Brain-Behavior Associations During Interactions Between Caregivers and Infants.

Previous research has shown that infants' abilities to sustain attention are influenced by caregivers' attentional behaviors. Here, we inquired whether brain function in infants was linked to brain function in caregivers during attention periods in dyadic interactions, and whether this brain function was associated with visual short-term memory in infants. Caregivers (n = 90, mean age = 33.5 years) and infants (n = 91, mean age = 251.3 days) were recorded for 5- to 7-min as they naturalistically played with toys. During these interactions, brain function was recorded using functional near-infrared spectroscopy (fNIRS). To assess visual short-term memory, infants were presented with a preferential looking task. Video recordings were coded for periods of joint attention between caregivers and infants, and periods of continued attention in infants. fNIRS data was processed to extract significant clusters of activation. Our findings revealed that temporo-parietal engagement in both caregivers and infants. Specifically, left superior temporal gyrus activation in caregivers during joint attention was linked to duration of joint attention, duration of continued attention, and visual short-term memory in infants. Our findings highlight cortical mechanisms engaged in caregivers and infants during dyadic interactions, and importantly, how these mechanisms are linked to visual short-term memory.