How the Emotiv EPOC Works

­If you've read How Your Brain Works or have ever taken a psychology class, you probably know that your brain is home to billions of neurons, which are nerve cells. Using electrical impulses, they send messages to and through each other. Whenever your brain is working (and that means always, even during sleep), all these messages firing from neuron to neuron amount to an electrical current.

Although the brain continues to be an enigmatic subject of study, scientists have known about brain waves, which are a map of the electrical current firing from neuron to neuron, for a while. British physician Richard Caton first noticed the brain's current in 1875. By 1924, German neurologist Hans Berger found a way to read the current by developing what's known as an electroencephalograph. This kind of machine produces a graph measurement of brain waves, known as an electroencephalogram (EEG).

The system involves hooking up several pairs of electrodes on a patient's head. These electrodes are disks that conduct electrical activity, capture it from the brain and convey it out through a wire to a machine that amplifies the signal. Scientists attach electrodes in pairs on the head because they're measuring the difference in voltage between the pair. Soon after starting his research, Berger noticed that the electrical activity of brain waves correlated to a person's state of mind.

­As we mentioned, your brain fires out this electrical current even when you're sleeping. Your brain waves are usually slowest during sleep. However, slow is relative. In deep sleep, the brain transmits delta waves, which fire one to four times per second. In light sleep, theta waves fire about four to seven times per second. Alpha waves, which we emit when we're in a relaxed, conscious state, come next at about seven to 13 pulses per second. Lastly, beta waves, which reflect a very excited or stressed mind, fire fastest at 13 to 40 times per second. Your brain doesn't emit just one kind of wave at one time; rather, it emits multiple kinds of waves simultaneously. Nevertheless, one kind of wave can dominate in a given moment.

­Today, doctors are able to use EEG tests for a variety of applications, such as diagnosing epilepsy as well as other seizure disorders. The test is appropriate for diagnosing epilepsy because the everyday brain wave patterns of patients with epilepsy tend to be abnormal. EEG tests can also reveal sleep disorders, tumors and the effects of a head injury or determine whether a coma patient has become brain dead.

OK, so the medical uses of EEG are all well and good, but what does this have to do with video games and the Emotiv EPOC? Find out next.

As electroencephalogram (EEG) readings get more sophisticated and our understanding of the brain advances, scientists can delve further into the meaning of the scratchy graph. If the test can convey more than just the evidence of a medical abnormality and actually interpret a patient's thoughts, it can have wider implications. If you remember, the presence of beta waves indicates that a mind might be particularly excited or stressed. It turns out that people emit certain patterns of brain waves in conjunction with particular emotions or even thoughts.

Researchers have been working to develop EEG technology specifically for people living with loss of muscle control. The idea is that, when the technology is perfected, patients with paralysis will be able to control things through a computer using only their thoughts. They would be able to type e-mails or adjust the thermostat with mere concentration [source: Singer]. Another application can offer a person suffering from paralysis a virtual reality and an avatar through which he or she can move vicariously.

­ Emotiv Systems, the company behind the new EPOC, has applied this technology to the gaming world so everyone can experience it. The company claims it has developed the first high-fidelity brain computer interface (BCI) that reads and interprets both conscious and nonconscious thoughts as well as emotions [source: Emotiv]. The headset also processes facial expressions. According to Emotiv, the range of the system spans 30 different expressions, emotions and actions. The emotion of boredom, the facial expression of smiling and the thought of pulling are just a few examples of things the system picks up on and translates to your avatar's actions on the screen.

­­The EPOC headset incorporates 14 extensions of electrodes (seven pairs), mostly centered around the front of the scalp. But rather than using the wires of traditional EEG tests, the headset is completely wireless, allowing the player free, natural movement. To go along with that, the headset also includes a gyroscope that allows the player's head motions to control the camera or curser. In a doctor's office, it might take a sticky gel to keep the electrodes in place, but the EPOC headset fits on your head similar to the way headphones do. The system costs significantly less, too -- instead of the tens or hundreds of thousands of dollars that EEG machines usually cost, the EPOC costs only a few hundred [source: della Cava].

