Roberto Hornero

Roberto Hornero
Universidad de Valladolid | UVA · Department of Theory of Signal and Communications and Telematic Engineering

PhD. Prof.

About

447
Publications
59,430
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8,919
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Additional affiliations
January 2004 - present
Universidad de Valladolid
Position
  • Professor (Full)

Publications

Publications (447)
Article
Full-text available
Background The diagnosis of migraine is mainly clinical and self-reported, which makes additional examinations unnecessary in most cases. Migraine can be subtyped into chronic (CM) and episodic (EM). Despite the very high prevalence of migraine, there are no evidence-based guidelines for differentiating between these subtypes other than the number...
Conference Paper
Previous studies have suggested that the typical slow oscillations (SO) characteristics during sleep could be modified in the presence of pediatric obstructive sleep apnea (OSA). Here, we evaluate whether these modifications are significant and if they may reflect cognitive deficits. We recorded the overnight electroencephalogram (EEG) of 294 pedia...
Article
The gold standard approach to diagnose obstructive sleep apnea (OSA) in children is overnight in-lab polysomnography (PSG), which is labor-intensive for clinicians and onerous to healthcare systems and families. Simplification of PSG should enhance availability and comfort, and reduce complexity and waitlists. Airflow (AF) and oximetry (SpO2) signa...
Article
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In this study, we present a new Deep Learning (DL) architecture for Motor Imagery (MI) based Brain Computer Interfaces (BCIs) called EEGSym. Our implementation aims to improve previous state-of-the-art performances on MI classification by overcoming inter-subject variability and reducing BCI inefficiency, which has been estimated to affect 10-50% o...
Article
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Despite significant and meritorious research efforts over the last decades, the functions and evolutionary determinants of sleep remain one of the mysterious and relatively unexplored dimensions of physiology (Krueger et al, 2016). The recipe for deciphering such an attractive challenge in biology and medicine most probably includes ingredients suc...
Article
Hallucinations are considered characteristic symptoms of psychosis and part of the ‘psychosis superspectrum’ of the Hierarchical Taxonomy Of Psychopathology (HiTOP) initiative. To gain insight into their psychopathological relevance, we studied their dimensional placement within a single dense transdiagnostic network constituting of basic symptoms...
Article
Objective: Schizophrenia is a psychiatric disorder that has been shown to disturb the dynamic top-down processing of sensory information. Various imaging techniques have revealed abnormalities in brain activity associated with this disorder, both locally and between cerebral regions. However, there is increasing interest in investigating dynamic n...
Article
Background and objective: Brain-computer interfaces (BCI) based on event-related potentials (ERP) are a promising technology for alternative and augmented communication in an assistive context. However, most approaches to date are synchronous, requiring the intervention of a supervisor when the user wishes to turn his attention away from the BCI s...
Chapter
Motor and cognitive disabilities may lead to communication difficulties, exacerbated by the intelligibility of speech and gesture. In this context, brain–computer interfaces (BCIs) can be viewed as novel augmentative and alternative communication technologies to assist these people. Despite the extensive research in BCIs during the last decades, po...
Chapter
Neurofeedback training (NFT) allows to self-regulate neural activity, having application on a wide range of disorders to improve cognitive functions. This work was aimed at designing, developing and testing a novel NFT platform to prevent cognitive decline due to normal ageing in elderly population. A closed-loop brain-computer interface based on e...
Conference Paper
Full-text available
Resumen La enfermedad de Alzheimer (EA) es una enfermedad de-generativa con alta prevalencia en la sociedad actual. El diagnóstico de la misma es complejo y costoso. Por ello, se investiga en nuevas formas de caracterización de las altera-ciones que esta enfermedad provoca en la red neuronal. En el presente trabajo se pretende evaluar la robustez d...
Article
Many brain–computer interface (BCI) studies overlook the channel optimization due to its inherent complexity. However, a careful channel selection increases the performance and users’ comfort while reducing the cost of the system. Evolutionary meta-heuristics, which have demonstrated their usefulness in solving complex problems, have not been fully...
