scholarly journals Adaptive learning is structure learning in time

2020 ◽  
Author(s):  
Linda Q. Yu ◽  
Robert C Wilson ◽  
Matthew R. Nassar
Keyword(s):  
Adaptive Learning ◽  
Structure Learning ◽  
Relevant Information ◽  
Neural Mechanisms ◽  
Multiple Sources ◽  
System View ◽  
Environmental Statistics ◽  
New Information ◽  
The Brain ◽  
Over Time

People use information flexibly. They often combine multiple sources of relevant information over time in order to inform decisions with little or no interference from intervening irrelevant sources. They adjust the degree to which they use new information over time rationally in accordance with environmental statistics and their own uncertainty. They can even use information gained in one situation to solve a problem in a very different one. Learning flexibly rests on the ability to infer the context at a given time, and therefore knowing which pieces of information to combine and which to separate. We review the psychological and neural mechanisms behind adaptive learning and structure learning to outline how people pool together relevant information, demarcate contexts, prevent interference between information collected in different contexts, and transfer information from one context to another. By examining all of these processes through the lens of optimal inference we bridge concepts from multiple fields to provide a unified multi-system view of how the brain exploits structure in time to optimize learning.

The Role of Revenue in Firm Valuation

2008 ◽  
Vol 22 (2) ◽  
pp. 199-222 ◽  
Author(s):  
Uday Chandra ◽  
Byung T. Ro
Keyword(s):  
Model Misspecification ◽  
Relevant Information ◽  
Firm Valuation ◽  
Summary Measure ◽  
For Profit ◽  
Earnings Information ◽  
Technology Firms ◽  
New Information ◽  
Over Time

SYNOPSIS: This study examines the role of revenue in valuing firms beyond earnings and investigates whether this (1) is pervasive or limited to certain situations in which earnings may be less informative, (2) is sensitive to nonlinearity in the relation between returns and earnings, and (3) has changed over time. Our analysis indicates that revenue is useful both as a summary measure for valuation purposes and in conveying new information to the market, after controlling for earnings information. These results are not driven by technology firms, extreme earnings news or loss situations, or by model misspecification because of nonlinearities. The role of revenue in firm valuation is greater, and the role of earnings is smaller, in extreme earnings situations. We also find that revenue is more useful in summarizing the performance of technology firms and for profit observations. While the combined ability of revenue and earnings to summarize contemporaneous value-relevant information has remained stable over time, the new information conveyed by earnings has declined whereas the ability of revenue to incrementally convey new information has not diminished.

scholarly journals Understanding visual attention with RAGNAROC: A Reflexive Attention Gradient through Neural AttRactOr Competition

2018 ◽  
Author(s):  
Brad Wyble ◽  
Chloe Callahan-Flintoft ◽  
Hui Chen ◽  
Toma Marinov ◽  
Aakash Sarkar ◽  
...  
Keyword(s):  
Visual Attention ◽  
Relevant Information ◽  
Neural Correlates ◽  
Neural Mechanisms ◽  
Covert Attention ◽  
Lower Priority ◽  
Reflexive Attention ◽  
Visual Hierarchy ◽  
New Information ◽  
Suppression Effects

AbstractA quintessential challenge for any perceptual system is the need to focus on task-relevant information without being blindsided by unexpected, yet important information. The human visual system incorporates several solutions to this challenge, one of which is a reflexive covert attention system that is rapidly responsive to both the physical salience and the task-relevance of new information. This paper presents a model that simulates behavioral and neural correlates of reflexive attention as the product of brief neural attractor states that are formed across the visual hierarchy when attention is engaged. Such attractors emerge from an attentional gradient distributed over a population of topographically organized neurons and serve to focus processing at one or more locations in the visual field, while inhibiting the processing of lower priority information. The model moves towards a resolution of key debates about the nature of reflexive attention, such as whether it is parallel or serial, and whether suppression effects are distributed in a spatial surround, or selectively at the location of distractors. Most importantly, the model develops a framework for understanding the neural mechanisms of visual attention as a spatiotopic decision process within a hierarchy and links them to observable correlates such as accuracy, reaction time, and the N2pc and PD components of the EEG. This last contribution is the most crucial for repairing the disconnect that exists between our understanding of behavioral and neural correlates of attention.

