Imaging Memory with Event-Related Potentials (ERPs)
Event-related potentials, or ERPs, are the brain’s response to sights and sounds. We record the brain’s activity using sensors or electrodes that rest on the surface of the scalp. The electrodes measure the brain’s activity in response to pictures, such as of the nesting cups and block that we use to “make a rattle.” By comparing how the brain responds to pictures of things that the infant or child has seen before, and how it responds to pictures from sequences that have not been demonstrated, we can “see” the neural processing that takes place as infants and children remember.
Schematic of an ERP Waveform |
Modeling our high-tech headgear! |
Using event-related potentials (ERPs), we have found that dramatic changes in learning take place late in the first year of life. For example, when we show 9-month-old infants pictures from sequences they have seen before and pictures from sequences they have never seen before, they show a larger neural response to “what’s new.” In contrast, 10-month-old infants show a larger neural response to pictures from the sequences they have seen before. We think it is no coincidence that the older infants also have more robust memory for the sequences when we give them the opportunity to reproduce (imitate) them a month later. By studying behavior and brain in the same infants, we gain substantial insight into what is developing, when, and why.