Age-Related Differences in Auditory Statistical Learning of Complex Speech Streams: Evidence From ERPs

Abstract Statistical learning (SL), the ability to pick up regularities in the sensory environment, is a fundamental skill that allows us to structure the world in a regular and predictable way. Although extensive evidence has been gathered from children and adults, the changes that SL might undergo throughout development remain contentious, particularly in the auditory modality (aSL) with linguistic materials. Here, we collected Event-Related Potentials (ERPs) while 5 years-old children and young adults (university students) were exposed to a complex speech stream in which eight three-syllable nonsense words - four with high (1.0) and four with low (.50) transitional probabilities were embedded to further examine how aSL works under less predictable conditions and to enhance age-related differences in the neural correlates of aSL. Moreover, to ascertain how previous knowledge of the to-be-learned regularities might also affect the results, participants performed the aSL task, firstly, under implicit and, subsequently, under explicit conditions. Although behavioral signs of aSL were observed only for adult participants, ERP data showed evidence of aSL in both groups, as indexed by modulations in the N100 and N400 components. A detailed analysis of the neural responses suggests, however, that adults and children rely on different mechanisms to assist aSL.