Design and measurement of fully digital ternary content addressable memory using ratioless static random access memory cells and hierarchical-AND matching comparator

Science.gov (United States)

Nishikata, Daisuke; Ali, Mohammad Alimudin Bin Mohd; Hosoda, Kento; Matsumoto, Hiroshi; Nakamura, Kazuyuki

2018-04-01

A 36-bit × 32-entry fully digital ternary content addressable memory (TCAM) using the ratioless static random access memory (RL-SRAM) technology and fully complementary hierarchical-AND matching comparators (HAMCs) was developed. Since its fully complementary and digital operation enables the effect of device variabilities to be avoided, it can operate with a quite low supply voltage. A test chip incorporating a conventional TCAM and a proposed 24-transistor ratioless TCAM (RL-TCAM) cells and HAMCs was developed using a 0.18 µm CMOS process. The minimum operating voltage of 0.25 V of the developed RL-TCAM, which is less than half of that of the conventional TCAM, was measured via the conventional CMOS push–pull output buffers with the level-shifting and flipping technique using optimized pull-up voltage and resistors.

A content addressable memory for use in CEBAF's CLAS detector level 2 triggering system

International Nuclear Information System (INIS)

Hodson, R.F.; Doughty, D.C. Jr.; Allgood, D.C.; Campbell, S.A.; Wilson, W.C.; Bickley, M.H.

1996-01-01

A collaboration of researchers from CEBAF, CNU and NASA is designing a 256-32 specialized Content Addressable Memory (CAM) for the level 2 triggering system in CEBAF's CLAS detector. These integrated circuits will find tracks and the momentum and angle of each track within 2 microseconds of an event. The custom CAM can operate as conventional memory, performing read and write operations, and can additionally perform independent byte compare operations across all words simultaneously. It is this compare feature which makes these CAMs attractive for identifying tracks passing through drift chambers by linking together segment number triplets within the CAM. Simulations have indicated that less than 16 k triplets need to be stored for each sector of the detector. This implies the level 2 triggering can be performed with 64 CAM chips per sector, or 384 total. Each data channel into a sector CAM array is buffered in a FIFO and is designed to handle aggregate data rates up to 750 Mbs for three channels (one channel/superlayer). The architecture of the level 2 trigger and details of the CAM chip design are discussed along with a performance report on our prototype CAMs

Comparison Elements on STG DICE cell for Content-Addressable Memory and Simulation of Single-Event Transients

Directory of Open Access Journals (Sweden)

V. Ya. Stenin

2017-06-01

Full Text Available Comparison elements on base the STG DICE cell and the logical element “Exclusive OR” for a content-addressable memory were designed and simulated. The comparison element contains two identical joint groups of transistors that are spaced on the chip by the distance of four micrometers, so the loss of data in STG DICE cell practically excluded. On the characteristics of the new 65-nm CMOS comparison element, we predict the hardness of these item to single event rate (SER more to hundred times compared to elements on 6-transistors cells and the standard DICE cell with distances 0.5-0.6 μm between mutually sensitive nodes.

A novel match-line selective charging scheme for high-speed, low-power and noise-tolerant content-addressable memory

KAUST Repository

Hasan, Muhammad Mubashwar; Rashid, Abdul B M Harun Ur; Hussain, Muhammad Mustafa

2010-01-01

Content-addressable memory (CAM) is an essential component for high-speed lookup intensive applications. This paper presents a match-line selective charging technique to increase speed and reduce the energy per bit per search while increasing the noise-tolerance. Simulation in TSMC 0.18 μm technology with 64×72 Ternary CAM shows the match-line energy reduction of 45% compared to the conventional currentsaving scheme with the reduction of minimum cycle time by 68% and the improvement of noise-tolerance by 96%.

A novel match-line selective charging scheme for high-speed, low-power and noise-tolerant content-addressable memory

KAUST Repository

Hasan, Muhammad Mubashwar

2010-06-01

Content-addressable memory (CAM) is an essential component for high-speed lookup intensive applications. This paper presents a match-line selective charging technique to increase speed and reduce the energy per bit per search while increasing the noise-tolerance. Simulation in TSMC 0.18 μm technology with 64×72 Ternary CAM shows the match-line energy reduction of 45% compared to the conventional currentsaving scheme with the reduction of minimum cycle time by 68% and the improvement of noise-tolerance by 96%.

Zone memories and pseudorandom addressing

International Nuclear Information System (INIS)

Marino, D.; Mirizzi, N.; Stella, R.; Visaggio, G.

1975-01-01

A quantitative comparison between zone memories, pseudorandom addressed memories and an alternative special purpose memory (spread zone memory) in which the distance between any two transformed descriptors, at first adjacent, is independent of the descriptors pair and results the maximum one is presented. This memory has not been particularly considered at present in spite of its efficiency and its simple implementation

Analysis of the influence of memory content of auditory stimuli on the memory content of EEG signal.

Science.gov (United States)

Namazi, Hamidreza; Khosrowabadi, Reza; Hussaini, Jamal; Habibi, Shaghayegh; Farid, Ali Akhavan; Kulish, Vladimir V

2016-08-30

One of the major challenges in brain research is to relate the structural features of the auditory stimulus to structural features of Electroencephalogram (EEG) signal. Memory content is an important feature of EEG signal and accordingly the brain. On the other hand, the memory content can also be considered in case of stimulus. Beside all works done on analysis of the effect of stimuli on human EEG and brain memory, no work discussed about the stimulus memory and also the relationship that may exist between the memory content of stimulus and the memory content of EEG signal. For this purpose we consider the Hurst exponent as the measure of memory. This study reveals the plasticity of human EEG signals in relation to the auditory stimuli. For the first time we demonstrated that the memory content of an EEG signal shifts towards the memory content of the auditory stimulus used. The results of this analysis showed that an auditory stimulus with higher memory content causes a larger increment in the memory content of an EEG signal. For the verification of this result, we benefit from approximate entropy as indicator of time series randomness. The capability, observed in this research, can be further investigated in relation to human memory.

Contention Modeling for Multithreaded Distributed Shared Memory Machines: The Cray XMT

Energy Technology Data Exchange (ETDEWEB)

Secchi, Simone; Tumeo, Antonino; Villa, Oreste

2011-07-27

Distributed Shared Memory (DSM) machines are a wide class of multi-processor computing systems where a large virtually-shared address space is mapped on a network of physically distributed memories. High memory latency and network contention are two of the main factors that limit performance scaling of such architectures. Modern high-performance computing DSM systems have evolved toward exploitation of massive hardware multi-threading and fine-grained memory hashing to tolerate irregular latencies, avoid network hot-spots and enable high scaling. In order to model the performance of such large-scale machines, parallel simulation has been proved to be a promising approach to achieve good accuracy in reasonable times. One of the most critical factors in solving the simulation speed-accuracy trade-off is network modeling. The Cray XMT is a massively multi-threaded supercomputing architecture that belongs to the DSM class, since it implements a globally-shared address space abstraction on top of a physically distributed memory substrate. In this paper, we discuss the development of a contention-aware network model intended to be integrated in a full-system XMT simulator. We start by measuring the effects of network contention in a 128-processor XMT machine and then investigate the trade-off that exists between simulation accuracy and speed, by comparing three network models which operate at different levels of accuracy. The comparison and model validation is performed by executing a string-matching algorithm on the full-system simulator and on the XMT, using three datasets that generate noticeably different contention patterns.

Memory reconsolidation mediates the updating of hippocampal memory content

Directory of Open Access Journals (Sweden)

Jonathan L C Lee

2010-11-01

Full Text Available The retrieval or reactivation of a memory places it into a labile state, requiring a process of reconsolidation to restabilize it. This retrieval-induced plasticity is a potential mechanism for the modification of the existing memory. Following previous data supportive of a functional role for memory reconsolidation in the modification of memory strength, here I show that hippocampal memory reconsolidation also supports the updating of contextual memory content. Using a procedure that separates the learning of pure context from footshock-motivated contextual fear learning, I demonstrate doubly dissociable hippocampal mechanisms of initial context learning and subsequent updating of the neutral contextual representation to incorporate the footshock. Contextual memory consolidation was dependent upon BDNF expression in the dorsal hippocampus, whereas the footshock modification of the contextual representation required the expression of Zif268. These mechanisms match those previously shown to be selectively involved in hippocampal memory consolidation and reconsolidation, respectively. Moreover, memory reactivation is a necessary step in modifying memory content, as inhibition of hippocampal synaptic protein degradation also prevented the footshock-mediated memory modification. Finally, dorsal hippocampal knockdown of Zif268 impaired the reconsolidation of the pure contextual memory only under conditions of weak context memory training, as well as failing to disrupt contextual freezing when a strong contextual fear memory is reactivated by further conditioning. Therefore, an adaptive function of the reactivation and reconsolidation process is to enable the updating of memory content.

Dissociating Contents of Consciousness from Contents of Short-Term Memory

DEFF Research Database (Denmark)

Sørensen, Thomas Alrik; Ásgeirsson, Árni Gunnar; Staugaard, Camilla Funch

2014-01-01

The contents of consciousness and of short-term memory are hard to disentangle. As it seems intuitive that we represent attended objects in short-term memory and in experience, to many, it also seems intuitive to equate this content. Here we investigated memory resolution for orientation......” to a “clear experience” of a probed target. To assess memory resolution we used a Landolt-variation on the visual short-term memory (VSTM) resolution paradigm (e.g. Wilken & Ma, 2004). Set-sizes in the memory display were varied between 1, 2, or 4 elements. With increasing set-size we found that both...

Quantitative measurements of autobiographical memory content.

Directory of Open Access Journals (Sweden)

Robert S Gardner

Full Text Available Autobiographical memory (AM, subjective recollection of past experiences, is fundamental in everyday life. Nevertheless, characterization of the spontaneous occurrence of AM, as well as of the number and types of recollected details, remains limited. The CRAM (Cue-Recalled Autobiographical Memory test (http://cramtest.info adapts and combines the cue-word method with an assessment that collects counts of details recalled from different life periods. The SPAM (Spontaneous Probability of Autobiographical Memories protocol samples introspection during everyday activity, recording memory duration and frequency. These measures provide detailed, naturalistic accounts of AM content and frequency, quantifying essential dimensions of recollection. AM content (∼20 details/recollection decreased with the age of the episode, but less drastically than the probability of reporting remote compared to recent memories. AM retrieval was frequent (∼20/hour, each memory lasting ∼30 seconds. Testable hypotheses of the specific content retrieved in a fixed time from given life periods are presented.

Memory reconsolidation mediates the updating of hippocampal memory content

OpenAIRE

Jonathan L C Lee

2010-01-01

The retrieval or reactivation of a memory places it into a labile state, requiring a process of reconsolidation to restabilize it. This retrieval-induced plasticity is a potential mechanism for the modification of the existing memory. Following previous data supportive of a functional role for memory reconsolidation in the modification of memory strength, here I show that hippocampal memory reconsolidation also supports the updating of contextual memory content. Using a procedure that se...

Memory Compression Techniques for Network Address Management in MPI

Energy Technology Data Exchange (ETDEWEB)

Guo, Yanfei; Archer, Charles J.; Blocksome, Michael; Parker, Scott; Bland, Wesley; Raffenetti, Ken; Balaji, Pavan

2017-05-29

MPI allows applications to treat processes as a logical collection of integer ranks for each MPI communicator, while internally translating these logical ranks into actual network addresses. In current MPI implementations the management and lookup of such network addresses use memory sizes that are proportional to the number of processes in each communicator. In this paper, we propose a new mechanism, called AV-Rankmap, for managing such translation. AV-Rankmap takes advantage of logical patterns in rank-address mapping that most applications naturally tend to have, and it exploits the fact that some parts of network address structures are naturally more performance critical than others. It uses this information to compress the memory used for network address management. We demonstrate that AV-Rankmap can achieve performance similar to or better than that of other MPI implementations while using significantly less memory.

Emotion and false memory: The context-content paradox.

Science.gov (United States)

Bookbinder, S H; Brainerd, C J

2016-12-01

False memories are influenced by a variety of factors, but emotion is a variable of special significance, for theoretical and practical reasons. Interestingly, emotion's effects on false memory depend on whether it is embedded in the content of to-be-remembered events or in our moods, where mood is an aspect of the context in which events are encoded. We sketch the theoretical basis for this content-context dissociation and then review accumulated evidence that content and context effects are indeed different. Paradoxically, we find that in experiments on spontaneous and implanted false memories, negatively valenced content foments distortion, but negatively valenced moods protect against it. In addition, correlational data show that enduring negative natural moods (e.g., depression) foment false memory. Current opponent-process models of false memory, such as fuzzy-trace theory, are able to explain the content-context dissociation: Variations in emotional content primarily affect memory for the gist of events, whereas variations in emotional context primarily affect memory for events' exact verbatim form. Important questions remain about how these effects are modulated by variations in memory tests and in arousal. Promising methods of tackling those questions are outlined, especially designs that separate the gist and verbatim influences of emotion. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Reprogrammable read only variable threshold transistor memory with isolated addressing buffer

Science.gov (United States)

Lodi, Robert J.

1976-01-01

A monolithic integrated circuit, fully decoded memory comprises a rectangular array of variable threshold field effect transistors organized into a plurality of multi-bit words. Binary address inputs to the memory are decoded by a field effect transistor decoder into a plurality of word selection lines each of which activates an address buffer circuit. Each address buffer circuit, in turn, drives a word line of the memory array. In accordance with the word line selected by the decoder the activated buffer circuit directs reading or writing voltages to the transistors comprising the memory words. All of the buffer circuits additionally are connected to a common terminal for clearing all of the memory transistors to a predetermined state by the application to the common terminal of a large magnitude voltage of a predetermined polarity. The address decoder, the buffer and the memory array, as well as control and input/output control and buffer field effect transistor circuits, are fabricated on a common substrate with means provided to isolate the substrate of the address buffer transistors from the remainder of the substrate so that the bulk clearing function of simultaneously placing all of the memory transistors into a predetermined state can be performed.

Medial temporal lobe reinstatement of content-specific details predicts source memory

Science.gov (United States)

Liang, Jackson C.; Preston, Alison R.

2016-01-01

Leading theories propose that when remembering past events, medial temporal lobe (MTL) structures reinstate the neural patterns that were active when those events were initially encoded. Accurate reinstatement is hypothesized to support detailed recollection of memories, including their source. While several studies have linked cortical reinstatement to successful retrieval, indexing reinstatement within the MTL network and its relationship to memory performance has proved challenging. Here, we addressed this gap in knowledge by having participants perform an incidental encoding task, during which they visualized people, places, and objects in response to adjective cues. During a surprise memory test, participants saw studied and novel adjectives and indicated the imagery task they performed for each adjective. A multivariate pattern classifier was trained to discriminate the imagery tasks based on functional magnetic resonance imaging (fMRI) responses from hippocampus and MTL cortex at encoding. The classifier was then tested on MTL patterns during the source memory task. We found that MTL encoding patterns were reinstated during successful source retrieval. Moreover, when participants made source misattributions, errors were predicted by reinstatement of incorrect source content in MTL cortex. We further observed a gradient of content-specific reinstatement along the anterior-posterior axis of hippocampus and MTL cortex. Within anterior hippocampus, we found that reinstatement of person content was related to source memory accuracy, whereas reinstatement of place information across the entire hippocampal axis predicted correct source judgments. Content-specific reinstatement was also graded across MTL cortex, with PRc patterns evincing reactivation of people and more posterior regions, including PHc, showing evidence for reinstatement of places and objects. Collectively, these findings provide key evidence that source recollection relies on reinstatement of past

A diagonal address generator for a Josephson memory circuit

International Nuclear Information System (INIS)

Suzuki, H.; Hasuo, S.

1987-01-01

The authors propose that a diagonal D address generator, which is useful for a single flux quantum (SFQ) memory cell in the triple coincidence scheme, can be performed by a full adder circuit. For the purpose of evaluating the D address generator for a 16-kbit memory circuit, a 6-bit full adder circuit, using a current-steering flip-flop circuit, has been designed and fabricated with the lead-alloy process. Operating times for the address latch, carry generator, and sum generator were 150 ps, 250 ps/stage, and 1.4 ns, respectively. From these results, they estimate that the time necessary for the diagonal signal generation is 2.8 ns

A flexible analog memory address list manager for PHENIX

International Nuclear Information System (INIS)

Ericson, M.N.; Musrock, M.S.; Britton, C.L. Jr.; Walker, J.W.; Wintenberg, A.L.; Young, G.R.; Allen, M.D.

1996-01-01

A programmable analog memory address list manager has been developed for use with all analog memory-based detector subsystems of PHENIX. The unit provides simultaneous read/write control, cell write-over protection for both a Level-1 trigger decision delay and digitization latency, and re-ordering of AMU addresses following conversion, at a beam crossing rate of 105 ns. Addresses are handled such that up to 5 Level-1 (LVL-1) events can be maintained in the AMU without write-over. Data tagging is implemented for handling overlapping and shared beam-event data packets. Full usage in all PHENIX analog memory-based detector subsystems is accomplished by the use of detector-specific programmable parameters--the number of data samples per valid LVL-1 trigger and the sample spacing. Architectural candidates for the system are discussed with emphasis on implementation implications. Details of the design are presented including application specifics, timing information, and test results from a full implementation using field programmable gate arrays (FPGAs)

Short-term memory for scenes with affective content

OpenAIRE

Maljkovic, Vera; Martini, Paolo

2005-01-01

The emotional content of visual images can be parameterized along two dimensions: valence (pleasantness) and arousal (intensity of emotion). In this study we ask how these distinct emotional dimensions affect the short-term memory of human observers viewing a rapid stream of images and trying to remember their content. We show that valence and arousal modulate short-term memory as independent factors. Arousal influences dramatically the average speed of data accumulation in memory: Higher aro...

PCI bus content-addressable-memory (CAM) implementation on FPGA for pattern recognition/image retrieval in a distributed environment

Science.gov (United States)

Megherbi, Dalila B.; Yan, Yin; Tanmay, Parikh; Khoury, Jed; Woods, C. L.

2004-11-01

Recently surveillance and Automatic Target Recognition (ATR) applications are increasing as the cost of computing power needed to process the massive amount of information continues to fall. This computing power has been made possible partly by the latest advances in FPGAs and SOPCs. In particular, to design and implement state-of-the-Art electro-optical imaging systems to provide advanced surveillance capabilities, there is a need to integrate several technologies (e.g. telescope, precise optics, cameras, image/compute vision algorithms, which can be geographically distributed or sharing distributed resources) into a programmable system and DSP systems. Additionally, pattern recognition techniques and fast information retrieval, are often important components of intelligent systems. The aim of this work is using embedded FPGA as a fast, configurable and synthesizable search engine in fast image pattern recognition/retrieval in a distributed hardware/software co-design environment. In particular, we propose and show a low cost Content Addressable Memory (CAM)-based distributed embedded FPGA hardware architecture solution with real time recognition capabilities and computing for pattern look-up, pattern recognition, and image retrieval. We show how the distributed CAM-based architecture offers a performance advantage of an order-of-magnitude over RAM-based architecture (Random Access Memory) search for implementing high speed pattern recognition for image retrieval. The methods of designing, implementing, and analyzing the proposed CAM based embedded architecture are described here. Other SOPC solutions/design issues are covered. Finally, experimental results, hardware verification, and performance evaluations using both the Xilinx Virtex-II and the Altera Apex20k are provided to show the potential and power of the proposed method for low cost reconfigurable fast image pattern recognition/retrieval at the hardware/software co-design level.

Ritual as a method of social memory content transfer

Directory of Open Access Journals (Sweden)

Utkina Anna N.

2016-01-01

Full Text Available The paper deals with a ritual as a method of social memory content transfer. To reveal dialectics of ritual phenomenon formation and development, hermeneutical, dialectical and general scientific approaches as well as analysis and synthesis are applied. Social memory is considered as a complex of essential information for a society rooted in a social medium mentality and transferred from one generation to another. In terms of analyzed theoretical approaches to ritual and social memory the authors conclude that a ritual is capable of transferring social memory from one social stratum to another retaining its content. By means of a ritual, the process of conversation between different individuals is implemented, and the unity of memories is formed. Ritual instability allows changing its form dialectically retaining its content unvaried. Ritual preserves, presents and keeps its content current taking into account changing forms of manifestation that define the dynamics of society development. Reflecting the inner content of a social memory ritual contributes to its literal perception in the modern world and, as a consequence, to the reduction of social conscience manipulation. The development of society is in great necessity in such methods of social memory transfer that are capable of responding to social changes retaining important information for society ungarbled. The authors consider a ritual as one of such methods.

A flexible analog memory address list manager/controller for PHENIX

International Nuclear Information System (INIS)

Ericson, M.N.; Walker, J.W.; Britton, C.L.; Wintenberg, A.L.; Young, G.R.

1995-01-01

A programmable analog memory address list manager/controller has been developed for use with all analog memory-based detector subsystems of PHENIX. The unit provides simultaneous read/write control, cell write-over protection for both a Level-1 trigger decision delay and digitization latency, and re-ordering of AMU addresses following conversion, at a beam crossing rate of 112 ns. Addresses are handled such that up to 5 Level-1 events can be maintained in the AMU without write-over. Data tagging is implemented for handling overlapping and shared beam event data packets. Full usage in all PHENIX analog memory-based detector sub-systems is accomplished by the use of detector-specific programmable parameters -- the number of data samples per Level-1 trigger valid and the swnple spacing. Architectural candidates for the system are discussed with emphasis on implementation implications. Details of the design are presented including design simulations, timing information, and test results from a full implementation using programmable logic devices

Working memory contents revive the neglected, but suppress the inhibited.

Science.gov (United States)

Han, Suk Won

2015-12-01

It is well known that attention is biased toward a stimulus matching working memory contents. However, it remains unknown whether the maintenance of information in working memory by itself is sufficient to create memory-driven attentional capture. Notably, in many previous studies showing the memory-driven attentional capture, the task settings might have explicitly or implicitly incentivized participants to strategically attend to a memory-matching stimulus. By innovating an experimental paradigm, the present study overcame this challenge and directly tested whether working memory contents capture attention in the absence of task-level attentional bias toward a memory-matching stimulus. I found that a stimulus that is usually outside the focus of attention, powerfully captured attention when it matched working memory contents, whereas a match between working memory and an inhibited stimulus suppressed attentional allocation toward the memory-matching stimulus. These findings suggest that in the absence of any task-level attentional bias toward memory-matching stimuli, attention is biased toward a memory-matching stimulus, but this memory-driven attentional capture is diminished when top-down inhibition is imposed on the stimulus. Copyright © 2015 Elsevier B.V. All rights reserved.

Content-specific working memory modulation of the attentional blink

NARCIS (Netherlands)

Akyürek, Elkan G.; Abedian-Amiri, Ali; Ostermeier, Sonja M.

2011-01-01

Three experiments were conducted to investigate the effects of working memory content on temporal attention in a rapid serial visual presentation attentional blink paradigm. It was shown that categorical similarity between working memory content and the target stimuli pertaining to the attentional

Compelling Untruths: Content Borrowing and Vivid False Memories

Science.gov (United States)

Lampinen, James Michael; Meier, Christopher R.; Arnal, Jack D.; Leding, Juliana K.

2005-01-01

False memories are sometimes accompanied by surprisingly vivid experiential detail that makes them difficult to distinguish from actual memories. Such strikingly real false memories may be produced by a process called content borrowing in which details from presented items are errantly borrowed to corroborate the occurrence of the false memory…

Negative emotional content disrupts the coherence of episodic memories.

