My current research topic is "universal design in language use," with special reference to order in language and thought. In particular, I am investigating (1) similarities and differences in neural processing of languages with different basic word orders, (2) to what extent the order in non-verbal thought is affected by the order in language, and vice versa, and (3) what is the optimal order in human language and human thought, if any.

Many studies have reported that subject-object (SO) word order, where the subject (S) precedes the object (O), tends to have lower processing costs and is preferred by native speakers compared to object-subject (OS) word order. However, traditional studies have primarily focused on SO languages, such as Japanese and English, where SO word order is the grammatical default. As a result, it remains unclear whether the preference for SO word order reflects the basic word order of individual languages or more universal cognitive characteristics of humans.

• To address this, we are conducting research on the cognitive processing of minority languages that use object-subject (OS) word order as their basic word order—specifically Kaqchikel and Truku, which have not been studied before. This research focuses on the relationship between “word order in language” and “order of thought.” The findings are then compared to the cognitive processing of Japanese and English.
• For this purpose, experimental equipment is brought to the speakers’ regions (Guatemala and Taiwan) to conduct a variety of investigations and experiments, including behavioral experiments, eye-tracking, and brain function measurements. Additionally, for experiments requiring large, non-portable equipment such as MRI scanners, the speakers are invited to Japan for the studies.

Although I am conducting basic research, I believe it helps develop (1) effective language teaching/learning methods, (2) rehabilitation programs for aphasia, (3) dynamic preservation of endangered languages/dialects, and so on.

• I investigate on the economics of aging, the optimal social welfare policy, low fertility and so on not based on the historical and systematic approach but based on the neo-classical economic theory. I also use econometric method and statistical approach. I often estimate the future projections of the population, public finance, magnitude of private markets, the results of public policies.
• I also research on the comparative studies on East Asia (Japan, China, Korea, Taiwan) and European (especially Scandinavian countries). I provide statistic data and information on the economic and political systems on the aging in Japan.

The future estimation on the financial status , market caused by low fertility and aging. The effective management of the medical institutions, social welfare systems, gender equality societies for the central and local government, research institutions, public enterprises, and financial Institutions.