The genetics-solves-everything crowd is continuing to have an influence on society that threatens to set Americans' notions of equality back decades. I still believe these attitudes are cyclical, but it is always depressing and disturbing to be in the regressive part of the cycle, with no hint of change in sight. The target now of course is public education - always in the sights of extremists, whether it involves adding prayer, subtracting science, or the current fad, teaching kids their gender roles, as if society weren't taking care of all of these things adequately outside the classroom.

Dr. Leonard Sax's website is called "Why Gender Matters". His publications have such objective scholarly titles as "Reclaiming Kindergarten: making kindergarten less harmful to boys" (Psychology of Men and Masculinity, American Psychological Association, 2(1):3-12, 2001), which like his other writings set up an absurd dichotomy between boys and girls as if they are unrelated species. He claims that for boys, but not girls, kindergarten is "a series of alienating failures and humiliations" and implies it is thus the end of their academic careers. Many women competing for professional jobs (requiring extended education) with men would be surprised to hear that all males' spirits were crushed in kindergarten, given that they are still pretty much running society.

The problem with our educational system is not that "no one is teaching them how to be men and women" (from Sax's website) but that we are using blunt instruments, such as standardized testing, which saps what little autonomy teachers had in the classroom before NCLB. This means they are unable to address differences among individual students in development times of different skills. Yes, that variation exists, but using gender as the blunt instrument to guide education reform is even worse than using a standardized test. On top of it being a pointless exercise to assume anyone's academic strengths and weaknesses at a given age can be assessed using their appearance, it also reinforces so many stereotypes that so many of us had finally begun to move past, and furthermore gives them false "scientific" credibility. This type of "science" is no different from attempts a century ago to demonstrate through physical qualities that blacks were less intelligent than whites.

This blog has previously summarized the alarming trend of claiming genetic origin for every trait anyone can think of, and why the papers supporting these ideas tell us absolutely nothing. The problem of the other type of research cherry-picked by Sax to support his agenda is that it studies already-developed human beings. Anyone who has raised a child should understand the intellectual dishonesty of claiming that behavioral traits possessed by a baby or toddler are clearly genetic. Humans are social creatures, programmed from birth to learn from other humans how they should behave. That includes identification with a particular gender, and all the traits associated with it in a particular society. Brain development does not occur in a vacuum, but is affected by experience. Brain-scan differences even in a newborn can not be determined to be genetic, because the newborn's brain started developing nine months before.

Most important though, the differences found are minor and slight - meaning it is unlikely that they are biologically significant. From the Times magazine article:

Sax initially built his argument that girls hear better than boys on two papers published in 1959 and 1963 by a psychologist named John Corso. Mark Liberman, a linguistics professor at the University of Pennsylvania, has spent a fair amount of energy examining the original research behind Sax's claims. In Corso's 1959 study, for example, Corso didn't look at children; he looked at adults. And he found only between one-quarter and one-half of a standard deviation in male and female hearing thresholds. What this means, Liberman says, is that if you choose a man and a woman at random, the chances are about 6 in 10 that the woman's hearing will be more sensitive and about 4 in 10 that the man's hearing will be more sensitive. Sax uses several other hearing studies to make his case that a teacher who is audible to boys will sound too loud to girls. But Liberman says that if you really look at this research, it shows that girls' and boys' hearing is much more similar than different. What's more, the sample sizes in those studies are far too small to make meaningful conclusions about gender differences in the classroom.

Why is it now acceptable to use "science" to foster people's underlying prejudices about gender, but no longer about race? Apparently there is some sort of hair-splitting going on in the minds of these "scientists" that of course skin color and other associated traits tell you nothing about what is going on in someone's brain, we know that now, so forget about that. But different genitals, now that clearly must be correlated with brain function. Especially the genitals of pre-pubescent humans!

It is especially insidious that the idea being promoted is just a new version of "separate but equal", which as anyone knows who is at all familiar with history, means anything but. Sax's motivation is clear. He has been on a crusade for years to convince people that public education is biased against boys because most of the teachers are women. (Of course, who is responsible for that? Surely not the men who over the ages told women that the only profession they could have was teaching, since obviously it is such an undesirable job. Surely not the principals and superintendents who for some reason are still overwhelmingly male, and oversee overwhelmingly female teaching staffs. But I digress.) He does a clever job of convincing people that he cares about girls too, but this concern is nothing but pandering to get people to buy into his system of segregation.

It's truly a shame, because for completely opposite reasons, single sex classrooms in public schools can be a good idea. For instance, in the context in which many kids are more interested in what the kids of the other gender think of them than the academics going on in class, single-sex classrooms can remove a major distraction. Because it's a good idea for kids to learn to relate to the other gender socially, it seems that the best situation is some, perhaps not all, single-sex classes in coed schools. It also does help remove some teacher biases which have usually been documented to favor boys (not girls, as Dr. Sax claims) in their participation. But if, as Dr. Sax claims, the majority of schools going to single-sex classes are basing their new paradigm on his "genetics" theories, then we are in big trouble, because it will make many of the gender prejudices that have sunk below consciousness openly acceptable again.

Labels: brain, education, gender, genetics, statistics

A recent paper in Nature Neuroscience (Amodio, D.M., J.T. Jost, S.L. Master & C.M. Yee, 2007. Neurocognitive correlates of liberalism and conservatism. Nature Neuroscience 10:1246-1247) has been presented as far more controversial than it is - although surely the authors knew they would ruffle a few feathers with their study.

Here is the abstract:

Political scientists and psychologists have noted that, on average, conservatives show more structured and persistent cognitive styles, whereas liberals are more responsive to informational complexity, ambiguity and novelty. We tested the hypothesis that these profiles relate to differences in general neurocognitive functioning using event-related potentials, and found that greater liberalism was associated with stronger conflict-related anterior cingulate activity, suggesting greater neurocognitive sensitivity to cues for altering a habitual response pattern.