Science.gov (United States)

Bisby, James A; Horner, Aidan J; Bush, Daniel; Burgess, Neil

2018-02-01

Events are thought to be stored in episodic memory as coherent representations, in which the constituent elements are bound together so that a cue can trigger reexperience of all elements via pattern completion. Negative emotional content can strongly influence memory, but opposing theories predict strengthening or weakening of memory coherence. Across a series of experiments, participants imagined a number of person-location-object events with half of the events including a negative element (e.g., an injured person), and memory was tested across all within event associations. We show that the presence of a negative element reduces memory for associations between event elements, including between neutral elements encoded after a negative element. The presence of a negative element reduces the coherence with which a multimodal event is remembered. Our results, supported by a computational model, suggest that coherent retrieval from neutral events is supported by pattern completion, but that negative content weakens associative encoding which impairs this process. Our findings have important implications for understanding the way traumatic events are encoded and support therapeutic strategies aimed at restoring associations between negative content and its surrounding context. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Attention, working memory, and phenomenal experience of WM content: memory levels determined by different types of top-down modulation.

Science.gov (United States)

Jacob, Jane; Jacobs, Christianne; Silvanto, Juha

2015-01-01

What is the role of top-down attentional modulation in consciously accessing working memory (WM) content? In influential WM models, information can exist in different states, determined by allocation of attention; placing the original memory representation in the center of focused attention gives rise to conscious access. Here we discuss various lines of evidence indicating that such attentional modulation is not sufficient for memory content to be phenomenally experienced. We propose that, in addition to attentional modulation of the memory representation, another type of top-down modulation is required: suppression of all incoming visual information, via inhibition of early visual cortex. In this view, there are three distinct memory levels, as a function of the top-down control associated with them: (1) Nonattended, nonconscious associated with no attentional modulation; (2) attended, phenomenally nonconscious memory, associated with attentional enhancement of the actual memory trace; (3) attended, phenomenally conscious memory content, associated with enhancement of the memory trace and top-down suppression of all incoming visual input.

Emotional content enhances true but not false memory for categorized stimuli.

Science.gov (United States)

Choi, Hae-Yoon; Kensinger, Elizabeth A; Rajaram, Suparna

2013-04-01

Past research has shown that emotion enhances true memory, but that emotion can either increase or decrease false memory. Two theoretical possibilities-the distinctiveness of emotional stimuli and the conceptual relatedness of emotional content-have been implicated as being responsible for influencing both true and false memory for emotional content. In the present study, we sought to identify the mechanisms that underlie these mixed findings by equating the thematic relatedness of the study materials across each type of valence used (negative, positive, or neutral). In three experiments, categorically bound stimuli (e.g., funeral, pets, and office items) were used for this purpose. When the encoding task required the processing of thematic relatedness, a significant true-memory enhancement for emotional content emerged in recognition memory, but no emotional boost to false memory (exp. 1). This pattern persisted for true memory with a longer retention interval between study and test (24 h), and false recognition was reduced for emotional items (exp. 2). Finally, better recognition memory for emotional items once again emerged when the encoding task (arousal ratings) required the processing of the emotional aspect of the study items, with no emotional boost to false recognition (EXP. 3). Together, these findings suggest that when emotional and neutral stimuli are equivalently high in thematic relatedness, emotion continues to improve true memory, but it does not override other types of grouping to increase false memory.

Data fusion using dynamic associative memory

Science.gov (United States)

Lo, Titus K. Y.; Leung, Henry; Chan, Keith C. C.

1997-07-01

An associative memory, unlike an addressed memory used in conventional computers, is content addressable. That is, storing and retrieving information are not based on the location of the memory cell but on the content of the information. There are a number of approaches to implement an associative memory, one of which is to use a neural dynamical system where objects being memorized or recognized correspond to its basic attractors. The work presented in this paper is the investigation of applying a particular type of neural dynamical associative memory, namely the projection network, to pattern recognition and data fusion. Three types of attractors, which are fixed-point, limit- cycle, and chaotic, have been studied, evaluated and compared.

Autobiographical Memory Functioning among Abused, Neglected, and Nonmaltreated Children: The Overgeneral Memory Effect

Science.gov (United States)

Valentino, Kristin; Toth, Sheree L.; Cicchetti, Dante

2009-01-01

Background: This investigation addresses whether there are differences in the form and content of autobiographical memory recall as a function of maltreatment, and examines the roles of self-system functioning and psychopathology in autobiographical memory processes. Methods: Autobiographical memory for positive and negative nontraumatic events…

Negative Emotional Content Disrupts the Coherence of Episodic Memories

OpenAIRE

Bisby, James A.; Horner, Aidan J.; Bush, Daniel; Burgess, Neil

2017-01-01

Events are thought to be stored in episodic memory as coherent representations, in which the constituent elements are bound together so that a cue can trigger reexperience of all elements via pattern completion. Negative emotional content can strongly influence memory, but opposing theories predict strengthening or weakening of memory coherence. Across a series of experiments, participants imagined a number of person-location-object events with half of the events including a negative element ...

Effects of working memory contents and perceptual load on distractor processing: When a response-related distractor is held in working memory.

Science.gov (United States)

Koshino, Hideya

2017-01-01

Working memory and attention are closely related. Recent research has shown that working memory can be viewed as internally directed attention. Working memory can affect attention in at least two ways. One is the effect of working memory load on attention, and the other is the effect of working memory contents on attention. In the present study, an interaction between working memory contents and perceptual load in distractor processing was investigated. Participants performed a perceptual load task in a standard form in one condition (Single task). In the other condition, a response-related distractor was maintained in working memory, rather than presented in the same stimulus display as a target (Dual task). For the Dual task condition, a significant compatibility effect was found under high perceptual load; however, there was no compatibility effect under low perceptual load. These results suggest that the way the contents of working memory affect visual search depends on perceptual load. Copyright © 2016 Elsevier B.V. All rights reserved.

Attention, working memory, and phenomenal experience of WM content: memory levels determined by different types of top-down modulation

OpenAIRE

Jacob, Jane; Jacobs, Christianne; Silvanto, Juha

2015-01-01

What is the role of top-down attentional modulation in consciously accessing working memory (WM) content? In influential WM models, information can exist in different states, determined by allocation of attention; placing the original memory representation in the center of focused attention gives rise to conscious access. Here we discuss various lines of evidence indicating that such attentional modulation is not sufficient for memory content to be phenomenally experienced. We propose that, i...

Information Content Moderates Positivity and Negativity Biases in Memory

Science.gov (United States)

Hess, Thomas M.; Popham, Lauren E.; Dennis, Paul A.; Emery, Lisa

2014-01-01

Two experiments examined the impact of encoding conditions and information content in memory for positive, neutral, and negative pictures. We examined the hypotheses that the positivity effect in memory (i.e., a bias in favor of positive or against negative information in later life) would be reduced when (a) pictures were viewed under structured as opposed to unstructured conditions, and (b) contained social as opposed to nonsocial content. Both experiments found that the positivity effect observed with nonsocial stimuli was absent with social stimuli. In addition, little evidence was obtained that encoding conditions affected the strength of the positivity effect. We argue that some types of social stimuli may engage different types of processing than nonsocial stimuli, perhaps encouraging self-referential processing that engages attention and supports memory. This processing may then conflict with the goal-driven, top-down processing that is hypothesized to drive the positivity effect. Thus, our results identify further boundary conditions associated with the positivity effect in memory, arguing that stimulus factors as well as situational goals may affect its occurrence. Further research awaits to determine if this effect is specific to all social stimuli or specific subsets. PMID:23421322

Information content moderates positivity and negativity biases in memory.

Science.gov (United States)

Hess, Thomas M; Popham, Lauren E; Dennis, Paul A; Emery, Lisa

2013-09-01

Two experiments examined the impact of encoding conditions and information content in memory for positive, neutral, and negative pictures. We examined the hypotheses that the positivity effect in memory (i.e., a bias in favor of positive or against negative information in later life) would be reduced when (a) pictures were viewed under structured as opposed to unstructured conditions, and (b) contained social as opposed to nonsocial content. Both experiments found that the positivity effect observed with nonsocial stimuli was absent with social stimuli. In addition, little evidence was obtained that encoding conditions affected the strength of the positivity effect. We argue that some types of social stimuli may engage different types of processing than nonsocial stimuli, perhaps encouraging self-referential processing that engages attention and supports memory. This processing may then conflict with the goal-driven, top-down processing that is hypothesized to drive the positivity effect. Thus, our results identify further boundary conditions associated with the positivity effect in memory, arguing that stimulus factors as well as situational goals may affect its occurrence. Further research awaits to determine if this effect is specific to all social stimuli or specific subsets.

Feature-based memory-driven attentional capture: Visual working memory content affects visual attention.

NARCIS (Netherlands)

Olivers, C.N.L.; Meijer, F.; Theeuwes, J.

2006-01-01

In 7 experiments, the authors explored whether visual attention (the ability to select relevant visual information) and visual working memory (the ability to retain relevant visual information) share the same content representations. The presence of singleton distractors interfered more strongly

Effects of emotional content on working memory capacity.

Science.gov (United States)

Garrison, Katie E; Schmeichel, Brandon J

2018-02-13

Emotional events tend to be remembered better than neutral events, but emotional states and stimuli may also interfere with cognitive processes that underlie memory performance. The current study investigated the effects of emotional content on working memory capacity (WMC), which involves both short term storage and executive attention control. We tested competing hypotheses in a preregistered experiment (N = 297). The emotional enhancement hypothesis predicts that emotional stimuli attract attention and additional processing resources relative to neutral stimuli, thereby making it easier to encode and store emotional information in WMC. The emotional impairment hypothesis, by contrast, predicts that emotional stimuli interfere with attention control and the active maintenance of information in working memory. Participants completed a common measure of WMC (the operation span task; Turner, M. L., & Engle, R. W. [1989]. Is working memory capacity task dependent? Journal of Memory and Language, 28, 127-154) that included either emotional or neutral words. Results revealed that WMC was reduced for emotional words relative to neutral words, consistent with the emotional impairment hypothesis.

Trauma and autobiographical memory: contents and determinants of earliest memories among war-affected Palestinian children.

Science.gov (United States)

Peltonen, Kirsi; Kangaslampi, Samuli; Qouta, Samir; Punamäki, Raija-Leena

2017-11-01

The contents of earliest memories (EM), as part of autobiographical memory, continue to fascinate scientists and therapists. However, research is scarce on the determinants of EM, especially among children. This study aims, first, to identify contents of EM of children living in war conditions, and, second, to analyse child gender, traumatic events and mental health as determinants of the contents of EM. The participants were 240 Palestinian schoolchildren from the Gaza Strip (10-12 years, M = 11.35, SD = 0.57; 49.4% girls). They responded to an open-ended EM question, and reported their trauma exposures (war trauma, losses and current traumatic events), posttraumatic stress, depressive symptoms and psychosocial well-being, indicating mental health. The EM coding involved nature, social orientation, emotional tone and specificity. Results showed, first, that 43% reported playing or visiting a nice place as EM, and about a third (30%) traumatic events or accidents (30%) or miscellaneous events (27%). The individual and social orientation were almost equally common, the emotional tone mainly neutral (45.5%), and 60% remembered a specific event. Second, boys remembered more EM involving traumatic events or accidents, and girls more social events. Third, war trauma was associated with less positive emotional tone and with more specific memories.

Memory reactivation during rest supports upcoming learning of related content

Science.gov (United States)

Schlichting, Margaret L.; Preston, Alison R.

2014-01-01

Although a number of studies have highlighted the importance of offline processes for memory, how these mechanisms influence future learning remains unknown. Participants with established memories for a set of initial face–object associations were scanned during passive rest and during encoding of new related and unrelated pairs of objects. Spontaneous reactivation of established memories and enhanced hippocampal–neocortical functional connectivity during rest was related to better subsequent learning, specifically of related content. Moreover, the degree of functional coupling during rest was predictive of neural engagement during the new learning experience itself. These results suggest that through rest-phase reactivation and hippocampal–neocortical interactions, existing memories may come to facilitate encoding during subsequent related episodes. PMID:25331890

Memory reactivation during rest supports upcoming learning of related content.

Science.gov (United States)

Schlichting, Margaret L; Preston, Alison R

2014-11-04

Although a number of studies have highlighted the importance of offline processes for memory, how these mechanisms influence future learning remains unknown. Participants with established memories for a set of initial face-object associations were scanned during passive rest and during encoding of new related and unrelated pairs of objects. Spontaneous reactivation of established memories and enhanced hippocampal-neocortical functional connectivity during rest was related to better subsequent learning, specifically of related content. Moreover, the degree of functional coupling during rest was predictive of neural engagement during the new learning experience itself. These results suggest that through rest-phase reactivation and hippocampal-neocortical interactions, existing memories may come to facilitate encoding during subsequent related episodes.

Feature-Based Memory-Driven Attentional Capture: Visual Working Memory Content Affects Visual Attention

Science.gov (United States)

Olivers, Christian N. L.; Meijer, Frank; Theeuwes, Jan

2006-01-01

In 7 experiments, the authors explored whether visual attention (the ability to select relevant visual information) and visual working memory (the ability to retain relevant visual information) share the same content representations. The presence of singleton distractors interfered more strongly with a visual search task when it was accompanied by…

How visual working memory contents influence priming of visual attention.

Science.gov (United States)

Carlisle, Nancy B; Kristjánsson, Árni

2017-04-12

Recent evidence shows that when the contents of visual working memory overlap with targets and distractors in a pop-out search task, intertrial priming is inhibited (Kristjánsson, Sævarsson & Driver, Psychon Bull Rev 20(3):514-521, 2013, Experiment 2, Psychonomic Bulletin and Review). This may reflect an interesting interaction between implicit short-term memory-thought to underlie intertrial priming-and explicit visual working memory. Evidence from a non-pop-out search task suggests that it may specifically be holding distractors in visual working memory that disrupts intertrial priming (Cunningham & Egeth, Psychol Sci 27(4):476-485, 2016, Experiment 2, Psychological Science). We examined whether the inhibition of priming depends on whether feature values in visual working memory overlap with targets or distractors in the pop-out search, and we found that the inhibition of priming resulted from holding distractors in visual working memory. These results are consistent with separate mechanisms of target and distractor effects in intertrial priming, and support the notion that the impact of implicit short-term memory and explicit visual working memory can interact when each provides conflicting attentional signals.

When increasing distraction helps learning: Distractor number and content interact in their effects on memory.

Science.gov (United States)

Nussenbaum, Kate; Amso, Dima; Markant, Julie

2017-11-01

Previous work has demonstrated that increasing the number of distractors in a search array can reduce interference from distractor content during target processing. However, it is unclear how this reduced interference influences learning of target information. Here, we investigated how varying the amount and content of distraction present in a learning environment affects visual search and subsequent memory for target items. In two experiments, we demonstrate that the number and content of competing distractors interact in their influence on target selection and memory. Specifically, while increasing the number of distractors present in a search array made target detection more effortful, it did not impair learning and memory for target content. Instead, when the distractors contained category information that conflicted with the target, increasing the number of distractors from one to three actually benefitted learning and memory. These data suggest that increasing numbers of distractors may reduce interference from conflicting conceptual information during encoding.

Continuity of phenomenology and (in)consistency of content of meaningful autobiographical memories.

Science.gov (United States)

Luchetti, Martina; Rossi, Nicolino; Montebarocci, Ornella; Sutin, Angelina R

2016-05-01

Phenomenology is a critical component of autobiographical memory retrieval; it reflects both (a) memory-specific features and (b) stable individual differences. Few studies have tested phenomenology longitudinally. The present work examined the continuity of memory phenomenology in a sample of Italians adults (N=105) over a 4-week period. Participants retrieved two 'key' personal memories, a Turning Point and an Early Childhood Memory, rated the phenomenology of each memory, and completed measures of personality, psychological distress and subjective well-being. Phenomenological ratings were moderately stable over time (median correlation >.40), regardless of memory content. Personality traits, psychological distress and well-being were associated with phenomenology cross-sectionally and with changes in phenomenology over time. These results suggest that how individuals re-experience their most important personal memories is relatively consistent over time and shaped by both trait and state aspects of psychological functioning. Copyright © 2016 Elsevier Inc. All rights reserved.

CAN Tree Routing for Content-Addressable Network

Directory of Open Access Journals (Sweden)

Zhongtao LI

2014-01-01

Full Text Available We propose a novel topology to improve the routing performance of Content- Addressable Network overlays while minimizing the maintenance overhead during nodes churn. The key idea of our approach is to establish a P2P tree structure (CAN tree by means of equipping each node with a few long links towards some distant nodes. The long links enhance routing flexibility and robustness against failures. Nodes automatically adapt routing table to cope with network change. The routing complexity is O(log n, which is much better than a uniform greedy routing, while each node maintains two long links in average.

A light writable microfluidic "flash memory": optically addressed actuator array with latched operation for microfluidic applications.

Science.gov (United States)

Hua, Zhishan; Pal, Rohit; Srivannavit, Onnop; Burns, Mark A; Gulari, Erdogan

2008-03-01

This paper presents a novel optically addressed microactuator array (microfluidic "flash memory") with latched operation. Analogous to the address-data bus mediated memory address protocol in electronics, the microactuator array consists of individual phase-change based actuators addressed by localized heating through focused light patterns (address bus), which can be provided by a modified projector or high power laser pointer. A common pressure manifold (data bus) for the entire array is used to generate large deflections of the phase change actuators in the molten phase. The use of phase change material as the working media enables latched operation of the actuator array. After the initial light "writing" during which the phase is temporarily changed to molten, the actuated status is self-maintained by the solid phase of the actuator without power and pressure inputs. The microfluidic flash memory can be re-configured by a new light illumination pattern and common pressure signal. The proposed approach can achieve actuation of arbitrary units in a large-scale array without the need for complex external equipment such as solenoid valves and electrical modules, which leads to significantly simplified system implementation and compact system size. The proposed work therefore provides a flexible, energy-efficient, and low cost multiplexing solution for microfluidic applications based on physical displacements. As an example, the use of the latched microactuator array as "normally closed" or "normally open" microvalves is demonstrated. The phase-change wax is fully encapsulated and thus immune from contamination issues in fluidic environments.

Shape memory effect in Fe-Mn-Ni-Si-C alloys with low Mn contents

Energy Technology Data Exchange (ETDEWEB)

Min, X.H., E-mail: MIN.Xiaohua@nims.go.jp [National Institute for Materials Science, Tsukuba 305-0047 (Japan); Sawaguchi, T.; Ogawa, K. [National Institute for Materials Science, Tsukuba 305-0047 (Japan); Maruyama, T. [Awaji Materia Co., Ltd. 2-3-13, Kanda ogawamachi, Chiyoda, Tokyo 101-0052 (Japan); Yin, F.X. [National Institute for Materials Science, Tsukuba 305-0047 (Japan); Tsuzaki, K. [National Institute for Materials Science, Tsukuba 305-0047 (Japan); Graduate School of Pure and Applied Sciences, University of Tsukuba, Ibaraki 305-0047 (Japan)

2011-06-15

Highlights: {yields} A class of new Fe-Mn-Ni-Si-C shape memory alloys with low Mn contents has been designed. {yields} A Mn content for the onset of the {alpha}' martensite is less than 13 mass%, and the {epsilon} martensite still exists in the alloy with a 9 mass% Mn. {yields} The shape recovery strain decreases considerably when the Mn content is reduced from 13 to 11 mass%. {yields} The sudden decrease in the shape recovery strain is mainly caused by the formation of {alpha}' martensite. - Abstract: An attempt was made to develop a new Fe-Mn-Si-based shape memory alloy from a Fe-17Mn-6Si-0.3C (mass%) shape memory alloy, which was previously reported to show a superior shape memory effect without any costly training treatment, by lowering its Mn content. The shape memory effect and the phase transformation behavior were investigated for the as-solution treated Fe-(17-2x)Mn-6Si-0.3C-xNi (x = 0, 1, 2, 3, 4) polycrystalline alloys. The shape recovery strain exceeded 2% in the alloys with x = 0-2, which is sufficient for an industrially applicable shape memory effect; however, it suddenly decreased in the alloys between x = 2 and 3 although the significant shape recovery strain still exceeded 1%. In the alloys with x = 3 and 4, X-ray diffraction analysis and transmission electron microscope observation revealed the existence of {alpha}' martensite, which forms at the intersection of the {epsilon} martensite plates and suppresses the crystallographic reversibility of the {gamma} austenite to {epsilon} martensitic transformation.

Selective updating of working memory content modulates meso-cortico-striatal activity.

Science.gov (United States)

Murty, Vishnu P; Sambataro, Fabio; Radulescu, Eugenia; Altamura, Mario; Iudicello, Jennifer; Zoltick, Bradley; Weinberger, Daniel R; Goldberg, Terry E; Mattay, Venkata S

2011-08-01

Accumulating evidence from non-human primates and computational modeling suggests that dopaminergic signals arising from the midbrain (substantia nigra/ventral tegmental area) mediate striatal gating of the prefrontal cortex during the selective updating of working memory. Using event-related functional magnetic resonance imaging, we explored the neural mechanisms underlying the selective updating of information stored in working memory. Participants were scanned during a novel working memory task that parses the neurophysiology underlying working memory maintenance, overwriting, and selective updating. Analyses revealed a functionally coupled network consisting of a midbrain region encompassing the substantia nigra/ventral tegmental area, caudate, and dorsolateral prefrontal cortex that was selectively engaged during working memory updating compared to the overwriting and maintenance of working memory content. Further analysis revealed differential midbrain-dorsolateral prefrontal interactions during selective updating between low-performing and high-performing individuals. These findings highlight the role of this meso-cortico-striatal circuitry during the selective updating of working memory in humans, which complements previous research in behavioral neuroscience and computational modeling. Published by Elsevier Inc.

Architectures for a quantum random access memory

OpenAIRE

Giovannetti, Vittorio; Lloyd, Seth; Maccone, Lorenzo

2008-01-01

A random access memory, or RAM, is a device that, when interrogated, returns the content of a memory location in a memory array. A quantum RAM, or qRAM, allows one to access superpositions of memory sites, which may contain either quantum or classical information. RAMs and qRAMs with n-bit addresses can access 2^n memory sites. Any design for a RAM or qRAM then requires O(2^n) two-bit logic gates. At first sight this requirement might seem to make large scale quantum versions of such devices ...

Parietal and early visual cortices encode working memory content across mental transformations.

Science.gov (United States)

Christophel, Thomas B; Cichy, Radoslaw M; Hebart, Martin N; Haynes, John-Dylan

2015-02-01

Active and flexible manipulations of memory contents "in the mind's eye" are believed to occur in a dedicated neural workspace, frequently referred to as visual working memory. Such a neural workspace should have two important properties: The ability to store sensory information across delay periods and the ability to flexibly transform sensory information. Here we used a combination of functional MRI and multivariate decoding to indentify such neural representations. Subjects were required to memorize a complex artificial pattern for an extended delay, then rotate the mental image as instructed by a cue and memorize this transformed pattern. We found that patterns of brain activity already in early visual areas and posterior parietal cortex encode not only the initially remembered image, but also the transformed contents after mental rotation. Our results thus suggest that the flexible and general neural workspace supporting visual working memory can be realized within posterior brain regions. Copyright © 2014 Elsevier Inc. All rights reserved.

