We’ve discovered through a series of experiments now that were able to improve fluid intelligence which is the ability to think creatively, productively not just are recalling things that come from memory by training what most people call short-term memory what psychologists often called working memory. This is a remarkable result because it’s often thought that fluid intelligence is something that you’re born with the training should last 15 to 20 minutes a day in order to be effective. There are websites available where you can find the n-back task at no cost to you there are also commercially available products that you can buy that will give you training not only in the n-back task but other kinds of cognitive training tasks as well and you can track your own performance to see how much better you get over time.
Our discovery is that for weeks or so of training will produce a noticeable difference in fluid intelligence were able to show this not only in young adults which is what our first experiment was about but also in young children. We’ve also shown that the longer you train short-term memory the more improvement you get in IQ. We chose the n-back task for specific reasons what you have to do is to match an item that currently appears with an item that was n items back in the sequence. The interesting feature of this task is that we can make it as difficult as we want by increasing n. So if i make it a two-back task you now have to match the item that I present you with the item that was presented to items ago and I myself can get up to five back fairly successfully and we’ve had subjects in the laboratory who’ve done as much as nine to ten to eleven back successfully.
In fact, we’ve had young children who’ve done nine back in when we tested this experiment in young children as well. One of the things that interests us is not only that we have this effect and that we can improve IQ but we’re interested in why it works and in order to delve into that question we’ve looked at the brain mechanisms that change as a function of training are actually two possible accounts here. One is that as you become more proficient at the task you you need less neural activity in order to accomplish that proficiency because you’ve developed a more efficient way of processing the information in the task.
The other possibility is that your brain becomes more prepared to engage in the task as you get more practiced. When we first started working with the dual n-back task one of the thoughts that we had was that the effectiveness of the task hinged on the fact that you had to do two tasks at the same time, a visual match and an auditory match. In a later experiment we actually compare the dual n-back task against the single n-back task and discovered that the simply single and back task was just as effective as the dual n-back task. So this is exciting it means that we can bring our result to a wider swath of the population than we could before.