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Tricky Interfaces: Brain-Computer Interfaces Are Still A Long Way Off

Brain-Computer Interfaces
Tricky Interfaces: Brain-Computer Interfaces Are Still A Long Way Off
Neurology

It will still be a long time before brain-computer interfaces are able to read thoughts. And many limitations need to be consider, according to Roger Gassert. Brain-computer interfaces (BCIs) allow people with severe physical or speech disabilities to interact; and communicate with their surroundings using their thoughts interpreted by a computer. Elon Musk’s Neuralink recently presented the company’s plans; for using innovative “threads”ultrathin flexible electrodes that could be implanted in the cerebral cortex; to connect people with the digital world.

Research has already produced impressive results over the past decades: in several studies; finger-sized neural interfaces incorporating a hundred minute electrodes implant in the cerebral cortex of persons with tetraplegia. This interface allowed these people to control a robotic arm to perform reach and grasp movements, by thinking of moving their own; paralyse, limb. In another ground-breaking study, persons in a completely locked-in state able to answer questions with “yes” or “no” responses.

In this case, functional near infrared spectroscopy used as a non-invasive means to measure oxygenation changes in the blood; and the results analysed with the help of a machine learning algorithm. People in the completely locked-in state are unable to move their muscles voluntarily, so they have no other means of expressing themselves.

Brain-computer interfaces technology

However, such spectacular announcements and research stories cannot mask the fact that BCI technology; as a whole is still very much in its infancy. BCIs are very rarely encountered in everyday life, if at all even in people with a severe physical disability. The only application that I am aware of is where persons with severe physical disability operate a spelling device; either as a supplement to their usual device control by eye movements or in cases where full paralysis is causing a completely locked-in state and they are unable to control their eye muscles.

There are many reasons for the limited transfer of BCIs into routine applications. Invasive BCI systems with implanted electrodes, for example, require neurosurgery; carry the risk of infection and the signal quality of the electrodes currently used deteriorates over the months. This type of intervention is therefore only justified in cases of severe chronic disability; and thus far only available in the context of research studies.

Although non-invasive BCI systems are much safer and more common; they also have many weaknesses: their signal quality is much worse than when electrodes implant by surgery, as the distance to the brain is greater. In addition, movements of the forehead, eye or neck muscles can interfere with the signal. Even with well-trained users, BCIs only interpret simple commands correctly in 60 to 90 % of cases. This is insufficient for uses where safety is critical; such as controlling an electric wheelchair.

Neuronal activity patterns

Using EEG-BCI technology to issue commands also requires a relatively high cognitive effort from users, and around a fifth of subjects do not manage to control the brain-computer interface reliably. This is refer to as BCI illiteracy. One also needs to consider the following: BCIs are not capable of “mind reading,” not now nor in the foreseeable future. BCI systems recognise neuronal activity patterns generated by certain thoughts or cognitive tasks. Generating commands by thoughts, however, is not the same as “mind reading.”

It is up to both researchers and the media to clearly highlight not only the possibilities, but also the limitations and ethical consequences of BCIs. In the case of scientific studies on this technology, the methods used need to be better documented, the data sets made publicly available, and the limitations communicated more effectively. At present, BCIs are often still treat like a black box, and even experts sometimes have difficulty interpreting the results of the studies.

In a therapy scenario, for example, wrong decisions and delayed commands do not represent a safety risk, in contrast to a BCI-control wheelchair. Furthermore, BCIs are the only way to recognise motor commands in the brain of these patients. These commands can be sent to a robot or electrical muscle stimulator to move the paralysed limbs and potentially strengthen the biological connection to the brain.