Comparison between the intended and performed motor action can be expected to occur in the final epoch of a voluntary movement. In search for electrophysiological correlates of this mental process the purpose of the current study was to identify intracerebral sites activated in final epoch of self-paced voluntary movement. Intracerebral EEG was recorded from 235 brain regions of 42 epileptic patients who performed self-paced voluntary movement task. Evoked potentials starting at 0 to 243ms after the peak of averaged, rectified electromyogram were identified in 21 regions of 13 subjects. The mean amplitude value of these late movement potentials (LMP) was 56.4±27.5μV. LMPs were observed in remote regions of mesiotemporal structures, cingulate, frontal, temporal, parietal, and occipital cortices. Closely before the LMP onset, a significant increase of phase synchronization was observed in all EEG record pairs in 9 of 10 examined subjects; p<0.001, Mann-Whitney U test. In conclusion, mesiotemporal structures, cingulate, frontal, temporal, parietal, and occipital cortices seem to represent integral functionally linked parts of network activated in final epoch of self-paced voluntary movement. Activation of this large-scale neuronal network was suggested to reflect a comparison process between the intended and actually performed motor action. Our results contribute to better understanding of neural mechanisms underlying goal-directed behavior crucial for creation of agentive experience.

• MeSH
• dospělí MeSH
• elektroencefalografická fázová synchronizace fyziologie   MeSH
• elektrokortikografie metody   MeSH
• epilepsie chirurgie   MeSH
• evokované potenciály fyziologie   MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• pohybová aktivita fyziologie   MeSH
• ruka fyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

OBJECTIVE: Adaptive interactions with the outer world necessitate effective connections between cognitive and executive functions. The primary motor cortex (M1) with its control of the spinal cord motor apparatus and its involvement in the processing of cognitive information related to motor functions is one of the best suited structures of this cognition-action connection. The question arose whether M1 might be involved also in situations where no overt or covered motor action is present. METHODS: The EEG data analyzed were recorded during an oddball task in one epileptic patient (19 years) with depth multilead electrodes implanted for diagnostic reasons into the M1 and several prefrontal areas. RESULTS: The main result was the finding of an evoked response to non-target stimuli with a pronounced late component in all frontal areas explored, including three loci of the M1. The late component was implicated in the evaluation of predicted and actual action and was synchronized in all three precentral loci and in the majority of prefrontal loci. CONCLUSION: The finding is considered as direct evidence of functional involvement of the M1 in cognitive activity not related to motor function. SIGNIFICANCE: Our results contribute to better understanding of neural mechanisms underlying cognition.

• MeSH
• elektroencefalografie metody   MeSH
• kognice fyziologie   MeSH
• lidé MeSH
• mladý dospělý MeSH
• motorické korové centrum fyziologie   MeSH
• světelná stimulace metody   MeSH
• zrakové evokované potenciály fyziologie   MeSH
• Check Tag
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

• Publikační typ
• abstrakt z konference MeSH

OBJECTIVE: To identify intracerebral sites activated after correct motor response during cognitive task and to assess associations of this activity with mental processes. METHODS: Intracerebral EEG was recorded from 205 sites of frontal, temporal and parietal lobes in 18 epileptic patients, who responded by button pressing together with mental counting to target stimuli in visual oddball task. RESULTS: Post-movement event-related potentials (ERPs) with mean latency 295 ± 184 ms after movement were found in all subjects in 64% of sites investigated. Generators were consistently observed in mesiotemporal structures, anterior midcingulate, prefrontal, and temporal cortices. Task-variant nonspecific and target specific post-movement ERPs were identified, displaying no significant differences in distribution among generating structures. Both after correct and incorrect performances the post-performance ERPs were observed in frontal and temporal cortices with latency sensitive to error commission in several frontal regions. CONCLUSION: Mesiotemporal structures and regions in anterior midcingulate, prefrontal and temporal cortices seem to represent integral parts of network activated after correct motor response in visual oddball task with mental counting. Our results imply equivalent involvement of these structures in task-variant nonspecific and target specific processes, and suggest existence of common nodes for correct and incorrect responses. SIGNIFICANCE: Our results contribute to better understanding of neural mechanisms underlying goal-directed behavior.

