Maternal affect and quality of parenting experiences are related to amygdala response to infant faces

We examined how individual differences in mood and anxiety in the early postpartum period are related to brain response to infant stimuli during fMRI, with particular focus on regions implicated in both maternal behavior and mood/anxiety, that is, the subgenual anterior cingulate cortex (sgACC) and the amygdala. At approximately 3 months postpartum, 22 mothers completed an affect-rating task (ART) during fMRI, where their affective response to infant stimuli was explicitly probed. Mothers viewed/rated four infant face conditions: own positive (OP), own negative (ON), unfamiliar positive (UP), and unfamiliar negative (UN). Mood and anxiety were measured by the Edinburgh Postnatal Depression Scale (EDPS) and the State-Trait Anxiety Inventory-Trait Version (STAI-T); maternal factors related to parental stress and attachment were also assessed. Brain-imaging data underwent a random-effects analysis, and cluster-based statistical thresholding was applied to the following contrasts: OP-UP, ON-UN, OP-ON, and UP-UN. Our main finding was that poorer quality of maternal experience was significantly related to reduced amygdala response to OP compared to UP infant faces. Our results suggest that, in human mothers, infant-related amygdala function may be an important factor in maternal anxiety/mood, in quality of mothering, and in individual differences in the motivation to mother. We are very grateful to the staff at the Imaging Research Center of the Brain-Body Institute for their contributions to this project. This work was supported by an Ontario Mental Health Foundation operating grant awarded to Alison Fleming and a postdoctoral fellowship awarded to Jennifer Barrett.