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 is performed by multiplying the stimulus-locked average by a previously created prototype average; and a memory coupled to the processor and configured to provide the processor with instructions.