title: Genetic variation in CD38 and breastfeeding experience interact to impact infants' attention to social eye cues.
abstract: Attending to emotional information conveyed by the eyes is an important social skill in humans. The current study examined this skill in early development by measuring attention to eyes while viewing emotional faces in 7-mo-old infants. In particular, we investigated individual differences in infant attention to eyes in the context of genetic variation (CD38 rs3796863 polymorphism) and experiential variation (exclusive breastfeeding duration) related to the oxytocin system. Our results revealed that, whereas infants at this age show a robust fear bias (increased attention to fearful eyes), their attention to angry and happy eyes varies as a function of exclusive breastfeeding experience and genetic variation in CD38. Specifically, extended exclusive breastfeeding duration selectively enhanced looking preference to happy eyes and decreased looking to angry eyes. Importantly, however, this interaction was impacted by CD38 variation, such that only the looking preferences of infants homozygous for the C allele of rs3796863 were affected by breastfeeding experience. This genotype has been associated with reduced release of oxytocin and higher rates of autism. In contrast, infants with the CA/AA genotype showed similar looking preferences regardless of breastfeeding exposure. Thus, differences in the sensitivity to emotional eyes may be linked to an interaction between the endogenous (CD38) and exogenous (breastfeeding) availability of oxytocin. These findings underline the importance of maternal care and the oxytocin system in contributing to the early development of responding to social eye cues.
authors.affiliation: Early Social Development Group, Max Planck Institute for Human Cognitive and Brain Sciences, 04103 Leipzig, Germany; krol@cbs.mpg.de tg3ny@virginia.edu.
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Krol
authors.affiliation: Department of Psychology, National University of Singapore, Singapore 117570;
authors.forename: Mikhail
authors.initials: M
authors.lastname: Monakhov
authors.affiliation: Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228;
authors.forename: Poh San
authors.initials: PS
authors.lastname: Lai
authors.affiliation: Department of Psychology, National University of Singapore, Singapore 117570;
authors.forename: Richard P
authors.initials: RP
authors.lastname: Ebstein
authors.affiliation: Early Social Development Group, Max Planck Institute for Human Cognitive and Brain Sciences, 04103 Leipzig, Germany; Department of Psychology, University of Virginia, Charlottesville, VA 22903 krol@cbs.mpg.de tg3ny@virginia.edu.
authors.forename: Tobias
authors.initials: T
authors.lastname: Grossmann
mesh_terms: D051997:ADP-ribosyl Cyclase 1 / Q000235:genetics*; D001288:Attention; D001321:Autistic Disorder / Q000235:genetics*; D001942:Breast Feeding / Q000523:psychology*; D004644:Emotions / Q000502:physiology*; D005403:Fixation, Ocular; D014644:Genetic Variation; D006801:Humans; D007223:Infant; D008562:Membrane Glycoproteins / Q000235:genetics*; D009633:Nonverbal Communication / Q000502:physiology* / Q000523:psychology; D010121:Oxytocin; D010775:Photic Stimulation; D011795:Surveys and Questionnaires
chemical_list: D008562:Membrane Glycoproteins; D010121:Oxytocin; C498154:CD38 protein, human; D051997:ADP-ribosyl Cyclase 1
keywords: CD38; breastfeeding; emotion perception; infancy; oxytocin