Assessment | Biopsychology | Comparative | Cognitive | Developmental | Language | Individual differences | Personality | Philosophy | Social |
Methods | Statistics | Clinical | Educational | Industrial | Professional items | World psychology |

Cognitive Psychology: Attention · Decision making · Learning · Judgement · Memory · Motivation · Perception · Reasoning · Thinking  - Cognitive processes Cognition - Outline Index

File:N-back Suite for iPhone.png

The n-back task is a Continuous Performance Task that is commonly used in neuroimaging to stimulate brain activity in test subjects. It was introduced by Kirchner in 1958.[1]

The taskEdit

The subject is presented with a sequence of stimuli, and the task consists of indicating when the current stimulus matches the one from n steps earlier in the sequence. The load factor n can be adjusted to make the task more or less difficult.

For example, an auditory three-back test could consist of the experimenter reading the following list of letters to the test subject:


The subject is supposed to indicate when the letters marked in bold are read, because those correspond to the letters that were read three steps earlier.

Dual n-backEdit

The dual-task n-back task was proposed by Susanne Jaeggi et al. in 2003.[2] In this variation, two independent sequences are presented simultaneously, typically using different types of stimuli, such as one auditory and one visual.

In a 2008 research paper Jaeggi et al. claim that practicing a dual n-back task can increase fluid intelligence (Gf), as measured in several different standard tests.[3]. The paper's methodology has been criticized by David Moody.[4] He draws attention to the fact that different tests were used to evaluate the control and test groups. Due to the way in which the tests were administered, he also questions whether they were valid tests of fluid intelligence. For example, the progressive nature of the tests was undermined by severe time-restriction (10 minutes were allowed to complete a normally 45-minute test). In a subsequent study, Jaeggi et al addressed Moody's timing restriction criticism by noting that "that scores in timed versions of the APM are nicely predictive of scores in untimed versions (Frearson & Eysenck, 1986; Hamel & Schmittmann, 2006; Heron & Chown, 1967; Salthouse, 1993; Unsworth & Engle, 2005)". [5]

The study was replicated in 2010 with results indicating that practising single n-back may be almost equal to dual n-back in increasing the score on tests measuring Gf.[6]

There is a growing amount of evidence that cognitive training can have significant effects on the brain. In 2009, it was reported in Science that '14 hours of training over 5 weeks' on a variety of working memory related tasks (not including the n-back) led to measurable density changes for cortical dopamine neuroreceptors.[7]

Software implementationsEdit

The dual n-back task can be played online,[8][9] on most Java-enabled mobile phones (including Android and BlackBerry smartphones),[10] the iPhone,[11][12] and Android.[13][14] There is also a free, open-source application available for Mac OS, Linux, and Windows called Brain Workshop.[15] The University of Bern sells the Jaeggi-Buschkuehl implementation in its Brain Twister suite.[16]

The suite of working memory training tasks used in the study on dopamine receptor levels is available from Pearson Education.[17]


  1. Kirchner, W. K. (1958), Age differences in short-term retention of rapidly changing information. Journal of Experimental Psychology, 55(4), 352-358
  2. Jaeggi, S. M., Seewer, R., Nirkko, A. C., Eckstein, D., Schroth, G., Groner, R., et al., (2003). Does excessive memory load attenuate activation in the prefrontal cortex? Load-dependent processing in single and dual tasks: functional magnetic resonance imaging study, Neuroimage 19(2) 210-225.
  3. Jaeggi, S. M., Buschkuehl, M., Jonides, J., Perrig, W. J. (2008), Improving fluid intelligence with training on working memory, Proceedings of the National Academy of Sciences, vol. 105 no. 19
  4. Moody, D. E. (2009), Can intelligence be increased by training on a task of working memory? Intelligence, Volume 37, Issue 4, July–August 2009, Pages 327-328, DOI: 10.1016/j.intell.2009.04.005
  5. (2010). The relationship between n-back performance and matrix reasoning -- implications for training and transfer. Intelligence 38 (6): 625–635.
  6. (2010). The relationship between n-back performance and matrix reasoning -- implications for training and transfer. Intelligence 38 (6): 625–635.
  7. "Changes in Cortical Dopamine D1 Receptor Binding Associated with Cognitive Training", Fiona McNab, Andrea Varrone, Lars Farde, Aurelija Jucaite, Paulina Bystritsky, Hans Forssberg, Torkel Klingberg. Science 6 February 2009: Vol. 323. no. 5915, pp. 800 - 802
  8., website
  9. CognitiveFun, website
  10. EFRAC IQ - Dual N-Back for Android, BlackBerry and Nokia smartphones, website
  11. IQ boost
  12. N-back Suite, website
  13. Brain N-Back for Android, Android Market
  14. Dual N Back for Android (source code only), n-back (free application, no source code), NBack
  15. Brain Workshop at sourceforge, free dual n-back game; see also a Haskell implementation, hback
  16. Brain Twister at University of Bern
  17. Cogmed Working Memory Training from Pearson Education
This page uses Creative Commons Licensed content from Wikipedia (view authors).

Ad blocker interference detected!

Wikia is a free-to-use site that makes money from advertising. We have a modified experience for viewers using ad blockers

Wikia is not accessible if you’ve made further modifications. Remove the custom ad blocker rule(s) and the page will load as expected.