scholarly journals A neural network account of memory replay and knowledge consolidation

2021 ◽  
Author(s):  
Daniel N Barry ◽  
Bradley C Love
Keyword(s):  
Neural Network ◽  
Network Performance ◽  
Occipital Cortex ◽  
Long Term Memory ◽  
Visual Stream ◽  
Functional Roles ◽  
Early Visual Cortex ◽  
Past Experiences ◽  
The Brain

Replay can consolidate memories by offline neural reactivation related to past experiences. Category knowledge is learned across multiple experiences and subsequently generalised to new situations. This ability to generalise is promoted by offline consolidation and replay during rest and sleep. However, aspects of replay are difficult to determine from neuroimaging studies alone. Here, we provide a comprehensive account of how category replay may work in the brain by simulating these processes in a neural network which assumed the functional roles of the human ventral visual stream and hippocampus. We showed that generative replay, akin to imagining entirely new instances of a category, facilitated generalisation to new experiences. This invites a reconsideration of the nature of replay more generally, and suggests that replay helps to prepare us for the future as much as remember the past. We simulated generative replay at different network locations finding it was most effective in later layers equivalent to the lateral occipital cortex, and less effective in layers corresponding to early visual cortex, thus drawing a distinction between the observation of replay in the brain and its relevance to consolidation. We modelled long-term memory consolidation in humans and found that category replay is most beneficial for newly acquired knowledge, at a time when generalisation is still poor, a finding which suggests replay helps us adapt to changes in our environment. Finally, we present a novel mechanism for the frequent observation that the brain selectively consolidates weaker information, and showed that a reinforcement learning process in which categories were replayed according to their contribution to network performance explains this well-documented phenomenon, thus reconceptualising replay as an active rather than passive process.

The Acute Effect of Alcohol on Various Memory Processes

2010 ◽  
Vol 24 (4) ◽  
pp. 249-252 ◽  
Author(s):  
Márk Molnár ◽  
Roland Boha ◽  
Balázs Czigler ◽  
Zsófia Anna Gaál
Keyword(s):  
Low Dose ◽  
Short Term Memory ◽  
Acute Effect ◽  
Long Term Memory ◽  
Term Memory ◽  
Memory Processes ◽  
Different Types ◽  
The Brain ◽  
Legal Consequences

This review surveys relevant and recent data of the pertinent literature regarding the acute effect of alcohol on various kinds of memory processes with special emphasis on working memory. The characteristics of different types of long-term memory (LTM) and short-term memory (STM) processes are summarized with an attempt to relate these to various structures in the brain. LTM is typically impaired by chronic alcohol intake but according to some data a single dose of ethanol may have long lasting effects if administered at a critically important age. The most commonly seen deleterious acute effect of alcohol to STM appears following large doses of ethanol in conditions of “binge drinking” causing the “blackout” phenomenon. However, with the application of various techniques and well-structured behavioral paradigms it is possible to detect, albeit occasionally, subtle changes of cognitive processes even as a result of a low dose of alcohol. These data may be important for the consideration of legal consequences of low-dose ethanol intake in conditions such as driving, etc.

scholarly journals Sotalol does not interfere with the antielectroshock action of selected second-generation antiepileptic drugs in mice

2021 ◽  
Author(s):  
Kinga K. Borowicz-Reutt ◽  
Monika Banach ◽  
Monika Rudkowska ◽  
Anna Stachniuk
Keyword(s):  
Antiepileptic Drugs ◽  
Second Generation ◽  
Antidepressant Drug ◽  
Experimental Models ◽  
Long Term Memory ◽  
Avoidance Task ◽  
Maximal Electroshock ◽  
Term Memory ◽  
The Brain

Abstract Background Due to blocking β-receptors, and potassium KCNH2 channels, sotalol may influence seizure phenomena. In the previous study, we have shown that sotalol potentiated the antielectroshock action of phenytoin and valproate in mice. Materials and methods As a continuation of previous experiments, we examined the effect of sotalol on the action of four chosen second-generation antiepileptic drugs (oxcarbazepine, lamotrigine, pregabalin, and topiramate) against the maximal electroshock in mice. Undesired effects were evaluated in the chimney test (motor impairment) and step-through passive-avoidance task (long-term memory deficits). Finally, brain concentrations of antiepileptics were determined by fluorescence polarization immunoassay, while those of sotalol by liquid chromatography–mass spectrometry. Results Sotalol at doses of up to 100 mg/kg did not affect the electroconvulsive threshold. Applied at doses of 80–100 mg/kg, sotalol did not affect the antielectroshock action of oxcarbazepine, lamotrigine, pregabalin, or topiramate. Sotalol alone and in combinations with antiepileptics impaired neither motor performance nor long-term memory. Finally, sotalol significantly decreased the brain concentrations of lamotrigine and increased those of oxcarbazepine and topiramate. Pharmacokinetic interactions, however, did not influence the final antielectroshock effects of above-mentioned drug combinations. On the other hand, the brain concentrations of sotalol were not changed by second-generation antiepileptics used in this study. Conclusion Sotalol did not reduce the antielectroshock action of four second-generation antiepileptic drugs examined in this study. Therefore, this antidepressant drug should not interfere with antiseizure effects of lamotrigine, oxcarbazepine, pregabalin, and topiramate in patients with epilepsy. To draw final conclusions, our preclinical data should still be confirmed in other experimental models and clinical conditions.

