An Attempt of Speed-up of Neurocommunicator, an EEG-Based Communication Aid.

We have been developing the "Neurocommunicator", an EEG-based communication aid for people with severe motor disabilities. This system analyzes an event-related potential (ERP) to the sequentially flashed pictograms to indicate a desired message, and predicts the user's choice in the brain. To speed-up of this decoding process, we introduced a special algorithm, the Virtual Decision Function (VDF), which was originally designed to reflect the continuous progress of binary decisions on a single trial basis of neuronal activities in the primate brain. We applied the VDF to the EEG signals, and succeeded in faster decoding of the target.