Audiovisual speech perception in noise in younger and older bilinguals.

Speech perception in noise becomes increasingly difficult with age. Similarly, bilinguals often have difficulty with speech perception in noise in their second language (L2) due to less developed language knowledge in L2. Little is known about older bilinguals, who experience age-related sensory and cognitive changes but have extensive L2 experience. Furthermore, while audiovisual (AV) speech cues and supportive sentence context facilitate speech perception in noise in native listeners, much less is known for bilingual listeners, particularly older bilinguals. This study investigated how much young (n = 30) and older (n = 31) French-English/English-French bilinguals benefit from AV speech cues and sentence context in their first (L1) and second language during speech perception in noise. Participants completed the task in L1 and L2. Importantly, the level of background noise was individually calibrated for each participant to equate performance during the baseline task. The results suggest that there were no age differences in overall performance during the speech perception in noise task. However, older adults showed smaller language effects and smaller modality effects (i.e., comparing auditory-only speech perception to audiovisual speech perception) compared to younger adults. Furthermore, both young and older bilinguals benefited from AV speech cues and sentence context in both of their languages. However, during L2 speech perception in noise, visual speech cues were particularly important for young adults. In contrast, older adults show equal benefit from visual speech cues in L1 and L2. Taken together, these findings extend current models of AV speech perception to a second language in both younger and older adults. Furthermore, the findings suggest that bilinguals are likely to benefit from visual speech cues and supportive sentence context, although this benefit may differ slightly between younger and older bilinguals. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

From early birds to night owls: a longitudinal study of actigraphy-assessed sleep trajectories during the transition from pre- to early adolescence.

STUDY OBJECTIVES: Pre- and early adolescence are believed to constitute periods of important age-related changes in sleep. However, much of the research on these presumed developmental changes has used cross-sectional data or subjective measures of sleep, limiting the quality of the evidence. In addition, little is known about the development of certain features of the sleep-wake cycle pertaining to regularity (e.g. weekend-weekday differences and intra-individual variability) or circadian rhythms (e.g. sleep midpoint). METHODS: This study examined the sleep trajectories of 128 typically developing youth (69 girls) from ages 8 to 12 years on four sleep characteristics: sleep onset, sleep offset, total sleep time (TST), and sleep midpoint. For each of these characteristics, actigraphy-derived estimates of typical (i.e. mean) sleep and sleep regularity were obtained at each time point. Multilevel growth curves were modeled. RESULTS: Overall, the sleep-wake cycle significantly changed between 8 and 12 years. Mean sleep onset, offset and midpoint exhibited an ascending curvilinear growth pattern that shifted later with age, while mean TST decreased linearly. Weekend-weekday differences (social jetlag) for sleep offset and midpoint became more pronounced each year. Weekday TST was longer than weekend TST, though this difference became smaller over time. Finally, intra-individual variability increased over time for all sleep characteristics, with variability in TST ascending curvilinearly. Important between-person and sex differences were also observed. CONCLUSION: This study reveals the marked changes that occur in the sleep of typically developing pre- and early adolescents. We discuss the potential implications of these trajectories.