每日英語跟讀 Ep.780: Severe childhood deprivation reduces brain size, study finds
Children who experience severe deprivation early in life have smaller brains in adulthood, researchers have found.
The findings are based on scans of young adults who were adopted as children into UK families from Romania’s orphanages that rose under the regime of the dictator Nicolae Ceausescu.
Now experts say that despite the children having been adopted into loving, nurturing families in the early 1990s, the early neglect appears to have left its mark on their brain structures.
“I think the most striking finding is … that the effects on the brain have persisted,” said Prof Edmund Sonuga-Barke, a co-author of the study from King’s College London, who added that the results showed neuroplasticity had limits.
“The idea that everything is recoverable, no matter what your experience … isn’t necessarily true — even with the best care you can still see those signs of that earlier adversity,” he said.
The plight of the undernourished children, who had little social contact and received insufficient care, shocked the world when it came to light after the fall of the communist government in 1989.
Ceausescu’s oppressive policies had banned abortion and contraception, while those without children were taxed. As a result, large numbers of children ended up in orphanages living in terrible conditions.
Previous studies involving the adoptees have shown they had marked cognitive difficulties as children — although these improved considerably into adulthood — while they also had high rates of conditions including attention deficit hyperactivity disorder (ADHD) and, as adults, high levels of anxiety and depression.
Writing in the journal Proceedings of the National Academy of Sciences, Sonuga-Barke and colleagues told how they carried out brain scans and other measures of 67 Romanian adoptees who had spent between three and 41 months living in severe deprivation as children. At the time of the scans the adoptees were between 23 and 28 years old.
The team also took brain scans from 21 adults of a similar age who had been born and adopted in the UK before they were six months old. The results revealed the Romanian adoptees had on average an 8.6 percent smaller brain overall than their UK peers. The team also found the size of the reduction was linked to the length of time spent in the Romanian orphanages: each additional month was linked to a 3cm3 lower total brain volume. “The more deprivation they had, the smaller their brains are,” said Sonuga-Barke.
The team’s analysis showed the smaller brain size explained the reduced IQ and, at least in part, the higher rates of ADHD found among the Romanian adoptees.
Prof Denis Mareschal, from Birbeck, University of London, said the study highlighted the importance of providing enriched environments in early infancy and childhood.
Source article: http://www.taipeitimes.com/News/lang/archives/2020/01/14/2003729181/2