Do the Contents of Working Memory Capture Attention? Yes, but Cognitive Control Matters

Science.gov (United States)

Han, Suk Won; Kim, Min-Shik

2009-01-01

There has been a controversy on whether working memory can guide attentional selection. Some researchers have reported that the contents of working memory guide attention automatically in visual search (D. Soto, D. Heinke, G. W. Humphreys, & M. J. Blanco, 2005). On the other hand, G.F. Woodman and S. J. Luck (2007) reported that they could not…

Do the Contents of Visual Working Memory Automatically Influence Attentional Selection During Visual Search?

OpenAIRE

Woodman, Geoffrey F.; Luck, Steven J.

2007-01-01

In many theories of cognition, researchers propose that working memory and perception operate interactively. For example, in previous studies researchers have suggested that sensory inputs matching the contents of working memory will have an automatic advantage in the competition for processing resources. The authors tested this hypothesis by requiring observers to perform a visual search task while concurrently maintaining object representations in visual working memory. The hypothesis that ...

Memory architecture

NARCIS (Netherlands)

2012-01-01

A memory architecture is presented. The memory architecture comprises a first memory and a second memory. The first memory has at least a bank with a first width addressable by a single address. The second memory has a plurality of banks of a second width, said banks being addressable by components

The association of personal semantic memory to identity representations: insight into higher-order networks of autobiographical contents.

Science.gov (United States)

Grilli, Matthew D

2017-11-01

Identity representations are higher-order knowledge structures that organise autobiographical memories on the basis of personality and role-based themes of one's self-concept. In two experiments, the extent to which different types of personal semantic content are reflected in these higher-order networks of memories was investigated. Healthy, young adult participants generated identity representations that varied in remoteness of formation and verbally reflected on these themes in an open-ended narrative task. The narrative responses were scored for retrieval of episodic, experience-near personal semantic and experience-far (i.e., abstract) personal semantic contents. Results revealed that to reflect on remotely formed identity representations, experience-far personal semantic contents were retrieved more than experience-near personal semantic contents. In contrast, to reflect on recently formed identity representations, experience-near personal semantic contents were retrieved more than experience-far personal semantic contents. Although episodic memory contents were retrieved less than both personal semantic content types to reflect on remotely formed identity representations, this content type was retrieved at a similar frequency as experience-far personal semantic content to reflect on recently formed identity representations. These findings indicate that the association of personal semantic content to identity representations is robust and related to time since acquisition of these knowledge structures.

Do the Contents of Visual Working Memory Automatically Influence Attentional Selection during Visual Search?

Science.gov (United States)

Woodman, Geoffrey F.; Luck, Steven J.

2007-01-01

In many theories of cognition, researchers propose that working memory and perception operate interactively. For example, in previous studies researchers have suggested that sensory inputs matching the contents of working memory will have an automatic advantage in the competition for processing resources. The authors tested this hypothesis by…

An Analysis of an Ultra-High Speed Content-Addressable Database Retrieval System

National Research Council Canada - National Science Library

Costianes, Peter

2001-01-01

This work presents a model for assessing the performance of a paradigm and its implementation first proposed by Chou, Detofsky, and Louri entitled Multiwavelength Optical Content-Addressable Parallel Processor (MW-OCAPP...

Unraveling Network-induced Memory Contention: Deeper Insights with Machine Learning

International Nuclear Information System (INIS)

Groves, Taylor Liles; Grant, Ryan; Gonzales, Aaron; Arnold, Dorian

2017-01-01

Remote Direct Memory Access (RDMA) is expected to be an integral communication mechanism for future exascale systems enabling asynchronous data transfers, so that applications may fully utilize CPU resources while simultaneously sharing data amongst remote nodes. We examine Network-induced Memory Contention (NiMC) on Infiniband networks. We expose the interactions between RDMA, main-memory and cache, when applications and out-of-band services compete for memory resources. We then explore NiMCs resulting impact on application-level performance. For a range of hardware technologies and HPC workloads, we quantify NiMC and show that NiMCs impact grows with scale resulting in up to 3X performance degradation at scales as small as 8K processes even in applications that previously have been shown to be performance resilient in the presence of noise. In addition, this work examines the problem of predicting NiMC's impact on applications by leveraging machine learning and easily accessible performance counters. This approach provides additional insights about the root cause of NiMC and facilitates dynamic selection of potential solutions. Finally, we evaluated three potential techniques to reduce NiMCs impact, namely hardware offloading, core reservation and network throttling.

Testing Memories of Personally Experienced Events: The Testing Effect Seems Not to Persist in Autobiographical Memory

Science.gov (United States)

Emmerdinger, Kathrin J.; Kuhbandner, Christof

2018-01-01

Numerous studies have shown that retrieving contents from memory in a test improves long-term retention for those contents, even when compared to restudying (i.e., the “testing effect”). The beneficial effect of retrieval practice has been demonstrated for many different types of memory representations; however, one particularly important memory system has not been addressed in previous testing effect research: autobiographical memory. The aim of the present study was to examine the effect of retrieving memories for personally experienced events on long-term memory for those events. In an initial elicitation session, participants described memories for personally experienced events in response to a variety of cue words. In a retrieval practice/restudy session the following day, they repeatedly practiced retrieval for half of their memories by recalling and writing down the previously described events; the other half of memories was restudied by rereading and copying the event descriptions. Long-term retention of all previously collected memories was assessed at two different retention intervals (2 weeks and 13 weeks). In the retrieval practice session, a hypermnesic effect emerged, with memory performance increasing across the practice cycles. Long-term memory performance significantly dropped from the 2-weeks to the 13-weeks retention interval, but no significant difference in memory performance was observed between previously repeatedly retrieved and previously repeatedly restudied memories. Thus, in autobiographical memory, retrieval practice seems to be no more beneficial for long-term retention than repeated re-exposure. PMID:29881365

A Josephson ternary associative memory cell

International Nuclear Information System (INIS)

Morisue, M.; Suzuki, K.

1989-01-01

This paper describes a three-valued content addressable memory cell using a Josephson complementary ternary logic circuit named as JCTL. The memory cell proposed here can perform three operations of searching, writing and reading in ternary logic system. The principle of the memory circuit is illustrated in detail by using the threshold-characteristics of the JCTL. In order to investigate how a high performance operation can be achieved, computer simulations have been made. Simulation results show that the cycle time of memory operation is 120psec, power consumption is about 0.5 μW/cell and tolerances of writing and reading operation are +-15% and +-24%, respectively

Trinary Associative Memory Would Recognize Machine Parts

Science.gov (United States)

Liu, Hua-Kuang; Awwal, Abdul Ahad S.; Karim, Mohammad A.

1991-01-01

Trinary associative memory combines merits and overcomes major deficiencies of unipolar and bipolar logics by combining them in three-valued logic that reverts to unipolar or bipolar binary selectively, as needed to perform specific tasks. Advantage of associative memory: one obtains access to all parts of it simultaneously on basis of content, rather than address, of data. Consequently, used to exploit fully parallelism and speed of optical computing.

SIR JOHN CRAWFORD MEMORIAL ADDRESS: Agriculture: The challenges of the 21st century

OpenAIRE

Beddington, Sir John

2012-01-01

The Sir John Crawford Memorial Address has been presented since 1985, in honour of the distinguished Australian civil servant, educator and agriculturalist in whose name the Crawford Fund was established. Sir John Crawford was a remarkable Australian who contributed at the highest levels, and was a passionate supporter of international agricultural research for development. This talk draws attention to four current and interrelated trends that suggest the world will be rather different by 202...

Multi-Core Processor Memory Contention Benchmark Analysis Case Study

Science.gov (United States)

Simon, Tyler; McGalliard, James

2009-01-01

Multi-core processors dominate current mainframe, server, and high performance computing (HPC) systems. This paper provides synthetic kernel and natural benchmark results from an HPC system at the NASA Goddard Space Flight Center that illustrate the performance impacts of multi-core (dual- and quad-core) vs. single core processor systems. Analysis of processor design, application source code, and synthetic and natural test results all indicate that multi-core processors can suffer from significant memory subsystem contention compared to similar single-core processors.

Resonator memories and optical novelty filters

Science.gov (United States)

Anderson, Dana Z.; Erle, Marie C.

Optical resonators having holographic elements are potential candidates for storing information that can be accessed through content addressable or associative recall. Closely related to the resonator memory is the optical novelty filter, which can detect the differences between a test object and a set of reference objects. We discuss implementations of these devices using continuous optical media such as photorefractive materials. The discussion is framed in the context of neural network models. There are both formal and qualitative similarities between the resonator memory and optical novelty filter and network models. Mode competition arises in the theory of the resonator memory, much as it does in some network models. We show that the role of the phenomena of "daydreaming" in the real-time programmable optical resonator is very much akin to the role of "unlearning" in neural network memories. The theory of programming the real-time memory for a single mode is given in detail. This leads to a discussion of the optical novelty filter. Experimental results for the resonator memory, the real-time programmable memory, and the optical tracking novelty filter are reviewed. We also point to several issues that need to be addressed in order to implement more formal models of neural networks.

Large scale integration of flexible non-volatile, re-addressable memories using P(VDF-TrFE) and amorphous oxide transistors

International Nuclear Information System (INIS)

Gelinck, Gerwin H; Cobb, Brian; Van Breemen, Albert J J M; Myny, Kris

2015-01-01

Ferroelectric polymers and amorphous metal oxide semiconductors have emerged as important materials for re-programmable non-volatile memories and high-performance, flexible thin-film transistors, respectively. However, realizing sophisticated transistor memory arrays has proven to be a challenge, and demonstrating reliable writing to and reading from such a large scale memory has thus far not been demonstrated. Here, we report an integration of ferroelectric, P(VDF-TrFE), transistor memory arrays with thin-film circuitry that can address each individual memory element in that array. n-type indium gallium zinc oxide is used as the active channel material in both the memory and logic thin-film transistors. The maximum process temperature is 200 °C, allowing plastic films to be used as substrate material. The technology was scaled up to 150 mm wafer size, and offers good reproducibility, high device yield and low device variation. This forms the basis for successful demonstration of memory arrays, read and write circuitry, and the integration of these. (paper)

Memory for media: investigation of false memories for negatively and positively charged public events.

Science.gov (United States)

Porter, Stephen; Taylor, Kristian; Ten Brinke, Leanne

2008-01-01

Despite a large body of false memory research, little has addressed the potential influence of an event's emotional content on susceptibility to false recollections. The Paradoxical Negative Emotion (PNE) hypothesis predicts that negative emotion generally facilitates memory but also heightens susceptibility to false memories. Participants were asked whether they could recall 20 "widely publicised" public events (half fictitious) ranging in emotional valence, with or without visual cues. Participants recalled a greater number of true negative events (M=3.31/5) than true positive (M=2.61/5) events. Nearly everyone (95%) came to recall at least one false event (M=2.15 false events recalled). Further, more than twice as many participants recalled any false negative (90%) compared to false positive (41.7%) events. Negative events, in general, were associated with more detailed memories and false negative event memories were more detailed than false positive event memories. Higher dissociation scores were associated with false recollections of negative events, specifically.

Enhancement of declarative memory associated with emotional content in a Brazilian sample

Directory of Open Access Journals (Sweden)

Frank J.E.

2000-01-01

Full Text Available Several studies have documented that emotional arousal may enhance long-term memory. This is an adaptation of a paradigm previously used in North American and European samples in investigations of the influence of emotion on long-term retention. A sample of 46 healthy adults of high and low educational levels watched a slide presentation of stories. A randomly assigned group watched a story with an arousing content and another group watched a neutral story. The stories were matched for structure and comprehensibility and the set and order of the 11 slides were the same in both conditions. Immediately after viewing the slide presentation, the participants were asked to rate the emotionality of the narrative. The arousing narrative was rated as being more emotional than the neutral narrative (t (44 = -3.6, P<0.001. Ten days later subjects were asked to remember the story and answer a multiple-choice questionnaire about it. The subjects who watched the arousing story had higher scores in the free recall measure (t (44 = -2.59, P<0.01. There were no differences between groups in the multiple-choice test of recognition memory (t (44 = 0.26. These findings confirm that an emotional arousing content enhances long-term declarative memory and indicate the possibility of applying this instrument to clinical samples of various cultural backgrounds.

Information matching the content of visual working memory is prioritized for conscious access.

Science.gov (United States)

Gayet, Surya; Paffen, Chris L E; Van der Stigchel, Stefan

2013-12-01

Visual working memory (VWM) is used to retain relevant information for imminent goal-directed behavior. In the experiments reported here, we found that VWM helps to prioritize relevant information that is not yet available for conscious experience. In five experiments, we demonstrated that information matching VWM content reaches visual awareness faster than does information not matching VWM content. Our findings suggest a functional link between VWM and visual awareness: The content of VWM is recruited to funnel down the vast amount of sensory input to that which is relevant for subsequent behavior and therefore requires conscious access.

Effects of Working Memory Capacity and Content Familiarity on Literal and Inferential Comprehension in L2 Reading

Science.gov (United States)

Alptekin, Cem; Ercetin, Gulcan

2011-01-01

This study examines the effects of working memory capacity and content familiarity on literal and inferential comprehension in second language (L2) reading. Participants were 62 Turkish university students with an advanced English proficiency level. Working memory capacity was measured through a computerized version of a reading span test, whereas…

Decoding the content of visual short-term memory under distraction in occipital and parietal areas.

Science.gov (United States)

Bettencourt, Katherine C; Xu, Yaoda

2016-01-01

Recent studies have provided conflicting accounts regarding where in the human brain visual short-term memory (VSTM) content is stored, with strong univariate fMRI responses being reported in superior intraparietal sulcus (IPS), but robust multivariate decoding being reported in occipital cortex. Given the continuous influx of information in everyday vision, VSTM storage under distraction is often required. We found that neither distractor presence nor predictability during the memory delay affected behavioral performance. Similarly, superior IPS exhibited consistent decoding of VSTM content across all distractor manipulations and had multivariate responses that closely tracked behavioral VSTM performance. However, occipital decoding of VSTM content was substantially modulated by distractor presence and predictability. Furthermore, we found no effect of target-distractor similarity on VSTM behavioral performance, further challenging the role of sensory regions in VSTM storage. Overall, consistent with previous univariate findings, our results indicate that superior IPS, but not occipital cortex, has a central role in VSTM storage.

Decoding the content of visual short-term memory under distraction in occipital and parietal areas

Science.gov (United States)

Bettencourt, Katherine C.; Xu, Yaoda

2015-01-01

Recent studies have provided conflicting accounts regarding where in the human brain visual short-term memory (VSTM) content is stored, with strong univariate fMRI responses reported in superior intraparietal sulcus (IPS) but robust multivariate decoding reported in occipital cortex. Given the continuous influx of information in everyday vision, VSTM storage under distraction is often required. We found that neither distractor presence nor predictability during the memory delay affected behavioral performance. Similarly, superior IPS exhibited consistent decoding of VSTM content across all distractor manipulations and had multivariate responses that closely tracked behavioral VSTM performance. However, occipital decoding of VSTM content was significantly modulated by distractor presence and predictability. Furthermore, we found no effect of target-distractor similarity on VSTM behavioral performance, further challenging the role of sensory regions in VSTM storage. Overall, consistent with previous univariate findings, these results show that superior IPS, not occipital cortex, plays a central role in VSTM storage. PMID:26595654

Episodic and semantic content of memory and imagination: A multilevel analysis.

Science.gov (United States)

Devitt, Aleea L; Addis, Donna Rose; Schacter, Daniel L

2017-10-01

Autobiographical memories of past events and imaginations of future scenarios comprise both episodic and semantic content. Correlating the amount of "internal" (episodic) and "external" (semantic) details generated when describing autobiographical events can illuminate the relationship between the processes supporting these constructs. Yet previous studies performing such correlations were limited by aggregating data across all events generated by an individual, potentially obscuring the underlying relationship within the events themselves. In the current article, we reanalyzed datasets from eight studies using a multilevel approach, allowing us to explore the relationship between internal and external details within events. We also examined whether this relationship changes with healthy aging. Our reanalyses demonstrated a largely negative relationship between the internal and external details produced when describing autobiographical memories and future imaginations. This negative relationship was stronger and more consistent for older adults and was evident both in direct and indirect measures of semantic content. Moreover, this relationship appears to be specific to episodic tasks, as no relationship was observed for a nonepisodic picture description task. This negative association suggests that people do not generate semantic information indiscriminately, but do so in a compensatory manner, to embellish episodically impoverished events. Our reanalysis further lends support for dissociable processes underpinning episodic and semantic information generation when remembering and imagining autobiographical events.

Characteristics of the memory sources of dreams: A new version of the content-matching paradigm to take mundane and remote memories into account.

Directory of Open Access Journals (Sweden)

Raphael Vallat

Full Text Available Several studies have demonstrated that dream content is related to the waking life of the dreamer. However, the characteristics of the memory sources incorporated into dreams are still unclear. We designed a new protocol to investigate remote memories and memories of trivial experiences, both relatively unexplored in dream content until now. Upon awakening, for 7 days, participants identified the waking life elements (WLEs related to their dream content and characterized them and their dream content on several scales to assess notably emotional valence. Thanks to this procedure, they could report WLEs from the whole lifespan, and mundane ones before they had been forgotten. Participants (N = 40, 14 males, age = 25.2 ± 7.6 reported 6.2 ± 2.0 dreams on average. For each participant, 83.4% ± 17.8 of the dream reports were related to one or more WLEs. Among all the WLEs incorporated into dreams dated by the participants (79.3 ± 19%, 40.2 ± 30% happened the day before the dream, 26.1 ± 26% the month before (the day before excluded, 15.8 ± 21% the year before the dream (the month before excluded, and 17.9 ± 24% happened more than one year before the dream. As could be expected from previous studies, the majority of the WLEs incorporated into dreams were scored as important by the dreamers. However, this was not true for incorporated WLEs dating from the day before the dream. In agreement with Freud's observations, the majority of the day residues were scored as mundane. Finally, for both positive and negative WLEs incorporated into dreams, the dreamt version of the WLE was rated as emotionally less intense than the original WLE. This result, showing that dreams tend to attenuate the emotional tone of waking-life memories towards a more neutral one, argues in favor of the emotional regulation hypothesis of dreaming.

Characteristics of the memory sources of dreams: A new version of the content-matching paradigm to take mundane and remote memories into account.

Science.gov (United States)

Vallat, Raphael; Chatard, Benoit; Blagrove, Mark; Ruby, Perrine

2017-01-01

Several studies have demonstrated that dream content is related to the waking life of the dreamer. However, the characteristics of the memory sources incorporated into dreams are still unclear. We designed a new protocol to investigate remote memories and memories of trivial experiences, both relatively unexplored in dream content until now. Upon awakening, for 7 days, participants identified the waking life elements (WLEs) related to their dream content and characterized them and their dream content on several scales to assess notably emotional valence. Thanks to this procedure, they could report WLEs from the whole lifespan, and mundane ones before they had been forgotten. Participants (N = 40, 14 males, age = 25.2 ± 7.6) reported 6.2 ± 2.0 dreams on average. For each participant, 83.4% ± 17.8 of the dream reports were related to one or more WLEs. Among all the WLEs incorporated into dreams dated by the participants (79.3 ± 19%), 40.2 ± 30% happened the day before the dream, 26.1 ± 26% the month before (the day before excluded), 15.8 ± 21% the year before the dream (the month before excluded), and 17.9 ± 24% happened more than one year before the dream. As could be expected from previous studies, the majority of the WLEs incorporated into dreams were scored as important by the dreamers. However, this was not true for incorporated WLEs dating from the day before the dream. In agreement with Freud's observations, the majority of the day residues were scored as mundane. Finally, for both positive and negative WLEs incorporated into dreams, the dreamt version of the WLE was rated as emotionally less intense than the original WLE. This result, showing that dreams tend to attenuate the emotional tone of waking-life memories towards a more neutral one, argues in favor of the emotional regulation hypothesis of dreaming.

Addressing Phonological Memory in Language Therapy with Clients Who Have Down Syndrome: Perspectives of Speech-Language Pathologists

Science.gov (United States)

Faught, Gayle G.; Conners, Frances A.; Barber, Angela B.; Price, Hannah R.

2016-01-01

Background: Phonological memory (PM) plays a significant role in language development but is impaired in individuals with Down syndrome (DS). Without formal recommendations on how to address PM limitations in clients with DS, it is possible speech-language pathologists (SLPs) find ways to do so in their practices. Aims: This study asked if and how…

A New Conceptualization of Human Visual Sensory-Memory.

Science.gov (United States)

Öğmen, Haluk; Herzog, Michael H

2016-01-01

Memory is an essential component of cognition and disorders of memory have significant individual and societal costs. The Atkinson-Shiffrin "modal model" forms the foundation of our understanding of human memory. It consists of three stores: Sensory Memory (SM), whose visual component is called iconic memory, Short-Term Memory (STM; also called working memory, WM), and Long-Term Memory (LTM). Since its inception, shortcomings of all three components of the modal model have been identified. While the theories of STM and LTM underwent significant modifications to address these shortcomings, models of the iconic memory remained largely unchanged: A high capacity but rapidly decaying store whose contents are encoded in retinotopic coordinates, i.e., according to how the stimulus is projected on the retina. The fundamental shortcoming of iconic memory models is that, because contents are encoded in retinotopic coordinates, the iconic memory cannot hold any useful information under normal viewing conditions when objects or the subject are in motion. Hence, half-century after its formulation, it remains an unresolved problem whether and how the first stage of the modal model serves any useful function and how subsequent stages of the modal model receive inputs from the environment. Here, we propose a new conceptualization of human visual sensory memory by introducing an additional component whose reference-frame consists of motion-grouping based coordinates rather than retinotopic coordinates. We review data supporting this new model and discuss how it offers solutions to the paradoxes of the traditional model of sensory memory.

A New Conceptualization of Human Visual Sensory-Memory

Science.gov (United States)

Öğmen, Haluk; Herzog, Michael H.

2016-01-01

Memory is an essential component of cognition and disorders of memory have significant individual and societal costs. The Atkinson–Shiffrin “modal model” forms the foundation of our understanding of human memory. It consists of three stores: Sensory Memory (SM), whose visual component is called iconic memory, Short-Term Memory (STM; also called working memory, WM), and Long-Term Memory (LTM). Since its inception, shortcomings of all three components of the modal model have been identified. While the theories of STM and LTM underwent significant modifications to address these shortcomings, models of the iconic memory remained largely unchanged: A high capacity but rapidly decaying store whose contents are encoded in retinotopic coordinates, i.e., according to how the stimulus is projected on the retina. The fundamental shortcoming of iconic memory models is that, because contents are encoded in retinotopic coordinates, the iconic memory cannot hold any useful information under normal viewing conditions when objects or the subject are in motion. Hence, half-century after its formulation, it remains an unresolved problem whether and how the first stage of the modal model serves any useful function and how subsequent stages of the modal model receive inputs from the environment. Here, we propose a new conceptualization of human visual sensory memory by introducing an additional component whose reference-frame consists of motion-grouping based coordinates rather than retinotopic coordinates. We review data supporting this new model and discuss how it offers solutions to the paradoxes of the traditional model of sensory memory. PMID:27375519

Effects of 5-HT and insulin on learning and memory formation in food-deprived snails.

