Tuesday, October 28, 2014

Brain plasticity -- why should intelligence be an exception?

We live in an age that demands we multitask if we're going to get everything done that we need to do.  Answering email, picking up the children, submitting grants for every deadline, getting in 30 minutes of exercise everyday, eating right, keeping up with the literature -- so much pressure.  Fortunately someone's got our backs, and we can now answer email on one screen at our treadmill desks and work on that grant proposal on another, all while we have lunch.  So much easier, so much time saved.

But wait, psychology tells us that, despite appearances, we can't multitask after all, we can't do two cognitive things at once.  Instead we're 'task-switching', reading then speaking, writing a paragraph then answering the text from the child we forgot to pick up. So tread milling, eating and emailing we can do but tread milling, eating, emailing and writing a methods section we can't.

Unless we're musicians.  A new paper in Cognitive Science ("Musical Training, Bilingualism, and Executive Function: A Closer Look at Task Switching and Dual-Task Performance," Moradzadeh et al.) reports that musicians are better at task-switching and 'dual-tasking' than non-musicians.  Task-switching is just what it sounds like, the ability to switch between tasks, and the speed and ease with which this can be done is what was measured.  Dual-tasking is the ability to do two or more things at once. There must be a reason this isn't just 'multi-tasking' but I don't know what it is.

I'm also not sure what constitutes a 'task'.  Indeed, how many tasks is reading music, with all the separate bits it involves (remembering which key has 5 flats, how long to hold a black flagged note compared with an empty oval, what that marking over the final note means, all the Italian notations telling you how to play the piece, turning notes on a page into a melody, keeping time, etc.) or playing the horn, with all the separate bits that involves (how to blow into the mouthpiece, how to press the keys, which fingering to use for each note and how to do that, how to synchronize your breathing with your fingers to get a note, how to play loudly or softly, playing in tune, all while remembering what each of the conductor's hand movements signifies, and staying in time with the players around you)?  Some of these tasks get relegated to muscle memory after enough practice, certainly, but much of musicianship still involves cognition.

Anyway, the researchers compared the ease with which a group of 153 bilingual and monolingual musicians and non-musicians switched between tasks or accomplished more than one at once.  These were apparently standard psychological tests, with task switching involving tracking numbers on a computer screen, and dual-tasking involving tracking a white dot while looking at flashing letters, while being asked to note when an X appears.
Results demonstrated reduced global and local switch costs in musicians compared with non-musicians, suggesting that musical training can contribute to increased efficiency in the ability to shift flexibly between mental sets.... These findings demonstrate that long-term musical training is associated with improvements in task switching and dual-task performance.
The researchers point out that there can be 'far transfer effects' of training or experience on cognition. This is a well-studied area of psychology, and it's known that many hours of things like physical exercise or video-gaming can affect how we think, or remember, and so forth.  So, that something as complex as musical training might affect other mental skills isn't a surprise.

And, it has long been known that longterm musical training has effects on brain structure, including on sensorimotor and auditory areas, but on grey matter as well (references here).  And, London taxi drivers are known to have larger hippocampi, related to spatial navigation, than London bus drivers who spend as much time driving.  Multilinguists have denser grey matter in brain areas related to language and communication than do monolingual people.  And so on.

This is all overwhelming evidence for brain plasticity.  It beats me why anyone would insist that intelligence is an exception, hard-wired, and not at all contingent upon experience.


Anonymous said...

IQ, and the g factor, is largely immutable. The mainstream scientific literature has proven this many times over. For example, Plomin's publications on the subject.

Ken Weiss said...

Ah, thanks. So that nails it! Early experience, environment, resources, and all that other fluffy stuff that has distracted science is put to rest. And study, practice, calisthenics, and so on are a total waste of time since, obviously, you've either got it or you don't. I think even Plomin would add at least a few caveats to the iconic worship of 'intelligence'.

Anne Buchanan said...

Even if we assume that IQ is real, and that IQ tests measure what the strongest proponents claim, the IQ of a fetus can't be measured, nor that of a young infant. Therefore, it's impossible to know that IQ is the same from the time whatever it is first develops to the time of the first IQ test. Given what we know about how the brain grows, that neurons and synapses respond to environmental stimuli in utero and in early infancy, I would suggest that early experience is integral to the molding of whatever it is IQ tests are measuring. That is, it's not immutable.

Anonymous said...

Hey Ken Weiss.

Do you know of what Evan Charney is up to lately?

Last I got was the Chasing ghosts article on GCTA.

Anonymous said...

Interesting that you object to the fact that IQ is a thing, despite the fact that most scholars have agreed that the g factor and IQ are not only real but that they measure something important. I will refer to a paper by Plomin in which he demonstrated that heritability of the IQ of lower SES individuals does not change at all. adoption studies also prove that with the finding that lower SES individuals into higherSES environment does not improve IQ or heritability. I will further refer to the books The Blank Slate, by Steven Pinker, The Nurture Assumption, by Judith Rich Harris, and G is for Genes, by Kathryn Asbury & Robert Plomin. All these books prove, citing the mainstream literature, that environment and upbringing or plasticity have very little effect on the personality and behavior traits and outcomes of any individual. As Turkheimer wrote, everything is heritable. "Genetic determinism" is the null premise.

Anne Buchanan said...

Clearly you haven't spent much time at our blog.

Ken Weiss said...

g-whiz! As Anne says, now that you've enlightened us with definitive proof that everything is pre-determined at conception, you can go back to the blogs that express your point of view.

Anonymous said...

It's not I that who has proven anything, it's the literature. I don't understand why you object to that.

Anne Buchanan said...


I am guessing that you aren't an evolutionary biologist, or even a scientist because what you're expressing is belief in dogma rather than a measured evaluation of the evidence about IQ and intelligence and how it fits in evolutionary context. Scientists shouldn't be in love with their hypotheses, they should doubt them and shake them up and rattle them around.

Given what is known about plasticity of the brain, as it responds and adapts to experience, and given that one of the most fundamental characteristics shared by the simplest and most complex organisms is adaptability, so it seems unlikely to me that intelligence will turn out to be a static, genetically determined thing that a lot of people are hoping to find. And of course there are many kinds of intelligence, too.

We know that there are large genetic influences on cognitive ability, but as with most complex traits, these tend to be at the extremes of the distribution. Of course there are genetic influences on the middle of the distribution, on how we solve problems or whatever it is we're calling intelligence, but I think it will turn out as with many other complex traits that there are many genes involved, and that what they produce is a cognitive environment that responds to experience.

Search on "intelligence", "complexity", "complex traits", "plasticity", "genetic determinism" and so on on this blog for more on these issues.

And, don't believe everything you read. Including here. Question.

Anonymous said...

Strange though, from some of the authors this guy is talking about... heritability.



Why do you allow comments from people blatantly lying?

Also environment is heritable as shown by epigenetics... and the most crucial environment is in the mothers belly(which is not accounted for). Thats 80% or so of the brains growth environment not accounted for.

Anne Buchanan said...

Thanks. Intelligence is one of those subjects that reveals how much belief is involved in science. We don't recognize when we're wearing blinders. Intelligence is a hard subject to look at dispassionately, as we would try to understand the effect of genes vs environment on fungal coloration, say. The last thing science should be is dogmatic, but too often, culture and politics make it so.

Ken Weiss said...

And heritability is an immensely misunderstood measure. This is not the place to go over that once again, except to say that it is not a measure of an individual's inherent pliability or inherited 'destination', etc., and at most is a (frequently problematic) measure of the trait one decides to study in a particular population's current context.