Influence of spatial frequency and handedness on hemispheric asymmetry in visually steady-state evoked potentials.
Neuropsychologia
; 27(3): 315-24, 1989.
Article
em En
| MEDLINE
| ID: mdl-2710322
ABSTRACT
Recent suggestions on the involvement of the spatial frequency of visual stimuli in the hemispheric lateralization were investigated by recording steady-state evoked potentials in two groups of subjects:
five right-handers and five left-handers. Sinusoidal gratings at spatial frequency of 0.5, 1, 3, 4, 6, 8, 10, 12 or 16 cpd were phase reversed at 4 Hz or 12 Hz. Evoked potentials recorded from temporal leads over each hemisphere were submitted to a FFT analysis. Results concern the amplitude of the fundamental component. In right-handers, the temporal frequency was the deciding factor of the lateralization the evoked activities were greatest in the RH at 4 Hz and in the LH at 12 Hz. This effect was obvious for the range of spatial frequencies from 3-12 cpd. Results, discussed in terms of global/local information, suggested the existence of two transient and sustained systems. In left-handers, both the spatial and temporal parameters were relevant to the lateralization. A spatio-temporal interaction was observed which was reversed at 6 cpd.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Potenciais Evocados Visuais
/
Lateralidade Funcional
Limite:
Adult
/
Female
/
Humans
/
Male
Idioma:
En
Revista:
Neuropsychologia
Ano de publicação:
1989
Tipo de documento:
Article
País de afiliação:
França