Augmented prenatal auditory stimulation alters postnatal perception, arousal, and survival in bobwhite quail chicks.
This study examined whether previously reported effects of altered prenatal sensory experience on subsequent acceleration of intersensory development in precocial birds are mediated by mechanisms sensitive to the overall amount of stimulation provided. Results revealed that bobwhite quail chicks exposed to substantially augmented amounts of prenatal auditory stimulation show altered patterns of species-typical perceptual development. Specifically, chicks continued to respond to maternal auditory cues into later stages of postnatal development and failed to demonstrate responsiveness to maternal visual cues. In addition, embryos exposed to substantially augmented amounts of prenatal auditory stimulation exhibited a higher level of behavioral arousal and higher mortality rates than embryos provided either moderately augmented amounts or no additional amount of prenatal auditory stimulation. These findings suggest that substantially increased amounts of prenatal sensory stimulation can interfere with the emergence of species-typical patterns of postnatal perceptual functioning and lend support to the notion that sensory stimulation that falls within some optimal range maintains or facilitates normal patterns of perceptual development, whereas stimulation beyond the range of the species norm can result in intersensory and intersensory interference.