Evidence-Based Neuroplasticity Effects from
IQ Mindware Training
Standard Dual N-Back Working Memory Training: What Is It?
Working memory (WM) brain training is the most effective type of brain training for general cognitive gains that has been developed. WM training programs is to expand working memory capacity.
The most widely studied brain training exercise targeting WM capacity is the dual n-back game. It is easy to master, but since it is adaptive can be played indefinitely while continuing to challenge and expand working memory capacity. The most well-known dual n-back task has been developed by Dr. Susanne Jaeggi and her colleagues back in 2008. We call this the ‘Standard’ dual n-back.
The scientifically well-established effectiveness of dual n-back training for increasing IQ and general cognitive ability gains is reviewed here and here. There has been some skepticism in the press over the years, but each month now new studies are showing long-term neuroplasticity effects from working memory training, with benefits for intelligence, attention, executive control and emotional self-regulation.
Critical Limitations of Standard Dual N-Back Training
Traditional dual n-back training has a number of critical limitations including the following:
- Lack of interference and executive control training. As we will see below, interference control training is a direct way of targeting executive functioning and intelligence networks.
- Poor motivation. N-back training is hard and traditional n-back apps on the market have a high drop out rate because of this.
- N-back compensatory strategies. The original Jaeggi dual n-back and its variants on the market do not counter a number of compensation strategies to maintain or improve n-back levels without associated gains in actual working memory capacity – such as chunking, attention blinking and playing the odds.
2G Dual N-Back
1. Interference Control Training
We now know that interference control is critical to high levels of fluid intelligence and working memory. Interference control is a kind of attention control – the ability to filter out distracting information or suppress irrelevant habits or responses, when faced with cognitive challenges. It is a kind of ‘executive control training.
Studies by Burgess, Gray, and fellow grad student Tod Braver (article 1, article 2) provide brain imaging evidence of a large overlap of Gf and WM span brain mechanisms when there is need for interference control on a task – but not otherwise.
What is ‘interference’ in the n-back? You may have experienced interference in the standard dual n-back when the sequence of stimuli repeats itself before the target is presented. This creates confusion where you have to ‘repeat yourself’ to keep the series of items in memory.
2. Speed/Variability: Executive Function Training
Electrical activity in the brain can be recorded using EEG electrodes on the scalp. Different types of brain waves (electrical oscillations) have been linked to sleep, navigation, cognition, attention, and can help diagnose a wide range of disorders including autism, schizophrenia and epilepsy.During standard dual n-back training, while our attention system keeps track of the updating letters and squares, sensory areas of the brain go into an electrical rhythm that matches the rhythm of the n-back letters and squares – for instance, every second. The n-back stimuli drive the cortex rhythmically (Lakatos et al., 2009).
The cortical brain rhythm helps process the stimuli, anticipating when the next sounds and squares will appear, and ‘binding’ the audio and visual information together in working memory.
How does this relate to real world cognition? Speech is rhythmic, our gestures are rhythmic, visual saccades (the moment to moment eye movements that we scan scenes or text with) are rhythmic. Our attention system works in these rhythms, resulting in periodic increases in excitability in anticipation of attended stimuli – making information processing more selective and efficient.
Standard dual n-back has a fixed 3-second stimulus rhythm. This slows down training, but also allows the attention system to become automatic, in synchrony with the 3 second rhythm.
The speed and variability of the stimuli in the IQ Mindware app’s n-back game can be systematically increased. This increase the speed and break the rhythm of the n-back stimuli, requires more focused attention and demands on executive functioning brain networks. This results in additional training gains.
3. N-Back Accuracy
In the original Jaeggi dual n-back algorithm, staying at the same n-back level without dropping down a level requires that you are 75% accurate. Going up an n-back level requires you are 85% accurate.
Because there is considerable room for error (such as missing targets) in these accuracy levels, it is possible to use game-specific strategies to improve your n-back score (see below). These strategies do not actually help you expand your brain’s working memory capacity, although they result in increasing n-back levels and the appearance of better working memory performance.
The accuracy level in our 2G n-back is set at a higher level. Higher accuracy levels, in combination with faster speed settings, can help prevent game-specific strategies that artificially increase your n-back levels.
Problematic Game Strategies With Standard N-Back
The following strategies are often used to increase n-back levels without actually increasing working memory capacity.
- Chunking. Sometimes during the standard dual n-back game, a letter or location may be repeated one two or even three times. When this happens it is easier perform on the n-back exercise because with only one ‘place holder’ there is less information to ‘encode’ to do the task. Or at other times, there may be a meaningful string of letters that forms a word or acronym, or the sequence of locations forms a known shape. When items can be grouped together like this, easing the burden on our memory system, this is called ‘chunking’. Chunking can also benefit from practice.
- Attention jumping. As you get more experienced with the standard dual n-back game it is possible to strategically direct your attention in ‘jumps’ to useful strings of letters or square locations in order to maintain or go up an n-back level. Using this strategy, you are not actually updating the items in your working memory continuously, but are ‘counting through’ a particular string of items and then refreshing it from the start again for the next string.
- Playing the odds. Another strategy that can be used in the standard dual n-back is ‘intelligent guessing’ when you are less precise with your location memory, for instance, but can make good guesses that the stimulus was to the left, or to the right for instance. This gives you better ‘odds’ at reach the required level of accuracy to maintain or go up an n-back level.
Using any of these strategies is counter-productive for working memory training. And here’s why. These strategies are actually ways of getting around (i.e. compensating for) limitations of working memory capacity to increase your n-back performance. But getting practice with these strategies does not actually help increase working memory capacity itself.
IQ Mindware accuracy and speed settings can help prevent the use of these strategies.