Joint attention initiation and exogenous attention allocation during mother-infant interaction at 12 months associate with 24-month vocabulary composition

This database includes the raw data linked with the paper "Joint attention initiation and exogenous attention allocation during mother-infant interaction at 12 months associate with 24-month vocabulary composition". The present study explores how early forms of attention during mother-infant interaction at 12 months (i.e., exogenous attention allocation and joint attention initiation) might modulate individual differences in 24 months language development. Methods Forty-six infants (born at term, from healthy pregnancies) and their mothers were included. At infants’ 12-month-age, mothers and infants participated to a video-recorded face-to-face interaction via teleconferencing. After 2 minutes of free playful interaction, researchers introduced series of three socially meaningful sounds. While the sounds played (30 seconds), mothers were instructed to maintain neutral expressions. After each exposure, play resumed for 30 seconds (reprise). Episodes were micro-analytically coded. The proportion of time of infant's gaze to the auditory stimulus source was coded as Exogenous attention allocation (EAA) and to the mother as Social Attention to mother (SAM). Joint attention initiation (JAI) was measured as the frequency of occurrence of a sequence of infant gaze behaviours (within 2 seconds): (1) orienting to the source; (2) orienting to the mother; (3) orienting back to the source. At 24 moths, mothers filled the McArthur Bates Communication Development Inventory (CDI). Quantitative measure of vocabulary size was computed (number of words produced) and qualitative vocabulary composition (%) was obtained for four major word categories (i.e., social, nouns, predicates and closed-class words). Results (in brief) Findings showed significant negative associations between early life EAA and later vocabulary composition (i.e., predicate %). This association was modulated by JAI: infants displaying lower levels of JAI showed a negative association between EAA and language development.