INTRODUCTION: Altered subjective visual sensitivity manifests as feelings of discomfort or overload elicited by intense and irritative visual stimuli. This can result in a host of visual aberrations including visual distortions, elementary visual hallucinations and visceral responses like dizziness and nausea, collectively referred to as "pattern glare." Current knowledge of the underlying neural mechanisms has focused on overall excitability of the visual cortex, but the individual contribution of excitatory and inhibitory systems has not yet been quantified. METHODS: In this study, we focus on the role of glutamate and γ-aminobutyric acid (GABA) as potential mediators of individual differences in subjective visual sensitivity, measured by a computerized Pattern Glare Test-a series of monochromatic square-wave gratings with three different spatial frequencies, while controlling for psychological variables related to sensory sensitivity with multiple questionnaires. Resting neurotransmitter concentrations in primary visual cortex (V1) and right anterior insula were studied in 160 healthy participants using magnetic resonance spectroscopy. RESULTS: Data showed significant differences in the perception of visual distortions (VD) and comfort scores between men and women, with women generally reporting more VD, and therefore the modulatory effect of sex was considered in a further examination. A general linear model analysis showed a negative effect of occipital glutamate on a number of reported visual distortions, but also a significant role of several background psychological traits. When assessing comfort scores in women, an important intervening variable was the menstrual cycle. DISCUSSION: Our findings do not support that baseline neurotransmitter levels have a significant role in overreactivity to aversive stimuli in neurotypical population. However, we demonstrated that biological sex can have a significant impact on subjective responses. Based on this additional finding, we suggest that future studies investigate aversive visual stimuli while examining the role of biological sex.
- Klíčová slova
- GABA, Pattern Glare Test, cortical excitability, glutamate, magnetic resonance spectroscopy, visual discomfort,
- Publikační typ
- časopisecké články MeSH
BACKGROUND: A growing body of literature shows that psychological distress is not only a major threat to psychological well-being but can also have a significant impact on physical health. In cancer patients, it can negatively affect prognosis and posttreatment recovery processes. Since face-to-face psychological interventions are often inaccessible to cancer patients, researchers have recently been focusing on the effectiveness of eHealth adaptations of well-established approaches. In this context, there has been a call for high-quality randomised controlled trials that would allow for a direct comparison of different approaches, potentially addressing different needs and preferences of patients, and also for more systematic research focusing on how psychological interventions affect not only psychological but also biological markers of stress. Both of these questions are addressed in the present study. METHODS: A randomised controlled trial will be carried out to test and compare the effectiveness of three eight-week eHealth programmes for the mental health support of cancer patients. All programmes will be delivered through the same application for mobile devices MOU MindCare. N = 440 of breast cancer survivors will be recruited at the end of their adjuvant treatment (chemotherapy, radiotherapy, or both) and randomly assigned to one of the three interventions - Mindfulness-Based Cognitive Therapy for Cancer (MBCT-Ca), Positive Psychology (PP), or Autogenic Training (AT) - or the treatment-as-usual (TAU) control group. Psychological and biological markers of stress and adaptive functioning will be assessed at baseline (T0), post-treatment (T1), three-month follow-up (T2), and nine-month follow-up (T3). Primary outcomes will include heart-rate variability and self-report measures of depression, anxiety, perceived stress, general quality of life, and positive mental health. Secondary outcomes will include the levels of serum cortisol and immunomarkers, sleep quality, fatigue, common health symptoms, and several transdiagnostic psychological variables that are expected to be specifically affected by the MBCT-Ca and PP interventions, including dispositional mindfulness, emotion regulation, self-compassion, perceived hope, and gratitude. The data will be analysed using the mixed model repeated measures (MMRM) approach. DISCUSSION: This trial is unique in comparing three different eHealth interventions for cancer patients based on three well-established approaches to mental health support delivered on the same platform. The study will allow us to examine whether different types of interventions affect different indicators of mental health. In addition, it will provide valuable data regarding the effects of stress-reducing psychological interventions on the biomarkers of stress playing an essential role in cancer recovery processes and general health.
