In the guinea‐pig the development and maintenance of the superior collicular (SC) auditory space map requires both auditory and visual experience. This paper reports the results of experiments in which adult animals (of different ages) were dark‐reared for 4 weeks to define the extent of the period of susceptibility to visual deprivation of the SC auditory map. Dark‐rearing for 4 weeks from 100, 150 or 200 days after birth caused degradation of spatial tuning and topography of multi‐unit auditory responses in the SC. In contrast, animals reared in the dark from 250 days after birth showed spatially tuned auditory responses similar to those seen in normal animals. These data suggest that the SC auditory space map in the adult guinea‐pig remains susceptible to visual deprivation up to 200 days after birth.

SUMMARYThere were two primary aims of this study. First, to observe if the map of auditory space in the superior colliculus (SC) of the guinea-pig could recover after periods of normal visual experience following visual deprivation during the crucial period. Second, to determine whether any degradation of the space map was observed when the animal was visually deprived for different lengths of time after the crucial period. Animals deprived of visual experience during the crucial period and then allowed normal experience did show a limited ability to construct a SC auditory space map. Whereas visual deprivation following normal auditory and visual experience during the crucial period caused a profound degradation, of both spatial tuning and topography, of auditory receptive fields in the SC. Additional data indicate that the SC auditory space map remains vulnerable to visual deprivation until at least 100 days after birth.