phase locking value
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UNLABELLED: Schizophrenia is a complex disorder characterized by altered brain functional connectivity, detectable during both task and resting state conditions using different neuroimaging methods. To this day, electroencephalography (EEG) studies have reported inconsistent results, showing both hyper- and hypo-connectivity with diverse topographical distributions. Interpretation of these findings is complicated by volume-conduction effects, where local brain activity fluctuations project simultaneously to distant scalp regions (zero-phase lag), inducing spurious inter-electrode correlations. AIM: In the present study, we explored the network dynamics of schizophrenia using a novel functional connectivity metric-corrected imaginary phase locking value (ciPLV)-which is insensitive to changes in amplitude as well as interactions at zero-phase lag. This method, which is less prone to volume conduction effects, provides a more reliable estimate of sensor-space functional network connectivity in schizophrenia. METHODS: We employed a cross-sectional design, utilizing resting state EEG recordings from two adult groups: individuals diagnosed with chronic schizophrenia (n = 30) and a control group of healthy participants (n = 30), all aged between 18 and 55 years old. RESULTS: Our observations revealed that schizophrenia is characterized by a prevalence of excess theta (4-8 Hz) power localized to centroparietal electrodes. This was accompanied by significant alterations in inter- and intra-hemispheric functional network connectivity patterns, mainly between frontotemporal regions within the theta band and frontoparietal regions within beta/gamma bands. CONCLUSIONS: Our findings suggest that patients with schizophrenia demonstrate long-range electrophysiological connectivity abnormalities that are independent of spectral power (i.e., volume conduction). Overall, distinct hemispheric differences were present in frontotemporo-parietal networks in theta and beta/gamma bands. While preliminary, these alterations could be promising new candidate biomarkers of chronic schizophrenia.
- MeSH
- chronická nemoc MeSH
- dospělí MeSH
- elektroencefalografie * metody MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mozek patofyziologie diagnostické zobrazování MeSH
- nervová síť patofyziologie diagnostické zobrazování MeSH
- odpočinek fyziologie MeSH
- průřezové studie MeSH
- schizofrenie * patofyziologie diagnostické zobrazování MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
OBJECTIVE: The pre-surgical evaluation of epilepsy relies on the electrophysiological recordings of spontaneous seizures. During this period drug dose decreases increase the likelihood of seizures transitioning the brain from a low to high seizure likelihood state, so-called pro-ictal state. This study aimed to identify the dynamic brain changes characteristic of this transition from 386 ten-minute segments of intracranial EEG recordings of 29 patients with drug-refractory temporal lobe epilepsy. METHODS: We studied brain dynamics through mean phase locking value and relative power in gamma band, and autocorrelation function width. We further explored interactions with pro-ictal factors, such as rate of interictal spikes and high frequency oscillations, circadian and multi-day cycles, and clinical outcomes. RESULTS: We observed significant increases in gamma power in the epileptogenic zone, and critical slowing in both the epileptogenic zone and presumably healthy cortex. These changes were linked with increases in spike and high frequency oscillations rate. CONCLUSIONS: Brain dynamics changed on the slow time scale - from the beginning to the end of the multi-day interval - but did not change in the short-term during the pre-ictal interval, thus could reflect pro-ictal changes. SIGNIFICANCE: We highlight gamma power and critical slowing indices as markers of pro-ictal brain states, as well as their potential to track the seizure-related brain mechanisms during the presurgical evaluation of epilepsy patients.
- MeSH
- dospělí MeSH
- elektroencefalografie metody MeSH
- elektrokortikografie metody MeSH
- epilepsie temporálního laloku * patofyziologie diagnóza MeSH
- gama rytmus EEG * fyziologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mozek * patofyziologie MeSH
- refrakterní epilepsie * patofyziologie MeSH
- záchvaty * patofyziologie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
... Introduction 41 -- Social Contract Theory 41 -- Thomas Hobbes 42 -- Jean-Jacques Rousseau 43 -- John Locke ... ... Resolving the Dual-Role Dilemma 71 vi -- Contents -- Moral Reasoning in Psychiatry 71 -- Reflective Phase ... ... 72 -- Deliberative Phase 73 -- Reflective Phase 75 -- Deliberative Phase 76 -- Conclusion 78 -- References ... ... Disorder 104 -- DSM and Psychiatric Diagnosis 105 -- Construction of Mental Disorder Using the Fact-Value ... ... 224 -- Deliberative Phase 225 -- Conclusion 226 -- References 226 -- Epilogue: Whither Psychiatry? ...
258 s.
