Ken finds that one of the most interesting and least understood functions of the brain is its ability to organize purposeful behaviors to react to the environment, using an enormous amount of information ranging from perception to emotion. To study how the brain accomplishes this, Ken switched to neuroscience after receiving his BS in Physics from the Faculty of Integrated Human Studies, Kyoto University in 1997. Using mathematical techniques, Ken built a theoretical framework for stochastically spiking neurons, which can represent the population dynamics of biological neuronal models, under the supervision of Prof. Shin Ishii at the Theoretical Life Sciences Lab, Nara Institute of Science and Technology.
Many new theoretical approaches emerging in neuroscience today are contributing greatly to our understanding of brain function. To realize the full potential of the theoretical work, close cooperation of theory and experiment is needed. Ken was fortunate to have the opportunity to work directly with experimental researchers in the Lab of Cognitive Neurobiology, Hokkaido University Graduate School of Medicine, where he worked as an instructor after receiving his PhD from NAIST in 2001. In the lab he began to perform his own experiments in physiology under the supervision of Prof. Toshiyuki Sawaguchi. The main theme of his research was the integration of motivation and cognition in the prefrontal cortex. Based on extracellular recordings, the lab found that the reward expectation in the prefrontal cortex selectively enhanced the working memory used for decision of a motor command, suggesting that the prefrontal cortex is mainly involved in guiding a goal-directed behavior.
Following his training and research in neurophysiology, Ken joined the Graybiel Lab in 2005. Ken's present interests include, experimentally, the cooperative functions of the basal-ganglia and prefrontal cortex, and theoretically, statistical inference and neurodynamics. The long-term purpose of his research is to use a combined approach of theory and experiment to determine how the brain links emotion with behavior. An important step toward this goal would be to study the behavioral learning based on neuromodulators, a part of which would be observed as the changes in neuronal activity or oscillation in vivo after a neurochemical operation.