A5061493031- Functional Brain Connectivity Studies
- Advanced MRI Techniques and Applications
- Neural dynamics and brain function
- Advanced Neuroimaging Techniques and Applications
- EEG and Brain-Computer Interfaces
- Optical Imaging and Spectroscopy Techniques
- Cerebrospinal fluid and hydrocephalus
- Research in Social Sciences
- Schizophrenia research and treatment
- Traumatic Brain Injury and Neurovascular Disturbances
- Non-Invasive Vital Sign Monitoring
- Atomic and Subatomic Physics Research
- Epilepsy research and treatment
- Autism Spectrum Disorder Research
- Photoacoustic and Ultrasonic Imaging
- Sleep and Wakefulness Research
- Heart Rate Variability and Autonomic Control
- Blind Source Separation Techniques
- Forest Management and Policy
- Attention Deficit Hyperactivity Disorder
- Neuroscience and Neuropharmacology Research
- Healthcare Systems and Technology
- Neonatal and fetal brain pathology
- Peatlands and Wetlands Ecology
- Neural and Behavioral Psychology Studies
University of Oulu
2016-2025
Oulu University Hospital
2015-2024
University of Eastern Finland
2009
University of Minnesota
2005
Although it is being successfully implemented for exploration of the genome, discovery science has eluded functional neuroimaging community. The core challenge remains development common paradigms interrogating myriad systems in brain without constraints a priori hypotheses. Resting-state MRI (R-fMRI) constitutes candidate approach capable addressing this challenge. Imaging during rest reveals large-amplitude spontaneous low-frequency (<0.1 Hz) fluctuations fMRI signal that are temporally...
Abstract The default‐mode network (DMN) is a set of specific brain regions whose activity, predominant in the resting‐state, attenuated during cognitively demanding, externally‐cued tasks. cognitive correlates this have proven difficult to interrogate, but one hypothesis that process episodic memories and semantic knowledge integral internally‐generated mental activity. Here, we compare functional connectivity same group subjects rest conscious sedation with midazolam, state characterized by...
Baseline activity of resting state brain networks (RSN) in a subject has become one the fastest growing research topics neuroimaging. It been shown that up to 12 RSNs can be differentiated using an independent component analysis (ICA) blood oxygen level dependent (BOLD) data. In this study, we investigate how many RSN signal sources separated from entire cortex high dimension ICA group dataset. Group data 55 subjects was analyzed temporal concatenation and probabilistic algorithm....
Abstract Independent component analysis (ICA) of functional MRI data is sensitive to model order selection. There a lack knowledge about the effect increasing on independent components' (ICs) characteristics resting state networks (RSNs). Probabilistic group ICA (group PICA) 55 healthy control subjects was repeated 100 times using ICASSO repeatability software and after clustering components, centrotype components were used for further analysis. Visual signal sources (VSS), default mode...
The theory on the glymphatic convection mechanism of cerebrospinal fluid holds that cardiac pulsations in part pump from peri-arterial spaces through extracellular tissue into peri-venous facilitated by aquaporin water channels. Since pulses cannot be sole propulsion, we searched for additional human brain with ultra-fast magnetic resonance encephalography. We detected three types physiological mechanisms affecting cerebral pulsations: cardiac, respiratory, and very low frequency pulsations....
Recent evidence on resting-state networks in functional (connectivity) magnetic resonance imaging (fcMRI) suggests that there may be significant spatial variability of activity foci over time. This study used a sliding time window approach with the domain–independent component analysis (SliTICA) to detect maps The hypothesis was distribution functionally connected network would present marked stability successive sliding-window default mode (DMN) from fcMRI data 12 participants imaged...
Resting-state functional magnetic resonance imaging (rsfMRI) is a translational method with great potential in several neurobiologic applications. Most preclinical rsfMRI studies are performed anesthetized animals, but the confounding effects of anesthesia on measured connectivity (FC) poorly understood. Therefore, we FC under six commonly used protocols and compared findings data obtained from awake rats. The results demonstrated that each protocol uniquely modulated FC. Connectivity...
