Maternal anxiety shapes prediction error responses in the infant brain.

Significance: Postnatal maternal anxiety affects a substantial number of new mothers and is linked to long-term risk for anxiety in their offspring. Yet, the neural mechanisms through which postnatal maternal anxiety influences early cognitive development remain unclear. We investigated whether postnatal maternal anxiety shapes how infant brains respond to unexpected events-prediction errors-which are central to learning in uncertain environments. Aim: We examined prediction error processing in 6- to 8-month-old infants using high-density diffuse optical tomography and eye-tracking. We hypothesized that neural responses in the medial prefrontal cortex (mPFC) would vary with maternal anxiety levels. Approach: Infants viewed audiovisual events where expected outcomes were occasionally omitted, eliciting prediction errors. Hemodynamic responses in the frontal cortex were analyzed using a general linear model, with trial-by-trial gaze data as a parametric modulator. Maternal anxiety was measured using the state-trait anxiety inventory. Results: Prediction error responses were localized to the mPFC and were only detectable when controlling for infant attention using eye-tracking. Cortical activation in response to unexpected stimuli was significantly enhanced in infants of mothers with higher trait anxiety. Conclusion: Our findings suggest that maternal anxiety modulates prediction error processing in the infant brain, potentially shaping early sensitivity to environmental unpredictability and conferring risk for later anxiety.