Science.gov (United States)

Aonuma, Hitoshi; Totani, Yuki; Kaneda, Mugiho; Nakamura, Ryota; Watanabe, Takayuki; Hatakeyama, Dai; Dyakonova, Varvara E; Lukowiak, Ken; Ito, Etsuro

2018-02-01

The pond snail Lymnaea stagnalis learns conditioned taste aversion (CTA) and consolidates it into long-term memory (LTM). How well they learn and form memory depends on the degree of food deprivation. Serotonin (5-HT) plays an important role in mediating feeding, and insulin enhances the memory consolidation process following CTA training. However, the relationship between these two signaling pathways has not been addressed. We measured the 5-HT content in the central nervous system (CNS) of snails subjected to different durations of food deprivation. One-day food-deprived snails, which exhibit the best learning and memory, had the lowest 5-HT content in the CNS, whereas 5-day food-deprived snails, which do not learn, had a high 5-HT content. Immersing 1-day food-deprived snails in 5-HT impaired learning and memory by causing an increase in 5-HT content, and that the injection of insulin into these snails reversed this impairment. We conclude that insulin rescues the CTA deficit and this may be due to a decrease in the 5-HT content in the CNS of Lymnaea. Copyright © 2018 Elsevier Inc. All rights reserved.

Direct Access to Working Memory Contents

NARCIS (Netherlands)

Bialkova, S.E.; Oberauer, K.

2010-01-01

Abstract. In two experiments participants held in working memory (WM) three digits in three different colors, and updated individual digits with the results of arithmetic equations presented in one of the colors. In the memory-access condition, a digit from WM had to be used as the first number in

37 CFR 301.2 - Official addresses.

Science.gov (United States)

2010-07-01

..., Room LM-401 in the James Madison Memorial Building, Monday through Friday, between 8:30 a.m. and 5 p.m., and be addressed as follows: Copyright Royalty Board, Library of Congress, James Madison Memorial... Royalty Board, Library of Congress, James Madison Memorial Building, 101 Independence Avenue, SE...

A Novel CAN Tree Coordinate Routing in Content-Addressable Network

Directory of Open Access Journals (Sweden)

Zhongtao Li

2014-09-01

Full Text Available In this paper, we propose a novel approach to improve coordination routing while minimizing the maintenance overhead during nodes churn. It bases on “CAN Tree Routing for Content- Addressable Network” 1 which is a solution for peer-to-peer routing. We concentrated on coordinate routing in this paper. The key idea of our approach is a recursion process to calculate target zone code and search in CAN tree 1. Because the hops are via long links in CAN, it enhances routing flexibility and robustness against failures. Nodes automatically adapt routing table to cope with network change. The routing complexity is , which is much better than a uniform greedy routing, while each node maintains two long links in average.

Effects of Violent and Non-Violent Computer Game Content on Memory Performance in Adolescents

Science.gov (United States)

Maass, Asja; Kollhorster, Kirsten; Riediger, Annemarie; MacDonald, Vanessa; Lohaus, Arnold

2011-01-01

The present study focuses on the short-term effects of electronic entertainment media on memory and learning processes. It compares the effects of violent versus non-violent computer game content in a condition of playing and in another condition of watching the same game. The participants consisted of 83 female and 94 male adolescents with a mean…

Oscillations and Episodic Memory: Addressing the Synchronization/Desynchronization Conundrum

OpenAIRE

Hanslmayr, Simon; Staresina, Bernhard P.; Bowman, Howard

2016-01-01

Trends Data from rodent as well as human studies suggest that theta/gamma synchronization in the hippocampus (i.e., theta phase to gamma power cross-frequency coupling) mediates the binding of different elements in episodic memory. In vivo and in vitro animal studies suggest that theta provides selective time windows for fast-acting synaptic modifications and recent computational models have implemented these mechanisms to explain human memory formation and retrieval. Recent data from human e...

`Unlearning' has a stabilizing effect in collective memories

Science.gov (United States)

Hopfield, J. J.; Feinstein, D. I.; Palmer, R. G.

1983-07-01

Crick and Mitchison1 have presented a hypothesis for the functional role of dream sleep involving an `unlearning' process. We have independently carried out mathematical and computer modelling of learning and `unlearning' in a collective neural network of 30-1,000 neurones. The model network has a content-addressable memory or `associative memory' which allows it to learn and store many memories. A particular memory can be evoked in its entirety when the network is stimulated by any adequate-sized subpart of the information of that memory2. But different memories of the same size are not equally easy to recall. Also, when memories are learned, spurious memories are also created and can also be evoked. Applying an `unlearning' process, similar to the learning processes but with a reversed sign and starting from a noise input, enhances the performance of the network in accessing real memories and in minimizing spurious ones. Although our model was not motivated by higher nervous function, our system displays behaviours which are strikingly parallel to those needed for the hypothesized role of `unlearning' in rapid eye movement (REM) sleep.

Centrally managed unified shared virtual address space

Science.gov (United States)

Wilkes, John

2018-02-13

Systems, apparatuses, and methods for managing a unified shared virtual address space. A host may execute system software and manage a plurality of nodes coupled to the host. The host may send work tasks to the nodes, and for each node, the host may externally manage the node's view of the system's virtual address space. Each node may have a central processing unit (CPU) style memory management unit (MMU) with an internal translation lookaside buffer (TLB). In one embodiment, the host may be coupled to a given node via an input/output memory management unit (IOMMU) interface, where the IOMMU frontend interface shares the TLB with the given node's MMU. In another embodiment, the host may control the given node's view of virtual address space via memory-mapped control registers.

Evidence of estrogen modulation on memory processes for emotional content in healthy young women.

Science.gov (United States)

Pompili, Assunta; Arnone, Benedetto; D'Amico, Mario; Federico, Paolo; Gasbarri, Antonella

2016-03-01

It is well accepted that emotional content can affect memory, interacting with the encoding and consolidation processes. The aim of the present study was to verify the effects of estrogens in the interplay of cognition and emotion. Images from the International Affective Pictures System, based on valence (pleasant, unpleasant and neutral), maintaining arousal constant, were viewed passively by two groups of young women in different cycle phases: a periovulatory group (PO), characterized by high level of estrogens and low level of progesterone, and an early follicular group (EF), characterized by low levels of both estrogens and progesterone. The electrophysiological responses to images were measured, and P300 peak was considered. One week later, long-term memory was tested by means of free recall. Intra-group analysis displayed that PO woman had significantly better memory for positive images, while EF women showed significantly better memory for negative images. The comparison between groups revealed that women in the PO phase had better memory performance for positive pictures than women in the EF phase, while no significant differences were found for negative and neutral pictures. According to the free recall results, the subjects in the PO group showed greater P300 amplitude, and shorter latency, for pleasant images compared with women in the EF group. Our results showed that the physiological hormonal fluctuation of estrogens during the menstrual cycle can influence memory, at the time of encoding, during the processing of emotional information. Copyright © 2015 Elsevier Ltd. All rights reserved.

Quantum random access memory

OpenAIRE

Giovannetti, Vittorio; Lloyd, Seth; Maccone, Lorenzo

2007-01-01

A random access memory (RAM) uses n bits to randomly address N=2^n distinct memory cells. A quantum random access memory (qRAM) uses n qubits to address any quantum superposition of N memory cells. We present an architecture that exponentially reduces the requirements for a memory call: O(log N) switches need be thrown instead of the N used in conventional (classical or quantum) RAM designs. This yields a more robust qRAM algorithm, as it in general requires entanglement among exponentially l...

A System for True and False Memory Prediction Based on 2D and 3D Educational Contents and EEG Brain Signals.

Science.gov (United States)

Bamatraf, Saeed; Hussain, Muhammad; Aboalsamh, Hatim; Qazi, Emad-Ul-Haq; Malik, Amir Saeed; Amin, Hafeez Ullah; Mathkour, Hassan; Muhammad, Ghulam; Imran, Hafiz Muhammad

2016-01-01

We studied the impact of 2D and 3D educational contents on learning and memory recall using electroencephalography (EEG) brain signals. For this purpose, we adopted a classification approach that predicts true and false memories in case of both short term memory (STM) and long term memory (LTM) and helps to decide whether there is a difference between the impact of 2D and 3D educational contents. In this approach, EEG brain signals are converted into topomaps and then discriminative features are extracted from them and finally support vector machine (SVM) which is employed to predict brain states. For data collection, half of sixty-eight healthy individuals watched the learning material in 2D format whereas the rest watched the same material in 3D format. After learning task, memory recall tasks were performed after 30 minutes (STM) and two months (LTM), and EEG signals were recorded. In case of STM, 97.5% prediction accuracy was achieved for 3D and 96.6% for 2D and, in case of LTM, it was 100% for both 2D and 3D. The statistical analysis of the results suggested that for learning and memory recall both 2D and 3D materials do not have much difference in case of STM and LTM.

Do Sex and Violence Sell? A Meta-Analytic Review of the Effects of Sexual and Violent Media and Ad Content on Memory, Attitudes, and Buying Intentions.

Science.gov (United States)

Lull, Robert B; Bushman, Brad J

2015-09-01

It is commonly assumed that sex and violence sell. However, we predicted that sex and violence would have the opposite effect. We based our predictions on the evolution and emotional arousal theoretical framework, which states that people are evolutionarily predisposed to attend to emotionally arousing cues such as sex and violence. Thus, sexual and violent cues demand more cognitive resources than nonsexual and nonviolent cues. Using this framework, we meta-analyzed the effects of sexual media, violent media, sexual ads, and violent ads on the advertising outcomes of brand memory, brand attitudes, and buying intentions. The meta-analysis included 53 experiments involving 8,489 participants. Analyses found that brands advertised in violent media content were remembered less often, evaluated less favorably, and less likely to be purchased than brands advertised in nonviolent, nonsexual media. Brands advertised using sexual ads were evaluated less favorably than brands advertised using nonviolent, nonsexual ads. There were no significant effects of sexual media on memory or buying intentions. There were no significant effects of sexual or violent ads on memory or buying intentions. As intensity of sexual ad content increased, memory, attitudes, and buying intentions decreased. When media content and ad content were congruent (e.g., violent ad in a violent program), memory improved and buying intentions increased. Violence and sex never helped and often hurt ad effectiveness. These results support the evolution and emotional arousal framework. Thus, advertisers should consider the effects of media content, ad content, content intensity, and congruity to design and place more effective ads. (c) 2015 APA, all rights reserved).

Centrally managed unified shared virtual address space

Energy Technology Data Exchange (ETDEWEB)

Wilkes, John

2018-02-13

Systems, apparatuses, and methods for managing a unified shared virtual address space. A host may execute system software and manage a plurality of nodes coupled to the host. The host may send work tasks to the nodes, and for each node, the host may externally manage the node's view of the system's virtual address space. Each node may have a central processing unit (CPU) style memory management unit (MMU) with an internal translation lookaside buffer (TLB). In one embodiment, the host may be coupled to a given node via an input/output memory management unit (IOMMU) interface, where the IOMMU frontend interface shares the TLB with the given node's MMU. In another embodiment, the host may control the given node's view of virtual address space via memory-mapped control registers.

Configurable memory system and method for providing atomic counting operations in a memory device

Science.gov (United States)

Bellofatto, Ralph E.; Gara, Alan G.; Giampapa, Mark E.; Ohmacht, Martin

2010-09-14

A memory system and method for providing atomic memory-based counter operations to operating systems and applications that make most efficient use of counter-backing memory and virtual and physical address space, while simplifying operating system memory management, and enabling the counter-backing memory to be used for purposes other than counter-backing storage when desired. The encoding and address decoding enabled by the invention provides all this functionality through a combination of software and hardware.

Resource-sharing between internal maintenance and external selection modulates attentional capture by working memory content

Directory of Open Access Journals (Sweden)

Anastasia eKiyonaga

2014-08-01

Full Text Available It is unclear why and under what circumstances working memory (WM and attention interact. Here, we apply the logic of the time-based resource-sharing (TBRS model of WM (e.g., Barrouillet, Bernardin, & Camos, 2004 to explore the mixed findings of a separate, but related, literature that studies the guidance of visual attention by WM contents. Specifically, we hypothesize that the linkage between WM representations and visual attention is governed by a time-shared cognitive resource that alternately refreshes internal (WM and selects external (visual attention information. If this were the case, WM content should guide visual attention (involuntarily, but only when there is time for it to be refreshed in an internal focus of attention. To provide an initial test for this hypothesis, we examined whether the amount of unoccupied time during a WM delay could impact the magnitude of attentional capture by WM contents. Participants were presented with a series of visual search trials while they maintained a WM cue for a delayed-recognition test. WM cues could coincide with the search target, a distracter, or neither. We varied both the number of searches to be performed, and the amount of available time to perform them. Slowing of visual search by a WM matching distracter—and facilitation by a matching target—were curtailed when the delay was filled with fast-paced (refreshing-preventing search trials, as was subsequent memory probe accuracy. WM content may, therefore, only capture visual attention when it can be refreshed, suggesting that internal (WM and external attention demands reciprocally impact one another because they share a limited resource. The TBRS rationale can thus be applied in a novel context to explain why WM contents capture attention, and under what conditions that effect should be observed.

Scalable printed electronics: an organic decoder addressing ferroelectric non-volatile memory

Science.gov (United States)

Ng, Tse Nga; Schwartz, David E.; Lavery, Leah L.; Whiting, Gregory L.; Russo, Beverly; Krusor, Brent; Veres, Janos; Bröms, Per; Herlogsson, Lars; Alam, Naveed; Hagel, Olle; Nilsson, Jakob; Karlsson, Christer

2012-01-01

Scalable circuits of organic logic and memory are realized using all-additive printing processes. A 3-bit organic complementary decoder is fabricated and used to read and write non-volatile, rewritable ferroelectric memory. The decoder-memory array is patterned by inkjet and gravure printing on flexible plastics. Simulation models for the organic transistors are developed, enabling circuit designs tolerant of the variations in printed devices. We explain the key design rules in fabrication of complex printed circuits and elucidate the performance requirements of materials and devices for reliable organic digital logic. PMID:22900143

Making the case that episodic recollection is attributable to operations occurring at retrieval rather than to content stored in a dedicated subsystem of long-term memory

Science.gov (United States)

Klein, Stanley B.

2013-01-01

Episodic memory often is conceptualized as a uniquely human system of long-term memory that makes available knowledge accompanied by the temporal and spatial context in which that knowledge was acquired. Retrieval from episodic memory entails a form of first–person subjectivity called autonoetic consciousness that provides a sense that a recollection was something that took place in the experiencer's personal past. In this paper I expand on this definition of episodic memory. Specifically, I suggest that (1) the core features assumed unique to episodic memory are shared by semantic memory, (2) episodic memory cannot be fully understood unless one appreciates that episodic recollection requires the coordinated function of a number of distinct, yet interacting, “enabling” systems. Although these systems—ownership, self, subjective temporality, and agency—are not traditionally viewed as memorial in nature, each is necessary for episodic recollection and jointly they may be sufficient, and (3) the type of subjective awareness provided by episodic recollection (autonoetic) is relational rather than intrinsic—i.e., it can be lost in certain patient populations, thus rendering episodic memory content indistinguishable from the content of semantic long-term memory. PMID:23378832

Making the Case that Episodic Recollection is Attributable to Operations Occurring at Retrieval rather than to Content Stored in a Dedicated Subsystem of Long-Term Memory

Directory of Open Access Journals (Sweden)

Stan eKlein

2013-02-01

Full Text Available Episodic memory often is conceptualized as a uniquely human system of long-term memory that makes available knowledge accompanied by the temporal and spatial context in which that knowledge was acquired. Retrieval from episodic memory entails a form of first–person subjectivity called autonoetic consciousness that provides a sense that a recollection was something that took place in the experiencer’s personal past. In this paper I expand on this definition of episodic memory. Specifically, I suggest that (a the core features assumed unique to episodic memory are shared by semantic memory, (b episodic memory cannot be fully understood unless one appreciates that episodic recollection requires the coordinated function of a number of distinct, yet interacting, enabling systems. Although these systems – ownership, self, subjective temporality, and agency – are not traditionally viewed as memorial in nature, each is necessary for episodic recollection and jointly they may be sufficient, and (c the type of subjective awareness provided by episodic recollection (autonoetic is relational rather than intrinsic – i.e., it can be lost in certain patient populations, thus rendering episodic memory content indistinguishable from the content of semantic long-term memory.

Transcranial magnetic stimulation reveals the content of visual short-term memory in the visual cortex.

Science.gov (United States)

Silvanto, Juha; Cattaneo, Zaira

2010-05-01

Cortical areas involved in sensory analysis are also believed to be involved in short-term storage of that sensory information. Here we investigated whether transcranial magnetic stimulation (TMS) can reveal the content of visual short-term memory (VSTM) by bringing this information to visual awareness. Subjects were presented with two random-dot displays (moving either to the left or to the right) and they were required to maintain one of these in VSTM. In Experiment 1, TMS was applied over the motion-selective area V5/MT+ above phosphene threshold during the maintenance phase. The reported phosphene contained motion features of the memory item, when the phosphene spatially overlapped with memory item. Specifically, phosphene motion was enhanced when the memory item moved in the same direction as the subjects' V5/MT+ baseline phosphene, whereas it was reduced when the motion direction of the memory item was incongruent with that of the baseline V5/MT+ phosphene. There was no effect on phosphene reports when there was no spatial overlap between the phosphene and the memory item. In Experiment 2, VSTM maintenance did not influence the appearance of phosphenes induced from the lateral occipital region. These interactions between VSTM maintenance and phosphene appearance demonstrate that activity in V5/MT+ reflects the motion qualities of items maintained in VSTM. Furthermore, these results also demonstrate that information in VSTM can modulate the pattern of visual activation reaching awareness, providing evidence for the view that overlapping neuronal populations are involved in conscious visual perception and VSTM. 2010. Published by Elsevier Inc.

Modeling the Role of Working Memory and Episodic Memory in Behavioral Tasks

OpenAIRE

Zilli, Eric A.; Hasselmo, Michael E.

2008-01-01

The mechanisms of goal-directed behavior have been studied using reinforcement learning theory, but these theoretical techniques have not often been used to address the role of memory systems in performing behavioral tasks. The present work addresses this shortcoming by providing a way in which working memory and episodic memory may be included in the reinforcement learning framework, then simulating the successful acquisition and performance of six behavioral tasks, drawn from or inspired by...

Addressing scientific literacy through content area reading and processes of scientific inquiry: What teachers report

Science.gov (United States)

Cooper, Susan J.

The purpose of this study was to interpret the experiences of secondary science teachers in Florida as they address the scientific literacy of their students through teaching content reading strategies and student inquiry skills. Knowledge of the successful integration of content reading and inquiry skills by experienced classroom teachers would be useful to many educators as they plan instruction to achieve challenging state and national standards for reading as well as science. The problem was investigated using grounded theory methodology. Open-ended questions were asked in three focus groups and six individual interviews that included teachers from various Florida school districts. The constant comparative approach was used to analyze the data. Initial codes were collapsed into categories to determine the conceptual relationships among the data. From this, the five core categories were determined to be Influencers, Issues, Perceptions, Class Routines, and Future Needs. These relate to the central phenomenon, Instructional Modifications, because teachers often described pragmatic and philosophical changes in their teaching as they deliberated to meet state standards in both reading and science. Although Florida's secondary science teachers have been asked to incorporate content reading strategies into their science instruction for the past several years, there was limited evidence of using these strategies to further student understanding of scientific processes. Most teachers saw little connection between reading and inquiry, other than the fact that students must know how to read to follow directions in the lab. Scientific literacy, when it was addressed by teachers, was approached mainly through class discussions, not reading. Teachers realized that students cannot learn secondary science content unless they read science text with comprehension; therefore the focus of reading instruction was on learning science content, not scientific literacy or student

Time-Predictable Virtual Memory

DEFF Research Database (Denmark)

Puffitsch, Wolfgang; Schoeberl, Martin

2016-01-01

Virtual memory is an important feature of modern computer architectures. For hard real-time systems, memory protection is a particularly interesting feature of virtual memory. However, current memory management units are not designed for time-predictability and therefore cannot be used...... in such systems. This paper investigates the requirements on virtual memory from the perspective of hard real-time systems and presents the design of a time-predictable memory management unit. Our evaluation shows that the proposed design can be implemented efficiently. The design allows address translation...... and address range checking in constant time of two clock cycles on a cache miss. This constant time is in strong contrast to the possible cost of a miss in a translation look-aside buffer in traditional virtual memory organizations. Compared to a platform without a memory management unit, these two additional...

Near-memory data reorganization engine

Science.gov (United States)

Gokhale, Maya; Lloyd, G. Scott

2018-05-08

A memory subsystem package is provided that has processing logic for data reorganization within the memory subsystem package. The processing logic is adapted to reorganize data stored within the memory subsystem package. In some embodiments, the memory subsystem package includes memory units, a memory interconnect, and a data reorganization engine ("DRE"). The data reorganization engine includes a stream interconnect and DRE units including a control processor and a load-store unit. The control processor is adapted to execute instructions to control a data reorganization. The load-store unit is adapted to process data move commands received from the control processor via the stream interconnect for loading data from a load memory address of a memory unit and storing data to a store memory address of a memory unit.

Improving the performance and energy-efficiency of virtual memory

OpenAIRE

Karakostas, Vasileios

2016-01-01

Virtual memory improves programmer productivity, enhances process security, and increases memory utilization. However, virtual memory requires an address translation from the virtual to the physical address space on every memory operation. Page-based implementations of virtual memory divide physical memory into fixed size pages, and use a per-process page table to map virtual pages to physical pages. The hardware key component for accelerating address translation is the Translation Lookasi...

Single memory with multiple shift register functionality

NARCIS (Netherlands)

2010-01-01

The present invention relates to a memory device comprising a memory (EM) having at least two predetermined register memory sections addressable by respective address ranges AS1-ASz) and at least one access port (P1-PZ) for providing access to said memory (EM). Furthermore, access control means (A)

Associative Memory Computing Power and Its Simulation

CERN Document Server

Volpi, G; The ATLAS collaboration

2014-01-01

The associative memory (AM) system is a computing device made of hundreds of AM ASICs chips designed to perform “pattern matching” at very high speed. Since each AM chip stores a data base of 130000 pre-calculated patterns and large numbers of chips can be easily assembled together, it is possible to produce huge AM banks. Speed and size of the system are crucial for real-time High Energy Physics applications, such as the ATLAS Fast TracKer (FTK) Processor. Using 80 million channels of the ATLAS tracker, FTK finds tracks within 100 micro seconds. The simulation of such a parallelized system is an extremely complex task if executed in commercial computers based on normal CPUs. The algorithm performance is limited, due to the lack of parallelism, and in addition the memory requirement is very large. In fact the AM chip uses a content addressable memory (CAM) architecture. Any data inquiry is broadcast to all memory elements simultaneously, thus data retrieval time is independent of the database size. The gr...

Associative Memory computing power and its simulation

CERN Document Server

Ancu, L S; The ATLAS collaboration; Britzger, D; Giannetti, P; Howarth, J W; Luongo, C; Pandini, C; Schmitt, S; Volpi, G

2014-01-01

The associative memory (AM) system is a computing device made of hundreds of AM ASICs chips designed to perform “pattern matching” at very high speed. Since each AM chip stores a data base of 130000 pre-calculated patterns and large numbers of chips can be easily assembled together, it is possible to produce huge AM banks. Speed and size of the system are crucial for real-time High Energy Physics applications, such as the ATLAS Fast TracKer (FTK) Processor. Using 80 million channels of the ATLAS tracker, FTK finds tracks within 100 micro seconds. The simulation of such a parallelized system is an extremely complex task if executed in commercial computers based on normal CPUs. The algorithm performance is limited, due to the lack of parallelism, and in addition the memory requirement is very large. In fact the AM chip uses a content addressable memory (CAM) architecture. Any data inquiry is broadcast to all memory elements simultaneously, thus data retrieval time is independent of the database size. The gr...