Dorsolateral Prefrontal Cortex Enables Updating of Established Memories

2018 ◽  
Vol 29 (10) ◽  
pp. 4154-4168 ◽  
Author(s):  
Lisa Marieke Kluen ◽  
Lisa Catherine Dandolo ◽  
Gerhard Jocham ◽  
Lars Schwabe
Keyword(s):  
Prefrontal Cortex ◽  
Dorsolateral Prefrontal Cortex ◽  
Neural Mechanisms ◽  
Related Activity ◽  
Future Behavior ◽  
New Information ◽  
Dorsolateral Prefrontal ◽  
Increased Activity ◽  
The Brain

Abstract Updating established memories in light of new information is fundamental for memory to guide future behavior. However, little is known about the brain mechanisms by which existing memories can be updated. Here, we combined functional magnetic resonance imaging and multivariate representational similarity analysis to elucidate the neural mechanisms underlying the updating of consolidated memories. To this end, participants first learned face–city name pairs. Twenty-four hours later, while lying in the MRI scanner, participants were required to update some of these associations, but not others, and to encode entirely new pairs. Updating success was tested again 24 h later. Our results showed increased activity of the dorsolateral prefrontal cortex (dlPFC) specifically during the updating of existing associations that was significantly stronger than when simple retrieval or new encoding was required. The updating-related activity of the dlPFC and its functional connectivity with the hippocampus were directly linked to updating success. Furthermore, neural similarity for updated items was markedly higher in the dlPFC and this increase in dlPFC neural similarity distinguished individuals with high updating performance from those with low updating performance. Together, these findings suggest a key role of the dlPFC, presumably in interaction with the hippocampus, in the updating of established memories.

scholarly journals The neural mechanisms of active removal from working memory

2021 ◽  
Author(s):  
Jiangang Shan ◽  
Bradley Postle
Keyword(s):  
Working Memory ◽  
Relevant Information ◽  
Neural Mechanisms ◽  
Fmri Data ◽  
Similarity Analysis ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Flexible Control ◽  
Mental Context ◽  
New Information

The ability to frequently update the contents working memory (WM) is vital for the flexible control of behavior. Whether there even exists a mechanism for the active removal of information from working memory, however, remains poorly understood. In this Registered Report we will test the predictions of models for two different (and not mutually exclusive) mechanisms of active removal: adaptation-hijacking and mental-context shifting. We will collect functional magnetic resonance imaging (fMRI) data while subjects perform a novel “ABC-retrocuing” task designed to elicit two modes of removal, active or passive (Shan & Postle, Registered Report). The adaptation-hijacking model posits an adaptation-like modification of perceptual circuits combined with a weak activation of the to-be-removed item. Its predictions will be assessed by using multivariate inverted encoding modeling (IEM) and photic “pings” to assay the state of feature-selective encoding channels and of activity-silent representations under active-removal versus passive-removal conditions. A second model – “working memory episodic memory” (WMEM) – posits that interference from no-longer-relevant information is minimized by making the mental context associated with new information dissimilar from that associated with the to-be-“removed” information. This will be tested by using representational similarity analysis (RSA) to compare the rate of contextual drift under active-removal versus passive-removal conditions.

scholarly journals Patterns of Arc mRNA expression in the rat brain following dual recall of fear- and reward-based socially acquired information

2022 ◽  
Author(s):  
Laura A Agee ◽  
Emily Nicole Hilz ◽  
Dohyun Jun ◽  
Hongjoo J Lee ◽  
Marie H Monfils
Keyword(s):  
Mrna Expression ◽  
Food Preference ◽  
Animal Species ◽  
Past Research ◽  
Neural Mechanisms ◽  
Early Gene ◽  
New Information ◽  
Brain Circuitry ◽  
Vital Component ◽  
The Brain

The ability to learn new information and behaviors is a vital component of survival in most animal species. This learning can occur via direct experience or through observation of another individual (i.e., social learning). While research focused on understanding the neural mechanisms of direct learning is prevalent, less work has aimed at understanding the brain circuitry mediating the acquisition and recall of socially acquired information. We aimed to further elucidate the mechanisms underlying recall of socially acquired information by having rats sequentially recall a socially transmitted food preference (STFP) and a fear association via fear conditioning by-proxy (FCbP). Brain tissue was processed for mRNA expression of the immediate early gene (IEG) Arc, which reliably expresses in the cell nucleus following transcription before migrating to the cytoplasm over the next 25 minutes. Given this timeframe, we were able to identify whether Arc transcription was triggered by STFP recall, FCbP recall, or following recall of both memories. Surprisingly - and contrary to past research examining expression of other IEGs following STFP or FCbP recall separately - we found no differences in any of the Arc expression measures across a number of prefrontal regions and the vCA3 of the hippocampus between controls, demonstrators, and observers, though we did detect an overall effect of sex in a number of regions. We theorize that these results may indicate that relatively little Arc-dependent neural restructuring is taking place in the prefrontal cortices following recall of a recently socially acquired information or directly acquired fear associations in these areas.

