Zeitschriftenaufsätze

The fictitious surface charge method (FSCM) is used for the calculation of the induced electrical field in magnetic stimulation. The method was embedded and optimized in Python. It was designed to allow for the computation of large problems. An element-wise Jacobi method was combined with vectorized matrix operations to increase the parallelization capabilities and enable GPU computing. The induced fields are compared against an analytical solution for a homogeneous sphere and a FEM solution on a realistic head model. The results for both cases show that the normalized root mean square error of less than 0.5% can be achieved with the integral-free FSCM even on low-performance computer hardware.

W artykule przedstawiono wybrane zagadnienia pracy głosem w aspekcie monitorowania jego stanu. W kontekâscie dotychczasowych (statycznych) metod analizy statusu aparatu mowy i âspiewu przedstawiono znane metody pomiaru biomarkerów fizjologicznych służ&hlink;acych do diagnozowania potencjalnych patologii. Zaprezentowano także metod&hlink;e badania i konstrukcji systemu pomiarowego, który może byâc wykorzystany do bież&hlink;acej oceny stanu narz&hlink;adów mowy i âspiewu, tak by w czasie rzeczywistym możliwe było podj&hlink;ecie adekwatnych działaân, polegaj&hlink;acych zasadniczo na czasowym zaniechaniu wydawania dâzwi&hlink;eków lub ograniczenia ich intensywnoâsci. W materiale wyeksponowano przewag&hlink;e systemu pomiarowo-kontrolnego, stanowi&hlink;acego techniczne wsparcie dla beneficjenta, nad systemem autokontroli – zawodnym przeważnie z przyczyn socjologicznych lub z powodu niedostatecznie czytelnych sygnałów ostrzegawczych, wysyłanych przez nasz organizm.

N-Interval Fourier Transform Analysis (N-FTA) allows for spectral separation of a periodic target signal from uncorrelated background interference. A N-FTA pseudo-code is presented. The spectral resolution is defined by the repetition rate of the near periodic signal. Acceptance criteria for spectral targets were defined such that the probability of accepting false positives is less than 1/1500. Simulated and recorded neural compound action potentials (CAPs) were investigated. Simulated data allowed for comparison with reference solutions demonstrating the stability of N-FTA at conditions being comparable to real world data. Background activity was assessed with small errors. Evoked target components were assessed down to power spectral density being approximately N times below the background level. Validation was completed investigating a measured CAP. In neurophysiological recordings, this approach allows for accurate separation of near periodic evoked activity from uncorrelated background activities for frequencies below 1kHz. • N-FTA allows for spectral separation of a periodic target signal from uncorrelated interference by analyzing a segment containing N target signal repetitions. • A MATLAB implementation of the algorithm is provided along with simulated and recorded data. • N-FTA was successfully validated using simulated and measured data for CAPs.

A novel multimodal experimental setup and dyadic study protocol were designed to investigate the neurophysiological underpinnings of joint action through the synchronous acquisition of EEG, ECG, EMG, respiration and kinematic data from two individuals engaged in ecologic and naturalistic cooperative and competitive joint actions involving face-to-face real-time and real-space coordinated full body movements. Such studies are still missing because of difficulties encountered in recording reliable neurophysiological signals during gross body movements, in synchronizing multiple devices, and in defining suitable study protocols. The multimodal experimental setup includes the synchronous recording of EEG, ECG, EMG, respiration and kinematic signals of both individuals via two EEG amplifiers and a motion capture system that are synchronized via a single-board microcomputer and custom Python scripts. EEG is recorded using new dry sports electrode caps. The novel study protocol is designed to best exploit the multimodal data acquisitions. Table tennis is the dyadic motor task: it allows naturalistic and face-to-face interpersonal interactions, free in-time and in-space full body movement coordination, cooperative and competitive joint actions, and two task difficulty levels to mimic changing external conditions. Recording conditions - including minimum table tennis rally duration, sampling rate of kinematic data, total duration of neurophysiological recordings - were defined according to the requirements of a multilevel analytical approach including a neural level (hyperbrain functional connectivity, Graph Theoretical measures and Microstate analysis), a cognitive-behavioral level (integrated analysis of neural and kinematic data), and a social level (extending Network Physiology to neurophysiological data recorded from two interacting individuals). Four practical tests for table tennis skills were defined to select the study population, permitting to skill-match the dyad members and to form two groups of higher and lower skilled dyads to explore the influence of skill level on joint action performance. Psychometric instruments are included to assess personality traits and support interpretation of results. Studying joint action with our proposed protocol can advance the understanding of the neurophysiological mechanisms sustaining daily life joint actions and could help defining systems to predict cooperative or competitive behaviors before being overtly expressed, particularly useful in real-life contexts where social behavior is a main feature.