The aim of our research is to understand how our perception and behavior are regulated by signals in individual neurons, local networks, and the brain systems. To this end, we conduct single neuron recordings, local pharmacological applications, and electrical stimulation in behaving monkeys, psychophysical assessment of humans, as wells as computational analyses of models that are based on biological observations. In particular, we are interested in voluntary control of eye movements and related brain functions. Eye movements exhibit properties such as sensorimotor transformation, movement decision, learning, and memory that can be generalized to other systems. On the other hand, their reproducibility allows us to perform extensive quantitative analyses and modeling. By taking advantage of this system, we explore the functions of higher brain areas such as the cerebral cortex, basal ganglia, cerebellum and thalamus. Our ongoing projects include neural mechanisms for time perception, rule-based response selection, spatial attention and working memory.