Architectures for a quantum random access memory

Science.gov (United States)

Giovannetti, Vittorio; Lloyd, Seth; Maccone, Lorenzo

2008-11-01

A random access memory, or RAM, is a device that, when interrogated, returns the content of a memory location in a memory array. A quantum RAM, or qRAM, allows one to access superpositions of memory sites, which may contain either quantum or classical information. RAMs and qRAMs with n -bit addresses can access 2n memory sites. Any design for a RAM or qRAM then requires O(2n) two-bit logic gates. At first sight this requirement might seem to make large scale quantum versions of such devices impractical, due to the difficulty of constructing and operating coherent devices with large numbers of quantum logic gates. Here we analyze two different RAM architectures (the conventional fanout and the “bucket brigade”) and propose some proof-of-principle implementations, which show that, in principle, only O(n) two-qubit physical interactions need take place during each qRAM call. That is, although a qRAM needs O(2n) quantum logic gates, only O(n) need to be activated during a memory call. The resulting decrease in resources could give rise to the construction of large qRAMs that could operate without the need for extensive quantum error correction.

Shape memory polymer hybrids of SBS/dl-PLA and their shape memory effects

International Nuclear Information System (INIS)

Zhang, Heng; Chen, Zhi; Zheng, Zheng; Zhu, Xiaomin; Wang, Haitao

2013-01-01

The hybrids of styrene-butadiene-styrene tri-block copolymer (SBS) and amorphous poly(dl-lactic acid) (dl-PLA) are found to exhibit shape memory effects, which gives an example of a dual-domain shape memory system consisting of an elastic domain and a thermo-switch domain. The dual-domain manner in this hybrid is studied by means of differential scanning calorimetry (DSC) and scanning electron microscope (SEM). Subsequently, the tensile test clarifies the interactions of the two domains on shape memory effects. As an elastic domain, SBS offers good shape recovery when its content exceeds 50 wt%. As a thermo-switch domain, dl-PLA triggers the shape memory effect at ca. 55 °C and offers good shape fixing when the content exceeds 30 wt%. An easy-to-do and easy-to-know feature of the hybrid is that the optimization of shape memory effect can be achieved by generating bicontinous phases of SBS and dl-PLA, in which the dl-PLA content ranges from 30 to 70 wt%. -- Highlights: ► The composite materials of SBS and amorphous dl-PLA were prepared by blending. ► A continuous domain was observed with the increasing content of dl-PLA. ► The composites exhibited shape memory effects.

Overwriting and intrusion in short-term memory.

Science.gov (United States)

Bancroft, Tyler D; Jones, Jeffery A; Ensor, Tyler M; Hockley, William E; Servos, Philip

2016-04-01

Studies of interference in working and short-term memory suggest that irrelevant information may overwrite the contents of memory or intrude into memory. While some previous studies have reported greater interference when irrelevant information is similar to the contents of memory than when it is dissimilar, other studies have reported greater interference for dissimilar distractors than for similar distractors. In the present study, we find the latter effect in a paradigm that uses auditory tones as stimuli. We suggest that the effects of distractor similarity to memory contents are mediated by the type of information held in memory, particularly the complexity or simplicity of information.

Static Memory Deduplication for Performance Optimization in Cloud Computing

Directory of Open Access Journals (Sweden)

Gangyong Jia

2017-04-01

Full Text Available In a cloud computing environment, the number of virtual machines (VMs on a single physical server and the number of applications running on each VM are continuously growing. This has led to an enormous increase in the demand of memory capacity and subsequent increase in the energy consumption in the cloud. Lack of enough memory has become a major bottleneck for scalability and performance of virtualization interfaces in cloud computing. To address this problem, memory deduplication techniques which reduce memory demand through page sharing are being adopted. However, such techniques suffer from overheads in terms of number of online comparisons required for the memory deduplication. In this paper, we propose a static memory deduplication (SMD technique which can reduce memory capacity requirement and provide performance optimization in cloud computing. The main innovation of SMD is that the process of page detection is performed offline, thus potentially reducing the performance cost, especially in terms of response time. In SMD, page comparisons are restricted to the code segment, which has the highest shared content. Our experimental results show that SMD efficiently reduces memory capacity requirement and improves performance. We demonstrate that, compared to other approaches, the cost in terms of the response time is negligible.

Static Memory Deduplication for Performance Optimization in Cloud Computing.

Science.gov (United States)

Jia, Gangyong; Han, Guangjie; Wang, Hao; Yang, Xuan

2017-04-27

In a cloud computing environment, the number of virtual machines (VMs) on a single physical server and the number of applications running on each VM are continuously growing. This has led to an enormous increase in the demand of memory capacity and subsequent increase in the energy consumption in the cloud. Lack of enough memory has become a major bottleneck for scalability and performance of virtualization interfaces in cloud computing. To address this problem, memory deduplication techniques which reduce memory demand through page sharing are being adopted. However, such techniques suffer from overheads in terms of number of online comparisons required for the memory deduplication. In this paper, we propose a static memory deduplication (SMD) technique which can reduce memory capacity requirement and provide performance optimization in cloud computing. The main innovation of SMD is that the process of page detection is performed offline, thus potentially reducing the performance cost, especially in terms of response time. In SMD, page comparisons are restricted to the code segment, which has the highest shared content. Our experimental results show that SMD efficiently reduces memory capacity requirement and improves performance. We demonstrate that, compared to other approaches, the cost in terms of the response time is negligible.

Direct access inter-process shared memory

Science.gov (United States)

Brightwell, Ronald B; Pedretti, Kevin; Hudson, Trammell B

2013-10-22

A technique for directly sharing physical memory between processes executing on processor cores is described. The technique includes loading a plurality of processes into the physical memory for execution on a corresponding plurality of processor cores sharing the physical memory. An address space is mapped to each of the processes by populating a first entry in a top level virtual address table for each of the processes. The address space of each of the processes is cross-mapped into each of the processes by populating one or more subsequent entries of the top level virtual address table with the first entry in the top level virtual address table from other processes.

Developmental Differences in Recall and Recognition: The Relationship between Rehearsal and Memory as Test Expectation Changes

Science.gov (United States)

Naus, Mary J.; And Others

1977-01-01

An overt rehearsal procedure was used to study the relationship between 48 third- and 48 sixth-grade children's rehearsal strategies and their memory performance under difficult conditions of test expectation. This study addressed the question of why active rehearsal content results in superior recall performances. (MS)

Partitioned key-value store with atomic memory operations

Energy Technology Data Exchange (ETDEWEB)

Bent, John M.; Faibish, Sorin; Grider, Gary

2017-02-07

A partitioned key-value store is provided that supports atomic memory operations. A server performs a memory operation in a partitioned key-value store by receiving a request from an application for at least one atomic memory operation, the atomic memory operation comprising a memory address identifier; and, in response to the atomic memory operation, performing one or more of (i) reading a client-side memory location identified by the memory address identifier and storing one or more key-value pairs from the client-side memory location in a local key-value store of the server; and (ii) obtaining one or more key-value pairs from the local key-value store of the server and writing the obtained one or more key-value pairs into the client-side memory location identified by the memory address identifier. The server can perform functions obtained from a client-side memory location and return a result to the client using one or more of the atomic memory operations.

System and method for programmable bank selection for banked memory subsystems

Energy Technology Data Exchange (ETDEWEB)

Blumrich, Matthias A. (Ridgefield, CT); Chen, Dong (Croton on Hudson, NY); Gara, Alan G. (Mount Kisco, NY); Giampapa, Mark E. (Irvington, NY); Hoenicke, Dirk (Seebruck-Seeon, DE); Ohmacht, Martin (Yorktown Heights, NY); Salapura, Valentina (Chappaqua, NY); Sugavanam, Krishnan (Mahopac, NY)

2010-09-07

A programmable memory system and method for enabling one or more processor devices access to shared memory in a computing environment, the shared memory including one or more memory storage structures having addressable locations for storing data. The system comprises: one or more first logic devices associated with a respective one or more processor devices, each first logic device for receiving physical memory address signals and programmable for generating a respective memory storage structure select signal upon receipt of pre-determined address bit values at selected physical memory address bit locations; and, a second logic device responsive to each of the respective select signal for generating an address signal used for selecting a memory storage structure for processor access. The system thus enables each processor device of a computing environment memory storage access distributed across the one or more memory storage structures.

Working memory and executive function: the influence of content and load on the control of attention.

Science.gov (United States)

Hester, Robert; Garavan, Hugh

2005-03-01

In a series of three experiments, increasing working memory (WM) load was demonstrated to reduce the executive control of attention, measured via task-switching and inhibitory control paradigms. Uniquely, our paradigms allowed comparison of the ability to exert executive control when the stimulus was either part of the currently rehearsed memory set or an unrelated distractor item. The results demonstrated a content-specific effect-insofar as switching attention away from, or exerting inhibitory control over, items currently held in WM was especially difficult-compounded by increasing WM load. This finding supports the attentional control theory that active maintenance of competing task goals is critical to executive function and WM capacity; however, it also suggests that the increased salience provided to the contents of WM through active rehearsal exerts a content-specific influence on attentional control. These findings are discussed in relation to cue-induced ruminations, where active rehearsal of evocative information (e.g., negative thoughts in depression or drug-related thoughts in addiction) in WM typically results from environmental cuing. The present study has demonstrated that when information currently maintained in WM is reencountered, it is harder to exert executive control over it. The difficulty with suppressing the processing of these stimuli presumably reinforces the maintenance of these items in WM, due to the greater level of attention they are afforded, and may help to explain how the cue-induced craving/rumination cycle is perpetuated.

Conditional load and store in a shared memory

Science.gov (United States)

Blumrich, Matthias A; Ohmacht, Martin

2015-02-03

A method, system and computer program product for implementing load-reserve and store-conditional instructions in a multi-processor computing system. The computing system includes a multitude of processor units and a shared memory cache, and each of the processor units has access to the memory cache. In one embodiment, the method comprises providing the memory cache with a series of reservation registers, and storing in these registers addresses reserved in the memory cache for the processor units as a result of issuing load-reserve requests. In this embodiment, when one of the processor units makes a request to store data in the memory cache using a store-conditional request, the reservation registers are checked to determine if an address in the memory cache is reserved for that processor unit. If an address in the memory cache is reserved for that processor, the data are stored at this address.

Frontal lobe damage impairs process and content in semantic memory: evidence from category-specific effects in progressive non-fluent aphasia.

Science.gov (United States)

Reilly, Jamie; Rodriguez, Amy D; Peelle, Jonathan E; Grossman, Murray

2011-06-01

Portions of left inferior frontal cortex have been linked to semantic memory both in terms of the content of conceptual representation (e.g., motor aspects in an embodied semantics framework) and the cognitive processes used to access these representations (e.g., response selection). Progressive non-fluent aphasia (PNFA) is a neurodegenerative condition characterized by progressive atrophy of left inferior frontal cortex. PNFA can, therefore, provide a lesion model for examining the impact of frontal lobe damage on semantic processing and content. In the current study we examined picture naming in a cohort of PNFA patients across a variety of semantic categories. An embodied approach to semantic memory holds that sensorimotor features such as self-initiated action may assume differential importance for the representation of manufactured artifacts (e.g., naming hand tools). Embodiment theories might therefore predict that patients with frontal damage would be differentially impaired on manufactured artifacts relative to natural kinds, and this prediction was borne out. We also examined patterns of naming errors across a wide range of semantic categories and found that naming error distributions were heterogeneous. Although PNFA patients performed worse overall on naming manufactured artifacts, there was no reliable relationship between anomia and manipulability across semantic categories. These results add to a growing body of research arguing against a purely sensorimotor account of semantic memory, suggesting instead a more nuanced balance of process and content in how the brain represents conceptual knowledge. Copyright © 2010 Elsevier Srl. All rights reserved.

Content Analysis of Memory and Memory-Related Research Studies on Children with Hearing Loss

Science.gov (United States)

Dogan, Murat; Hasanoglu, Gülcihan

2016-01-01

Memory plays a profound role in explaining language development, academic learning, and learning disabilities. Even though there is a large body of research on language development, literacy skills, other academic skills, and intellectual characteristics of children with hearing loss, there is no holistic study on their memory processes.…

The effect of cue content on retrieval from autobiographical memory.

Science.gov (United States)

Uzer, Tugba; Brown, Norman R

2017-01-01

It has long been argued that personal memories are usually generated in an effortful search process in word-cueing studies. However, recent research (Uzer, Lee, & Brown, 2012) shows that direct retrieval of autobiographical memories, in response to word cues, is common. This invites the question of whether direct retrieval phenomenon is generalizable beyond the standard laboratory paradigm. Here we investigated prevalence of direct retrieval of autobiographical memories cued by specific and individuated cues versus generic cues. In Experiment 1, participants retrieved memories in response to cues from their own life (e.g., the names of friends) and generic words (e.g., chair). In Experiment 2, participants provided their personal cues two or three months prior to coming to the lab (min: 75days; max: 100days). In each experiment, RT was measured and participants reported whether memories were directly retrieved or generated on each trial. Results showed that personal cues elicited a high rate of direct retrieval. Personal cues were more likely to elicit direct retrieval than generic word cues, and as a consequence, participants responded faster, on average, to the former than to the latter. These results challenge the constructive view of autobiographical memory and suggest that autobiographical memories consist of pre-stored event representations, which are largely governed by associative mechanisms. These demonstrations offer theoretically interesting questions such as why are we not overwhelmed with directly retrieved memories cued by everyday familiar surroundings? Copyright © 2016 Elsevier B.V. All rights reserved.

A new approach for implementation of associative memory using volume holographic materials

Science.gov (United States)

Habibi, Mohammad; Pashaie, Ramin

2012-02-01

Associative memory, also known as fault tolerant or content-addressable memory, has gained considerable attention in last few decades. This memory possesses important advantages over the more common random access memories since it provides the capability to correct faults and/or partially missing information in a given input pattern. There is general consensus that optical implementation of connectionist models and parallel processors including associative memory has a better record of success compared to their electronic counterparts. In this article, we describe a novel optical implementation of associative memory which not only has the advantage of all optical learning and recalling capabilities, it can also be realized easily. We present a new approach, inspired by tomographic imaging techniques, for holographic implementation of associative memories. In this approach, a volume holographic material is sandwiched within a matrix of inputs (optical point sources) and outputs (photodetectors). The memory capacity is realized by the spatial modulation of refractive index of the holographic material. Constructing the spatial distribution of the refractive index from an array of known inputs and outputs is formulated as an inverse problem consisting a set of linear integral equations.

The time course of working memory effects on visual attention differs depending on memory type

NARCIS (Netherlands)

Dombrowe, I.; Olivers, C.N.L.; Donk, M.

2010-01-01

Previous work has generated inconsistent results with regard to what extent working memory (WM) content guides visual attention. Some studies found effects of easy to verbalize stimuli, whereas others only found an influence of visual memory content. To resolve this, we compared the time courses of

Environmental context-dependent memory: a review and meta-analysis.

Science.gov (United States)

Smith, S M; Vela, E

2001-06-01

To address questions about human memory's dependence on the coincidental environmental contexts in which events occur, we review studies of incidental environmental context-dependent memory in humans and report a meta-analysis. Our theoretical approach to the issue stems from Glenberg's (1997) contention that introspective thought (e.g., remembering, conceptualizing) requires cognitive resources normally used to represent the immediate environment. We propose that if tasks encourage processing of noncontextual information (i.e., introspective thought) at input and/or at test, then both learning and memory will be less dependent on the ambient environmental contexts in which those activities occur. The meta-analysis showed that across all studies, environmental context effects were reliable, and furthermore, that the use of noncontextual cues during learning (overshadowing) and at test (outshining), as well as mental reinstatement of appropriate context cues at test, all reduce the effect of environmental manipulations. We conclude that environmental context-dependent memory effects are less likely to occur under conditions in which the immediate environment is likely to be suppressed.

Synaesthesia is linked to more vivid and detailed content of autobiographical memories and less fading of childhood memories.

Science.gov (United States)

Chin, Taylor; Ward, Jamie

2017-12-15

People with synaesthesia have enhanced memory on a wide range of laboratory tests of episodic memory, but very little is known about their real-world memory. This study used a standard measure of autobiographical remembering (the Autobiographical Memory Questionnaire, AMQ) considering four constructs (Recollection, Belief, Impact and Rehearsal) and two time periods (recent memories from adulthood, remote memories from childhood). Synaesthetes reported more Recollection (e.g., sensory detail) and Belief (e.g., confidence) which interacted with time, such that remote memories are reported to be comparatively better preserved in synaesthetes. This cannot be explained by synaesthetes recalling more salient episodes (the groups did not differ in Impact). It suggests instead that childhood memories have a special status in synaesthesia that reflects the different neurodevelopmental trajectory of this group. With regards to Rehearsal, controls tended to report that more recent memories tend to resurface (i.e., adulthood > childhood), but the synaesthetes showed the opposite dissociation (i.e., childhood > adulthood).

Tracing Cultural Memory

DEFF Research Database (Denmark)

Wiegand, Frauke Katharina

by their encounters – to address a question that thirty years of ground - breaking research into memory has not yet sufficiently answered: What can we learn about the dynamics of cultural memory by examining mundane accounts of touristic encounters with sites of memory? From Blaavand Beach in Western Denmark......We encounter, relate to and make use of our past and that of others in multifarious and increasingly mobile ways. Tourism is one of the main paths for encountering sites of memory. This thesis examines tourists’ creative appropriations of sites of memory – the objects and future memories inspired...... of memory. They highlight the role of mundane uses of the past and indicate the need for cross - disciplinary research on the visual and on memory...

Eye movements during the recollection of text information reflect content rather than the text itself

DEFF Research Database (Denmark)

Traub, Franziska; Johansson, Roger; Holmqvist, Kenneth

Several studies have reported that spontaneous eye movements occur when visuospatial information is recalled from memory. Such gazes closely reflect the content and spatial relations from the original scene layout (e.g., Johansson et al., 2012). However, when someone has originally read a scene....... Recollection was performed orally while gazing at a blank screen. Results demonstrate that participant’s gaze patterns during recall more closely reflect the spatial layout of the scene than the physical locations of the text. Memory data provide evidence that mental models representing either the situation...... description, the memory of the physical layout of the text itself might compete with the memory of the spatial arrangement of the described scene. The present study was designed to address this fundamental issue by having participants read scene descriptions that where manipulated to be either congruent...

Transcranial magnetic stimulation of visual cortex in memory: cortical state, interference and reactivation of visual content in memory.

Science.gov (United States)

van de Ven, Vincent; Sack, Alexander T

2013-01-01

Memory for perceptual events includes the neural representation of the sensory information at short or longer time scales. Recent transcranial magnetic stimulation (TMS) studies of human visual cortex provided evidence that sensory cortex contributes to memory functions. In this review, we provide an exhaustive overview of these studies and ascertain how well the available evidence supports the idea of a causal role of sensory cortex in memory retention and retrieval. We discuss the validity and implications of the studies using a number of methodological and theoretical criteria that are relevant for brain stimulation of visual cortex. While most studies applied TMS to visual cortex to interfere with memory functions, a handful of pioneering studies used TMS to 'reactivate' memories in visual cortex. Interestingly, similar effects of TMS on memory were found in different memory tasks, which suggests that different memory systems share a neural mechanism of memory in visual cortex. At the same time, this neural mechanism likely interacts with higher order brain areas. Based on this overview and evaluation, we provide a first attempt to an integrative framework that describes how sensory processes contribute to memory in visual cortex, and how higher order areas contribute to this mechanism. Copyright © 2012 Elsevier B.V. All rights reserved.

The Influence of Direct and Indirect Speech on Source Memory

Directory of Open Access Journals (Sweden)

Anita Eerland

2018-02-01

Full Text Available People perceive the same situation described in direct speech (e.g., John said, “I like the food at this restaurant” as more vivid and perceptually engaging than described in indirect speech (e.g., John said that he likes the food at the restaurant. So, if direct speech enhances the perception of vividness relative to indirect speech, what are the effects of using indirect speech? In four experiments, we examined whether the use of direct and indirect speech influences the comprehender’s memory for the identity of the speaker. Participants read a direct or an indirect speech version of a story and then addressed statements to one of the four protagonists of the story in a memory task. We found better source memory at the level of protagonist gender after indirect than direct speech (Exp. 1–3. When the story was rewritten to make the protagonists more distinctive, we also found an effect of speech type on source memory at the level of the individual, with better memory after indirect than direct speech (Exp. 3–4. Memory for the content of the story, however, was not influenced by speech type (Exp. 4. While previous research showed that direct speech may enhance memory for how something was said, we conclude that indirect speech enhances memory for who said what.

Cognitive memory.

Science.gov (United States)

Widrow, Bernard; Aragon, Juan Carlos

2013-05-01

Regarding the workings of the human mind, memory and pattern recognition seem to be intertwined. You generally do not have one without the other. Taking inspiration from life experience, a new form of computer memory has been devised. Certain conjectures about human memory are keys to the central idea. The design of a practical and useful "cognitive" memory system is contemplated, a memory system that may also serve as a model for many aspects of human memory. The new memory does not function like a computer memory where specific data is stored in specific numbered registers and retrieval is done by reading the contents of the specified memory register, or done by matching key words as with a document search. Incoming sensory data would be stored at the next available empty memory location, and indeed could be stored redundantly at several empty locations. The stored sensory data would neither have key words nor would it be located in known or specified memory locations. Sensory inputs concerning a single object or subject are stored together as patterns in a single "file folder" or "memory folder". When the contents of the folder are retrieved, sights, sounds, tactile feel, smell, etc., are obtained all at the same time. Retrieval would be initiated by a query or a prompt signal from a current set of sensory inputs or patterns. A search through the memory would be made to locate stored data that correlates with or relates to the prompt input. The search would be done by a retrieval system whose first stage makes use of autoassociative artificial neural networks and whose second stage relies on exhaustive search. Applications of cognitive memory systems have been made to visual aircraft identification, aircraft navigation, and human facial recognition. Concerning human memory, reasons are given why it is unlikely that long-term memory is stored in the synapses of the brain's neural networks. Reasons are given suggesting that long-term memory is stored in DNA or RNA

Early selection versus late correction: Age-related differences in controlling working memory contents.

Science.gov (United States)

Schwarzkopp, Tina; Mayr, Ulrich; Jost, Kerstin

2016-08-01

We examined whether a reduced ability to ignore irrelevant information is responsible for the age-related decline of working memory (WM) functions. By means of event-related brain potentials, we will show that filtering is not out of service in older adults but shifted to a later processing stage. Participants performed a visual short-term memory task (change-detection task) in which targets were presented along with distractors. To allow early selection, a cue was presented in advance of each display, indicating where the targets were to appear. Despite this relatively easy selection criterion, older adults' filtering was delayed as indicated by the amplitude pattern of the contralateral delay activity. Importantly, WM-equated younger adults did not show a delay indicating that the delay is specific to older adults and not a general phenomenon that comes with low WM capacity. Moreover, the analysis of early visual potentials revealed qualitatively different perceptual/attentional processing between the age groups. Young adults exhibited stronger distractor sensitivity that in turn facilitated filtering. Older adults, in contrast, seemed to initially store distractors and to suppress them after the fact. These early selection versus late-correction modes suggest an age-related shift in the strategy to control the contents of WM. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Targeted Memory Reactivation during Sleep Adaptively Promotes the Strengthening or Weakening of Overlapping Memories.

