Selective attenuation of neural responses to own infant's face in early motherhood: a longitudinal magnetoencephalography study.

The transition to parenthood is associated with heightened neural responsiveness to infant cues, particularly to one's own infant. Yet it remains unclear how this sensitivity changes with caregiving experience. Magnetoencephalography was recorded from 16 first-time mothers viewing images of their own infant, an unfamiliar infant, and an unfamiliar adult at two time points spanning infancy and early toddlerhood. We examined early orbitofrontal activity (∼140 ms), structural face encoding (M170, ∼170 ms), and later motivated attention indexed by the late positive potential (LPP, ∼300-600 ms). Source-level brain data were analyzed with a depth-weighted minimum-norm estimate. Results showed that early LPP responses in the fusiform cortex and late LPP responses in fusiform and occipital regions were larger for own-infant faces at the 1st session but decreased to the level of other faces by the 2nd session. In contrast, early orbitofrontal activity and M170 responses were not modulated by face type or session, and M170 responses showed high temporal stability. These findings suggest that neural activity associated with motivated attention to one's own infant attenuates across early motherhood, whereas early responses reflecting perceptual and affective processes remain stable. The findings provide longitudinal evidence for changes in maternal neural reactivity to one's own infant.