Working memory (WM) is essential for the temporary storage and processing of information required for complex cognitive tasks and relies on neuronal theta and gamma oscillations. Given the limited capacity of WM, researchers have investigated various methods to improve it, including transcranial alternating current stimulation (tACS), which modulates brain activity at specific frequencies. One particularly promising approach is theta-gamma peak-coupled-tACS (TGCp-tACS), which simulates the natural interaction between theta and gamma oscillations that occurs during cognitive control in the brain. The aim of this study was to improve WM in healthy young adults with TGCp-tACS, focusing on both behavioral and neurophysiological outcomes. Thirty-one participants completed five WM tasks under both sham and verum stimulation conditions. Electroencephalography (EEG) recordings before and after stimulation showed that TGCp-tACS increased power spectral density (PSD) in the high-gamma region at the stimulation site, while PSD decreased in the theta and delta regions throughout the cortex. From a behavioral perspective, although no significant changes were observed in most tasks, there was a significant improvement in accuracy in the 14-item Sternberg task, indicating an improvement in phonological WM. In conclusion, TGCp-tACS has the potential to promote and improve the phonological component of WM. To fully realize the cognitive benefits, further research is needed to refine the stimulation parameters and account for individual differences, such as baseline cognitive status and hormonal factors.

• MeSH
• chování fyziologie   MeSH
• dospělí MeSH
• elektrická stimulace MeSH
• elektroencefalografie MeSH
• gama rytmus EEG fyziologie   MeSH
• krátkodobá paměť * fyziologie   MeSH
• lidé MeSH
• mladý dospělý MeSH
• přímá transkraniální stimulace mozku * metody   MeSH
• theta rytmus EEG fyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

There is accumulating evidence that training on working memory (WM) generalizes to other nontrained domains, and there are reports of transfer effects extending as far as to measures of fluid intelligence. Although there have been several demonstrations of such transfer effects in young adults and children, they have been difficult to demonstrate in older adults. In this study, we investigated the generalizing effects of an adaptive WM intervention on nontrained measures of WM and visuospatial skills. We randomly assigned healthy older adults to train on a verbal n-back task over the course of a month for either 10 or 20 sessions. Their performance change was compared with that of a control group. Our results revealed reliable group effects in nontrained standard clinical measures of WM and visuospatial skills in that both training groups outperformed the control group. We also observed a dose-response effect, that is, a positive relationship between training frequency and the gain in visuospatial skills; this finding was further confirmed by a positive correlation between training improvement and transfer. The improvements in visuospatial skills emerged even though the intervention was restricted to the verbal domain. Our work has important implications in that our data provide further evidence for plasticity of cognitive functions in old age.

• MeSH
• krátkodobá paměť * MeSH
• lidé MeSH
• praxe (psychologie) MeSH
• přenos učení (psychologie) * MeSH
• psychologické testy MeSH
• senioři MeSH
• stárnutí psychologie   MeSH
• vnímání prostoru * MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• randomizované kontrolované studie MeSH
• Research Support, U.S. Gov't, Non-P.H.S. 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

We sought to determine if Parkinson's disease (PD) with mild cognitive impairment (MCI) is associated with a greater SERIAL-ORDER (mental manipulation) than ANY-ORDER (auditory span, storage) deficit in working memory (WM). We investigated WM combining neuropsychological measures with the study of brain functional connectivity. A cohort of 160 patients with idiopathic PD, classified as PD-MCI (n = 87) or PD with normal cognition (PD-NC; n = 73), and 70 matched healthy controls were studied. Verbal WM was assessed with the Backward Digit Span Task (BDT; Lamar et al., 2007, Neuropsychologia, 45, 245), measuring SERIAL-ORDER and ANY-ORDER recall. Resting-state MRI data were collected for 15 PD-MCI, 15 PD-NC and 30 controls. Hypothesis-driven seed-based functional connectivity of the dorsolateral prefrontal cortex (DLPFC) was compared between the three groups and correlated with BDT performance. We found the main effect of the test (impairment in SERIAL ORDER > ANY ORDER) and group ((NC = PD-NC) > PD-MCI) in BDT performance that was even more pronounced in SERIAL ORDER when controlling for ANY ORDER variability but not vice versa. Furthermore, PD-MCI compared to other groups were characterized by the functional disconnection between the bilateral DLPFC and the cerebellum. In functional correlations, DLPFC connectivity was positively related to both SERIAL- and ANY-ORDER performance. In conclusion, PD-MCI patients evidenced greater SERIAL-ORDER (manipulation and cognitive control) than ANY-ORDER (storage) working memory impairment than PD-NC and controls with a disrupted DLPFC resting-state connectivity that was also related to the verbal WM performance.

