The aim of this study was to test whether the availability of internal imagery elicited by words is related to ratings of word imageability. Participants are presented with target words and, after a delay allowing for processing of the word, answer questions regarding the size or weight of the word referents. Target words differ with respect to imageability. Results show faster responses to questions for high imageability words than for low imageability words. The type of question (size/weight) modulates reaction times suggesting a dominance of the visual domain over the physical-experience domain in concept representation. Results hold across two different languages (Czech/German). These findings provide further insights into the representations underlying word meaning and the role of word imageability in language acquisition and processing.

• MeSH
• dospělí MeSH
• imaginace * fyziologie   MeSH
• lidé MeSH
• mladý dospělý MeSH
• reakční čas * fyziologie   MeSH
• sémantika MeSH
• slovní zásoba MeSH
• světelná stimulace MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

The relationship between working memory (WM) and neuronal oscillations can be studied in detail using brain stimulation techniques, which provide a method for modulating these oscillations and thus influencing WM. The endogenous coupling between the amplitude of gamma oscillations and the phase of theta oscillations is crucial for cognitive control. Theta/gamma peak-coupled transcranial alternating current stimulation (TGCp-tACS) can modulate this coupling and thus influence WM performance. This study investigated the effects of TGCp-tACS on WM in older adults and compared their responses with those of younger participants from our previous work who underwent the same experimental design. Twenty-eight older subjects underwent both TGCp-tACS and sham stimulation sessions at least 72 h apart. Resting-state electroencephalography (EEG) was recorded before and after the interventions, and a WM task battery with five different WM tasks was performed during the interventions to assess various WM components. Outcomes measured included WM task performance (e.g., accuracy, reaction time (RT)) and changes in power spectral density (PSD) in different frequency bands. TGCp-tACS significantly decreased accuracy and RT on the 10- and 14-point Sternberg tasks and increased RT on the Digit Symbol Substitution Test in older adults. In contrast, younger participants showed a significant increase in accuracy only on the 14-item Sternberg task. Electrophysiological analysis revealed a decrease in delta and theta PSD and an increase in high gamma PSD in both younger and older participants after verum stimulation. In conclusion, theta-gamma coupling is essential for WM and modulation of this coupling affects WM performance. The effects of TGCp-tACS on WM vary with age due to natural brain changes. To better support older adults, the study suggests several strategies to improve cognitive function, including: Adjusting stimulation parameters, applying stimulation to two sites, conducting multiple sessions, and using brain imaging techniques for precise targeting.

• MeSH
• dospělí MeSH
• elektroencefalografie MeSH
• gama rytmus EEG * fyziologie   MeSH
• krátkodobá paměť * fyziologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• přímá transkraniální stimulace mozku * MeSH
• reakční čas fyziologie   MeSH
• senioři MeSH
• stárnutí fyziologie   MeSH
• theta rytmus EEG * fyziologie   MeSH
• zdraví MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Throughout human evolutionary history, snakes have been associated with danger and threat. Research has shown that snakes are prioritized by our attentional system, despite many of us rarely encountering them in our daily lives. We conducted two high-powered, pre-registered experiments (total N = 224) manipulating target prevalence to understand this heightened prioritization of threatening targets. Target prevalence refers to the proportion of trials wherein a target is presented; reductions in prevalence consistently reduce the likelihood that targets will be found. We reasoned that snake targets in visual search should experience weaker effects of low target prevalence compared to non-threatening targets (rabbits) because they should be prioritized by searchers despite appearing rarely. In both experiments, we found evidence of classic prevalence effects but (contrasting prior work) we also found that search for threatening targets was slower and less accurate than for nonthreatening targets. This surprising result is possibly due to methodological issues common in prior studies, including comparatively smaller sample sizes, fewer trials, and a tendency to exclusively examine conditions of relatively high prevalence. Our findings call into question accounts of threat prioritization and suggest that prior attention findings may be constrained to a narrow range of circumstances.

