scholarly journals Working memory as persistent neural activity

2019 ◽  
Author(s):  
Joshua J. Foster ◽  
Edward K. Vogel ◽  
Ed Awh
Keyword(s):  
Working Memory ◽  
Cognitive Processing ◽  
Neural Activity ◽  
Operational Definition ◽  
Task Demands ◽  
Neural Representation ◽  
Long Term Memory ◽  
Intelligent Behavior ◽  
Dynamic Collaboration ◽  
Definition Of

Working memory (WM) is an online memory system that allows us to hold information “in mind” in service of ongoing cognitive processing. Here, we emphasize that short-term retention of information typically involves an interplay between WM and long-term memory (LTM), especially when task demands or interruptions divert our focus from remembered items. We suggest that active neural representation may distinguish between “online” representations in WM and “offline” representations in LTM. This perspective is at odds with “activity-silent” models of WM, which hold that WM representations can be sustained without persistent neural activity. We suggest that activity-silent representations might be more productively conceptualized as offline representations in LTM because accessing these representations shows multiple signatures of retrieval from LTM. Moreover, active neural traces track WM load, predict individual differences in performance, and respect sharp item limits in WM storage. Thus, we argue that using neural activity as an operational definition of WM may provide strong traction for studying the dynamic collaboration between WM and LTM that is critical for intelligent behavior.

Manifold Visual Working Memory

2020 ◽  
pp. 311-332
Author(s):  
Nicole Hakim ◽  
Edward Awh ◽  
Edward K. Vogel
Keyword(s):  
Working Memory ◽  
Visual Working Memory ◽  
Neural Activity ◽  
Long Term Memory ◽  
Term Memory ◽  
Memory Representations ◽  
Latent Representations ◽  
Definition Of ◽  
Spatial Locations

Visual working memory allows us to maintain information in mind for use in ongoing cognition. Research on visual working memory often characterizes it within the context of its interaction with long-term memory (LTM). These embedded-processes models describe memory representations as existing in three potential states: inactivated LTM, including all representations stored in LTM; activated LTM, latent representations that can quickly be brought into an active state due to contextual priming or recency; and the focus of attention, an active but sharply limited state in which only a small number of items can be represented simultaneously. This chapter extends the embedded-processes framework of working memory. It proposes that working memory should be defined operationally based on neural activity. By defining working memory in this way, the important theoretical distinction between working memory and LTM is maintained, while still acknowledging that they operate together. It is additionally proposed that active working memory should be further subdivided into at least two subcomponent processes that index item-based storage and currently prioritized spatial locations. This fractionation of working memory is based on recent research that has found that the maintenance of information distinctly relies on item-based representations as well as prioritization of spatial locations. It is hoped that this updated framework of the definition of working memory within the embedded-processes model provides further traction for understanding how we maintain information in mind.

scholarly journals Mirror neurons are modulated by grip force and reward expectation in the sensorimotor cortices (S1, M1, PMd, PMv)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Md Moin Uddin Atique ◽  
Joseph Thachil Francis
Keyword(s):  
Neural Activity ◽  
Visual Information ◽  
Mirror Neurons ◽  
Grip Force ◽  
Neural Representation ◽  
Virtual Object ◽  
Time Lags ◽  
Subjective Value ◽  
Machine Interface ◽  
Definition Of

AbstractMirror Neurons (MNs) respond similarly when primates make or observe grasping movements. Recent work indicates that reward expectation influences rostral M1 (rM1) during manual, observational, and Brain Machine Interface (BMI) reaching movements. Previous work showed MNs are modulated by subjective value. Here we expand on the above work utilizing two non-human primates (NHPs), one male Macaca Radiata (NHP S) and one female Macaca Mulatta (NHP P), that were trained to perform a cued reward level isometric grip-force task, where the NHPs had to apply visually cued grip-force to move and transport a virtual object. We found a population of (S1 area 1–2, rM1, PMd, PMv) units that significantly represented grip-force during manual and observational trials. We found the neural representation of visually cued force was similar during observational trials and manual trials for the same units; however, the representation was weaker during observational trials. Comparing changes in neural time lags between manual and observational tasks indicated that a subpopulation fit the standard MN definition of observational neural activity lagging the visual information. Neural activity in (S1 areas 1–2, rM1, PMd, PMv) significantly represented force and reward expectation. In summary, we present results indicating that sensorimotor cortices have MNs for visually cued force and value.