• MeSH
• dospělí MeSH
• elektroencefalografie metody   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• mozek fyziologie   MeSH
• pohyb fyziologie   MeSH
• psychomotorický výkon fyziologie   MeSH
• světelná stimulace metody   MeSH
• zrakové evokované potenciály fyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

• Klíčová slova
• EBS,
• MeSH
• dospělí MeSH
• elektroencefalografická fázová synchronizace * MeSH
• elektroencefalografie * MeSH
• epilepsie diagnóza   MeSH
• klinická studie jako téma MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• práce podpořená grantem MeSH

Obranné chování je u vyšších živočichů řízeno nervovým systémem. Při detekci nebezpečí se u savců včetně člověka aktivují velmi podobné struktury a mechanismy, které zajišťují fyziologické odpovědi v mozku i v těle. Člověk v situacích ohrožení je navíc schopen popsat doprovázející pocit, např. strach nebo úzkost. Někdy jsou však výše jmenované pocity nepřiměřeně silné nebo neodpovídající dané situaci. Takové stavy řadíme do skupiny onemocnění označovaných jako úzkostné poruchy. Je prokázáno, že při vzniku některých z nich hrají významnou roli mozkové struktury, které se aktivují při detekci nebezpečí. Porozumění neurofyziologickým mechanismům obranného chování může být proto v této souvislosti užitečné pro klinickou praxi.

Defence behaviour in higher animals is orchestrated by nervous system. In mammals including humans, detection of threat activates very similar structures and mechanisms providing physiological responses of the brain and body. Human beings are moreover able to describe accompanying feelings, e.g. fear or anxiety. In anxiety disorders, however, these feelings are exaggerated or inadequate for a given situation. Results of recent studies bring the evidence that at least in some anxiety disorders brain structures activated by threat play an important role. In this context, the understanding of neurophysiological mechanisms of defence behaviour seems to be beneficial for clinical use.

• Klíčová slova
• mozkový systém obrany, obranná odpověď, pocity,
• MeSH
• amygdala fyziologie   MeSH
• chování a mechanismy chování * fyziologie   MeSH
• emoce fyziologie   MeSH
• extinkce (psychologie) fyziologie   MeSH
• hipokampus fyziologie   MeSH
• hormony fyziologie   MeSH
• krysa rodu rattus fyziologie   psychologie   MeSH
• lidé MeSH
• neurotransmiterové látky fyziologie   MeSH
• paměť fyziologie   MeSH
• podmiňování (psychologie) fyziologie   MeSH
• spánkový lalok fyziologie   MeSH
• strach * fyziologie   MeSH
• substantia grisea centralis fyziologie   MeSH
• úzkost * patofyziologie   MeSH
• úzkostné poruchy etiologie   patofyziologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus fyziologie   psychologie   MeSH
• lidé MeSH
• zvířata MeSH
• Publikační typ
• přehledy MeSH

Recent findings suggest that neural complexity reflecting a number of independent processes in the brain may characterize typical changes during epileptic seizures and may enable to describe preictal dynamics. With respect to previously reported findings suggesting specific changes in neural complexity during preictal period, we have used measure of pointwise correlation dimension (PD2) as a sensitive indicator of nonstationary changes in complexity of the electroencephalogram (EEG) signal. Although this measure of complexity in epileptic patients was previously reported by Feucht et al (Applications of correlation dimension and pointwise dimension for non-linear topographical analysis of focal onset seizures. Med Biol Comput. 1999;37:208-217), it was not used to study changes in preictal dynamics. With this aim to study preictal changes of EEG complexity, we have examined signals from 11 multicontact depth (intracerebral) EEG electrodes located in 108 cortical and subcortical brain sites, and from 3 scalp EEG electrodes in a patient with intractable epilepsy, who underwent preoperative evaluation before epilepsy surgery. From those 108 EEG contacts, records related to 44 electrode contacts implanted into lesional structures and white matter were not included into the experimental analysis.The results show that in comparison to interictal period (at about 8-6 minutes before seizure onset), there was a statistically significant decrease in PD2 complexity in the preictal period at about 2 minutes before seizure onset in all 64 intracranial channels localized in various brain sites that were included into the analysis and in 3 scalp EEG channels as well. Presented results suggest that using PD2 in EEG analysis may have significant implications for research of preictal dynamics and prediction of epileptic seizures.

