How Sleep Affects How 17-Month-Olds Attend Differentially to Learnable vs. Unlearnable Linguistic Patterns

This study tested whether 17-month-olds that were more or less rested attended differentially to learnable vs. unlearnable linguistic patterns. Rested and unrested infants were habituated to learnable or unlearnable pattern types. Infants hearing the learnable pattern were also given head turn preference test trials to test learning of the pattern as a function of being rested or not. Before and after habituation the infants’ cortisol levels were taken to assess whether stress levels were affected differentially as a function of rest and whether the pattern was learnable. Although statistical significance was not obtained, rested infants attended longer to the unlearnable pattern than the learnable one during habituation and unrested infants attended longer to the learnable over the unlearnable pattern. Perhaps this means rested infants are more willing than unrested infants to attempt to solve a problem, even if it is unsolveable. In the learning trials, rested infants did not appear to show a learning affect whereas unrested infants showed a numerical, but not statistically significant, difference in listening times to grammatical and ungrammatical stimuli. Cortisol samples have not yet been analyzed. While no certain conclusions can be made at this point, rest does appear to affect infants’ learning strategies