Radek Mareček's research while affiliated with Masaryk University and other places

Publications (157)

Article
Full-text available
Introduction According to the strong version of the orthographic depth hypothesis, in languages with transparent letter-sound mappings (shallow orthographies) the reading of both familiar words and unfamiliar nonwords may be accomplished by a sublexical pathway that relies on serial grapheme-to-phoneme conversion. However, in languages such as Engl...
Article
Full-text available
This study focuses on white matter alterations in pharmacoresistant epilepsy patients with no visible lesions in the temporal and frontal lobes on clinical MRI (i.e. MR-negative) with lesions confirmed by resective surgery. The aim of the study was to extend the knowledge about group-specific neuropathology in MR-negative epilepsy. We used the fixe...
Article
Full-text available
The objective was to determine the optimal combination of multimodal imaging methods (IMs) for localizing the epileptogenic zone (EZ) in patients with MR-negative drug-resistant epilepsy. Data from 25 patients with MR-negative focal epilepsy (age 30 ± 10 years, 16M/9F) who underwent surgical resection of the EZ and from 110 healthy controls (age 31...
Article
Full-text available
The volume of the hippocampus decreases more slowly than the volume of the cortex during normal aging. We explored changes in the hippocampus-to-cortex volume (HV:CTV) ratio with increasing age in non-demented Parkinson’s disease (PD) patients as compared to healthy controls (HC). We also evaluated the association between the HV:CTV ratio and cogni...
Preprint
We perform a broad range of cognitive processes during social interactions; we must continuously monitor various cues from our interaction partner(s) in order to infer their mental and emotional state, and use this information to adapt our own behaviour accordingly. To support interactive behaviour, the brain must therefore be capable of recruiting...
Article
In the present study, we investigated the modulatory influence of the unconscious, bodily arousal on motor-related embodied information. Specifically, we examined how the interoceptive prediction error interacts with the event-related potentials linked to action-effect processing. Participants were asked to perform a task with self-initiated or ext...
Article
The phenomenon of déjà vu (DV) has intrigued scientists for decades, yet its neurophysiological underpinnings remain elusive. Brain regions have been identified in which morphometry differs between healthy individuals according to the frequency of their DV experiences. This study built upon these findings by assessing if and how neural activity in...
Article
Full-text available
Background: Dance is a complex activity combining physical exercise with cognitive, social, and artistic stimulation. Objectives: We aimed to assess the effects of dance intervention (DI) on intra and inter-network resting-state functional connectivity (rs-FC) and its association to cognitive changes in a group of non-demented elderly participants....
Article
Full-text available
Research on dance interventions (DIs) in the elderly has shown promising benefits to physical and cognitive outcomes. The effect of DIs on resting-state functional connectivity (rs-FC) varies, which is possibly due to individual variability. In this study, we assessed the moderation effects of residual cognitive reserve (CR) on DI-induced changes i...
Article
Background Exposure to maternal stress in utero has long-term implications for the developing brain and has been linked with a higher risk of depression. The amygdala, which develops during the early embryonic stage and is critical for emotion processing, might be particularly sensitive. Methods Using data from a neuroimaging follow-up of the ELSP...
Article
Intentional motor action is typically characterized by the decision about the timing, and the selection of the action variant, known as the “what” component. We compared free action selection with instructed action, where the movement type was externally cued, in order to investigate the action selection and action representation in a Libet’s task....
Article
Full-text available
Many methods applied to data acquired by various imaging modalities have been evaluated for their benefit in localizing lesions in magnetic resonance (MR) negative epilepsy patients. No approach has proven to be a stand‐alone method with sufficiently high sensitivity and specificity. The presented study addresses the potential benefit of the automa...
Article
Full-text available
Verbal communication relies heavily upon mutual understanding, or common ground. Inferring the intentional states of our interaction partners is crucial in achieving this, and social neuroscience has begun elucidating the intra- and inter-personal neural processes supporting such inferences. Typically, however, neuroscientific paradigms lack the re...
