By Alexandra Sifferlin
The rich really are different, at least when it comes to their brains. In two separate studies, researchers found that experiencing poverty in early childhood is linked to smaller brain size and less efficient processing of certain sensory information.
Previous work suggested that poverty can contribute to compromised cognitive function and low performance in schools, but using imaging, researchers have documented measurable changes in the brain tied to poverty.
In one study, published in JAMA Pediatrics, children who grew up in impoverished households showed smaller white and grey matter in their brains compared with those who had more means — these make up the density of nerve connections between different parts of the brain. The less wealthy kids also developed smaller hippocampus and amygdala regions, which are involved in regulating attention, memory and emotions.
According to the researchers from Washington University School of Medicine in St. Louis, the smaller brain regions may be due to the increased stress and anxiety that these children experience growing up in families where finances are tight, and therefore parental support and interaction with children suffers.
In the second study, published in the Journal of Neuroscience, scientists at Northwestern University, in Illinois, connected lower maternal education, a common symptom of poverty, to poor processing of sound in the brains of children raised in lower-resource environments. The researchers found that adolescents whose mothers had less education were more likely to register more varied and noisier nerve responses when hearing speech than those whose mothers had more schooling. That response, according to previous work, could translate into poor reading skills. The scientific team suspects that the lack of constant verbal interaction between mother and child could be one factor in the noisier brain responses to speech, since such back-and-forth can prime a still-developing brain to isolate and recognize speech more efficiently. Other data established that children in higher-income families are exposed to 30 million more words than those in lower-income families where parents have less education.
The good news, however, is that the effects may be reversible. Families don’t chose poverty, but changes in caregiving, especially during early childhood, could avoid some of the physical changes the scientists measured. “By studying socioeconomic status within a neuroscientific framework, we have the potential to expand our understanding of the biological signatures of poverty,” said Nina Kraus, professor of neurobiology, physiology and communication sciences at Northwestern University and an author of the second study, in a statement. “And a better understanding of how experiences shape the brain could inform educational efforts aimed at closing the socioeconomic achievement gap."