A comparison of preterm and full-term infants on auditory discrimination at four months and on Bayley Scales of Infant Development at eighteen months.

A variable-trials auditory discrimination procedure was employed to measure individual differences in stimulus encoding and memory among 4-month-old preterm and full-term infants who were equated on conceptional age. It was assumed that differences among individuals on this task would be predictive of cognitive functioning at 18 months. At 4 months, cardiac response to repetitive and novel auditory stimulation was assessed. At 18 months, infants were tested on the Bayley Scales of Infant Development. When equated on level of maturity, preterm infants were indistinguishable from full-term infants in their rates of response decrement to stimulus repetition and in their subsequent response to a novel stimulus. Furthermore, these 2 groups did not differ in mental or motor performance at 18 months. A second finding was that responsiveness to auditory novelty at 4 months was a strong predictor of 18-month mental performance for females but not for males. Alternatively, rate of response decrement measured at 4 months was not predictive of Bayley scores for either sex. Auditory discrimination measures were unrelated to motor performance.