The human brain performs countless cognitive functions, but Professor Fujita’s research focuses especially on vision. How does the brain process information and create "a world inside our head"? Professor Fujita uses cutting-edge technology to explore real-time information processing within the brain.
Coming to terms with complex mechanisms that make “seeing” possible
One of my current interests is the question of why the world appears three-dimensional. The world seen through the right eye only has a slight horizontal discrepancy from the world seen through the left eye only. The discrepancy is considerable in objects close to us, but less for those further away. The brain identifies this difference in degree of discrepancy and converts it to depth perception, a brain function known as binocular stereopsis. One of the major pillars of my research is the study of this stereopsis function.
For many years, it was thought that the information used for stereopsis was transmitted in the brain from the primary visual cortex to the parietal lobe, but our research has revealed that the temporal lobe is also involved. We are now investigating how the roles of the parietal and temporal lobes are divided in order for us to see the world in three dimensions. To date, we have discovered that the division of duties between the two parts occurs in certain situations, such as when objects are moving rapidly, and when there is a need to see them in detail.
Visual research methods without precedent worldwide
Another pillar of my research involves shedding light on the functional architecture of cells in the cerebral cortex, explaining how the cells are arranged based on their properties and functions. Once we understand the functional architecture, we can make inferences about information processing mechanisms.
In the past, this kind of research involved investigating the properties of neural cells one by one. Today, however, we use what is known as two-photon laser microscopy, which allows us to look at how numerous cells within the brain of a living creature respond to different stimuli. It is still only seven or eight years since this method was first applied to animal experimentation.
Looking forward to the day when interdisciplinary research is routine practice
The research undertaken in my lab requires not only expertise in biology, but also the ability to use a variety of photonic equipment. To analyze the data obtained, we draw on methods developed in the fields of mathematics, statistics, and information science. As a partnership between three Graduate Schools—Information Science and Technology, Frontier Biosciences, and Engineering Science—the Humanware Innovation Program (HWIP) offers the ideal conditions to foster a new generation of researchers capable of advancing the innovative activities of the graduate schools’ various research labs.
Previous generations of researchers treated physiology and anatomy as very different disciplines. Around the time that I was a student, however, people started to take it for granted that both of these disciplines should be studied together. As a result, I am perfectly comfortable with the idea of studying function and structure together. I expect that similar convergences will develop through HWIP. It excites me to think that new fields of research, ones that were previously thought impossible, will one day emerge naturally from this three-way interdisciplinary program.