The authors give citations to support the claim that "Across dozens of behavioral studies, conservatives have been found to be more structured and persistent in their judgments". I have not read those papers but for the purpose of this commentary will assume that there is indeed scientific support for this conclusion. Though their experimental procedure is clearly one accepted by neuroscientists, the rest of us are expected to take at their word that "responsiveness to complex and potentially conflicting information relates to the sensitivity of this general mechanism for monitoring response conflict." Here is the test:

Go/No-Go task. On each trial of the Go/No-Go task, either the letter "M" or "W" was presented in the center of a computer monitor screen... Half of the participants were instructed to make a "Go" response when they saw "M" but to make no response when they saw "W"; the remaining participants completed a version in which "W" was the Go stimulus and "M" was the No-Go stimulus; assignment to either version of the task was random. Responses were registered on a computer keyboard placed in the participants' laps. Each trial began with a fixation point, presented for 500 ms. The target then appeared for 100 ms, followed by a blank screen. Participants were instructed to respond within 500 ms of target onset. A "Too slow!" warning message appeared after responses that exceeded this deadline, and "Incorrect" feedback was given after erroneous responses.

There is no way here to confirm the authors' interpretation that results obtained on this test are explained by liberals' higher sensitivity to "cognitive conflict" at the level of political decisions, but it is an interesting idea, because it appears both from cited research and probably anyone's observations that conservatives tend to have more of a black-and-white view of the world, while liberals tend see more shades of gray. ("Liberal" here is used in its traditional sense, not the currently distorted media code word for "left wing." Indeed, hard left-wingers are arguably no more liberal than hard right-wingers.)

The paper wisely does not attempt to determine whether this brain-function correlate or political leaning comes first (and they certainly do not at all imply that the response of liberals to this test is "smarter," despite William Saletan's defensive interpretation). It should not be assumed that just because the brain shows a certain physiological response to a stimulus, this response is genetic. Just as the accumulation of memories alters pathways in our neurons, a response such as this may be "learned" by the brain as well, based on experience.

Of course, some people become more conservative with life experience. Here are three competently untested hypotheses for why this can happen (given the conclusion that liberals see more complexity in the world than do conservatives).

1) Often, people become more fiscally conservative as they grow older. Fiscal conservatism is, however, a separate issue from that of "cognitive conflict." Those emphasizing the long term will be more fiscally conservative than those who prefer to live in the moment, which is more correlated with age group than with social or political views. Certainly over the last three decades political conservatives have shown no sign of being fiscal conservatives.

2) Someone who has suffered a traumatic, life-affecting event, such as a death or lost job, or whose loved ones have, might find it simpler to have an easily defined target to blame. Bad economic times had a lot to do with the growth of the Ku Klux Klan.

3) There is really no way to form economic or social policy that takes into account all the complexities that a diverse group of people will experience. Because it is simpler to craft legislation that does not take so many complexities into account, policy makers - and the pundits living in the same beltway world, away from the real one, and those listening to the pundits - come to believe we live in a simple world with easily definable boundaries. Such was one of the major reasons the SCHIP legislation failed. The idea that there is a particular income cutoff, above which every American family can afford health insurance without regard to any other parameters, was heavily promoted by the conservative opposition to the bill.

A corollary of the last point is that people who are well-off financially are usually conservative not because they are fiscally conservative (many of them are not), but because it is emotionally least complicated to believe there is a simple reason why they are wealthy while so many others are poor, e.g. they work hard and poor people don't.

There also could be positive physiological feedback loops in the brain which strengthen a tendency to fall one way or the other in one's view of the world. While some people do change their political views, most people actually seem to become more strongly liberal or conservative over time. It is an unfortunate by-product of our social tendency to form opposing groups that once we have formed an opinion about a person or topic, our views become more confirmed because we accept observations that support them, and ignore or rationalize observations that do not support them.

To be truly objective in his or her views, a person would need to be constantly reassessing prior beliefs based on every bit of new information received. Why are humans, many of whom pride themselves on their over-awing logical arguments, not that way at all? Perhaps it is because as social animals, we are always creating rules to live by, and the simpler those rules are, the easier our lives are, in many ways. Even with our large brains, it would get too difficult to navigate socially, as we need to, if the rules were too complex.

Labels: brain, empathy, humans, politics, sociality

At the risk of sounding heartless, the death of Alex the Talking Parrot last week leaves some of us, who have worked in the same department with Dr. Irene Pepperberg, a bit relieved. It was certainly bordering on irritating when those of us studying animal behavior using less glamorous species were putting in the long weekends to raise our sample sizes in order to make our work acceptable to the reviewers of actual science journals, while Dr. Pepperberg cranked out dozens of papers in such publications as the Journal of Comparative Psychology and Language Sciences, and was recruited to various appointments in science and psychology departments at the University of Arizona, MIT and Harvard using data from a single, often disagreeable, bird.

Certainly Dr. Pepperberg played the media like a fiddle, making her attractive as a "researcher" because of all the publicity she drew to that one bird. She laments Alex's passing in many respects, surely, but partly because after over 25 years of training, Alex still had not had the chance to show the world what a genius he was:

Alex could pull together a few simple concepts. Show him a group of objects and he could tell you, "What color is wood and four-corner?" or, "What shape is paper and purple?" Dr. Pepperberg was hoping to train Alex to spin his own recursions, informing her that the nut was "in the blue cup that’s on the tray" or "in the yellow box on the chair."

"I wish we had gotten further," Dr. Pepperberg wrote in an e-mail message. "We were just beginning to get him to designate things like 'in' and 'on.' "

Fortunately, though, he did last long enough to have a human's entire career built around him. Perhaps the two other parrots Pepperberg is training will achieve greater heights of language skill than Alex did. Still, one cannot help but wonder why Dr. Pepperberg never seemed to last more than a few years at a given institution. Perhaps it was her uninterest in interacting with her colleagues, which seemed to indicate that she had nothing of value to learn from such an interaction. Perhaps when the novelty of her research wore off at a given institution, the realization finally dawned that her career's work has added little of value to our body of scientific knowledge.

Sample size is a critical issue in science. Data from one individual (or even three individuals) are marginally useful at best because there is so much variation among individuals. What if an alien came to earth and collected data about the linguistic abilities of humans based on conversations with only Franklin Roosevelt? What if its data were based on conversations with a high school drop out with an IQ of 60? (or President Bush? Sorry, couldn't help that one.) Its conclusions would be quite different in the two cases.

