Is There P300 Asymmetry in Schizophrenia?

To the Editor.—  We wish to add an important update with respect to the review of our laboratory's work on the auditory P300 event-related potential in schizophrenia that was presented in the recent carefully prepared report of Pfefferbaum et al.¹ This work affirmed the importance of the P300 in schizophrenia research but failed to confirm our repeated finding of a lateralized left<right temporal scalp voltage asymmetry (P300 asymmetry) and suggested potential factors and confounders in our work that might be responsible for their failure to replicate. New data arising from our laboratory since the submission of the report by Pfefferbaum et al make many of their explanations for the replication failure highly unlikely.We have found the P300 asymmetry in schizophrenics using only the waveform associated with the target stimulus,² the waveform used by Pfefferbaum et al.¹ Our previous studies used a waveform subtraction paradigm.³Our