Wednesday, February 19, 2003
We're beginning to be able to measure such intelligence not simply from the results of written or practical tests but from live imaging of actual brain activity. Egalitarian ideologues have long resisted the notion that there is such a thing as general intelligence and that it is at least partly hard-wired and inherited. But as science advances, and our understanding of working memory and intelligence deepens, the evidence for such intelligence could become irrefutable. Imagine at some distant date going into an exam room and getting hooked up to brain monitors. No need for grad students grading papers. No need for SAT results. Just a brain scan to check how smart you are. Fantasy now. But you can already see the implications of current research. Blank slaters, be afraid. Your time is running out.
Whoa, cowboy. The research doesn’t even support the fantasy, let alone the reality. What it did was find areas of the brain that are put into use during complex problem solving and reasoning - what’s called “fluid intelligence.”:
The Washington University study included 48 participants, all healthy, right-handed, native English speakers between the ages of 18 and 37, about half men and half women. Each participant was administered a standard test of fluid intelligence, known as Raven's Advanced Progressive Matrices. Each participant was then asked to perform the word and face "mental juggling" tasks while lying inside an fMRI scanner. Each task tested a kind of short-term memory known as "working memory."
The intelligence test was done to see if standard measures of intelligence corresponded with the ability to perform the challenging mental gymnastics of the study well. Here’s a description of the gymnastics:
To get a sense of how the task works, ask a friend to read the following words to you at a rate of about one word every 2.5 seconds: dog, cat, chair, table, cat, door, chair, dog.
For each word that you hear, make a mental note of whether it is the same word as you heard three words previously. That is, compare the fourth word you hear to the first, the fifth word to the second, and so on. (For the first three words, there is nothing to compare them to, so just remember them for later.)
The participants in the study had to do a similar task, except that it involved viewing a series of either unrelated words or unfamiliar faces on a computer screen, one word or face every few seconds. Participants had to press a button to indicate whether or not the word or face on the screen matched one shown exactly three previously.
The task is challenging, but the researchers included some especially tricky "lure" items that were even more difficult. These were words or faces that had been shown two, four, or five previously in the sequence, but not three previously.
For example, the second time the word "chair" appears in the list above is a lure. The lure items are easily confusable for an item seen three previously. The mere fact that the word or face was seen recently is salient and hard to ignore.
The people who did that task the best also happened to score higher on the intelligence test .Their scans also showed increased activity in certain regions of the brain while they were performing the task.
You could say the study maps concentration. It doesn’t demonstrate that brain scans can predict or record intelligence. The mind has to be engaged in a problem for the scan to see the difference between good problem solvers and poor problem solvers. It’s no different than a written test in that respect.
Nor does it prove that intelligence is innate and predetermined. One of the most amazing things about the mind is its ability to adapt and learn new things. Pathways in the brain are constantly changing and reshaping in response to our learning. That’s how stroke victims learn to talk and walk again, and how amputees learn to use their remaining arm as well as they once used the lost one. There’s nothing in the research to suggest that people can’t learn to recruit those regions of the brain that the good problem solvers used. Blank slaters still have hope.
posted by Sydney on 2/19/2003 08:57:00 PM 0 comments