• MeSH
• Emotions MeSH
• Ethanol MeSH
• Stress, Physiological MeSH
• Morphine MeSH
• Mice MeSH
• Memory drug effects   MeSH
• Check Tag
• Mice MeSH

• MeSH
• Emotions MeSH
• Ethanol MeSH
• Stress, Physiological MeSH
• Morphine MeSH
• Mice MeSH
• Memory drug effects   MeSH
• Check Tag
• Mice MeSH

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.

• MeSH
• Amnesia MeSH
• Brain MeSH
• Memory classification   MeSH
• Publication type
• Review MeSH

With an increasingly aging global population, the incidence of neurological diseases such as dementia is set to increase to unmanageable levels, yet there are currently only symptomatic therapies available for treatment. The mechanisms underlying the development of some forms of dementia, such as Alzheimer's disease (AD), are not yet completely elucidated with several competing hypotheses existing. During the closure of the critical period in the brain, significant compositional changes occur to the neural extracellular matrix (ECM). Specifically, condensed mesh-like structures called perineuronal nets (PNNs) form around subsets of neurons and have a profound effect on axonal growth and limit neuronal plasticity. These PNNs act as a morphological checkpoint and can influence memory and cognition. Manipulating these important ECM structures may provide the key to reactivating plasticity and restoring memory, both of which are severely impaired in AD and other associated neurological diseases. This review explores the current understanding of how PNNs are manipulated and examines potential new methods for PNN modulation. LINKED ARTICLES: This article is part of a themed section on Therapeutics for Dementia and Alzheimer's Disease: New Directions for Precision Medicine. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.18/issuetoc.

• MeSH
• Extracellular Matrix physiology   MeSH
• Humans MeSH
• Neurons physiology   MeSH
• Neuronal Plasticity * MeSH
• Memory * MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH

Many cognitive functions, including working memory, are processed within large-scale brain networks. We targeted the right frontoparietal network (FPN) with one session of transcranial direct current stimulation (tDCS) in an attempt to modulate the cognitive speed of a visual working memory task (WMT) in 27 young healthy subjects using a double-blind crossover design. We further explored the neural underpinnings of induced changes by performing resting-state fMRI prior to and immediately after each stimulation session with the main focus on the interaction between a task-positive FPN and a task-negative default mode network (DMN). Twenty minutes of 2 mA anodal tDCS was superior to sham stimulation in terms of cognitive speed manipulation of a subtask with processing of objects and tools in unconventional views (i.e., the higher cognitive load subtask of the offline WMT). This result was linked to the magnitude of resting-state functional connectivity decreases between the stimulated FPN seed and DMN seeds. We provide the first evidence for the action reappraisal mechanism of object and tool processing. Modulation of cognitive speed of the task by tDCS was reflected by FPN-DMN cross-talk changes.

• MeSH
• Frontal Lobe diagnostic imaging   physiopathology   MeSH
• Adult MeSH
• Double-Blind Method MeSH
• Cross-Over Studies MeSH
• Memory, Short-Term physiology   MeSH
• Humans MeSH
• Magnetic Resonance Imaging MeSH
• Adolescent MeSH
• Young Adult MeSH
• Neuropsychological Tests MeSH
• Transcranial Direct Current Stimulation MeSH
• Reaction Time physiology   MeSH
• Parietal Lobe diagnostic imaging   physiopathology   MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Inhibitory control processes are known to be modulated by working memory demands. However, the neurobiological mechanisms behind these modulations are inconclusive. One important system to consider in this regard is the locus coeruleus (LC) norepinephrine (NE) system. In the current study the role of the LC-NE system by means of pupil diameter recordings that are integrated with neurophysiological (EEG) and source localization data were examined. A combined mental-rotation Go/Nogo task was used. The results show that increases in working memory load complicate response inhibition processes. On a neurophysiological level these effects were reflected by specific modulations in event-related potentials (ERPs) reflecting motor inhibition processes (i.e., Nogo-P3). Attentional selection processes (reflected by the P1 and N1) as well as pre-motor inhibition or conflict monitoring processes (reflected by the Nogo-N2) were not affected. Activity of the LC-NE systems, as indexed by the pupil diameter data, predicted neurophysiological processes selectively in the Nogo-P3 time range. Source localization analyses suggest that this modulation occurs in the right middle and inferior frontal gyrus. The study provides evidence that the LC-NE system is an important neurobiological system modulating the effects of working memory load on response inhibition processes. More specifically, it modulates a subset of dissociable cognitive processes that are related to prefrontal cortical regions. Hum Brain Mapp 38:68-81, 2017. © 2016 Wiley Periodicals, Inc.