scholarly journals Expectations of Task Demands Dissociate Working Memory and Long-Term Memory Systems

2015 ◽  
Vol 26 (3) ◽  
pp. 1176-1186 ◽  
Author(s):  
T. P. Zanto ◽  
W. C. Clapp ◽  
M. T. Rubens ◽  
J. Karlsson ◽  
A. Gazzaley
Keyword(s):  
Working Memory ◽  
Memory Systems ◽  
Task Demands ◽  
Long Term Memory ◽  
Term Memory

scholarly journals Attributes of Effective Lecturing in the College Classroom

1993 ◽  
Vol 23 (2) ◽  
pp. 1-18
Author(s):  
Dieter J. Schonwetter
Keyword(s):  
Student Learning ◽  
Cognitive Processing ◽  
Empirical Studies ◽  
Operational Definition ◽  
Research Literature ◽  
College Classroom ◽  
Major Research ◽  
Critical Issues ◽  
Research Findings ◽  
Definition Of

The following paper highlights research on effective lecturing in the college classroom. First, critical issues concerning the operational definition of effective lecturing and the measurement criteria used to denote it are addressed. Next, major research findings are reported, beginning with correlational information reported by descriptive studies and ending with causal findings demonstrated by empirical studies. Current research literature identifies the following lecture attributes as important for student learning: expressiveness, clarity, and organization. These dimensions are defined by low-inference behaviours and supported by empirical studies. Furthermore, links between lecture attributes and certain student cognitive processing activities, explaining the facilitative qualities of effective lecturing on student learning, are hypothesized. Finally, implications for both practitioners and researchers are discussed.

Evidence for Linear but Not Helical Automatic Representation of Pitch in the Human Auditory System

2019 ◽  
Vol 31 (5) ◽  
pp. 669-685 ◽  
Author(s):  
Tamar I. Regev ◽  
Israel Nelken ◽  
Leon Y. Deouell
Keyword(s):  
Working Memory ◽  
Cognitive Processes ◽  
Neural Activity ◽  
Pure Tone ◽  
Automatic Detection ◽  
Complex Tone ◽  
Neural Representation ◽  
Pitch Height ◽  
G 21 ◽  
Complex Tones

The perceptual organization of pitch is frequently described as helical, with a monotonic dimension of pitch height and a circular dimension of pitch chroma, accounting for the repeating structure of the octave. Although the neural representation of pitch height is widely studied, the way in which pitch chroma representation is manifested in neural activity is currently debated. We tested the automaticity of pitch chroma processing using the MMN—an ERP component indexing automatic detection of deviations from auditory regularity. Musicians trained to classify pure or complex tones across four octaves, based on chroma—C versus G (21 participants, Experiment 1) or C versus F# (27, Experiment 2). Next, they were passively exposed to MMN protocols designed to test automatic detection of height and chroma deviations. Finally, in an “attend chroma” block, participants had to detect the chroma deviants in a sequence similar to the passive MMN sequence. The chroma deviant tones were accurately detected in the training and the attend chroma parts both for pure and complex tones, with a slightly better performance for complex tones. However, in the passive blocks, a significant MMN was found only to height deviations and complex tone chroma deviations, but not to pure tone chroma deviations, even for perfect performers in the active tasks. These results indicate that, although height is represented preattentively, chroma is not. Processing the musical dimension of chroma may require higher cognitive processes, such as attention and working memory.

scholarly journals Mindfulness meditation alters neural activity underpinning working memory during tactile distraction

2019 ◽  
Author(s):  
Michael Yufeng Wang ◽  
Gabrielle Freedman ◽  
Kavya Raj ◽  
Bernadette Mary Fitzgibbon ◽  
Caley Sullivan ◽  
...  
Keyword(s):  
Working Memory ◽  
Neural Activity ◽  
Tactile Stimulation ◽  
Mindfulness Meditation ◽  
Brain Activity ◽  
Alpha Activity ◽  
Task Demands ◽  
Attentional Processes ◽  
Attentional Function ◽  
Tactile Stimuli

