(P27-054-25) Infant Active Joint Attention and Thiamine Levels Are Robust, Independent Associates of 24-Week Neuro-Cognitive Scores

Objectives: Thiamine-deficient diet undercuts infants’ neuro-cognitive development, yet questions remain about the specific neuro-cognitive abilities affected. We examined possible benefits of maternal thiamine supplementation for Cambodian infants’ active participation in joint attention interactions with their caregivers. Such interactions offer infants key opportunities for learning and thus serve as a further driver of neuro-cognitive development.

Methods: 335 lactating mothers were randomly assigned to receive capsules (0, 1.2, 2.4, or 10mg of thiamine daily from 2-24 weeks postpartum). We assessed infants’ active joint attention via the Secondary Engagement Task (SET) when infants were 12 and 24 weeks. In the SET, mothers showed infants a novel toy as they added and removed engagement cues (gaze/expression, voice/gesture) across five 30-second epochs. Coding from video-recordings determined the proportion of time infants displayed active joint attention (e.g., following caregiver’s gaze, looking between caregiver and toy) across the five SET epochs. 265 infants provided analyzable SET data across both timepoints.

Results: A 4 (supplementation) X 2 (timepoint) X 5 (SET epoch) mixed-design ANOVA revealed significant main effects of timepoint [F(1,261) = 6.94, p = .009] and epoch [F(4,1044) = 68.24, p < .001] on infants’ proportion of active joint attention. However, no significant main effect of supplementation nor interactions of supplementation with other factors emerged (all p’s > .198). Multiple regression revealed that SET active joint attention was a significant independent predictor of 24-week MSEL receptive language scores (Beta = .279, t = 5.13, p < .001) while controlling for other receptive-language predictors [supplementation (p = .006), maternal 2-week milk-thiamine concentration (p = .003), and 2-week MSEL baseline scores (p = .018)].

Conclusions: Maternal thiamine supplementation was not associated with infants’ active joint attention at 12- or 24-weeks. Yet 24-week joint attention was a robust predictor of 24-week cognitive scores. All in all, findings confirmed that both infant joint attention in the SET and thiamine levels independently predicted neuro-cognitive development at 24 weeks.

Funding Sources: NY Academy of Sciences; Bill & Melinda Gates Foundation