Interference Control Brain Training

Interference in HighIQPro’s 2G Dual N-Back Game


Based on brain imaging research over the past 3 years we now know that interference control is the link between n-back training and IQ. Interference control is a kind of attentional control – the ability to filter out distracting information or suppress irrelevant habits or responses, when faced with cognitive challenges.

What is ‘interference’ in the dual 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..

The level of interference in 2G n-back training can be systematically increased. This is not possible in standard dual n-back training which does not incorporate interference control training.

Interference Control Science: The Link Between Working Memory and IQ

HighIQPro is a working memory training app. How is working memory and IQ (general intelligence) related? How does working memory training transfer to gains in intelligence?

The link is via fluid intelligence. Our fluid intelligence (Gf) is our reasoning and novel problem solving ability – the key elements of how smart we are.  Gf is the best predictor of performance on diverse IQ tasks, so much so that Gf and general intelligence (G) have been considered to be the same ability.

So what is shared between fluid intelligence and working memory? The answer – we now know –  is interference control – the ability to filter out distracting information while engaging in some cognitive task, using your attentional focus.

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. They found that brain regions common to fluid intelligence and working memory became more active when there was more need to filter out distractions (‘lures’). The brain areas underlying both interference control, working memory capacity and fluid intelligence were the lateral prefrontal cortex (lPFC) and parietal cortex, shown in the fMRI images below which show activation in both the left and right hemispheres of the brain.


interference control brain regions


Burgess, G. C., Gray, J. R., Conway, A. R. A., & Braver, T. S. (2011). Neural mechanisms of interference control underlie the relationship between fluid intelligence and working memory span. Journal of Experimental Psychology: General140(4), 674–692.


Explanation for Why Evidence is Mixed for IQ Gains from Standard Dual N-Back Training

Some studies such as this one and this one provide evidence for IQ gains from n-back training, while others such as this one and this one do not. Why the inconsistency?

An explanation is that dual n-back exercises do no incorporate interference control Simply by accident, some n-back algorithms may have more interference than others – accounting for the inconsistent results.  HighIQPro v.4 is the only app that provides users with control over interference level.



Burgess, G. C., Gray, J. R., Conway, A. R. A., & Braver, T. S. (2011). Neural mechanisms of interference control underlie the relationship between fluid intelligence and working memory span. Journal of Experimental Psychology: General, 140(4), 674–692. doi:10.1037/a0024695[space]
Carpenter, P.A., Just, M.A.  & Shell, P. (1990) What one intelligence test measures: A theoretical account of the processing in the Raven Progressive Matrices Test. Psychol Rev. 97:404 – 431.[space]
Carroll, J. (1993). Human Cognitive Abilities: A Survey of Factor–Analytic Studies. Cambridge Univ. Press, Cambridge, UK.[space]
Gray, J. R. (2004). Neurobiology of intelligence: science and ethics. Nat Rev Neurosci, 5(6), 471–482.[space]
Gray, J. R., Chabris, C. F., & Braver, T. S. (2003). Neural mechanisms of general fluid intelligence. Nat Neurosci, 6(3), 316–322. doi:10.1038/nn1014.[space]
Tsuchida, Y., Katayama, J., & Murohashi, H. (2012). Working memory capacity affects the interference control of distractors at auditory gating. Neuroscience Letters, 516(1), 62–66. doi:10.1016/j.neulet.2012.03.057