- Klíčová slova
- Autogenic training, Biomarkers of stress, Mindfulness-based intervention, Positive psychology intervention, Psycho-oncology, e-mental health,
- Publikační typ
- časopisecké články MeSH
This study investigated whether differences between personality styles in the processing of social stimuli reflect variability in underlying general-purpose or social-specific neurocognitive mechanisms. Sixty-five individuals classified previously into two distinct personality profiles underwent high-density electroencephalography whilst performing tasks that tap into both aspects of cognitive processing - namely, two distinct facets of general-purpose response inhibition (interference resolution and action withholding) during social information processing. To determine the stage of processing at which personality differences manifest, we assessed event-related components associated with the early visual discrimination of social stimuli (N170, N190) and later more general conflict-related processes (N2, P3). Although a performance index of interference resolution was comparable between the personality profiles, differences were detected in action withholding. Specifically, individuals expressing a wider repertoire of personality styles and more adaptive emotion regulation performed significantly better at withholding inappropriate actions to neutral faces presented in emotional contexts compared with those exhibiting stronger preferences for fewer and less adaptive personality styles and more ruminative affective tendencies. At the neurophysiological level, however, difference between the profiles was observed in brain responses elicited to the same stimuli within the N170. These results indicate that neural processes related to early visual discrimination might contribute to differences in the suppression of inappropriate responses towards social stimuli in populations with different personality dispositions.
- Klíčová slova
- action orientation, action withholding, interference resolution, personality, response inhibition, social cognition,
- MeSH
- elektroencefalografie * metody MeSH
- emoce fyziologie MeSH
- evokované potenciály * fyziologie MeSH
- kognice fyziologie MeSH
- lidé MeSH
- osobnost MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
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 externally-triggered sounds while receiving synchronous or false auditory cardiac feedback. The results found that interaction of interoceptive manipulation and action-effect processing modulates the frontal subcomponent of the P3 response. During the synchronous cardiac feedback, the P3 response to self-initiated tones was enhanced. During the false cardiac feedback, the frontal cortical response was reversed. N1 and P2 components were affected by the interoceptive manipulation, but not by the interaction of interoception and action processing. These findings provide experimental support for the theoretical accounts of the interaction between interoception and action processing within a framework of predictive coding, manifested particularly in the higher stages of action processing.
- Klíčová slova
- Action-effect processing, Agency, Event-related potentials (ERP), Interoception, Motor prediction, Predictive coding, Sensory attenuation,
- MeSH
- arousal MeSH
- evokované potenciály fyziologie MeSH
- interocepce * fyziologie MeSH
- lidé MeSH
- senzorická zpětná vazba MeSH
- srdce MeSH
- srdeční frekvence fyziologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Objective: Body image disturbances and the attendant negative emotions are two of the major clinical symptoms of eating disorders. The objective of the present experimental study was to shed more light on the degree of association or dissociation between the physiological and emotional response to mirror exposure in patients with restrictive mental anorexia, and on the relationships between the physiological response and characteristics connected with emotional processing. Materials and Methods: Thirty adolescent girls with the restrictive type of anorexia and thirty matched healthy controls underwent bilateral measurement of skin conductance (SC) during rest, neutral stimulus exposure, and mirror exposure, and completed a set of measures focused on emotion regulation competencies, affectivity, and eating disorder pathology. Results: Compared to healthy controls, girls with restrictive anorexia rated mirror exposure as a subjectively more distressful experience. Differences in skin conductance response (SCR) were not significant; however, variance in SCR was substantially greater in the group of anorexia patients as compared to healthy controls. The overall skin conductance level (SCL) was lower in anorexia patients. Increase in SCR during mirror exposure, as opposed to exposure to neutral stimuli, was positively related to the tendency to experience negative emotions, interoceptive sensitivity, body dissatisfaction and suppression, but not to other symptoms of eating pathology or emotional awareness. A post hoc analysis suggested that physiological reactivity might be associated with interoceptive sensitivity to mirror exposure especially in anorectic patients. Conclusion: The study seems to demonstrate some degree of dissociation between psychophysiological reactivity and subjective response to body exposure in patients with restrictive anorexia. Factors affecting differences in psychophysiological responsiveness to body exposure in anorectic patients require further exploration.