• MeSH
• biologická evoluce MeSH
• hadi MeSH
• králíci MeSH
• Lagomorpha * MeSH
• lidé MeSH
• pozornost MeSH
• reakční čas MeSH
• strach * MeSH
• zraková percepce MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND: Caffeine (CAF) ingestion improves performance in a broad range of exercise tasks. Nevertheless, the CAF-induced, dose-dependent effect on discipline-specific performance and cognitive functions in CrossFit/High-Intensity Functional Training (HIFT) has not been sufficiently investigated. The aim of this study was to evaluate the effect of acute supplementation of three different doses of CAF and placebo (PLA) on specific performance, reaction time (RTime), postural stability (PStab), heart rate (HR) and perceived exertion (RPE). METHODS: In a randomized double-blind placebo-controlled crossover design, acute pre-exercise supplementation with CAF (3, 6, or 9 mg/kg body mass (BM)) and PLA in 26 moderately trained CrossFit practitioners was examined. The study protocol involved five separate testing sessions using the Fight Gone Bad test (FGB) as the exercise performance evaluation and biochemical analyses, HR and RPE monitoring, as well as the assessment of RTime and PStab, with regard to CYP1A2 (rs762551) and ADORA2A (rs5751876) single nucleotide polymorphism (SNP). RESULTS: Supplementation of 6 mgCAF/kgBM induced clinically noticeable improvements in FGBTotal results, RTime and pre-exercise motor time. Nevertheless, there were no significant differences between any CAF doses and PLA in FGBTotal, HRmax, HRmean, RPE, pre/post-exercise RTime, PStab variables or pyruvate concentrations. Lactate concentration was higher (p < 0.05) before and after exercise in all CAF doses than in PLA. There was no effect of CYP1A2 or ADORA2A SNPs on performance. CONCLUSIONS: The dose-dependent effect of CAF supplementation appears to be limited to statistically nonsignificant but clinically considered changes on specific performance, RTime, PStab, RPE or HR. However, regarding practical CAF-induced performance implications in CrossFit/HIFT, 6 mgCAF/kgBM may be supposed as the most rational supplementation strategy.

• MeSH
• cytochrom P-450 CYP1A2 MeSH
• dvojitá slepá metoda MeSH
• klinické křížové studie MeSH
• kofein * farmakologie   MeSH
• kyselina mléčná MeSH
• lidé MeSH
• polyestery MeSH
• potravní doplňky MeSH
• reakční čas MeSH
• sportovní výkon * fyziologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• randomizované kontrolované studie MeSH

INTRO: The purpose of this study was to investigate the effects of quiet eye training (QET) on inhibitory control, visuospatial working memory (WM), and tonic attention in children with attention-deficit hyperactivity disorder (ADHD). METHODS: Forty-eight children with ADHD aged 9-12 years were randomly assigned to QET and control (CON) groups. The QET group practiced targeted hand-eye tasks within a QET protocol developed to optimize controlled attention and gaze through eye fixations. We used the go/no-go (GNG) test, the Corsi test, and the reaction test of alertness (RTA) to verify the effects of QET on inhibition control, WM, and tonic attention. RESULTS: QET group showed significantly shorter reaction times, a higher number of correct responses, and a lower number of omissions in the GNG inhibition test after QET as compared to the pre-measurements, whereas the CON group did not demonstrate significant changes in this test. The measures of WM (Corsi test) and tonic attention (RTA) did not change significantly with the QET-based intervention. CONCLUSION: The study demonstrated that the QET protocol, which includes instructions and a video demonstration to optimize eye fixation on a target during aiming tasks, is acceptable and usable for children with ADHD. Overall, a short-term, 5-week visuomotor training intervention based on the quiet eye paradigm was shown to be effective in improving inhibitory control and focused visual attention, but not visuospatial WM and intrinsic attention in 9-12-year-old children with inattentive or combined ADHD.

• MeSH
• dítě MeSH
• dvojitá slepá metoda MeSH
• hyperkinetická porucha * terapie   MeSH
• kognice MeSH
• krátkodobá paměť * fyziologie   MeSH
• lidé MeSH
• oční fixace MeSH
• reakční čas MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• randomizované kontrolované studie MeSH

