Arduino based configurable LED stimulus design for multi-frequency SSVEP-BCI

Steady state visually evoked potentials (SSVEP) are extensively used in the research of brain-computer interface (BCI) and require a configurable light source flashing at different frequencies. Precise control of simultaneous multiple frequencies are essential for SSVEP studies and also for reducing the visual fatigue. Instead of LCD based stimulus which requires more resources and power, light emitting diodes (LEDs) are used as a light source as they are energy efficient, consume lower power, have higher contrast, less tiring visually, have multi-chromatic function and supports wider frequency ranges. In this paper, we propose a visual stimulator using off-shelf components to build a simple and yet customisable LED stimulus for testing the performance and qualitative user comfort using SSVEP electroencephalogram (EEG) data.