Incremental binocular amplitude of the pattern visual evoked potential during the first five months of life: electrophysiological evidence of the development of binocularity

Abstract

The amplitude of the pattern visual evoked potential (VEP) of a binocular stimulus has been shown to be generally larger than the VEP obtained monocularly. There is evidence that this effect can be considered an electrophysiological index of fusion. To study how binocular vision develops in infancy we evaluated the incremental binocular amplitude (IBA) in three infants in a longitudinal investigation during the first five months of life. The stimuli were phase-alternating square-wave gratings with spatial and temporal parameters chosen to be appropriate for neonates. IBA was defined as the percentage increment of the largest binocular response compared with the monocular response. In the first two months of life IBA values were near zero, that is, no summation occurred. Between the second and third month IBA values rose markedly and after the third month its value was greater than 100%, demonstrating binocular facilitation. Thus in the first two months of life the eyes do not seem to cooperate as in adults. By the second and third month the binocular pattern VEP reflects an increasing binocular interaction. Other studies of the development of stereopsis have also found evidence of binocularity at similar ages.

Vii-1 : Maturation Visuelle Et Électrophysiologie Pédiatrique

“…Le fonctionnement cortical et particulièrement les coïncidences temporelles des potentiels d'action émis [Shatz, 1992] sont à l'origine d'afférences dominantes provenant d'un oeil ou de l'autre pour la définition des colonnes de dominance oculaire oeil droit -oeil gauche [Kalil, 1990], l'équilibre entre chacune de ces colonnes dépendant du bon fonctionnement de chaque oeil. Les processus de fusion binoculaire se mettent en place à partir de l'âge de trois mois [Penne et al, 1987].…”

“…Les processus de fusion binoculaire se mettent en place à partir de l'âge de trois mois [Penne, et al, 1987]. Normalement vers l'âge de six mois, les PEV damier (cases 60') après stimulation binoculaire sont d'amplitude supérieure à celle des PEV damier après stimulation monoculaire [Apkarian, et al, 1981] (figure VII-1-28).…”

Visuell evozierte Potentiale bei Säuglingen und Kleinkindern

“…So entwickelt sich die Kontrastsensitivität in den ersten 6 Monaten [3]. Das Binokularsehen dürfte in den ersten drei Lebensmonaten ausreifen [23].…”