Jan Chládek

Learn More
OBJECTIVE The study was designed to investigate the neurocognitive network in the frontal and lateral temporal cortices that is activated by the complex cognitive visuomotor tasks of letter writing. METHODS Eight epilepsy surgery candidates with implanted intracerebral depth electrodes performed two tasks involving the writing of single letters. The first(More)
An infrequent change to an otherwise repetitive sequence of stimuli leads to the generation of mismatch negativity (MMN), even in the absence of attention. This evoked negative response occurs in the scalp-recorded electroencephalogram (EEG) over the temporal and frontal cortices, 100-250 ms after onset of the deviant stimulus. The MMN is used to detect(More)
We studied the appearance of cognitive event-related potentials (ERPs) and event-related de/synchronizations (ERD/S) in the subthalamic nucleus (STN) and globus pallidus internus (GPi). We particularly focused on the rare non-target (distractor) stimuli processing. ERPs and ERD/S in the alpha and beta frequency range were analyzed in seven Parkinson's(More)
Using functional neuroimaging techniques (PET and fMRI), various cortical, limbic, and paralimbic structures have been identified in the last decade as neural substrates of human emotion. In this study we used a novel approach (intracerebral recordings of event-related potentials) to add to our knowledge of specific brain regions involved in affective(More)
The occurrence of the local generators of P3-like potentials elicited by a noise-compatibility flanker test was used to study the processing of executive functions, particularly in the frontal and temporal cortices. The test performed with arrows comprised a simpler congruent and a more difficult incongruent task. The two tasks activated the attention and(More)
We studied the appearance of broadband oscillatory changes (ranging 2-45 Hz) induced by a cognitive task with two levels of complexity. The event-related de/synchronizations (ERD/S) in the subthalamic nucleus (STN) and in the anterior cingulate cortex (ACC) were evaluated in an executive function test. Four epilepsy surgery candidates with intracerebral(More)
Cognitive adverse effects were reported after the deep brain stimulation (DBS) of the anterior nucleus of the thalamus (AN) in epilepsy. As the AN may have an influence on widespread neocortical networks, we hypothesized that the AN, in addition to its participation in memory processing, may also participate in cognitive activities linked with the frontal(More)
The objective is to study the involvement of the posterior medial cortex (PMC) in encoding and retrieval by visual and auditory memory processing. Intracerebral recordings were studied in two epilepsy-surgery candidates with depth electrodes implanted in the retrosplenial cingulate, precuneus, cuneus, lingual gyrus and hippocampus. We recorded the(More)
Using intracerebral EEG recordings in a large cohort of human subjects, we investigate the time course of neural cross-talk during a simple cognitive task. Our results show that human brain dynamics undergo a characteristic sequence of synchronization patterns across different frequency bands following a visual oddball stimulus. In particular, an initial(More)
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(More)