6. Conclusion

5. Discussion

Assistive and Rehabilitation Engineering

responses.

and communication.

ous control signal.

select a color.

188

together and possibly become friends.

world and present an extremely promising interface.

We conducted an impression evaluation of the Brainio Bros 300 cooperative game and its usefulness. First, the results of the SD method showed that the players

"friendly," "lively," "satisfying," and "new," with "cooperative" evaluated particularly highly. On the five-point scale, the game was evaluated highly in terms of both the players' average values and the combined percentages of "strongly agree" and "agree" for the questions of "Interesting," "Communicating with a child," "Game design," and "Would recommend," with "Would recommend" showing a particularly strong correlation. Finally, the opinion that the cooperative aspect of play was interesting was particularly widely expressed in the free

One of the biggest advantages of Brainio Bros 300 is the capability for the player,

The use of a P300 BCI is an easy-to-measure, noninvasive method. It can also be controlled with a high degree of accuracy without the need for detailed user training in advance. Training the P300 BCI command categories does not take a great deal of time. Most patients, including almost all able-bodied people and even people with severe paralysis, can use a P300 BCI. It also offers a goal-oriented control signal that is particularly suited to situations that do not require a continu-

On the other hand, one of the game's limitations is as follows. The P300 BCI is one of the fastest of the currently usable BCIs, but it is still very slow compared to normal input devices such as mice and game controllers. In the current Brainio Bros 300 system, the player must wait for the colors to flash before having the supporter

With the development of a decoding algorithm that could detect the P300 brain

We believe that, in the future, if it is possible to reduce the number of flashes while maintaining the current level of accuracy and to increase the number of commands (controllable dimensions), this type of game would be usable in the real

Some problems with using a P300 BCI are that real-time P300 detection can sometimes be inaccurate, as it is easily affected by a number of human sensory phenomena such as attentional blinking, repetition blindness, and change blindness [24–28]. It is also possible for motivation to impact BCI performance [29], causing the EEG signal pattern to change according to the attention level, fatigue, state of mind, learning, and unsteadiness [1]. A P300 BCI might also not be an effective

wave to a high degree of accuracy after only one attempt, a command could be sent to the game every second. The results could then be adjusted according to feedback following categorization. For example, in the event of a mistaken command, the response time could be minimized by testing the supporter again. This should also allow the result to be checked once per second. Although Brainio Bros P300 is a game in which players and supporters cooperate, it takes time for a supporter to erase blocks by using P300 control as compared to standard games. Moreover, as it is a game in which two people cooperate, it differs from a competitive game based on speed. For this reason, a player and a supporter must play

who does not have to wear an EEG cap, to play together with the supporter, who does wear an EEG cap. We believe that playing cooperative games using a P300 BCI could be of significant benefit to people with major disabilities such as amyotrophic lateral sclerosis (ALS), enabling them to play with able-bodied

children, family members, and friends, thus deepening connections

evaluated the game as "full," "cooperative," "enjoyable," "happy," "cute,"

In this BCI-based game research, we developed a real-time game, Brainio Bros 300, a cooperative game using a P300 BCI to facilitate two users (a player, who controls the character in the game and does not wear an EEG cap, and a supporter, who uses his or her brain activity to communicate) working together to achieve one goal. We evaluated participants' impressions of the game and its usefulness and considered the viability of the P300 BCI interface.

In the future, we would like to use noninvasive measurement to investigate more deeply the brain mechanism during a cooperative video game.
