Brain-computer interface (BCI) is a communication link between a human's brain and an external device.

BCI applications range from lost motor functions replacement to mind-controlled computer games. BCI can also be used not only for generating discrete commands but also for evaluating the mental state of a person such as focus, relaxation or tiredness. In addition, BCI systems are being developed that could essentially be used as lie detectors, which that would be even more difficult to deceive.

Recent research even shows the feasibility of recovering the ‘inner voice‘ of a person from EEG measurements, essentially providing an ability to read a person’s thoughts.

The main components of BCI are reading brain activity and translating that activity to commands understandable by computers or other devices.

There are many methods for measuring brain activity. Each method differs in its invasiveness, time and spatial resolutions. Commonly used techniques to record brain activity are illustrated in the picture below.

From left to right temporal resolution decreases, from <1ms for single-cell and multielectrode array (MEA recordings to around 1s for functional MRI (fMRI).

The colors indicate the approximate physical scale of the activity that can be recorded with each method and the depth limits of the measurements.

Other activity measurement techniques also exist such as magnetoencephalography (MEG), functional near-infrared spectroscopy (fNIRS) and other.

Technology - BrainAccess®
Picture from The University of Queensland Queensland Brain Institute
Technology - BrainAccess®
EEG measures electrical activity of a brain by placing electrodes on a human's scalp
Technology - BrainAccess®

Neurotechnology concentrates on using electroencephalography (EEG) as a way to monitor brain activity for the development of BCI

EEG measures the electrical activity of a brain by placing electrodes on a human's scalp. Traditionally, EEG measurements require scalp preparation and the application of conductive gel for better electrode contact. However, the so-called dry-contact electrodes that do not require any gel are becoming more popular, which makes BCI more applicable outside laboratory environments.

Neurotechnology offers innovative dry-contact EEG electrodes that conform to the shape of the head making them more comfortable to wear than traditional dry-contact electrodes. BrainAccess EEG acquisition hardware is also tailored for the use of dry-contact electrodes as these electrodes typically have larger impedances than gel-based electrodes and care must be taken to ensure good quality recordings.

All the BrainAccess hardware comes with free software, which is provided in a form of software development kit (SDK) giving users the freedom to integrate BrainAccess software into their experiments, applications or products. Multiple programming languages are supported to ease the integration process.