Stress Inhibits Brain's Ability to Grow

Travoltus writes "Dr. Professor Elizabeth Gould claims to have shown that, with marmoset primates, stress causes the brain to switch to survival mode in which it thinks only about survival; it simply does not invest new cells in other, more complex thought processes. Dr. Gould also suggests that poverty has an adverse effect on the brain. Dr. Gould is a Princeton researcher who concentrates on studying adult neurogenesis, a phenomenon that, 20 years ago, most scientists believed did not occur."

Comments

What about other people?

[Kawahee]

What about the other people that thrive on working to deadlines and with demanding workloads? I'm sure there are many professions that are very stressful that require people to keep themselves 'sharp' and alert at all times.

Or is there a difference between positive and negative stress against the brain?

Re:What about other people?

[east coast]

I meant the stress that people thrive on. 'Non-consequential' stress, where if you screw up it's not the end of your world.

Well, I see your point but being in a situation you "enjoy" is not necessarily beneficial. Even those who enjoy the fast paced life may not be in a good position as far as overall physical and mental health.

Re:What about other people?

[pvt_medic]

stress has many different meanings for different cultures and by different groups. Typically in medicine stress is looked at as something that will stimulate a physiological response. Stress is a needed part of our lives. without stress muscles would not grow, with out stress we would not learn, etc. The challenge is how much stress can one tolerate. Many people find that they become more effective when they are "stresses" the body is reacting to this stimuli, but eventually there is a point where even the most adaptive body will not be able to adquately respond to the stress.

Re:What about other people?

[happyemoticon]

I'd characterize myself as the kind of person GP is talking about. However, I wouldn't characterize what I thrive on as stress, but focus and structure. Nothing makes me happier in the morning than knowing that I can go to work and focus intensely on something all day long, and go home with a sense of accomplishment that I finished it on time. When I have to multitask or I'm working on several non-essential projects at once, I feel dithery and lazy.

I say this is different from stress because when I was in college, I had several friends - we were all sort of higher-achieving humanities students - who would get very stressed. They would do things like stop cleaning their apartments, eat nothing but potato chips for a week, sleep two hours a night, and generally fall apart as human beings around finals time.

Re:What about other people?

[Sir Holo]

What about the other people that thrive on working to deadlines and with demanding workloads? I'm sure there are many professions that are very stressful that require people to keep themselves 'sharp' and alert at all times.

It depends what you would call "stress."

As a child, did you go to bed hungry?
Did you grow up only ever knowing one parent?
Were you stopped by cops on the street and searched, from as young as 10 years of age?
Were you taken away from your parents at an early age?
Did you, as a child, have to hide in the bathroom to get away from a day-and-night party your mother was having, just to get a little bit of your homework done?
Do you come from a "broken" home?

These things are the "stress" the researcher is looking at. The marathon sessions in the stacks at the library, or the projects working under deadline, that guys like us take on, are not that - they're taking on challenges. From TFA:

For the last several years, she and her post-doc, Mirescu, have been depriving newborn rats of their mother for either 15 minutes or three hours a day. For an infant rat, there is nothing more stressful. Earlier studies had shown that even after these rats become adults, the effects of their developmental deprivation linger: They never learn how to deal with stress. "Normal rats can turn off their glucocorticoid system relatively quickly," Mirescu says. "They can recover from the stress response. But these deprived rats can't do that. It's as if they are missing the 'off' switch."

And a little bit more from TFA:

On a cellular level, the scars of stress can literally be healed by learning new things. ... As predicted, putting marmosets in a plain cage--the kind typically used in science labs--led to plain-looking brains. The primates suffered from reduced neurogenesis and their neurons had fewer interconnections.

However, if these same marmosets were transferred to an enriched enclosure--complete with branches, hidden food, and a rotation of toys--their adult brains began to recover rapidly. In under four weeks, the brains of the deprived marmosets ... demonstrated significant increases in the density of their connections and amount of proteins in their synapses.

The realization that typical laboratory conditions are debilitating for animals has been one of the accidental discoveries of the neurogenesis field.

Re:What about other people?

[dr.badass]

I'm sure there are many professions that are very stressful that require people to keep themselves 'sharp' and alert at all times.

The difference here is between "challenge" and stress. There is basically a channel between challenges that are so insignificant as to provoke boredom, and challenges that are overwhelming and produce stress and anxiety. Between those are challenges that we can handle and are rewarding as a result.

People who thrive when working to deadlines do so because it isn't especially stressful, and may in fact be less stressful for them than having no deadlines. It might be exhausting work, but if it were truly stressful they would probably be less productive as a result. It seems from this article that real stress may actually prevent one from learning and keeping sharp, so the image of the perpetually exhausted but highly productive student or worker as a shining example of success in action is wrong more often than not.

Re:What about other people?

