Working memory
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V současnosti se paměť chápe jako modulární systém. Každý modul slouží odlišné funkci a má odlišnou anatomickou vazbu. Činnost modulů je do značné míry nezávislá. Existuje krátkodobá (pracovní) paměť a dlouhodobá explicitní a implicitní paměť. Explicitní (deklarativní) paměť (epizodická i sémantická) je vědomá, poškozuje ji léze mediálních temporálních struktur. Amnézie je porucha explicitní paměti. Implicitní paměť má několik podob (procedurální, priming, klasické a emoční podmiňování, neasociativní učení), které vědomé pozornosti přístupné nejsou. Zvláštní kapitolou je psychogenní amnézie.
Human memory is now viewed as a modular system. Each module serves different function, being supported by different anatomical structures. These systems operate independently. Working memory is a transient memory that temporarily stores and maintains internal representations and controls their processing. Long-term explicit memory is asociated with conscious awareness. Amnesia is a disorder of explicit memory. There are several types of implicit memory: procedural (motor skills), priming, classical and emotional conditioning, and non-associative learning. They are not consciously accessible. Psychogenic amnesia and false memory syndrome are also discussed.
Kyselina domoová, aminokyselina produkovaná některými mikroskopickými řasami mořského fytoplanktonu, je příčinou toxicity některých mořských živočichů, zejména měkkýšů. Jejich konzumace vyvolá neobvyklou otravu doprovázenou v mnoha případech trvalou ztrátou krátkodobé paměti. Jsou uvedeny základní informace o tomto zajímavém excitotoxinu.
Domoic acid, an amino acid produced by some microalgae of the sea phytoplankton, can cause the toxicity of some sea animals, especially shellfish. Their consumption may lead to unusuall poisoning accompanied in many cases by permanent short-term memory loss. The article brings basic information about this interesting excitotoxin.
The way the human brain represents speech in memory is still unknown. An obvious characteristic of speech is its evolvement over time. During speech processing, neural oscillations are modulated by the temporal properties of the acoustic speech signal, but also acquired knowledge on the temporal structure of language influences speech perception-related brain activity. This suggests that speech could be represented in the temporal domain, a form of representation that the brain also uses to encode autobiographic memories. Empirical evidence for such a memory code is lacking. We investigated the nature of speech memory representations using direct cortical recordings in the left perisylvian cortex during delayed sentence reproduction in female and male patients undergoing awake tumor surgery. Our results reveal that the brain endogenously represents speech in the temporal domain. Temporal pattern similarity analyses revealed that the phase of frontotemporal low-frequency oscillations, primarily in the beta range, represents sentence identity in working memory. The positive relationship between beta power during working memory and task performance suggests that working memory representations benefit from increased phase separation.SIGNIFICANCE STATEMENT Memory is an endogenous source of information based on experience. While neural oscillations encode autobiographic memories in the temporal domain, little is known on their contribution to memory representations of human speech. Our electrocortical recordings in participants who maintain sentences in memory identify the phase of left frontotemporal beta oscillations as the most prominent information carrier of sentence identity. These observations provide evidence for a theoretical model on speech memory representations and explain why interfering with beta oscillations in the left inferior frontal cortex diminishes verbal working memory capacity. The lack of sentence identity coding at the syllabic rate suggests that sentences are represented in memory in a more abstract form compared with speech coding during speech perception and production.
- MeSH
- dospělí MeSH
- elektrokortikografie MeSH
- krátkodobá paměť fyziologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- mozek fyziologie MeSH
- percepce řeči fyziologie MeSH
- řeč fyziologie 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
- práce podpořená grantem MeSH
- MeSH
- finanční podpora výzkumu jako téma MeSH
- krátkodobá paměť MeSH
- lidé MeSH
- psychologické modely MeSH
- vědomí MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
- srovnávací studie MeSH
OBJECTIVES: Autism spectrum disorder (ASD) is associated with repetitive and stereotyped behaviour, suggesting that cognitive flexibility may be deficient in ASD. A central, yet not examined aspect to understand possible deficits in flexible behaviour in ASD relates (i) to the role of working memory and (ii) to neurophysiological mechanisms underlying behavioural modulations. METHODS: We analysed behavioural and neurophysiological (EEG) correlates of cognitive flexibility using a task-switching paradigm with and without working memory load in adolescents with ASD and typically developing controls (TD). RESULTS: Adolescents with ASD versus TD show similar performance in task switching with no memory load, indicating that 'pure' cognitive flexibility is not in deficit in adolescent ASD. However performance during task repetition decreases with increasing memory load. Neurophysiological data reflect the pattern of behavioural effects, showing modulations in P2 and P3 event-related potentials. CONCLUSIONS: Working memory demands affect repetitive behaviour while processes of cognitive flexibility are unaffected. Effects emerge due to deficits in preparatory attentional processes and deficits in task rule activation, organisation and implementation of task sets when repetitive behaviour is concerned. It may be speculated that the habitual response mode in ASD (i.e. repetitive behaviour) is particularly vulnerable to additional demands on executive control processes.
- MeSH
- dítě MeSH
- elektroencefalografie MeSH
- exekutivní funkce MeSH
- kognice * MeSH
- krátkodobá paměť * MeSH
- lidé MeSH
- mladiství MeSH
- neuropsychologické testy MeSH
- poruchy autistického spektra patofyziologie psychologie MeSH
- pozornost MeSH
- psychomotorický výkon MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- mladiství MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Previous research has shown mixed results for the ability of working memory training to improve fluid intelligence. The aims of this study were first to replicate these improvements, and then to explore the moderating role of Personality Systems Interaction (PSI) personality factors. By using three different training methods and an active-contact control group, we examined the effects of 25 days of cognitive training on 142 participants. After examining our results in context of PSI theory, we found that different training methods yielded different IQ gains in participants, depending on their personality styles. In addition, these correlations suggested a meaningful pattern, indicating that PSI theory may be able to account for the different outcomes of cognitive training studies. Our findings may facilitate tailor-made cognitive training interventions in the future, and can contribute to explaining the mechanisms underlying the far transfer of working memory training to fluid intelligence.
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
