Alejandro Wainselboim

We present a novel approach for detecting generalized sleep pathologies through fractal analysis of single-channel EEG signals. We propose that the fractal scaling exponent of permutation entropy time series serves as a robust biomarker of pathological sleep patterns, capturing alterations in brain dynamics across multiple disorders. Using two public datasets (Sleep-EDF and CAP Sleep Database) comprising 200 subjects (112 healthy controls and 88 patients with various sleep pathologies), we computed the fractal scaling of the permutation entropy of these signals. Our results demonstrate significantly reduced scaling exponents in pathological sleep compared to healthy controls (mean = 1.24 vs. 1.06, p<0.001), indicating disrupted long-range temporal correlations in neural activity. The method achieved 90% classification accuracy for REM sleep behavior disorder (F1-score: 0.89) and maintained 74% accuracy when aggregating all pathologies (insomnia, narcolepsy, sleep-disordered breathing, etc.). Key advantages of this approach include compatibility with single-channel EEG (enabling potential wearable applications), independence from sleep-stage annotations, and generalizability across recording montages and sampling rates. This contribution establishes a framework for computationally efficient, non-specific sleep pathology detection that could transform screening protocols and enable earlier intervention.

We present an eyetracking study that investigates how linking is achieved during real-time comprehension of Spanish sentences with causative psych verbs and alternative case marking. This group of verbs lead to verbs’ argument structures that require direct or inverse syntax-to-semantics linking according to the type of case marking assigned to their object. The study aimed at disentangling whether processing inverse linking was more costly than direct linking, and exploring how incremental argument interpretation takes place when lexemes that accept several case markings are used. Results showed that during incremental comprehension, inverse linking is more difficult than direct linking, irrespective of word order. As for argument interpretation, the current study partially replicated the results of previous studies conducted in this language using different verb types. Findings are discussed under the light of different psycholinguistic models addressing case marking processing and incremental linking.

La comprensión de textos depende de habilidades lingüísticas específicas (como el vocabulario y la fluidez de lectura) y procesos cognitivos de dominio general, como las funciones ejecutivas. Si bien existe evidencia de la participación del control inhibitorio en la comprensión en niños de escolaridad primaria, hay aún cierta controversia en cuanto al rol de procesos específicos, como la inhibición perceptual o la supresión de respuestas prepotentes. Por otra parte, los modelos teóricos y la evidencia empírica sugieren que el tipo de procesamiento y la demanda cognitiva sería diferente al comparar textos expositivos y narrativos. El presente estudio se propuso: 1) analizar y comparar la contribución del vocabulario, la eficacia lectora y el control inhibitorio (resistencia a distractores e inhibición de respuesta) a la comprensión de textos expositivos y narrativos, en niños de cuarto grado; 2) examinar la contribución de estas variables al rendimiento académico. Participaron del estudio 57 niños de 9 a 10 años de edad. Se encontraron mayores efectos del vocabulario, la eficacia lectora y la inhibición de respuestas verbales sobre la comprensión de textos expositivos, indicadores de una mayor demanda cognitiva en este género. La facilidad del acceso léxico-semántico y la inhibición perceptual contribuyeron a la comprensión de ambos tipos de texto, siendo este último efecto mediado por la eficacia lectora. Por último, la comprensión del texto expositivo fue la variable más relevante para explicar el rendimiento académico.

It is assumed that semantic transparency in compounds depends on integration of constituents and head transparency. Spanish verb-noun compounds are semantically and morphologically exocentric, lacking a head. We studied if verb argument structure determines differences in semantic integration and morphological decomposition. During a lexical decision task, Agentives (referent takes the role of agent), and Metaphoricals (involving methaphorical patterns to construct meaning), were displayed as whole words or separated into constituents. Agentives were responded better and faster than Metaphoricals, with no interaction between compound type and presentation mode, suggesting constituent decomposition for both compounds. Early electrophysiological effects related to visual recognition, and an N400 component for Metaphoricals, suggest constituent semantic integration. Differences seemed related to combinatorial procedures: in Agentives the meaning of constituents is easily integrated to form compound meaning; in Metaphoricals, this procedure is inhibited, and compound meaning is accessed through the metaphoric relation that links both constituents.

Many computational theories have been developed to improve artificial phonetic classification performance from linguistic auditory streams. However, less attention has been given to psycholinguistic data and neurophysiological features recently found in cortical tissue. We focus on a context in which basic linguistic units–such as phonemes–are extracted and robustly classified by humans and other animals from complex acoustic streams in speech data. We are especially motivated by the fact that 8-month-old human infants can accomplish segmentation of words from fluent audio streams based exclusively on the statistical relationships between neighboring speech sounds without any kind of supervision. In this paper, we introduce a biologically inspired and fully unsupervised neurocomputational approach that incorporates key neurophysiological and anatomical cortical properties, including columnar organization, spontaneous micro-columnar formation, adaptation to contextual activations and Sparse Distributed Representations (SDRs) produced by means of partial N-Methyl-D-aspartic acid (NMDA) depolarization. Its feature abstraction capabilities show promising phonetic invariance and generalization attributes. Our model improves the performance of a Support Vector Machine (SVM) classifier for monosyllabic, disyllabic and trisyllabic word classification tasks in the presence of environmental disturbances such as white noise, reverberation, and pitch and voice variations. Furthermore, our approach emphasizes potential self-organizing cortical principles achieving improvement without any kind of optimization guidance which could minimize hypothetical loss functions by means of–for example–backpropagation. Thus, our computational model outperforms multiresolution spectro-temporal auditory feature representations using only the statistical sequential structure immerse in the phonotactic rules of the input stream.

The following abstract contains 150 words: Studies regarding compound word processing have centred on Noun–noun words, which exhibit endocentricity. Nevertheless, other compound types, such as Spanish Verb–noun compounds, exhibit morphological particularities such as exocentricity, verb argument structure, and metaphorical features, increasing the attributes that may influence compound processing. We analysed whether these traits influenced Spanish Verb–noun compound processing. A lexical decision task was administrated with electroencephalogram (EEG) recording. Following differences in argument structure and metaphorical traits, three compound types were presented: Agentives, Locatives, and Metaphoricals. Locatives were responded worse and slower than Agentives. Metaphoricals elicited increases in the P300 and P600-like components. Thus, verb argument structure and metaphorical processes influence Spanish Verb–noun compound processing. Similarly to endocentric English Noun–noun compounds, processing Spanish Verb–noun compounds involves specific conceptual operations. These conceptual combinations appear to be determined by the projection of verb argument structure and the mapping and assignation of thematic roles.

We report an eye-tracking experiment that examined argument linking and the role of prominence in Spanish sentence comprehension by testing the interplay between word order and verb type. Previous evidence from a self-paced reading study (Gattei, Dickey, Wainselboim, & París, 2015). showed that comprehenders use morphosyntactic information to form predictions about the thematic structure of the upcoming verb. In this study we focussed on the time course of this process. Results showed an interaction between verb type and word order for late eye movement measures but not for early eye movement measures. Participants regressed more and for longer time when word order did not match the canonical order for each verb class. This interaction is observed from the verb region onwards, independently of word order. We interpret that these effects take place due to the misinterpretation of the prominence status of the preverbal argument, leading to differential reading strategies.