In neuroscience, time-frequency analysis is widely used to investigate brain rhythms in brain recordings. In event-related protocols, it is applied to quantify how the brain responds to a stimulation repeated over many trials. We here focus on two common measures: the power of the transform for each single trial averaged across trials, avgPOW; and the power of the transform of the average evoked potential, POWavg. We investigate the influence of additive noise on these two measures. We quantify the expected effect using theoretical calculations, simulated data and experimental brain recordings. We also consider the case of color noise. We extract the main factors influencing the effect of noise on POWavg and avgPOW, such as the noise variance, the number of trials, the sampling rate, the type of noise, the type of time-frequency transform and the frequency of interest. When dealing with time-frequency analysis, the impact of noise on the neuroscientist's work can drastically vary depending on these factors. The present results should help researchers improve their understanding and interpretation of time-frequency diagrams, as well as optimize their experimental designs and analyses based on their neuroscientific question.
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http://dx.doi.org/10.1016/j.heliyon.2024.e35310 | DOI Listing |
Int J Behav Nutr Phys Act
January 2025
Department of Rehabilitation Medicine, West China Hospital of Sichuan University, Chengdu, China.
Background: This study aims to investigate the associations between signal-level physical activity (PA) features derived from wrist accelerometry data and cognitive status in older adults, and to evaluate their potential predictive value when combined with demographics.
Methods: We analyzed PA data from 3,363 older adults (NHATS: n = 747; NHANES: n = 2,616), with each participant contributing a complete 3-day continuous activity sequence. We extracted the most relevant PA features associated with cognitive function using feature engineering and recursive feature elimination.
Biol Psychiatry Cogn Neurosci Neuroimaging
January 2025
San Francisco Veterans Affairs Medical Center, San Francisco, CA, United States; University of California, San Francisco, San Francisco, CA, United States. Electronic address:
Background: Auditory steady-state response (ASSR) abnormalities in the 40-Hz (gamma band) frequency have been observed in schizophrenia and rodent studies of N-methyl D-aspartate glutamate receptor (NMDAR) hypofunction. However, the extent to which 40-Hz ASSR abnormalities in schizophrenia resemble deficits in 40-Hz ASSR induced by acute administration of ketamine, an NMDAR antagonist, is not yet known.
Methods: To address this knowledge gap, we conducted parallel EEG studies: a crossover, placebo-controlled ketamine drug challenge study in healthy subjects (Study 1) and a comparison of patients with schizophrenia and healthy controls subjects (Study 2).
JMIR Med Inform
January 2025
School of Software, Taiyuan University of Technology, Jingzhong, China.
Background: The prompt and accurate identification of mild cognitive impairment (MCI) is crucial for preventing its progression into more severe neurodegenerative diseases. However, current diagnostic solutions, such as biomarkers and cognitive screening tests, prove costly, time-consuming, and invasive, hindering patient compliance and the accessibility of these tests. Therefore, exploring a more cost-effective, efficient, and noninvasive method to aid clinicians in detecting MCI is necessary.
View Article and Find Full Text PDFBiol Psychol
January 2025
Institute of Psychology, Jagiellonian University, Kraków, Poland.
A classical observation in experimental psychology is a reduction in reaction time and response accuracy under time pressure (TP). This speed-accuracy tradeoff may be understood from the combined perspectives of affordance competition and urgency gating. This view implies that action programs compete with each other from stimulus onset until the final response.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Theoretical Electrical Engineering and Diagnostics of Electrical Equipment, Institute of Electrodynamics, National Academy of Sciences of Ukraine, Beresteyskiy, 56, Kyiv-57, Kyiv, 03680, Ukraine.
Power quality (PQ) disturbances, such as voltage sags, are significant issues that can lead to damage in electrical equipment and system downtime. Detecting and classifying these disturbances accurately is essential for maintaining reliable power systems. This paper introduces a novel approach to voltage sag analysis by employing wavelet packet analysis combined with energy-based feature extraction to enhance PQ monitoring.
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