The brain is composed of billions of interconnected cells, creating the most complex system within the body. To study how such combined neuronal activity underlies an animal’s processing of information, we record signal simultaneously from a large number of neurons using a novel technique: multi-site silicon microelectrodes. Such parallel recordings from groups of neurons in the cortex and in subcortical structures are helping to understand information processing and memory formation in the brain. Our lab also investigates how relations between neuronal populations are distorted by stroke and by different neurological disorders like multiple sclerosis and epilepsy. In pursuit of those research goals, we combine experiments with development of sophisticated data analysis methods and computer models.