Article
Purpose The purpose of the study was to evaluate cerebral morphological changes in temporal lobe epilepsy with hippocampal sclerosis (TLE-HS) and their relationship to the cerebellum. Methods The study cohort included 21 patients with intractable TLE-HS (14 left-sided, 7 right-sided) and 38 healthy controls (HC). All patients later underwent anter...
Article
Full-text available
This study investigates the role of the dorsal/sensorimotor striatum in visuomotor integration (i.e., the transformation of internal visual information about letter shapes into motor output) during handwriting. Twenty healthy participants underwent fMRI scanning with tasks consisting of self-paced handwriting of alphabetically ordered single letter...
Article
Full-text available
Maternal depression during pregnancy is associated with elevated risk of anxiety and depression in offspring, but the mechanisms are incompletely understood. Here we conducted a neuroimaging follow-up of a prenatal birth cohort from the European Longitudinal Study of Pregnancy and Childhood (n = 131; 53% women, age 23-24) to test whether deviations...
Article
Full-text available
Mental imagery related to the recent death of a loved one is associated with intense sadness and distress. Social relations, such as with one's significant other, can regulate negative emotions and provide comfort, but the neural correlates of social comfort are largely unknown. In this functional magnetic resonance imaging study, we examined brain...
Article
Full-text available
Social touch may modulate emotions, but the neurobehavioral correlates are poorly understood. Here, we investigated neural responses to a picture of a deceased close person and if neural activity and connectivity are modulated by social touch from one's romantic partner. Using functional magnetic resonance imaging (fMRI) we found altered reactivity...
Article
Full-text available
In social interactions, each individual's brain drives an action that, in turn, elicits systematic neural responses in their partner that drive a reaction. Consequently, the brain responses of both interactants become temporally contingent upon one another through the actions they generate, and different interaction dynamics will be underpinned by...
Article
Full-text available
Interoception plays a key role in experiencing emotions, as it provides information about bodily arousal. Cardiac feedback manipulation proved to be a useful tool for exploring interoceptive processes. However, previous research showed inconclusive results on the influence of synchronous and false cardiac feedback on autonomic arousal. In the prese...
Article
Full-text available
Introduction: Recent studies of patients with multiple sclerosis (MS) have revealed disturbances in distinct components of social cognition, such as impaired mentalizing and empathy. The present study investigated this socio-cognitive profile in MS patients in more detail, by examining their performance on tasks measuring more fundamental component...
Chapter
Within the last decade, various blind source separation algorithms (BSS) isolating distinct EEG oscillations were derived and implemented. Group Independent Component Analysis (group-ICA) is a promising tool for decomposing spatiospectral EEG maps across multiple subjects. However, researchers are faced with many preprocessing options prior to perf...
Article
Full-text available
Background Cognitive impairment in Parkinson’s disease (PD) is associated with altered connectivity of the resting state networks (RSNs). Longitudinal studies in well cognitively characterized PD subgroups are missing. Objectives To assess changes of the whole-brain connectivity and between-network connectivity (BNC) of large-scale functional netw...
Article
Background: Spatial and temporal resolution of brain network activity can be improved by combining different modalities. Functional Magnetic Resonance Imaging (fMRI) provides full brain coverage with limited temporal resolution, while electroencephalography (EEG), estimates cortical activity with high temporal resolution. Combining them may provid...
Preprint
Dyadic interactions often involve a dynamic process of mutual reciprocity; to steer a series of exchanges towards a desired outcome, both interactants must adapt their own behaviour according to that of their interaction partner. Understanding the brain processes behind such bidirectional reciprocity is therefore central to social neuroscience, but...
Article
Full-text available
Using MRI, a characteristic pattern of grey matter (GM) atrophy has been described in the early stages of Alzheimer’s disease (AD); GM patterns at different stages of Parkinson’s disease (PD) have been inconclusive. Few studies have directly compared structural changes in groups with mild cognitive impairment (MCI) caused by different pathologies (...
Article
Full-text available
Purpose Autosomal dominant lateral temporal epilepsy (ADLTE) is a genetic focal epilepsy syndrome characterized by focal seizures with dominant auditory symptomatology. We present a case report of an 18-year-old patient with acute onset of seizures associated with epilepsy. Based on the clinical course of the disease and the results of the investig...