Science.gov (United States)

Oyarzún, Javiera P; Morís, Joaquín; Luque, David; de Diego-Balaguer, Ruth; Fuentemilla, Lluís

2017-08-09

System memory consolidation is conceptualized as an active process whereby newly encoded memory representations are strengthened through selective memory reactivation during sleep. However, our learning experience is highly overlapping in content (i.e., shares common elements), and memories of these events are organized in an intricate network of overlapping associated events. It remains to be explored whether and how selective memory reactivation during sleep has an impact on these overlapping memories acquired during awake time. Here, we test in a group of adult women and men the prediction that selective memory reactivation during sleep entails the reactivation of associated events and that this may lead the brain to adaptively regulate whether these associated memories are strengthened or pruned from memory networks on the basis of their relative associative strength with the shared element. Our findings demonstrate the existence of efficient regulatory neural mechanisms governing how complex memory networks are shaped during sleep as a function of their associative memory strength. SIGNIFICANCE STATEMENT Numerous studies have demonstrated that system memory consolidation is an active, selective, and sleep-dependent process in which only subsets of new memories become stabilized through their reactivation. However, the learning experience is highly overlapping in content and thus events are encoded in an intricate network of related memories. It remains to be explored whether and how memory reactivation has an impact on overlapping memories acquired during awake time. Here, we show that sleep memory reactivation promotes strengthening and weakening of overlapping memories based on their associative memory strength. These results suggest the existence of an efficient regulatory neural mechanism that avoids the formation of cluttered memory representation of multiple events and promotes stabilization of complex memory networks. Copyright © 2017 the authors 0270-6474/17/377748-11$15.00/0.

A general model for memory interference in a multiprocessor system with memory hierarchy

Science.gov (United States)

Taha, Badie A.; Standley, Hilda M.

1989-01-01

The problem of memory interference in a multiprocessor system with a hierarchy of shared buses and memories is addressed. The behavior of the processors is represented by a sequence of memory requests with each followed by a determined amount of processing time. A statistical queuing network model for determining the extent of memory interference in multiprocessor systems with clusters of memory hierarchies is presented. The performance of the system is measured by the expected number of busy memory clusters. The results of the analytic model are compared with simulation results, and the correlation between them is found to be very high.

Catching a glimpse of working memory: top-down capture as a tool for measuring the content of the mind.

Science.gov (United States)

Lange, Nicholas D; Thomas, Rick P; Buttaccio, Daniel R; Davelaar, Eddy J

2012-11-01

This article outlines a methodology for probing working memory (WM) content in high-level cognitive tasks (e.g., decision making, problem solving, and memory retrieval) by capitalizing on attentional and oculomotor biases evidenced in top-down capture paradigms. This method would be of great use, as it could measure the information resident in WM at any point in a task and, hence, track information use over time as tasks dynamically evolve. Above and beyond providing a measure of information occupancy in WM, such a method would benefit from sensitivity to the specific activation levels of individual items in WM. This article additionally forwards a novel fusion of standard free recall and visual search paradigms in an effort to assess the sensitivity of eye movements in top-down capture, on which this new measurement technique relies, to item-specific memory activation (ISMA). The results demonstrate eye movement sensitivity to ISMA in some, but not all, cases.

Data Movement Dominates: Advanced Memory Technology to Address the Real Exascale Power Problem

Energy Technology Data Exchange (ETDEWEB)

Bergman, Keren

2014-08-28

Energy is the fundamental barrier to Exascale supercomputing and is dominated by the cost of moving data from one point to another, not computation. Similarly, performance is dominated by data movement, not computation. The solution to this problem requires three critical technologies: 3D integration, optical chip-to-chip communication, and a new communication model. The central goal of the Sandia led "Data Movement Dominates" project aimed to develop memory systems and new architectures based on these technologies that have the potential to lower the cost of local memory accesses by orders of magnitude and provide substantially more bandwidth. Only through these transformational advances can future systems reach the goals of Exascale computing with a manageable power budgets. The Sandia led team included co-PIs from Columbia University, Lawrence Berkeley Lab, and the University of Maryland. The Columbia effort of Data Movement Dominates focused on developing a physically accurate simulation environment and experimental verification for optically-connected memory (OCM) systems that can enable continued performance scaling through high-bandwidth capacity, energy-efficient bit-rate transparency, and time-of-flight latency. With OCM, memory device parallelism and total capacity can scale to match future high-performance computing requirements without sacrificing data-movement efficiency. When we consider systems with integrated photonics, links to memory can be seamlessly integrated with the interconnection network-in a sense, memory becomes a primary aspect of the interconnection network. At the core of the Columbia effort, toward expanding our understanding of OCM enabled computing we have created an integrated modeling and simulation environment that uniquely integrates the physical behavior of the optical layer. The PhoenxSim suite of design and software tools developed under this effort has enabled the co-design of and performance evaluation photonics-enabled OCM

External details revisited - A new taxonomy for coding 'non-episodic' content during autobiographical memory retrieval.

Science.gov (United States)

Strikwerda-Brown, Cherie; Mothakunnel, Annu; Hodges, John R; Piguet, Olivier; Irish, Muireann

2018-04-24

Autobiographical memory (ABM) is typically held to comprise episodic and semantic elements, with the vast majority of studies to date focusing on profiles of episodic details in health and disease. In this context, 'non-episodic' elements are often considered to reflect semantic processing or are discounted from analyses entirely. Mounting evidence suggests that rather than reflecting one unitary entity, semantic autobiographical information may contain discrete subcomponents, which vary in their relative degree of semantic or episodic content. This study aimed to (1) review the existing literature to formally characterize the variability in analysis of 'non-episodic' content (i.e., external details) on the Autobiographical Interview and (2) use these findings to create a theoretically grounded framework for coding external details. Our review exposed discrepancies in the reporting and interpretation of external details across studies, reinforcing the need for a new, consistent approach. We validated our new external details scoring protocol (the 'NExt' taxonomy) in patients with Alzheimer's disease (n = 18) and semantic dementia (n = 13), and 20 healthy older Control participants and compared profiles of the NExt subcategories across groups and time periods. Our results revealed increased sensitivity of the NExt taxonomy in discriminating between ABM profiles of patient groups, when compared to traditionally used internal and external detail metrics. Further, remote and recent autobiographical memories displayed distinct compositions of the NExt detail types. This study is the first to provide a fine-grained and comprehensive taxonomy to parse external details into intuitive subcategories and to validate this protocol in neurodegenerative disorders. © 2018 The British Psychological Society.

Addressing Working Memory in Children with Autism through Behavioral Intervention

Science.gov (United States)

Baltruschat, Lisa; Hasselhorn, Marcus; Tarbox, Jonathan; Dixon, Dennis R.; Najdowski, Adel C.; Mullins, Ryan D.; Gould, Evelyn R.

2011-01-01

Children with autism often struggle with executive function (EF) deficits, particularly with regard to working memory (WM). Despite the documented deficits in these areas, very little controlled research has evaluated treatments for remediation of EF or WM deficits in children with autism. This study examined the use of positive reinforcement for…

Flexible NAND-Like Organic Ferroelectric Memory Array

NARCIS (Netherlands)

Kam, B.; Ke, T.H.; Chasin, A.; Tyagi, M.; Cristoferi, C.; Tempelaars, K.; Breemen, A.J.J.M. van; Myny, K.; Schols, S.; Genoe, J.; Gelinck, G.H.; Heremans, P.

2014-01-01

We present a memory array of organic ferroelectric field-effect transistors (OFeFETs) on flexible substrates. The OFeFETs are connected serially, similar to the NAND architecture of flash memory, which offers the highest memory density of transistor memories. We demonstrate a reliable addressing

Scheduling support for transactional memory contention management

DEFF Research Database (Denmark)

Maldonado, Walther; Marler, Patrick; Felber, Pascal

2010-01-01

Transactional Memory (TM) is considered as one of the most promising paradigms for developing concurrent applications. TM has been shown to scale well on >multiple cores when the data access pattern behaves "well," i.e., when few conflicts are induced. In contrast, data patterns with frequent wri...

Looking for episodic memory in animals and young children: prospects for a new minimalism.

Science.gov (United States)

Clayton, Nicola S; Russell, James

2009-09-01

Because animals and young children cannot be interrogated about their experiences it is difficult to conduct research into their episodic memories. The approach to this issue adopted by Clayton and Dickinson [Clayton, N. S., & Dickinson, A. (1998). Episodic-like memory during cache recovery by scrub jays. Nature, 395, 272-274] was to take a conceptually minimalist definition of episodic memory, in terms of integrating information about what was done where and when [Tulving, E. (1972). Episodic and semantic memory. In E. Tulving, & W. Donaldson (Eds.), Organisation of memory (pp. 381-403). New York: Academic Press], and to refer to such memories as 'episodic-like'. Some claim, however, that because animals supposedly lack the conceptual abilities necessary for episodic recall one should properly call these memories 'semantic'. We address this debate with a novel approach to episodic memory, which is minimalist insofar as it focuses on the non-conceptual content of a re-experienced situation. It rests on Kantian assumptions about the necessary 'perspectival' features of any objective experience or re-experience. We show how adopting this perspectival approach can render an episodic interpretation of the animal data more plausible and can also reveal patterns in the mosaic of developmental evidence for episodic memory in humans.

Does emotional memory enhancement assist the memory-impaired?

Directory of Open Access Journals (Sweden)

Lucas S. Broster

2012-03-01

Full Text Available We review recent work on emotional memory enhancement in older adults and patients with mild cognitive impairment or Alzheimer dementia and evaluate the viability of incorporating emotional components into cognitive rehabilitation for these groups. First, we identify converging evidence regarding the effects of emotional valence on working memory in healthy aging. Second, we introduce work that suggests a more complex role for emotional memory enhancement in aging and identify a model capable of unifying disparate research findings. Third, we identify neuroimaging evidence that the amygdala may play a key role in mediating emotional memory enhancement in mild cognitive impairment and early Alzheimer dementia. Finally, we assess the theoretical feasibility of incorporating emotional content into cognitive rehabilitation given all available evidence.

Attending and Inhibiting Stimuli That Match the Contents of Visual Working Memory: Evidence from Eye Movements and Pupillometry (2015 GDR Vision meeting)

OpenAIRE

Mathôt, Sebastiaan; Heusden, Elle van; Stigchel, Stefan Van der

2015-01-01

Slides for: Mathôt, S., & Van Heusden, E., & Van der Stigchel, S. (2015, Dec). Attending and Inhibiting Stimuli That Match the Contents of Visual Working Memory: Evidence from Eye Movements and Pupillometry. Talk presented at the GDR Vision Meething, Grenoble, France.

Interaction of sleep and emotional content on the production of false memories.

Science.gov (United States)

McKeon, Shannon; Pace-Schott, Edward F; Spencer, Rebecca M C

2012-01-01

Sleep benefits veridical memories, resulting in superior recall relative to off-line intervals spent awake. Sleep also increases false memory recall in the Deese-Roediger-McDermott (DRM) paradigm. Given the suggestion that emotional veridical memories are prioritized for consolidation over sleep, here we examined whether emotion modulates sleep's effect on false memory formation. Participants listened to semantically related word lists lacking a critical lure representing each list's "gist." Free recall was tested after 12 hours containing sleep or wake. The Sleep group recalled more studied words than the Wake group but only for emotionally neutral lists. False memories of both negative and neutral critical lures were greater following sleep relative to wake. Morning and Evening control groups (20-minute delay) did not differ ruling out circadian accounts for these differences. These results support the adaptive function of sleep in both promoting the consolidation of veridical declarative memories and in extracting unifying aspects from memory details.

Interaction of sleep and emotional content on the production of false memories.

Directory of Open Access Journals (Sweden)

Shannon McKeon

Full Text Available Sleep benefits veridical memories, resulting in superior recall relative to off-line intervals spent awake. Sleep also increases false memory recall in the Deese-Roediger-McDermott (DRM paradigm. Given the suggestion that emotional veridical memories are prioritized for consolidation over sleep, here we examined whether emotion modulates sleep's effect on false memory formation. Participants listened to semantically related word lists lacking a critical lure representing each list's "gist." Free recall was tested after 12 hours containing sleep or wake. The Sleep group recalled more studied words than the Wake group but only for emotionally neutral lists. False memories of both negative and neutral critical lures were greater following sleep relative to wake. Morning and Evening control groups (20-minute delay did not differ ruling out circadian accounts for these differences. These results support the adaptive function of sleep in both promoting the consolidation of veridical declarative memories and in extracting unifying aspects from memory details.

A comparison of three types of autobiographical memories in old-old age: first memories, pivotal memories and traumatic memories.

Science.gov (United States)

Cohen-Mansfield, Jiska; Shmotkin, Dov; Eyal, Nitza; Reichental, Yael; Hazan, Haim

2010-01-01

Autobiographical memory enables us to construct a personal narrative through which we identify ourselves. Especially important are memories of formative events. This study describes autobiographical memories of people who have reached old-old age (85 years and above), studying 3 types of memories of particular impact on identity and adaptation: first memories, pivotal memories and traumatic memories. In this paper, we examine the content, characteristic themes and environments, and structural characteristics of each of the 3 types of memory. The participants were 26 persons from a larger longitudinal study with an average age of 91 years; half were men and the other half women. The study integrated qualitative and quantitative tools. An open-ended questionnaire included questions about the participants' life story as well as questions about the 3 types of memories. The responses were rated by 3 independent judges on dimensions of central themes and structural characteristics. First memories had a more positive emotional tone, more references to characters from the participant's social circle, a stronger sense of group belonging, and a more narrative style than the other types of memories. Pivotal and traumatic memories were described as more personal than first memories. The 3 types of memories reflect different stages in life development, which together form a sense of identity. They present experiences from the past on select themes, which may assist in the complex task of coping with the difficulties and limitations that advanced old age presents. Future research should examine the functional role of those memories and whether they enable the old-old to support selfhood in the challenging period of last changes and losses. Copyright © 2010 S. Karger AG, Basel.

Memory-cenric video processing

NARCIS (Netherlands)

Beric, A.; Meerbergen, van J.; Haan, de G.; Sethuraman, R.

2008-01-01

This work presents a domain-specific memory subsystem based on a two-level memory hierarchy. It targets the application domain of video post-processing applications including video enhancement and format conversion. These applications are based on motion compensation and/or broad class of content

Visual input that matches the content of vist of visual working memory requires less (not faster) evidence sampling to reach conscious access

NARCIS (Netherlands)

Gayet, S.; van Maanen, L.; Heilbron, M.; Paffen, C.L.E.; Van Der Stigchel, S.

2016-01-01

The content of visual working memory (VWM) affects the processing of concurrent visual input. Recently, it has been demonstrated that stimuli are released from interocular suppression faster when they match rather than mismatch a color that is memorized for subsequent recall. In order to investigate

[Memory and the executive functions].

Science.gov (United States)

Tirapu-Ustárroz, J; Muñoz-Céspedes, J M

The terms 'executive functioning' or 'executive control' refer to a set of mechanisms involved in the improvement of cognitive processes to guide them towards the resolution of complex problems. Both the frontal lobes, acting as structure, and the executive processes, acting as function, work with memory contents, operating with information placed in the diencephalic structures and in the medial temporal lobe. Generally, we can state that many works find an association between frontal damage and specific memory shortages like working memory deficit, metamemory problems, source amnesia, or difficulties in the prospective memory. This paper is a critical review of the working memory concept and proposes a new term: the attentional operative system that works with memory contents. Concerning the metamemory, the frontal lobes are essential for monitoring processes in general and for 'the feeling of knowing' kind of judgements in particular. Patients suffering prefrontal damage show serious problems to remember the information source. Thus, the information is rightly remembered but the spatiotemporal context where that information was learned has been forgotten. Finally, the prospective memory deals with remembering to make something in a particular moment in the future and performing the plan previously drawn up.

Short-term memory in Down syndrome: applying the working memory model.

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Jarrold, C; Baddeley, A D

2001-10-01

This paper is divided into three sections. The first reviews the evidence for a verbal short-term memory deficit in Down syndrome. Existing research suggests that short-term memory for verbal information tends to be impaired in Down syndrome, in contrast to short-term memory for visual and spatial material. In addition, problems of hearing or speech do not appear to be a major cause of difficulties on tests of verbal short-term memory. This suggests that Down syndrome is associated with a specific memory problem, which we link to a potential deficit in the functioning of the 'phonological loop' of Baddeley's (1986) model of working memory. The second section considers the implications of a phonological loop problem. Because a reasonable amount is known about the normal functioning of the phonological loop, and of its role in language acquisition in typical development, we can make firm predictions as to the likely nature of the short-term memory problem in Down syndrome, and its consequences for language learning. However, we note that the existing evidence from studies with individuals with Down syndrome does not fit well with these predictions. This leads to the third section of the paper, in which we consider key questions to be addressed in future research. We suggest that there are two questions to be answered, which follow directly from the contradictory results outlined in the previous section. These are 'What is the precise nature of the verbal short-term memory deficit in Down syndrome', and 'What are the consequences of this deficit for learning'. We discuss ways in which these questions might be addressed in future work.

Cue generation and memory construction in direct and generative autobiographical memory retrieval.

Science.gov (United States)

Harris, Celia B; O'Connor, Akira R; Sutton, John

2015-05-01

Theories of autobiographical memory emphasise effortful, generative search processes in memory retrieval. However recent research suggests that memories are often retrieved directly, without effortful search. We investigated whether direct and generative retrieval differed in the characteristics of memories recalled, or only in terms of retrieval latency. Participants recalled autobiographical memories in response to cue words. For each memory, they reported whether it was retrieved directly or generatively, rated its visuo-spatial perspective, and judged its accompanying recollective experience. Our results indicated that direct retrieval was commonly reported and was faster than generative retrieval, replicating recent findings. The characteristics of directly retrieved memories differed from generatively retrieved memories: directly retrieved memories had higher field perspective ratings and lower observer perspective ratings. However, retrieval mode did not influence recollective experience. We discuss our findings in terms of cue generation and content construction, and the implication for reconstructive models of autobiographical memory. Copyright © 2015 Elsevier Inc. All rights reserved.

Effect of W Contents on Martensitic Transformation and Shape Memory Effect in Co-Al-W Alloys

Science.gov (United States)

Yang, X.; Qian, B. N.; Peng, H. B.; Wu, B. J.; Wen, Y. H.

2018-04-01

To clarify the effect of W contents on the shape memory effect (SME) in the Co-Al alloys and its influencing mechanism, the SME, martensitic transformation, and deformation behavior were studied in the Co-7Al-xW ( x = 0, 4, 6, 9 wt pct) alloys. The results showed that the additions of W all deteriorated the SME in Co-7Al alloy when deformed at room temperature. However, when deformed in liquid nitrogen, the SME in Co-7Al alloy could be remarkably improved from 43 to 78 pct after the addition of 4 pct W, above which the SME decreased rapidly with the increase of W content although the yield strength of the parent phase rose due to the solution strengthening of W. The deterioration in SME induced by the excessive addition of W could be ascribed to its resulting significant drop of the start temperature of martensitic transformation.

Silent store detection and recording in memory storage

Energy Technology Data Exchange (ETDEWEB)

Bose, Pradip; Cher, Chen-Yong; Nair, Ravi

2017-03-14

An aspect includes receiving a write request that includes a memory address and write data. Stored data is read from a memory location at the memory address. Based on determining that the memory location was not previously modified, the stored data is compared to the write data. Based on the stored data matching the write data, the write request is completed without writing the write data to the memory and a corresponding silent store bit, in a silent store bitmap is set. Based on the stored data not matching the write data, the write data is written to the memory location, the silent store bit is reset and a corresponding modified bit is set. At least one of an application and an operating system is provided access to the silent store bitmap.

Silent store detection and recording in memory storage

Energy Technology Data Exchange (ETDEWEB)

Bose, Pradip; Cher, Chen-Yong; Nair, Ravi

2017-03-07

An aspect includes receiving a write request that includes a memory address and write data. Stored data is read from a memory location at the memory address. Based on determining that the memory location was not previously modified, the stored data is compared to the write data. Based on the stored data matching the write data, the write request is completed without writing the write data to the memory and a corresponding silent store bit, in a silent store bitmap is set. Based on the stored data not matching the write data, the write data is written to the memory location, the silent store bit is reset and a corresponding modified bit is set. At least one of an application and an operating system is provided access to the silent store bitmap.

Memory bottlenecks and memory contention in multi-core Monte Carlo transport codes

International Nuclear Information System (INIS)

Tramm, J.R.; Siegel, A.R.

2013-01-01

The simulation of whole nuclear cores through the use of Monte Carlo codes requires an impracticably long time-to-solution. We have extracted a kernel that executes only the most computationally expensive steps of the Monte Carlo particle transport algorithm - the calculation of macroscopic cross sections - in an effort to expose bottlenecks within multi-core, shared memory architectures. (authors)

Role of samarium additions on the shape memory behavior of iron based alloys

International Nuclear Information System (INIS)

Shakoor, R.A.; Khalid, F. Ahmad; Kang, Kisuk

2011-01-01

Research highlights: → The effect of samarium contents on shape memory behavior has been studied. → Addition of samarium increases the strength, c/a ratio and ε (hcp martensite). → Addition of samarium retards the nucleation of α (bcc martensite). → Improvement in shape memory effect with the increase in samarium contents. - Abstract: The effect of samarium contents on shape memory behavior of iron based shape memory alloys has been studied. It is found that the strength of the alloys increases with the increase in samarium contents. This effect can be attributed to the solid solution strengthening of austenite by samarium addition. It is also noticed that the shape memory effect increases with the increase in samarium contents. This improvement in shape memory effect presumably can be regarded as the effect of improvement in strength, increase in c/a ratio and obstruction of nucleation of α in the microstructure.

Bank switched memory interface for an image processor

International Nuclear Information System (INIS)

Barron, M.; Downward, J.

1980-09-01

A commercially available image processor is interfaced to a PDP-11/45 through an 8K window of memory addresses. When the image processor was not in use it was desired to be able to use the 8K address space as real memory. The standard method of accomplishing this would have been to use UNIBUS switches to switch in either the physical 8K bank of memory or the image processor memory. This method has the disadvantage of being rather expensive. As a simple alternative, a device was built to selectively enable or disable either an 8K bank of memory or the image processor memory. To enable the image processor under program control, GEN is contracted in size, the memory is disabled, a device partition for the image processor is created above GEN, and the image processor memory is enabled. The process is reversed to restore memory to GEN. The hardware to enable/disable the image and computer memories is controlled using spare bits from a DR-11K output register. The image processor and physical memory can be switched in or out on line with no adverse affects on the system's operation

False memories for aggressive acts.

Science.gov (United States)

Laney, Cara; Takarangi, Melanie K T

2013-06-01

Can people develop false memories for committing aggressive acts? How does this process compare to developing false memories for victimhood? In the current research we used a simple false feedback procedure to implant false memories for committing aggressive acts (causing a black eye or spreading malicious gossip) or for victimhood (receiving a black eye). We then compared these false memories to other subjects' true memories for equivalent events. False aggressive memories were all too easy to implant, particularly in the minds of individuals with a proclivity towards aggression. Once implanted, the false memories were indistinguishable from true memories for the same events, on several dimensions, including emotional content. Implications for aggression-related memory more generally as well as false confessions are discussed. Copyright © 2013 Elsevier B.V. All rights reserved.

The subjective content of historical memory in autobiographical narratives of representatives of titular ethnic group and national diaspora (based on the example of the Volga Germans

Directory of Open Access Journals (Sweden)

Rakhmatulina D.V.

