scholarly journals Dependence of Working Memory on Coordinated Activity Across Brain Areas

2022 ◽  
Vol 15 ◽  
Author(s):  
Ehsan Rezayat ◽  
Kelsey Clark ◽  
Mohammad-Reza A. Dehaqani ◽  
Behrad Noudoost
Keyword(s):  
Working Memory ◽  
Brain Area ◽  
Critical Role ◽  
Brain Disorders ◽  
Brain Areas ◽  
Neural Substrate ◽  
Oscillatory Power ◽  
Experimental Findings ◽  
Neural Signatures

Neural signatures of working memory (WM) have been reported in numerous brain areas, suggesting a distributed neural substrate for memory maintenance. In the current manuscript we provide an updated review of the literature focusing on intracranial neurophysiological recordings during WM in primates. Such signatures of WM include changes in firing rate or local oscillatory power within an area, along with measures of coordinated activity between areas based on synchronization between oscillations. In comparing the ability of various neural signatures in any brain area to predict behavioral performance, we observe that synchrony between areas is more frequently and robustly correlated with WM performance than any of the within-area neural signatures. We further review the evidence for alteration of inter-areal synchrony in brain disorders, consistent with an important role for such synchrony during behavior. Additionally, results of causal studies indicate that manipulating synchrony across areas is especially effective at influencing WM task performance. Each of these lines of research supports the critical role of inter-areal synchrony in WM. Finally, we propose a framework for interactions between prefrontal and sensory areas during WM, incorporating a range of experimental findings and offering an explanation for the observed link between intra-areal measures and WM performance.

scholarly journals Prefrontal and Parietal Attractor Networks Mediate Working Memory Judgments

2020 ◽  
Author(s):  
Sihai Li ◽  
Christos Constantinidis ◽  
Xue-Lian Qi
Keyword(s):  
Working Memory ◽  
Prefrontal Cortex ◽  
Dorsolateral Prefrontal Cortex ◽  
Critical Role ◽  
Memory Task ◽  
Delayed Response ◽  
Persistent Activity ◽  
Neural Basis ◽  
Brain Areas ◽  
Dorsolateral Prefrontal

ABSTRACTThe dorsolateral prefrontal cortex plays a critical role in spatial working memory and its activity predicts behavioral responses in delayed response tasks. Here we addressed whether this predictive ability extends to categorical judgments based on information retained in working memory, and is present in other brain areas. We trained monkeys in a novel, Match-Stay, Nonmatch-Go task, which required them to observe two stimuli presented in sequence with an intervening delay period between them. If the two stimuli were different, the monkeys had to saccade to the location of the second stimulus; if they were the same, they held fixation. Neurophysiological recordings were performed in areas 8a and 46 of the dlPFC and 7a and lateral intraparietal cortex (LIP) of the PPC. We hypothesized that random drifts causing the peak activity of the network to move away from the first stimulus location and towards the location of the second stimulus would result in categorical errors. Indeed, for both areas, when the first stimulus appeared in a neuron’s preferred location, the neuron showed significantly higher firing rates in correct than in error trials. When the first stimulus appeared at a nonpreferred location and the second stimulus at a preferred, activity in error trials was higher than in correct. The results indicate that the activity of both dlPFC and PPC neurons is predictive of categorical judgments of information maintained in working memory, and the magnitude of neuronal firing rate deviations is revealing of the contents of working memory as it determines performance.SIGNIFICANCE STATEMENTThe neural basis of working memory and the areas mediating this function is a topic of controversy. Persistent activity in the prefrontal cortex has traditionally been thought to be the neural correlate of working memory, however recent studies have proposed alternative mechanisms and brain areas. Here we show that persistent activity in both the dorsolateral prefrontal cortex and posterior parietal cortex predicts behavior in a working memory task that requires a categorical judgement. Our results offer support to the idea that a network of neurons in both areas act as an attractor network that maintains information in working memory, which informs behavior.

scholarly journals May the force be with you: Transfer of healthy mitochondria from stem cells to stroke cells

2018 ◽  
Vol 39 (2) ◽  
pp. 367-370 ◽  
Author(s):  
Cesar V Borlongan ◽  
Hung Nguyen ◽  
Trenton Lippert ◽  
Eleonora Russo ◽  
Julian Tuazon ◽  
...  
Keyword(s):  
United States ◽  
Stem Cells ◽  
Therapeutic Option ◽  
Critical Role ◽  
The United States ◽  
Brain Disorders ◽  
Mitochondrial Dysfunctions ◽  
Limited Therapeutic Option ◽  
The World