Another problem with teaching animals English in order to draw conclusions about how their brain works is that we are testing them in a context that has no evolutionary relevance for their species. Ecologists and evolutionary biologists were interested in Alex's data, given more study about African grey parrots social structure in their natural habitat - because "language" is all about communication with others of one's same species. Unfortunately, although Dr. Pepperberg gave lip service to exploring such research directions in the future when that is what her colleagues wanted to hear, she never seemed much interested in actually pursuing that avenue (and a glance through her long reference list does not indicate any publications devoted to the parrots in the wild).

So people can argue forever about Alex's true abilities, parsing his every word and knowing glance, but what biologist can really muster any interest in the conclusion of that discussion? It will tell us nothing about Comparative Psychology, because all we have is an inadequate sample size about an animal living in a cage in a lab, interacting mostly with humans. But perhaps the Language Scientists love all the hullabaloo for inspiring passionate discussions about whether and how any species other than humans can use language. Perhaps training Alex had some purpose after all, but it was not science.

Labels: behavior, brain, statistics

Although evidence is purely anecdotal, it appears these days that most children sleep a lot less than children of generations past. The majority of parents I encounter (certainly not all) seem to put their children to bed around the time they go to bed, which means a lot of kids out there may be getting only eight hours of sleep or less. Data presented in Weissbluth (2003), however, show that although total sleep per day declines with age until 14 years (in teenagers it creeps back up again), the median amount of sleep needed by children never drops below about 9.5 hours by this age. At 4, median sleep time is 12.5 hours, and the 10th percentile is 10.5. So although 10% of 4-year-olds out there may need less than 10.5 hours of sleep, one encounters many more than that who are getting less.

There seems also to be some correlation between sleep disorders and ADHD (attention deficit-hyperactivity disorder) (Gau et al., 2007; Hora das Neves 2007), although the nature of this correlation is not yet well understood, if it is even real (Sadeh et al., 2006). Medical studies relying on self- (or parental-) reported data, which many of these seem to be, are unreliable at best.

There are, however, suggestions by some that some of the people labeled as ADHD may instead be suffering from poor sleeping. This may be caused by sleep disorders such as sleep apnea. But most articles on the subject, even those advocating treatment of sleep disorders before treatment of the ADHD itself, seem to assume that sleep problems are one of the symptoms of ADHD.

What if the reverse is true, that years of sleep deprivation has caused ADHD? Weissbluth (2003) seems to be one of the few authors suggesting this link. All of us know that in the short term, sleep deprivation makes people irritable, unable to concentrate, and even often hyperactive. What if kids are growing up sleep-deprived for years? Might that not be a cause of sleep disorders?

What's worse is that the popular drug for controlling ADHD, Ritalin, is a stimulant, and kids on it sleep less than those on an alternative non-stimulant ADHD drug, atomoxetine. (Sangal et al., 2006). Are we making our kids lives worse in the long run by addressing only the short-term behavioral problems?

It can be difficult for parents to sleep-train their children, and many never do. Their child is in an endless cycle of exhaustion followed by a crash. The easiest way to sleep-train a baby is to put her down and let her cry until she falls asleep. Most kids will only cry for a long time for 2-3 nights, and then they understand that it is their sleep time, and they learn to put themselves to sleep. Failure to teach a child to get to sleep on his own can lead to a lifetime of sleep problems. It is crucial for the developing brain to get an adequate amount of sleep, which is when the brain processes new knowledge and experience. Babies and small children have a lot of new information to process, and they need to sleep a lot, often for longer than they are awake. It is not a stretch to imagine subtle (or not so subtle) developmental brain damage occurring in children who are chronically sleep-deprived because their parents will not force them to go to bed before they are exhausted. Obviously ADHD is a complicated issue, and it is likely to have many causes, ranging from genetic to environmental. But the first question any parent of a hyperactive kid should ask is, does my child get enough sleep?


References

Gau, S.S.F., Kessler, R.C., Tseng, W.L., Wu, Y.Y., Chiu, Y.N., Yeh, C.B. & Hwu, H.G. (2007) Association between sleep problems and symptoms of attention-deficit/hyperactivity disorder in young adults. Sleep 30:195-201.

Hora das Neves, S.N. & Reimao, R. (2007) Sleep disturbances in 50 children with attention-deficit hyperactivity disorder. Arquivos De Neuro-Psiquiatria 65:228-233.

Sadeh, A., Pergamin, L. & Bar-Haim, Y. (2006) Sleep in children with attention-deficit hyperactivity disorder: A meta-analysis of polysomnographic studies. Sleep Medicine Reviews 10:381-398.

Sangal, R.B., Owens, J., Allen, A.J., Sutton, V., Schuh, K. & Kelsey, D. (2006) Effects of atomoxetine and methylphenidate on sleep in children with ADHD. Sleep29:1573-1585.

Weissbluth, 2003. Healthy Sleep Habits, Happy Child. Ballantine Books, New York.

Labels: ADHD, brain, health, humans

Is mathematics an emergent property of sociality? I posed this intriguing question to a mathematician colleague, who is also an evolutionary biologist, and he said yes. The question came up because I have argued that rules are actually a social construct; a solitary species needs few or no rules governing its interactions with other individuals of its species, because other than mating or occasional territorial conflict, it has almost none. Individuals in social species, by contrast, are completely dependent on rules to survive and reproduce, because interactions with other members of the species are constant, and determine standing within a social group, and thus generally reproductive success.

Most evolutionary arguments applied to humans are tenuous, because of cultural complexities that overly our basic biology. Complicating the picture further, aberrant behavior (that which does not comply to a given social norm) is also probably more common among humans than among other social animals, because 1) we have chemical treatments that suppress some symptoms of such conditions, 2) we have easy access to addictive products which our brains did not evolve to cope with, such as drugs, junk food, slot machines, etc., and use of these can lead to self-destructive behavior, and 3) many aberrant people are smart enough to overcome or disguise their problems enough to fit in somewhat. So, there are many ways in which humans seem to get away with behaving in socially maladaptive ways, without suffering reproductive consequences, as other social primates probably would.

