Imperial College London
Alternate

DrInesRibeiro Violante

Faculty of Medicine, Department of Brain Sciences

Honorary Research Fellow
 
 
 
//

Contact

 

+44 (0)20 7594 7994i.violante

 
 
//

Location

 

Burlington DanesHammersmith Campus

//

Summary

 

Publications

Citation

BibTex format

@article{Violante:2012:10.1371/journal.pone.0038785,
author = {Violante, IR and Ribeiro, MJ and Cunha, G and Bernardino, I and Duarte, JV and Ramos, F and Saraiva, J and Silva, E and Castelo-Branco, M},
doi = {10.1371/journal.pone.0038785},
journal = {PLOS One},
title = {Abnormal brain activation in neurofibromatosis type 1: a link between visual processing and the default mode network.},
url = {http://dx.doi.org/10.1371/journal.pone.0038785},
volume = {7},
year = {2012}
}
Download

RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Neurofibromatosis type 1 (NF1) is one of the most common single gene disorders affecting the human nervous system with a high incidence of cognitive deficits, particularly visuospatial. Nevertheless, neurophysiological alterations in low-level visual processing that could be relevant to explain the cognitive phenotype are poorly understood. Here we used functional magnetic resonance imaging (fMRI) to study early cortical visual pathways in children and adults with NF1. We employed two distinct stimulus types differing in contrast and spatial and temporal frequencies to evoke relatively different activation of the magnocellular (M) and parvocellular (P) pathways. Hemodynamic responses were investigated in retinotopically-defined regions V1, V2 and V3 and then over the acquired cortical volume. Relative to matched control subjects, patients with NF1 showed deficient activation of the low-level visual cortex to both stimulus types. Importantly, this finding was observed for children and adults with NF1, indicating that low-level visual processing deficits do not ameliorate with age. Moreover, only during M-biased stimulation patients with NF1 failed to deactivate or even activated anterior and posterior midline regions of the default mode network. The observation that the magnocellular visual pathway is impaired in NF1 in early visual processing and is specifically associated with a deficient deactivation of the default mode network may provide a neural explanation for high-order cognitive deficits present in NF1, particularly visuospatial and attentional. A link between magnocellular and default mode network processing may generalize to neuropsychiatric disorders where such deficits have been separately identified.
AU  - Violante,IR
AU  - Ribeiro,MJ
AU  - Cunha,G
AU  - Bernardino,I
AU  - Duarte,JV
AU  - Ramos,F
AU  - Saraiva,J
AU  - Silva,E
AU  - Castelo-Branco,M
DO  - 10.1371/journal.pone.0038785
PY  - 2012///
SN  - 1932-6203
TI  - Abnormal brain activation in neurofibromatosis type 1: a link between visual processing and the default mode network.
T2  - PLOS One
UR  - http://dx.doi.org/10.1371/journal.pone.0038785
UR  - http://hdl.handle.net/10044/1/29365
VL  - 7
ER  -
Download