• MeSH
• Analysis of Variance MeSH
• Adult MeSH
• Electroencephalography MeSH
• Evoked Potentials physiology   MeSH
• Inhibition, Psychological * MeSH
• Memory, Short-Term physiology   MeSH
• Humans MeSH
• Brain Mapping * MeSH
• Adolescent MeSH
• Young Adult MeSH
• Neuropsychological Tests MeSH
• Pupil physiology   MeSH
• Reaction Time physiology   MeSH
• Decision Making physiology   MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

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
• Adult MeSH
• Electrocorticography MeSH
• Memory, Short-Term physiology   MeSH
• Middle Aged MeSH
• Humans MeSH
• Young Adult MeSH
• Brain physiology   MeSH
• Speech Perception physiology   MeSH
• Speech physiology   MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Young Adult MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Direct electrical stimulation of the brain has emerged as a powerful treatment for multiple neurological diseases, and as a potential technique to enhance human cognition. Despite its application in a range of brain disorders, it remains unclear how stimulation of discrete brain areas affects memory performance and the underlying electrophysiological activities. Here, we investigated the effect of direct electrical stimulation in four brain regions known to support declarative memory: hippocampus (HP), parahippocampal region (PH) neocortex, prefrontal cortex (PF), and lateral temporal cortex (TC). Intracranial EEG recordings with stimulation were collected from 22 patients during performance of verbal memory tasks. We found that high γ (62-118 Hz) activity induced by word presentation was modulated by electrical stimulation. This modulatory effect was greatest for trials with "poor" memory encoding. The high γ modulation correlated with the behavioral effect of stimulation in a given brain region: it was negative, i.e., the induced high γ activity was decreased, in the regions where stimulation decreased memory performance, and positive in the lateral TC where memory enhancement was observed. Our results suggest that the effect of electrical stimulation on high γ activity induced by word presentation may be a useful biomarker for mapping memory networks and guiding therapeutic brain stimulation.

• MeSH
• Adult MeSH
• Electric Stimulation * MeSH
• Electrocorticography * MeSH
• Gamma Rhythm physiology   MeSH
• Middle Aged MeSH
• Humans MeSH
• Young Adult MeSH
• Cerebral Cortex physiology   MeSH
• Memory physiology   MeSH
• Drug Resistant Epilepsy physiopathology   MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Young Adult MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Multicenter Study MeSH
• Research Support, Non-U.S. Gov't MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH

• MeSH
• Neuropeptides physiology   classification   MeSH
• Memory physiology   MeSH
• Synapses physiology   MeSH
• Learning physiology   MeSH
• Publication type
• Review MeSH

Arousing events influence retrieval success, with a number of studies supporting a context-dependent effect of arousal on episodic memory retrieval. An improvement in speed and accuracy of episodic memories is observed when negative arousal is attached to them. In contrast, enhancing effects of negative arousal have not been reported to improve semantic memory retrieval. Episodic and semantic memory are highly interactive and yet differ based on their embedded contextual content. Although differences in brain activity exist between episodic and semantic memory, the two types of memory retrieval are part of a common long-term memory system. Considering the shared processes between episodic and semantic memory, the objectives of the current study were twofold: i) to examine, employing a novel paradigm, whether performance on episodic and semantic memory retrieval would be influenced differently by varying levels of arousal, between negative and neutral valence; and ii) to explore the neural patterns underlying these processes. Forty-seven healthy young adults were recruited and completed the experiment in the MRI scanner. The results demonstrated a negative arousal effect on the brain circuitry subserving both memory conditions as well as on behavioural performance, as indicated by better accuracy and faster reaction times. The study provides an insight into the role of negative arousal in memory processes and contributes to our understanding of the interplay between cognitive and emotional factors in memory modulation. Our work also highlights the highly interactive nature of episodic and semantic memory, and emphasises the importance in understanding how negative arousal interacts with the contextual content of a memory, on a behavioural and neurofunctional level.

• MeSH
• Arousal MeSH
• Emotions MeSH
• Memory, Episodic * MeSH
• Humans MeSH
• Brain Mapping MeSH
• Young Adult MeSH
• Brain * diagnostic imaging   MeSH
• Mental Recall MeSH
• Semantics MeSH
• Check Tag
• Humans MeSH
• Young Adult MeSH
• Publication type
• Journal Article MeSH