scholarly journals Circuit mechanisms for the maintenance and manipulation of information in working memory

2018 ◽  
Author(s):  
Nicolas Y. Masse ◽  
Guangyu R. Yang ◽  
H. Francis Song ◽  
Xiao-Jing Wang ◽  
David J. Freedman

SummaryRecently it has been proposed that information in short-term memory may not always be stored in persistent neuronal activity, but can be maintained in “activity-silent” hidden states such as synaptic efficacies endowed with short-term plasticity (STP). However, working memory involves manipulation as well as maintenance of information in the absence of external stimuli. In this work, we investigated working memory representation using recurrent neural network (RNN) models trained to perform several working memory dependent tasks. We found that STP can support the short-term maintenance of information provided that the memory delay period is sufficiently short. However, in tasks that require actively manipulating information, persistent neuronal activity naturally emerges from learning, and the amount of persistent neuronal activity scales with the degree of manipulation required. These results shed insight into the current debate on working memory encoding, and suggest that persistent neural activity can vary markedly between tasks used in different experiments.

2016 ◽  
Vol 39 ◽  
Author(s):  
Mary C. Potter

AbstractRapid serial visual presentation (RSVP) of words or pictured scenes provides evidence for a large-capacity conceptual short-term memory (CSTM) that momentarily provides rich associated material from long-term memory, permitting rapid chunking (Potter 1993; 2009; 2012). In perception of scenes as well as language comprehension, we make use of knowledge that briefly exceeds the supposed limits of working memory.


2020 ◽  
Vol 63 (12) ◽  
pp. 4162-4178
Author(s):  
Emily Jackson ◽  
Suze Leitão ◽  
Mary Claessen ◽  
Mark Boyes

Purpose Previous research into the working, declarative, and procedural memory systems in children with developmental language disorder (DLD) has yielded inconsistent results. The purpose of this research was to profile these memory systems in children with DLD and their typically developing peers. Method One hundred four 5- to 8-year-old children participated in the study. Fifty had DLD, and 54 were typically developing. Aspects of the working memory system (verbal short-term memory, verbal working memory, and visual–spatial short-term memory) were assessed using a nonword repetition test and subtests from the Working Memory Test Battery for Children. Verbal and visual–spatial declarative memory were measured using the Children's Memory Scale, and an audiovisual serial reaction time task was used to evaluate procedural memory. Results The children with DLD demonstrated significant impairments in verbal short-term and working memory, visual–spatial short-term memory, verbal declarative memory, and procedural memory. However, verbal declarative memory and procedural memory were no longer impaired after controlling for working memory and nonverbal IQ. Declarative memory for visual–spatial information was unimpaired. Conclusions These findings indicate that children with DLD have deficits in the working memory system. While verbal declarative memory and procedural memory also appear to be impaired, these deficits could largely be accounted for by working memory skills. The results have implications for our understanding of the cognitive processes underlying language impairment in the DLD population; however, further investigation of the relationships between the memory systems is required using tasks that measure learning over long-term intervals. Supplemental Material https://doi.org/10.23641/asha.13250180


1997 ◽  
Author(s):  
Randall W. Engle ◽  
Stephen Tuholski ◽  
James Laughlin ◽  
Andrew Conway

Author(s):  
Steven J Hardy ◽  
Sarah E Bills ◽  
Emily R Meier ◽  
Jeffrey C Schatz ◽  
Katie J Keridan ◽  
...  