2017-07-01

Full Text Available the article contains a justification of the research approach to the detection of subjective content of historical memory among groups of respondents from different ethnic background; presents the results of a study of two groups of respondents, who are descendants of the Volga Germans and the representatives of the titular nation (Russian; establishes the main cultural and historical events of life of the peoples that make up the historical memory.

Understanding women's experience of memory over the menopausal transition: subjective and objective memory in pre-, peri-, and postmenopausal women.

Science.gov (United States)

Unkenstein, Anne E; Bryant, Christina A; Judd, Fiona K; Ong, Ben; Kinsella, Glynda J

2016-12-01

Many women complain of forgetfulness during the menopausal transition. This study aimed to examine women's subjective perception of memory and their objective memory performance across the menopausal transition. One hundred thirty women, aged 40 to 60 years were recruited from outpatient Menopause and Gynaecological clinics at the Royal Women's Hospital, Melbourne. Women were divided into menopausal stage groups according to the Stages of Reproductive Aging Workshop criteria based on menstrual patterns. All women completed self-report measures of depressive, anxiety, vasomotor, and sleep symptoms; attitude to menopause; and various aspects of memory, including memory contentment, frequency of forgetting, sense of control over memory, and use of memory strategies. Women also completed a comprehensive neuropsychological evaluation assessing memory and executive function. Comprehensive neuropsychological assessment showed no difference between premenopausal (n = 36), perimenopausal (n = 54), and postmenopausal (n = 40) groups in performance on memory and executive tasks. Perimenopausal women, however, reported significantly more frequent forgetting (η = 0.09, P memory (η = 0.08, P memory. During the menopausal transition women with a more negative attitude to menopause and more intense depressive, anxiety, vasomotor, and sleep symptoms are more vulnerable to feeling less content with their memory.

Sensory memory consolidation observed: Increased specificity of detail over days

Science.gov (United States)

Weinberger, Norman M.; Miasnikov, Alexandre A.; Chen, Jemmy C.

2010-01-01

Memories are usually multidimensional, including contents such as sensory details, motivational state and emotional overtones. Memory contents generally change over time, most often reported as a loss in the specificity of detail. To study the temporal changes in the sensory contents of associative memory without motivational and emotional contents, we induced memory for acoustic frequency by pairing a tone with stimulation of the cholinergic nucleus basalis. Adult male rats were first tested for behavioral responses (disruption of ongoing respiration) to tones (1–15 kHz), yielding pre-training behavioral frequency generalization gradients (BFGG). They next received three days of training consisting of a conditioned stimulus (CS) tone (8.00 kHz, 70 dB, 2 s) either Paired (n = 5) or Unpaired (n = 5) with weak electrical stimulation (~48 μA) of the nucleus basalis (100 Hz, 0.2 s, co-terminating with CS offset). Testing for behavioral memory was performed by obtaining post-training BFGGs at two intervals, 24 and 96 h after training. At 24 h post-training, the Paired group exhibited associative behavioral memory manifested by significantly larger responses to tone than the Unpaired group. However, they exhibited no specificity in memory for the frequency of the tonal CS, as indexed by a flat BFGG. In contrast, after 96 h post-training the Paired group did exhibit specificity of memory as revealed by tuned BFGGs with a peak at the CS-band of frequencies. This increased detail of memory developed due to a loss of response to lower and higher frequency side-bands, without any change in the absolute magnitude of response to CS-band frequencies. These findings indicate that the sensory contents of associative memory can be revealed to become more specific, through temporal consolidation in the absence of non-sensory factors such as motivation and emotion. PMID:19038352

Sensory memory consolidation observed: increased specificity of detail over days.

Science.gov (United States)

Weinberger, Norman M; Miasnikov, Alexandre A; Chen, Jemmy C

2009-03-01

Memories are usually multidimensional, including contents such as sensory details, motivational state and emotional overtones. Memory contents generally change over time, most often reported as a loss in the specificity of detail. To study the temporal changes in the sensory contents of associative memory without motivational and emotional contents, we induced memory for acoustic frequency by pairing a tone with stimulation of the cholinergic nucleus basalis. Adult male rats were first tested for behavioral responses (disruption of ongoing respiration) to tones (1-15 kHz), yielding pre-training behavioral frequency generalization gradients (BFGG). They next received three days of training consisting of a conditioned stimulus (CS) tone (8.00 kHz, 70 dB, 2 s) either Paired (n=5) or Unpaired (n=5) with weak electrical stimulation (approximately 48 microA) of the nucleus basalis (100 Hz, 0.2 s, co-terminating with CS offset). Testing for behavioral memory was performed by obtaining post-training BFGGs at two intervals, 24 and 96 h after training. At 24 h post-training, the Paired group exhibited associative behavioral memory manifested by significantly larger responses to tone than the Unpaired group. However, they exhibited no specificity in memory for the frequency of the tonal CS, as indexed by a flat BFGG. In contrast, after 96 h post-training the Paired group did exhibit specificity of memory as revealed by tuned BFGGs with a peak at the CS-band of frequencies. This increased detail of memory developed due to a loss of response to lower and higher frequency side-bands, without any change in the absolute magnitude of response to CS-band frequencies. These findings indicate that the sensory contents of associative memory can be revealed to become more specific, through temporal consolidation in the absence of non-sensory factors such as motivation and emotion.

On the Power of Quantum Memory

OpenAIRE

Koenig, Robert; Maurer, Ueli; Renner, Renato

2003-01-01

We address the question whether quantum memory is more powerful than classical memory. In particular, we consider a setting where information about a random n-bit string X is stored in r classical or quantum bits, for r

Understanding Memory Loss | NIH MedlinePlus the Magazine

Science.gov (United States)

... of this page please turn Javascript on. Feature: Memory & Forgetfulness Understanding Memory Loss Past Issues / Summer 2013 Table of Contents ... weeks at a time. Some Treatable Causes of Memory Loss As we age, our bodies change, including ...

Insights on consciousness from taste memory research.

Science.gov (United States)

Gallo, Milagros

2016-01-01

Taste research in rodents supports the relevance of memory in order to determine the content of consciousness by modifying both taste perception and later action. Associated with this issue is the fact that taste and visual modalities share anatomical circuits traditionally related to conscious memory. This challenges the view of taste memory as a type of non-declarative unconscious memory.

Atomic memory access hardware implementations

Science.gov (United States)

Ahn, Jung Ho; Erez, Mattan; Dally, William J

2015-02-17

Atomic memory access requests are handled using a variety of systems and methods. According to one example method, a data-processing circuit having an address-request generator that issues requests to a common memory implements a method of processing the requests using a memory-access intervention circuit coupled between the generator and the common memory. The method identifies a current atomic-memory access request from a plurality of memory access requests. A data set is stored that corresponds to the current atomic-memory access request in a data storage circuit within the intervention circuit. It is determined whether the current atomic-memory access request corresponds to at least one previously-stored atomic-memory access request. In response to determining correspondence, the current request is implemented by retrieving data from the common memory. The data is modified in response to the current request and at least one other access request in the memory-access intervention circuit.

The Effects of Instruction on the Frequency and Characteristics of Involuntary Autobiographical Memories.

Science.gov (United States)

Barzykowski, Krystian; Niedźwieńska, Agnieszka

2016-01-01

The present study investigated the effects of experimental instruction on the retrieval of involuntary autobiographical memories (IAMs). In previous studies of IAMs, participants were either instructed to record only memories (henceforth, the restricted group) or any thoughts (henceforth, the unrestricted group). However, it is unknown whether these two different types of instructions influence the retrieval of IAMs. The most recent study by Vannucci and her colleagues directly addressed this question and demonstrated that the frequency and phenomenological characteristics of IAMs strongly depended on the type of instruction received. The goal of the present study was to replicate these results while addressing some limitations of the Vannucci et al. study and to test three possible mechanisms proposed to explain the effect of instructions on the retrieval of IAMs. Our results accord well with the data presented by Vannucci et al. When participants were instructed to record only IAMs (the restricted group), they reported more memories and rated them as being retrieved in a more goal-oriented fashion. Their memories also were less clear, vivid, detailed and were less frequently accompanied by physiological reactions, compared to memories reported by the participants in the unrestricted group. In addition, the events to which the memories referred were rated as more unusual and personal by the restricted group. These results are consistent with the assumption that retrieval of IAMs depends on the type of instructions used in a study. In addition, our results suggest that one of the main mechanisms underlying the higher frequency of IAMs in the restricted group may be participants' ability to monitor the stream of consciousness and to extract autobiographical content from this flow. Further implications of the effect of instructions for IAMs research are discussed.

The Effects of Instruction on the Frequency and Characteristics of Involuntary Autobiographical Memories.

Directory of Open Access Journals (Sweden)

Krystian Barzykowski

Full Text Available The present study investigated the effects of experimental instruction on the retrieval of involuntary autobiographical memories (IAMs. In previous studies of IAMs, participants were either instructed to record only memories (henceforth, the restricted group or any thoughts (henceforth, the unrestricted group. However, it is unknown whether these two different types of instructions influence the retrieval of IAMs. The most recent study by Vannucci and her colleagues directly addressed this question and demonstrated that the frequency and phenomenological characteristics of IAMs strongly depended on the type of instruction received. The goal of the present study was to replicate these results while addressing some limitations of the Vannucci et al. study and to test three possible mechanisms proposed to explain the effect of instructions on the retrieval of IAMs. Our results accord well with the data presented by Vannucci et al. When participants were instructed to record only IAMs (the restricted group, they reported more memories and rated them as being retrieved in a more goal-oriented fashion. Their memories also were less clear, vivid, detailed and were less frequently accompanied by physiological reactions, compared to memories reported by the participants in the unrestricted group. In addition, the events to which the memories referred were rated as more unusual and personal by the restricted group. These results are consistent with the assumption that retrieval of IAMs depends on the type of instructions used in a study. In addition, our results suggest that one of the main mechanisms underlying the higher frequency of IAMs in the restricted group may be participants' ability to monitor the stream of consciousness and to extract autobiographical content from this flow. Further implications of the effect of instructions for IAMs research are discussed.

The organization of Romanian social memory after the December 1989 events

Directory of Open Access Journals (Sweden)

Constantin-Ovidiu Craiu

2013-12-01

Full Text Available The social memory phenomenon causes debates nowadays, puts in opposition methodological schools, generates a series of incompatible theoretical positions. Proof that the concept of “social memory” “lived” its first age are the numerous research which regards the phenomenon, studies which led either to new theories of social memory (the theory of the organization of memory according to culture and interests is one of the acknowledged theories from which it starts in the development of the subject, or they certified the ones established until then. The present paper proposes as its objective to evaluate the factors which led to the readjustment of the social memory of the Romanian people after the events from 1989. I consider that the social memory can be organized under the influence of factors which acts unitary. As a result, I will analyze the connection between the political factor (decision – maker agents that can influence some contents of the collective memory and the social one (the public opinion of the group that undergoes major alterations regarding the contents of memory. I initiated the investigation approach from the observation that certain contents of the social memory resignify themselves through the direct influence of the social group, the power structure having the role of putting into practice the community’s “desire”. The necessity of a unitary co-operation between the community and the decision factor for the achievement of a new mnezic construction is imperative. For that purpose, I will analyze the effects of the non-unitary actions of these factors against the social memory, being known that not always the decision factor and the social factor (the community have the same attitudes towards certain mnesic contents. One can observe certain patterns concerning the organization of social memory in relation to these two factors, being analyzed the intentionality (what the two parts desire and the purpose (the

Multiple Types of Memory and Everyday Functional Assessment in Older Adults

Science.gov (United States)

Beaver, Jenna

2017-01-01

Abstract Objective Current proxy measures for assessing everyday functioning (e.g., questionnaires, performance-based measures, and direct observation) show discrepancies in their rating of functional status. The present study investigated the relationship between multiple proxy measures of functional status and content memory (i.e., memory for information), temporal order memory, and prospective memory in an older adult sample. Method A total of 197 community-dwelling older adults who did (n = 45) or did not meet (n = 152) criteria for mild cognitive impairment (MCI), completed six different assessments of functional status (two questionnaires, two performance-based tasks, and two direct observation tasks) as well as experimental measures of content memory, prospective memory, and temporal order memory. Results After controlling for demographics and content memory, the temporal order and prospective memory measures explained a significant amount of variance in all proxy functional status measures. When all variables were entered into the regression analyses, content memory and prospective memory were found to be significant predictors of all measures of functional status, whereas temporal order memory was a significant predictor for the questionnaire and direct observation measures, but not performance-based measures. Conclusion The results suggest that direct observation and questionnaire measures may be able to capture components of everyday functioning that require context and temporal sequencing abilities, such as multi-tasking, that are not as well captured in many current laboratory performance-based measures of functional status. Future research should aim to inform the development and use of maximally effective and valid proxy measures of functional ability. PMID:28334170

Emotional false memories in children with learning disabilities.

Science.gov (United States)

Mirandola, Chiara; Losito, Nunzia; Ghetti, Simona; Cornoldi, Cesare

2014-02-01

Research has shown that children with learning disabilities (LD) are less prone to evince associative illusions of memory as a result of impairments in their ability to engage in semantic processing. However, it is unclear whether this observation is true for scripted life events, especially if they include emotional content, or across a broad spectrum of learning disabilities. The present study addressed these issues by assessing recognition memory for script-like information in children with nonverbal learning disability (NLD), children with dyslexia, and typically developing children (N=51). Participants viewed photographs about 8 common events (e.g., family dinner), and embedded in each episode was either a negative or a neutral consequence of an unseen action. Children's memory was then tested on a yes/no recognition task that included old and new photographs. Results showed that the three groups performed similarly in recognizing target photographs, but exhibited differences in memory errors. Compared to other groups, children with NLD were more likely to falsely recognize photographs that depicted an unseen cause of an emotional seen event and associated more "Remember" responses to these errors. Children with dyslexia were equally likely to falsely recognize both unseen causes of seen photographs and photographs generally consistent with the script, whereas the other participant groups were more likely to falsely recognize unseen causes rather than script-consistent distractors. Results are interpreted in terms of mechanisms underlying false memories' formation in different clinical populations of children with LD. Copyright © 2013 Elsevier Ltd. All rights reserved.

Modulation of working memory updating: Does long-term memory lexical association matter?

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Artuso, Caterina; Palladino, Paola

2016-02-01

The aim of the present study was to investigate how working memory updating for verbal material is modulated by enduring properties of long-term memory. Two coexisting perspectives that account for the relation between long-term representation and short-term performance were addressed. First, evidence suggests that performance is more closely linked to lexical properties, that is, co-occurrences within the language. Conversely, other evidence suggests that performance is linked more to long-term representations which do not entail lexical/linguistic representations. Our aim was to investigate how these two kinds of long-term memory associations (i.e., lexical or nonlexical) modulate ongoing working memory activity. Therefore, we manipulated (between participants) the strength of the association in letters based on either frequency of co-occurrences (lexical) or contiguity along the sequence of the alphabet (nonlexical). Results showed a cost in working memory updating for strongly lexically associated stimuli only. Our findings advance knowledge of how lexical long-term memory associations between consonants affect working memory updating and, in turn, contribute to the study of factors which impact the updating process across memory systems.

MEMORY FOR POETRY: MORE THAN MEANING?

OpenAIRE

Atchley, Rachel M.; Hare, Mary L.

2013-01-01

The assumption has become that memory for words’ sound patterns, or form, is rapidly lost in comparison to content. Memory for form is also assumed to be verbatim rather than schematic. Oral story-telling traditions suggest otherwise. The present experiment investigated if form can be remembered schematically in spoken poetry, a context in which form is important. We also explored if sleep could help preserve memory for form. We tested whether alliterative sound patterns could cue memory for ...

Introduction to the special issue on visual working memory.

Science.gov (United States)

Wolfe, Jeremy M

2014-10-01

Visual working memory is a volatile, limited-capacity memory that appears to play an important role in our impression of a visual world that is continuous in time. It also mediates between the contents of the mind and the contents of that visual world. Research on visual working memory has become increasingly prominent in recent years. The articles in this special issue of Attention, Perception, & Psychophysics describe new empirical findings and theoretical understandings of the topic.

Working memory can enhance unconscious visual perception.

Science.gov (United States)

Pan, Yi; Cheng, Qiu-Ping; Luo, Qian-Ying

2012-06-01

We demonstrate that unconscious processing of a stimulus property can be enhanced when there is a match between the contents of working memory and the stimulus presented in the visual field. Participants first held a cue (a colored circle) in working memory and then searched for a brief masked target shape presented simultaneously with a distractor shape. When participants reported having no awareness of the target shape at all, search performance was more accurate in the valid condition, where the target matched the cue in color, than in the neutral condition, where the target mismatched the cue. This effect cannot be attributed to bottom-up perceptual priming from the presentation of a memory cue, because unconscious perception was not enhanced when the cue was merely perceptually identified but not actively held in working memory. These findings suggest that reentrant feedback from the contents of working memory modulates unconscious visual perception.

Working memory biasing of visual perception without awareness.

Science.gov (United States)

Pan, Yi; Lin, Bingyuan; Zhao, Yajun; Soto, David

2014-10-01

Previous research has demonstrated that the contents of visual working memory can bias visual processing in favor of matching stimuli in the scene. However, the extent to which such top-down, memory-driven biasing of visual perception is contingent on conscious awareness remains unknown. Here we showed that conscious awareness of critical visual cues is dispensable for working memory to bias perceptual selection mechanisms. Using the procedure of continuous flash suppression, we demonstrated that "unseen" visual stimuli during interocular suppression can gain preferential access to awareness if they match the contents of visual working memory. Strikingly, the very same effect occurred even when the visual cue to be held in memory was rendered nonconscious by masking. Control experiments ruled out the alternative accounts of repetition priming and different detection criteria. We conclude that working memory biases of visual perception can operate in the absence of conscious awareness.

Recent life stress exposure is associated with poorer long-term memory, working memory, and self-reported memory.

Science.gov (United States)

Shields, Grant S; Doty, Dominique; Shields, Rebecca H; Gower, Garrett; Slavich, George M; Yonelinas, Andrew P

2017-11-01

Although substantial research has examined the effects of stress on cognition, much of this research has focused on acute stress (e.g. manipulated in the laboratory) or chronic stress (e.g. persistent interpersonal or financial difficulties). In contrast, the effects of recent life stress on cognition have been relatively understudied. To address this issue, we examined how recent life stress is associated with long-term, working memory, and self-reported memory in a sample of 142 healthy young adults who were assessed at two time points over a two-week period. Recent life stress was measured using the newly-developed Stress and Adversity Inventory for Daily Stress (Daily STRAIN), which assesses the frequency of relatively common stressful life events and difficulties over the preceding two weeks. To assess memory performance, participants completed both long-term and working memory tasks. Participants also provided self-reports of memory problems. As hypothesized, greater recent life stress exposure was associated with worse performance on measures of long-term and working memory, as well as more self-reported memory problems. These associations were largely robust while controlling for possible confounds, including participants' age, sex, and negative affect. The findings indicate that recent life stress exposure is broadly associated with worse memory. Future studies should thus consider assessing recent life stress as a potential predictor, moderator, or covariate of memory performance.

Multiple Types of Memory and Everyday Functional Assessment in Older Adults.

Science.gov (United States)

Beaver, Jenna; Schmitter-Edgecombe, Maureen

2017-06-01

Current proxy measures for assessing everyday functioning (e.g., questionnaires, performance-based measures, and direct observation) show discrepancies in their rating of functional status. The present study investigated the relationship between multiple proxy measures of functional status and content memory (i.e., memory for information), temporal order memory, and prospective memory in an older adult sample. A total of 197 community-dwelling older adults who did (n = 45) or did not meet (n = 152) criteria for mild cognitive impairment (MCI), completed six different assessments of functional status (two questionnaires, two performance-based tasks, and two direct observation tasks) as well as experimental measures of content memory, prospective memory, and temporal order memory. After controlling for demographics and content memory, the temporal order and prospective memory measures explained a significant amount of variance in all proxy functional status measures. When all variables were entered into the regression analyses, content memory and prospective memory were found to be significant predictors of all measures of functional status, whereas temporal order memory was a significant predictor for the questionnaire and direct observation measures, but not performance-based measures. The results suggest that direct observation and questionnaire measures may be able to capture components of everyday functioning that require context and temporal sequencing abilities, such as multi-tasking, that are not as well captured in many current laboratory performance-based measures of functional status. Future research should aim to inform the development and use of maximally effective and valid proxy measures of functional ability. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Older adults report moderately more detailed autobiographical memories.

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Gardner, Robert S; Mainetti, Matteo; Ascoli, Giorgio A

2015-01-01

Autobiographical memory (AM) is an essential component of the human mind. Although the([A-z]+) amount and types of subjective detail (content) that compose AMs constitute important dimensions of recall, age-related changes in memory content are not well characterized. Previously, we introduced the Cue-Recalled Autobiographical Memory test (CRAM; see http://cramtest.info), an instrument that collects subjective reports of AM content, and applied it to college-aged subjects. CRAM elicits AMs using naturalistic word-cues. Subsequently, subjects date each cued AM to a life period and count the number of remembered details from specified categories (features), e.g., temporal detail, spatial detail, persons, objects, and emotions. The current work applies CRAM to a broad range of individuals (18-78 years old) to quantify the effects of age on AM content. Subject age showed a moderately positive effect on AM content: older compared with younger adults reported ∼16% more details (∼25 vs. ∼21 in typical AMs). This age-related increase in memory content was similarly observed for remote and recent AMs, although content declined with the age of the event among all subjects. In general, the distribution of details across features was largely consistent among younger and older adults. However, certain types of details, i.e., those related to objects and sequences of events, contributed more to the age effect on content. Altogether, this work identifies a moderate age-related feature-specific alteration in the way life events are subjectively recalled, among an otherwise stable retrieval profile.

Older adults report moderately more detailed autobiographical memories

Directory of Open Access Journals (Sweden)

Robert S Gardner

2015-05-01

Full Text Available Autobiographical memory (AM is an essential component of the human mind. Although the amount and types of subjective detail (content that compose AMs constitute important dimensions of recall, age-related changes in memory content are not well characterized. Previously, we introduced the Cue-Recalled Autobiographical Memory test (CRAM; see http://cramtest.info, an instrument that collects subjective reports of AM content, and applied it to college-aged subjects. CRAM elicits AMs using naturalistic word-cues. Subsequently, subjects date each cued AM to a life period and count the number of remembered details from specified categories (features, e.g., temporal detail, spatial detail, persons, objects, and emotions. The current work applies CRAM to a broad range of individuals (18-78 years old to quantify the effects of age on AM content. Subject age showed a moderately positive effect on AM content: older compared with younger adults reported ~16% more details (~25 vs. ~21 in typical AMs. This age-related increase in memory content was similarly observed for remote and recent AMs, although content declined with the age of the event among all subjects. In general, the distribution of details across features was largely consistent among younger and older adults. However, certain types of details, i.e., those related to objects and sequences of events, contributed more to the age effect on content. Altogether, this work identifies a moderate age-related feature-specific alteration in the way life events are subjectively recalled, among an otherwise stable retrieval profile.

What kind of memory has evolution wrought? Introductory article for the special issue of memory: adaptive memory: the emergence and nature of proximate mechanisms.

Science.gov (United States)

Otgaar, Henry; Howe, Mark L

2014-01-01

It is without question that our memory system evolved through a process of natural selection. However, basic research into the evolutionary foundations of memory has begun in earnest only recently. This is quite peculiar as the majority, perhaps even all, of memory research relates to whether memory is adaptive or not. In this Special Issue of Memory we have assembled a variety of papers that represent the cutting edge in research on the evolution of memory. These papers are centred on issues about the ultimate and proximate explanations of memory, the development of the adaptive functions of memory, as well as the positive consequences that arise from the current evolutionary form that our memory has taken. In this introductory article we briefly outline these different areas and indicate why they are vital for a more complete theory of memory. Further we argue that, by adopting a more applied stance in the area of the evolution of memory, one of the many future directions in this field could be a new branch of psychology that addresses questions in evolutionary legal psychology.

