How Biometric Information, Primarily Electroencephalograms can be used to control and enrich user experience within virtual reality.

University of Brighton - Danny Barber

Abstract. A major emerging trend within the video game and entertainment industry is immersion in virtual reality. Companies are constantly striving to create new technologies and modify existing ones. Technologies that output biometric information have been around for decades and have been used in a wide range of practices, however they had not been utilized within video games until recent years. The main need for this technology in years to come will be from enhancing and enriching virtual reality beyond that of regular controls that the public have become accustom to.

  1. A brief history

Biometrics is a derivative of the Greek words ‘bio’ meaning life and ‘metrics’ meaning to measure. Biometrics as we know it today is mainly regarded in terms of measurement that can be recorded and compared with set universal values, however biometrics has been around for thousands of years. This can be seen in caveman handprints as a handprint is a measurable output of a human being.

As human population started to increase rapidly around the 1800’s as a result of the industrial revolution, the need to identify individuals was needed more than ever. One of the first methods used to identify people was known as anthropometrics which was the measurement of different body parts such as the arms, legs, fingers etc. Another method which is still in use today is the use of fingerprinting by police departments around the world. This is a particularly good way of identifying individuals as no two pairs of fingerprints are identical, not even that of identical twins.

Much more concise and accurate systems started to emerge after around 1970 when computer systems became more prominent. It was around 1990 that the biometrics research industry started to grow rapidly and around the early 2000’s when working technologies started to be sold to the general public. [2]

  1. What defines Biometric information?

A biometric identifier is anything that can be measured in regards to a human’s body. Biometric identifiers are usually split in to two categories. The first is Physiological which is measured purely by biology; these include Brain waves, EEG, fingerprints and retinal patterns. The other category is behavioural, which is a trait that has been acquired over time and is influenced by the external environment such as speech patterns and signatures.

It is possible for both categories of feedback to be used in virtual reality. The main category that virtual reality in video games will utilise will be physiological identifiers as they are much easier to detect and measure.

  1. Electroencephalogram (EEG)

The electroencephalogram was invented by Hans Berger, who recorded the first human EEG in 1924. [1] Iancovici, Osorio, Rosario describe an EEG as “a graphic representation of the potential difference between two different cerebral locations plotted over time” The EEG data is recorded using many different electrodes attached to the scalp. The results of which are shown in figure 1.

Fig. . An image of the result of an EEG. [3]

The EEG uses bioelectromagnetism (bioelectricity) which refers to the electromagnetic fields that organisms, living cells and tissues output. The main problem associated with getting these outputs is that “For an electrical signal to be strong enough to be detectable many neurons must fire synchronously and be aligned in parallel so that they summate rather than cancel” [4]. The changes seen on EEG’s are from external stimuli which increase or decrease the action potential of neurons are known as Event-Related Potentials (ERP). These ERP’s are triggered through sensory, cognitive or motor events such as a thought or movement [5].

ERP’s are classified using the polarity of their peak in electrical output and the length of time taken for the potential to occur after the event [1]. For example a P400 classification would mean the polarity was positive and occurred 400ms after the event took place where as an N200 would be a negative polarity 200ms after the event took place.

Electroencephalograms are just coming on to the public eye with regards to the games industry and have been used since 2004, however this technology is still very much experimental. The first Electroencephalogram to be integrated into a game was OpenEEG which was released as an open source project. The source code includes a game in which the player balances a ball.

  1. Galvanic Skin Response (GSR) and Heart Rate Variability (HRV)

Galvanic Skin Response or GSR for short is a method of measuring electrical conductance of skin which is affected by moisture produced by sweat glands. GSR can be used to measure “Physiological arousal”. GSR could be implemented in games in a number of ways which have not successfully been implemented yet. It could be used to measure the amount of stress, pressure or fear on a player who is asked a series of questions. It could also be used to measure anything that causes the player to sweat more than usual.

Heart Rate Variability or HRV for short is used to measure the time between heartbeats. HRV could be used in similar ways to GSR as it measures emotional arousal of the player which is most traditionally seen in times of stress and anxiety.

  1. Hardware used within the games industry
  2. Introduction to Hardware

Over the last 10 years EEG’s have started to be integrated into and sold to low cost research consumer markets. These EEG’s are simply miniaturized relatively low costing medical grade hardware. There have even been some commercial units built by some companies over the last couple of years.

5.2Method of implementation

The method used in EEG’s which is most widely used is the ten-twenty electrode system outlined by the International Federation of Societies for Electroencephalography and Clinical Neurophysiology. This system is based on the naturally occurring landmarks of the skull: The nasion, inion and the left and right preauricular points.

Fig. . In order left to right: Lateral view, Frontal view, and Superior view of a skull. [7]

The first measurement is taken from the nasion to the inion, located along the top of the skull, which is then divided in to 5 separate regions. The first mark (Fp) is placed at the 10% mark; the remaining four are placed at 20% marks (F, C, P, O). See Fig. 2 first image).

