We propose an alternative to the conventional view that limitations on infant functioning are handicaps to be overcome. According to our view, limitations, particularly of the sensory systems, produce adaptive advantages for infants by facilitating perceptual organization. During embryogenesis, developmental rates of sensory systems are unequal so that onset of functioning is sequential. We argue that such differential onset results in relative independence among emerging systems, thereby reducing competition which helps regulate subsequent neurogenesis and functioning. In addition to prenatal effects, neonatal sensory limitations are discussed as a major source of perceptual organization. Limitations reduce the amount of information with which the infant must contend and promote temporal contiguity between multimodal attributes of a stimulus. Although we focus on human perceptual development, our view is a broadly based comparative one. Thus, other organisms have evolved means of restricting sensory input, and evidence is cited suggesting the importance of this reduced input in regulating normal perceptual development.

Two studies examined the theory that early limitations on sensory functioning contribute to the organization of a structure for perceptual development and intersensory functioning. Rat pups' eyelids were surgically opened on Day 7, following which the development of homing to their nest site was investigated, with each animal alone in its living cage. Control pups increased homing until Day 14, and then decreased. Experimental pups showed no such decline, with the highest rate of homing evident on the last day of testing. The importance of visual cues for this altered development of homing was examined. Visual cues for the home were reduced by removing all shavings during testing, while leaving an odorous substrate in place. Under these conditions, both groups showed the characteristic increase and decline in homing, suggesting that premature eyelid opening results in a modification of the distribution of attention to visual and olfactory characteristics of the nest.

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