[Value of cerebral mapping in the study of amblyopia]

The Alpha attenuation response to a visual stimulation was studied by quantified electroencephalogram for three posterior electrodes 01, 02, Pz, in twenty-five patients presenting either functional, deprived or cured amblyopia. A sample group allows the comparison of differences of visual attenuation responses with or without penalisation on the normal eye. The decreased percentage of cerebral activity during visual stimulations, in the Alpha band of cerebral frequencies represents the visual reactivity. Cerebral activity was checked during different sequences and visual reactivity was calculated. It demonstrates that the stimulation of the amblyopic eye shows a visual Alpha attenuation response only slightly more significant than the one obtained by stimulation of the healthy or normalised eye, or the stimulation of both eyes at the same time. But there is no change of visual Alpha attenuation when a +15 diopters penalisation is used as an optical correction for the normal eye. These findings allow us to disregard either deficient visual acuity or monocular stimulation as a cause of this phenomenon and seems to suggest a cortical neutralization as its origin. This technique could possibly objectify the therapeutic improvements during the treatment. These facts are in accordance with the neurophysiological studies of Hubel and Wiesel.