• MeSH
• elektroencefalografie * metody   MeSH
• epilepsie patofyziologie   MeSH
• lidé MeSH
• mladý dospělý MeSH
• Check Tag
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• práce podpořená grantem MeSH

A hippocampal-prominent event-related potential (ERP) with a peak latency at around 450 ms is consistently observed as a correlate of hippocampal activity during various cognitive tasks. Some intracranial EEG studies demonstrated that the amplitude of this hippocampal potential was greater in response to stimuli requiring an overt motor response, in comparison with stimuli for which no motor response is required. These findings could indicate that hippocampal-evoked activity is related to movement execution as well as stimulus evaluation and associated memory processes. The aim of the present study was to investigate the temporal relationship between the hippocampal negative potential latency and motor responses. We analyzed ERPs recorded with 22 depth electrodes implanted into the hippocampi of 11 epileptic patients. Subjects were instructed to press a button after the presentation of a tone. All investigated hippocampi generated a prominent negative ERP peaking at ~420 ms. In 16 from 22 cases, we found that the ERP latency did not correlate with the reaction time; in different subjects, this potential could either precede or follow the motor response. Our results indicate that the hippocampal negative ERP occurs independently of motor execution. We suggest that hippocampal-evoked activity, recorded in a simple sensorimotor task, is related to the evaluation of stimulus meaning within the context of situation.

• MeSH
• akustická stimulace MeSH
• dospělí MeSH
• elektroencefalografie MeSH
• evokované potenciály fyziologie   MeSH
• hipokampus fyziologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• neparametrická statistika MeSH
• pohyb fyziologie   MeSH
• psychomotorický výkon fyziologie   MeSH
• reakční čas fyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

In this study, we tested the hypothesis that experimental stress induces a specific change of left-right electrodermal activity (EDA) coupling pattern, as indexed by pointwise transinformation (PTI). Further, we hypothesized that this change is associated with scores on psychometric measures of the chronic stress-related psychopathology. Ninety-nine university students underwent bilateral measurement of EDA during rest and stress-inducing Stroop test and completed a battery of self-report measures of chronic stress-related psychopathology. A significant decrease in the mean PTI value was the prevalent response to the stress conditions. No association between chronic stress and PTI was found. Raw scores of psychometric measures of stress-related psychopathology had no effect on either the resting levels of PTI or the amount of stress-induced PTI change. In summary, acute stress alters the level of coupling pattern of cortico-autonomic influences on the left and right sympathetic pathways to the palmar sweat glands. Different results obtained using the PTI, EDA laterality coefficient, and skin conductance level also show that the PTI algorithm represents a new analytical approach to EDA asymmetry description.

• MeSH
• algoritmy * MeSH
• detekce lži * MeSH
• dospělí MeSH
• galvanická kožní odpověď * MeSH
• kůže patofyziologie   MeSH
• lidé MeSH
• psychický stres diagnóza   patofyziologie   MeSH
• psychometrie metody   MeSH
• reprodukovatelnost výsledků MeSH
• senzitivita a specificita MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Different mental operations were expected in the late phase of intracerebral ERPs obtained in the visual oddball task with mental counting. Therefore we searched for late divergences of target and nontarget ERPs followed by components exceeding the temporal window of the P300 wave. Electrical activity from 152 brain regions of 14 epileptic patients was recorded by means of depth electrodes. Average target and nontarget records from 1800 ms long EEG periods free of epileptic activity were compared. Late divergence preceded by almost identical course of the target and nontarget ERPs was found in 16 brain regions of 6 patients. The mean latency of the divergence point was 570+/-93 ms after the stimulus onset. The target post-divergence section of the ERP differed from the nontarget one by opposite polarity, different latency of the components, or even different number of the components. Generators of post-divergence ERP components were found in the parahippocampal gyrus, superior, middle and inferior temporal gyri, amygdala, and fronto-orbital cortex. Finding of late divergence indicates that functional differences exist even not sooner than during the final phase of the task.

• MeSH
• časové faktory MeSH
• dospělí MeSH
• duševní procesy MeSH
• elektroencefalografie MeSH
• epilepsie patofyziologie   psychologie   MeSH
• kognitivní evokované potenciály P300 MeSH
• lidé středního věku MeSH
• lidé MeSH
• matematické pojmy MeSH
• mladý dospělý MeSH
• mozek patofyziologie   MeSH
• mozkové vlny MeSH
• plnění a analýza úkolů MeSH
• reakční čas MeSH
• světelná stimulace MeSH
• zraková percepce MeSH
• zrakové evokované potenciály MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH