Touch Supports Word Segmentation More Than Statistics But is Not Mediated by Attention.

Multisensory information is integral to infants' language experiences and research has suggested that infants can use multisensory cues to support their segmentation of wordforms continuous speech. However, the role of multisensory cues in wordform segmentation compared to that of cues present in the acoustic stream alone (e.g., transitional probability) remains unclear. In the current study, we investigated word segmentation with aligned tactile cues in 8.5-month-old infants to explore how these infants weight tactile cues compared to, as well as in combination with, transitional probability cues. Aligned tactile cues had a significant impact on wordform segmentation and recognition performance as assessed through orientation time in Headturn Preference Procedure, while transitional probability cues did not have a significant impact. We also explored whether performance was related to attention as measured by heart rate defined sustained attention (HRDSA). Overall, duration of sustained attention assessed through HRDSA was associated with overall longer orientation times regardless of stimulus type, but HRDSA did not vary significantly with tactile cue presence/absence or transitional probabilities.