circuit theory
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OBJECTIVES: Patients with schizophrenia have difficulties processing the emotional and cognitive states of others. Neuroimaging studies show inconsistent findings. METHODS: We used a Seed-based d Mapping meta-analytic method to explore brain activation during facial emotion recognition and theory of mind tasks in schizophrenia patients. RESULTS: The patients showed lesser recruitment of the facial emotion processing network; behavioural performance was associated with the activation of the precentral gyrus. We found abnormal activation of the mentalising network in schizophrenia patients during reasoning about other people's mental states; patients with worse performances showed lesser activation in the right insula and superior temporal gyrus. Multimodal meta-analysis showed overlaps of brain-related abnormalities for both modalities in schizophrenia, with reduced recruitment of the right insula, anterior cingulate and medial prefrontal cortex and increased activation in the bilateral parietal cortex. Meta-regression results indicate that illness duration, medication and symptomatology might influence social-cognitive network disruptions in schizophrenia. CONCLUSIONS: These findings suggest the complex impairment of social cognition, as demonstrated by neural-related circuit disruptions during facial emotion processing and theory of mind tasks in schizophrenia.
- MeSH
- emoce * MeSH
- lidé MeSH
- magnetická rezonanční tomografie MeSH
- mapování mozku MeSH
- neurozobrazování MeSH
- schizofrenie (psychologie) MeSH
- schizofrenie patofyziologie MeSH
- sociální chování * MeSH
- teorie mysli * MeSH
- výraz obličeje MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- metaanalýza MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
The ubiquitous feature of the nervous system of wide spread occurrence of complex dynamics behaviour is treated. The cardinal question concerning the nature of generators of such complex behaviour, namely if it is ad hoc random or deterministic but strongly nonlinear, is analyzed. It is proved analytically that the discrete dynamics of single neurons with the sigmoidal transfer function is potentially chaotic. As the by-product the functional gain-threshold mechanism in neurons is derived. This allows for the new interpretations of famous experiments by Miyashita on squirell monkeys. Then it is shown that the continuous dynamics of the neural circuits of two-three neurons are endowed with the potentiality of chaotic firing, too. Finally, it will be argued that the classical dogma of stochastic or the ad hoc random neural coding can be taken as the limiting case of presenting new approach of deterministic or chaotic paradigm.
Visuospatial perspective-taking (VPT) is a process of imagining what can be seen and how a scene looks from a location and orientation in space that differs from one's own. It comprises two levels that are underpinned by distinct neurocognitive processes. Level-2 VPT is often studied in relation to two other cognitive phenomena, object mental rotation (oMR) and theory of mind (ToM). With the aim to describe the broad picture of neurocognitive processes underlying level-2 VPT, here we give an overview of the recent behavioral and neuroscientific findings of level-2 VPT. We discuss its relation to level-1 VPT, which is also referred to as perspective-tracking, and the neighboring topics, oMR and ToM. Neuroscientific research shows that level-2 VPT is a diverse cognitive process, encompassing functionally distinct neural circuits. It shares brain substrates with oMR, especially those parietal brain areas that are specialized in spatial reasoning. However, compared to oMR, level-2 VPT involves additional activations in brain structures that are typically involved in ToM tasks and deal with self/other distinctions. In addition, level-2 VPT has been suggested to engage brain areas coding for internal representations of the body. Thus, the neurocognitive model underpinning level-2 VPT can be understood as a combination of visuospatial processing with social cognition and body schema representations.
- MeSH
- imaginace fyziologie MeSH
- lidé MeSH
- mozková kůra fyziologie MeSH
- teorie mysli fyziologie MeSH
- vnímání prostoru fyziologie MeSH
- zraková percepce fyziologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
Seizures beget seizures is a longstanding theory that proposed that seizure activity can impact the structural and functional properties of the brain circuits in ways that contribute to epilepsy progression and the future occurrence of seizures. Originally proposed by Gowers, this theory continues to be quoted in the pathophysiology of epilepsy. We critically review the existing data and observations on the consequences of recurrent seizures on brain networks and highlight a range of factors that speak for and against the theory. The existing literature demonstrates clearly that ictal activity, especially if recurrent, induces molecular, structural, and functional changes including cell loss, connectivity reorganization, changes in neuronal behavior, and metabolic alterations. These changes have the potential to modify the seizure threshold, contribute to disease progression, and recruit wider areas of the epileptic network into epileptic activity. Repeated seizure activity may, thus, act as a pathological positive-feedback mechanism that increases seizure likelihood. On the other hand, the time course of self-limited epilepsies and the presence of seizure remission in two thirds of epilepsy cases and various chronic epilepsy models oppose the theory. Experimental work showed that seizures could induce neural changes that increase the seizure threshold and decrease the risk of a subsequent seizure. Due to the complex nature of epilepsies, it is wrong to consider only seizures as the key factor responsible for disease progression. Epilepsy worsening can be attributed to the various forms of interictal epileptiform activity or underlying disease mechanisms. Although seizure activity can negatively impact brain structure and function, the "seizures beget seizures" theory should not be used dogmatically but with extreme caution.