Article
Full-text available
This study examines the impact of using different cerebrospinal fluid (CSF) and white matter (WM) nuisance signals for data‐driven filtering of functional magnetic resonance imaging (fMRI) data as a cleanup method before analyzing intrinsic brain fluctuations. The routinely used temporal signal‐to‐noise ratio metric is inappropriate for assessing f...
Article
Full-text available
Dyadic interactions often involve a dynamic process of mutual reciprocity; to steer a series of exchanges towards a desired outcome, both interactants must adapt their own behaviour according to that of their interaction partner. Understanding the brain processes behind such bidirectional reciprocity is therefore central to social neuroscience, but...
Article
Full-text available
Introduction Morphological correlates of nonpathological déjà vu (DV) have been identified recently within the human brain. Significantly reduced gray matter volume (GMV) within a set of cortical and subcortical regions reported in subjects experiencing DV seems to mirror the distribution of GMV reduction in mesial temporal lobe epilepsy (MTLE) pat...
Article
Approximately a 1/3 of epileptic patients suffer from pharmacoresistant epilepsy. The surgery is often the only possible treatment, which brings a need for finding epileptogenic zone. The task is intricate in non-lesional patients in whom magnetic resonance imaging is uninformative. Our goal is to find a set of non-invasive imaging methods that wou...
Article
The effect of STN DBS (Deep Brain Stimulation of Subthalamic Nucleus) on the somatomotor network may differ from the effects on the cognitive networks (Rektor et al., 2015). Thus, we acquired high-density (HD) scalp EEG data from 10 Parkinson’s disease patients with STN DBS during DBS ON and OFF state while performing 3-stimulus visual oddball task...
Article
Introduction Patients with Parkinson’s disease (PD) show abnormal functional connectivity in large-scale brain networks. We explored resting state connectivity among the main networks, including the default mode network (DMN), dorsal attentional network (DAN), frontoparietal control network (FPCN) and visual network (VN) in PD patients with and wit...
Article
Full-text available
The main objective of this study was to investigate the impact of prenatal and early postnatal stress on hippocampal volume in young adulthood. In sharp contrast to numerous results in animal models, our data from a neuroimaging follow-up (n = 131) of a community-based birth cohort from the Czech Republic (European Longitudinal Study of Pregnancy a...
Article
Objective: Growing interest in the examination of large-scale brain network functional connectivity dynamics is accompanied by an effort to find the electrophysiological correlates. The commonly used constraints applied to spatial and spectral domains during EEG data analysis may leave part of the neural activity unrecognized. We propose an approa...
Article
Full-text available
Electroencephalography (EEG) oscillations reflect the superposition of different cortical sources with potentially different frequencies. Various blind source separation (BSS) approaches have been developed and implemented in order to decompose these oscillations, and a subset of approaches have been developed for decomposition of multi-subject dat...
Article
Objective: This study was designed to use statistical parametric mapping of interictal positron-emission tomography using [18F]Fluorodeoxyglucose (FDG-PET) to compare the brain metabolisms of patients with mesial temporal lobe epilepsy (MTLE)/hippocampal sclerosis and controls. Another aim of this study was to analyze the potential differences amo...
Article
Purpose: To evaluate cerebellar volume changes in temporal lobe epilepsy (TLE) patients in greater detail. We aimed to determine which discrete substructures significantly differ in patients with TLE compared to controls and the nature of this difference. Correlations with age at epilepsy onset, epilepsy duration, seizure frequency, and total numb...
Article
Full-text available
Visual processing difficulties are often present in Alzheimer’s disease (AD), even in its pre-dementia phase (i.e. in mild cognitive impairment, MCI). The default mode network (DMN) modulates the brain connectivity depending on the specific cognitive demand, including visual processes. The aim of the present study was to analyze specific changes in...
Article
Background: Although dystonia is traditionally conceptualized as a basal ganglia disorder, increasing interest has been directed at a different neural network node, the cerebellum, which may play a significant role in the pathophysiology of dystonia. Abnormal sensorimotor processing and disturbed motor schemes, possibly attributable to cerebellar...
