Dominance oculaire : implications neurophysiologiques et conséquences au niveau de la visuo-motricité - Aix-Marseille Université Access content directly
Theses Year : 2015

Eye dominance: neurophysiological implications and visuo-motor consequences

Dominance oculaire : implications neurophysiologiques et conséquences au niveau de la visuo-motricité

Abstract

Processing of visual information from the environment is preponderant for the successful performance of many motor behaviors. Although there exists a vast amount of literature devoted to the understanding of the neurophysiology, the neuroanatomy and behavioral aspects of the visual and visuo-motor systems, one important issue that is not well understood, and poorly studied, is the role of eye dominance (ED). ED corresponds to a lateralization of the visual system. In the framework of our thesis, we were particularly interested in examining the sighting eye dominance which defines the dominant eye (DE) as the one we unconsciously choose when performing monocular tasks. Recently, a neurophysiological basis for ED was proposed which stated that the DE and its ipsilateral hemisphere (connected via the temporal hemiretina) may have a special relationship. The purpose of our thesis was to test the behavioral and neurophysiological consequences of this relationship by examining the influence of ED on the integration of visual information and more specifically when they are used during movement. By selecting participants according to their dominant eye, and varying the side of the stimulated visual hemifield, we show that during simple manual reaction time tasks (Article I), and more complex manual reaching movements (supplementary data I), the targets presented in the contralateral hemifield with respect to the DE (i.e. which stimulate the temporal hemiretina of the DE) receive a temporal advantage. Furthermore, during vertical saccadic eye movements, the presentation of a distractor in the contralateral hemifield causes a larger deviation of the saccade trajectory compared to the presentation of a distractor in the ipsilateral hemifield (Article II). Thus, these results indicate that the influence of the ED on the visuo-motor transformations involved in manual movements extends to the production of eye movements. To gain further insight into the mechanisms which could underpin the influence of ED, we used the electroencephalography (EEG) to measure cortical responses during a fundamental process of the human visuo-motor transformations: the interhemispheric communication. The results of this study revealed that the interhemispheric transfer time of visual information strictly depends on the ED (Article III). We also demonstrate that the influence of ED acts at the level of attentional processes as we observe a modulation of the ED on the amount of pseudoneglect in a line bisection task (supplementary data III). Finally, a part of our work, aiming at evaluate a quantification method of the ED, is directly transferable to the field of clinical neuro-ophtalmology (Article IV and supplementary data II). The current preoperative protocols would benefit from such a quantification measure and this will be valuable to the practitioner for certain surgical techniques (e.g. monovision technique). In sum, our work demonstrates that eye dominance has a widespread influence into different levels of visuo-motor transformations and interacts with other lateralizations of the central nervous system such as the manual lateralization and the lateralization of attentional networks. We also bring elements promoting a functional nature of the ED rather than a fixed anatomo-structural nature. In our view, ED is an important aspect of the human brain lateralization which has been overlooked up to now.
Les informations visuelles sont prépondérantes pour guider le comportement. Malgré une bonne connaissance du système visuel, un phénomène représentant une latéralisation de celui-ci, le phénomène de dominance oculaire (DO), reste mal compris et finalement peu étudié. Nos travaux de thèse ont permis de démontrer que cette DO exerce une large influence sur différentes étapes de la transformation des informations visuelles en mouvements manuels ou oculaires et que celle-ci s’exprime en interaction avec d’autres latéralisations du système nerveux telles que les latéralisations manuelle et des réseaux attentionnels. Nous montrons également son influence sur les processus de transfert d’information entre les deux hémisphères du cerveau. Enfin, nos travaux comportent des retombées cliniques directes : ils introduisent une méthode de quantification plus précise de la DO utilisable par les cliniciens pour une meilleure réussite de certaines techniques chirurgicales. En conclusion, nous montrons que la DO constitue un aspect important de la latéralisation du cerveau humain, relativement négligé jusqu’à présent.

Domains

Neuroscience
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Dates and versions

tel-01446683 , version 1 (20-02-2017)

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  • HAL Id : tel-01446683 , version 1

Cite

Romain Chaumillon. Dominance oculaire : implications neurophysiologiques et conséquences au niveau de la visuo-motricité. Neurosciences. Aix Marseille Université, 2015. Français. ⟨NNT : ⟩. ⟨tel-01446683⟩
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