Skip to content

Hayato Saigo

14 papers in the library · 12 citations · publishing 2016-2026

Papers

Sort Most recent Most cited

Measuring the Diversity of Qualia: Category-Theoretic Indices for Psychophysical Experimental Data

F1000Research June 25, 2026 Kyoko Kusano, Hayato Saigo, Naotsugu Tsuchiya

Abstract* Characterizing qualitative aspects of subjective experiences, qualia, remains a challenging open problem. The recent Qualia structure paradigm proposes capturing qualia through massive relations with other qualia. A concrete method for this involves measuring pairwise similarities. This approach has been successfully applied to reveal similarities and differences in qualia structures...

DOI: 10.12688/f1000research.179638.1 (opens in new tab) Qualia Pairwise comparison Diversity politics Experimental data +7

Quantum-like Qualia hypothesis: from quantum cognition to quantum perception.

Frontiers in Psychology 2024 Naotsugu Tsuchiya, Peter Bruza, Makiko Yamada et al. 8 citations

To arbitrate theories of consciousness, scientists need to understand mathematical structures of quality of consciousness, or qualia. The dominant view regards qualia as points in a dimensional space. This view implicitly assumes that qualia can be measured without any effect on them. This contrasts with intuitions and empirical findings to show that by means of internal attention qualia can...

Qualia Structure Proposal (Japanese version)

July 15, 2023 Naotsugu Tsuchiya, Hayato Saigo, Steven Phillips et al. preprint

主観意識と客観的な物質としての脳は、全く異なる世界に属すのだろうか? 意識の中身であるクオリアと脳はいかに関係しているのか? 意識と脳の問題は、科学的な興味に留まらず、現実社会における人の気持ちの理解の困難に伴う問題にも直接関わる。意識のクオリアは、客観的な言語で定義することすら難しいため、従来の意識研究では、知覚刺激を固定し、経験を「見えた・見えない」という二値的な判断に還元し、その神経相関の探求を試みた。近年、我々は視覚クオリア間の類似度を大規模に計測することでクオリアの構造を特徴づけ、その神経相関とその情報構造を明らかにする新パラダイムを確立した。本領域は、現象学・発達・構成論を加え、知覚と感情クオリアに集中することで、クオリア構造学を創成する。本領域の成果は、他者意識の理解や、動物や人工物の意識理解など、一般社会へも広く還元されうる答えを生み出す新融合領域の創成である。

Qualia Structure Proposal (English version)

July 15, 2023 Naotsugu Tsuchiya, Hayato Saigo, Steven Phillips et al. preprint

Summary: Establishing Qualia Structure Paradigm.?Do subjective conscious experience and objective brain matters belong to completely different worlds? How are qualia, the contents of consciousness, related to the brain? The question of consciousness and the brain is not only of scientific interest, but it is also directly related to the problems associated with difficulties in understanding...

Quantum-like Qualia hypothesis: from Quantum Cognition to Quantum Perception

PsyArXiv June 2, 2023 Naotsugu Tsuchiya, Peter Bruza, Makiko Yamada et al. preprint

To arbitrate theories of consciousness, scientists need to understand mathematical structures of quality of consciousness, or qualia. The dominant view regards qualia as points in a dimensional space. This view implicitly assumes that qualia can be measured without any effects on it. This contrasts with intuitions and empirical findings to show that by means of internal attention qualia can...

The monoid-now: a category theoretic approach to the structure of phenomenological time-consciousness.

Frontiers in Psychology 2023 Shigeru Taguchi, Hayato Saigo 4 citations

Human consciousness is characterized by constant transitions in time. On the other hand, what is consciously experienced always possesses the temporal feature of "now." In consciousness, "now" constantly holds different contents, yet it remains "now" no matter how far it goes. This duality is thematized in Husserlian phenomenology as "the standing-streaming now." Although this phrase appears...

Enriched category as a model of qualia structure based on similarity judgements.

Consciousness and Cognition May 1, 2022 Naotsugu Tsuchiya, Steven Phillips, Hayato Saigo

Qualitative relationships between two instances of conscious experiences can be quantified through the perceived similarity. Previously, we proposed that by defining similarity relationships as arrows and conscious experiences as objects, we can define a category of qualia in the context of category theory. However, the example qualia categories we proposed were highly idealized and limited to...

An adjunction hypothesis between qualia and reports.

Frontiers in Psychology 2022 Naotsugu Tsuchiya, Hayato Saigo, Steven Phillips

What are the nature of the relationship among qualia, contents of consciousness, and behavioral reports? Traditionally, this type of question has been only addressed via a qualitative and philosophical approach. Some theorists emphasize an incomplete and inaccurate nature of reports of one's own qualia to discourage formal research programs on qualia. Other empirical researchers, however, have...

DOI: 10.3389/fpsyg.2022.1053977 (opens in new tab) Full text (opens in new tab) Adjunction Category theory Consciousness Qualia +1

A relational approach to consciousness: categories of level and contents of consciousness

Neuroscience of Consciousness October 1, 2021 Naotsugu Tsuchiya, Hayato Saigo

Abstract Characterizing consciousness in and of itself is notoriously difficult. Here, we propose an alternative approach to characterize, and eventually define, consciousness through exhaustive descriptions of consciousness’ relationships to all other consciousness. This approach is founded in category theory. Indeed, category theory can prove that two objects A and B in a category can be...

Mathematics and the Brain: A Category Theoretical Approach to Go Beyond the Neural Correlates of Consciousness

Entropy December 1, 2019 Georg Northoff, Naotsugu Tsuchiya, Hayato Saigo

Consciousness is a central issue in neuroscience, however, we still lack a formal framework that can address the nature of the relationship between consciousness and its physical substrates. In this review, we provide a novel mathematical framework of category theory (CT), in which we can define and study the sameness between different domains of phenomena such as consciousness and its neural...

Using category theory to assess the relationship between consciousness and integrated information theory.

Neurosciences research June 1, 2016 Naotsugu Tsuchiya, Shigeru Taguchi, Hayato Saigo

One of the most mysterious phenomena in science is the nature of conscious experience. Due to its subjective nature, a reductionist approach is having a hard time in addressing some fundamental questions about consciousness. These questions are squarely and quantitatively tackled by a recently developed theoretical framework, called integrated information theory (IIT) of consciousness. In...

Applying Yoneda's lemma to consciousness research: categories of level and contents of consciousness

Naotsugu Tsuchiya, Hayato Saigo preprint

Characterizing consciousness in and of itself is notoriously difficult. Any effort to define consciousness seems to evade what it tries to achieve. In particular, definitions often involve comparisons of different kinds of “consciousness” in a self-referential manner. The tautological nature of characterizing consciousness has led some scholars to propose that establishing a science of...

What does it mean to enrich the definition of consciousness in consciousness research using (enriched) category theory?

Naotsugu Tsuchiya, Hayato Saigo preprint

In our recent essay on Cognitive Science [Naotsugu Tsuchiya & Hayato Saigo (2019) “Understanding Consciousness Through Category Theory” vol 26, pp 462 - 477], we provided a general introduction of category theory to consciousness researchers. Further, we also provided our tentative theoretical sketches on our latest ideas on how to apply tools in category theory into consciousness research. In...