###### Abstract
However, traditional and conventional systems are characterized as tedious and repetitive, and that strongly affects users' motivation to learn and adhere, which consequently reduces any potential for learning transfer [21; 22; 23; 24]. [PERSON] et al. showed that WM training can significantly improve motivation and training performance, if it is being decorated by GEs [25]. Either utilizing GEs in order to gamify a serious intervention program (gamification) [26] or using certain games with serious goals with entertainment coming as a secondary objective (serious games), the main outcome is to improve WM but with increased motivation and engagement at the same time. In reality, it is often hard to make a clear distinction between gamification and serious games [27]. In general, serious games are full-fledged games that have a typical game structure and, at the same time, add educational value beyond entertainment, and gamification utilizes game-like mechanics and embodies them in traditional methods and programs to increase engagement. Over the past decades, several studies have demonstrated that an increase in WM capacity can be achieved with computer-based (computerized) training. It has been used in adults with the purpose of improving and enhancing cognitive skills, but it has also been applied to children (with typical or atypical development) [5; 12; 28; 29; 30; 31; 32]. The results so far are inconsistent and sometimes controversial, and the main debate is between near and far transfer effects. Most studies have reported that WM training leads to near-transfer improvements (related to the task that is being trained), such as verbal and visuo-spatial WM [5; 12; 32]. However, there are cases with little to no evidence regarding far-transfer improvements (effects in other cognitive functions) [33; 34], and there are fewer cases reporting improvements in other cognitive functions. In particular, a transfer effect was found in attention inhibition, reasoning, reading and arithmetic [13; 35; 36; 37]. In this direction, several commercial training programs have been developed, and their effectiveness has undergonetesting, demonstrating positive effects (Brain Age [38], Cogmed [39], Lumosity [40]) or little to no effects [31; 35; 41]. Utilizing GEs, gamification or serious games allow computer-based interventions to be more entertaining and playful, be easy to comprehend and perform, and offer feedback and reinforcement, and as a result, they foster adherence and motivation, rendering this kind of intervention far better than the traditional, non-gamified programs [26; 42; 43; 44]. The theory behind utilizing GEs in CCT is the Self-Determination Theory [45], which is the most prevalent in the field of gamified learning. SDT defines motivation as comprised by intrinsic and extrinsic motivation. The first one refers to the motivation that is developed when someone performs an activity for its inherent satisfaction and feels the competence during the activity. Extrinsic motivation refers to the satisfaction of performing an activity only for its outcome. Typically, a subject begins with intrinsic motivation, moving to extrinsic motivation until it ends up with no motivation at all for the activity. Intrinsic motivation has a crucial role in adherence and long-term participation in an activity, whereas extrinsic motivation is more suitable for short-term tasks [46]. Likewise, with interaction and collaboration with other peers, the processes of learning and problem solving can be constructive and facilitative, supported by theories such as the zone of proximal development [46] and scaffolding theory [47]. Defining GEs is difficult since there is no commonly accepted definition. Generally, such elements may include components such as points, badges and leaderboards, and mechanics such as competition, challenge and win state. It is worth mentioning that game components are often mistakenly overlapped by game mechanics.