Electrophysiology is a timely and important tool in the study of early cognitive development. This commentary polishes the definition of event-related potential (ERP) components; often interpreted as expressions of mental processes. Further, attention is drawn to time-frequency analysis of the electroencephalogram (EEG) which conveys much more information than the exclusive use of traditional ERP methodology. Several studies have shown that frequency bands of the EEG undergo systematic development in early childhood. EEG frequency analysis has a potential in early risk assessment. 40 Hz gamma range oscillation bursts accompany stimulus feature binding both in infants and in adults, probably indexing grouping and selection of distributed neuronal populations. Methodological concerns are noted and the need for long-term normative studies is stressed. Copyright © 2005 John Wiley & Sons, Ltd.