Keywords

1 Introduction

Computer-based cognitive rehabilitation programs such as PSSCogReHab, RehaCom, and COMCOG have been developed since the 1980s and utilized in many neuropsychological tests. Although they are useful in proving mild cognitive impairment, they are limited in identifying normal aging, mild cognitive impairment and dementia separately from each other as there are many common aspects among those. The possibility, however, has been presented that cognitive rehabilitation therapy is capable of not only slowing the progress of cognitive dysfunction, but also improving concentration and memory, enhancing cognitive functions such as daily living activity [1, 2].

In memory training, in particular, the therapy was found effective in improving working memory capacity, processing speed, etc. It was found as one of the factors capable of preventing or, at least, minimizing memory functional weakening to learn memory strategy necessary for information encoding and retrieval. Activities seeking brain stimulation such as learning a new language or gaming were said to function as a protective factor against degenerative dementia or Mild Cognitive Impairment (MCI). It was also reported that the cognitive perceptual factor of stroke patients was highly correlated with their activities of daily living [3, 4].

Such computer-based cognitive rehabilitation programs allow to change rehabilitation training items and computerized the test taking and scoring procedures, easing the comparison between the present and past results through the qualitative scoring of task outcomes. In addition, they can store and convert data, measure and analyze responses to each area, and easily reproduce the measurement. However, most of the computer-based cognitive rehabilitation programs proceed game in a consecutive and repeated manner to dampen user interest and hardly inducing their voluntary participation for the thought that they are receiving repeated evaluation.

Against this backdrop, this present paper developed a functional game (serious game) encompassing diverse cognitive functional areas for patients with degenerative dementia or MCI by taking the merits of the computer-based cognitive rehabilitation programs; and suggested an integrated cognitive rehabilitation management service model capable of recommending an appropriate game based on the results while user training. The functional games proposed in this paper are centered on the frequently utilized neuropsychological test of RehaCom and divided the cognitive functional areas into 5 areas under hierarchical classification. They were further developed again by subdividing the training areas. Moreover, since most of the users are the elderly, the system interface was designed with the focus on their convenient use.

2 Cognitive Functional Area-Specific Contents Building

In this paper, the main cognitive functional factors were categorized into 5 areas – attention, memory, orientation, executive function and activities of daily living (ADL). According to the categorized areas, contents were produced as shown in Fig. 1.

Fig. 1.
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Produced contents of each cognitive functional area (Color figure online)

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2.1 Contents for Attention

In the contents of Selective Attention, letters are presented at the center of contents based on the color and word test utilizing Stroop effect designed by J. R. Stroop, an American psychologist; and users are made to select colors appropriate for the meaning of the word, regardless of its colors [5]. With respect to the difficulty level structuring, figure forms were made in quadrangle, pentagon and hexagon to increase nontarget stimulation to users, helping amplify semantic interference effect [6].

In Sustained Attention, based on the existing SIMON game, users remember the order of colors of figures in diverse colors presented in random order then, recall them and touch the button of colors in the same order. This is an effective method to increase the working alliance referring to the relationship between a therapist and patient [7]. With respect to contents progress, in the case of positive response, the number of presented colors increases continually and, in the case of wrong response, the game is ended.

Divided Attention is the highest level among the three types of attention and means the ability to perform multiple kinds of tasks simultaneously in a certain condition [8]. In this paper, users were made to cognize spatial pattern by assessing symmetry of both sides; remove it; and remember the number presented upon the removal to perform multiple tasks at the same time. If a user enters filling on the right side of the screen to mirror the dough pattern on the left side, a well-baked fish-shaped bun is made. If there is no filling in the symmetrical place or filling is placed in a wrong spot, a burnt fish-shaped bun is made. Additionally, users were instructed to remember the number of fish-shaped buns their guest wanted to buy so that they can perform divided tasks as well.

Attention is to select randomly-presented numbers following the rules such as the ascending order or descending order, and even or odd number. Difficulty level was differentiated according to the digit of presented numbers or their size or number change.

2.2 Contents for Memory

Memory is the ability to store and maintain information such as perception or experience at a certain point and recall it as necessary. In general, memory consists of four steps of attention, encoding, storage and retrieval. These processes are known to be intercorrelated [9]. In this study, based on the preceding study results on memory, 7 areas were recognized.

Topological memory is the ability to remember the location and space of a perceived target. A card matching game was included, which is a main topological memory content where players find out the location of identical figure. For the card matching game, flower cards were utilized as they are familiar and easily understood by Korean elderly people. Multiple pairs of flower cards are shown for a certain time in random locations; then they are flipped over for users to find out the same pairs within the shortest time possible.

Associative memory refers to the ability to encode and store visual and linguistic stimulations then, retrieve the other stimulation through one of the two stimulations. The content for this was set up to make users remember the faces, names and characteristics of many people shown for a certain time then, match the randomly-rearranged faces with the names based on their memory.

Verbal memory is the ability to recall information at verbal stimulation. This study employed the Cerad-K word list memory test and word list recognition test protocol in producing the content [10]. Random syllables and words were presented for a limited time and users selected the previously-presented syllables and words on the list of mixed words. Since the object to remember is words, difficulty level was differentiated according to the number of presented syllables and words.

Immediate memory is part of short-term memory to keep the information received from sensory memory for a while. The content was set up by letting users remember the forms and colors of figures in cards presented first and judge if they were identical to the forms and colors of figures in card presented subsequently.

