1. A system, comprising: a processor configured to: generate a stimulus-locked average signal of a plurality of EEG signal samples; and determine whether the plurality of EEG signal samples are evoked in response to a pattern of stimulus events, wherein: the determination of whether the plurality of EEG signal samples are evoked in response to a pattern of stimulus events includes multiplying the stimulus-locked average by a prototype average that adapts to a user's EEG signals; or the determination of whether the plurality of EEG signal samples are evoked in response to a pattern of stimulus events includes integrating the EEG signal data to generate a result, and comparing the result to a threshold; or the determination of whether the plurality of EEG signal samples are evoked in response to a pattern of stimulus events is performed using a time domain classifier; and a memory coupled to the processor and configured to provide the processor with instructions.