# Implementation and Evaluation of a Serious Game for Working Memory Enhancement
## 2 Theoretical Background
### Serious Games for Supporting WM Training  
There are several definitions about SGs such as that of [PERSON] back in 1970, who related SGs to board and card games whose purpose was not only fun but education as well [28]. Another definition describes as serious the games that set educational goals with an entertaining background [29]. Additionally, [PERSON] and [PERSON] [30] also defined SG as a game whose primary target is education rather than entertainment. An interesting definition has been given by [PERSON], who stated that the serious characterization of a game does not lie on the content and/or its representation but on the goals that it sets and how they are achieved [31; 32]. According to him, personal computers were the medium that transformed an entertaining game into a serious one. Finally, [PERSON] defined SGs as \"a mental contest, played with computer in accordance with specific rules that uses entertainment to further government or corporate training, education, health, public policy, and strategic communication objectives\" [33]. All the previous definitions conclude that the primary purpose of SGs is not pure entertainment; rather that they have an explicit educational purpose and intend to provide certain knowledge to the players that are involved in them. Towards this direction, SGs can be utilized in the learning process, as they provide the ability to create memorable and engaging learning experiences. In addition, SGs can be built on sound learning principles encompassing teaching and training approaches that support the design of authentic and situated learning activities in an engaging and immersive way. Moreover, they may develop and reinforce modern skills such as collaboration, problem solving and communication. For that reason, SG applications have been used in several sectors like education, healthcare, defense, engineering, emergency management and more. Building SGs based on activity-centered pedagogies that enable trainees to engage actively with problems associated with cognitive training and specifically WM training is an empowering approach with benefits for learning as well as for developing a wide range of significant high-level intellectual attributes. SGs constitute probably one of the best ways of building cognitive skills and achieving educational methods attractive for the learner, under suitable conditions. Based on the above, in order to evaluate WM we experimented on a memory game which uses the repetition of paths in order to potentially improve the WM. As a result, the game in question is placed among serious ones, since it tests whether it achieves its purpose or not, apart from entertainment. As mentioned, WM allows the transfer of information into long-term memory and temporarily stores new information, creating conditions for recall--when needed--so that this information can be used or permanently stored [34]. In addition, WM facilitates the maintenance of concentration, building visuo-spatial images in order not to cause cognitive load, which overloads the limited memory so that cognitive functions can be performed more easily. All these directly connect to what has been mentioned regarding the parameters which are important when building a successful SG. WM is a key factor in enabling concentration and preserving data--even temporarily--so that there can be a connection with existing memories or relative encoding, which facilitate cognitive functions. In this way, we realize its significance, which makes it imperative to include it as a point of reference in the design of an SG. Almost all factors that contribute to the successful design of an SG are related directly or indirectly to WM. Therefore, besides the basic design purpose, which is the user's entertainment, WM constitutes another essential aspect which should be taken into consideration. In order to have an effective SG, its goals should be clear and should also apply to every appropriate cognitive/behavioral design principle.