Converging neural and behavioral evidence for a rapid, generalized response to threat-related facial expressions in 3-year-old children

• Published in: NeuroImage (Orlando, Fla.) Vol. 229; p. 117732
• Main Authors: Xie, Wanze, Leppänen, Jukka M., Kane-Grade, Finola E., Nelson, Charles A.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.04.2021; Elsevier Limited; Elsevier
• Subjects: Age; Anger; Behavior; Bias; Children; Children & youth; Emotions; Event-related potentials; Infants; Learning algorithms; Machine learning; Physical characteristics; Spectrum analysis; Threats
• ISSN: 1053-8119; 1095-9572; 1095-9572
• DOI: 10.1016/j.neuroimage.2021.117732

•Children's ERP and behavioral responses to facial expressions converge on an enhanced response to threat-related (i.e., fearful and angry) faces at 3 years of age.•A support vector machine learning model using ERP responses to threat reliably predicts overt attentional dwell time for threat-related faces.•There is little within-subject correlation between threat-bias attention in infancy and at 3 years of age. Electrophysiological studies on adults suggest that humans are efficient at detecting threat from facial information and tend to grant these signals a priority in access to attention, awareness, and action. The developmental origins of this bias are poorly understood, partly because few studies have examined the emergence of a generalized neural and behavioral response to distinct categories of threat in early childhood. We used event-related potential (ERP) and eye-tracking measures to examine children's early visual responses and overt attentional biases towards multiple exemplars of angry and fearful vs. other (e.g., happy and neutral) faces. A large group of children was assessed longitudinally in infancy (5, 7, or 12 months) and at 3 years of age. The final ERP dataset included 148 infants and 132 3-year-old children; and the final eye-tracking dataset included 272 infants and 334 3-year-olds. We demonstrate that 1) neural and behavioral responses to facial expressions converge on an enhanced response to fearful and angry faces at 3 years of age, with no differentiation between or bias towards one or the other of these expressions, and 2) a support vector machine learning model using data on the early-stage neural responses to threat reliably predicts the duration of overt attentional dwell time for threat-related faces at 3 years. However, we found little within-subject correlation between threat-bias attention in infancy and at 3 years of age. These results provide unique evidence for the early development of a rapid, unified response to two distinct categories of facial expressions with different physical characteristics, but shared threat-related meaning.