A four-day period of bimodality auditory and visual experience is sufficient to permit normal emergence of the map of auditory space in the guinea pig superior colliculus.

Previous work has shown that if guinea pigs are deprived of simultaneous visual and auditory experience during a 4-day period 26-30 days after birth (DAB), this prevents the normal emergence of an auditory space map in the superior colliculus. The present work reports that if this 4-day period is the only developmental period in which the animals have simultaneous bimodality experience, the auditory space map appears at the normal time. Apart from this time-window animals were deprived of either visual experience (by dark-rearing) or of normal auditory experience (by rearing in an environment of omnidirectional masking noise). We conclude that the period 26-30 DAB is a crucial developmental period during which coincident auditory and visual experience is utilized in the initial formation of the collicular map of auditory space.