AbstractEvidence suggests that mindfulness meditation (MM) improves selective attention and reduces distractibility by enhancing top-down neural modulation. Altered P300 and alpha neural activity from MM have been identified and may reflect the neural changes that underpin these improvements. Given the proposed role of alpha activity in supressing processing of task-irrelevant information, it is theorised that altered alpha activity may underlie increased availability of neural resources in meditators. The present study investigated attentional function in meditators using a cross-modal study design, examining the P300 during working memory (WM) and alpha activity during concurrent distracting tactile stimuli. Thirty-three meditators and 27 healthy controls participated in the study. Meditators showed a more frontal distribution of P300 neural activity following WM stimuli (p = 0.005, η² = 0.060) and more modulation of alpha activity at parietal-occipital regions between single (tactile stimulation only) and dual task demands (tactile stimulation plus WM task) (p < 0.001, η² = 0.065). Additionally, meditators performed more accurately than controls (p = 0.038, η² = 0.067). The altered distribution of neural activity concurrent with improved WM performance suggests greater attentional resources dedicated to task related functions such as WM in meditators. Thus, meditation-related neural changes are likely multi-faceted involving both altered distribution and also amplitudes of brain activity, enhancing attentional processes depending on task requirements.

scholarly journals Network Mechanisms Underlying the Role of Oscillations in Cognitive Tasks

2018 ◽  
Author(s):  
Helmut Schmidt ◽  
Daniele Avitabile ◽  
Ernest Montbrió ◽  
Alex Roxin
Keyword(s):  
Working Memory ◽  
Cognitive Processing ◽  
Network Dynamics ◽  
Task Demands ◽  
Cognitive Tasks ◽  
Oscillatory Activity ◽  
Memory Recall ◽  
Mean Field Equations ◽  
Memory States ◽  
Network States

AbstractOscillatory activity robustly correlates with task demands during many cognitive tasks. However, not only are the network mechanisms underlying the generation of these rhythms poorly understood, but it is also still unknown to what extent they may play a functional role, as opposed to being a mere epiphenomenon. Here we study the mechanisms underlying the influence of oscillatory drive on network dynamics related to cognitive processing in simple working memory (WM), and memory recall tasks. Specifically, we investigate how the frequency of oscillatory input interacts with the intrinsic dynamics in networks of recurrently coupled spiking neurons to cause changes of state: the neuronal correlates of the corresponding cognitive process. We find that slow oscillations, in the delta and theta band, are effective in activating network states associated with memory recall by virtue of the hysteresis in sweeping through a saddle-node bifurcation. On the other hand, faster oscillations, in the beta range, can serve to clear memory states by resonantly driving transient bouts of spike synchrony which destabilize the activity. We leverage a recently derived set of exact mean-field equations for networks of quadratic integrate-and-fire neurons to systematically study the bifurcation structure in the periodically forced spiking network. Interestingly, we find that the oscillatory signals which are most effective in allowing flexible switching between network states are not smooth, pure sinusoids, but rather burst-like, with a sharp onset. We show that such periodic bursts themselves readily arise spontaneously in networks of excitatory and inhibitory neurons, and that the burst frequency can be tuned via changes in tonic drive. Finally, we show that oscillations in the gamma range can actually stabilize WM states which otherwise would not persist.Author SummaryOscillations are ubiquitous in the brain and often correlate with distinct cognitive tasks. Nonetheless their role in shaping network dynamics, and hence in driving behavior during such tasks is poorly understood. Here we provide a comprehensive study of the effect of periodic drive on neuronal networks exhibiting multistability, which has been invoked as a possible circuit mechanism underlying the storage of memory states. We find that oscillatory drive in low frequency bands leads to robust switching between stored patterns in a Hopfield-like model, while oscillations in the beta band suppress sustained activity altogether. Furthermore, inputs in the gamma band can lead to the creation of working-memory states, which otherwise do not exist in the absence of oscillatory drive.

scholarly journals Mirror Neurons are Modulated by Reward Expectation and Grip Force in the Sensorimotor Cortices (S1, M1, PMd, PMv)

2021 ◽  
Author(s):  
Md Moin Uddin Atique ◽  
Joseph Thachil Francis
Keyword(s):  
Neural Activity ◽  
Visual Information ◽  
Mirror Neurons ◽  
Grip Force ◽  
Neural Representation ◽  
Virtual Object ◽  
Time Lags ◽  
Subjective Value ◽  
Machine Interface ◽  
Definition Of

