Attentional differences in audiovisual face perception between full- and preterm very low birthweight toddlers.

AIM

To investigate whether rightward attention to the mouth during audiovisual speech perception may be a behavioural marker for early brain development, we studied very preterm and low birthweight (VLBW) and typically developing (TD) toddlers.

METHODS

We tested the distribution of gaze points in Japanese-learning TD and VLBW toddlers when exposed to talking, silent and mouth moving faces at 12, 18 and 24 months (corrected age). Each participant was categorised based upon the area they gazed at most (Eye-Right, Eye-Left, Mouth-Right, Mouth-Left) per stimulus per age. A log-linear model was applied to three-dimensional contingency tables (region, side and group).

RESULTS

VLBW toddlers showed fewer gaze points than TD toddlers. At 12 months, more VLBW toddlers than TD toddlers showed left attentional bias toward any one face; however, this difference in attention asymmetry receded somewhat by 24 months. In talking condition, TD toddlers showed right attentional bias from 12 to 24 months, whereas VLBW toddlers showed such bias upon reaching 24 months. Additionally, more TD toddlers than VLBW toddlers attended to the mouth.

CONCLUSION

Delays in exhibiting the attentional bias for an audiovisual face or general faces displayed by typically developing children might suggest differential developmental timing for hemispheric specialisation or dominance.