• MeSH
• kognice MeSH
• kognitivní dysfunkce * diagnostické zobrazování   etiologie   MeSH
• krátkodobá paměť MeSH
• lidé MeSH
• neuropsychologické testy MeSH
• neurozobrazování MeSH
• Parkinsonova nemoc * komplikace   diagnostické zobrazování   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem 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

Cíl. Funkční zobrazování magnetickou rezonancí (fMRI) bylo použito k mapování aktivních míst mozkové kůry během testu vizuální pracovní paměti u skupiny osmi zdravých dobrovolníků a u dvou pacientů - u pacientky s kavernomem v oblasti pravého sluchového kortexu a u pacienta s dysplazií pravé frontální oblasti. Metoda. Proces zapamatování promítaných karet byl použit ke stimulaci vizuální pracovní paměti. Aktivace spojené s vizuální pracovní pamětí byly porovnány s aktivacemi testu verbální fluence. Výsledky. Funkční mapy ukázaly oboustranné aktivace frontálních laloků a parieto-okcipitálních oblastí. Závěr. Oproti testu verbální fluence byla nalezena výraznější aktivace v pravém frontálním laloku.

Aim. Functional magnetic resonance imaging (fMRI) was used to map active areas of the brain during visual working memory processing in a group of 8 healthy volunteers and two patients - one patient with a cavernoma in the right auditory cortex and one patient with dysplasia in the right frontal lobes. Method. The process of memorizing projected playing cards was used to stimulate visual working memory (VWM) areas. In order to compare visual WM activation with speech related areas, we used the verbal fluency test. Results. Functional maps showed bilateral activation in the frontal lobes and in the parietal-occipital lobes. Conclusion. In comparison with verbal fluency (VF) test significant activations was found in the right frontal lobe.

• MeSH
• čelní lalok patofyziologie   patologie   MeSH
• financování organizované MeSH
• lidé MeSH
• magnetická rezonanční tomografie metody   využití   MeSH
• mapování mozku metody   přístrojové vybavení   MeSH
• mozková kůra patofyziologie   patologie   MeSH
• nemoci mozku komplikace   patofyziologie   patologie   MeSH
• paměť fyziologie   MeSH
• verbální chování fyziologie   MeSH
• Check Tag
• lidé MeSH

l-Tyrosine (TYR), the precursor of dopamine (DA), has been shown to enhance facets of cognitive control in situations with high cognitive demands. However some previous outcomes were mixed: some studies reported significant improvements, while other did not. Given that TYR increases DA level in the brain, we investigated, in a double-blind, randomized, placebo-controlled design, whether the C957T genotypes of a functional synonymous polymorphism in the human dopamine D2 receptor (DRD2) gene (rs6277) contribute to individual differences in the reactivity to TYR administration and whether this factor predicts the magnitude of TYR-induced performance differences on inhibiting behavioral responses in a stop-signal task and working memory (WM) updating in a N-back task. Our findings show that T/T homozygotes (i.e., individuals potentially associated with lower striatal DA level) showed larger beneficial effects of TYR supplementation than C/C homozygotes (i.e., individuals potentially associated with higher striatal DA level), suggesting that genetically determined differences in DA function may explain inter-individual differences in response to TYR supplementation. These findings reinforce the idea that genetic predisposition modulates the effect of TYR in its role as cognitive enhancer.

