Conditions of Effectiveness and Near and Far Transfer Effects of Executive Function’s Interventions: Systematic Review

Executive functions (EFs; also called executive control or cognitive control) refer to a family of top–down mental processes needed when you have to concentrate and pay attention. different types of interventions have focused on trying to improve executive functions (EFs). However, the generalizability of these training to complex everyday functions namely "near and far transfer effect" of cognitive training is one of the most challenging topics in the field of cognitive science, disability and rehabilitation. Given the role of executive dysfunction in cognitive and educational disorders on the one hand and inconsistency results in the near and far transfer effect of executive function’s interventions, on the other hand, caused to be necessary attention to the variables that affect the effectiveness and generality of these interventions. In order to solve this problem, a closer look at interventional studies can illustrate the role of the characteristics and variables that affect the success or failure of the transfer of cognitive program effects. The purpose of the present study was to introduce the variables and conditions affecting the near and far transfer effects of executive function’s interventions.

The present study was a systematic review and descriptive study. The materials reviewed were all electronically published studies relevant to the subject, published in scientific databases including; Sage pub, PubMed, Springer, ProQuest, Elsevier and Eric in 2008 until 2018. The materials screened through keywords such as; executive function intervention, near and far transfer effect, cognitive program, generality of cognitive intervention effects, intervention, working memory, inhibition, switching, shifting, memory updating, executive control, cognitive control, strategy based training, process based training, multi domain training. Result of these searches was 113 researches. For determining the main sample, abstract and full text of researches and methodological and interventional aspects of those, was investigated. The quality of the articles was evaluated by checklist of critical appraisal of controlled randomized trials research (Public Health Resource Unit; 2018). Finally 16 experimental researches (controlled randomized trials) as main sample selected.

The present study introduced 18 variables that affect the success and generalizability of interventions, which can be categorized into three groups: Program conditions, Task characteristics, and Participantschr('39') characteristics. Training program conditions contains; type of the training regimes (including process–based, strategy–based, and multi–domain training), the intensity of the training regimes, duration of per training session, Total amount of training, per Session duration, Frequency of training session training in per week, training sessions interval) are effective on the success and generalizing of the program. Tasks characteristics including; quality and material of tasks, a number of exercises per task, general and specific domains of tasks, the optimal level of challenging tasks and the adaptation of the level of difficulty of tasks for each person have been considered in the designing of interventions.  Participantschr('39') characteristics including; sample age, baseline intelligence and cognitive abilities of the individual, the baseline ability of participants in training variables, the number of training gains in training tasks, attitudes toward tasks, perceived difficulty level from training tasks, individual motivation, and age interactions with training regimes are other effectiveness factors.

The literature review suggests that internal researches have taken steps towards investigating the effect of different variables on the efficiency and generalizability of cognitive interventions to near and far goals. In order to, researchers should be doing more efforts instead of applying commercial intervention programs that have public content, do more efforts to design interventions using Specific assignments that are tailored to the cognitive domain–general and domain–specific factors of the goal.