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Low-level visual cortex and motion perception: an MRI study

Nicolas Wotawa 1
1 ODYSSEE - Computer and biological vision
DI-ENS - Département d'informatique de l'École normale supérieure, CRISAM - Inria Sophia Antipolis - Méditerranée , ENS Paris - École normale supérieure - Paris, Inria Paris-Rocquencourt, ENPC - École des Ponts ParisTech
Abstract : The evolution of cerebral imaging technologies combined with specific image processing algorithms contribute to improving our knowledge of the brain functioning, in particular regarding visual perception. This thesis contributes to current understanding implied in visual motion perception in humans, based on complementary information brought by different Magnetic Resonance Imaging (MRI) modalities.

The first part of this work focuses on functional MRI (fMRI) identification of low-level visual areas. We detail the fMRI retinotopic mapping procedure we developed, from the stimulus design to the final anatomo-functional analysis. A specific functional localization of the hMT/V5+ complex is also obtained with a block design. These methods, optimized according to some stimulation parameters, allow the extraction of individually defined and homogeneous Regions Of Interest (ROI).

In the second part, we characterize functionally these previously identified low-level visual areas. Based on the recent fMR-Adaptation paradigm, which allows to investigate the sensitivity of a cortical region to quantitative variations of a given feature, we demonstrate a functional differentiation across areas regarding their relative sensitivity to visual direction of motion.

Lastly, we combine fMRI and Diffusion Tensor MRI (DTI) to study the anatomical connectivity within the low-level visual cortex. Based on state of the art white matter fibers mapping algorithms, this characterization gives insights on the network of areas implied, among others, in visual motion processing.
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https://tel.archives-ouvertes.fr/tel-00071516
Contributor : Nicolas Wotawa <>
Submitted on : Tuesday, May 23, 2006 - 5:49:03 PM
Last modification on : Thursday, October 29, 2020 - 3:01:39 PM
Long-term archiving on: : Sunday, April 4, 2010 - 10:21:40 PM

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  • HAL Id : tel-00071516, version 1

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Nicolas Wotawa. Low-level visual cortex and motion perception: an MRI study. Neurons and Cognition [q-bio.NC]. Université Nice Sophia Antipolis, 2006. English. ⟨tel-00071516⟩

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