Sympathetic nervous system (SNS) undergoes a prolonged period of fetal and neonatal development and maturation during which is vulnerable to a variety of influences (e.g. painful experiences). Thus, we aimed to evaluate SNS activity at rest and in response to stressful stimulus (pain) within the earliest postnatal life in healthy term neonates using electrodermal activity (EDA) measures. In twenty eutrophic healthy term neonates EDA was recorded within the first two hours after birth (measurement 1 - M1) and 72 h after birth (measurement 2 - M2) at rest and in response to pain (M1 - intramuscular K vitamin administration; M2 - heel stick). Evaluated parameters were skin conductance level (SCL), non-specific skin conductance responses (NS.SCRs), skin SCL 10 s before pain stimulus (SCL_10 before pain), skin conductance response (SCR) peak after pain stimulus, SCL 10 s after pain stimulus (SCL_10 after pain), SCR magnitude, latency, SCR rise/decline time, SCR half recovery time. SCL was significantly decreased at rest during M2 compared to M1 (p=0.010). SCL_10 before pain, SCR peak after pain, and SCL_10 after pain stimulus were significantly decreased in M2 compared to M1 (p=0.014, p=0.020, p=0.011, respectively). SCL was significantly decreased and NS.SCRs were significantly higher in the recovery period after the pain stimulus during M2 compared to M1 (p=0.015, p=0.032, respectively). Our results indicate EDA parameters sensitive to detect sympathetic changes during the earliest postnatal life reflecting its potential in early diagnosis of the autonomic maturation - linked pathological states in neonates.

• MeSH
• autonomní nervový systém MeSH
• bolest diagnóza   MeSH
• galvanická kožní odpověď * MeSH
• lidé MeSH
• novorozenec MeSH
• reakční čas MeSH
• sympatický nervový systém * fyziologie   MeSH
• Check Tag
• lidé MeSH
• novorozenec MeSH
• Publikační typ
• časopisecké články MeSH

Predmetom štúdie bolo overiť vplyv koncentrácie na rýchlosť rozhodovania a agility v motorickej úlohe. Koncentrácia bola simulovaná prostredníctvom vzostupného alternatívneho časového limitu (+1, +2s). Objektom skúmania bola skupina 26 aktívnych športovcov (n = 26, ̄x = 180,62cm; ̄x = 73,46kg; dec.vek ̄x = 20,12 r.), z toho 15 mužov a 11 žien. Vyhodnocovaný bol priemerný čas na jednotlivý stimul a celkový čas (t = 0,01s). Hodnotenie významnosti rozdielov podľa dĺžky koncentrácie nepotvrdilo signifikantné rozdiely v rýchlosti rozhodovania a agility v priemernom čase reakcie u mužov Sig.= 0,603 - Sig = 0,973 ; p > α; žien [Sig.= 0,062 - Sig = 0,085 ; p > α]; ani v celkovom čase simulovanej motorickej úlohy [muži; Sig.= 0,284 - Sig = 0,887; p > α]; ženy [Sig.= 0,082 - Sig = 0,772; p > α]. Konštatujeme, že vplyv koncentrácie na rýchlosť rozhodovania a agility nebol preukázaný.

The subject of the study was to verify the influence of concentration on decision-making speed and agility in a motor task. The concentration was simulated through an ascending alternative time limit (+1, +2s). The object of the investigation was a group of 26 active athletes (n = 26, 180.62 cm; 20.12 years old), of which 15 were men and 11 were women. The average time per individual stimulus and the total time (t = 0.01s) were evaluated. The evaluation of the significance of differences according to the length of concentration did not confirm significant differences in decision-making speed and agility in the average reaction time in men [Sig.= 0.603 - Sig = 0.973; p > α]; of women [Sig.= 0.062 - Sig = 0.085; p > α]; nor in the total time of the simulated motor task men; [Sig.= 0.284 - Sig = 0.887; p > α]; women [Sig.= 0.082 - Sig = 0.772 ; p > α]. We note that the influence of concentration on decision-making speed and agility has not been proven.

• Klíčová slova
• rozhodovací funkce, koncentrace,
• MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• pozornost * MeSH
• reakční čas MeSH
• rozhodování * MeSH
• sportovci MeSH
• výzkum MeSH
• Check Tag
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH

The vertex has been used as a suitable control stimulation site in repetitive transcranial magnetic stimulation studies. The objectives of this study are (1) to assess cognitive performance (CP) after theta burst stimulation (TBS); (2) to evaluate whether clinically relevant cortical areas might be reached by vertex stimulation and how that might influence CP. Twenty young healthy subjects performed a cognitive task prior to and immediately after intermittent TBS (iTBS) and continuous TBS (cTBS) of two active cortical stimulation sites and the vertex. We used the Wilcoxon signed-rank test to compare the pre- and post-stimulation reaction times (RTs) and a mixed ANOVA analysis to evaluate the effect of the stimulation on changes in RTs. A three-dimensional finite-element model (FEM) was used to calculate the vertex TBS-induced electrical field (E-field) in the adjacent regions of interest (ROIs). Correlation analyses were performed between E-fields in the ROIs and cognitive outcomes. We found a significant effect only of the stimulation time factor (F (1,12) = 65.37, p < 0.001) on RT shortening, with no superiority of the active site stimulation compared to the vertex stimulation. In 73.5% of vertex TBS sessions, a significant E-field was induced in at least one ROI. We found a negative association between the magnitude of the iTBS-induced E-fields and RT changes (R = - 0.54, p = 0.04). TBS protocols may lead to changes in CP when applied over the craniometrically targeted vertex. We therefore suggest not using a conventional approach as a vertex targeting method.

• MeSH
• hlava * MeSH
• lidé MeSH
• reakční čas MeSH
• theta rytmus EEG MeSH
• transkraniální magnetická stimulace * metody   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

A startling auditory stimulus (SAS) induces a reflex response involving, among other reactions, a strong contraction of the orbicularis oculi muscle (OOc) and subsequent eye closure. A SAS also induces the StartReact effect, a significant shortening of reaction time in subjects ready for task execution. We examined the obvious conflict appearing when a StartReact paradigm requires participants with eyes closed to open their eyes to look for a visual target. We recorded OOc EMG activity and eyelid movements in healthy volunteers who were instructed to open their eyes at perception of a somatosensory imperative stimulus (IS) and locate the position of a Libet's clock's hand shown on a computer screen at 80 cm distance. In 6 out of 20 trials, we delivered a SAS simultaneously with the IS. The main outcome measures were reaction time at onset of eyelid movement and the time gap (TG) separating subjective assessment of the clock's hand position from real IS issuing. Control experiments included reaction time to eye closing and target location with eyes open to the same IS. Reaction time was significantly faster in SAS than in noSAS trials and slower for eye opening than for eye closing in both conditions. In the eye-opening task, TG was significantly shorter in SAS with respect to noSAS trials, despite the presence of the SAS-related burst in the OOc before EMG cessation. Our results indicate that the StartReact effect speeds up eye opening and location of a target in the visual field despite the startle reaction opposing the task.

• MeSH
• dospělí MeSH
• elektromyografie MeSH
• fyzikální stimulace MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• obličejové svaly fyziologie   MeSH
• oční víčka fyziologie   MeSH
• psychomotorický výkon fyziologie   MeSH
• reakční čas fyziologie   MeSH
• senioři MeSH
• sluchová percepce fyziologie   MeSH
• úleková reakce fyziologie   MeSH
• zraková percepce fyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

PURPOSE: Simulation of indirect damage originating from the attack of free radical species produced by ionizing radiation on biological molecules based on the independent pair approximation is investigated in this work. In addition, a new approach, relying on the independent pair approximation that is at the origin of the independent reaction time (IRT) method, is proposed in the chemical stage of Geant4-DNA. METHODS: This new approach has been designed to respect the current Geant4-DNA chemistry framework while proposing a variant IRT method. Based on the synchronous algorithm, this implementation allows us to access the information concerning the position of radicals and may make it more convenient for biological damage simulations. Estimates of the evolution of free species as well as biological hits in a segment of DNA chromatin fiber in Geant4-DNA were compared for the dynamic time step approach of the step-by-step (SBS) method, currently used in Geant4-DNA, and this newly implemented IRT. RESULTS: Results show a gain in computation time of a factor of 30 for high LET particle tracks with a better than 10% agreement on the number of DNA hits between the value obtained with the IRT method as implemented in this work and the SBS method currently available in Geant4-DNA. CONCLUSION: Offering in Geant4-DNA more efficient methods for the chemical step based on the IRT method is a task in progress. For the calculation of biological damage, information on the position of chemical species is a crucial point. This can be achieved using the method presented in this paper.

• MeSH
• chromatin genetika   MeSH
• DNA * genetika   MeSH
• metoda Monte Carlo MeSH
• poškození DNA * MeSH
• reakční čas MeSH
• Publikační typ
• časopisecké články MeSH