# Implementation and Evaluation of a Serious Game for Working Memory Enhancement
## 1 Introduction  
Over the last few years, brain functionality and cognitive skills have been in the center of interest. Moreover, various studies and research have been carried out and are still taking place to identify best practices and evidence which will offer better training and enhancement of the human brain [1; 2]. Although evidence so far indicates controversial results, it is claimed that training Working Memory (WM) can affect a person's overall cognitive skills and intelligence.  
As we move towards an era where people have to deal with a plethora of information and process data in sectors such as the daily routine, workplace or even at school, it is crucial to be able to store and manage all this information, using it effectively as needed. Moving from school towards a professional career, someone must maintain strong brain functionality and develop advanced cognitive skills (e.g., problem-solving capability, novel thinking, strategic leadership, emotional intelligence and adaptability). Starting from a young age, children also are required to develop higher mental abilities to be successful and perform at maximum level, so that they can prepare themselves for a professional career afterwards [3; 4; 5].  
Another key challenge, which is related to brain functionality, refers to mental disorders caused by the normal ageing of the brain (excluding dementia, Alzheimer's disease, strokes or any other diseases which cause more severe mental deficits). The older someone gets, the more likely they are to present reduced brain functionality, since the human brain tends to shrink over the years [6; 7]. The challenge here is that older people should be able to preserve their mental abilities and prevent cognitive decline in order to be able to function and live on their own.  
Training and improving cognitive skills are possible based on the theory which claims that the human brain is characterized by the presumed \"neuoplasticity\"--the ability to create and form new neurons and building or even reforming the interconnections between them (called synapses) [8; 9; 10]. In recent years, psychologists have managed to develop several batteries which train and stimulate the human brain by utilizing certain cognitive exercises, and there is continuous interest and research on how to exploit these practices and apply them through intervention programs aimed at brain strengthening, delaying cognitive decline and leading to overall better quality of life [11; 12; 13; 14; 15].  
This research describes the design and implementation of a Serious Game (SG) for WM training, its final evaluation regarding its effectiveness as a training tool for WM and its usefulness and enjoyment evaluation as an SG as well, through a study with 40 participants in a 7-week intervention program. The results showed that users with high pre-test scores preserved their performance with no further improvement, but for those who had scored lower in the pre-test, there was a notable increase in their performance. Additionally, all users found the game useful in WM training and enjoyable as well.  
The following sections contain the theory behind WM training and SGs, which the game was based on, followed by the description of the study, the tools and instruments used, along with the evaluation process and finally the results.