However, we did evolve as a social species, and much of our behavior is indeed a legacy of that evolutionary history. The playing of games is an example. Games are all about rules. Kids love learning new games, because their brains are wired to learn rules -- particularly rules for navigating in real society, but an artificial society with artificial rules will do. Whether it is sports or war games or pin-the-tail-on-the-donkey, humans love games. Games with complex rules are more fun to learn for many of us, but those with fairly simple rules but complex strategy, such as Go or hearts or chess, usually capture the most active minds. It is our love of rules that make us despise the referee who makes a bad call. In our minds, if a rule is broken, the entire game should be void.

It seems that mathematics is universal, a truth that existed before humans and that they discovered. But to humans at least, mathematics is also all about rules, and perhaps the way that we perceive mathematics is filtered through our obsession with rules. We all learned them at the beginning of every school year for a decade. "Addition and multiplication are commutative. The transitive property says that if a=b and b=c, then a=c. The distributive property says that a * (b + c) = a * b + a * c" and so on. If you take higher level math classes in college, you discover that there are other mathematical systems with different rules; for instance, matrix multiplication is not commutative. So math is indeed a world of many rules that apply one way in one context but another way in a different context, very much like the rules of social interactions -- for example, it is inappropriate to wear a bikini at the opera, but just fine at the beach.

Although many would protest the truth of the statement, humans are wired for math. (If you hate math, it is not that you are "no good" at it; it is because the way it was taught to you made it painful and boring. This is a persistent problem that will likely never be corrected on a large scale, because of the vicious cycle of elementary school teachers who dislike math and barely get through it in college, go on to teach it poorly, cause their students to dislike it, and so on.) The interesting question is, would, or could, an intelligent solitary species have developed math? Some would say the question is completely moot because only a social species would have evolved brains as large as ours, because sociality requires a larger brain to navigate the intricacies of social interactions, in addition to the basic needs of finding food and mates and defending oneself. It is perhaps a chicken-and-egg question. But what is no question is that complex rules govern sociality, human brains are therefore wired to learn and use rules, and mathematics is a system of rules. Mathematics, very much like religion, is likely a byproduct of our success as a social species.

Labels: brain, evolution, humans, mathematics, sociality

Moms, you don't need to send your second sons to remedial school just yet.

Once again, Science Magazine is a tool of publicity hounds who trumpet their incredible breakthroughs in press releases, knowing that almost nobody will read - let alone understand - the fine print and discover that their claims have all the foundation of a sand castle.

Petter Kristensen and Tor Bjerkedal (2007. Explaining the relation between birth order and intelligence. Science 316:1717) managed to squeak a one-pager in this week that gives even those of us trained to read scientific papers a run for their money. However, if one delves into the online supplements to the article, and an accompanying paper also newly available(1) it becomes clear that the results are biologically meaningless, despite the media's ever present desire to milk them for controversy. This is why:

First and foremost, this is yet another paper that uses an enormous sample size (over 250,000) to support its conclusions. Those who do not fully grasp the nature of statistics often believe that this makes results more credible, when in fact, it makes them less so. This is because in huge sample sizes, any tiny difference between groups is amplified to the point where it is likely to be statistically significant. However, statistical significance does not necessarily imply biological significance, especially when large sample sizes are required to identify a statistical effect. The authors of these papers themselves give the best demonstration of the fallacy of this technique when they cite a previous Science paper(2) that reached exactly the opposite conclusion using 400,000 Dutch men. If they repeat the study tomorrow using a different huge population, they could easily find the results reversed again.

If birth order has no correlation with IQ at all, then in randomly selected Norwegian family, there is a 50% chance that the first son has a higher score than the second son. My statistician colleague did some rough calculations based on the data in the Science paper, and concluded that it shows that in a randomly selected family, there is a 52% chance the first son scores higher than the second son. The statistical standard for biological significance in most contexts is 95%. For a first son to have a 95% chance of scoring higher than a second son, the average difference in IQ points would have to be 80. (As far as I know, there is no data showing that second sons are more likely to be retarded.)

In addition, the Norwegian soldiers did not take a standard IQ test, which has a population mean of 100. They took a test given by the Norwegian military which gives single-digit scores of 1-9, with a mean of 5. The scores are therefore much less precise than those from an IQ test, and a difference of 3 IQ points after the data transformation corresponds to a difference of 0.25 point on the Norwegian test. If two brothers both have a score of 6, which one is a quarter point smarter?

The media love these stories and will continue to broadcast them, analyze them, and give people complexes about them forever. But it is disheartening that Science, an internationally respected journal that scientists throw elbows to get published in because of the instant fame it brings, is in it purely for the publicity as well. People should no longer assume that a paper in Science must be actual science.


(1)Bjerkedal T., Kristensen P., Skjeret G.A., and Brevik J.I., 2007. Intelligence test scores and birth order among young Norwegian men (conscripts) analyzed within and between families. Intelligence doi:10.1016/j.intell.2007.01.004 (in press)

(2)Belmont, L., and Marolla, F.A., 1973. Birth order, family size and intelligence. Science 182:1096-1101.

Labels: brain, humans, statistics

Recently we were advised to take lots of folic acid to help prevent Alzheimer's. (Of course, that study, when scrutinized, showed itself to be highly flawed.) Now, we are supposed to avoid folic acid like the plague because it will cause cancer:

High doses of folic acid do not prevent precancerous colon polyps in people prone to them and may actually increase the risk of developing the growths, a new study finds.

This study (Cole et al., 2007. Folic acid for the prevention of colorectal adenomas: A randomized clinical trial. JAMA. 297:2351-2359) actually finds a lot of non-statistical differences between groups of about 500, one taking folic acid supplements for several years, and one not. The only probable real difference in the groups (considering the large number of comparisons they made) was in those people with 3 or more adenomas (pre-cancerous growths) found 6-8 years after the study began.

One issue muddying the water in the study, which was not the fault of the authors, was the addition of folic acid supplements to quite a lot of the American food supply by the FDA, starting in 1998, two years after the study began. This presumably helped to obscure potential differences between the treatment and control groups because all were essentially taking folic acid supplements, with the treatment groups taking more. Additionally, the supplemented amounts were more than double (1 milligram) the "recommended daily value" of 400 micrograms - and that is ignoring the folate they were getting from whatever plants they were eating, and piles of folic acid they started getting in their diet after the FDA's intervention. Six years is a long time to be pounding your body with a huge excess of any one nutrient.