scholarly journals Dynamic updating of hippocampal object representations reflects new conceptual knowledge

2016 ◽  
Author(s):  
Michael L. Mack ◽  
Bradley C. Love ◽  
Alison R. Preston
Keyword(s):  
Conceptual Knowledge ◽  
Relevant Information ◽  
Object Representations ◽  
Imaging Data ◽  
Neural Representations ◽  
New Information ◽  
Stimulus Features ◽  
Task Goals ◽  
Dynamic Updating ◽  
The Brain

AbstractConcepts organize the relationship among individual stimuli or events by highlighting shared features. Often, new goals require updating conceptual knowledge to reflect relationships based on different goal-relevant features. Here, our aim is to determine how hippocampal (HPC) object representations are organized and updated to reflect changing conceptual knowledge. Participants learned two classification tasks in which successful learning required attention to different stimulus features, thus providing a means to index how representations of individual stimuli are reorganized according to changing task goals. We used a computational learning model to capture how people attended to goal-relevant features and organized object representations based on those features during learning. Using representational similarity analyses of functional magnetic resonance imaging data, we demonstrate that neural representations in left anterior HPC correspond with model predictions of concept organization. Moreover, we show that during early learning, when concept updating is most consequential, HPC is functionally coupled with prefrontal regions. Based on these findings, we propose that when task goals change, object representations in HPC can be organized in new ways, resulting in updated concepts that highlight the features most critical to the new goal.Significance StatementA cosmopolitan couple looking for a home may focus on trendy features. But, with news of a baby on the way, they must quickly learn which features make for a child-friendly home to conceptually reorganize their set of potential homes. Here, we investigate how conceptual knowledge is updated in the brain when goals change and attention shifts to new information. By combining fMRI with computational modeling, we find that object representations in the human hippocampus are dynamically updated with concept-relevant information during learning. We also demonstrate that when concept updating is most consequential, the hippocampus is functionally coupled with neocortex. Our findings suggest that the brain reorganizes when concepts change and provide support for a neurocomputational theory of concept formation.

scholarly journals Antagonism between brain regions relevant for cognitive control and emotional memory facilitates the generation of humorous ideas

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Florian Bitsch ◽  
Philipp Berger ◽  
Andreas Fink ◽  
Arne Nagels ◽  
Benjamin Straube ◽  
...  
Keyword(s):  
Cognitive Control ◽  
Positive Emotions ◽  
Emotional Memory ◽  
Brain Regions ◽  
Neural Mechanisms ◽  
Functional Magnetic Resonance ◽  
Frontal Brain ◽  
Successful Resolution ◽  
Neural Underpinnings ◽  
The Brain

AbstractThe ability to generate humor gives rise to positive emotions and thus facilitate the successful resolution of adversity. Although there is consensus that inhibitory processes might be related to broaden the way of thinking, the neural underpinnings of these mechanisms are largely unknown. Here, we use functional Magnetic Resonance Imaging, a humorous alternative uses task and a stroop task, to investigate the brain mechanisms underlying the emergence of humorous ideas in 24 subjects. Neuroimaging results indicate that greater cognitive control abilities are associated with increased activation in the amygdala, the hippocampus and the superior and medial frontal gyrus during the generation of humorous ideas. Examining the neural mechanisms more closely shows that the hypoactivation of frontal brain regions is associated with an hyperactivation in the amygdala and vice versa. This antagonistic connectivity is concurrently linked with an increased number of humorous ideas and enhanced amygdala responses during the task. Our data therefore suggests that a neural antagonism previously related to the emergence and regulation of negative affective responses, is linked with the generation of emotionally positive ideas and may represent an important neural pathway supporting mental health.

scholarly journals Safety of Catheter Embolization of Pulmonary Arteriovenous Malformations—Evaluation of Possible Cerebrovascular Embolism after Catheter Embolization of Pulmonary Arteriovenous Malformations in Patients with Hereditary Hemorrhagic Telangiectasia/Osler Disease by Pre- and Post-Interventional DWI

2021 ◽  
Vol 10 (4) ◽  
pp. 887
Author(s):  
Guenther Schneider ◽  
Alexander Massmann ◽  
Peter Fries ◽  
Felix Frenzel ◽  
Arno Buecker ◽  
...  
Keyword(s):  
Arteriovenous Malformations ◽  
Pulmonary Arteriovenous Malformations ◽  
B Values ◽  
Safe Method ◽  
Embolization Therapy ◽  
Catheter Embolization ◽  
Contrast Enhanced ◽  
Previously Treated ◽  
The Brain ◽  
Over Time

