Current Substance Use and Maternal Neural Responses to Infant Faces and Cries

Postpartum substance use can have lasting impacts on caregiving and child development. Prior work examining maternal substance use and neural responses to infant cues has employed unknown infant face and cry stimuli, categorizing mothers as either substance-using or not, potentially overlooking the complexity and dynamic nature of current substance use. Here, 106 postpartum women were presented with own and unknown infant cues while electroencephalography (EEG) was recorded. Current substance use was assessed through an inclusive continuous approach. The central finding was that higher levels of current substance use were associated with longer delays in the N170 response to infant faces regardless of familiarity, replicating previous work using categorical substance use assessments (i.e., present or absent). Findings highlight the feasibility of continuous measures of substance use and suggest that salience of own infant cues may not be sufficient to override substance use effects on maternal processing of infant cues.