Chapter 3 explores event-related potentials (ERPs), one of electroencephalography’s most powerful analytical techniques for investigating cognitive processing. The chapter traces ERPs’ evolution from Pauline and Hallowell Davis’s pioneering work in 1939 through its exponential growth as a research methodology. It explains how ERPs extract meaningful neural signals by time-locking and averaging EEG segments surrounding stimulus presentations, thereby revealing characteristic voltage deflections that correspond to specific cognitive processes. The text examines key ERP components, including C1, P1, N1, P2, N2, and P300, detailing their temporal progression, neuroanatomical origins, and functional significance in the processing hierarchy. It evaluates ERPs’ exceptional capacity to discriminate between processing stages occurring within milliseconds of each other, from early sensory encoding through attention allocation to semantic processing. The chapter addresses methodological considerations essential for robust ERP research, including experimental design principles, artifact reduction techniques, and the interpretation of scalp topographies. By analyzing ERPs’ comparative advantages, including millisecond-precise temporal resolution, ability to track covert processing without behavioral responses, and sensitivity to processing stage differences, alongside their limitations in spatial localization and specific experimental contexts, the chapter positions ERPs as a vital methodology for understanding the sequential unfolding of perceptual and cognitive processes in the human brain.