- MeSH
- epilepsie * MeSH
- lidé MeSH
- mozek MeSH
- neurony MeSH
- progrese nemoci MeSH
- záchvaty * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
INTRODUCTION: The Attention Deficit Hyperactivity Disorder (ADHD) causes serious interpersonal problems from childhood to adulthood, one of them being problematic social functioning. This phenomenon in ADHD should be associated with impairments in the Theory of Mind (ToM). Therefore, understanding the neural correlates of the ToM could be crucial for helping individuals with ADHD with their social functioning. Thus, we aimed to review published literature concerning neuroanatomical and functional correlates of ToM deficits in children and adolescents with ADHD. METHODS: We reviewed studies published between 1970 and 2023. In accordance with PRISMA guidelines, after data from three databases were collected, two authors (LN and PM) independently screened all relevant records (n=638) and consequently, both authors did the data extraction. The quality of the included studies (n=5) was measured by a modified version of The Newcastle-Ottawa Scale and by measures specific for our study. This systematic review was registered on PROSPERO (CRD42020139847). RESULTS: Results indicated that impairments in performing of the ToM tasks were negatively associated with the grey matter volume in the bilateral amygdala and hippocampus in both, ADHD and control group. In EEG studies, a significantly greater electrophysiological activity during ToM tasks was observed in the, frontal, temporal, parietal and occipital lobes in participants with ADHD as compared to healthy subjects. CONCLUSION: More research is needed to explore the ToM deficits in children with ADHD. Future research might focus on the neural circuits associated with attention and inhibition, which deficits seems to contribute to the ToM deficits in children and adolescents with ADHD.
Sound localization in mammals uses two distinct neural circuits, one for low- and one for high-frequency bands. Recent experiments call for revision of the theory explaining how the direction of incoming sound is calculated. We propose such a revised theory. Our theory is based on probabilistic spiking and probabilistic delay of spikes from both sides. We have applied the mechanism originally proposed as an operation on spike trains resulting in multiplication of firing rates. We have adapted this mechanism for the case of synchronous spike trains. The mechanism has to detect spikes from both sides within a short time window. Therefore, in both circuits neurons act as coincidence detectors. In the excitatory low-frequency circuit we call the mechanism the excitatory coincidence detection, to distinguish it from the mechanism of the inhibitory coincidence detection in the high-frequency circuit. The times to first spike and gains of the two mechanisms are calculated. We show how the output gains of the mechanisms predict the dip within the human frequency sensitivity range. This dip has been described in human psychophysical experiments.
Psychopatie je pojem s dlouhou tradicí. Současný čtyřfaktorový model popisuje psychopatii v proměnných, týkajících se - interpersonálních vztahů, - afektivity, - životního stylu, a - antisociálních rysů chování. Strukturální ani funkční neuronální povaha psychopatie není plně objasněna. Patofyziologický podklad psychopatie popisuje hypotéza somatických markerů a teorie mechanismu inhibice násilného chování. Psychopatii koreluje dysfunkce systému prefrontální kůra – temporální kůra – limbický systém.
The concept of psychopathy has a long tradition. The contemporary four-factor model describes psychopathy in – interpersonal, – affective, – lifestyle, and – antisocial variables. The structural and functional neuronal basis of psychopathy has not been fully elucidated. There are two pathophysiological theories of psychopathy: somatic marker hypothesis and violence inhibition mechanism theory. Psychopathy is associated with dysfunction of the prefrontal-temporal-limbic system circuit.
