Developmental intersensory interference: Premature visual experience suppresses auditory learning in ducklings

Test results showed that the deleterious effect of premature visual experience would appear to be a transient phenomenon related to the distracting effects produced by concurrent auditory and visual stimulation that overtaxes the attentional abilities of the “preterm” duckling.

Abstract

The present study was undertaken to test a recent hypothesis that in human and animal infants, premature stimulation in a later developing sensory system (e.g., vision) interferes with the normal functioning of an earlier developing system (e.g., audition) when the earlier system is still undergoing maturation. When mallard duck embryos are exposed to a mallard maternal assembly call they learn the features of the call as evidenced by their postnatal behavioral preference for it over an unfamiliar maternal call of the same species. However, if the embryos are given the opportunity to experience pattern vision prematurely, while undergoing auditory exposure to the call, they do not learn the maternal call. Further experiments showed that the interference only occurs when the exposure to the maternal call is concomitant with the premature visual experience. When otherwise prematurely visually stimulated duck embryos are exposed to the maternal call during periods of darkness they learn the call. Also, the premature visual experience does not interfere with the later postnatal auditory learning ability of such embryos. They are capable of learning the call when they are exposed to it after hatching. Consequently, the deleterious effect of premature visual experience would appear to be a transient phenomenon related to the distracting effects produced by concurrent auditory and visual stimulation that overtaxes the attentional abilities of the “preterm” duckling. Premature visual experience does not necessarily result in a persistent alteration in the developmental competence of the earlier developing auditory system, as predicted by a strong form of the developmental intersensory interference (DII) hypothesis. A weak form of the DII hypothesis is offered, which is predicated on transient, rather than permanent, effects involving momentary attentional difficulties caused by the concurrent stimulation of two immature or incompletely developed sensory systems.