Changes in occipital cortex activity in early blind humans using a sensory substitution device

Volder, Anne De; Catalan-Ahumada, Mitzi; Robert, Annie; Bol, Anne; Labar, Daniel; Coppens, A.; Michel, Christian; Veraart, Claude

doi:10.1016/s0006-8993(99)01275-5

Cited by 90 publications

(62 citation statements)

References 24 publications

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“…This is in agreement with previous neuroimaging studies showing an activation of this region during auditory spatial tasks in EB (Arno et al 2001;De Volder et al 1999;Leclerc et al 2000;Poirier et al 2006;Vanlierde et al 2003;Weeks et al 2000). The present TMS results thus provide further evidence that the right dorsal extrastriate occipital cortex is part of the brain network responsible for auditory spatial processing in EB (Collignon et al 2007;Collignon et al 2008b).…”

Section: Discussionsupporting

confidence: 93%

“…In line with these behavioural studies, functional neuroimaging experiments showed a profound reorganisation of the brain network dedicated to the processing of the spatial attributes of sounds in blind subjects. In particular, several positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) studies have demonstrated an increased activation in occipital areas during auditory spatial processing in EB (Arno et al 2001;De Volder et al 1999;Gougoux et al 2005;Leclerc et al 2000;Poirier et al 2006;Voss et al 2008). Moreover, it has been suggested that the recruitment of these visual areas deprived of their normal inputs may explain the exceptional abilities of EB in performing auditory spatial tasks (Gougoux et al 2005).…”

Section: Introductionmentioning

confidence: 99%

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Reorganisation of the Right Occipito-Parietal Stream for Auditory Spatial Processing in Early Blind Humans. A Transcranial Magnetic Stimulation Study

et al. 2009

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It is well known that, following an early visual deprivation, the neural network involved in processing auditory spatial information undergoes a profound reorganization. In particular, several studies have demonstrated an extensive activation of occipital brain areas, usually regarded as essentially "visual", when early blind subjects (EB) performed a task that requires spatial processing of sounds. However, little is known about the possible consequences of the activation of occipitals area on the function of the large cortical network known, in sighted subjects, to be involved in the processing of auditory spatial information. To address this issue, we used event-related transcranial magnetic stimulation (TMS) to induce virtual lesions of either the right intra-parietal sulcus (rIPS) or the right dorsal extrastriate occipital cortex (rOC) at different delays in EB subjects performing a sound lateralization task. Surprisingly, TMS applied over rIPS, a region critically involved in the spatial processing of sound in sighted subjects, had no influence on the task performance in EB. In contrast, TMS applied over rOC 50 ms after sound onset, disrupted the spatial processing of sounds originating from the contralateral hemifield. The present study shed new lights on the reorganisation of the cortical network dedicated to the spatial processing of sounds in EB by showing an early contribution of rOC and a lesser involvement of rIPS.

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Section: Discussionsupporting

confidence: 93%

Section: Introductionmentioning

confidence: 99%

Reorganisation of the Right Occipito-Parietal Stream for Auditory Spatial Processing in Early Blind Humans. A Transcranial Magnetic Stimulation Study

et al. 2009

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“…In addition, a number of devices can transduce visual data into sound (echolocation), electrotactile stimulation of the skin, or electrical stimulation of the tongue. In the case of blind individuals, extended use of these devices stimulates neuronal activity within the visual cortex of the patient even though these 'visual' data are delivered through decidedly non-visual pathways (Bach-y-Rita et al, 1969;De Volder et al, 1999;Bachy-Rita and Kercel, 2003;Ptito et al, 2005). However, the devices used in these studies make use of other existing sensory structures; how the brain responds to exogenous visual information delivered through additional novel structures and pathways remains unclear.…”

Section: Introductionmentioning

confidence: 99%

Ectopic eyes outside the head inXenopustadpoles provide sensory data for light-mediated learning

