Early-onset binocularity in preterm infants reveals experience-dependent visual development in humans.
Proc Natl Acad Sci U S A
; 109(27): 11049-52, 2012 Jul 03.
Article
em En
| MEDLINE
| ID: mdl-22711824
ABSTRACT
Although there is a great deal of knowledge regarding the phylo- and ontogenetic plasticity of the neocortex, the precise nature of environmental impact on the newborn human brain is still one of the most controversial issues of neuroscience. The leading model-system of experience-dependent brain development is binocular vision, also called stereopsis. Here, we show that extra postnatal visual experience in preterm human neonates leads to a change in the developmental timing of binocular vision. The onset age of binocular function, as measured by the visual evoked response to dynamic random dot correlograms (DRDC-VEP), appears to be at around the same time after birth in preterm (4.07 mo) and full-term (3.78 mo) infants. To assess the integrity of the visual pathway in the studied infants, we also measured the latency of the visual-evoked response to pattern reversal stimuli (PR-VEP). PR-VEP latency is not affected by premature birth, demonstrating that the maturation of the visual pathway follows a preprogrammed developmental course. Despite the immaturity of the visual pathway, clearly demonstrated by the PR-VEP latencies, our DRCD-VEP data show that the visual cortex is remarkably ready to accept environmental stimulation right after birth. This early plasticity makes full use of the available extra stimulation time in preterm human infants and results in an early onset of cortical binocularity. According to our data, the developmental processes preceding the onset of binocular function are not preprogrammed, and the mechanisms turning on stereopsis are extremely experience-dependent in humans.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Córtex Visual
/
Recém-Nascido Prematuro
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Visão Binocular
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Percepção de Profundidade
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Plasticidade Neuronal
Limite:
Humans
/
Newborn
Idioma:
En
Ano de publicação:
2012
Tipo de documento:
Article