[drmike0099]

Although this is almost a philosophical question, from a scientific standpoint there's very little difference (that I've ever heard of) between positive and negative stress. They all create the same reactions in the body. It probably has more to do with chronic vs. acute stress. Positive stress (e.g. getting a new job and having to change your lifestyle to accomodate it, having a new baby, heading off to college) are typically more of an acute nature and therefore usually don't have the negative side effects. Conversely, poverty, joblessness, diseases, and certain other negative stresses are typically very long-term in nature. We know that long-term stress is worse, but that people can even decompensate with short-term stress, and there are a lot of people who have very bad negative reactions even with positive stressors. Lots of psychology mixed into that, but at a high level it's true.

As for people who function at different baseline stress levels, I can relate one study I know of. They looked at people's reaction after a disaster (I forget which one, an earthquake I believe) and what they did in the immediate aftermath. Some people shut down completely and did nothing. Most got more active and began doing things at a higher level. Some people, normally not active and not classic "leaders", began directing the activities of others in a very effective manner. The end result was a curve that was developed (x axis was stress, y axis was functionality) and it showed a slow upslope as stress got higher, most people performed at a higher level, but at the highest level there was a cliff-like drop off, where people all of a sudden ceased to function at high stress loads.

The theory that came out of that (and having gone to medical school and operating in exactly the environment you describe where people "choose" demanding workloads, one that I think has face validity) is that individuals have different personal ways of moving along that curve that correspond to their own personal tolerance for stress. Someone who can't handle stress would fall off the end very quickly, and you could say is already operating at their highest point. Someone who can handle a lot of stress is almost impossible to push high enough to get over that cliff, and you can dump more and more stress and they simply keep handling it. That latter group actually get bored in low stress environments and can feel their personal functionality decline, and therefore avoid them (I'm one of those people). Vacation is often so boring I start to get depressed (which in itself is somewhat of a depressing thought!).

The leap from marmoset to man

[nystagman]

Interesting, but with few exceptions, humans are not marmosets.

There is a bit more happening in my brain than in a marmoset's.

Re:The leap from marmoset to man

[TeacherOfHeroes]

There is a bit more happening in my brain than in a marmoset's.

Maybe theres more going on in your brain, but I didn't get the impression that thats really a factor here. It doesn't seem to be the amount of activity thats in question, but rather the ways in which animal brains works.

Would you say that your brain is so different from the brains of other animals that they don't share basic characteristics?

How often do you hear about experiments done on mice; do you stop and point out that mice are nothing like people each time?

Re:The leap from marmoset to man

[Clover_Kicker]

> There is a bit more happening in my brain than in a marmoset's.

Extraordinary claims require extraordinary proof.

Re:I am guessing that

[Pantero Blanco]

The article actually goes into that.

"The social implications of this research are staggering. If boring environments, stressful noises, and the primate's particular slot in the dominance hierarchy all shape the architecture of the brain--and Gould's team has shown that they do--then the playing field isn't level. Poverty and stress aren't just an idea: they are an anatomy. Some brains never even have a chance."

Now, I don't think that poverty alone would cause the stifled neurogenesis they're talking about, but if you combine it with a lot of the other stressful things that tend to come along with poverty (crime-filled environment, fractured/broken families, poor education), that might do it.

Different kinds of stress...

[benjamindees]

I would say the difference is that there are kinds of stress that are self-induced, and there are kinds that are externally induced.

Most of the people I've known who thrive on stress are dealing with stress that is completely self-induced, from lawyers to students striving for high marks. Whereas the kinds of stress that the study seems to deal with, group status, annoying sounds, uninteresting environments, are all external and, more importantly, uncontrollable by the subject. That's also the case with post-traumatic stress disorder, for example. It isn't the stress per se, but the lack of ability to influence the cause of the stress, that likely causes damage.

Sports would be another example of self-induced stress. There is really little consequence in winning or losing, but pushing yourself can be beneficial.

So, on the other hand

[JanneM]

So, if you're free of stress your brain will grow, on the other hand. And the more you relax, the more it grows. Your head gets heavier, which makes it all the harder to get off the couch, making you relax for even longer, creating a positive feedback loop.

And as the skull is of fixed size, it means the brain gets denser and denser, until, in a paroxysmic cataclysm (or a cataclysmic paroxysm; the data is a bit fuzzy here), the earth is destroyed as ten million couch potatoes all have their brains collapse into black holes after a week-long Tonight Show marathon.

Dangerous stuff, this science thing.

Not a forgetting pill

[Mprx]

You're talking about propranolol, which is a non-selective beta blocker. It does NOT make you forget events, only emotions. If taken after a traumatic event you will still remember all the details of the event, but not how you felt at the time. It's not a amnesia pill.

Re:I am guessing that

[Marxist Hacker 42]

But that is *exactly* what the article is suggesting: that under survival stress, primate brains going all the way back to the marmosets concentrate their learning entirely on subjects that help them survive and *nothing* else. This explains the phenomenon of "street smarts" in poor urban human populations, where somebody who completely failed at school and is unable to read nevertheless is able to survive, but wastes all their money on alcohol, drugs, and TV.