Electrophysiologists studying the brain must often choose whether to observe the forest or the trees: electroencephalogram (EEG) and local field potentials (LFP) measure macroscopic oscillations in large populations of neurons, while single unit recordings measure microscopic potentials generated by single cells. I'm interested in the relationship between these two in motor cortex, where high frequency (10- 45Hz) oscillations are commonly observed. These oscillations are clearly modulated by behavior, but some authors have argued that they are a symptom of cortical inactivation in the absence of movement, while others have suggested they serve a role in sensorimotor integration across distributed regions of cortex. It is well known that oscillations affect the timing of action potentials generated by many motor cortical cells, but the significance of this effect - which occurs at the intersection of two levels of analysis - is not well understood. I'm interested in the behavioral relevance of these oscillations and the effect of oscillatory structure on the information encoded and communicated in neuronal spikes. In our lab we record  single units and LFPs from motor and pre-motor cortex using high-density, 100-electrode arrays in behaving animals.