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This is the 5th podcast for Memory & Mind News, a companion program to the Memory News Digest, a monthly newsletter put out by Memory Key dot com, a website devoted to providing information about memory and learning to help you achieve permanent memory improvement.

In this podcast, I will be discussing some of the news items that didn’t make it into the digest. References and links can be found on the website.

In the Digest I reported on a study extending the many reports that have made it clear that sleep consolidates procedural learning – that is, the learning of skills, of tasks that involve a sequence of movements. Although this effect is now clear, the question of whether or not it helps the principal type of memory – so-called declarative memory, which is our memory for information of all kinds, from remembering faces and what’s happened to us to remembering facts -- is still very much a matter of debate. But as I mentioned, a new study seems to have clarified the situation, and explained why the evidence has been equivocal. It took an investigation into the effects of interference to reveal the importance of sleep.

There were other reports this month that relate to sleep. One such study was investigating the effect of sleep deprivation on decision-making. The study involved 40 young healthy volunteers who lived in the lab for 6 days, during which they stayed awake for a 64-hour period. During this period they were given cognitive tests every 2 hours; their brains were also scanned in the morning and evening. The researchers found that working memory was not in fact affected after 36 hours without sleep – but only because other parts of the brain jumped in to compensate for the deterioration in function. After 60 hours however, their brains became unable to keep doing this, and performance started to decline. Perhaps even more importantly, the researchers found that even after 2 full nights of sleep, performance on all tasks still wasn’t fully recovered.

Bearing in mind the pervasiveness of sleep deprivation in American culture at least — I recently reported in my blog on a study showing that while people thought they were getting about seven hours of sleep nightly, they were really getting only about six hours — it’s perhaps salutary to note another study that was reported last month, demonstrating that cognitive behavioral therapy is better than drug therapy for short- and long-term management of insomnia.

The cognitive therapy involved weekly treatment sessions on sleep hygiene, sleep-promoting behaviors, relaxation training, and problem-focused education. After 6 weeks, total sleep time was similar in all groups, but slow-wave sleep (which is particularly important for feeling rested) had improved significantly in the cognitive group while declining in both the drug and placebo groups. At 6 months, total sleep time had continued to increase in the cognitive group (but not in the drug group), and overall sleep efficiency had also improved significantly.

To return for a moment to that study showing people sleep less than they think — the study found out something else interesting. The study involved 669 middle-aged Chicago residents, and significant racial and gender differences were found, with white women sleeping the most (6.7 hours), then white men (6.1 hours), then black women (5.9 hours) and finally black men (5.1 hours). The amount of time in bed was not that dissimilar; the problem lay in time taken to get to sleep, and how long sleep lasted. For example, while white women took some 13 minutes to get to sleep, black men took around 36 minutes.

Lest you think that some kind of racial characteristic is going on here, let us note that higher income was associated with more sleep. Several reasons are put forward as underlying these differences: more anxiety, noisier, less comfortable environments, more health problems.

But all I want to do is note that poorer sleep can be one more reason for poorer academic and IQ performance.

On which note, let us turn to a report on a new analysis of four national intelligence tests, indicating that the difference in scores between blacks and whites in the United States decreased by about a third between 1972 and 2002. The findings challenge the long-standing argument that the racial gap in performance on IQ tests is primarily genetic and therefore invulnerable to social change. An argument by the way that I have absolutely no time for. It seems glaringly obvious to me that whether or not there is a racial difference cannot possibly be answered until we have an environment where there are no differences in environment — in living environment, in cultural environment, in educational environment, in prenatal environment — for different racial groups (leaving aside the whole vexed question of what race actually is). That day is a long long way off. In the mean time, since we know beyond a shadow of a doubt, that academic performance and IQ are affected by a host of factors that we can do something about, how about we just concentrate on that?
Okay, rant over.

The study examined data that have only recently become available to researchers — data that included two or three groups of people that took the test at different times. Previous measures of the intelligence gap have all used localized populations tested only once. In the new analysis, all four tests reflected a similar gap in 1972 but indicated that blacks have since gained ground in IQ.

