An exploratory study of factors affecting single trial P300 detection

A threshold detector for single-trial P300 detection has been evaluated. The detector operates on the 0-4 Hz band, isolated from the raw electroencephalogram using low-pass filtering, wavelet transforms, or the piecewise prony method (PPM). A detection rate around 70% was found, irregardless of stimulus type, interstimulus interval (ISI), probability of occurrence (P/sub r/) of the target stimuli, intrasession and intrasession effects, or filtering method. This suggests that P300-based brain-machine interfaces can use an ISI as short as 1 s and a P/sub r/ of 45%, to increase throughput.