scholarly journals Dynamically structured holographic memory

2019 ◽  
Author(s):  
Matthew Rutledge-Taylor ◽  
Matthew A Kelly ◽  
Robert West ◽  
Aryn Pyke
Keyword(s):  
Declarative Memory ◽  
Scale Up ◽  
Dynamic Game ◽  
Human Memory ◽  
Problem Size ◽  
Holographic Memory ◽  
Sequential Dependencies ◽  
Fan Effect ◽  
Problem Size Effect ◽  
The Relationship

We describe the DSHM (Dynamically Structured Holographic Memory) model of human memory, which uses high dimensional vectors to represent items in memory. The complexity and intelligence of human behavior can be attributed, in part, to our ability to utilize vast knowledge acquired over a lifetime of experience with our environment. Thus models of memory, particularly models that can scale up to lifetime learning, are critical to modeling human intelligence. DHSM is based on the BEAGLE model of language acquisition (Jones and Mewhort, 2007) and extends this type of model to general memory phenomena. We demonstrate that DHSM can model a wide variety of human memory effects. Specifically, we model the fan effect, the problem size effect (from math cognition), dynamic game playing (detecting sequential dependencies from memories of past moves), and time delay learning (using an instance based approach). This work suggests that DSHM is suitable as a basis for learning both over the short-term and over the lifetime of the agent, and as a basis for both procedural and declarative memory. We argue that cognition needs to be understood at both the symbolic and sub-symbolic levels, and demonstrate that DSHM intrinsically operates at both of these levels of description. In order to situate DSHM in a familiar context, we discuss the relationship between DHSM and ACT-R.

scholarly journals 0084 Sleep Consolidates Incidentally Encoded Information After Deep but Not Shallow Encoding

SLEEP ◽  
2020 ◽  
Vol 43 (Supplement_1) ◽  
pp. A34-A34
Author(s):  
E M Wernette ◽  
K M Fenn
Keyword(s):  
Slow Wave ◽  
Memory Consolidation ◽  
Slow Wave Sleep ◽  
Declarative Memory ◽  
Memory Performance ◽  
Memory Test ◽  
Memory Traces ◽  
Incidental Encoding ◽  
The Relationship ◽  
With Memory

Abstract Introduction Slow wave sleep (SWS) strengthens declarative memory for information studied for a later test. However, research on the effect of sleep on information that is not intentionally remembered is scare. Previous research from our lab suggests sleep consolidates some, but not all, information that has been encoded incidentally, meaning that it has been acted on but not intentionally remembered. It remains unclear what determines which information benefits from sleep-dependent consolidation processes and what aspects of sleep are related to these mnemonic benefits. In two experiments, we test the hypothesis that sleep consolidates strong but not weak memory traces following incidental encoding, and assess the relationship between memory performance and objective sleep characteristics. Methods In Experiment 1, participants rated words one (weak traces) or three times (strong traces) in a deep or shallow incidental encoding task. Participants either rated words on a scale from ‘concrete’ to ‘abstract’ (deep) or counted the vowels in the words (shallow). Following a 12-hour period containing sleep or wakefulness, participants took a surprise memory test. In Experiment 2, participants rated words one or three times in the deep encoding task, received an 8-hour sleep opportunity with polysomnography, and took the surprise memory test. Results In Experiment 1, participants remembered words better after sleep than wake regardless of whether words were encoded one or three times, but only after deep encoding. Sleep did not consolidate information following shallow encoding. Experiment 2 is ongoing, but we predict that the amount of SWS will correlate positively with memory. Conclusion Results thus far suggest sleep may have consolidated information based on the strength of memory traces. Because deep encoding results in stronger memory traces than shallow encoding, this work is broadly consistent with theories of memory consolidation that predict sleep is more beneficial for strong memory traces than weak, such as the synaptic downscaling hypothesis. Support N/A

scholarly journals Brain Mechanisms of Arithmetic: A Crucial Role for Ventral Temporal Cortex

2018 ◽  
Vol 30 (12) ◽  
pp. 1757-1772 ◽  
Author(s):  
Pedro Pinheiro-Chagas ◽  
Amy Daitch ◽  
Josef Parvizi ◽  
Stanislas Dehaene
Keyword(s):  
Numerical Cognition ◽  
Parietal Lobe ◽  
Temporal Cortex ◽  
Classical Problem ◽  
Brain Regions ◽  
Inferior Temporal Cortex ◽  
Problem Size ◽  
Ventral Temporal Cortex ◽  
Intracranial Electroencephalography ◽  
Problem Size Effect

