Ces deux études utilisent une même méthod e: celle du décodage de l'activité cérébrale par magnétoencéphalographie (MEG). Cette technique non-invasive permet de mesurer les champs magnétiques générés par l'activité neuronale dans le cortex : lorsque les neurones s’activent, les courants électriques génèrent instantanément des champs magnétiques.
Seeing in stereoscopic depth relies on the slight differences in the images in the two eyes resulting from their horizonal separation. As the inputs from the eyes are first combined in the primary visual cortex (V1), human brain imaging can be used to investigate the earliest stages of processing. To perceive depth, binocular neurons in V1 need balanced input from the two eyes, likely established by mutual inhibition, whereby activation of one eye inhibits the other eye. Thus, when input from the two eyes is comparable, both will contribute equally to binocular vision to promote 3D vision.
In the rare case that both eyes fail to develop, there is a complete absence of light input to the visual system at all stages of development. This raises the question of how the brain utilises the cortical and subcortical areas that would usually process visual information. It has been shown in a number of studies that the ‘visual cortex’ of congenitally blind people is used to process ‘high-level’ auditory information such as language. In this talk I will present a series of fMRI studies in which we attempt to understand how auditory information reaches the occipital lobe.
While damage to the primary visual cortex, often due to a stroke, leads to loss of the visual field contralateral to the damaged cortex, there are currently few opportunities for rehabilitation. In my previous talk I laid out how we have used multi-modal MRI to uncover the pathways likely to be carrying visual information after damage to primary visual cortex. The aim of this talk, therefore, is to consider the effects of visual training on both behavioural and neural structures.
Damage to the primary visual cortex leads to loss of the visual field contralateral to the damaged cortex. However, in spite of this loss, some patients are still able to detect visual information about stimuli presented within their blind field. A growing area of research aims to exploit this residual visual function to try to improve visual performance through rehabilitation programmes stimulating the blind field. However, to optimise such programmes it is important to understand the pathways through which this information is conveyed.
This project is funded by the Fondation Pour l'Audition.
To find out more, read the article on the Fondation Pour l'Audition website.
Newborns have very limited vision. Yet they are already learning to see. We discovered this when we took advantage of a natural experiment: children born with dense cataracts in one or both eyes that blocked all patterned visual input until the cataracts were removed during infancy and the eyes given compensatory contact lenses. Even when the babies missed only a few months of visual input, they later developed a host of deficits in both low-level (e.g., acuity, peripheral vision), and high-level (e.g., perceiving the direction of motion, face processing) vision.
This pluridisciplinary workshop aimed at reflecting on the possibility of moving behavioral, neuroscientific, computational and clinical hearing sciences towards the study of the human auditory system's ability to perceive the ecological processes at work in natural habitats using the tools, data, concepts and theories offered by modern ecoacoustics.
Abstract: It’s widely thought that metacognitive processes monitor and represent the uncertainty in different parts of the mind and brain, enabling sophisticated forms of cognitive and behavioural control. However, theoretical models have recently stressed that metacognition and uncertainty aren’t the same thing – and there may be a variety of representations about uncertainty or ‘precision’ throughout our perceptual and cognitive systems that are separate from those involved in subjective metacognition and conscious reflection.
