Progress in understanding perceptual systems requires rigorous study of neural mechanisms, both in the periphery and in the brain. CPS laboratories have state-of-the-art facilities for research on the neural mechanisms of perception. These include facilities for extracellular recording, intracellular recording, multi-electrode (tetrode) recording and voltage-sensitive-dye imaging in awake-behaving preparations, as well as in vivo calcium imaging. There is also an active fMRI imaging center with new facilities adjacent to CPS. There are also state-of-the-art facilities for the measurement and stimulalation of neural activity in human perceptual systems (e.g., evoked potentials, transcranial magnetic stimulation, and otoacoustic emissions).