The mainstream media love a more sensational representation of the latest medical news, however:

Cancer patients should discuss taking vitamins with their doctors, and anyone over 50 who takes vitamins should have a colorectal screening test, said Cornelia Ulrich of Seattle's Fred Hutchinson Cancer Research Center, who co-wrote an accompanying editorial.

Apparently, suddenly all our doctors are going to have all this knowledge about what supplements their patients should take, because of this one paper telling us that infusing our systems with one particular compound for six years is probably a bad idea. (And cancer doctors aren't exactly who I would pinpoint to be nutrition fairies - most of the cancer patients I have known would have been better off without being poisoned slowly by doctors using the euphamism "chemotherapy.") Shouldn't everyone (who can afford it) over 50 get a colorectal screening test? Colorectal cancer is one of the easiest cancers to prevent by snipping off the adenomas within the colon. Who cares about vitamins?

Our obsession with supplements has gotten entirely out of control. Instead of taking policy steps that would help people consume good foods to obtain the nutrients our bodies need at levels to which they are adapted, our government and media imply there is always an easy fix by taking some supplement or other in absurd dosages. Certainly they give lip service to eating a balanced diet, but government policies actually subsidize, and thus promote, the production of cheap processed foods that are little but empty calories. On the NIH page linked to above explaining the folic acid food supplementation, it is actually stated, after a list of the easily obtained, unprocessed plant foods that contain natural folate (as opposed to the synthetic folic acid):

The March of Dimes Birth Defects Foundation warns women not to rely on these foods for enough folic acid to prevent serious birth defects in their future babies (March of Dimes 1997).

We know the March of Dimes is focused solely on preventing every possible birth defect, but doesn't this seem a bit extreme? Certainly it is possible, and in some societies routine - to give birth to a healthy baby without taking a lot of supplements; yet we are issued a "warning" to take supplements, implying an "or else."

Fortunately, a subset of Americans is taking back control over their diet, by creating more farmer's markets, and supporting organic, and more important, local food production so more of us can eat better without resorting to cheap junk. Unfortunately, the medical community is still all about fixing us after there's something wrong. That's why even when considering prevention, they think in terms of medication, rather than the inculcation of lifestyle changes which are known to keep us healthy in the first place. Certainly in this world today the former way of thinking is much easier to promote. This has led to a plethora of studies on drugs and supplements, giving people substances our bodies are not adapted to, or abnormal amounts of substances our bodies do normally encounter, with results that have really not been very helpful in the long term. As one doctor says:

"Right now it would not be appropriate to blindly go forth and further increase the levels of folic acid without better understanding the potential risks," Mason said. "And whether we continue folic acid fortification should be an open debate over the next few years."

Amen to that. How about instead we spend some money finding a way to make it a lot easier for people to eat what they are designed to eat?

Labels: brain, health, humans, vitamins

Encephalon, the brain carnival, is up now. Find out why hamsters like viagra.

Labels: brain, carnivals

A recent article about research supporting a neurological (= biological) basis for altruism panders to the alarmist view that behavior with an identifiable biological basis precludes personal responsibility, and could throw our criminal justice system into an uproar.

The first statement that shows an ignorance of sociobiology and evolution:

The results -- many of them published just in recent months -- are showing, unexpectedly, that many aspects of morality appear to be hard-wired in the brain, most likely the result of evolutionary processes that began in other species.

Why is this unexpected? In social animals, such a biological basis for morality would absolutely be expected. This is because morality governs social interactions, so animals who have evolved in the context of sociality have a biological need for it. Altruism is related to empathy, without which we cannot interact socially because we need a mechanism for assessing what another person is thinking or feeling. Those without empathy, such as autistics, are lost in the maze of unspoken rules that govern interpersonal interactions. Altruism is a way of acting on empathic information.

...some wonder whether the very idea of morality is somehow degraded if it turns out to be just another evolutionary tool that nature uses to help species survive and propagate.

The idea that "morality is somehow degraded" because it has a biological basis really has no logic to it, but it is typical of those who confuse morality with religion. Perhaps the idea is analogous to someone we like doing something nice versus someone we do not like doing it. In the latter case we assume insidious motives because we do not believe the person is truly being altruistic. But the mistake there is that there is no such thing as pure altruism, as research shows. Either altruistic acts cause us to receive tangible benefits, such as increased standing in a community, or if anonymous, provide us with pleasure (Moll et al., 2006).

Of course morality and altruism are complex neurologically because human social interactions are complex. But a biological explanation for moral behavior does not indicate a lack of need of philosophers or even religious thinkers who study moral behavior such as altruism. Humans are faced with ethical decisions nearly every day, and it is not always clear what is the altruistic way to respond, even if that is our goal. That is why religious advisors, analysts, and advice columnists are not automatically out of a job just because automatic brain function reveals our options. Our brains often do not make obvious the decisive course of action, that is, the course of action having the most positive or least negative social consequences, in the balance. Social consequences are a real biological phenomenon, because decisions affecting an individual's social standing often affect that of an entire family, which shares genes.

For example, there is the potential problem of revealing or not revealing a friend's indiscretions, such as an extramarital affair. In the short term, revealing the truth might be bad for the social group, as bonds are broken. But in the long term, the earlier such a truth is revealed, the quicker wounds may heal and the social group rebuilt. Such a decision is necessarily affected by social norms of the community, which are of course extremely variable among societies.

The article points out that "a number of experiments such as the one by Grafman have shown that emotions are central to moral thinking." Of course this is true. Grafman and his colleagues (Moll et al., 2005) make it clear that moral reasoning is a complex process that uses both reasoning and emotional centers of the brain - there is no one specific brain structure that dictates morality, but rather a series of structures that must interact in a complex way to produce a moral decision. The role of emotion is understandable because a major purpose of emotion is social navigation; for example, laughter is a way of making a social connection with another person. Solitary-living animals have no need for emotions such as love, anger, envy, pride, etc., because feeling these or acting on these invariably involves the establishment, maintenance, or alteration of a social relationship.