But all people seem to have unique patterns of brain waves. So how can the Emotiv EPOC read yours? We'll find out next.

­Whenever you're frustrated, your mind emits a particular pattern of brain waves. And while the pattern might stay consistent, it's probably a little different from the pattern another person emits whenever he or she gets frustrated. Because all brains are unique, the Emotiv EPOC has to get to know your brain before you can get your Luke Skywalker on.

First, as you're putting on the headset, you need to finagle the electrodes to make appropriate contact with your head. Because it doesn't use the adhesive material of medical electroencephalogram (EEG) machines and the headset is meant to fit all sizes, you need to arrange the electrodes manually until they're just right. Refrain from making jerky movements to avoid disconnecting an electrode. Bundled along with the Emotiv EPOC headset is a game in which you're challenged to perform tasks for a sensei. In this game, you're told to practice concentrating on a specific motion, such as lifting. The headset's electrodes record the resulting brain waves during your concentration, and from then on, the system recognizes that pattern as the lift function. Concentration is key, which can be challenging. Creators of the system recommend that you physically pantomime the motions so that you stay focused on the task at hand and are able to repeat it later in the game [source: Edwards].

A few of the actions the game asks you to practice and perform are:

Other aspects of the EEG readings don't have to be quite so unique to you to work. For instance, the system can pick up on general boredom even if it hasn't asked the player to practice boredom before. The system recognizes that if you're emitting more theta waves than usual, you're basically zoning out. The system can respond by ramping up the excitement in the game [source: della Cava].

Some emotions it reads are:

Aside from actions and emotions, remember that the headset can also read facial expressions. As you wink or frown, a corresponding cartoonish face on the screen mimics the action. This can be incorporated into the game as well. In demonstrations of the game, players are shown scaring away fanciful creatures by grimacing.

Here are some of the actions Emotiv says the headset can read:

What does the future look like for this technology? While some consider the EPOC just fun, games and Jedi mind tricks, others see this technology as having far-reaching implications -- some good, some bad.

Emotiv hopes the excitement about its thought-controlled gaming technology will live on forever in the Emortal, an online portal for players. Here, people can walk through a cityscape and find new applications and games to download. They can also encounter community spaces and chat with other players. People can even upload their own music and photos on the Emortal.

­If the EEG gaming technology eventually catches on, it could revolutionize the way people think about video games in much the same way the Nintendo Wii did (or perhaps more). On the one hand, with its facial expression interpretations, the Emotiv EPOC attempts to close the gap further between the real world and the virtual world to create a more realistic experience, much like the Wii does. On the other hand, the Emotiv EPOC also tries to bridge the gap between human thought and the outside world to create an experience that's less like reality and more fantastical and dreamlike. The technology behind EPOC eliminates the middleman of motion altogether -- a staggering thought to consider.

It makes sense, then, that Emotiv and IBM have announced they want to pursue the possibilities of this technology beyond just the world of video games. One idea is that people would be able to experience realistic virtual training with the Emotiv technology. Time will tell if the EPOC and similar technology will extend beyond the gaming market or even permeate the gaming world at all.

But not everyone is as excited as IBM to see the world dive into this kind of technology. Though there are certainly plenty of gamers who are excited to usher in an age of thought-controlled video games and interfaces, there are others who find the whole idea, and even the ex­perience of playing it, "unnerving" [source: Reed]. Some question the possible harmful applications of such devices. Should researchers continue making more breakthroughs to advance EEG technology, it could plausibly lead to computers that can, in essence, read someone's mind. Those with the technology could be privy to the private thoughts, opinions and emotions of others. Granted, this could be very far off, considering where the technology (and our understanding of the human brain) is now. Nevertheless, we can't rule out the possibility entirely. Perhaps we shouldn't dismiss the prospect of Thought Police (like that in George Orwell's "1984") as mere alarmism.

Regardless, if you're just interested in developing the Yoda in you and lifting rocks with your mind, you can expect the Emotiv EPOC to come out in 2009, for an expected cost of about $299.