Conference Paper
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La enfermedad de Alzheimer (EA) constituye la principal causa de demencia en los países occidentales. Para su estudio se pueden utilizar diversas técnicas neurofisiológicas y de neuroimagen, entre las que destaca la electroencefalografía (EEG) por su bajo coste, portabilidad y ser no invasivo. La EEG ha revelado diferentes alteraciones que provoca...
Article
Full-text available
Neurofeedback training (NFT) has shown promising results in recent years as a tool to address the effects of age-related cognitive decline in the elderly. Since previous studies have linked reduced complexity of electroencephalography (EEG) signal to the process of cognitive decline, we propose the use of non-linear methods to characterise changes...
Article
Objective. Code-modulated visual evoked potentials (c-VEP) have been consolidated in recent years as robust control signals capable of providing non-invasive brain–computer interfaces (BCIs) for reliable, high-speed communication. Their usefulness for communication and control purposes has been reflected in an exponential increase of related articl...
Article
Full-text available
Pediatric obstructive sleep apnea (OSA) is a prevalent disorder that disrupts sleep and is associated with neurocognitive and behavioral negative consequences, potentially hampering the development of children for years. However, its relationships with sleep electroencephalogram (EEG) have been scarcely investigated. Here, our main objective was to...
Article
Overnight pulse oximetry has shown usefulness to simplify obstructive sleep apnea (OSA) diagnosis when combined with machine-learning approaches. However, the development and evaluation of a single model with ability to reach high diagnostic performance in both community-based non-referral and clinical referral cohorts are still pending. Since ense...
Conference Paper
Sleep staging is of paramount importance in children with suspicion of pediatric obstructive sleep apnea (OSA). Complexity, cost, and intrusiveness of overnight polysomnography (PSG), the gold standard, have led to the search for alternative tests. In this sense, the photoplethysmography signal (PPG) carries useful information about the autonomous...
Conference Paper
The main objective of this study was to examine the influence that recording length, sampling frequency, and imaging modality have on the estimation and characterization of spontaneous brain meta-states during rest. To this end, a recently developed method of meta-state extraction and characterization was applied to a subset of 16 healthy elderly s...
Conference Paper
Full-text available
Connectivity analyses are widely used to assess the interaction brain networks. This type of analyses is usually conducted considering the well-known classical frequency bands: delta, theta, alpha, beta, and gamma. However, this parcellation of the frequency content can bias the analyses, since it does not consider the between-subject variability o...
Article
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PICALM and CLU genes have been linked to alterations in brain biochemical processes that may have an impact on Alzheimer’s disease (AD) development and neurophysiological dynamics. The aim of this study is to analyze the relationship between the electroencephalographic (EEG) activity and the PICALM and CLU alleles described as conferring risk or pr...
Article
Study Objectives Pediatric obstructive sleep apnea (OSA) affects cardiac autonomic regulation, altering heart rate variability (HRV). Although changes in classical HRV parameters occur after OSA treatment, they have not been evaluated as reporters of OSA resolution. Specific frequency bands (named BW1, BW2 and BWRes) have been recently identified i...
Article
Full-text available
Pediatric obstructive sleep apnea (OSA) is a breathing disorder that alters heart rate variability (HRV) dynamics during sleep. HRV in children is commonly assessed through conventional spectral analysis. However, bispectral analysis provides both linearity and stationarity information and has not been applied to the assessment of HRV in pediatric...
Article
Full-text available
Dementia due to Alzheimer’s disease (AD) is a neurological syndrome which has an increasing impact on society, provoking behavioral, cognitive, and functional impairments. AD lacks an effective pharmacological intervention; thereby, non-pharmacological treatments (NPTs) play an important role, as they have been proven to ameliorate AD symptoms. Nev...
Conference Paper
Las interfaces cerebro-ordenador (BCI) basadas en potenciales evocados visuales modulados mediante código (c-VEP) están marcando un antes y un después este ámbito. Los comandos a seleccionar se iluminan de acuerdo a una secuencia pseudo-aleatoria desfasada con distintos retardos. Como las iluminaciones de los comandos adyacentes también son percibi...