While several brain structures interact to produce moral reasoning, those involved can be identified specifically because specific brain damage has predictive effects on moral behavior (Moll et al., 2005). For example, damage to the prefrontal cortex at an early age prevents normal development of moral reasoning. Such people often have short-term, self-centered responses to moral dilemmas, because they have no sense of the social consequences of their actions. A different region of the cortex, the superior temporal sulcus, is required as well because it is a center of social perception, i.e. empathy, which is also required for normal moral reasoning. The limbic system, a center of basic emotional drives, also affects morality because behavior such as aggression is controlled by this area, and can become uninhibited when parts of the limbic system become damaged. Functional MRI studies also have indicated activity in the orbitofrontal cortex (behind the eyes), the anterior temporal lobes, the insula, and the anterior cingulate cortex in people processing moral dilemmas posed to them.

The claim that these discoveries mean that "society has to rethink how it judges immoral people" (according to Adrian Raine, a USC neuroscientist) is absurd. There is a minimum standard of behavior that is acceptable in a society, and this minimum exists whether or not you are psychopathic (= brain damaged in a way that impairs interpersonal interactions due to lack of empathy). If some people are physically unable to make correct social decisions, it does not mean we must treat them as equals. Serial killers are psychopaths, and whether their brain damage is physical or developmental, they cannot be allowed to move freely in society because they have no internal constraints against killing. We lock them up so that they cannot damage society further. Most people would agree that a similar situation holds for pedophiles - there seems to be increasing evidence that most are incapable of being "rehabilitated," which is not surprising; their psychopathy is likely due to brain damage - which again can be physical or developmental - that cannot be repaired. Damaged people must be isolated from society because the structure of society must be protected for the sake of the non-damaged majority.

J. Grafman says, "Some of the questions that are important are not just of intellectual interest, but challenging and frightening to the ways we ground our lives. We need to step very carefully." Not at all. This information is simple and reasonable when understood in terms of maintaining a functional society.

An interesting moral phenomenon in humans involves the altruism of helping someone near and dear to you versus helping people in distant countries that you will never visit. The neuroscientist/philosopher Joshua Greene, interviewed in the article, gets the implications of this wrong:

"We evolved in a world where people in trouble right in front of you existed, so our emotions were tuned to them, whereas we didn't face the other kind of situation," Greene said. "It is comforting to think your moral intuitions are reliable and you can trust them. But if my analysis is right, your intuitions are not trustworthy. Once you realize why you have the intuitions you have, it puts a burden on you" to think about morality differently.

Yes, we evolved in a non-global world, and our knowledge of the plights of people around the world sets humans apart from other social animals. But that is not the point. What matters is that any type of altruism affects one's standing either in society, or to oneself. Our higher reasoning ability convinces us that faraway starving children are as important as the starving children next door - even as our emotions tell us otherwise - but this does not make our intuitions untrustworthy, it just adds potential complexity to the moral decisions we make. If one is a member of a church, for example, where such generous behavior is valued, it increases or maintains one's social standing to give to the needy in faraway places, it makes sense to do it. For many people, "charity begins at home" is an acceptable societal standard, and thus there is no burden to think about morality differently. Undamaged brains can still rely on their moral intuitions, and navigate their social world successfully.

Of course the different details of morality across cultures require us to be flexible in their moral reasoning. The social brain must adapt to local social conditions to successfully reproduce. This creates difficulties in a globalized world in which we not only are aware of the different moral values in different societies, but people from those different societies interact daily, not only in person, but probably more important these days, over the internet. To use an extreme example, people from societies that support individual rights for women have worked hard to stop what to us are sickening cultural practices such as female genital mutilation. Any Western woman is horrified by the practice with good reason - it not only is such an extreme example of oppression of women by men, which goes against our stated values (values that were hard won and still being fought for even in our "enlightened" society), but the long term health consequences are often dire. Yet efforts to eliminate the practice are often derailed by the women of those cultures themselves, because if they do not accept the ritual mutilation, they will be rejected by their society (and will not reproduce successfully there). It is nearly impossible to end such traditions by force. The values rejecting them must be inculcated in enough of the local population to the point where it becomes socially acceptable not to undergo the mutilation.

A similar example closer to home is the explanation of why most battered wives return to their husbands over and over again, contrary, it seems, to all reason. But in the cultures (and subcultures) in which wife-beating is common, breaking the cycle is so difficult because if a woman leaves her husband she often must give up her entire social group as well (and she often cannot fathom that it would be possible to become part of another social group, simple as that may seem in the abstract). Going it alone under such circumstances is contrary to our very nature as social beings.

It is completely natural for everyone to believe that their society's cultural norms are superior to everyone else's, because they know from experience that following those cultural norms make them successful. Of course though, if the same behavior is transferred to a society with different cultural norms, the result can be disaster. It is this naive sense of superiority (also held by most religious groups) that creates solutionless predicaments such as the current one in Iraq.

References

Moll, J., Krueger, F., Zahn, R., Pardini, M., de Oliveira-Souzat, R. & Grafman, J. (2006) Human fronto-mesolimbic networks guide decisions about charitable donation. Proceedings of the National Academy of Sciences of the United States of America, 103, 15623-15628.

Moll, J., Zahn, R., de Oliveira-Souza, R., Krueger, F. & Grafman, J. (2005) The neural basis of human moral cognition. Nature Reviews Neuroscience, 6, 799-809.

Labels: behavior, brain, empathy, humans, morality, sociality

For a multitude of fascinating articles about the brain, click here for the latest edition of Encephalon at Ouroboros.

Labels: brain, carnivals

A Science Times story about the condition known as "dissociative amnesia" today jarred a memory I have of one chapter of a friend's extremely colorful life. My friend is in her 80's and was married four times; only the final marriage lasted for a significant time, and only it could be described as fairly normal. Her first marriage story can only be described as astounding.

My friend "Annie" got married for the first time near the start of the U.S. involvement in WWII. Her husband became a soldier, but never made it overseas - he was involved in a train accident in the U.S. and suffered brain damage and a long recovery. How Annie coped during this period with no money and a couple of small children is a story itself (it never occurred to her that she could get some assistance from Uncle Sam), but eventually her husband recovered enough to work for the U.S. mint as an engraver after the war. Life went on for a few years but Annie wasn't entirely happy because her husband was starting to show, in her mind, undue aggression toward her oldest son. She was concerned that sometime he might go too far and hurt her son, but didn't know what to do about it.