• MeSH
• dvojitá slepá metoda MeSH
• farmakogenetika MeSH
• genotyp * MeSH
• individualita MeSH
• inhibice (psychologie) * MeSH
• jednonukleotidový polymorfismus MeSH
• krátkodobá paměť účinky léků   fyziologie   MeSH
• lidé MeSH
• mladý dospělý MeSH
• neuropsychologické testy MeSH
• receptory dopaminu D2 genetika   MeSH
• tyrosin farmakologie   MeSH
• Check Tag
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• randomizované kontrolované studie MeSH

Working memory (WM) is the active retention and processing of information over a few seconds and is considered an essential component of cognitive function. The reduced WM capacity is a common feature in many diseases, such as schizophrenia, attention deficit hyperactivity disorder (ADHD), mild cognitive impairment (MCI), and Alzheimer's disease (AD). The theta-gamma neural code is an essential component of memory representations in the multi-item WM. A large body of studies have examined the association between cross-frequency coupling (CFC) across the cerebral cortices and WM performance; electrophysiological data together with the behavioral results showed the associations between CFC and WM performance. The oscillatory entrainment (sensory, non-invasive electrical/magnetic, and invasive electrical) remains the key method to investigate the causal relationship between CFC and WM. The frequency-tuned non-invasive brain stimulation is a promising way to improve WM performance in healthy and non-healthy patients with cognitive impairment. The WM performance is sensitive to the phase and rhythm of externally applied stimulations. CFC-transcranial-alternating current stimulation (CFC-tACS) is a recent approach in neuroscience that could alter cognitive outcomes. The studies that investigated (1) the association between CFC and WM and (2) the brain stimulation protocols that enhanced WM through modulating CFC by the means of the non-invasive brain stimulation techniques have been included in this review. In principle, this review can guide the researchers to identify the most prominent form of CFC associated with WM processing (e.g., theta/gamma phase-amplitude coupling), and to define the previously published studies that manipulate endogenous CFC externally to improve WM. This in turn will pave the path for future studies aimed at investigating the CFC-tACS effect on WM. The CFC-tACS protocols need to be thoroughly studied before they can be considered as therapeutic tools in patients with WM deficits.

• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Several studies suggest that EEG parameters, reflecting top-down processes in the brain, may predict cognitive performance, e.g. short-term memory (STM) capacity. According to Lisman and Idiart's model, STM capacity is predicted by theta and gamma EEG waves and their ratio. This model suggests that the more periods of gamma band waves fit into one period of theta band waves, the more information can be stored. We replicated the study by Kaminski et al. (2011), which recorded spontaneous EEG activity and measured verbal STM capacity with a modified digit span task from the Wechsler battery. Our study included more subjects and two EEG recording sessions. We discuss the possible limits of EEG correlates of STM capacity as EEG parameters were not stable across the two measurements and no correlation was found between the theta/gamma ratio and performance in the digit span task.

• MeSH
• biologické modely MeSH
• dospělí MeSH
• gama rytmus EEG fyziologie   MeSH
• krátkodobá paměť fyziologie   MeSH
• lidé MeSH
• mladý dospělý MeSH
• psychomotorický výkon fyziologie   MeSH
• theta rytmus EEG fyziologie   MeSH
• Wechslerovy škály MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH

Aging populations face significant cognitive challenges, particularly in working memory (WM). Transcranial alternating current stimulation (tACS) offer promising avenues for cognitive enhancement, especially when inspired by brain physiology. This study (NCT04986787) explores the effect of multifocal tACS on WM performance in healthy older adults, focusing on fronto-parietal network modulation. Individualized physiology-inspired tACS applied to the fronto-parietal network was investigated in two blinded cross-over experiments. The first experiment involved monofocal/bifocal theta-tACS to the fronto-parietal network, while in the second experiment cross-frequency theta-gamma interactions between these regions were explored. Participants have done online WM tasks under the stimulation conditions. Network connectivity was assessed via rs-fMRI and multichannel electroencephalography. Prefrontal monofocal theta tACS modestly improved WM accuracy over sham (d = 0.30). Fronto-parietal stimulation enhanced WM task processing speed, with the strongest effects for bifocal in-phase theta tACS (d = 0.41). Cross-frequency stimulations modestly boosted processing speed with or without impairing task accuracy depending on the stimulation protocol. This research adds to the understanding of physiology-inspired brain stimulation for cognitive enhancement in older subjects.

• Publikační typ
• časopisecké články MeSH