Article
Full-text available
Alzheimer’s disease (AD) is a neurodegenerative disorder which has become an outstanding social problem. The main objective of this study was to evaluate the alterations that dementia due to AD elicits in the distribution of functional network weights. Functional connectivity networks were obtained using the orthogonalized Amplitude Envelope Correl...
Article
Background Machine‐learning approaches have enabled promising results in efforts to simplify the diagnosis of pediatric obstructive sleep apnea (OSA). A comprehensive review and analysis of such studies increase the confidence level of practitioners and healthcare providers in the implementation of these methodologies in clinical practice. Objecti...
Article
Objective: Nested into slow oscillations (SO) and modulated by their up-states, spindles are electrophysiological hallmarks of N2 sleep stage that present a complex hierarchical architecture. However, most studies have only described spindles in basic statistical terms, which were limited to the spindle itself without analyzing the characteristics...
Article
Full-text available
This study focused on the automatic analysis of the airflow signal (AF) to aid in the diagnosis of pediatric obstructive sleep apnea (OSA). Thus, our aims were: (i) to characterize the overnight AF characteristics using discrete wavelet transform (DWT) approach, (ii) to evaluate its diagnostic utility, and (iii) to assess its complementarity with t...
Article
Pediatric Obstructive Sleep Apnea (OSA) is a respiratory disease whose diagnosis is performed through overnight polysomnography (PSG). Since it is a complex, time-consuming, expensive, and labor-intensive test, simpler alternatives are being intensively sought. In this study, bispectral analysis of overnight airflow (AF) signal is proposed as a pot...
Article
Full-text available
The characterization of the distinct dynamic functional connectivity (dFC) patterns that activate in the brain during rest can help to understand the underlying time-varying network organization. The presence and behavior of these patterns (known as meta-states) have been widely studied by means of functional magnetic resonance imaging (fMRI). Howe...
Article
Full-text available
Full-term pregnancy at an early age confers long-term protection against breast cancer. Published data shows a specific transcriptomic profile controlling chromatin remodeling that could play a relevant role in the pregnancy-induced protection. This process of chromatin remodeling, induced by the breast differentiation caused by the first full-term...
Article
Full-text available
Background: Dementia due to Alzheimer's disease (AD) is a complex neurodegenerative disorder, which much of heritability remains unexplained. At the clinical level, one of the most common physiological alterations is the slowing of oscillatory brain activity, measurable by electroencephalography (EEG). Relative power (RP) at the conventional frequ...
Article
This study aims at assessing the usefulness of deep learning to enhance the diagnostic ability of oximetry in the context of automated detection of pediatric obstructive sleep apnea (OSA). A total of 3196 blood oxygen saturation (SpO2) signals from children were used for this purpose. A convolutional neural network (CNN) architecture was trained us...
Article
Objective: The aim of this study was to solve one of the current limitations for the characterization of the brain network in the Alzheimer's disease (AD) continuum. Nowadays, frequency-dependent approaches have reached contradictory results depending on the frequency band under study, tangling the possible clinical interpretations. Approach: To...
Article
Full-text available
In recent years, deep-learning models gained attention for electroencephalography (EEG) classification tasks due to their excellent performance and ability to extract complex features from raw data. In particular, convolutional neural networks (CNN) showed adequate results in brain-computer interfaces (BCI) based on different control signals, inclu...
Article
Full-text available
The primary genetic risk factor for late onset Alzheimer’s disease (LOAD) is the APOE4 allele of Apolipoprotein E (APOE) gene. The three most common variants of APOE are determined by single nucleotide polymorphisms (SNPs) rs429358 and rs7412. Our aim was to estimate allele and genotype frequencies of APOE variants in an Iberian cohort, thus helpin...