Article
Full-text available
Objectives The aim was to describe the contribution of basal ganglia (BG) thalamo-cortical circuitry to the whole-brain functional connectivity in focal epilepsies. Methods Interictal resting-state fMRI recordings were acquired in 46 persons with focal epilepsies. Of these 46, 22 had temporal lobe epilepsy: 9 left temporal (LTLE), 13 right tempora...
Article
Full-text available
Déjà vu (DV) is an eerie phenomenon experienced frequently as an aura of temporal lobe epilepsy, but also reported commonly by healthy individuals. The former pathological manifestation appears to result from aberrant neural activity among brain structures within the medial temporal lobes. Recent studies also implicate medial temporal brain structu...
Article
Objective: The scalp EEG spectrum is a frequently used marker of neural activity. Commonly, the preprocessing of EEG utilizes constraints, e.g. dealing with a predefined subset of electrodes or a predefined frequency band of interest. Such treatment of the EEG spectrum neglects the fact that particular neural processes may be reflected in several...
Article
Background and objective: Functional magnetic resonance imaging (fMRI) studies of the human brain are appearing in increasing numbers, providing interesting information about this complex system. Unique information about healthy and diseased brains is inferred using many types of experiments and analyses. In order to obtain reliable information, i...
Article
Full-text available
Abnormalities in both time processing and dopamine (DA) neurotransmission have been observed in schizophrenia. Time processing seems to be linked to DA neurotransmission. The cognitive dysmetria hypothesis postulates that psychosis might be a manifestation of the loss of coordination of mental processes due to impaired timing. The objective of the...
Article
Background Impairment of speech prosody is characteristic for Parkinson's disease (PD) and does not respond well to dopaminergic treatment. Objectives We assessed whether baseline acoustic parameters, alone or in combination with other predominantly non-dopaminergic symptoms may predict global cognitive decline as measured by the Addenbrooke's cog...
Conference Paper
The aim of the current study is visualization of task-related variability in EEG-fMRI data, performed as a blind-search analysis without stimulus timings, using a methodology that is based on Kilner's et al. heuristic approach [2]. We show that filters of the relative EEG spectra with different frequency responses visualize different task-related b...
Article
The aim of this study was to investigate the effects of rTMS on cognitive functions in patients with mild cognitive impairment and Alzheimer’s disease (MCI/AD) and assess the effect of gray matter (GM) atrophy on stimulation outcomes. Twenty MCI/AD patients participated in the placebo-controlled study. Each patient received 3 sessions of 10 Hz rTMS...
Article
Introduction The object of our study was to detect specific alterations in default mode network (DMN) connectivity when switching from baseline to task condition in 17 patients with mild cognitive impairment (MCI) as compared to 18 healthy controls (HC) and 15 patients with Alzheimer disease (AD) using psychophysiological interactions (PPI) analysi...
Article
So far many studies have addressed the issue of connectivity changes in mild cognitive impairment (MCI) and Alzheimer’s disease (AD) using different methods, including whole-brain network analyses describing structural and functional topology. In this study we address an association between network topology and brain pathology in MCI. We investigat...
Article
Full-text available
Our ability to process complex social cues presented by faces improves during adolescence. Using multivariate analyses of neuroimaging data collected longitudinally from a sample of 38 adolescents (17 males) when they were 10, 11.5, 13 and 15 years old, we tested the possibility that there exists parallel variations in the structural and functional...
Data
Meta-analytic co-activation matrix. Meta-analytic connectivity modelling (MACM) was employed to compare the probability of co-activation between cells comprising the positive and negative pattern of structural covariance, and perform a behavioral characterisation of each pattern. The matrix presents the standardized probability of co-activation amo...
Article
The aim of the current research was to study functional connectivity (FC) of the right superior temporal sulcus (rSTS) during visual target stimulus processing. This structure is presumed to be crucial in social cognition, but evidently participates in target detection as well. Twenty subjects participated in functional magnetic resonance examinati...