Stroke is a major cause of death and disability in the United States and around the world with limited therapeutic option. Here, we discuss the critical role of mitochondria in stem cell-mediated rescue of stroke brain by highlighting the concept that deleting the mitochondria from stem cells abolishes the cells’ regenerative potency. The application of innovative approaches entailing generation of mitochondria-voided stem cells as well as pharmacological inhibition of mitochondrial function may elucidate the mechanism underlying transfer of healthy mitochondria to ischemic cells, thereby providing key insights in the pathology and treatment of stroke and other brain disorders plagued with mitochondrial dysfunctions.

scholarly journals Neural Mechanisms in Eating Behaviors: A Pilot fMRI Study of Emotional Processing

2020 ◽  
Vol 17 (3) ◽  
pp. 225-236 ◽  
Author(s):  
Rosa M. Molina-Ruiz ◽  
T. García-Saiz ◽  
Jeffrey C.L. Looi ◽  
E. Via Virgili ◽  
M. Rincón Zamorano ◽  
...  
Keyword(s):  
Emotional Processing ◽  
Eating Behaviors ◽  
Brain Area ◽  
Self Control ◽  
Women Patients ◽  
Brain Areas ◽  
Fmri Study ◽  
Neural Substrate ◽  
Dorsolateral Prefrontal ◽  
Functional Relevance

Objective Emotional processing dysfunction evident in eating disorders (ED) such as anorexia nervosa (AN) and bulimia nervosa (BN), is considered relevant to the development and maintenance of these disorders. The purpose of the current functional magnetic resonance imaging (fMRI) study was to pilot a comparison of the activity of the fronto-limbic and fronto-striatal brain areas during an emotion processing task in persons with ED.Methods 24 women patients with ED were scanned, while showing emotionally stimulating (pleasant, unpleasant) and neutral images from the International Affective Picture System (IAPS).Results During the pleasant condition, significant differences in Dorsolateral Prefrontal Cortex (DLPFC) activations were found with AN participants presenting greater activation compared to BN and ED comorbid groups (EDc) and healthy controls also showing greater activation of this brain area compared to BN and EDc. Left putamen was less activated in EDc compared to both controls (C) and AN. During the unpleasant condition, AN participants showed hyperactivation of the Orbito-frontal Cortex (OFC) when compared to EDc.Conclusion This study highlights the potential functional relevance of brain areas that have been associated with self-control. These findings should help advance understanding the neural substrate of ED, though they should be considered as preliminary and be cautiously interpreted.

scholarly journals Regulation of cellular plasticity and resilience by mood stabilizers: the role of AMPA receptor trafficking

2004 ◽  
Vol 6 (2) ◽  
pp. 143-155
Keyword(s):  
Mood Disorders ◽  
Neural Plasticity ◽  
Neuronal Plasticity ◽  
Brain Volume ◽  
Critical Role ◽  
Receptor Trafficking ◽  
Mood Stabilizers ◽  
Brain Areas ◽  
Cellular Resilience

There is increasing evidence from a variety of sources that severe mood disorders are associated with regional reductions in brain volume, as well as reductions in the number, size, and density of glia and neurons in discrete brain areas. Although the precise pathophysiology underlying these morphometric changes remains to be fully elucidated, the data suggest that severe mood disorders are associated with impairments of structural plasticity and cellular resilience. In this context, it is noteworthy that a growing body of data suggests that the glutamaiergic system (which is known to play a major role in neuronal plasticity and cellular resilience) may be involved in the pathophysiology and treatment of mood disorders. Glutamate α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) GluR1 receptor trafficking plays a critical role in regulating various forms of neural plasticity. It is thus noteworthy that recent studies have shown that structurally dissimilar mood stabilizers lithium and valproate regulate GluR1 receptor subunit trafficking and localization at synapses. These studies suggest that regulation of glutamatergically mediated synaptic plasticity may play a role in the treatment of mood disorders, and raises the possibility that agents more directly affecting synaptic GluR1 represent novel therapies for these devastating illnesses.

scholarly journals Genetic recovery of ErbB4 in adulthood partially restores brain functions in null mice

2018 ◽  
Vol 115 (51) ◽  
pp. 13105-13110 ◽  
Author(s):  
Hongsheng Wang ◽  
Fang Liu ◽  
Wenbing Chen ◽  
Xiangdong Sun ◽  
Wanpeng Cui ◽  
...  
Keyword(s):  
Neural Development ◽  
Critical Role ◽  
Gaba Release ◽  
Brain Disorders ◽  
Gabaergic Transmission ◽  
Brain Functions ◽  
Adult Mice ◽  
Mutant Strains ◽  
And Behavior