Blackiston

Levin

2013

Journal of Experimental Biology

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SUMMARYA major roadblock in the biomedical treatment of human sensory disorders, including blindness, has been an incomplete understanding of the nervous system and its ability to adapt to changes in sensory modality. Likewise, fundamental insight into the evolvability of complex functional anatomies requires understanding brain plasticity and the interaction between the nervous system and body architecture. While advances have been made in the generation of artificial and biological replacement components, the brainʼs ability to interpret sensory information arising from ectopic locations is not well understood. We report the use of eye primordia grafts to create ectopic eyes along the body axis of Xenopus tadpoles. These eyes are morphologically identical to native eyes and can be induced at caudal locations. Cell labeling studies reveal that eyes created in the tail send projections to the stomach and trunk. To assess function we performed light-mediated learning assays using an automated machine vision and environmental control system. The results demonstrate that ectopic eyes in the tail of Xenopus tadpoles could confer vision to the host. Thus ectopic visual organs were functional even when present at posterior locations. These data and protocols demonstrate the ability of vertebrate brains to interpret sensory input from ectopic structures and incorporate them into adaptive behavioral programs. This tractable new model for understanding the robust plasticity of the central nervous system has significant implications for regenerative medicine and sensory augmentation technology.

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“…For example, functional magnetic resonance imaging (fMRI) and positron emission tomography studies have established that medial occipital areas respond to a variety of stimuli and tasks (Sadato et al, 1998;De Volder et al, 1999;Weeks et al, 2000;Arno et al, 2001;Röder et al, 2002;Amedi et al, 2003;Burton, 2003;Burton et al, 2004;Gougoux et al, 2005;Poirier et al, 2005;Collignon et al, 2006). Indeed, the function of the "visual cortex" in early onset blindness remains speculative, precisely because it responds to so many different stimuli and tasks.…”

Section: Introductionmentioning

confidence: 99%

Preparatory Activity in Occipital Cortex in Early Blind Humans Predicts Auditory Perceptual Performance

Stevens¹,

Snodgrass²,

Schwartz³

et al. 2007

J. Neurosci.

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Early onset blindness leads to a dramatic alteration in the way the world is perceived, a change that is detectable in the organization of the brain. Several studies have confirmed that blindness leads to functional alterations in occipital cortices that normally serve visual functions. These reorganized brain regions respond to a variety of tasks and stimuli, but their specific functions are unclear. In sighted individuals, several studies have reported preparatory activity in retinotopic areas, which enhances perceptual sensitivity. "Baseline shifts," changes in activity associated with a cue predicting an upcoming event, provides a marker for attentional modulation. Here we demonstrate that, in early blind subjects, medial occipital areas produced significant blood oxygenation level-dependent (BOLD) responses to a cue signaling an auditory discrimination trial but not to a cue indicating a no-trial period. Furthermore, the amplitude of the BOLD response in the anterior calcarine sulcus of early blind subjects correlated with their discrimination performance on the auditory backward masking task. Preparatory BOLD responses also were present in auditory cortices, although they were more robust in blind than sighted control subjects. The pattern of response in visual areas is similar to preparatory effects observed during visual selective attention in sighted subjects and consistent with the hypothesis that the mechanisms implicated in visual attention continue to modulate occipital cortex in the early blind. A possible source of this top-down modulation may be the frontoparietal circuits that retain their connectivity with the reorganized occipital cortex and as a result influence processing of nonvisual stimuli in the blind.

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Changes in occipital cortex activity in early blind humans using a sensory substitution device

Cited by 90 publications

References 24 publications

Reorganisation of the Right Occipito-Parietal Stream for Auditory Spatial Processing in Early Blind Humans. A Transcranial Magnetic Stimulation Study

Reorganisation of the Right Occipito-Parietal Stream for Auditory Spatial Processing in Early Blind Humans. A Transcranial Magnetic Stimulation Study

Ectopic eyes outside the head inXenopustadpoles provide sensory data for light-mediated learning

Preparatory Activity in Occipital Cortex in Early Blind Humans Predicts Auditory Perceptual Performance

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