Does working memory training have to be adaptive?

Abstract

This study tested the common assumption that, to be most effective, working memory (WM) training should be adaptive (i.e., task difficulty is adjusted to individual performance). Indirect evidence for this assumption stems from studies comparing adaptive training to a condition in which tasks are practiced on the easiest level of difficulty only [cf. Klingberg (Trends Cogn Sci 14:317-324, 2010)], thereby, however, confounding adaptivity and exposure to varying task difficulty. For a more direct test of this hypothesis, we randomly assigned 130 young adults to one of the three WM training procedures (adaptive, randomized, or self-selected change in training task difficulty) or to an active control group. Despite large performance increases in the trained WM tasks, we observed neither transfer to untrained structurally dissimilar WM tasks nor far transfer to reasoning. Surprisingly, neither training nor transfer effects were modulated by training procedure, indicating that exposure to varying levels of task difficulty is sufficient for inducing training gains. Can fluid cognitive abilities such as working memory (WM) and reasoning be improved through computer-based WM training? This is a highly controversial question, with prior empirical studies (for reviews, see Morrison & Chein, 2011;von Bastian & Oberauer, 2014) and meta-analyses (Au et al., in press;Karbach & Verhaeghen, 2014;Lampit, Hallock, & Valenzuela, 2014;Melby-Lervåg & Hulme, 2013) providing contradictory findings. Although multiple previous studies revealed promising effects (e.g., Jaeggi, Buschkuehl, Jonides, & Perrig, 2008;Jaeggi, Buschkuehl, Shah, & Jonides, 2014;Jaeggi et al., 2010; Klingberg et al., 2005;Schweizer, Hampshire, & Dalgleish, 2011;Stepankova et al., 2014;, a growing number of other WM training interventions failed to induce such broad transfer (e.g., Chein & Morrison, 2010;Chooi & Thompson, 2012;Colom et al., 2013;Harrison et al., 2013;Redick et al., 2013;Salminen, Strobach, & Schubert, 2012; Sprenger et al., 2013;Thompson et al., 2013;von Bastian, Langer, Jäncke, & Oberauer, 2013). The factors contributing to the success of WM training interventions in terms of improving WM and reasoning are still unclear (see von Bastian & Oberauer, 2014), and large variations (and, in some occasions, serious flaws) in the methodologies and training regimens used complicate comparisons across studies (cf. Shipstead, Redick, & Engle, 2012), and thus the identification of such factors. Therefore, before we can conclude whether and under which circumstances WM training can induce transfer, carefully controlled, systematic investigations of factors potentially contributing to training effectiveness are needed.In theory, cognitive plasticity occurs if there is a "prolonged mismatch between functional organismic supplies and environmental demands" (Lövden, Bäckman, Lindenberger, Schaefer, & Schmiedek, 2010, p. 659). According to Lövden and colleagues (2010), this mismatch occurs if the environmental demands exceed the routine demands the cognitiv...

Working memory training in healthy young adults: Support for the null from a randomized comparison to active and passive control groups

“…Looking to the literature, these results are consistent with a large and growing body of empirical work in support of the null for WM training [see 26, 36–45]. However, due to the largely divided or ‘reliably ambiguous’ [60] nature of the current WM training literature, these results are also inconsistent with a large and growing opposing body of empirical work that has demonstrated evidence for both near- and far-transfer effects resulting from WM training in healthy adults [28–35, 43].…”

“…facilitation of WM capacity by WM training) of WM abilities, examples of far-transfer (i.e. facilitation of untrained abilities by WM training) to Gf have been more elusive, as well as generally weaker and less durable when they have been found (see [26, 36–45]). Rather, to this point there exists a striking lack of consensus in the literature about whether or not training on WM tasks generalizes to Gf , and secondly, the specific methodology by which these claims ought to be tested.…”

Reevaluating the effectiveness of n-back training on transfer through the Bayesian lens: Support for the null

“…While we argue that the meta-analysis of n-back training does not support the contention that Gf improves with short-term cognitive training, this does not mean that n-back training does not lead to other forms of transfer: Training on n-back is likely to lead to improvements on other tasks that are similar in design and structure to the n-back task, as demonstrated by Lilienthal, Tamez, Shelton, Myerson, and Hale (2013) and von Bastian and Eschen (2015). However, such transfer effects are neither surprising nor of much practical interest, and neither of these studies found evidence for far transfer.…”

“…2 Unfortunately, deviation from the double-blind procedure is the norm within the cognitive training literature: We know of only a small number of studies that attempted to use a double blind placebo-control procedure (Sprenger et al, 2013, Study 2;von Bastian & Eschen, 2015). Most studies either use a no-contact control condition (no placebo control and often referred to as a passive control), or a single-blind placebo control (often referred to as an active control) in which the experimenter interacting with the subjects knows group assignment, but the participant is blinded (as much as possible) to whether he or she was assigned to the true intervention or a sham intervention.…”

Frontoparietal neurostimulation modulates working memory training benefits and oscillatory synchronization

“…While the current task was not adaptive by design, some research groups argue that training must be adaptive to promote transfer and improvement in fluid intelligence (Brehmer, Westerberg, & Backman, 2012; Jaeggi, Buschkuehl, Jonides, & Perrig, 2008; Jaeggi, Buschkuehl, Jonides, & Shah, 2011; Karbach, Strobach, & Schubert, 2015; further reviewed in: Au, et al, 2015; Klingberg, 2010). However, other researchers have challenged the reliability and necessity of adaptive training paradigms (reviewed in: von Bastian & Eschen, 2016). Importantly, previous research indicates that WM training paired with tDCS improves performance in both adaptive (Au, et al, 2016; Richmond, et al, 2014) and non-adaptive WM training paradigms (Jones, Stephens, et al, 2015; Park, et al, 2014; (Stephens & Berryhill, 2016).…”