Editing Working memory (section)

== Training ==
{{Further|Working memory training|Neurobiological effects of physical exercise#Cognitive control and memory}}

Some studies in the effects of training on working memory, including the first by [[Torkel Klingberg]], suggest that working memory in those with [[ADHD]] can improve by training.<ref>{{cite journal | vauthors = Klingberg T, Forssberg H, Westerberg H | title = Training of working memory in children with ADHD | journal = Journal of Clinical and Experimental Neuropsychology | volume = 24 | issue = 6 | pages = 781–791 | date = September 2002 | pmid = 12424652 | doi = 10.1076/jcen.24.6.781.8395 | s2cid = 146570079 }}</ref> This study found that a period of [[working memory training]] increases a range of cognitive abilities and increases IQ test scores. Another study by the same group<ref>{{cite journal | vauthors = Olesen PJ, Westerberg H, Klingberg T | title = Increased prefrontal and parietal activity after training of working memory | journal = Nature Neuroscience | volume = 7 | issue = 1 | pages = 75–79 | date = January 2004 | pmid = 14699419 | doi = 10.1038/nn1165 | s2cid = 6362120 }}</ref> has shown that, after training, measured brain activity related to working memory increased in the prefrontal cortex, an area that many researchers have associated with working memory functions. One study has shown that working memory training increases the density of [[prefrontal cortex|prefrontal]] and [[parietal cortex|parietal]] [[dopamine receptor]]s (specifically, [[DRD1]]) in test subjects.<ref>{{cite journal | vauthors = McNab F, Varrone A, Farde L, Jucaite A, Bystritsky P, Forssberg H, Klingberg T | title = Changes in cortical dopamine D1 receptor binding associated with cognitive training | journal = Science | volume = 323 | issue = 5915 | pages = 800–802 | date = February 2009 | pmid = 19197069 | doi = 10.1126/science.1166102 | bibcode = 2009Sci...323..800M | s2cid = 206516408 }}</ref> However, subsequent experiments with the same training program have shown mixed results, with some successfully replicating, and others failing to replicate the beneficial effects of training on cognitive performance.<ref name=":3">{{cite journal | vauthors = Katz B, Shah P, Meyer DE | title = How to play 20 questions with nature and lose: Reflections on 100 years of brain-training research | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 115 | issue = 40 | pages = 9897–9904 | date = October 2018 | pmid = 30275315 | pmc = 6176639 | doi = 10.1073/pnas.1617102114 | doi-access = free | bibcode = 2018PNAS..115.9897K }}</ref>

In another influential study, training with a working memory task (the dual [[n-back]] task) improved performance on a fluid [[intelligence test]] in healthy young adults.<ref>{{cite journal | vauthors = Jaeggi SM, Buschkuehl M, Jonides J, Perrig WJ | title = Improving fluid intelligence with training on working memory | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 105 | issue = 19 | pages = 6829–6833 | date = May 2008 | pmid = 18443283 | pmc = 2383929 | doi = 10.1073/pnas.0801268105 | doi-access = free | bibcode = 2008PNAS..105.6829J }}</ref> The improvement of fluid intelligence by training with the n-back task was replicated in 2010,<ref name="JaeggiStuder-Luethi2010">{{cite journal| vauthors = Jaeggi SM, Studer-Luethi B, Buschkuehl M, Su YF, Jonides J, Perrig WJ |title=The relationship between n-back performance and matrix reasoning – implications for training and transfer|journal=Intelligence|volume=38|issue=6|year=2010|pages=625–635|issn=0160-2896|doi=10.1016/j.intell.2010.09.001}}</ref> but two studies published in 2012 failed to reproduce the effect.<ref name="RedickShipstead2013">{{cite journal | vauthors = Redick TS, Shipstead Z, Harrison TL, Hicks KL, Fried DE, Hambrick DZ, Kane MJ, Engle RW | display-authors = 6 | title = No evidence of intelligence improvement after working memory training: a randomized, placebo-controlled study | journal = Journal of Experimental Psychology. General | volume = 142 | issue = 2 | pages = 359–379 | date = May 2013 | pmid = 22708717 | doi = 10.1037/a0029082 | s2cid = 15117431 }}</ref><ref name="ChooiThompson2012">{{cite journal| vauthors = Chooi WT, Thompson LA | title=Working memory training does not improve intelligence in healthy young adults| journal=Intelligence| volume=40|issue=6| year=2012| pages=531–542| issn=0160-2896| doi=10.1016/j.intell.2012.07.004}}</ref> The combined evidence from about 30 experimental studies on the effectiveness of working-memory training has been evaluated by several meta-analyses.<ref>{{cite journal |last1=Au |first1=Jacky |last2=Sheehan |first2=Ellen |last3=Tsai |first3=Nancy |last4=Duncan |first4=Greg J. |last5=Buschkuehl |first5=Martin |last6=Jaeggi |first6=Susanne M. |title=Improving fluid intelligence with training on working memory: a meta-analysis |journal=Psychonomic Bulletin & Review |date=April 2015 |volume=22 |issue=2 |pages=366–377 |doi=10.3758/s13423-014-0699-x |pmid=25102926 |url=https://escholarship.org/uc/item/1mj701dj }}</ref><ref>{{cite journal | vauthors = Melby-Lervåg M, Redick TS, Hulme C | title = Working Memory Training Does Not Improve Performance on Measures of Intelligence or Other Measures of "Far Transfer": Evidence From a Meta-Analytic Review | journal = Perspectives on Psychological Science | volume = 11 | issue = 4 | pages = 512–534 | date = July 2016 | pmid = 27474138 | pmc = 4968033 | doi = 10.1177/1745691616635612 }}</ref> The authors of these meta-analyses disagree in their conclusions as to whether or not working-memory training improves intelligence. Yet these meta-analyses agree that, the more distant the outcome measure, the weaker is the causal link – training working memory almost always yields increases in working memory, often in attention, and sometimes in academic performance, but it is still an outstanding question what exact circumstances differs between cases of successful and unsuccessful transfer of effects.<ref name=":4">{{Cite report | vauthors = Berger EM, Fehr E, Hermes H, Schunk D, Winkel K |date=2020 |title=The Impact of Working Memory Training on Children's Cognitive and Noncognitive Skills |doi=10.2139/ssrn.3622985|s2cid=221652470 |hdl=10419/222352 |hdl-access=free }}</ref><ref name=":3" />