Elementary arithmetic requires a complex interplay between several brain regions. The classical view, arising from fMRI, is that the intraparietal sulcus (IPS) and the superior parietal lobe (SPL) are the main hubs for arithmetic calculations. However, recent studies using intracranial electroencephalography have discovered a specific site, within the posterior inferior temporal cortex (pITG), that activates during visual perception of numerals, with widespread adjacent responses when numerals are used in calculation. Here, we reexamined the contribution of the IPS, SPL, and pITG to arithmetic by recording intracranial electroencephalography signals while participants solved addition problems. Behavioral results showed a classical problem size effect: RTs increased with the size of the operands. We then examined how high-frequency broadband (HFB) activity is modulated by problem size. As expected from previous fMRI findings, we showed that the total HFB activity in IPS and SPL sites increased with problem size. More surprisingly, pITG sites showed an initial burst of HFB activity that decreased as the operands got larger, yet with a constant integral over the whole trial, thus making these signals invisible to slow fMRI. Although parietal sites appear to have a more sustained function in arithmetic computations, the pITG may have a role of early identification of the problem difficulty, beyond merely digit recognition. Our results ask for a reevaluation of the current models of numerical cognition and reveal that the ventral temporal cortex contains regions specifically engaged in mathematical processing.

Higher cognitive functions: memory and reasoning

2012 ◽  
Author(s):  
Simone Rossi ◽  
Stefano F. Cappa ◽  
Paolo Maria Rossini
Keyword(s):  
Cognitive Functions ◽  
Declarative Memory ◽  
Human Memory ◽  
Short Term ◽  
Physiological Mechanisms ◽  
Higher Cognitive Functions ◽  
Methodological Considerations ◽  
Nonverbal Reasoning ◽  
Interference Studies ◽  
Single Technique

Transcranial magnetic stimulation (TMS) is a sophisticated approach for interfering with human memory and reasoning due to its ability to transiently interfere with the functions of the specialized cortical network, especially when applied as repetitive (r)TMS. This article reviews TMS studies dealing with short-term retention, working memory, and with the episodic component of declarative memory. It also considers certain aspects of semantic memory and nonverbal reasoning. Furthermore, it discusses methodological considerations about the experimental designs, which can be used for the investigation of human cognitive functions. This article emphasizes the fact that higher cognitive functions provide an example as to how underlying physiological mechanisms cannot be fully disclosed by investigations based on a single technique. Studies to develop a true multimodal approach are being undertaken. In this light, behavioural interference studies will gain new power in combination with disruptive and correlational methodologies, establishing causality in a more sophisticated manner.

Electric Field and Spinning Performance in Needleless Electrospinning

2014 ◽  
Vol 1048 ◽  
pp. 26-30 ◽  
Author(s):  
Xin Wang ◽  
Yuan Zhao ◽  
Hao Wang ◽  
Guang Ming Cai
Keyword(s):  
Experimental Investigation ◽  
Electric Field ◽  
Scale Up ◽  
Key Factors ◽  
Needleless Electrospinning ◽  
Modeling Analysis ◽  
Experimental Parameters ◽  
Spun Fiber ◽  
The Relationship

Different spinnerets can be used to generate needleless electrospinning with the potential to scale up the production of nanofibers. However, the electrospinning performance, normally refers to the quality of the as-spun fiber and the production rate, is dramatically different from different spinnerets. This study focuses on the electric field of different spinnerets under the same experimental parameters so as to understand the key factors that affect the electrospinning performance of upward needleless electrospinning. Modeling analysis suggested that the electric field could be further concentrated by optimizing the geometry of spinneret. Experimental investigation on needleless electrospinning from different spinnerets proved that the electrospinning performance was improved greatly with the optimization of the electric field of spinneret. Understanding of the relationship between electric field and spinning performance would benefit the design and development of needleless electrospinning.

scholarly journals Frontal Cognitive Function and Memory in Parkinson’s Disease: Toward a Distinction between Prospective and Declarative Memory Impairments?

1995 ◽  
Vol 8 (2) ◽  
pp. 59-74 ◽  
Author(s):  
A. I. Tröster ◽  
J. A. Fields
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Memory Impairment ◽  
Declarative Memory ◽  
Empirical Support ◽  
Cognitive Mechanisms ◽  
Memory Dysfunction ◽  
Memory Impairments ◽  
Executive Deficits ◽  
The Relationship

Memory dysfunction is a frequent concomitant of Parkinson's disease (PD). Historically, two classes of hypotheses, focusing on different cognitive mechanisms, have been advanced to explain this memory impairment: one postulating retrieval deficits (common to several neurodegenerative disorders involving the basal ganglia), and the other postulating frontally mediated executive deficits as fundamental to memory impairment. After outlining empirical support for the retrieval deficit hypothesis, research on the more recent “frontal executive deficit hypothesis” is reviewed, and major challenges to this hypothesis are identified. It is concluded that the frontal executive deficit hypothesis cannot adequately account for all memory impairments in PD, and that a more parsimonious theoretical account might invoke a distinction between prospective and declarative memory impairments. It is suggested that there may be three subgroups of PD patients: one demonstrating prospective memory dysfunction only, one with declarative memory dysfunction only, and one with both prospective and declarative memory dysfunction. Consequently, PD might provide a useful model within which to investigate the relationship between prospective and declarative memory.

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