Cognitive and brain connectivity trajectories in critically ill COVID-19 patients.

BACKGROUND: Multiple Organ failure (MOF) is one of the main causes of admission to the Intensive Care Unit (ICU) of patients infected with COVID-19 and can cause short- and long-term neurological deficits. OBJECTIVE: To compare the cognitive functioning and functional brain connectivity at 6-12 months after discharge in two groups of individuals with MOF, one due to COVID-19 and the other due to another cause (MOF-group), with a group of Healthy Controls (HC). METHODS: Thirty-six participants, 12 from each group, underwent a neuropsychological and neuroimaging assessment at both time-points. Functional connectivity of the resting state networks was compared between COVID-19 and HC while controlling for the effect of MOF. The association between functional connectivity and neuropsychological performance was also investigated. RESULTS: Compared to the HC, COVID-19 group demonstrated hypoconnectivity between the Default Mode Network and Salience Network. This pattern was associated with worse performance on tests of attention and information processing speed, at both time-points. CONCLUSION: The study of the association between cognitive function and brain functional connectivity in COVID-19 allows the understanding of the short- and long-term neurological alterations of this disease and promotes the development of intervention programs to improve the quality of life for this understudied population.

The structure of anticorrelated networks in the human brain.

During the performance of a specific task--or at rest--, the activity of different brain regions shares statistical dependencies that reflect functional connections. While these relationships have been studied intensely for positively correlated networks, considerably less attention has been paid to negatively correlated networks, a. k.a. anticorrelated networks (ACNs). Although the most celebrated of all ACNs is the default mode network (DMN), and has even been extensively studied in health and disease, for systematically all ACNs other than DMN, there is no comprehensive study yet. Here, we have addressed this issue by making use of three neuroimaging data sets: one of N = 192 healthy young adults to fully describe ACN, another of N = 40 subjects to compare ACN between two groups of young and old participants, and another of N = 1,000 subjects from the Human Connectome Project to evaluate the association between ACN and cognitive scores. We first provide a comprehensive description of the anatomical composition of all ACNs, each of which participated in distinct resting-state networks (RSNs). In terms of participation ranking, from highest to the lowest, the major anticorrelated brain areas are the precuneus, the anterior supramarginal gyrus and the central opercular cortex. Next, by evaluating a more detailed structure of ACN, we show it is possible to find significant differences in ACN between specific conditions, in particular, by comparing groups of young and old participants. Our main finding is that of increased anticorrelation for cerebellar interactions in older subjects. Finally, in the voxel-level association study with cognitive scores, we show that ACN has multiple clusters of significance, clusters that are different from those obtained from positive correlated networks, indicating a functional cognitive meaning of ACN. Overall, our results give special relevance to ACN and suggest their use to disentangle unknown alterations in certain conditions, as could occur in early-onset neurodegenerative diseases or in some psychiatric conditions.

A Controlled Thermoalgesic Stimulation Device for Exploring Novel Pain Perception Biomarkers.

OBJECTIVE: To develop a new device for identifying physiological markers of pain perception by reading the brain's electrical activity and hemodynamic interactions while applying thermoalgesic stimulation. METHODS: We designed a compact prototype that generates well-controlled thermal stimuli using a computer-driven Peltier cell while simultaneously capturing electroencephalography (EEG) and photoplethysmography (PPG) signals. The study was performed on 35 healthy subjects (mean age 30.46 years, SD 4.93 years; 20 males, 15 females). We first determined the heat pain threshold (HPT) for each subject, defined as the maximum temperature that the subject can withstand when the Peltier cell gradually increased the temperature. Next, we defined the painful condition as the one occurring at temperature equal to 90% of the HPT, comparing this to the no-pain state (control) in the absence of thermoalgesic stimulation. RESULTS: Both the one-dimensional and the two-dimensional spectral entropy (SE) obtained from both the EEG and PPG signals differentiated the condition of pain. In particular, the SE for PPG was significantly reduced in association with pain, while the SE for EEG increased slightly. Moreover, significant discrimination occurred within a specific range of frequencies, 26-30 Hz for EEG and about 5-10 Hz for PPG. CONCLUSION: Hemodynamics, brain dynamics and their interactions can discriminate thermal pain perception. SIGNIFICANCE: The possibility of monitoring on-line variations in thermal pain perception using a similar device and algorithms may be of interest to study different pathologies that affect the peripheral nervous system, such as small fiber neuropathies, fibromyalgia or painful diabetic neuropathy.

Lógica temporal del tiro libre en A. C. B / Temporal logic of free throwing in the Spanish A. C. B Basketball competition

A partir de datos play-by-play de nueve temporadas de la liga ACB de baloncesto (2929 partidos, 119338 intentos) se describen las propiedades estadísticas básicas de los tiros libres a partir de los factores temporales de lógica interna del juego (el tiempo de la temporada y el partido, el valor de las interacciones de marca, el estado del marcador). En este estudio se identifican por primera vez las series de tiros libres realizadas por un jugador cada vez que va a la línea de tiro libre. Las principales conclusiones son: la competencia en tiro libre parece estable a lo largo de la temporada; el rendimiento en tiro libre depende del acierto en los primeros tiros de las series; el tamaño de algunos de los efectos estadísticos encontrados parece ir demasiado en contra de las intuiciones prácticas, lo que nos debe hacer reflexionar sobre la conexión entre las decisiones del científico y las decisiones de los entrenadores (AU)

Based on play-by-play data from nine full seasons of ACB basket league (2929 games, 119338 efforts) the fundamental statistical properties of free throwing are described taking into account several time factors of the internal logic of the game (i.e. season periods and playing time of the match, the value of the different scoring interactions, score). FIn addition, and for the first time, it is possible to identify the sets of free shots taken by a player every time he goes to the line. The main conclusions were: the competence in free throwing seems stable along the season; free throwing performance depends on the success at the first shot of the series; some of the statistical effects seem practically too counterintuitive, what must make us reflect about the links between scientists’ decisions and the coaches’ decisions (AU)