There are some strong evidence that N-back training improve fluid intelligence (Au et al., 2014). However not every user experiences such positive effect. In some cases N-back training doesn't work. Why?
About century ago Charles Spearman discovered that measurements of different cognitive abilities are correlated. It means that people who for example are good at mathematics, are usually also good at languages, science and other subjects. That observation led Spearman for introduction of the idea called general intelligence, in short: g.
I have just read a blog post, written by Russian emigrant, who was offered to pass an IQ test to join the Mensa community.
The main point of the post is there are often tasks in IQ test having multiple correct solutions. IQ test authors often instruct in these cases to choose the simplest one. And this is the main problem.
It's been a long time since I made a record in the blog about the mental math experiment.
At first I had sickness that kicked my brains out of sharp state for about a decade. Then I had a lot of work on my regular job and on BrainScale.net site too. So I interrupted my training until better times.
And now I feel the time has come to continue training.
I noticed some progress in the mental math.
Today is the second day in a row when I have a rate more than 50% in 3x3 multiplication. Yesterday it was 60% today is 70%.
Today is the first day I reached level 3.3.
I usually start doing mental math exercise from level 1.1 and increasing level if success rate was 80% or higher. During previous days I was able to reach level 3.2.
Creating the mental math exercise I needed a way to measure the progress user achieved. Some kind of mental math index that can be tracked over the time and can be compared to the other users index.
It should have taken into account the number of digits in numbers being operated. It should also have taken into account different complexity of the multiplication and addition operations.
Day 10.
I continue doing the position-numeric N-Back task. There wasn't much progress these days. I'm still on level 5.
There were some tough days on my main job, so I didn't have much time to work on mental math. I just added some basic statistics.
Today is the 5-th day I started experiment with the N-Back task (numeric) and mental math calculations. For Numeric N-Back I use Dual N-Back task with position and numeric signals.
First 5 days I only used the N-Back task.
Recently I started an experiment on the mental math training. But before the experiment details I'd like to have a few words on why I decided to do the mental math exercises at all.
I always liked the ability to operate big numbers in mind. Multiplication of two two-digit numbers mentally was possible but took a lot of time, multiplication of two three-digit numbers seemed as something unreachable. When I tried to do it I met some insuperable barriers like forgetting intermediate results in the process of calculation or some mental distractions that led me to loosing focus on the task.
At the same time I felt I could do it after some trainings that will allow me to expand my working memory limits and stay more focused. By that time I have already been doing N-Back task for a while and reached the Dual 7-Back level. So, I decided to add mental math exercise to the site. I also decided to make an experiment on how long will it take me to be able to multiply two three-digit numbers in mind.