Prior research has shown that the human brain responds similarly to desired substances of abuse as to cute babies’ faces, with both cues triggering the release of dopamine-based brain rewards. A new functional MRI study has documented that the baby-face response is markedly muted in mothers who have substance addictions—even when the babies are their own.
Sohye Kim, PhD, of Baylor College of Medicine in Houston and colleagues report on their work in a study published online July 26 in Human Brain Mapping.
The researchers used fMRI to scan 36 mothers of six-month-olds while showing the women images of happy and sad infant faces.
All the women were inpatients at a drug-rehab center. Half the images were of each woman’s own child; the other half were of unknown age-matched infants.
When viewing happy face images of their own infant, mothers with addictions “showed a striking pattern of decreased activation” in dopamine- and oxytocin-innervated brain regions, including the hypothalamus, ventral striatum and ventromedial prefrontal cortex, the authors report.
They point out that these are regions in which increased activation has previously been observed in mothers without addictions.
Kim and colleagues believe their findings are the first to confirm that mothers with addictions have reduced activation in key reward regions of the brain in response to their own babies’ faces.
“Maternal addiction constitutes a major public health problem affecting children, with high rates of abuse, neglect and foster care placement,” they write.
Kim expounds on that point in a news item posted by the school.