Quantum projections on conceptual subspaces: A deeper dive into methodological challenges and opportunities.

In alignment with the distributional hypothesis of language, the work "Quantum Projections on Conceptual Subspaces" (Martínez-Mingo A, Jorge-Botana G, Martinez-Huertas JÁ, et al. Quantum projections on conceptual subspaces. Cogn Syst Res 2023; 82: 101154) proposed a methodology for generating conceptual subspaces from textual information based on previous work (Martinez-Mingo A, Jorge-Botana G and Olmos R. Quantum approach for similarity evaluation in LSA vector space models. 2020). These subspaces enable the utilization of the quantum model of similarity put forth by Pothos and Busemeyer (Pothos E, Busemeyer J. A quantum probability explanation for violations of symmetry in similarity judgments. In Proceedings of the annual meeting of the cognitive science society, 2011, Vol. 33, No. 33), allowing for the empirical examination of the violations of assumptions concerning symmetry and triangular inequality (Tversky A. Features of similarity. Psychol Rev 1977; 84: 327-352; Yearsley JM, Barque-Duran A, Scerrati E, et al. The triangle inequality constraint in similarity judgments. Prog Biophys Mol Biol 2017; 130: 26-32), as well as the diagnosticity effect (Tversky A. Features of similarity. Psychol Rev 1977; 84: 327-352; Yearsley JM, Pothos EM, Barque-Duran A, et al. Context effects in similarity judgments. J Exp Psychol Gen 2022; 151: 711-717), within a data-driven environment. These psychological biases, deeply studied by authors such as Tversky and Kahneman, inform us about the limitations of modeling psychological similarity measures using tools from classical geometry. This commentary aims to offer methodological clarifications, discuss theoretical and practical implications, and speculate on future directions in this field of research. Concretely, it aims to propose the use of different contours (conceptual or contextual) to generate the subspaces, which lead to subspaces of terms or contexts. Once these contours are defined, a differentiation is proposed between Aggregated Terms Subspaces (ATSs), Aggregated Contexts Subspaces (ACSs), and Aggregated Features Subspaces (AFSs) depending on whether we define the subspaces by grouping the terms or contexts within the contour, or from the latent dimensions of the semantic space obtained in the contour window. Finally, new data is provided on the violation of the triangular inequality assumption through the application of the quantum similarity model to ATSs.

Are valence and arousal related to the development of amodal representations of words? A computational study.

In this study, we analyzed the relationship between the amodal (semantic) development of words and two popular emotional norms (emotional valence and arousal) in English and Spanish languages. To do so, we combined the strengths of semantics from vector space models (vector length, semantic diversity, and word maturity measures), and feature-based models of emotions. First, we generated a common vector space representing the meaning of words at different developmental stages (five and four developmental stages for English and Spanish, respectively) using the Word Maturity methodology to align different vector spaces. Second, we analyzed the amodal development of words through mixed-effects models with crossed random effects for words and variables using a continuous time metric. Third, the emotional norms were included as covariates in the statistical models. We evaluated more than 23,000 words, whose emotional norms were available for more than 10,000 words, in each language separately. Results showed a curve of amodal development with an increasing linear effect and a small quadratic deceleration. A relevant influence on the amodal development of words was found only for emotional valence (not for arousal), suggesting that positive words have an earlier amodal development and a less pronounced semantic change across early lifespan.

Validation of the usefulness of 2-dimensional strain parameters to exclude acute rejection after heart transplantation: a multicenter study.

INTRODUCTION AND OBJECTIVES: Two-dimensional speckle-tracking echocardiography has emerged as a promising alternative to endomyocardial biopsy to rule out acute cellular rejection after orthotopic heart transplantation (OHT) in single center studies. In an original cohort, 15.5% and 17% of cutoff points for left ventricular global longitudinal strain (LVGLS) and free-wall right ventricular longitudinal strain, respectively, achieved 100% negative predictive value to exclude moderate or severe acute cellular rejection (ACR ≥ 2R). Our objective was to demonstrate the usefulness of speckle-tracking and validate these cutoff points in an external cohort. METHODS: A prospective, multicenter study that included patients who were monitored during their first year after OHT was conducted. Echocardiographic studies analyzed by local investigators were compared with simultaneous paired endomyocardial biopsies samples. RESULTS: A total of 501 endomyocardial biopsy-echocardiographic studies were included in 99 patients. ACR≥2R was present in 7.4% of samples. LVGLS and free-wall right ventricular longitudinal strain were significantly reduced during ACR≥2R on univariate analysis. On multivariate analysis, LVGLS was independently associated with the presence of ACR≥2R. The original cutoff points demonstrated a negative predictive value of 94.3% to exclude ACR≥2R. CONCLUSIONS: This study maintained a strong negative predictive value to exclude ACR≥2R after OHT and LVGLS was independently associated with the presence of ACR≥2R. We propose the use of speckle-tracking, especially LVGLS, as part of the noninvasive diagnosis and management of ACR.