- Klíčová slova
- psychopatie, čtyřfaktorový model, prefrontální, temporální, limbický obvod,
- MeSH
- asociální osobnost diagnóza patofyziologie psychologie MeSH
- lidé MeSH
- limbický systém patofyziologie MeSH
- machiavellismus MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mozková kůra patofyziologie zranění MeSH
- nemoci mozku diagnóza patofyziologie psychologie MeSH
- poranění mozku MeSH
- poruchy chování u dětí MeSH
- poruchy osobnosti MeSH
- psychologické modely MeSH
- psychopatologie MeSH
- teoretické modely MeSH
- Check Tag
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- úvodní články MeSH
European freshwater ecosystems have undergone significant human-induced and environmentally-driven variations in nutrient export from catchments throughout the past five decades, mainly in connection with changes in land-use, agricultural practice, waste water production and treatment, and climatic conditions. We analysed the relations among concentration of total phosphorus (TP) in the Slapy Reservoir (a middle reservoir of the Vltava River Cascade, Czechia), and socio-economic and climatic factors from 1963 to 2015. The study was based on a time series analysis, using conventional statistical tools, and the identification of breaking points, using a segmented regression. Results indicated clear long-term trends and seasonal patterns of TP, with annual average TP increasing up until 1991 and decreasing from 1992 to 2015. Trends in annual, winter and spring average TP concentrations reflected a shift in development of sewerage and sanitary infrastructure, agricultural application of fertilizers, and livestock production in the early 1990s that was associated with changes from the planned to the market economy. No trends were observed for average TP in autumn. The summer average TP has fluctuated with increased amplitude since 1991 in connection with recent climate warming, changes in thermal stratification stability, increased water flow irregularities, and short-circuiting of TP-rich inflow during high flow events. The climate-change-induced processes confound the generally declining trend in lake-water TP concentration and can result in eutrophication despite decreased phosphorus loads from the catchment. Our findings indicate the need of further reduction of phosphorus sources to meet ecological quality standards of the EU Water Framework Directive because the climate change may lead to a greater susceptibility of the aquatic ecosystem to the supply of nutrients.
OBJECTIVE: Recent evidence indicates that in psychiatric patients with schizophrenia and depression, lateralized EDA changes linked to temporal-limbic electrophysiological dysfunction occur. These clinical findings provide evidence for brain asymmetry and disruptions related to integrative brain activity in pathological conditions. METHODS: These changes in brain asymmetry may be assessed by linear analysis of EDA measurement and nonlinear analysis of brain complexity calculated as information entropy. Two groups of patients with established diagnosis of paranoid schizophrenia (N=35), unipolar depression (N=35) and a control group of 35 healthy controls were examined by measurement of bilateral electrodermal activity (EDA). In non-linear data analysis of the EDA time series in resting state the method of recurrence quantification analysis was applied. RESULTS: In these patients significant right-left EDA asymmetry and asymmetry of information entropy calculated by non-linear recurrence quantification analysis of EDA records have been found. Similar asymmetry has not been observed in the group of healthy controls. CONCLUSIONS: Because information entropy reflects the complexity of the deterministic structure in the system, then unilaterally increased entropy in patients with schizophrenia and depression likely indicates specific nonlinear disturbances in limbic circuits that modulate EDA. These data are in accordance with recent findings that indicate apparent differences in nonlinear neural patterns in the psychiatric diseases and nonlinear behavior of healthy brain.
- MeSH
- deprese patofyziologie MeSH
- dospělí MeSH
- elektrofyziologie MeSH
- financování organizované MeSH
- funkční lateralita fyziologie MeSH
- galvanická kožní odpověď fyziologie MeSH
- klinické zkoušky kontrolované jako téma MeSH
- kůže inervace patofyziologie MeSH
- lidé MeSH
- nelineární dynamika MeSH
- schizofrenie patofyziologie MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
Interaural time difference (ITD) is a major cue for sound azimuth localization at lower sound frequencies. We review two theories of how the sound localization neural circuit works. One of them proposes labeling of sound direction in the array of delay lines by maximal response of the tuning curve (Jeffress model). The other proposes detection of the direction by calculating the maximum slope of tuning curves. We formulate a simple hypothesis from this that stochastic neural response infers sound direction from this maximum slope, which supports the second theory. We calculate the output spike time density used in the readout of sound direction analytically. We show that the numerical implementation of the model yields results similar to those observed in experiments in mammals. We then go one step further and show that our model also gives similar results when a detailed implementation of the cochlear implant processor and simulation of implant to auditory nerve transduction are used, instead of the simplified model of auditory nerve input. Our results are useful in explaining some recent puzzling observations on the binaural cochlear implantees.
- MeSH
- akční potenciály fyziologie MeSH
- akustická stimulace MeSH
- kochleární implantáty MeSH
- lidé MeSH
- lokalizace zvuku fyziologie MeSH
- modely neurologické MeSH
- nervový přenos fyziologie MeSH
- nervus cochlearis fyziologie MeSH
- sluchová dráha fyziologie MeSH
- stochastické procesy MeSH
- teoretické modely MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
