## 2 Materials and Methods
### Data Analysis  
Data collected during the study were analyzed using SPSS Ver. 23.0 program (SPSS Inc., Chicago, IL, USA) with a two-sided test at a statistical significance level of 0.05 [28]. Figure 3: The types of story-based game content and performance evaluation. **(a)** Thrilling Glass Bridge (selective attention): A game in which animals appear at the center and move while continuously switching positions with three other animals listed in front. The task requires players to identify and match the animal at the center with those in the sequence. **(b)** Whirling Space Journey (sustained attention): Players observe a changing environment and select only the items that match the ones displayed on the right. These selected items are then guided through the parallel lines of two spaceships. **(c)** Cosmic Voyage (object recognition memory): While monitoring a dynamic space environment, players must move the left or right spaceship to collect only the items that match the one displayed in the center. **(d)** Find Friends on the Glass Bridge (visual perceptual memory): A game in which players adjust the sequence of three animals in a farm setting to match the order in which animals appear, accounting for continuous changes. Figure 2: The quiz content type and performance assessment details. **(a)** The Moment of Decision: A game in which participants must press the button corresponding to the direction (left/right) of the card matching the shape displayed in the center within 60 s. **(b)** Keen Observation: A task in which images are presented alternately and randomly at the top or bottom of the screen. Participants must respond with O or X based on whether the image in the specified direction (top or bottom) matches the given criteria. **(c)** Odd or Even Words: A task where numbers or letters are alternately and randomly displayed at the top or bottom of the screen. Participants respond with O or X depending on whether the number or letter in the specified direction (top or bottom) matches the criteria. **(d)** The Special Me: A game where participants identify the one shape among nine displayed on the screen that does not follow the same pattern. Efficacy evaluations were conducted using both modified intention-to-treat (ITT) and per-protocol analyses, with the final determination of clinical trial results based primarily on the modified ITT analysis [29]. The modified ITT analysis population included participants who were randomized, provided with an investigational digital device, and had post-baseline data available for primary efficacy evaluation variables. The per-protocol analysis population was derived from the modified ITT group and included participants without major protocol violations (e.g., early withdrawal, violation of the inclusion/exclusion criteria, or randomization errors). The participants were also required to have a treatment adherence rate of at least 80%. For participants with missing data for efficacy evaluation variables due to dropouts or other reasons prior to the conclusion of the clinical trial, the last observation carried forward method was employed to replace missing values with the most recently recorded data (i.e., from the last visit) [30]. Missing data handling was applied only to the modified ITT population, whereas the other items were analyzed using the available dataset without imputing missing values. A safety evaluation was conducted for all participants who were enrolled in the clinical trial and received at least one application of the investigational medical device. The general characteristics of the participants were analyzed using frequencies and percentages, as well as means and standard deviations. A homogeneity test for the general characteristics of the experimental and control groups was performed using [PERSON]'s exact test. For the homogeneity test of the dependent variables, \(t\)-tests were used if the data followed a normal distribution, and the Mann-Whitney U test was applied if the data did not follow a normal distribution [31].