Abstract Objective Youth with sickle cell disease (SCD) are at risk for neurocognitive deficits including problems with working memory (WM), but few interventions to improve functioning exist. This study sought to determine the feasibility and efficacy of home-based, digital WM training on short-term memory and WM, behavioral outcomes, and academic fluency using a parallel group randomized controlled trial design. Methods 47 children (7–16 years) with SCD and short-term memory or WM difficulties were randomized to Cogmed Working Memory Training at home on a tablet device (N = 24) or to a standard care Waitlist group (N = 23) that used Cogmed after the waiting period. Primary outcomes assessed in clinic included performance on verbal and nonverbal short-term memory and WM tasks. Secondary outcomes included parent-rated executive functioning and tests of math and reading fluency. Results In the evaluable sample, the Cogmed group (N = 21) showed greater improvement in visual WM compared with the Waitlist group (N = 22; p = .03, d = 0.70 [CI95 = 0.08, 1.31]). When examining a combined sample of participants, those who completed ≥10 training sessions exhibited significant improvements in verbal short-term memory, visual WM, and math fluency. Adherence to Cogmed was lower than expected (M = 9.07 sessions, SD = 7.77), with 19 participants (41%) completing at least 10 sessions. Conclusions: Visual WM, an ability commonly affected by SCD, is modifiable with cognitive training. Benefits extended to verbal short-term memory and math fluency when patients completed a sufficient training dose. Additional research is needed to identify ideal candidates for training and determine whether training gains are sustainable and generalize to real-world outcomes.


Author(s):  
Francesco Panico ◽  
Stefania De Marco ◽  
Laura Sagliano ◽  
Francesca D’Olimpio ◽  
Dario Grossi ◽  
...  

AbstractThe Corsi Block-Tapping test (CBT) is a measure of spatial working memory (WM) in clinical practice, requiring an examinee to reproduce sequences of cubes tapped by an examiner. CBT implies complementary behaviors in the examiners and the examinees, as they have to attend a precise turn taking. Previous studies demonstrated that the Prefrontal Cortex (PFC) is activated during CBT, but scarce evidence is available on the neural correlates of CBT in the real setting. We assessed PFC activity in dyads of examiner–examinee participants while completing the real version of CBT, during conditions of increasing and exceeding workload. This procedure allowed to investigate whether brain activity in the dyads is coordinated. Results in the examinees showed that PFC activity was higher when the workload approached or reached participants’ spatial WM span, and lower during workload conditions that were largely below or above their span. Interestingly, findings in the examiners paralleled the ones in the examinees, as examiners’ brain activity increased and decreased in a similar way as the examinees’ one. In the examiners, higher left-hemisphere activity was observed suggesting the likely activation of non-spatial WM processes. Data support a bell-shaped relationship between cognitive load and brain activity, and provide original insights on the cognitive processes activated in the examiner during CBT.


2021 ◽  
Vol 13 (2) ◽  
pp. 164
Author(s):  
Chuyao Luo ◽  
Xutao Li ◽  
Yongliang Wen ◽  
Yunming Ye ◽  
Xiaofeng Zhang

The task of precipitation nowcasting is significant in the operational weather forecast. The radar echo map extrapolation plays a vital role in this task. Recently, deep learning techniques such as Convolutional Recurrent Neural Network (ConvRNN) models have been designed to solve the task. These models, albeit performing much better than conventional optical flow based approaches, suffer from a common problem of underestimating the high echo value parts. The drawback is fatal to precipitation nowcasting, as the parts often lead to heavy rains that may cause natural disasters. In this paper, we propose a novel interaction dual attention long short-term memory (IDA-LSTM) model to address the drawback. In the method, an interaction framework is developed for the ConvRNN unit to fully exploit the short-term context information by constructing a serial of coupled convolutions on the input and hidden states. Moreover, a dual attention mechanism on channels and positions is developed to recall the forgotten information in the long term. Comprehensive experiments have been conducted on CIKM AnalytiCup 2017 data sets, and the results show the effectiveness of the IDA-LSTM in addressing the underestimation drawback. The extrapolation performance of IDA-LSTM is superior to that of the state-of-the-art methods.


Author(s):  
Mirosław Pawlak ◽  
Adriana Biedroń

Abstract This paper reports the findings of a study that investigated the relationship between phonological short-term memory (PSTM), working memory capacity (WMC), and the level of mastery of L2 grammar. Grammatical mastery was operationalized as the ability to produce and comprehend English passive voice with reference to explicit and implicit (or highly automatized) knowledge. Correlational analysis showed that PSTM was related to implicit productive knowledge while WMC was linked to explicit productive knowledge. However, regression analysis showed that those relationships were weak and mediated by overall mastery of target language grammar, operationalized as final grades in a grammar course.


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