Population receptive field and connectivity properties of the early visual cortex in human albinism.
Neuroimage
; 202: 116105, 2019 11 15.
Article
in En
| MEDLINE
| ID: mdl-31422172
ABSTRACT
In albinism, the pathological decussation of the temporal retinal afferents at the optic chiasm leads to superimposed representations of opposing hemifields in the visual cortex. Here, we assessed the equivalence of the two representations and the cortico-cortical connectivity of the early visual areas. Applying fMRI-based population receptive field (pRF)-mapping (both hemifield and bilateral mapping) and connective field (CF)-modeling, we investigated the early visual cortex in 6 albinotic participants and 4 controls. In albinism, superimposed retinotopic representations of the contra- and ipsilateral visual hemifield were observed on the hemisphere contralateral to the stimulated eye. This was confirmed by the observation of bilateral pRFs during bilateral mapping. Hemifield mapping revealed similar pRF-sizes for both hemifield representations throughout V1 to V3. The typical increase of V1-sampling extent for V3 compared to V2 was not found for the albinotic participants. The similarity of the pRF-sizes for opposing visual hemifield representations highlights the equivalence of the two maps in the early visual cortex. The altered V1-sampling extent in V3 might indicate the adaptation of cortico-cortical connections to visual pathway abnormalities in albinism. These findings thus suggest that conservative developmental mechanisms are complemented by alterations of the extrastriate cortico-cortical connectivity.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Visual Cortex
/
Visual Pathways
/
Albinism
Type of study:
Prognostic_studies
Limits:
Adolescent
/
Adult
/
Female
/
Humans
/
Male
/
Middle aged
Language:
En
Journal:
Neuroimage
Journal subject:
DIAGNOSTICO POR IMAGEM
Year:
2019
Type:
Article
Affiliation country:
Germany