ERP stands for Event-Related Potential. Your brain generates electrical potentials as it works. By placing tiny sensors near the scalp, we can record changes in this potential in response to events in the world. In our studies, we show infants pictures or play sounds for them. They wear a small cap with sensors sewn into it so that we can observe how their brain responds to different stimuli. In this way, we are able to learn about what parts of the infant brain are involved in processing number.