Growing the Brain

In a previous blog I described a study that suggested creative activity encourages brain growth. Yesterday Nature Magazine published the results of another study that looked at brain development. This one linked income level to infant brain size.

Carried out by two researchers, Kimberly Noble from Columbia University and Elizabeth Sowell from LA’s Children’s Hospital, the study showed that infants from lower income families suffer a reduction in brain size. The implications of this study are that income disparity may have life-long, potentially irreversible consequences for children. These consequences go beyond the obvious disadvantage of diminished opportunity.  Even if at some point opportunity is equalized, children from low income homes may never be able to optimally exploit it.

Most of us are familiar with the nature/nurture debate.  Essentially, this discussion weighs the influence of environmental factors such as parenting, neighborhood and schooling against inherited traits. The Nobel/Sowell study, if it holds up, invalidates the debate. According to the study, nature is not a fixed element that can be juxtaposed against environment; it is a function of environment.

The observed effect of income level on brain size is so marked that even within lower income groups, variations of a few thousand dollars result in brain size disparity. If confirmed, the results of the Nobel/Sowell study ought to have a profound effect on the political dialogue that centers on economic equity.

Of thirty-three OECD countries,Chile, Mexico, Turkey, the United States and Israel were the five with the greatest income inequality.  That inequality may translate into millions of lifetimes of relative disadvantage.  Expand the focus of the results globally and a vast population, much of the world in fact, suffers that relative disadvantage.

It is true that we all want our children to maximize the potential with which nature has endowed them. But what if that potential is not fixed by nature? What if potential is at least partly a man-made artifact, a consequence of political and economic policies that perpetuate income inequality?

The authors of the Children’s Hospital/Columbia study are careful to explain that they don’t know exactly which factors influence brain size in infants.  The researchers guess the factors might be the usual suspects: nutrition, exposure to toxins, poor social stimulation. They suggest that tinkering with manageable factors during gestation and afterwards might have a beneficial influence.

However, it seems to me that the researchers pull back from the obvious remedy: close the income gap. This prescription, though obvious, is one that many people will find ideologically unpalatable.  Whenever wealth distribution is discussed there’s inevitably talk about freedom and choice. Which begs the question, what choice is given to an infant who lies in a crib with a destiny diminished by low income? What freedom does that infant have to forge a successful future?

Of course, there’s a larger issue than the individual tragedy of lost potential.  There’s the societal cost.  Children with less potential become adults who are less able. That is not in anyone’s interest, no matter their income level.

brain development
Credit for this image goes to Van Essen Lab(Washington University in St. Louis), in collaboration with Terrie Inder, Jeff Neil, Jason Hill, and others. The image illustrates human cortical development through gestation and into adulthood.

Salk or Sabin Polio Vaccine?





salk sabin vaccines picture

By A. G. Moore

The following is adapted from the Rhythm Prism publication Jonas Salk.  Although Jonas Salk was written with young readers in mind, there’s a lot in the book that may be informative to more mature readers.  For example, until I researched this book, I didn’t understand why the Salk or Sabin vaccine would be used in specific circumstances. Now I do understand: each vaccine has different risks and benefits

Adaptation from Jonas Salk:

Both the oral and injectable forms of the polio vaccine have been in use for more than fifty years. This has given the global community enough experience to understand risks and benefits of each.

Since the Sabin vaccine uses a live, though weakened virus, there is a slight chance that vaccination will actually give someone polio. This has happened in a small number of cases. Because of this risk, the Sabin vaccine was discontinued in the US and only the Salk is administered.

However, there is also a risk from the Salk vaccine. With the Salk vaccine, a very weak immunity is produced in the gut. If someone who has been vaccinated is exposed to wild polio, there is the possibility that the wild virus will multiply in the gut. Though the vaccinated individual may not become ill with polio, they can shed virus in their excrement. This shed virus then becomes a source of contagion for others in the community.

Because of the way the Sabin and Salk vaccines work, they are generally used in different places. If there is good vaccine coverage in an area, and most people have immunity to polio, then the Salk vaccine is used. This is generally considered safer because the vaccine cannot make the individual sick, and virus shed in excrement will not be dangerous to others who have been vaccinated.

On the other hand, if a polio vaccination campaign is conducted in an area where there are many unvaccinated people, the oral vaccine might be considered preferable. With the oral vaccine there is no risk of shed virus infecting unvaccinated people.  However, the risk remains that in a small number of cases, someone may actually contract polio from the vaccine itself. Not only can these people become ill, but they can infect others who haven’t been vaccinated.

One more consideration in the selection of vaccines is cost. Giving the Salk vaccine is about five times more expensive than giving the Sabin vaccine. In areas where resources are scarce, this is an important factor.

Polonium in Cigarettes

cigarette smoke smash

Last week I was researching material for a new book, Marie Curie.  Madame Curie, I learned, was like many very successful people: absolutely determined and stubbornly undeterrable.  Although she was not allowed to study because she was a woman and she was Polish,  she earned several advanced degrees.  She could not find a laboratory, did not have money for heat or food, and yet she performed groundbreaking experiments.

Marie Curie won two Nobel prizes, the first person ever to do so in two categories.  She was the first female professor at the Sorbonne and the first woman to win a Nobel prize.  She was also the first person to operate a mobile x-ray unite in a war zone.

So what does all of this have to do with polonium in cigarettes? Marie Curie discovered polonium and radium.  She knew they were radioactive; she knew they could burn skin, treat cancers and kill bacteria.  But somehow she never acknowledged that her beloved radioactive elements could be harmful to her health.

Marie Curie, and her daughter Irene, died of cancer.

Millions of people smoke.  Most of these people understand in some vague way that they shouldn’t smoke, but the threat they perceive seems distant.  Perhaps if they knew clearly what some scientists and all cigarette manufacturers know, then these smokers might grasp the risk that cigarettes pose to them.

Cigarette smoke contains polonium, the same polonium that Marie Curie discovered and named more than a hundred years ago. The amount of polonium in cigarettes varies according to the region where tobacco is grown.  US cigarettes definitely contain detectable amounts.

So, when a smoker takes a good puff and inhales, along with all the other things in the smoke that might harm, there is a dose of polonium–radioactive, cancer-causing polonium.  A good long puff on a cigarette delivers that polonium directly to lung tissue.

I think that’s something people ought to know.


Rhythm Prism’s compact book on Marie Curie, polonium, radium and radioactivity:

marie and atom 5 cover smash site

Available in print,

on Kindle


and through other eBook vendors