Core B Project Summary The development of reliable, valid and innovative measures of the functioning of the mirror neuron system (MNS), particularly for use with human infants and children is a critical task in order to understand the plasticity and development of this system and its influence on the emergence of social cognition. Core B's aims have been to develop methods for the acquisition and processing of EEG that could identify EEG Event Related Desychronization (ERD) in different age populations and to support the use of these methods in both human and non-human populations across the different projects for assessment of the MNS. These aims were achieved over the past five years. Methods for the acquisition, processing, and analysis of brain electrical activity in human and non-human primates were developed and form the basis for the ability of investigators in in all four projects in the current proposal to be able to acquire, process, and analyze EEG during different tasks and with different age populations. The goals for Core B in the current proposal are to first, build on the achievements of Core B over the past years, with continued support for fidelity of EEG acquisition, processing and analysis of data in the projects; second, develop methods for modeling brain activity acquired with fMRI and EEG to enhance source localization; third, engage in the development of novel and innovative methods for the analysis of EEG network activity and fMRI functional connectivity during tasks involving action execution and observation; and fourth, provide statistical support to the projects in the core. Innovative methods for both source localization and brain network connectivity will be made available to members of the Program Project and ultimately disseminated to the scientific community.