New research has found that people who have experienced childhood emotional neglect and adversity could pass on neurobiological imprints of fear and anxiety to their own children.
These cross-generational imprints were found to influence the brain development of children, resulting in altered brain circuitry between the amygdala (fear and anxiety processing part of the brain) and two other brain regions, the prefrontal cortex and the dorsal anterior cingulate cortex – both areas involved in decision making and the regulation of emotions.
The findings have been published in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging.
"These results show that our brain development is not only shaped by what happens in our own life, but is also impacted by things that happened to our parents before we were even conceived," lead author of the study, Dr Cassandra Hendrix, said in a statement.
The authors studied 48 black mother-child pairs during the first trimester of pregnancy. The mothers were given a questionnaire to assess their childhood trauma and adversity, which included experiences of early childhood emotional neglect and abuse. All the mothers were assessed for current prenatal stress levels, including current depression and anxiety.
One month after the mothers gave birth, their children underwent brain scans using resting-state functional magnetic resonance imaging (fMRI), a brain scan technique that is non-invasive and can be used on babies while they are sleeping.
"These remarkable results leverage our ability to image the brain and its functioning very early in life," said Cameron Carter, MD, Editor of Biological Psychiatry: Cognitive Neuroscience and Neuroimaging.
The study authors found that babies from mothers who had experienced more childhood emotional neglect – according to the self-reported questionnaire the mothers answered – had more connections between the brain's Amygdala and cortical regions.
Taking stress into account, the researchers found the more emotional neglect the mother had experienced, the more interconnected the baby's amygdala was with frontal cortical regions of the brain.
Nevertheless, it is not yet clear what impact the stronger connected amygdala and frontal cortical regions may have in the babies of mothers that experienced increased emotional neglect. "The neural signature we observed in the 1-month-old infants of emotionally neglected mothers may be a mechanism that leads to increased risk for anxiety, or it could be a compensatory mechanism that promotes resilience in case the infant has less supportive caregivers." Dr. Hendrix explained, "In either case, emotional neglect from a mother's own childhood seems to leave behind a neural signature in her baby that may predispose the infant to more readily detect threat in the environment almost from birth. Our findings highlight the importance of emotional support early in life, even for subsequent generations."
The findings illustrate that intergenerational imprints of fear and anxiety may be passed on from mothers to their babies, however, the consequences of such transfer are not yet clear. More research is required to ascertain more precisely what such transfers of emotional experience might entail between mother and baby.
"The findings add to evidence of the intergenerational consequences of early life adversity, such as maternal neglect," Dr Carter concluded. "Future studies that follow children longitudinally will help us understand the functional significance of these changes in brain function in terms of the emotional and social development of children of mothers who experienced early neglect."