Early category-specific cortical activation revealed by visual stimulus inversion.
PLoS One
; 3(10): e3503, 2008.
Article
en En
| MEDLINE
| ID: mdl-18946504
Visual categorization may already start within the first 100-ms after stimulus onset, in contrast with the long-held view that during this early stage all complex stimuli are processed equally and that category-specific cortical activation occurs only at later stages. The neural basis of this proposed early stage of high-level analysis is however poorly understood. To address this question we used magnetoencephalography and anatomically-constrained distributed source modeling to monitor brain activity with millisecond-resolution while subjects performed an orientation task on the upright and upside-down presented images of three different stimulus categories: faces, houses and bodies. Significant inversion effects were found for all three stimulus categories between 70-100-ms after picture onset with a highly category-specific cortical distribution. Differential responses between upright and inverted faces were found in well-established face-selective areas of the inferior occipital cortex and right fusiform gyrus. In addition, early category-specific inversion effects were found well beyond visual areas. Our results provide the first direct evidence that category-specific processing in high-level category-sensitive cortical areas already takes place within the first 100-ms of visual processing, significantly earlier than previously thought, and suggests the existence of fast category-specific neocortical routes in the human brain.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Orientación
/
Reconocimiento Visual de Modelos
/
Estimulación Luminosa
/
Corteza Visual
/
Magnetoencefalografía
/
Vías Nerviosas
Tipo de estudio:
Clinical_trials
Límite:
Adult
/
Female
/
Humans
/
Male
Idioma:
En
Revista:
PLoS One
Asunto de la revista:
CIENCIA
/
MEDICINA
Año:
2008
Tipo del documento:
Article
País de afiliación:
Países Bajos
Pais de publicación:
Estados Unidos