Working memory training does not improve intelligence in healthy young adults

Transfer to sequencing and/or complex WM tasks has been reported by some N-back training studies but not others.

“Transfer to sequencing and/or complex WM tasks has been reported by some57–63, but not other N-back training studies58,64–70.”

Other researchers have also been unable to demonstrate transfer to reasoning and fluid ability tasks from working-memory training.

“In this our results mirror those of other researchers who have also been unable to demonstrate transfer to reasoning and fluid ability tasks from working-memory training (Chooi & Thompson, 2012;Colom et al., 2013;Harrison et al., 2013;Heinzel, et al., 2014;Redick et al., 2013;Schwarb, Nail, & Schumacher, 2015;Sprenger, et al., 2013;Thompson, et al., 2013;von Bastian & Eschen, 2015).”

The typical size of trained groups is small (~15 per group).

“Since the typical size of trained groups is also small (~15 per group; Chooi & Thompson, 2012; De Simoni & von Bastian, 2018; Gibson et al., 2012; Redick et al., 2013; Thompson et al., 2013)”

The evidence to date largely indicates little transfer across n-back and complex span paradigms.

“The evidence to date largely indicates little transfer across n-back and complex span paradigms.”

The finding of no evidence for cross-paradigm transfer is consistent with many previous studies using less systematic designs.

“This is consistent with many previous studies in which less systematic designs have been used to map transfer (Jaeggi et al., 2008, 2010; Li et al., 2008; Chooi and Thompson, 2012; Lilienthal et al., 2013; Oelhafen et al., 2013; Redick et al., 2013; Sprenger et al., 2013; von Bastian et al., 2013; Bürki et al., 2014; Minear et al., 2016; Schwarb et al., 2016).”

In several studies comparing dual n-back training to active or no contact control groups, training related gains were not identified in any group relative to another for any outcome.

“in several studies comparing dual n-back working memory training to either active or no contact control groups, training related gains were not identified in any one group relative to another for any outcome [24–26].”

Our findings support previous work which fails to replicate near and far transfer benefits of dual n-back working memory training when directly compared to an active control condition.

“Our findings support previous work which fails to replicate near and far transfer benefits of dual n-back working memory training when directly compared to an active control condition (see [24–26]).”