNS with some indication about the gaze direction; and 2) that the retinal and proprioceptive extraretinal inputs might be jointly processed depending on whether they are of monocular or binocular origin. Application of low amplitude mechanical vibrations to either the extraocular or neck muscles (or both) of a subject looking monocularly at a small luminous target in darkness resulted in an illusory movement of the target, the direction of which depended on which muscle was stimulated. A slow upward target displacement occurred on vibrating the eye inferior rectus or the neck sterno-cleido-mastoidus muscles, whereas a downward shift was induced when the dorsal neck muscles (trapezius and splenius) were vibrated. The extent of the perceptual effects reported by subjects was measured in an open-loop pointing task in which they were asked to point at the perceived position of the target. These results extend to visually-oriented behavior the role of extraocular and neck proprioceptive inputs previously described in the case of postural regulation, since they clearly show that these messages contribute to specifying the gaze direction. This suggests that the extraretinal signal might include a proprioceptive component.(ABSTRACT TRUNCATED AT 250 WORDS)

NeuroImage, Aug 1, 2003

In the present fMRI study, we addressed the question as to whether motor-perceptual interactions ... more In the present fMRI study, we addressed the question as to whether motor-perceptual interactions might be involved in reading. Recognizing the letters encountered when reading is generally assumed to be a purely visual process, yet because we know how to write, we also possess a sensorimotor representation of the letters. Does simply viewing a letter suffice to activate the corresponding motor representation? To answer this question, we asked right-handed subjects first to look at and then to copy single letters or pseudoletters. We established that the visual presentation of letters activated a part of the left premotor cortex (BA6) that was also activated when the letters were being written by the subjects. This premotor zone resembles Exner's area, which is thought to contain the motor programs necessary for producing letters. Visually presented pseudoletters, which had never been written before by the subjects, did not activate this region. These results indicate that the writing motor processes are implicitly evoked when passively observing letters. The cerebral representation of letters is therefore presumably not strictly visual, but based on a multicomponent neural network built up while learning concomitantly to read and write. One of the components might be a sensorimotor one associated with handwriting. This finding shows the existence of close functional relations between the reading and writing processes, and suggests that our reading abilities might be somehow dependent on the way we write.

We investigated the combined effects of orthographic and graphomotor constraints as a function of... more We investigated the combined effects of orthographic and graphomotor constraints as a function of handwriting proficiency in children. Twenty-four first graders, 20 third graders, and 21 fifth graders wrote single five-letter words in cursive writing on a sheet of paper affixed to a digitizing tablet. The words were chosen according to two orthographic constraints, namely their lexical frequency and the graphemic complexity of the last three letters, and one graphomotor constraint resulting from the motor difficulty of tracing the first letter. In addition to massive improvements of handwriting with grade, the results revealed, in the youngest group only, an interaction between first-letter difficulty and lexical frequency. This finding suggests that, before handwriting movement becomes automated, the cognitive resources needed for retrieving word spelling interferes with motor processing while writing a difficult letter. When students start learning to write, they are particularly sensitive to the combination of orthographic and graphomotor constraints.

Étudier Les Phénomènes Émotionnels en Classe : Au Carrefour Des Neurosciences et Des Recherches en Éducation

Éducation et socialisation, Sep 10, 2018

Pour faire progresser les recherches en education centrees tout particulierement sur les thematiq... more Pour faire progresser les recherches en education centrees tout particulierement sur les thematiques complexes telles que l’influence des emotions sur les apprentissages en classe, la collaboration entre les Sciences de l’Education et les Neurosciences se revele la demarche la plus pertinente. Cependant de telles recherches interdisciplinaires sont semees d’embuches et d’obstacles divers. Cela est du en partie aux interactions des approches theoriques et methodologiques des deux disciplines, mais egalement au caractere multidimensionnel de la situation experimentale en milieu scolaire ainsi qu’au phenomene complexe qu’est l’emotion elle-meme. Nous revenons ici sur les difficultes d’une etude experimentale en milieu scolaire et proposons des reflexions pour surmonter ces obstacles afin de faire progresser les connaissances sur l’apprentissage scolaire, et par consequent les pratiques educatives.

Neuropsychologia, Jul 1, 1999

The purpose of this study was to explore the intrahemispheric processes and the interhemispheric ... more The purpose of this study was to explore the intrahemispheric processes and the interhemispheric transfer that occur during the programming of a pointing movement[ Twenty _ve subjects participated in this experiment] 01 were right!handed "Rhr#\ 01 left! handed "Lhr#\ and 0 was left!handed with a posterior callosal lesion[ The task consisted in producing an open loop pointing response toward a visual target appearing brie~y on the right or the left of a central _xation point[ Reaction times "RTs# were shorter for the Rhrs when reaching with the left hand than with the right hand[ No such hand!related di}erence was observed in the Lhrs[ The left hand advantage indicates that one process was faster in the right hemisphere of Rhrs[ This faster process appears not to be visual but motor or visuomotor[ For either hand\ responses were faster when the target appeared in the visual _eld homolateral to the pointing hand "uncrossed condition# than when it appeared contralaterally to the hand "crossed condition#[ The crossed vs uncrossed di}erence did not vary between Rhrs and Lhrs or between the hands[ The transfer time between the hemispheres was symmetrical whatever its direction[ The partially callosotomized left!handed subject was two!fold slower than the control Lhrs[ His uncrossed responses were faster than the crossed ones\ but his interhemispheric transfer time was very asymmetrical] it was normal from right to left hemisphere but was highly increased in the opposite direction[ An attempt at modelling the RT data is proposed and the possibility of di}erent callosal locations for the interhemispheric transfer is discussed[ Þ 0888 Elsevier Science Ltd[ All rights reserved[

Proprioceptive Control of Goal-Directed Movements in Man, Studied by Means of Vibratory Muscle Tendon Stimulation

Journal of Motor Behavior, Jun 1, 1991

The purpose of this study was to investigate the role of propriomuscular feedback in the control ... more The purpose of this study was to investigate the role of propriomuscular feedback in the control of pluriarticular pointing movements, performed without visual feedback toward visual targets. The proprioceptive inputs were distorted during movements by applying vibration to the distal tendon of the biceps muscle. Various movement and vibration durations were imposed. The results show that vibration affects the spatial outcome of the movements. The effects of vibration were movement time-independent when the durations were shorter than 450 ms and became movement time-dependent with longer durations. Moreover, the effects of vibration became more marked when a short vibration was applied at the end rather than at the beginning of a slow movement. These studies suggest that at least two types of proprioceptive control loops may be involved in correcting this kind of movement, depending on the execution time. In slow movements, the final phase might be a privileged period for on-line, propriomuscular-based corrections. Lastly, it emerged that the regulation of a goal-directed movement on the basis of proprioceptive feedback processing can take place within at most 200 ms.

Développements, Apr 1, 2013

Trends in Neuroscience and Education, Sep 1, 2016