Background. This paper aimed to prospectively evaluate the safety of embolization therapy of pulmonary arteriovenous malformations (PAVMs) for the detection of cerebral infarctions by pre- and post-interventional MRI. Method One hundred and five patients (male/female = 44/61; mean age 48.6+/−15.8; range 5–86) with pre-diagnosed PAVMs on contrast-enhanced MRA underwent embolization therapy. The number of PAVMs treated in each patient ranged from 1–8 PAVMs. Depending on the size and localization of the feeding arteries, either Nester-Coils or Amplatzer vascular plugs were used for embolization therapy. cMRI was performed immediately before, and at the 4 h and 3-month post-embolization therapy. Detection of peri-interventional cerebral emboli was performed via T2w and DWI sequences using three different b-values, with calculation of ADC maps. Results Embolization did not show any post-/peri-interventional, newly developed ischemic lesions in the brain. Only one patient who underwent re-embolization and was previously treated with tungsten coils that corroded over time showed newly developed, small, diffuse emboli in the post-interventional DWI sequence. This patient already had several episodes of brain emboli before re-treatment due to the corroded coils, and during treatment, when passing the corroded coils, experienced additional small, clinically inconspicuous brain emboli. However, this complication was anticipated but accepted, since the vessel had to be occluded distally. Conclusion Catheter-based embolization of PAVMs is a safe method for treatment and does not result in clinically inconspicuous cerebral ischemia, which was not demonstrated previously.

Sources of the Scalp-Recorded Amplitude-Modulation Following Response

2002 ◽  
Vol 13 (04) ◽  
pp. 188-204 ◽  
Author(s):  
Shigeyuki Kuwada ◽  
Julia S. Anderson ◽  
Ranjan Batra ◽  
Douglas C. Fitzpatrick ◽  
Natacha Teissier ◽  
...  
Keyword(s):  
Animal Model ◽  
Amplitude Modulation ◽  
Single Unit ◽  
Modulation Frequency ◽  
Multiple Sources ◽  
High Modulation ◽  
Before And After ◽  
Single Unit Recordings ◽  
Composite Response ◽  
The Brain

The scalp-recorded amplitude-modulation following response (AMFR)” is gaining recognition as an objective audiometric tool, but little is known about the neural sources that underlie this potential. We hypothesized, based on our human studies and single-unit recordings in animals, that the scalp-recorded AMFR reflects the interaction of multiple sources. We tested this hypothesis using an animal model, the unanesthetized rabbit. We compared AMFRs recorded from the surface of the brain at different locations and before and after the administration of agents likely to enhance or suppress neural generators. We also recorded AMFRs locally at several stations along the auditory neuraxis. We conclude that the surface-recorded AMFR is indeed a composite response from multiple brain generators. Although the response at any modulation frequency can reflect the activity of more than one generator, the AMFRs to low and high modulation frequencies appear to reflect a strong contribution from cortical and subcortical sources, respectively.

scholarly journals Cognitive Control of Working Memory: A Model-Based Approach

2021 ◽  
Vol 11 (6) ◽  
pp. 721
Author(s):  
Russell J. Boag ◽  
Niek Stevenson ◽  
Roel van Dooren ◽  
Anne C. Trutti ◽  
Zsuzsika Sjoerds ◽  
...  
Keyword(s):  
Decision Making ◽  
Working Memory ◽  
Cognitive Control ◽  
Relevant Information ◽  
Decision Time ◽  
Control Processes ◽  
Prepotent Response ◽  
New Information ◽  
Empirical Performance ◽  
Flow Of Information

Working memory (WM)-based decision making depends on a number of cognitive control processes that control the flow of information into and out of WM and ensure that only relevant information is held active in WM’s limited-capacity store. Although necessary for successful decision making, recent work has shown that these control processes impose performance costs on both the speed and accuracy of WM-based decisions. Using the reference-back task as a benchmark measure of WM control, we conducted evidence accumulation modeling to test several competing explanations for six benchmark empirical performance costs. Costs were driven by a combination of processes, running outside of the decision stage (longer non-decision time) and showing the inhibition of the prepotent response (lower drift rates) in trials requiring WM control. Individuals also set more cautious response thresholds when expecting to update WM with new information versus maintain existing information. We discuss the promise of this approach for understanding cognitive control in WM-based decision making.

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