Posts tagged ‘memory’

September 3rd, 2008

Why Our Brains Do Not Intuitively Grasp Probabilities

An excerpt from an article by Michael Shermer, Scientific American:

The reason that our folk intuitions so often get it wrong is that we evolved in what evolutionary biologist Richard Dawkins calls “Middle World”—a land midway between short and long, small and large, slow and fast, young and old. Out of personal preference, I call it “Middle Land.” In the Middle Land of space, our senses evolved for perceiving objects of middling size—between, say, grains of sand and mountain ranges. We are not equipped to perceive atoms and germs, on one end of the scale, or galaxies and expanding universes, on the other end. In the Middle Land of speed, we can detect objects moving at a walking or running pace, but the glacially slow movement of continents (and glaciers) and the mind-bogglingly fast speed of light are imperceptible. Our Middle Land timescales range from the psychological “now” of three seconds in duration (according to Harvard University psychologist Stephen Pinker) to the few decades of a human lifetime, far too short to witness evolution, continental drift or long-term environmental changes. Our Middle Land folk numeracy leads us to pay attention to and remember short-term trends, meaningful coincidences and personal anecdotes.

June 28th, 2008

Plastic Brain Outsmarts Experts

Training can increase fluid intelligence, once thought to be fixed at birth

Illustration showing the memory storage area of the brain with a nerve network.

Training a person’s working memory may increase his or her general intelligence.

Can human beings rev up their intelligence quotients, or are they stuck with IQs set by their genes at birth? Until recently, nature seemed to be the clear winner over nurture.

But new research, led by Swiss postdoctoral fellows Susanne M. Jaeggi and Martin Buschkuehl, working at the University of Michigan in Ann Arbor, suggests that at least one aspect of a person’s IQ can be improved by training a certain type of memory.

Most IQ tests attempt to measure two types of intelligence–crystallized and fluid intelligence. Crystallized intelligence draws on existing skills, knowledge and experiences to solve problems by accessing information from long-term memory.

Fluid intelligence, on the other hand, draws on the ability to understand relationships between various concepts, independent of any previous knowledge or skills, to solve new problems. The research shows that this part of intelligence can be improved through memory training.

“When it comes to improving intelligence, many researchers have thought it was not possible,” says Jaeggi. “Our findings clearly show this is not the case. Our brain is more plastic than we might think.”   (Read More…)

There is no pain

There’s only gain

When you can train

Your plastic brain.

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June 7th, 2008

Why our brains are so clumsy

Free thinking, indeed any kind of thinking, is dependent on the abilities of our brains.  Learning more about our brain can give us insight into the process and products of thinking.

In his new book, Kluge: The haphazard construction of the human mind, Gary Marcus aims to take the human species down a peg or two. We might like to think of ourselves as sleek and perfectly-adapted products of evolution, but Marcus instead describes the brain as a clumsy collection of spare parts. If evolution is so powerful, he asks, how did we end up so flawed?

Why do you think that the mind is a kluge?

There are two answers to that. The first is a general argument about evolution: that if you look at evolution it makes a lot of kluges. Evolution tends not to optimise things; it simply tinkers with what’s already there. So it tends to make things better but there’s no guarantee that it will make the best.

The second is an empirical argument. I look to see whether there is anything clumsy about the human mind, and I find lots of examples.

But we tend to think of evolution as something that produces the best possible solution to a problem.

And that’s just not true. Darwin didn’t actually say “survival of the fittest”; I think that was Huxley, but people take that as their crude approximation to evolution. They think that must mean that the fittest thing that could possibly be will survive, but really it means the fittest of the available options. Evolution can’t take a step back and ask what the best option would be; it just works with what it has. And that’s what leads to tinkering and ultimately the kluges.

You’ve said that we tend to think of evolution as a single slope but actually it’s more like a rocky terrain.

Absolutely. You can think of evolution as a process of hill climbing, but it’s a blind process of hill climbing. It can take small steps and it may get higher on the particular mountain peak that it’s on, but it might not realise that there’s a much higher peak off in the distance.

I think that happened with memory. Our memories work reasonably well, but there are much better solutions that evolution just never stumbled upon.

Couldn’t you argue that we are well-adapted for the environment that we evolved in, when we were living in small groups, looking for food? So there’s no problem with our minds, it’s just that the environment has changed.

There are some cases like that. For example, our desire for fats and sugars is mostly tuned to an environment where McDonalds wasn’t around and you couldn’t get these things so easily. But I think that with the memory system, evolution just made a mistake. Probably all creatures would be better served if their memory was better organised, but evolution just happened to go in this one direction. It’s very difficult for evolution to start from scratch and do something completely new.

What’s wrong with thinking of ourselves as perfectly designed, rational beings, when actually we’re not?

Economists make that mistake. They assume that humans are rational, but they aren’t necessarily. And I think that people almost always overestimate their own abilities. They overestimate the quality of their memory, and how careful they are at reasoning. That contributes to political polarisation, for example, where everyone is convinced that they know the truth and nobody else does. I don’t think that’s a very good thing for the species.

What can we do to make our minds work better?

In the long term we may be able to take control of evolution, to adopt new technologies or something like that. In the short term, what they say in Alcoholics Anonymous makes sense – recognition is the first step. We have to see what the limits are and try to work around them.

A good example is that we have this thing called confirmation bias, where we notice evidence that supports our own theories. You can counteract that by forcing yourself to systematically think about alternative hypotheses, and about the perspective that somebody else might take. We don’t do that naturally but we can train ourselves to do it.

Scientists are forced to do that to some extent. But everybody could do with a little bit more humility about their own intellectual powers, and realise that, if somebody disagrees with them, maybe they’re looking at the evidence in a different way; it’s not necessarily that they’re stupid and you’re smart. The more we can recognise that other people are working as best they can from their evidence, that could make us more sympathetic and perhaps we can get along better.

(Source)