The problem ended up solving itself, because one day Annie's husband never came home from work. No one had a clue where he was. She tried for awhile to locate him but the effort was a bit halfhearted because in truth, she was relieved for her kids' sake. She still found it quite odd, though, that he would leave for good without even a word to her. She eventually obtained a divorce due to her abandonment, but his disappearance remained a mystery - no friends or family members knew where he went.

Something like 20 years or more passed before the mystery was solved. The ex-husband's sister was walking along in Seattle one day, and was shocked to see him on the street. She grabbed him and started talking, and it was only at that point that he himself remembered anything of his life 20 years before. The day he disappeared, he had simply forgotten everything about his life at the time, to the point of not even knowing where he was or how to get home. I know no details of how he dealt with his situation at the time, but at the time he was rediscovered, he had built an entirely new life with a wife and kids without remembering a thing about his original life until the day he saw his sister, when it came back to him.

Eventually, he travelled to visit Annie and her (fourth and final) husband, but Annie's oldest son refused to talk to him; Annie could not convince him that his father had abandoned him through no fault of his own. By that time enough years had passed that Annie, happy in her current family, was philosophical and did not feel any emotional baggage in meeting him; she did so mainly out of curiosity, and understood that what had happened was some sort of strange by-product of the train accident. She and her husband continued a friendly correspondence with her ex and his family for a number of years.

I had never heard of this type of amnesia before or since hearing this amazing story from Annie, until reading the above article. I'm sending her a copy! Here is the
Merck manual description of the disorder.

My main reaction is that this must happen more than is recognized, because Annie's ex was able to build a whole new life, and never would have known what happened to him if he hadn't happened to run into his sister - imagine the odds of that! I do not know if he ever told a doctor about his problem or not, but he coped with it rather well. Perhaps it would be harder in today's world where ID numbers are so ubiquitous. But if I ever hear again about someone abandoning their family without a trace, I would have to wonder...

Labels: behavior, brain

I used to give blood regularly, but am now forbidden because I lived for months at a time in England from 1998-2001, where BSE (Mad Cow disease) emerged in the mid-1990's. I have scoffed at this rule; from everything that I understood, Britain has far greater monitoring of beef than the U.S. True, BSE has been found in thousands of British cattle and very few North American cattle, but then again one is unlikely to find such a sneaky pathogen if one is not looking for it. Unfortunately, the U.S.D.A., which exists to serve agribusiness interests, rather than those the American public which pays for its existence, has at best dragged its feet on increased testing of cattle, and at worst actively has prevented those who would test on their own initiative from doing so.

The U.S.D.A. itself has drastically curtailed its BSE testing in the last few months. The agency presents no data on BSE testing on its website after August, 2006. However, the new policy is spelled out based on the detection rate from the previous sampling:

Since the enhanced surveillance program began, USDA has sampled more than 759,000 animals and, to date, only 2 animals have tested positive for BSE under the program. Both cases were in animals born before the United States banned the practice of feeding recycled ruminant protein to other ruminants. In line with USDA policies, neither of the affected animals detected under the enhanced surveillance program nor the imported cow detected in 2003 entered the human food or animal feed chains.

Based on the wealth of information gained during both the enhanced surveillance program and BSE surveillance conducted in the United States in the 5 years prior, USDA recently concluded that the prevalence of the disease in this country is extremely low, less than 1 case per million adult cattle, and that the most likely number of cases is between 4 and 7 infected animals out of 42 million adult cattle. Our analysis was submitted to the scrutiny of a peer review process, and the expert panel agreed with the appropriateness of our assumptions and the factors we considered, as well as with our estimate of BSE prevalence.

The new testing protocol is as follows:

The ongoing BSE surveillance program, which will sample approximately 40,000 animals each year, will continue to sample the cattle populations where the disease is most likely to be found. The statistically valid surveillance level of 40,000 is consistent with science-based internationally accepted standards. This level allows USDA to detect BSE at the very low level of less than 1 case per million adult cattle, assess any change in the BSE status of U.S. cattle, and identify any rise in BSE prevalence in this country.

The targeted population for ongoing surveillance focuses on cattle exhibiting signs of central nervous disorders or any other signs that may be associated with BSE, including emaciation or injury, and dead cattle, as well as nonambulatory animals.

As they say, the methodology is based on standard science. But does that really protect our food supply? The unknowns about BSE are disturbing, and unfortunately the testing protocol is based on assumptions that may not be true because we still know so little about this disease.

Britain's beef supply is not currently as safe as I thought, as this 2002 report spells out in detail:

BSE: risk and regulation
A case study paper commissioned by the National Consumer Council
Prepared by Patrick van Zwanenberg & Erik Millstone
Science and Technology Policy Research, Sussex University

It turns out there are still many questions out there about how animals are contracting BSE and how to prevent it:

Indeed, to date, there have been 14 cases of BSE in animals born after August 1996; they constitute an anomaly which remains inexplicable. The mechanisms by which those animals were infected are unknown... It is therefore likely that some animals under 30 months will be sub-clinically infected with BSE and will be entering the human food chain. We cannot know how many animals under 30 months might be incubating the disease, however, because the existing short-term tests can only detect infected animals shortly before clinical symptoms appear, and the UK government has chosen not to conduct any sort of test for BSE on animals entering the human food chain. In 2001 there were 761 reported cases of BSE in the UK... A further 335 cases were also reported in that year from the, as yet uncompleted, active surveillance programme;... but in the summer of 2001, the European Commission's Food and Veterinary Office noted that "[a]s active surveillance is practically not performed [in the UK], it has to be assumed that the BSE incidence for GB has to be seen with a considerable degree of uncertainty."

This means that testing only sick and downer cattle doesn't necessarily cover the possible infected animals. Clearly we have done some things that have helped reduce the risk considerably, for example not allowing cattle to be fed mammal by-products any more. Yet there are loopholes; from the FDA itself: "In August 1997, FDA established a regulation that prohibits the use of most mammalian protein in the manufacture of animal feeds for ruminants." Apparently though it is still legal to feed chickens mammalian protein. BSE may not pass this way, but we know so little about it we cannot say for sure.

And some rules put in place in the 1990s have already been relaxed:

The U.S. Food and Drug Administration today published several amendments to the July 2004 interim final rule, "Use of Materials Derived from Cattle in Human Food and Cosmetics," that will allow the use of certain cattle-derived material in human foods and cosmetics...

