BACKGROUND: Event-related potential studies in schizophrenia have demonstrated amplitude reduction of the P3 in oddball tasks. The P3 has been linked to attention and memory brain functions. METHODS: In 24 schizophrenia patients and 28 control subjects, wavelet transform was used to reveal event-related modulations of the EEG signal during target trials in delta, theta, alpha, beta, and gamma frequency bands. RESULTS: Patients showed reductions in P3 amplitude accompanied by reduced low frequency delta-theta and increased beta-gamma band EEG activity. CONCLUSIONS: These results indicate abnormalities in the synchronization and/or efficiency of neural processes involved in memory and attention networks in schizophrenia.