AbstractMirror Neurons (MN) respond similarly when primates make, or observe, grasping movements. Recent work indicates that reward expectation influences M1 during manual, observational, and Brain Machine Interface (BMI) reaching movements. Previous work showed MN are modulated by subjective value. Here we expand on the above work utilizing two non-human primates (NHPs), one male Macaca Radiata (NHP S) and one female Macaca Mulatta (NHP P), that were trained to perform a cued reward level isometric grip force task, where the NHPs had to apply visually cued grip force to move and transport a virtual object. We found a population of (S1, M1, PMd, PMv) units that significantly represented grip force during manual and observational trials. We found the neural representation of visually cued force was similar during observational trials and manual trials for the same units, however, the representation was weaker during observational trials. Comparing changes in neural time lags between manual and observational tasks indicated that a subpopulation fit the standard MN definition of observational neural activity lagging the visual information. Neural activity in (S1, M1, PMd, PMv) significantly represented force and reward expectation. In summary, we present results indicating that sensorimotor cortices have MN for visually cued force and value.

scholarly journals Flexible information coding in frontoparietal cortex across the functional stages of cognitive processing

2018 ◽  
Author(s):  
Joyce M. G. Vromen ◽  
Stefanie I. Becker ◽  
Oliver Baumann ◽  
Jason B. Mattingley ◽  
Roger W. Remington
Keyword(s):  
Cognitive Processing ◽  
Neural Activity ◽  
Target Selection ◽  
Task Demands ◽  
Anterior Cingulate ◽  
Information Representation ◽  
Complex Tasks ◽  
Cognitive Domains ◽  
Frontoparietal Cortex ◽  
Response Execution

AbstractNeural activity in frontoparietal cortex shows overlap across cognitive domains and has been proposed to reflect flexible information processing according to current task demands (Dosenbach et al., 2007; Duncan, 2001). However, a strong assertion of flexibility requires investigating activity across stages of cognitive processing. The current study assessed neural activity in Multiple Demand (MD) regions across the stages of processing that form the core of long-standing cognitive models (Welford, 1952). Specifically, many complex tasks share a comparable structure of subsequent operations: target selection, stimulus-response (SR) mapping, and response execution. We independently manipulated the difficulty of target selection and SR mapping in identical stimulus displays and assessed changes in frontoparietal activity with increased demands in either stage. The results confirmed flexibility in MD regions, with enhanced information representation during difficult target selection as well as SR mapping. Additionally, anterior insula (AI) and anterior cingulate cortex (ACC) showed preferential representation of SR stage information, whereas the medial frontal gyrus (MFG) and inferior parietal sulcus (IPS) showed preferential representation of target selection-stage information. Together these results suggest that MD regions dynamically alter the information they represent with changing task demands. This is the first study to demonstrate that MD regions support flexible goal-directed cognition across multiple processing stages. At the same time we show a preference for the representation of information from a specific processing stage in a subset of MD regions.Significance StatementGoal-directed cognition in complex tasks is critical to key life outcomes including longevity and academic performance. Nevertheless, the mechanisms underlying cognition in complex tasks are not well understood. Distinct neural networks are critical to the navigation of specific cognitive domains (e.g. attention), but frontoparietal activity shows cross-domain and -task overlap and supports flexible representation of goal-critical information. This study links flexible frontoparietal processing to longstanding models of meta-cognition that propose a unifying structure of operations underlying most tasks: target selection, SR mapping, and response execution. Our results demonstrate that flexible information representation in frontoparietal cortex is not limited to the SR mapping stage, but applies across the functional stages of cognitive processing, thus maximizing neural efficiency and supporting flexible cognition.

Conceptual short-term memory (CSTM) supports core claims of Christiansen and Chater

2016 ◽  
Vol 39 ◽  
Author(s):  
Mary C. Potter
Keyword(s):  
Working Memory ◽  
Rapid Serial Visual Presentation ◽  
Language Comprehension ◽  
Short Term Memory ◽  
Visual Presentation ◽  
Long Term Memory ◽  
Short Term ◽  
Term Memory ◽  
Use Of Knowledge

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.

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