Ongoing neuronal activity in the CNS waxes and wanes continuously across widespread spatial temporal scales. In human brain, these spontaneous fluctuations are salient blood oxygenation level-dependent (BOLD) signals correlated within specific brain systems or “intrinsic-connectivity networks.” electrophysiological recordings, both amplitude dynamics of fast (1–100 Hz) oscillations scalp potentials per se exhibit same infra-slow (0.01–0.1 frequency range where BOLD conspicuous. While several...
Resting-state networks (RSNs) can be reliably and reproducibly detected using independent component analysis (ICA) at both individual subject group levels. Altering ICA dimensionality (model order) estimation have a significant impact on the spatial characteristics of RSNs as well their parcellation into sub-networks. Recent evidence from several neuroimaging studies suggests that human brain has modular hierarchical organization which resembles hierarchy depicted by different model orders....
Studies show evidence of longitudinal brain volume decreases in schizophrenia. We studied changes and their relation to symptom severity, level function, cognition, antipsychotic medication participants with schizophrenia control from a general population based birth cohort sample relatively long follow-up period almost decade. All members the Northern Finland Birth Cohort 1966 any psychotic disorder random not having psychosis were invited for MRI scan, clinical cognitive assessment during...
The physiological underpinnings of the necessity sleep remain uncertain. Recent evidence suggests that increases convection cerebrospinal fluid (CSF) and promotes export interstitial solutes, thus providing a framework to explain why all vertebrate species require sleep. Cardiovascular, respiratory vasomotor brain pulsations have each been shown drive CSF flow along perivascular spaces, yet it is unknown how such may change during in humans. To investigate these pulsation phenomena relation...
Signal intensity changes in fMRI during rest caused by vasomotor fluctuations were investigated this work. Resting-state baseline evaluated 12 children anesthetized with thiopental. Five subjects had related to subvoxel motion. In seven without significant motion, slow signal fluctuation at 0.025–0.041 Hz near one or more primary sensory cortices was observed. each subject the amplitude and frequency of stable. It is hypothesized that thiopental, which reduces blood pressure flow cortex,...
In this study, we applied coherence to voxel-wise measurement of regional homogeneity resting-state functional magnetic resonance imaging (RS-fMRI) signal. We compared the current method, based on (Cohe-ReHo), with previously proposed ReHo Kendall's coefficient concordance (KCC-ReHo), in terms correlation and paired t-test a large sample healthy participants. found two measurements differed mainly some brain regions where physiological noise is dominant. also sensitivity these methods...
In resting state functional magnetic resonance imaging (fMRI) studies of autism spectrum disorders (ASDs) decreased frontal-posterior connectivity is a persistent finding. However, the picture default mode network (DMN) hypoconnectivity remains incomplete. addition, analyses have been shown to be susceptible even subtle motion. DMN in ASD has specifically called for re-evaluation with stringent motion correction, which we aimed conduct by so-called scrubbing. A rich set subnetworks can...
Low image sampling rates used in resting state functional magnetic resonance imaging (rs-fMRI) may cause aliasing of the cardiorespiratory pulsations over very low frequency (VLF) BOLD signal fluctuations which reflects to connectivity (FC). In this study, we examine effect rate on currently rs-fMRI FC metrics. Ultra-fast fMRI encephalography (MREG) data, sampled with TR 0.1 s, was downsampled different subsampled repetition times (sTR, range 0.3-3 s) for comparisons. Echo planar k-space (TR...
Progressive brain volume loss in schizophrenia has been reported previous studies but its cause and regional distribution remains unclear. We investigated progressive reductions correlations with potential mediators.Participants were drawn from the Northern Finland Birth Cohort 1966. A total of 33 individuals 71 controls MRI scanned at baseline (mean age=34.7, SD=0.77) follow-up age=43.4, SD=0.44). Regional change differences associations clinical mediators examined using FSL voxelwise...
Accumulation of amyloid-β is a key neuropathological feature in brain Alzheimer's disease patients. Alterations cerebral haemodynamics, such as arterial impulse propagation driving the (peri)vascular CSF flux, predict future progression. We now present non-invasive method to quantify three-dimensional cardiovascular impulses human using ultrafast 10 Hz magnetic resonance encephalography. This technique revealed spatio-temporal abnormalities disease. The arrival latency and speed both...