Cortical oscillations modulated by congruent and incongruent audiovisual stimuli.
Neurol Clin Neurophysiol
; 2004: 15, 2004 Nov 30.
Article
en En
| MEDLINE
| ID: mdl-16012678
Congruent or incongruent grapheme-phoneme stimuli are easily perceived as one or two linguistic objects. The main objective of this study was to investigate the changes in cortical oscillations that reflect the processing of congruent and incongruent audiovisual stimuli. Graphemes were Japanese Hiragana characters for four different vowels (/a/, /o/, /u/, and /i/). They were presented simultaneously with their corresponding phonemes (congruent) or non-corresponding phonemes (incongruent) to native-speaking Japanese participants. Participants' reaction times to the congruent audiovisual stimuli were significantly faster by 57 ms as compared to reaction times to incongruent stimuli. We recorded the brain responses for each condition using a whole-head magnetoencephalograph (MEG). A novel approach to analysing MEG data, called synthetic aperture magnetometry (SAM), was used to identify event-related changes in cortical oscillations involved in audiovisual processing. The SAM contrast between congruent and incongruent responses revealed greater event-related desynchonization (8-16 Hz) bilaterally in the occipital lobes and greater event-related synchronization (4-8 Hz) in the left transverse temporal gyrus. Results from this study further support the concept of interactions between the auditory and visual sensory cortices in multi-sensory processing of audiovisual objects.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Estimulación Luminosa
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Tiempo de Reacción
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Corteza Auditiva
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Corteza Visual
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Estimulación Acústica
Límite:
Adult
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Female
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Humans
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Male
Idioma:
En
Revista:
Neurol Clin Neurophysiol
Asunto de la revista:
NEUROLOGIA
Año:
2004
Tipo del documento:
Article
País de afiliación:
Canadá
Pais de publicación:
Estados Unidos