A high rate online SSVEP based brain-computer interface speller

This paper presents an online steady-state visual evoked potential (SSVEP) based brain-computer interface (BCI). Stimuli are displayed on a liquid crystal display (LCD) screen with a frame based encoding method to elicit SSVEPs with a wide range of frequencies. This system focuses strongly on practicability and convenience, including an adequate alphabet (42 characters) that can allow a wide range of options. Four healthy subjects attain a mean information transfer rate (ITR) of 61.64±3.61 bits/min.