Converging Evidence That Neural Plasticity Underlies Transcranial Direct-Current Stimulation

2021 ◽  
Vol 33 (1) ◽  
pp. 146-157
Author(s):  
Chong Zhao ◽  
Geoffrey F. Woodman
Keyword(s):  
Visual Search ◽  
Direct Current ◽  
Neural Plasticity ◽  
Transcranial Direct Current Stimulation ◽  
Time Course ◽  
Memory Task ◽  
Long Term Memory ◽  
Visual Stream ◽  
Direct Current Stimulation ◽  
The Brain

It is not definitely known how direct-current stimulation causes its long-lasting effects. Here, we tested the hypothesis that the long time course of transcranial direct-current stimulation (tDCS) is because of the electrical field increasing the plasticity of the brain tissue. If this is the case, then we should see tDCS effects when humans need to encode information into long-term memory, but not at other times. We tested this hypothesis by delivering tDCS to the ventral visual stream of human participants during different tasks (i.e., recognition memory vs. visual search) and at different times during a memory task. We found that tDCS improved memory encoding, and the neural correlates thereof, but not retrieval. We also found that tDCS did not change the efficiency of information processing during visual search for a certain target object, a task that does not require the formation of new connections in the brain but instead relies on attention and object recognition mechanisms. Thus, our findings support the hypothesis that direct-current stimulation modulates brain activity by changing the underlying plasticity of the tissue.

Memristor-Based Neural Network Circuit of Long-term Memory

2021 ◽  
Author(s):  
Juntao Han ◽  
Junwei Sun ◽  
Xiao Xiao ◽  
Peng Liu
Keyword(s):  
Neural Network ◽  
Long Term Memory ◽  
Term Memory

Impairments to Consolidation, Reconsolidation, and Long-Term Memory Maintenance Lead to Memory Erasure

2020 ◽  
Vol 43 (1) ◽  
pp. 297-314 ◽  
Author(s):  
Josué Haubrich ◽  
Matteo Bernabo ◽  
Andrew G. Baker ◽  
Karim Nader
Keyword(s):  
Memory Trace ◽  
Direct Approach ◽  
Long Term Memory ◽  
Retrieval Failure ◽  
Term Memory ◽  
The Brain

An enduring problem in neuroscience is determining whether cases of amnesia result from eradication of the memory trace (storage impairment) or if the trace is present but inaccessible (retrieval impairment). The most direct approach to resolving this question is to quantify changes in the brain mechanisms of long-term memory (BM-LTM). This approach argues that if the amnesia is due to a retrieval failure, BM-LTM should remain at levels comparable to trained, unimpaired animals. Conversely, if memories are erased, BM-LTM should be reduced to resemble untrained levels. Here we review the use of BM-LTM in a number of studies that induced amnesia by targeting memory maintenance or reconsolidation. The literature strongly suggests that such amnesia is due to storage rather than retrieval impairments. We also describe the shortcomings of the purely behavioral protocol that purports to show recovery from amnesia as a method of understanding the nature of amnesia.

Failure, Neuroscience and Success: Differentiating the pedagogies of music technology from electroacoustic composition

2013 ◽  
Vol 18 (2) ◽  
pp. 190-200
Author(s):  
Christopher J. Keyes
Keyword(s):  
Learning Environments ◽  
Memory Systems ◽  
Significant Degree ◽  
Music Technology ◽  
Long Term Memory ◽  
Successful Model ◽  
In The Beginning ◽  
The Brain ◽  
Pedagogical Approaches

Although the pedagogy of music technology more closely resembles that of other academic subjects, the teaching of electroacoustic composition involves a significant degree of creativity, and thus relies on different creativity-specific parts of the brain and memory systems (Lehmann 2007). This paper reviews recent neuroscientific research that may assist differentiation between effective pedagogical approaches of these two subjects where knowledge is stored in separate, discrete and sometimes competing long-term memory locations (Cotterill 2001). It argues that, because of these differences, the learning of music technology and electroacoustic composition is best kept separate, at least in the beginning stages. These points are underscored by an example of a demonstrably failed pedagogical model for teaching electroacoustic composition contrasted with a subsequent highly successful model employed in the same university music programme; an experience that may translate well to other learning environments.