Neurotrophic factor NRG1 and its receptor ErbB4 play a role in GABAergic circuit assembly during development. ErbB4 null mice possess fewer interneurons, have decreased GABA release, and show impaired behavior in various paradigms. In addition, NRG1 and ErbB4 have also been implicated in regulating GABAergic transmission and plasticity in matured brains. However, current ErbB4 mutant strains are unable to determine whether phenotypes in adult mutant mice result from abnormal neural development. This important question, a glaring gap in understanding NRG1–ErbB4 function, was addressed by using two strains of mice with temporal control of ErbB4 deletion and expression, respectively. We found that ErbB4 deletion in adult mice impaired behavior and GABA release but had no effect on neuron numbers and morphology. On the other hand, some deficits due to the ErbB4 null mutation during development were alleviated by restoring ErbB4 expression at the adult stage. Together, our results indicate a critical role of NRG1–ErbB4 signaling in GABAergic transmission and behavior in adulthood and suggest that restoring NRG1–ErbB4 signaling at the postdevelopmental stage might benefit relevant brain disorders.

scholarly journals Effect of focus on verbal working memory: Critical role of the focus word in reading

2002 ◽  
Vol 30 (4) ◽  
pp. 562-571 ◽  
Author(s):  
Mariko Osaka ◽  
Yukiko Nishizaki ◽  
Mie Komori ◽  
Naoyuki Osaka
Keyword(s):  
Working Memory ◽  
Critical Role ◽  
Verbal Working Memory

scholarly journals FVS 2.0: A Unifying Framework for Understanding the Factors of Visual-Attentional Processing

2021 ◽  
Author(s):  
Liqiang Huang
Keyword(s):  
Brain Area ◽  
General Purpose ◽  
Traditional View ◽  
Visual Features ◽  
Individual Item ◽  
Brain Areas ◽  
Attentional Processing ◽  
Conscious Level ◽  
The Relationship

Across a broad range of stimulus types and tasks (16 stimulus types × 26 tasks, 1744 observers in total), the present study employed an individual-item differences analysis to extract the factors of visual-attentional processing. Three orthogonal factors were identified and they can be summarized as an FVS 2.0 framework: featural, visual, and spatial strengths. Apart from one exception (low-level motion), the FVS 2.0 framework accounts for the vast majority (95.4%) of the variances in the 25 tasks. Therefore, the three straightforward factors provide a unifying framework for understanding the relationship between stimulus types as well as those between tasks. Combining these and other related results, the role of preattentive features seems to be rather different from the traditional view: visual features are general-purpose, exclusive, innate, constancy-based, and keyword-like. A GEICK conjecture is proposed which suggests that the features are conscious-level keywords generated by the specific brain area of V4 and/or IT and then used by all other brain areas.

scholarly journals Parsing-error-Hindi

2021 ◽  
Author(s):  
Samar Husain
Keyword(s):  
Working Memory ◽  
Sentence Comprehension ◽  
Native Speakers ◽  
Critical Role ◽  
The Face ◽  
Case Markers ◽  
Effective Use ◽  
Verbal Relations ◽  
Memory Constraints

The role of prediction during sentence comprehension is widely acknowledged to be very critical in SOV languages. Robust clause-fi?nal verbal prediction and its maintenance have been invoked to explain eff?ects such as anti-locality and lack of structural forgetting. At the same time, there is evidence that these languages avoid increased preverbal phrase complexity due to working-memory constraints. Given the critical role of prediction in processing of SOV languages, in this work, we study verbal predictions in Hindi (an SOV language) to investigate its robustness and fallibility using a series of completion studies. Analyses of verbal completions based on grammaticality (grammatical vs ungrammatical) as well as their syntactic property (in terms of verb class) show, as expected, frequent grammatical completions based on effective use of preverbal nouns and case-markers. However, there were also high instances of ungrammatical completions. In particular, consistent errors were made in conditions with 3 animate nouns with unique/similar case-markers. These errors increased in the face of adjuncts of di?ffering complexity following the preverbal nouns. The grammatical and ungrammatical completions show that native speakers of Hindi posit structures with at most 2 verbal heads and 5 core verbal relations, thus highlighting an upper bound to verbal prediction and its maintenance in such con?figurations. A rating study con?firmed that certain errors found in completion tasks can lead to grammatical illusions. Further, a detailed analysis of the completion errors in such cases revealed that the parser ignores the complete preverbal nominal features of the input and instead selectively reconstructs the input based on their frequency in the language to form illicit parses at the expense of globally consistent parses. Together, the results show that while preverbal cues are eff?ectively employed by the parser to make clause ?final structural predictions, the parsing system breaks down when the number of predicted verbs/relations exceeds beyond a certain threshold. In effect, the results suggests that processing in SOV languages is susceptible to center-embeddings similar to that in SVO languages. This highlights the over-arching influence of working-memory constraints during sentence comprehension and thereby on the parser to posit less complex structures.

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