- Klíčová slova
- anorexia nervosa, emotion awareness, interoceptive awareness, mirror exposure, skin conductance,
- Publikační typ
- časopisecké články MeSH
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. Temporal and spatial locus of these processes was examined using the combination of high-density electroencephalography, topographic analysis of variance, and source reconstruction. Instructed action, engaging representation of the response movement, was associated with distinct negativity at the parietal and centro-parietal channels starting around 750 ms before the movement, which has a source particularly in the bilateral inferior parietal lobule. This suggests that in delayed-action tasks, the process of action representation in the inferior parietal lobule may play an important part in the larger parieto-frontal activity responsible for movement selection.
- Klíčová slova
- Action representation, Action selection, Delayed action, EEG, Inferior parietal lobule, Intentional action, Lateralized readiness potential, Libet task, Prospective memory,
- MeSH
- elektroencefalografie MeSH
- léky s prodlouženým účinkem MeSH
- lidé MeSH
- mapování mozku MeSH
- pohyb * MeSH
- temenní lalok * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- léky s prodlouženým účinkem MeSH
Background: Identifying patients with intractable epilepsy who would benefit from therapeutic chronic vagal nerve stimulation (VNS) preoperatively remains a major clinical challenge. We have developed a statistical model for predicting VNS efficacy using only routine preimplantation electroencephalogram (EEG) recorded with the TruScan EEG device (Brazdil et al., 2019). It remains to be seen, however, if this model can be applied in different clinical settings. Objective: To validate our model using EEG data acquired with a different recording system. Methods: We identified a validation cohort of eight patients implanted with VNS, whose preimplantation EEG was recorded on the BrainScope device and who underwent the EEG recording according to the protocol. The classifier developed in our earlier work, named Pre-X-Stim, was then employed to classify these patients as predicted responders or non-responders based on the dynamics in EEG power spectra. Predicted and real-world outcomes were compared to establish the applicability of this classifier. In total, two validation experiments were performed using two different validation approaches (single classifier or classifier voting). Results: The classifier achieved 75% accuracy, 67% sensitivity, and 100% specificity. Only two patients, both real-life responders, were classified incorrectly in both validation experiments. Conclusion: We have validated the Pre-X-Stim model on EEGs from a different recording system, which indicates its application under different technical conditions. Our approach, based on preoperative EEG, is easily applied and financially undemanding and presents great potential for real-world clinical use.
- Klíčová slova
- EEG reactivity, efficacy prediction, epilepsy, epilepsy treatment, neurostimulation, vagal nerve stimulation,
- Publikační typ
- časopisecké články MeSH
Social touch seems to modulate emotions, but its brain correlates are poorly understood. Here, we investigated if frontal power band activity in the electroencephalogram (EEG) during aversive mental imagery is modulated by social touch from one's romantic partner and a stranger. We observed the highest theta and beta power when imaging alone, next so when being touched by a stranger, with lowest theta and beta activity during holding hands with the loved one. Delta power was higher when being alone than with a stranger or a partner, with no difference between the two. Gamma power was highest during the stranger condition and lower both when being alone and with the partner, while alpha power did not change as a function of social touch. Theta power displayed a positive correlation with electrodermal activity supporting its relation to emotional arousal. Attachment style modulated the effect of touch on the EEG as only secure but not insecure partner bonding was associated with theta power reductions. Because theta power was sensitive to the experimental perturbations, mapped onto peripheral physiological arousal and reflected partner attachment style we suggest that frontal theta power might serve as an EEG derived bio-marker for social touch in emotionally significant dyads.