The second measurement is taken from the left preauricular point through the C mark to the right preauricular point. A mark is placed at 10% of this measurement over the preauricular points which is labeled T. Further points are marked at 20% intervals which are labeled left and right C. (see Fig. 2 second image)

The final measurement is a circumferential measurement taken over the temporal lobes from the midline Fp position to the midline O position. Marks are made at 10% of this position on the left and right Fp position. Then at 20% marks which are labelled F, T, T on the left and right sides of the Fp position. A final mark is located at the remaining 10% mark labelled O on both the left and right of the Fp position(See Fig. 2 third image)[7]

5.3Commercial hardware used in games

OpenEEG and ModularEEG.

OpenEEG is an open source project that released ModularEEG which is “a device made up of two or more EEG amplifiers and a 6-channel signal capture board that connects to a PC via a standard serial cable. The standard setup has two EEG channels.” It was the first commercially available hardware which allowed use within games and was first demonstrated with a game where a player must balance a ball. [6]

Emotiv EPOC.

Emotiv EPOC is by far one of the most popular and well integrated pieces of technology used in the video games industry. It can be wirelessly connected to a Windows PC. It not only measures the player’s brain waves but also facial expressions. It uses 14 electrode Inputs rather than the medical standard 19 and comes with a two axis gyro which measures the angular velocity of the player’s head. The technology was demonstrated at the 2008 Game Developers Conference in San Francisco where the user demonstrated the technology being used to complete a puzzle game where the player has to rebuild the Stonehenge. Fig 5. shows a user tester wearing the Emotiv EPOC. [8]

Fig. . User tester wearing the Emotiv EPOC controller [9]

  1. Who would use EEG controllers?

EEG controllers, because of their ability to control video games with the mind, do not require hands or any motor skills at all to use. For this reason, patients or players that are paralyzed that cannot use conventional controllers such as gamepads and mouse/keyboard input will be able to play games using their mind.

Alternatively people that aren’t paralyzed nor have a disability discouraging them from using conventional gamepads will also use EEG’s as they enhance and build on methods of virtual reality and augmentation that are already existent.

  1. Conclusion

The potential in the near future for the use of biometric information within virtual reality and video games is massive. Although the technology needs to be refined and made more viable to the consumer markets it has already proved that it has the potential to become a major player in the video games industry.

For EEG’s, GSR and HRV’s to become popular among video game players they must offer something that cannot be replicated with existing technology as well as some decent, well thought out fun titles for users to play as there will be no motivation to invest in such technology when there is nothing worthwhile it can be used for.

There has not been much research in to the technology in a long term environment within games. There are not expected to be any side effects that could be related to bad heath associated with the technology however testing is needed. EEG’s and other input methods that require taking information from how the body reacts is likely to cause much more psychological stress than standard conventional controllers. Iancovici, Osorio, and Rosario use a good analogy to describe this type of stress:

“While it may be possible to create a car driving simulation where the speed of the caris controlled by GSR and HRV, such applications are impractical. Drivers, who are used to controlling a car’s speed via the gas and brake pedals, would unnecessarily experience a high learning curve when trying to “re-teach” their bodies how to drive a car. This design would put immense pressure on one’s body, where the safety of the driver now depends on his or her ability to control his or her involuntary bodily functions.”[1]

  1. References
  1. Tom V. Iancovici, Sebastian Osorio, and Bonie Rosario, Jr(2011). Biofeedback in Virtual Reality Applications and Gaming. Massachusetts: University of Massachusetts. Available at: < [Accessed 12 November 2012].
  2. National Science and Technology Council (2006). Biometrics History. [ONLINE] Available at: [Accessed 20 November 2013]
  3. SUNY Downstate Comprehensive Epilepsy Center. 2013.SUNY Downstate Comprehensive Epilepsy Center. [ONLINE] Available at: [Accessed 12 December 2013].
  4. The Student's Guide to Cognitive Neuroscience 2nd Edition - Jamie Ward - Google Books. 2013.The Student's Guide to Cognitive Neuroscience 2nd Edition - Jamie Ward - Google Books. [ONLINE] Available at: [Accessed 12 December 2012].
  5. Event-Related Potentials: A Methods Handbook - Todd C. Handy - Google Books. 2005.Event-Related Potentials: A Methods Handbook - Todd C. Handy - Google Books. [ONLINE] Available at: [Accessed 13 December 2012].
  6. The ModularEEG. 2013.The ModularEEG. [ONLINE] Available at: [Accessed 19 December 2012].
  7. Transcranial Magnetic Stimulation: Supplement to Clinical Neurophysiology Series - International Federation of Clinical Neurophysiology, G. Deuschl, A. Eisen - Google Books. 2013.Transcranial Magnetic Stimulation:[ONLINE] Available at: [Accessed 04 January 2013].
  8. Emotiv | EEG System | Electroencephalography. 2013.Emotiv | EEG System | Electroencephalography. [ONLINE] Available at: [Accessed 04 January 2013].
  9. IGN Coverage of Emotiv EPOC's game, (2008),EPOC IGN[ONLINE]. Available at: 04 January 2013].