Neural basis of maternal love as a vital human emotion

Abstract

Maternal love, which may be the core of maternal behavior, is essential for the mother-infant attachment relationship and is important for an infant’s development and mental health. Therefore, maternal love can be considered a vital human emotion. Using video clips, we examined patterns of maternal brain activation in response to infant cues. We performed functional magnetic resonance imaging (fMRI) measurements while 13 mothers viewed video clips of their own infants and other infants (all approximately 16 months of age) who demonstrated two different attachment behaviors. We found that a limited number of the mother’s brain areas were specifically involved in maternal love, namely orbitofrontal cortex (OFC), striatum, anterior insula, and periaqueductal gray (PAG). Then, we proposed a schematic model of maternal love, based on integration of the two systems in the OFC: the dopamine reward system (OFC, striatum) and the interoceptive information processing system (OFC, insula, PAG). Additionally, we found a strong and specific brain response in a mother viewing her distressed infant. The neural activation pattern was found in the dorsal OFC (dOFC), the dorsolateral prefrontal cortex (DLPFC), ventrolateral prefrontal cortex (VLPFC), dorsomedial prefrontal cortex (DMPFC), dorsal anterior cingulate cortex (dACC), posterior cingulate cortex (PCC), caudate nucleus, supplementary motor area (SMA), and posterior superior temporal sulcus/temporoparietal junction (pSTS/TPJ). These results showed a highly elaborate neural mechanism, based on the above neural basis of maternal love, mediating the diverse and complex maternal behaviors that mothers engage in when raising and protecting their own infants.