Working Memory and Fluid Intelligence

What is Working Memory?

Working memory is an idea developed by cognitive scientists to describe how people are able to hold information relevant to a particular task in their mind, while having to simultaneously process information relating to other tasks and contend with additional distracting information.

Many fundamental cognitive abilities including; reading, reasoning, and problem solving all require input from working memory in order to function.

The relevant information is held in an accessible state, where you can continue to use and manipulate it. However because it must be continually held in this state it also has a limited capacity. Put another way; there is only so much information your mind can hold onto at one time, this limit is your Working Memory Capacity.

Working Memory and Fluid Intelligence

Throughout the 1990s many cognitive scientists believed that Working Memory Capacity and General Intelligence (g) were one and the same thing. Studies such as ‘Reasoning ability is (little more than) working-memory’, published in the journal ‘Intelligence’ by Kyllonen and Christal showed correlations between Working Memory and reasoning ability of between 80% and 90%. These and other similar results led most working in the field to conclude that even if working memory was not all there was to intelligence it was certainly the single most important factor.

What is Fluid Intelligence?

Along with Crystalized Intelligence, Fluid Intelligence is one of the two key factors which contribute to General Intelligence according to the Cattell & Spearman model of Intelligence. You can read more about the different theories of intelligence in the post What is Intelligence?

Most of the research that demonstrates the link between Working Memory and Intelligence has focused on testing reasoning abilities rather than acquired knowledge. Therefore it is actually a link between Working Memory and Fluid Intelligence that was being shown.

This aligns well with our common sense, when we are trying to measure intelligence we aren’t interested in pre-prepared strategies or relevant things we may just happen to know, but rather with how we cope with novel, unfamiliar problems.

More recent studies and analysis such as that done by Kane, Hambrick and Conway; ‘Working memory capacity and fluid intelligence are strongly related constructs’, have shown the original estimates of 80-90% correlations to be slightly over-optimistic.

When a battery of both simple and complex span working memory capacity tasks are included, Working Memory Capacity appears to accounts for around half of the variation in different individuals Fluid Intelligence.

Principles of Increasing Intelligence

Many exercises and techniques have been demonstrated to improve various aspects of cognitive performance, and some specific techniques which show transferable increases in intelligence have also been found. However most brain training exercises and games do not give any benefit beyond an improved ability to play that particular game.

If some exercises are successful at increasing intelligence while the majority are not, it is reasonable to conclude that simply engaging in any mental exercise isn’t sufficient, but rather there must be certain features or properties of these successful exercises which enable them to be effective.

What are the basic principles that form the foundations of successful exercises and techniques designed to increase intelligence? Can we extract out these principles in order to use them to design our own techniques, or directly integrate them into our lives? 

First Principle of Increasing Intelligence – Novelty

Our brains naturally seek novelty. The most rewarding experiences are those which take us out of comfort zone, providing new sensations, introducing us to new ideas and causing us to have new thoughts. This novelty also appears to be key for increasing intelligence.

When confronted with something new, your brain looks for ways to process the information more efficiently. It does this by seeking out patterns in the new activity i.e. trying to learn and understand what it is all about. All the while it is doing this the relevant regions of the brain show more activity and use up more energy. 

But the brain doesn’t like to work in this way, so it makes new, more direct neural connections allowing it to achieve the same results with less activity and using up less energy.

These new connections build on each other, increasing your overall neural activity. The more new activities you engage in, the more your synaptic network grows, creating more and more connections. In turn these connections allow for more associations in your mind, improving your ability to spot patterns, and to see where you can take ideas from one situation and apply them to another. This is a fundamental aspect of intelligent problem solving.

Second Principle of Increasing Intelligence – Difficulty

Our brains are naturally lazy. When you consider all the activities it has to be constantly engaged with in order to keep us functioning this might not seem obvious, but our brain will always take the easiest way out to get its job done. Since it is much easier to use existing neural pathways rather make new connections it will always do this wherever possible

To increase your intelligence, you need to force your brain to make these new connections by constantly challenging your brain. When something is difficult it means there is no ‘well trodden path’ in your neural network.  In order to work out a strategy or come up with a solution for a problem you find difficult, your brain will need to use a lot of energy to send signals round long winding neural paths to engage and pull information from separate brain regions.

Because it is lazy, your brain will soon realize it is a much easier option just to create new neural pathways that act as a shortcut rather than always having to go the long way round.

Creating more efficient pathways means you will be able to more easily solve complex problems. Things which used to be difficult, won’t seem so hard anymore. In order to keep creating these new more efficient neural pathways you will need to keep increasing the difficulty of the challenges you provide your brain. The idea is to aim for that state of slight discomfort you feel when you are just out of your depth.

Bringing the principles together

So what does this tell us about how to get the most from your brain training, well really it’s all about the individual. An exercise which might give one person’s brain a good workout, won’t do anything for someone else. So if you find Sudoku puzzles really difficult then they are a good brain training exercise, but  if you have got to the point where you can complete most puzzles in 5 minutes flat, they are no longer giving you any real cognitive benefit.

So the takeaway advice for using these principles to increase your intelligence; Look for new novel mental challenges which take you out of your comfort zone, but the soon as you feel comfortable its time to move on to a new challenge.