Neuromagnetic reflections of harmony and constraint violations in Turkish

2011 ◽  
Vol 2 (1) ◽  
Author(s):  
Mathias Scharinger ◽  
William J. Idsardi ◽  
Samantha Poe
Keyword(s):  
Optimality Theory ◽  
Mismatch Negativity ◽  
Probabilistic Approach ◽  
Vowel Harmony ◽  
Long Term Memory ◽  
Memory Representation ◽  
Term Memory ◽  
Detection Response ◽  
The Brain

AbstractVowel harmony is a phonotactic principle that requires adjacent vowels to agree in certain vowel features. Phonological theory considers this principle to be represented in one's native grammar, but its abstractness and perceptual consequences remain a matter of debate. In this paper, we are interested in the brain's response to violations of harmony in Turkish. For this purpose, we test two acoustically close and two acoustically distant vowel pairs in Turkish, involving different kinds of harmony violations. Our measure is the Mismatch Negativity (MMN), an automatic change detection response of the brain that has previously been applied for the study of native phoneme representations in a variety of languages. The results of our experiment support the view that vowel harmony is a phonological principle with a language-specific long-term memory representation. Asymmetries in MMN responses support a phonological analysis of the pattern of results, but do not provide evidence for a pure acoustic or a pure probabilistic approach. Phonological analyses are given within Optimality Theory (OT) and within an underspecification account.

A Memória de Longo Prazo e a Análise Sobre sua Função no Processo de Aprendizagem

2018 ◽  
Vol 19 (1) ◽  
pp. 66
Author(s):  
Lia Almeida Mapurunga ◽  
Elcyana Bezerra Elcyana Bezerra Carvalho
Keyword(s):  
Cognitive Psychology ◽  
Learning Strategies ◽  
Long Term Memory ◽  
Term Memory ◽  
Positive Effects ◽  
Bibliographical Survey ◽  
And Function ◽  
The Relationship ◽  
The Brain

A neurociência é uma ciência natural que estuda a função e a estrutura, que compõem o cérebro. A educação, embora tenha outra natureza, tem tido muitos benefícios com as contribuições que a neurociência tem para oferecer. Como o cérebro aprende e por que aprende traz para o ensino o objetivo e a função de criar condições (entre estratégias, recursos e adequação do meio), para que ocorra a aprendizagem. E, para que essa ocorra, é necessário que as funções mentais superiores, como a memória, estejam envolvidas. O objetivo deste estudo consiste em fazer uma revisão de literatura para conhecer a função da memória de longo prazo na aprendizagem, analisar os mecanismos neurobiológicos, que ocorrem durante esse processo e algumas estratégias de aprendizagem, que se utilizam da memória como recurso. Para isso, foi realizado no período de agosto a outubro de 2016, um levantamento bibliográfico nas bases de dados Scielo, Capes, Bireme e Google Acadêmico, buscando artigos científicos, que poderiam trazer alguma contribuição na construção dessa pesquisa. Foram selecionados, preferencialmente, os que continham enfoque na relação entre aprendizagem e memória, tanto na perspectiva da neurociência, quanto da psicologia cognitiva, trazendo argumentos que pudessem  comprovar o entendimento das estratégias de aprendizagem, a partir da memória de longo prazo. Também foram selecionados livros que apresentavam apoio às temáticas discorridas para esse trabalho, possibilitando essa relação. Os resultados apontam que estratégias de aprendizagens, que utilizam a memória, produzem efeitos positivos para a retenção de longo prazo.Palavras-chave: Aprendizagem. Neurociências. Estratégias de Aprendizagem.AbstractNeuroscience is a natural science that studies the function and structure that forms the brain. Although education has another nature, it has had many benefits from the contributions that neuroscience has to offer. How the brain learns and why it learns brings to teaching the intent and function to create conditions (among strategies, resources and suitability to the environment) so that learning can happen. And, for it to occur, it is  necessary that higher mental functions, such as memory, beinvolved. The purpose of this study is to do a literature review to get to know the function of long-term memory on the learning process, to analyze the neurobiological mechanisms that happen during that process, and some learning strategies that use memory as a resource. Therefore a bibliographical survey was conducted at the databases Scielo, Capes, Bireme and Academic Google, from August to October 2016, searching for scientific articles that could contribute somehow on the construction of this research. The articles that used the neuroscience perspective or the cognitive psychology to focus on the relationship  between learning and memory were chosen, preferentially those whose arguments could prove the  learning strategies understanding about he long-term memory. Books supporting the themes discussed for this work were also selected, creating, therefore, a relationship. The results show that learning strategies that use memory have positive effects for long-term retention.Keywords: Learning. Neuroscience. Learning Strategies.

A Mathematical Model of Short-Term Memory

SIMULATION ◽  
1964 ◽  
Vol 3 (6) ◽  
pp. 46-51
Author(s):  
W. Ross Adey ◽  
N.V. Findler
Keyword(s):  
Electromagnetic Waves ◽  
Short Term Memory ◽  
Threshold Value ◽  
Long Term Memory ◽  
Short Term ◽  
Term Memory ◽  
Neuron Density ◽  
Receptor Neurons ◽  
The Brain

It is attempted in this paper to give a mathematical description of the short-term memory. Instead of using the microscopic properties of individual neu rons, such as the number of interconnections, neuron density, threshold value, etc., the cerebral cortex is regarded as a "neuron gas" that is a vast conglomer ate of neurons with statistically distributed charac teristics. Stimuli from the environment cause the receptor neurons to emit virtual electromagnetic waves into the brain. A self-optimizing process of the brain tis sue is here described by which the useful, informa tion-carrying energy reaching the long-term memory tends to maximum. It is emphasized that in the following a brain model is described and the physical processes in volved may have no direct equivalent in reality.

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