# On the Foundations of the Brussels Operational-Realistic Approach to Cognition

arXiv: https://arxiv.org/abs/1512.08710 · HTML: https://mlsanity.com/paper/1512.08710/

## Key facts

- Cited by 5 papers in the map (data through 14 Oct 2026).
- First posted on arXiv 29 Dec 2015.

## Built on by (most cited first, 5 of 5)

- [Are Words the Quanta of Human Language? Extending the Domain of Quantum Cognition](https://mlsanity.com/paper/2110.04913/) (2021)
- [Development of a Thermodynamics of Human Cognition and Human Culture](https://mlsanity.com/paper/2212.12795/) (2022)
- [Entanglement as a Method to Reduce Uncertainty](https://mlsanity.com/paper/2302.05898/) (2023)
- [Identifying Quantum Mechanical Statistics in Italian Corpora](https://mlsanity.com/paper/2412.07919/) (2024)
- [Pretty Good Measurement for Radiomics: A Quantum-Inspired Multi-Class Classifier for Lung Cancer Subtyping and Prostate Cancer Risk Stratification](https://mlsanity.com/paper/2603.00223/) (2026)

## Abstract (arXiv)

The scientific community is becoming more and more interested in the research that applies the mathematical formalism of quantum theory to model human decision-making. In this paper, we provide the theoretical foundations of the quantum approach to cognition that we developed in Brussels. These foundations rest on the results of two decade studies on the axiomatic and operational-realistic approaches to the foundations of quantum physics. The deep analogies between the foundations of physics and cognition lead us to investigate the validity of quantum theory as a general and unitary framework for cognitive processes, and the empirical success of the Hilbert space models derived by such investigation provides a strong theoretical confirmation of this validity. However, two situations in the cognitive realm, 'question order effects' and 'response replicability', indicate that even the Hilbert space framework could be insufficient to reproduce the collected data. This does not mean that the mentioned operational-realistic approach would be incorrect, but simply that a larger class of measurements would be in force in human cognition, so that an extended quantum formalism may be needed to deal with all of them. As we will explain, the recently derived 'extended Bloch representation' of quantum theory (and the associated 'general tension-reduction' model) precisely provides such extended formalism, while remaining within the same unitary interpretative framework.