Towards User-Friendly Spelling with an Auditory Brain-Computer Interface: The CharStreamer Paradigm
The typical oddball scenario with the classification of random stimulation sequences is depicted in plot A and B. For sequential stimuli, it can be observed that classifier outputs of non-targets before or after a target behave similar to target responses (plot C). This leads to systematic structural distortions in the standard multi-class decision (D). Plot E depicts how a meta classifier can make explicit use of the sequential information and thereby improve the multi-class decision.