As a result, FDA is amending the rule to allow use of the small intestine in human food and cosmetics, provided that the distal ileum has been removed. The U.S. Department of Agriculture is publishing today a similar amendment to its interim final rule on BSE.

The amendments also clarify that milk and milk products, hides and hide-derived products, and tallow derivatives are not prohibited for use in human food and cosmetics.

Is there any other reason for this than pressure from industry? Shouldn't the U.S. government be erring on the side of caution in the case of such a potentially devastating health issue? Those infected with BSE take decades to show their symptoms. This is not a situation where a couple people will drop dead and the FDA will say "whoops, better change that rule" as a result.

As a final note, among the real unknowns about spongiform encephalopathies is that despite what is reported in the popular press, it is clear from official and scientific documents that it is not known without doubt that prion proteins are the proximate cause. It is certainly the currently most popular idea, and most scientists are studying prion proteins based on this assumption, but there are still peer-reviewed papers in respected journals which assert alternative hypotheses, for example:

Manuelidis, L. 2007. A 25 nm virion is the likely cause of transmissible spongiform encephalopathies. Journal of Cellular Biochemistry 100:4.

The transmissible spongiform encephalopathies (TSEs) such as endemic sheep scrapie, sporadic human Creutzfeldt-jakob disease (CJD), and epidemic bovine spongiform encephalopathy (BSE) may all be caused by a unique class of "slow" viruses. This concept remains the most parsimonious explanation of the evidence to date, and correctly predicted the spread of the BSE agent to vastly divergent species. With the popularization of the prion (infectious protein) hypothesis, Substantial data pointing to a TSE virus have been largely ignored. Yet no form of prion protein (PrP) fulfills Koch's postulates for infection. Pathologic PrP is not proportional to, or necessary for infection, and recombinant and "amplified" prions have failed to produce significant infectivity. Moreover, the "wealth of data" claimed to support the existence of infectious PrP are increasingly contradicted by experimental observations, and cumbersome speculative notions, Such as spontaneous PrP mutations and invisible strain-specific forms of "infectious PrP" are proposed to explain the incompatible data. The ability of many "slow" viruses to survive harsh environmental conditions and enzymatic assaults, their stealth invasion through protective host-immune defenses, and their ability to hide in the host and persist for many years, all fit nicely with the characteristics of TSE agents. Highly infectious preparations with negligible PrP contain nucleic acids of 1-5 kb, even after exhaustive nuclease digestion. Sedimentation as well as electron microscopic data also reveal spherical infectious particles of 25-35 nm in diameter. This particle size can accommodate a viral genome of 1-4 kb, sufficient to encode a protective nucleocapsid and/or an enzyme required for its replication. Host PrP acts as a cellular facilitator for infectious particles, and ultimately accrues pathological amyloid features. A most significant advance has been the development Of tissue Culture models that support the replication of many different strains of agent and can produce high levels of infectivity. These models provide new ways to rapidly identify intrinsic viral and strain-specific molecules so important for diagnosis, prevention, and fundamental understanding.

I am not advocating a specific position on this at all; clearly, the current scientific consensus does not support this view, and I do not have the expertise in this area to judge. But I recommend that anyone who believes this is an important issue read up on it at the U.S.D.A. site and the British consumer report. In the meantime, I will be continuing my policy of avoiding factory feedlot beef (and not only because of the risk of BSE). I will also continue to update current research here because of my own interest in the topic.

Labels: brain, environment, statistics, USDA

Neurophilosophy recently posted on current research on why our brains have trouble paying attention to several stimuli presented in quick succession. While getting at the mechanisms behind these processing "bottlenecks" is an ongoing endeavor, it has actually been known for some time that what some people proudly describe as their ability to "multitask" is actually no such thing. Humans (and probably other animals as well?) are actually terrible at this, and the conceit that we are good at it is actually responsible for loss of productivity. So it's not exactly clear why an article trumpeting this as news has appeared in the popular media. Nevertheless, the article motivated me to read up a bit more on the topic. I focused on the recent paper: Sigman, M. and Dehaene, S. 2006. Dynamics of the central bottleneck: Dual-task and task uncertainty. Plos Biology 4:1227-1238.

The authors make a few relevant observations. Referencing what has been previously known:

A dynamic trace of central limitation is ... manifested at a slower time-scale (seconds to minutes) in the inability to rapidly switch the control processes that harness together independent processing modules ... This effect is most evident in task-switching paradigms, which show, using a variety of different experimental manipulations, that reaction times increase when participants change between different task configurations...

Typical result - multitasking slows us down. But why? Here is one of the authors' conclusions:

Although central processing of task 2 can be executed immediately after central processing of task 1 has been completed, the outcome of task 2 cannot be executed until the system has disengaged from the previous response-setting mode.

This means that in addition to the lag in performing a second task, due to the need to finish the previous task first, there is an added lag during which our brain has to shift gears from the first task to the next. So if you add up all the time one task takes if you focused on it completely to the time the second task takes if you focus on it, it will be less than the time you take doing them both together. Thus, as the example in the Times article suggests, shifting your attention back and forth from the road to your cell phone introduces dangerous delays in your driving response time. This probably explains why the accident rate for cell phone users is said to be equivalent to that of drunk drivers, who also suffer from impaired response time.

But what do a few seconds here and there matter for a situation in which we are not in control of a lethal weapon hurtling 75 mph down the highway? The problems go beyond time delays; there are impacts long term memory as well. For those of us in education, the problems introduced by task-switching too often are obvious. The standard university schedule of four to six classes every day, mostly lectures, pretty much could not be a worse way for students to learn. Many professors may not like this characterization; obviously we went through this system and did well enough to become professors ourselves. The problem is, the great majority of our students are not like us. They are not riveted to a lecturer's every word because they find the topic so fascinating, thinking about it in depth after class. No, most of our students attend our lectures, do their best to listen, and probably most of them genuinely understand the material at the time it is presented. When they do lousy on our tests, however, we blame their inability to apply themselves, and certainly that is a factor. Unfortunately, our system is setting up all but the brightest and hardest-working students to fail, when it comes to long t