Quality of Early Parental Care Reported by Mothers is Related to Anterior Cingulate Response to Own Infant Stimuli: Preliminary Findings
Introduction
A mother's behaviour towards her infant is influenced by numerous factors including her early experiences. One facet of early experience is the quality of parental care mothers received in their family of origin, for example, subjective reports of the level of parental affection, expressed emotion, empathy and physical/emotional abuse. In experimental animals, the quality of maternal care influences neural systems that regulate the onset and maintenance of maternal behaviour. In rats, this is thought to be mediated by an “approach-avoidance” system that includes brain regions involved in reward (nucleus accumbens), stimulus salience (amygdala) as well as attention and affect/aversion (prefrontal cortex, ACC) (Numan, Fleming & Levy, 2006). Our goal was to examine, in human mothers, the influence of early experience in their family of origin on the neural correlates underlying maternal response to own and unfamiliar (i.e., “other”) infant faces, with particular attention to brain regions involved in arousal, stimulus salience and motivation/reinforcement (e.g., nucleus accumbens, amygdala, thalamus, hippocampus, orbitofrontal cortex and anterior cingulate cortex (ACC)).
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Methods
Between 3- 5 months postpartum, 12 healthy mothers completed a block-design face-rating task during functional magnetic resonance imaging (fMRI). During the task, mothers viewed four different 36-second infant face conditions (own-positive, own-negative, other-positive, other-negative) presented in a random order and separated by an unrelated 36 to 42-second distraction condition; the task was repeated three times. For each face condition, mothers viewed six infant faces and rated how each face
Results
Following a fixed-effects analysis, two contrasts were performed: own positive – other positive and own negative – other negative. In terms of our regions of interest, viewing/rating one's own positive infant face (in comparison to an unfamiliar (i.e., “other”) positive infant face) was associated with increased BOLD response (p <0.05, corrected) in the parahippocampal gyrus and thalamus and decreased BOLD response (p <0.05, corrected) in the perigenual ACC (pgACC, Figure 1a). No significant
Conclusions
Our preliminary results in mothers suggest that viewing/rating one's own infant face is accompanied by decreases in activity in the pgACC. As increased activity in the pgACC has been strongly linked to negative affective states such as aversion, anxiety and depression, it is possible that the decreased pgACC activity observed in our study is related to the inhibition of an aversive response/negative arousal state, which, in rats, is essential for maternal behaviour. In light of this hypothesis,