Task switching training effects are mediated by working-memory management Maayan Pereg ⁎, Nitzan Shahar, Nachshon Meiran Department of Psychology and Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel article info abstract Article history: Received 17 January 2013 Received in revised form 26 May 2013 Accepted 11 June 2013 Available online 16 July 2013 Task switching is an important executive function, and finding ways to improve it has become a major goal of contemporary scientists. Karbach and Kray (2009) found that training in the Alternating-Runs Task-Switching (AR-TS) paradigm (in which the task changed every second trial) reduced the costs of switching in untrained tasks, as well as led to far transfer to interference control ability and fluid intelligence. However, AR-TS is known to involve working memory updating (WMU). Therefore, we hypothesized that AR-TS training involves WMU and not task-switching proper. Participants were trained using Karbach and Kray's protocol. Results indicate a highly specific transfer pattern in which participants showed near transfer to switching cost in the AR-TS paradigm, but did not significantly improve in another version of the task switching paradigm in which the tasks were randomly ordered or a version in which the task changed every 3rd trial. The results suggest that what has been trained is not a broad task-switching ability but rather a specific skill related to the unique WMU requirements of the training paradigm. © 2013 Elsevier Inc. All rights reserved. Keywords: Cognitive training Executive functions Working memory Task switching 1. Introduction Executive functions are cognitive abilities enabling goal directed behavior. As such, they have broad relevance to issues such as general intelligence (Friedman et al., 2006), psychopa- thology (e.g., Kashdan & Rottenberg, 2010; Morgan & Lilienfeld, 2000; Pennington & Ozonoff, 1996), psychological develop- ment (e.g., Garon, Bryson, & Smith, 2008; Zelazo, Carlson, & Kesek, 2008), and school performance (e.g., Diamond, Barnett, Thomas, & Munro, 2007). Knowing how to improve executive functions is therefore likely to have an enormous impact on a wide array of psychological domains. There is no clear consensus on the taxonomy of executive functions, and whether they represent a single ability or a range of abilities (e.g., Baddeley, 1986, vs. Lehto, 1996). Nonetheless, many studies adopt Miyake et al.'s (2000) taxonomy, which was based on individual differences within the normal range. According to Miyake et al., there are three executive functions including updating and monitoring of working memory repre- sentations (WMU), inhibition of prepotent responses (inhibi- tion) and shifting between tasks or mental sets (task switching). Several studies in the past few years demonstrated that training in a cognitive task tapping an executive function could result in far transfer to general intelligence (e.g., Jaeggi, Buschkuehl, Jonides, & Perrig, 2008; Klingberg et al., 2005; Schmiedek, Lövdén, & Lindenberger, 2010). By “far transfer” we refer to improvements seen in a structurally different task than the training task (that involves different content and task requirements, yet tapping similar critical psychological pro- cesses), as opposed to near transfer effects which relate to specific attributes of the training task. The transfer is allegedly based on the fact that the training program and the transfer tasks have a common element through which the training occurs. Showing far transfer of executive function training is especially interesting in light of findings suggesting that individual differences in executive functions are mainly genetic in origin (Friedman et al., 2008). In line with the genetic findings, there have been some recent reports showing failures Intelligence 41 (2013) 467–478 ⁎ Corresponding author at: Department of Psychology, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel. E-mail address: maayanru@post.bgu.ac.il (M. Pereg). 0160-2896/$ – see front matter © 2013 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.intell.2013.06.009 Contents lists available at ScienceDirect Intelligence