INTRODUCTION: Intracranial EEG (iEEG) data is a powerful way to map brain function, characterized by high temporal and spatial resolution, allowing the study of interactions among neuronal populations that orchestrate cognitive processing. However, the statistical inference and analysis of brain networks using iEEG data faces many challenges related to its sparse brain coverage, and its inhomogeneity across patients. METHODS: We review these challenges and develop a methodological pipeline for estimation of network structure not obtainable from any single patient, illustrated on the inference of the interaction among visual streams using a dataset of 27 human iEEG recordings from a visual experiment employing visual scene stimuli. 100 ms sliding window and multiple band-pass filtered signals are used to provide temporal and spectral resolution. For the connectivity analysis we showcase two connectivity measures reflecting different types of interaction between regions of interest (ROI): Phase Locking Value as a symmetric measure of synchrony, and Directed Transfer Function-asymmetric measure describing causal interaction. For each two channels, initial uncorrected significance testing at p < 0.05 for every time-frequency point is carried out by comparison of the data-derived connectivity to a baseline surrogate-based null distribution, providing a binary time-frequency connectivity map. For each ROI pair, a connectivity density map is obtained by averaging across all pairs of channels spanning them, effectively agglomerating data across relevant channels and subjects. Finally, the difference of the mean map value after and before the stimulation is compared to the same statistic in surrogate data to assess link significance. RESULTS: The analysis confirmed the function of the parieto-medial temporal pathway, mediating visuospatial information between dorsal and ventral visual streams during visual scene analysis. Moreover, we observed the anterior hippocampal connectivity with more posterior areas in the medial temporal lobe, and found the reciprocal information flow between early processing areas and medial place area. DISCUSSION: To summarize, we developed an approach for estimating network connectivity, dealing with the challenge of sparse individual coverage of intracranial EEG electrodes. Its application provided new insights into the interaction between the dorsal and ventral visual streams, one of the iconic dualities in human cognition.
- Publikační typ
- časopisecké články MeSH
... among Different Nerve Segments 90 Effects of Temperature 91 Height and Other Factors 91 Clinical Values ... ... Uses of F Waves as a Clinical Test 159 Principles and Practice 159 -- Contents • xix -- Normal Values ... ... Clinical Applications 193 Normal Values 193 -- Lesions of the Trigeminal Nerve 193 Bell’s Palsy 193 - ... ... Dispersion 289 Model for Phase Cancellation 290 Detection of Conduction Block 294 -- 6. ... ... Acquisition of Reference Values 955 Control Values 955 -- Statistical Analysis 956 False-Positive and ...
4th ed. xxix, 1146 s. : il., tab. ; 26 cm + 1 CD-ROM
- MeSH
- elektrodiagnostika metody MeSH
- elektromyografie MeSH
- nemoci míchy diagnóza MeSH
- nervové vedení fyziologie MeSH
- nervový přenos fyziologie MeSH
- neuromuskulární nemoci diagnóza MeSH
- Konspekt
- Patologie. Klinická medicína
- NLK Obory
- neurologie
- diagnostika
- NLK Publikační typ
- kolektivní monografie
... Name, 43 Type, 44 -- Representation, 44 -- Length, 44, Origin: Real versus Virtual, 44 Domain, 44 Value ... ... 304 -- Simple Queries with Calculations and Literals, 305 -- Table Aliases, 306 Retrieval of NULL Values ... ... 322 -- 7.9 Deleting Rows from a Table: The Delete Statement, 323 -- 7.10 Changing a Table\'s Row Values ... ... Cursors, 365 -- Retrieval of One Row: Host Structures with the INTO Clause, 365 -- Handling NULL Values ... ... 8.5 Automatic Error Handling: The Whenever Statement, 383 -- 8.6 Transaction Processing Statements: Lock ...
1st ed. ix, 781 s.
... Medicine with -- Magical Properties 104 -- Dynamics of Bacterial Population Growth 104 -- The Lag Phase ... ... of Growth Involves No Increase in Cell Numbers 104 -- The Exponential Phase of Growth Results in an ... ... Exponential Increase in Cell Number 105 -- The Stationary Phase Is Reached when the Number of Viable ... ... Cells Stops Increasing 106 -- The Death Phase Is Characterized by an Exponential Decrease in the Number ... ... 466 -- Perspective 20.5: Cold Medicines Are of Doubtful Value and Some May Be Harmful 467 -- Adenoviral ...
XXVIII, 812 s. : il. ; 32 cm
... Visualization of Proteins in the Cell 103 -- 4.4 Peptides Can Be Synthesized by Automated -- Solid-Phase ... ... Sanger Dideoxy Method) 146 -- 6.1.4 DNA Probes and Genes Can Be Synthesized by -- Automated Solid - Phase ... ... Model Accounts for the Kinetie Properties of Many Enzymes 200 -- 8.4.1 The Significance of Km and Vm^ Values ... ... Cells Is Synthesized by -- Three Types of RNA Polymerase 793 -- 28.2.2 Cis- and Trans-Acting Elements: Locks ...
5th ed. xvii, 974 s. : il., tab., grafy ; 32 cm
