The influence of CHRNA4, COMT, and maternal sensitivity on orienting and executive attention in 6-month-old infants

- Investigation of attention caregiving and genetics (CHRNA4 and orienting; COMT and control).
- Genetic, maternal sensitivity, and eye tracking data collected with 217 infants.
- Orienting attention predicted by CHRNA4 and maternal sensitivity interaction.
- Attention involving orienting and control predicted by CHRNA4 and COMT interaction.
- Attentional control was greatest in COMT VAL carriers.

Despite claims concerning biological mechanisms sub-serving infant attention, little experimental work examines its underpinnings. This study examines how candidate polymorphisms from the cholinergic (CHRNA4 rs1044396) and dopaminergic (COMT rs4680) systems, respectively indicative of parietal and prefrontal/anterior cingulate involvement, are related to 6-month-olds' (n = 217) performance during a visual expectation eye-tracking paradigm. As previous studies suggest that both cholinergic and dopaminergic genes may influence susceptibility to the influence of other genetic and environmental factors, we further examined whether these candidate genes interact with one another and/or with early caregiving experience in predicting infants' visual attention. We detected an interaction between CHRNA4 genotype and observed maternal sensitivity upon infants' orienting to random stimuli and a CHRNA4-COMT interaction effect upon infants' orienting to patterned stimuli. Consistent with adult research, we observed a direct effect of COMT genotype on anticipatory looking to patterned stimuli. Findings suggest that CHRNA4 genotype may influence susceptibility to other attention-related factors in infancy. These interactions may account for the inability to establish a link between CHRNA4 and orienting in infant research to date, despite developmental theorizing suggesting otherwise. Moreover, findings suggest that by 6 months, dopamine, and relatedly, the prefrontal cortex/anterior cingulate, may be important to infant attention.