Here’s a couple of reports that bear on this. The Guggenheim Museum runs a program called Learning Through Art, in which artists visit schools. In a study of hundreds of New York City third graders, some of whom had participated in the Guggenheim program, and some of which hadn’t, it was found that students in the program performed better in six categories of literacy and critical thinking skills — including thorough description, hypothesizing and reasoning — than did students who were not in the program. However, the program didn’t help improve students’ scores on the city’s standardized English language arts test, which may, as the researchers suggest, be related to the fact that the standardized test is written while the study’s interviews were oral. Or of course it may reflect the fact that tests are not always good measures of anything but the ability to regurgitate whatever has been decided is the “appropriate” answer. That’s just a general remark; I have never seen this particular test.

Of course in the Digest I mentioned a report into the effects of PE classes. A point the researchers of that study made was that having the PE classes didn’t detract from academic performance — a point that only really makes sense in this context of how there’s been so much emphasis on the “basic” skills of literacy and numeracy, that other lessons are falling by the wayside. These studies (and don’t forget the many studies showing the value of learning music for language skills) point to the fact that there is more than one way of getting at a problem, and that indeed it seems likely that too much direct instruction of basic skills is counter-productive.

Okay, returning to our more general theme of environment and learning/intelligence. We know that poor nutrition early in life impairs development. However, poorly nourished children can undergo a period of accelerated growth once their diet improves, ultimately appearing normal as an adult.

A new zebra finch study has come out demonstrating that this compensation comes at a price. The birds who grew fastest when given a normal diet were slowest to learn. It's likely that resources normally dedicated to these pathways are diverted to support accelerated growth, shortchanging the co-opted pathway. Future study is needed to identify the exact underlying mechanism — something we need to find out if we’re going to learn how to manage growth and nutrition for low birth weight babies and avoid the costs associated with compensatory growth.

And before leaving the whole vexed question of intelligence and the ability to learn and the factors that affect these, here’s another study investigating gender differences. The story so far: increasing evidence suggests that, although men and women have similar intelligence, they don’t have the same brains. Now it’s long been knows that there are differences between men and women in verbal and visuospatial tasks — although what this means is of course hotly debated — but the difficulties of setting up a fair test have produced inconsistent results as to whether men and women actually use different parts of their brains. A new study has supposedly overcome these difficulties and confirms that men and women do indeed use different parts of their brains when processing both language and visuospatial information.
But the important point — and one that echoes the recent findings regarding intelligence — is males and females performed equally well, they just used different parts of their brains to get the tasks done.

Let’s end with something more frivolous, or weird. If you’ve read my article on the Mozart effect, you’ll know that this media-hyped effect of Mozart's music on intelligence is the result of a misrepresentation of a 1993 study that found that 10 minutes of exposure to a Mozart's Sonata improved performance on three spatial reasoning tasks — for ten to fifteen minutes. A result which in itself is not all that exciting (although certainly intriguing) and has moreover not been consistently replicated.

But people can’t let go of such a great idea — all you have to do is listen to some music to be smarter — so of course there’s still a thriving industry based on selling Mozart.

Anyway, this latest report is really weird. Apparently three labs in recent years have found that playing a Mozart sonata improves maze performance in rats and mice.

And why not, you say? We use rodents all the time in research, and we wouldn’t do that if there wasn’t a great deal of similarity between us and rodents. But there’s one area where we are definitely different, and that’s our senses. Rats and mice can't even hear much of Mozart's music. The pitches are too low for them.

So maybe it’s a case of researchers seeing what they want to see — and don’t mistake it, the myth of objective researchers is just that; that’s why we always seek replication of results; it’s the number of different researchers coming up with the same results that proves something, not one or two studies — or maybe there really is something going on there. But if so, we’re a ways off knowing precisely what it is.

And that’s it for this month’s podnews; I hope you enjoyed it.

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