Investigating the Influence of Infant-Directed Speech on Attention and Visual Processing: An ERP and Gamma Activity Study

Evidence suggests that infant attention for and learning of speech stimuli is enhanced by infant-directed speech (IDS), characterized by a higher mean pitch and higher variability in prosody. Much less is known regarding the potential general effect of IDSon cognitive processes, such as attention and learning during the encoding and processing of visual information. This study investigates the effect of IDS cueing on visual processing in 4-month-old infants using an EEG paradigm. During the encoding phase,an image will be accompanied by a speech cue in infant-or adult-directed speech (ASD). The same image will be presented again in a silent target phase. We predict increased gamma synchronization over frontal regions, indicative of attentional focus,while listening to IDS rather than ADS. The attentional focus is assumed to also enhance processing of visual stimuli. As the Nc ERP component is associated with attention, Nc amplitudewill be measured during the target phase. Stimuli cued by IDS will elicit a smaller Nc, due to more comprehensive processing during cueing. Together, projected effects are consistent with less attention and less comprehensive processing during ADS than IDS cueing. The investigation will thus broaden our knowledge regarding earlycognitive effects of speech registers, paving the way to a deeper understanding of early multimodal learning via attention.