Visual short-term memory is the ability to recall information on visual stimulation within a short period of time. The content in this paper was structured based on Change Detection Task [11]. An object is shown for a certain time at a random location on screen. After it disappears, a user detects and selects another kind of added object to a new location in this game.

Working memory is the ability to remember information for a few seconds, utilize for operation information remembered in the process of thinking. The content consisted of three activities – star sign marking, N-back training and sequence memory [12, 13]. Among the trailing marking test, the star sign marking bases on visual and motor detection functions. When stars with number marks are shown in random spots on screen, users should connect the stars in the ascending order from number 1. N-back consists of the 3 aspects of color, voice and location for visual, acoustic and spatial recognition training. Users recall their response to the stimulation N times earlier back in sequence. Difficulty levels are adjusted according to the increase in N, representing how far a user should remember back in sequence.

Sequence storage is similar to SIMON, the Sustained Attention content mentioned above. It is to remember the order of colors shown in a random order and choose the color of figure appropriate for the number presented at the center of screen.

Recall memory is the ability to communicate one’s past experience to another person through the cognitive process, emotional process and verbal process. It is to recall again the information on things once experienced. The content was structured to make users recall once well-known persons, events, songs, etc. in the past.

2.3 Contents for Orientation, Executive Function and ADL

Orientation means to perceive the three dimensions of time, place and surroundings of oneself at the present time. The content was established with questions on things and jobs easily accessible from surrounding people and daily lives. Orientation on surrounding people, in particular, is in the form that a guardian or therapist enters the photographs and information on people around a user; multiple choice questions are established based on it; and the user answers the questions. Since orientation is the training of long-term memory, no time limit was set so that patients could have enough time to recall and think.

Executive function is a high-level cognitive ability to adjust one’s thoughts and behaviors in line with environment. Executive function can be divided into working memory, inhibitory control and cognitive flexibility or shifting. As in Fig. 1, response inhibitory ability content was established with the mole catching game based on Go, No-Go Discrimination Task [14].

Activities of daily living (ADL) means the ability to independently perform the basic daily activities to take care of oneself as well as the complicated daily activities to maintain social life. The content consisted of grocery shopping, calculating, etc. In the grocery shopping, when a list of random items to buy is presented, users have to buy the right items accordingly. Difficulty level was adjusted according to the number of items to purchase. In the calculating, a receipt is presented, and users have to choose the right bills and coins shown in the bottom of the page accordingly and receive the right amount of change. Difficulty level is adjusted according to the number of items on the receipt.

3 Integrated Management Program

3.1 Composition of Integrated Management Program

In this paper, an integrated management program was designed to reflect the cognitive function level of users according to cognitive function evaluation results in recommending cognitive functional areas to train and detailed training contents. Computerized mini-cognitive function test was constructed based on the MMSE-KC (Mini-Mental Statue Examination-Korea Child). To this end, users were instructed to enter their name, sex, age, academic background (number of education years), etc. [15]. A total of 19 sets of question text were included on orientation, memory registration, attention and working memory, delayed recall, verbal ability, constructional praxis and judging ability. The results were reflected in the contents of 5 areas recognized in this paper to recommend content difficulty level to users. The results are visually presented in pie chart and line graph for users to easily understand their score distribution. The block diagram of integrated management program, produced user interface and result pages are shown in Fig. 2.

Fig. 2.
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(a) Diagram of integrated management program (b) user interface (c) result page

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4 Conclusion

Computer-based cognitive rehabilitation programs have been researched in many studies so far and their effect and usability have been proven and developed in various forms. However, they have not assessed different levels of people’s cognitive function and provided games simply in a consecutive and repeated manner to lose users’ interest and face limitation in inducing their voluntary participation.

In this paper, the areas of cognitive rehabilitation programs were categorized into 5 areas of attention, memory, orientation, executive function, and activity of daily living with the focus on RehaCom, a frequently-utilized neuropsychology test. Each of the 5 areas were further divided for more effective training. In general, contents were made to reduce user impression of being tested while encouraging their interest in participation. Moreover, in order for therapists to more conveniently perform the cognitive functional test and management, MMSE-KC-based cognitive function evaluation tool was computerized and, based on its results, an integrated management program was designed, which is capable of recommending contents for cognitive functional areas with low scores. In particular, the contents produced in this paper were constructed by focusing on the followings to help enhance users’ interest and engagement.

First, in developing a functional game, Korean cultural elements were applied to contents so that the program users feel familiar. Second, each game has different background music and sound effects to give acoustic feedback inducing user engagement in the contents. Third, as most of the users are elderly, touch screen-centered visual screen composition was constructed in the user interface for their convenient use. Forth, for their easy reading and understanding of change in results according to the number of content taking, it was visualized in pie chart and line graph to help improve users’ achievement. Fifth, in reflection of users’ cognitive functional test scores and training result scores, sub-area-specific contents were recommended to users in a non-consecutive way to help ease the sense of being bored from repeated task implementation.

It can be stated that the integrated cognitive function management program developed as such has the strength of checking a user’s cognitive function level and training him or her with contents suitable for own level any time if user cognitive functional test and training contents are available. Moreover, since most of the cognitive rehabilitation training contents are, so far, those in a few cognitive function areas only; the 5 areas presented in this paper are expected to support cognitive rehabilitation training in further diversified areas.

To expand the cognitive rehabilitation training effect, further study can make use of big data to analyze plenty of result data in recommendation for more effective and user-customized service provision.