Article
Full-text available
Positional obstructive sleep apnea (POSA) is a major phenotype of sleep apnea. Supine-predominant positional patients are frequently characterized by milder symptoms and less comorbidity due to a lower age, body mass index, and overall apnea-hypopnea index. However, the bradycardia-tachycardia pattern during apneic events is known to be more severe...
Article
Introducción y objetivos: La hipoacusia supone un severo hándicap para cualquier profesional cuya actividad se base en el reconocimiento de sonidos. En el caso de profesionales sanitarios, la auscultación constituye una actividad rutinaria y el padecimiento de hipoacusia la limita en grado variable en función de la severidad de la misma. Aquellos p...
Conference Paper
Full-text available
En este estudio se evalúa la utilidad de una arquitectura deep learning basada en módulos Inception para mejorar la capacidad diagnóstica de la señal de saturación de oxígeno en sangre (SpO2) en la ayuda al diagnóstico de la apnea obstructiva del sueño (AOS) infantil. Estudios recientes demandan la aplicación de nuevas arquitecturas de deep learnin...
Conference Paper
Full-text available
Este estudio se centra en el análisis automático de la señal de flujo aéreo monocanal (FA) para la ayuda en el diagnóstico de la Apnea Obstructiva del Sueño (AOS) infantil. En concreto, se ha evaluado la utilidad diagnóstica de las medidas extraídas de los diferentes niveles de descomposición obtenidos al aplicar la transformada wavelet discreta a...
Conference Paper
Full-text available
El objetivo de este estudio fue evaluar la utilidad de la transformada wavelet de las señales de flujo aéreo (FA) y saturación de oxígeno en sangre (SpO2) para detectar la apnea obstructiva del sueño (AOS) infantil. Para ello, se emplearon las señales de 974 sujetos pediátricos con sospecha de padecer AOS, que se dividieron aleatoriamente en conjun...
Conference Paper
Full-text available
La demencia debida a enfermedad de Alzheimer (EA) es el tipo de demencia más habitual en los países occidentales. Caracterizar la red neuronal desde puntos de vista novedosos puede ser de gran interés para conocer las dinámicas subyacentes a la progresión de esta enfermedad. En este estudio, se pretende evaluar la robustez de la red neuronal constr...
Conference Paper
Full-text available
Dos de los métodos más utilizados para estudiar la actividad electroencefalográfica (EEG) consisten en estimar la densidad espectral de potencia (PSD) para cuantificar los patrones de activación local y en realizar un análisis de red que resuma los patrones de sincronización entre diferentes regiones cerebrales. Ambas aproximaciones se han empleado...
Article
Full-text available
Brain waves, measured by electroencephalography (EEG), are a powerful tool in the investigation of neurophysiological traits and a noninvasive and cost-effective alternative in the diagnostic of some neurological diseases. In order to identify novel Quantitative Trait Loci (QTLs) for brain wave relative power (RP), we collected resting state EEG da...
Article
Full-text available
Diabetic retinopathy (DR) is characterized by the presence of red lesions (RLs), such as microaneurysms and hemorrhages, and bright lesions, such as exudates (EXs). Early DR diagnosis is paramount to prevent serious sight damage. Computer-assisted diagnostic systems are based on the detection of those lesions through the analysis of fundus images....
Conference Paper
Full-text available
La enfermedad de Alzheimer (EA) es el tipo de demencia más común y con mayor impacto en los países occidentales. Esta patología presenta diversos factores que condicionan su evolución, como son la edad, el sexo o la genética. Con el objetivo de explorar las complejas relaciones entre los diversos factores que inciden en la progresión de la EA, se h...
Conference Paper
Motor and cognitive disabilities may lead to communication difficulties, exacerbated by the intelligibility of speech and gesture. In this context, brain-computer interfaces (BCIs) can be viewed as novel augmentative and alternative communication technologies to assist these people. Despite the extensive research in BCIs during the last decades, po...
Article
Background: Classic spectral analysis of heart rate variability (HRV) in pediatric sleep apnea-hypopnea syndrome (SAHS) traditionally evaluates the very low frequency (VLF: 0-0.04 Hz), low frequency (LF: 0.04-0.15 Hz), and high frequency (HF: 0.15- 0.40 Hz) bands. However, specific SAHS-related frequency bands have not been explored. Methods: 1,738...