Article
Full-text available
Abstract: Background: Repetitive transcranial magnetic stimulation (rTMS) is a promising tool to study and modulate brain plasticity. Objective: Our aim was to investigate the effects of rTMS on cognitive functions in patients with mild cognitive impairment and Alzheimer’s disease (MCI/AD) and assess the effect of gray matter (GM) atrophy on stimul...
Article
Full-text available
In some fields of fMRI data analysis, using correct methods for dealing with noise is crucial for achieving meaningful results. This paper provides a quantitative assessment of the effects of different preprocessing and noise filtering strategies on psychophysiological interactions (PPI) methods for analyzing fMRI data where noise management has no...
Article
In the last decade, a number of functional neuroimaging studies have identified a set of neural structures that are involved in empathy for another person's pain. Bilateral anterior insular cortex and medial/anterior cingulate cortex seem to play a crucial role, but several other brain regions are also co-activated; this includes structures associa...
Article
Resting-state networks (RSNs) are characterized by organized basal activity during rest and by low-frequency signal fluctuations that can be studied by fMRI. To date, several RSNs have been consistently reported, including the task-positive networks (e.g., the primary motor, visual and auditory network, the left and right fronto-parietal RSNs, and...
Article
Simultaneous EEG-fMRI is increasingly used for the noninvasive pre-surgical evaluation of epileptic patients to localize the epileptogenic zone. In this retrospective study of EEG-fMRI data in patients with pharmacoresistant epilepsy, we compared a wide range of data processing strategies using validation with resection masks after successful epile...
Article
Brain can be described as a complex network and its structure can be changed in disease (Rubinov and Sporns, 2010). The analysis based on graph theory is a well established tool for quantification of changes in network topology (Tijms et al., 2013; Diessen et al., 2013); so far the binary representation of connectivity network has been very popular...
Article
Objective This study was designed to use statistical parametric mapping (SPM) of preoperative interictal FDG-PET to compare the brain metabolisms of patients with mesial temporal lobe epilepsy/hippocampal sclerosis (MTLE/HS) who underwent resective surgery and controls. Another aim of this study was to analyze potential differences in SPM-PET withi...
Article
Introduction Visual processing and attentional deficits can be found in early Alzheimer’s disease (AD). Study objectives We aimed at developing a visual cognitive task to study brain mechanisms underlying visual processing in early AD using functional MRI (fMRI). To achieve our goal we developed a novel visual object matching task using convention...
Article
Full-text available
Introduction: Our aim was to investigate whether grey matter atrophy as assessed by T1-weighted MR-based brain morphometry affects cognitive outcome of repetitive transcranial magnetic stimulation (rTMS) in patients with mild cognitive impairment and early Alzheimer’s disease (MCI-AD). Methods: MCI-AD patients (n=20, age 73 ± 7 years) underwent b...
Article
The paper deals with joint analysis of fMRI and scalp EEG data, simultaneously acquired during event-related oddball experiment. The analysis is based on deriving temporal sequences of EEG powers in individual frequency bands for the selected EEG electrodes and using them as regressors in the General Linear Model (GLM). Given the infrequent use of...
Article
The resting brain exhibits continuous intrinsic activity, which is correlated between groups of regions forming resting state networks. Evaluating resting connectivity is a popular approach for studying brain diseases. Several hundred studies are now available that address integrity of resting connectivity in patients with Alzheimer's disease (AD)...
Article
Introduction: Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive tool for modulating cortical activity. Objectives: In this pilot study, we evaluated the effects of high frequency rTMS applied over the right inferior frontal gyrus (IFG) on cognitive functions in patients with amnestic mild cognitive impairment (MCI) or incipient...
Article
Background: The default mode network (DMN) decreases its activity when switching from a resting state to a cognitive task condition, while activity of the network engaged in the given task increases. Visual processing is typically disturbed in Parkinson's disease dementia (PDD). Objective: Using functional MRI, we studied the DMN effective conne...
Article
A clear concept of epileptic zones remains of high clinical relevance in presurgical evaluation of refractory epilepsy patients and in resection planning. Recent advances in understanding how each of the epileptic zones is functionally organized strengthened the importance of the network concept. It has been shown that neuronal networks underlying...