- Klíčová slova
- Attachment, mental imagery, negative emotion, social support, theta power,
- MeSH
- afekt fyziologie MeSH
- arousal fyziologie MeSH
- dospělí MeSH
- hmatová percepce fyziologie MeSH
- imaginace fyziologie MeSH
- lidé MeSH
- mozkové vlny fyziologie MeSH
- připoutání k objektu * MeSH
- sociální interakce * MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
The electrophysiological EEG features such as high frequency oscillations, spikes and functional connectivity are often used for delineation of epileptogenic tissue and study of the normal function of the brain. The epileptogenic activity is also known to be suppressed by cognitive processing. However, differences between epileptic and healthy brain behavior during rest and task were not studied in detail. In this study we investigate the impact of cognitive processing on epileptogenic and non-epileptogenic hippocampus and the intracranial EEG features representing the underlying electrophysiological processes. We investigated intracranial EEG in 24 epileptic and 24 non-epileptic hippocampi in patients with intractable focal epilepsy during a resting state period and during performance of various cognitive tasks. We evaluated the behavior of features derived from high frequency oscillations, interictal epileptiform discharges and functional connectivity and their changes in relation to cognitive processing. Subsequently, we performed an analysis whether cognitive processing can contribute to classification of epileptic and non-epileptic hippocampus using a machine learning approach. The results show that cognitive processing suppresses epileptogenic activity in epileptic hippocampus while it causes a shift toward higher frequencies in non-epileptic hippocampus. Statistical analysis reveals significantly different electrophysiological reactions of epileptic and non-epileptic hippocampus during cognitive processing, which can be measured by high frequency oscillations, interictal epileptiform discharges and functional connectivity. The calculated features showed high classification potential for epileptic hippocampus (AUC = 0.93). In conclusion, the differences between epileptic and non-epileptic hippocampus during cognitive processing bring new insight in delineation between pathological and physiological processes. Analysis of computed iEEG features in rest and task condition can improve the functional mapping during pre-surgical evaluation and provide additional guidance for distinguishing between epileptic and non-epileptic structure which is absolutely crucial for achieving the best possible outcome with as little side effects as possible.
- Klíčová slova
- cognitive processing, functional connectivity, high frequency oscillation (HFO), hippocampus, interictal epileptiform discharge, pharmacoresistant epilepsy,
- Publikační typ
- časopisecké články MeSH
Hippocampal high-frequency electrographic activity (HFOs) represents one of the major discoveries not only in epilepsy research but also in cognitive science over the past few decades. A fundamental challenge, however, has been the fact that physiological HFOs associated with normal brain function overlap in frequency with pathological HFOs. We investigated the impact of a cognitive task on HFOs with the aim of improving differentiation between epileptic and non-epileptic hippocampi in humans. Hippocampal activity was recorded with depth electrodes in 15 patients with focal epilepsy during a resting period and subsequently during a cognitive task. HFOs in ripple and fast ripple frequency ranges were evaluated in both conditions, and their rate, spectral entropy, relative amplitude and duration were compared in epileptic and non-epileptic hippocampi. The similarity of HFOs properties recorded at rest in epileptic and non-epileptic hippocampi suggests that they cannot be used alone to distinguish between hippocampi. However, both ripples and fast ripples were observed with higher rates, higher relative amplitudes and longer durations at rest as well as during a cognitive task in epileptic compared with non-epileptic hippocampi. Moreover, during a cognitive task, significant reductions of HFOs rates were found in epileptic hippocampi. These reductions were not observed in non-epileptic hippocampi. Our results indicate that although both hippocampi generate HFOs with similar features that probably reflect non-pathological phenomena, it is possible to differentiate between epileptic and non-epileptic hippocampi using a simple odd-ball task.
- MeSH
- dospělí MeSH
- elektroencefalografie přístrojové vybavení MeSH
- epilepsie temporálního laloku diagnóza patofyziologie terapie MeSH
- hipokampus patofyziologie MeSH
- implantované elektrody MeSH
- kognice fyziologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- mozkové vlny fyziologie MeSH
- neuropsychologické testy MeSH
- refrakterní epilepsie diagnóza patofyziologie terapie 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
- pozorovací studie MeSH
- práce podpořená grantem MeSH
