Friday, November 19, 2010

How can neuroscience research help children affected by poverty?

The social issues roundtable at SfN this year entitled "Child Poverty and Human Capital: New Insights from Neuroscience," featured four panelists: three neuroscientists, Drs. Martha Farah, Sebastian Lipina, Helen Nelville, and one economist, Dr. James Heckman.

The main question discussed was how neuroscience research may be used to address neural cognitive and emotional problems which are associated with childhood poverty, especially in the third world.  Each panelist communicated his/her own research as well as other relevant work on the topic (a recent review can be found here).  For example, several studies have demonstrated that childhood poverty influences neural development and correlates with low socio-economic status ("SES") (typically based on income, material resources, education/occupation, violence, exposure to toxins, parental care, etc...) in adulthood.  This correlation is not surprising since children who are raised in poverty-stricken homes tend to have access to low-quality education, poor nutrition and other harsh environmental conditions.  The panelists also asked whether poverty ought to be measured in terms of family income and other monetary measures or by less tangible factors such as "quality of parenting."

Brain plasticity:
A property of the brain which must be taken into consideration when addressing these issues is its ability to be plastic.  In particular, different systems in the brain can adapt and strengthen/weaken their internal connections through different experiences.  Neuroscience research has discovered that, for some brain networks (e.g. visual or language system), early life experiences are critical, while other systems continue to develop later in adolescence and adulthood (e.g. executive center).  Thus brain plasticity allows us to be vulnerable as well as resilient depending on environmental influence.

Evidence (Sociological, psychological and epidemiological studies):
Research in humans and in animal models suggests that SES affects brain development by influencing factors such as prenatal environment, parent-child interactions and cognitive stimulation in the home.  Studies have demonstrated that intelligence (based on IQ tests) and educational achievement is lower in children living in poverty.  Interestingly, children from low SES homes also have relatively lower social and emotional intelligence.  Although most of these studies are correlational, there is causal evidence as well.  For example, causal links have been found between low SES homes and physical/somatic factors, environmental toxins and prematurity.  Discovering such causal links is crucial because government and policy-makers are guided and motivated by evidence which is based on rigorous scientific investigations.

Evidence (Neuroscience studies):
As opposed to sociological and epidemiological studies, neuroscience research can identify the underlying cognitive systems that are influenced by SES.  It can also shed light on the mechanisms, whose understanding may enable us to design specific interventions to prevent the effects of low childhood SES.  In general, the largest effect of SES are on language processing and moderate effects have been observed in working and declarative memory processing as well as spatial cognition and cognitive control.

Studies have shown effects of SES on vocabulary, phonological awareness and syntax.  There is a decreased specialization of language processing in the left brain hemisphere in children with low SES (Raizada, R. D. S. et al., Neuroimage, 2008).  Another study has shown that low-SES children do not recruit the prefrontal cortex attentional system to the same degree as higher-SES children (Kishiyama, M. M. et al., J. Cogn. Neuroscience, 2009).

Emotional and social:
A study of college students has revealed that low-SES is associated with an increase in amygdala response to angry faces (Gianaros, P. J. et al., Soc. Cogn. Affect. Neuroscience, 2008).

Economics and Policy:
The issue of "prevention" vs. "remediation" was also brought up during the social issues roundtable.  Today hundreds of billions of dollars are being spent on remediation - intervening in adulthood to alleviate conditions underlying low quality of life (e.g. depression, addiction).  Policy makers must determine whether it is in the government's best economic and moral interest to intervene later in life or prevent the negative conditions from ever taking place.  According to Dr. James Heckman, it is not a question of morals or ethical principles.  It would actually cost less if the government allocated funds on prevention by intervening very early in a child's life (i.e. early childhood education).  Thus a moral vs. cost tradeoff does not really exist in this case!

SES has been generally ignored in neuroscience, probably because of the difficulty of controlling its numerous components.  However, recent studies have initiated this endeavour, and now, many believe that SES may be understood by studying the underlying neural mechanisms.  Unfortunately, only a few studies have provided useful and robust results.  Therefore, future research is crucial to corroborate previous results and develop ideas of effective interventions.  By identifying the brain areas affected, we would be a great position to develop training programs (e.g. game-based strategies) which can target particular neurocognitive systems directly.

To learn more, visit Changing Brains

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