Article
Full-text available
Objective: Although magnetoencephalography and electroencephalography (M/EEG) signals at sensor level are robust and reliable, they suffer from different degrees of distortion due to changes in brain tissue conductivities, known as field spread and volume conduction effects. To estimate original neural generators from M/EEG activity acquired at se...
Article
Full-text available
The aim of this study was to characterize the EEG alterations in inter-band interactions along the Alzheimer's disease (AD) continuum. For this purpose, EEG background activity from 51 healthy control subjects, 51 mild cognitive impairment patients, 50 mild AD patients, 50 moderate AD patients, and 50 severe AD patients was analyzed by means of bis...
Article
Full-text available
Alzheimer’s disease (AD) is the most prevalent cause of dementia, being considered a major health problem, especially in developed countries. Late-onset AD is the most common form of the disease, with symptoms appearing after 65 years old. Genetic determinants of AD risk are vastly unknown, though, ε 4 allele of the ApoE gene has been reported as t...
Article
Full-text available
Introducción. El aislamiento impuesto durante la pandemia de COVID-19 podría influir en la adherencia a las terapias, especialmente en enfermos crónicos. El objetivo del estudio consistió en analizar el grado de cumplimiento de pacientes con síndrome de apnea obstructiva del sueño (SAOS) en tratamiento domiciliario con presión positiva continua (CP...
Conference Paper
In this study, we use the overnight blood oxygen saturation (SpO2) signal along with convolutional neural networks (CNN) for the automatic estimation of pediatric sleep apnea-hypopnea syndrome (SAHS) severity. The few preceding studies have focused on the application of conventional feature extraction methods to obtain information from the SpO2 sig...
Conference Paper
This study had two main objectives: (i) to study the effects of volume conduction on different connectivity metrics (Amplitude Envelope Correlation AEC, Phase Lag Index PLI, and Magnitude Squared Coherence MSCOH), comparing the coupling patterns at electrode- and sensor-level; and (ii) to characterize spontaneous EEG activity during different stage...
Conference Paper
Decoding upper-limb movements in invasive recordings has become a reality, but neural tuning in non-invasive low-frequency recordings is still under discussion. Recent studies managed to decode movement positions and velocities using linear decoders, even developing an online system. The decoded signals, however, exhibited smaller amplitudes than a...
Conference Paper
Spatial and frequency characterization of sleep spindles have been extensively addressed using M/EEG or fMRI recordings. However, its intraindividual variability across time has not been addressed. Here we propose to assess the intraindividual variability of sleep spindles in a time-resolved way by means of a trial-to-trial-variability (TTV) measur...
Article
Full-text available
The reference standard to diagnose pediatric Obstructive Sleep Apnea (OSA) syndrome is an overnight polysomnographic evaluation. When polysomnography is either unavailable or has limited availability, OSA screening may comprise the automatic analysis of a minimum number of signals. The primary objective of this study was to evaluate the complementa...
Article
Background and objective The location of the optic disc (OD) and the fovea is usually crucial in automatic screening systems for diabetic retinopathy. Previous methods aimed at their location often fail when these structures do not have the standard appearance. The purpose of this work is to propose novel, robust methods for the automatic detection...
Article
Objective: The analysis of particular (electroencephalographic) EEG frequency bands has revealed new insights relative to the neural dynamics that, when studying the EEG spectrum as a whole, would have remained hidden. This study is aimed at characterizing spectral resting state EEG patterns for assessing possible differences of episodic and chron...
Article
Introducción y objetivos. La hipoacusia supone un severo hándicap para cualquier profesional cuya actividad se base en el reconocimiento de sonidos. En el caso de profesionales sanitarios, la auscultación constituye una actividad rutinaria y el padecimiento de hipoacusia la limita en grado variable en función de la severidad de la misma. Aquellos p...