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Books - Brain-Computer Interface

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Brain-Computer Interface

  • Availability
    Clinical trials
  • Used to treat
    Stroke
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BCI-01-tmb
A person connected to a BCI looking at a screen displaying her brainwaves.
BCI-02-tmb
A patient using a Wadsworth BCI system.

A Brain-Computer Interface (BCI) is a system that allows you to interact with a computer by means of your brain signals. The system typically consists of a computer, an amplifier and a skullcap. The BCI reads off brain signals and transmits them directly to a computer, bypassing the neuromuscular system through which we usually interact with the world. In other words, all you have to do is to focus on a task you wish to accomplish; the brain-computer interface ‘understands’ your intention on the basis of your brain activity and translates it into output on a computer.

For example, it is possible with currently technology to type letters into a word processor using thoughts alone. You simply concentrate on the letter you wish to type and it will appear on a computer screen.1 If you have a severe motor disability, brain-computer interfacing might allow you to do things that would otherwise be impossible, thereby enhancing your quality of life. You could potentially control a computer cursor, for example, or use a word processor to access the Internet and various forms of environmental control, such as light, temperature and entertainment. Another possible use relates to prosthetic limbs: if the BCI is connected to a prosthetic arm, you might be able to move that limb with your brain signals. A third area where brain-computer interfacing could also be used is in controlling a motorised wheelchair.2 It may even be possible to use brain-computer interfacing in a rehabilitative way, to restore motor functions.3

There are two different ways a brain-computer interface can record brain signals, each corresponding to a different level of invasiveness.4 The first - non-invasive - way uses a device that you place on your head like a cap. It reads off brain signals from your scalp. It is easy and safe but limited in terms of the frequency and resolution of brain signals it can pick up. The second - invasive - way requires implantation of electrode arrays, either at the cortical surface or within the brain. This method is better for picking up brain signals but there are concerns about safety, risk of tissue reaction and long-term recording stability. According to medical researchers Daly and Walpaw (2008), the kind of invasiveness suitable for you is dependent on personal circumstances:

'At present, it seems probable that different recording methods will be useful for different applications, different users, or both.’5

Possible benefits of Brain-Computer Interface for stroke

At present, the brain-computer interface is mainly used to allow people with minimal muscle control to communicate. For example, if you have had a brainstem stroke and only have minimal eye movement control, most conventional communication aids will not be useful, as they require voluntary muscle control. A BCI, however, might allow you to use a computer or environmental controls. A second area where BCI could be used is in the rehabilitation of motor functions, e.g. as part of a therapy that ‘rewires’ sections of the brain to perform the motor functions formerly accomplished by the damaged part of the brain. By measuring brain signals with a BCI, patients can be trained to produce more normal brain activity. In this way, the brain can be conditioned to send out the right signals, even if the patient is not yet able to perform the action properly. Together with more conventional methods, e.g. repetitive movement of the affected limbs, this might restore and improve motor control.

In a recent study, a 43-year-old woman, who was 10 months post-stroke, underwent a non-invasive BCI enforced rehabilitation program, with some success.6 She was issued commands to move or to relax her index finger. The BCI could then read her brain signals and tell her if she had intended the right action, even though she was not yet actually able to move her finger. After three weeks of training, the participant had regained some voluntary control of her finger.

Arguments against using Brain-Computer Interface for stroke

There are two main issues with brain-computer interfaces. First, a BCI requires lots of training by the user and the calibration of the computer system. You must train your ability to focus on specific tasks in order to use the BCI, which can be a lengthy process. The BCI also requires constant calibration and technical support. Although the actual equipment is not very dear, the maintenance costs make the treatment time-consuming and expensive. Therefore, the treatment is not widely available at present. To reduce costs, the need for technical support must be minimised and the BCI systems easy to set up and use.7

Second, because current BCIs depend upon visual stimuli and visual feedback, they require the user to be able to see and maintain gaze. If you do not have sufficient visual acuity or gaze stability, you will not be able to use a BCI. The development of systems using auditory rather that visual stimuli is being investigated.8

Case histories

  1. 'Mayo Clinic. "Brain waves can 'write' on a computer in early tests, researchers show"'. In Science Daily, 7 December 2009
  2. ‘Connections that Count: Brain-Computer Interface Enables the Profoundly Paralyzed to Communicate’. In NIH Medline Plus, Summer 2007 Issue, Vol. 2, No. 3, 20 – 21
  3. Thought-controlled wheelchair in Japan

Notes and references

  1. 'Brain waves can 'write' on a computer in early tests, researchers show'. In Science Daily, 7 December 2009
  2. Thought-controlled wheelchair in Japan
  3. DalyJJ, Cheng R, Rogers J, et al. ‘Feasibility of a New Application of Non-invasive Brain Computer Interface (BCI): A Case Study of Training for Recovery of Volitional Motor Control After Stroke’. In Journal of Neurologic Physical Therapy, 2009, No. 33, Vol. 4, pp. 203-11
  4. DalyJJ & Walpaw JR ‘Brain-computer interfaces in neurological rehabilitation’. In Lancet Neural, 2008, No. 7, pp. 1032-43, p. 1033.
  5. DalyJJ & Walpaw JR. ‘Brain-computer interfaces in neurological rehabilitation’. In Lancet Neural, 2008, No. 7, p. 1033
  6. DalyJJ, Cheng R, Rogers J, et al. 2009: The therapy involved is a combination of BCI and Functional Electrical Stimulation (FES).
  7. DalyJJ & Walpaw JR. 2008: p. 1038.
  8. Nijboer F, Furdea A, Gunst I, et al. ‘An auditory brain-computer interface (BCI)’. In Journal of Neuroscience Methods, 2008, No. 167, pp. 43–50.

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