Influence of carbon content on the copper-telluride phase formation and on the resistive switching behavior of carbon alloyed Cu-Te conductive bridge random access memory cells

International Nuclear Information System (INIS)

Devulder, Wouter; De Schutter, Bob; Detavernier, Christophe; Opsomer, Karl; Franquet, Alexis; Meersschaut, Johan; Muller, Robert; Van Elshocht, Sven; Jurczak, Malgorzata; Goux, Ludovic; Belmonte, Attilio

2014-01-01

In this paper, we investigate the influence of the carbon content on the Cu-Te phase formation and on the resistive switching behavior in carbon alloyed Cu 0.6 Te 0.4 based conductive bridge random access memory (CBRAM) cells. Carbon alloying of copper-tellurium inhibits the crystallization, while attractive switching behavior is preserved when using the material as Cu-supply layer in CBRAM cells. The phase formation is first investigated in a combinatorial way. With increasing carbon content, an enlargement of the temperature window in which the material stays amorphous was observed. Moreover, if crystalline phases are formed, subsequent phase transformations are inhibited. The electrical switching behavior of memory cells with different carbon contents is then investigated by implementing them in 580 μm diameter dot TiN/Cu 0.6 Te 0.4 -C/Al 2 O 3 /Si memory cells. Reliable switching behavior is observed for carbon contents up to 40 at. %, with a resistive window of more than 2 orders of magnitude, whereas for 50 at. % carbon, a higher current in the off state and only a small resistive window are present after repeated cycling. This degradation can be ascribed to the higher thermal and lower drift contribution to the reset operation due to a lower Cu affinity towards the supply layer, leading cycle-after-cycle to an increasing amount of Cu in the switching layer, which contributes to the current. The thermal diffusion of Cu into Al 2 O 3 under annealing also gives an indication of the Cu affinity of the source layer. Time of flight secondary ion mass spectroscopy was used to investigate this migration depth in Al 2 O 3 before and after annealing, showing a higher Cu, Te, and C migration for high carbon contents

Influence of carbon content on the copper-telluride phase formation and on the resistive switching behavior of carbon alloyed Cu-Te conductive bridge random access memory cells

Science.gov (United States)

Devulder, Wouter; Opsomer, Karl; Franquet, Alexis; Meersschaut, Johan; Belmonte, Attilio; Muller, Robert; De Schutter, Bob; Van Elshocht, Sven; Jurczak, Malgorzata; Goux, Ludovic; Detavernier, Christophe

2014-02-01

In this paper, we investigate the influence of the carbon content on the Cu-Te phase formation and on the resistive switching behavior in carbon alloyed Cu0.6Te0.4 based conductive bridge random access memory (CBRAM) cells. Carbon alloying of copper-tellurium inhibits the crystallization, while attractive switching behavior is preserved when using the material as Cu-supply layer in CBRAM cells. The phase formation is first investigated in a combinatorial way. With increasing carbon content, an enlargement of the temperature window in which the material stays amorphous was observed. Moreover, if crystalline phases are formed, subsequent phase transformations are inhibited. The electrical switching behavior of memory cells with different carbon contents is then investigated by implementing them in 580 μm diameter dot TiN/Cu0.6Te0.4-C/Al2O3/Si memory cells. Reliable switching behavior is observed for carbon contents up to 40 at. %, with a resistive window of more than 2 orders of magnitude, whereas for 50 at. % carbon, a higher current in the off state and only a small resistive window are present after repeated cycling. This degradation can be ascribed to the higher thermal and lower drift contribution to the reset operation due to a lower Cu affinity towards the supply layer, leading cycle-after-cycle to an increasing amount of Cu in the switching layer, which contributes to the current. The thermal diffusion of Cu into Al2O3 under annealing also gives an indication of the Cu affinity of the source layer. Time of flight secondary ion mass spectroscopy was used to investigate this migration depth in Al2O3 before and after annealing, showing a higher Cu, Te, and C migration for high carbon contents.

DNA methylation and memory formation.

Science.gov (United States)

Day, Jeremy J; Sweatt, J David

2010-11-01

Memory formation and storage require long-lasting changes in memory-related neuronal circuits. Recent evidence indicates that DNA methylation may serve as a contributing mechanism in memory formation and storage. These emerging findings suggest a role for an epigenetic mechanism in learning and long-term memory maintenance and raise apparent conundrums and questions. For example, it is unclear how DNA methylation might be reversed during the formation of a memory, how changes in DNA methylation alter neuronal function to promote memory formation, and how DNA methylation patterns differ between neuronal structures to enable both consolidation and storage of memories. Here we evaluate the existing evidence supporting a role for DNA methylation in memory, discuss how DNA methylation may affect genetic and neuronal function to contribute to behavior, propose several future directions for the emerging subfield of neuroepigenetics, and begin to address some of the broader implications of this work.

Dissociating Measures of Consciousness from Measures of Short-Term Memory

DEFF Research Database (Denmark)

Sørensen, Thomas Alrik; Ásgeirsson, Árni Gunnar; Staugaard, Camilla Funch

Often, the contents of consciousness are equated with the contents of short-term memory (or working memory), sometimes to a point where they are treated as identical entities. In the present study we aimed to investigate whether they may be modulated independently and thus dissociated from each...... if conscious content simply can be reduced to a cognitive process like short-term memory. In two experiments, we combined two different measures of short-term memory capacity to investigate how manipulations of set-size affect performance in observers with the Perceptual Awareness Scale (PAS) to measure...... conscious experience of the stimulus in every trial (Ramsøy & Overgaard, 2004; Overgaard & Sørensen, 2004). We trained observers to report their experience of a visual target stimulus on the four-point PAS scale; ranging from “no experience” to “clear experience”. To measure short-term memory we used...

Memory and Its Effect on Adult Function

Directory of Open Access Journals (Sweden)

Shokouh Navvabi-Nejad

2000-07-01

Full Text Available Memory capabilities, including its mechanisms and memory approaches weaken as age increases. However, the studies reveal that the content of memory, i.e. the knowledge stored in it, usually increases. Memory system includes sensory memory within which environmental information are recorded. Short-term memory is related to storing data at awareness level, whereas long-term memory is associated with  storing knowledge and past experiences. Psychological and physiological factors such as mental and physical health, nutrition, using narcotic substances and alcohol, and also stimulation during life may affect all functions of the elderly such as their memory. Unfortunately, many researchers overlooked the effects of these variables on subjects.

VOP memory management in MPEG-4

Science.gov (United States)

Vaithianathan, Karthikeyan; Panchanathan, Sethuraman

2001-03-01

MPEG-4 is a multimedia standard that requires Video Object Planes (VOPs). Generation of VOPs for any kind of video sequence is still a challenging problem that largely remains unsolved. Nevertheless, if this problem is treated by imposing certain constraints, solutions for specific application domains can be found. MPEG-4 applications in mobile devices is one such domain where the opposite goals namely low power and high throughput are required to be met. Efficient memory management plays a major role in reducing the power consumption. Specifically, efficient memory management for VOPs is difficult because the lifetimes of these objects vary and these life times may be overlapping. Varying life times of the objects requires dynamic memory management where memory fragmentation is a key problem that needs to be addressed. In general, memory management systems address this problem by following a combination of strategy, policy and mechanism. For MPEG4 based mobile devices that lack instruction processors, a hardware based memory management solution is necessary. In MPEG4 based mobile devices that have a RISC processor, using a Real time operating system (RTOS) for this memory management task is not expected to be efficient because the strategies and policies used by the ROTS is often tuned for handling memory segments of smaller sizes compared to object sizes. Hence, a memory management scheme specifically tuned for VOPs is important. In this paper, different strategies, policies and mechanisms for memory management are considered and an efficient combination is proposed for the case of VOP memory management along with a hardware architecture, which can handle the proposed combination.

Perceptual salience affects the contents of working memory during free-recollection of objects from natural scenes

Directory of Open Access Journals (Sweden)

Tiziana ePedale

2015-02-01

Full Text Available One of the most important issues in the study of cognition is to understand which are the factors determining internal representation of the external world. Previous literature has started to highlight the impact of low-level sensory features (indexed by saliency-maps in driving attention selection, hence increasing the probability for objects presented in complex and natural scenes to be successfully encoded into working memory(WM and then correctly remembered. Here we asked whether the probability of retrieving high-saliency objects modulates the overall contents of WM, by decreasing the probability of retrieving other, lower-saliency objects. We presented pictures of natural scenes for 4 secs. After a retention period of 8 secs, we asked participants to verbally report as many objects/details as possible of the previous scenes. We then computed how many times the objects located at either the peak of maximal or minimal saliency in the scene (as indexed by a saliency-map; Itti et al., 1998 were recollected by participants. Results showed that maximal-saliency objects were recollected more often and earlier in the stream of successfully reported items than minimal-saliency objects. This indicates that bottom-up sensory salience increases the recollection probability and facilitates the access to memory representation at retrieval, respectively. Moreover, recollection of the maximal- (but not the minimal- saliency objects predicted the overall amount of successfully recollected objects: The higher the probability of having successfully reported the most-salient object in the scene, the lower the amount of recollected objects. These findings highlight that bottom-up sensory saliency modulates the current contents of WM during recollection of objects from natural scenes, most likely by reducing available resources to encode and then retrieve other (lower saliency objects.

Destination memory and cognitive theory of mind in normal ageing.

Science.gov (United States)

El Haj, Mohamad; Raffard, Stéphane; Gély-Nargeot, Marie-Christine

2016-01-01

Destination memory is the ability to remember the destination to which a piece of information has been addressed (e.g., "Did I tell you about the promotion?"). This ability is found to be impaired in normal ageing. Our work aimed to link this deterioration to the decline in theory of mind. Forty younger adults (M age = 23.13 years, SD = 4.00) and 36 older adults (M age = 69.53 years, SD = 8.93) performed a destination memory task. They also performed the False-belief test addressing cognitive theory of mind and the Reading the mind in the eyes test addressing affective theory of mind. Results showed significant deterioration in destination memory, cognitive theory of mind and affective theory of mind in the older adults. The older adults' performance on destination memory was significantly correlated with and predicted by their performance on cognitive theory of mind. Difficulties in the ability to interpret and predict others' mental states are related to destination memory decline in older adults.

Absolute symbolic addressing, a structure making time-sharing easier

International Nuclear Information System (INIS)

Debraine, P.

1968-08-01

Time-sharing of computers asks for a certain number of conditions, particularly, an efficient dynamic loading of programs and data. This paper indicates a paging method making linkages with a minimum of table-looking operations. The principle is to use associative memory registers for calling blocks of physical memory, the block address being given by the concatenation of a file number (located in a base register) and a page number (located in the instruction proper). The position within the block is given by a displacement located in the instruction. A second associated base register contains the local part (page number + displacement) of the base address. This extended base register system allows executing programs in a very large programming complex without loss of time. The addresses are fixed at assembly time and the blocks can be loaded anywhere without modification for execution. The various problems associated with the execution of complex programs are presented in this context and shown to be easily solved by the proposed system, the realization of which would be very easy starting from the computer structures existing now. (author) [fr

Patient learning of treatment contents in cognitive therapy.

Science.gov (United States)

Gumport, Nicole B; Dong, Lu; Lee, Jason Y; Harvey, Allison G

2018-03-01

Research has demonstrated that both memory and learning for treatment contents are poor, and that both are associated with worse treatment outcome. The Memory Support Intervention has been shown to improve memory for treatment, but it has not yet been established if this intervention can also improve learning of treatment contents. This study was designed to document the number of times participants exhibited each of the indices of learning, to examine the indices of learning and their relationship to recall of treatment points, and to investigate the association between the indices of learning and depression outcome. Adults diagnosed with major depressive disorder (N = 48) were randomly assigned to 14 sessions of cognitive therapy-as-usual (CT-as-usual) or cognitive therapy plus the Memory Support Intervention (CT + Memory Support). Measures of learning, memory, and depressive symptomatology were taken at mid-treatment, post-treatment, and at 6-month follow-up. Relative to the CT-as-usual group, participants in the CT + Memory Support group reported more accurate thoughts and applications of treatment points at mid-treatment, post-treatment, and 6-month follow-up. Patient recall was significantly correlated with application and cognitive generalization. Thoughts and application at mid-treatment were associated with increased odds of treatment response at post-treatment. The learning measure for this study has not yet been psychometrically validated. The results are based on a small sample. Learning during treatment is poor, but modifiable via the Memory Support Intervention. These results provide encouraging data that improving learning of treatment contents can reduce symptoms during and following treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Dreaming and offline memory consolidation.

Science.gov (United States)

Wamsley, Erin J

2014-03-01

Converging evidence suggests that dreaming is influenced by the consolidation of memory during sleep. Following encoding, recently formed memory traces are gradually stabilized and reorganized into a more permanent form of long-term storage. Sleep provides an optimal neurophysiological state to facilitate this process, allowing memory networks to be repeatedly reactivated in the absence of new sensory input. The process of memory reactivation and consolidation in the sleeping brain appears to influence conscious experience during sleep, contributing to dream content recalled on awakening. This article outlines several lines of evidence in support of this hypothesis, and responds to some common objections.

Learning and memory and its relationship with the lateralization of epileptic focus in subjects with temporal lobe epilepsy

Directory of Open Access Journals (Sweden)

Daniel Fuentes

2014-04-01

Full Text Available Background : In medial temporal lobe epilepsy (MTLE, previous studies addressing the hemispheric laterality of epileptogenic focus and its relationship with learning and memory processes have reported controversial findings. Objective : To compare the performance of MTLE patients according to the location of the epileptogenic focus on the left (MTLEL or right temporal lobe (MTLER on tasks of episodic learning and memory for verbal and visual content. Methods : One hundred patients with MTLEL and one hundred patients with MTLER were tested with the following tasks: the Rey Auditory Verbal Learning Test (RAVLT and the Logical Memory-WMS-R to evaluate verbal learning and memory; and the Rey Visual Design Learning Test (RVDLT and the Visual Reproduction-WMS-R to evaluate visual learning and memory. Results : The MTLEL sample showed significantly worse performance on the RAVLT (p < 0.005 and on the Logical Memory tests (p < 0.01 than MTLER subjects. However, there were no significant between-group differences in regard to the visual memory tests. Discussion : Our findings suggest that verbal learning and memory abilities are dependent on the structural and functional integrity of the left temporal lobe, while visual abilities are less dependent on the right temporal lobe.

Reversible Inactivation of the Higher Order Auditory Cortex during Fear Memory Consolidation Prevents Memory-Related Activity in the Basolateral Amygdala during Remote Memory Retrieval.

Science.gov (United States)

Cambiaghi, Marco; Renna, Annamaria; Milano, Luisella; Sacchetti, Benedetto

2017-01-01

Recent findings have shown that the auditory cortex, and specifically the higher order Te2 area, is necessary for the consolidation of long-term fearful memories and that it interacts with the amygdala during the retrieval of long-term fearful memories. Here, we tested whether the reversible blockade of Te2 during memory consolidation may affect the activity changes occurring in the amygdala during the retrieval of fearful memories. To address this issue, we blocked Te2 in a reversible manner during memory consolidation processes. After 4 weeks, we assessed the activity of Te2 and individual nuclei of the amygdala during the retrieval of long-term memories. Rats in which Te2 was inactivated upon memory encoding showed a decreased freezing and failed to show Te2-to-basolateral amygdala (BLA) synchrony during memory retrieval. In addition, the expression of the immediate early gene zif268 in the lateral, basal and central amygdala nuclei did not show memory-related enhancement. As all sites were intact upon memory retrieval, we propose that the auditory cortex represents a key node in the consolidation of fear memories and it is essential for amygdala nuclei to support memory retrieval process.

Models of Working Memory

National Research Council Canada - National Science Library

Miyake, Akira

1997-01-01

.... Understanding the mechanisms and structures underlying working memory is, hence, one of the most important scientific issues that need to be addressed to improve the efficiency and performance...

Homodyne detection of holographic memory systems

Science.gov (United States)

Urness, Adam C.; Wilson, William L.; Ayres, Mark R.

2014-09-01

We present a homodyne detection system implemented for a page-wise holographic memory architecture. Homodyne detection by holographic memory systems enables phase quadrature multiplexing (doubling address space), and lower exposure times (increasing read transfer rates). It also enables phase modulation, which improves signal-to-noise ratio (SNR) to further increase data capacity. We believe this is the first experimental demonstration of homodyne detection for a page-wise holographic memory system suitable for a commercial design.

A Memory-based Robot Architecture based on Contextual Information

OpenAIRE

Pratama, Ferdian; Mastrogiovanni, Fulvio; Chong, Nak Young

2014-01-01

In this paper, we present a preliminary conceptual design for a robot long-term memory architecture based on the notion of context. Contextual information is used to organize the data flow between Working Memory (including Perceptual Memory) and Long-Term Memory components. We discuss the major influence of the notion of context within Episodic Memory on Semantic and Procedural Memory, respectively. We address how the occurrence of specific object-related events in time impacts on the semanti...

Visual memory, the long and the short of it: A review of visual working memory and long-term memory.

Science.gov (United States)

Schurgin, Mark W

2018-04-23

The majority of research on visual memory has taken a compartmentalized approach, focusing exclusively on memory over shorter or longer durations, that is, visual working memory (VWM) or visual episodic long-term memory (VLTM), respectively. This tutorial provides a review spanning the two areas, with readers in mind who may only be familiar with one or the other. The review is divided into six sections. It starts by distinguishing VWM and VLTM from one another, in terms of how they are generally defined and their relative functions. This is followed by a review of the major theories and methods guiding VLTM and VWM research. The final section is devoted toward identifying points of overlap and distinction across the two literatures to provide a synthesis that will inform future research in both fields. By more intimately relating methods and theories from VWM and VLTM to one another, new advances can be made that may shed light on the kinds of representational content and structure supporting human visual memory.

Impulse: Memory System Support for Scientific Applications

Directory of Open Access Journals (Sweden)

John B. Carter

1999-01-01

Full Text Available Impulse is a new memory system architecture that adds two important features to a traditional memory controller. First, Impulse supports application‐specific optimizations through configurable physical address remapping. By remapping physical addresses, applications control how their data is accessed and cached, improving their cache and bus utilization. Second, Impulse supports prefetching at the memory controller, which can hide much of the latency of DRAM accesses. Because it requires no modification to processor, cache, or bus designs, Impulse can be adopted in conventional systems. In this paper we describe the design of the Impulse architecture, and show how an Impulse memory system can improve the performance of memory‐bound scientific applications. For instance, Impulse decreases the running time of the NAS conjugate gradient benchmark by 67%. We expect that Impulse will also benefit regularly strided, memory‐bound applications of commercial importance, such as database and multimedia programs.

The nature of forgetting from short-term memory

OpenAIRE

Muter, Paul

2001-01-01

Memory and forgetting are inextricably intertwined. Any account of short-term memory (STM) should address the following question: If three, four, or five chunks are being held in STM, what happens after attention is diverted?

Self-imagining enhances recognition memory in memory-impaired individuals with neurological damage.

Science.gov (United States)

Grilli, Matthew D; Glisky, Elizabeth L

2010-11-01

The ability to imagine an elaborative event from a personal perspective relies on several cognitive processes that may potentially enhance subsequent memory for the event, including visual imagery, semantic elaboration, emotional processing, and self-referential processing. In an effort to find a novel strategy for enhancing memory in memory-impaired individuals with neurological damage, we investigated the mnemonic benefit of a method we refer to as self-imagining-the imagining of an event from a realistic, personal perspective. Fourteen individuals with neurologically based memory deficits and 14 healthy control participants intentionally encoded neutral and emotional sentences under three instructions: structural-baseline processing, semantic processing, and self-imagining. Findings revealed a robust "self-imagination effect (SIE)," as self-imagination enhanced recognition memory relative to deep semantic elaboration in both memory-impaired individuals, F(1, 13) = 32.11, p memory disorder nor were they related to self-reported vividness of visual imagery, semantic processing, or emotional content of the materials. The findings suggest that the SIE may depend on unique mnemonic mechanisms possibly related to self-referential processing and that imagining an event from a personal perspective makes that event particularly memorable even for those individuals with severe memory deficits. Self-imagining may thus provide an effective rehabilitation strategy for individuals with memory impairment.

Locating the self in autobiographical memories

DEFF Research Database (Denmark)

Antalikova, Radka; de la Mata, Manuel; Santamaría, Andrés

2016-01-01

Systematic cross-cultural variation in autobiographical memory has been demonstrated in previous research. This variation has been interpreted as mirroring differences in culturally diverging self-conceptions, implying that content characteristics of autobiographical memories can be used...... to capture how the self is present, and presented, in autobiographical memory in a more nuanced way than done in previous research. Hence, the system could be applicable for use in studies with a variety of culturally diverse populations....

Elements of episodic-like memory in animals.

Science.gov (United States)

Clayton, N S; Griffiths, D P; Emery, N J; Dickinson, A

2001-09-29

A number of psychologists have suggested that episodic memory is a uniquely human phenomenon and, until recently, there was little evidence that animals could recall a unique past experience and respond appropriately. Experiments on food-caching memory in scrub jays question this assumption. On the basis of a single caching episode, scrub jays can remember when and where they cached a variety of foods that differ in the rate at which they degrade, in a way that is inexplicable by relative familiarity. They can update their memory of the contents of a cache depending on whether or not they have emptied the cache site, and can also remember where another bird has hidden caches, suggesting that they encode rich representations of the caching event. They make temporal generalizations about when perishable items should degrade and also remember the relative time since caching when the same food is cached in distinct sites at different times. These results show that jays form integrated memories for the location, content and time of caching. This memory capability fulfils Tulving's behavioural criteria for episodic memory and is thus termed 'episodic-like'. We suggest that several features of episodic memory may not be unique to humans.

Paging memory from random access memory to backing storage in a parallel computer

Science.gov (United States)

Archer, Charles J; Blocksome, Michael A; Inglett, Todd A; Ratterman, Joseph D; Smith, Brian E

2013-05-21

Paging memory from random access memory (`RAM`) to backing storage in a parallel computer that includes a plurality of compute nodes, including: executing a data processing application on a virtual machine operating system in a virtual machine on a first compute node; providing, by a second compute node, backing storage for the contents of RAM on the first compute node; and swapping, by the virtual machine operating system in the virtual machine on the first compute node, a page of memory from RAM on the first compute node to the backing storage on the second compute node.

Exploring self-defining memories in schizophrenia.

Science.gov (United States)

Raffard, Stéphane; D'Argembeau, Arnaud; Lardi, Claudia; Bayard, Sophie; Boulenger, Jean-Philippe; Van Der Linden, Martial

2009-01-01

Previous studies have shown that patients with schizophrenia are impaired in recalling specific events from their personal past. However, the relationship between autobiographical memory impairments and disturbance of the sense of identity in schizophrenia has not been investigated in detail. In this study the authors investigated schizophrenic patients' ability to recall self-defining memories; that is, memories that play an important role in building and maintaining the self-concept. Results showed that patients recalled as many specific self-defining memories as healthy participants. However, patients with schizophrenia exhibited an abnormal reminiscence bump and reported different types of thematic content (i.e., they recalled less memories about past achievements and more memories regarding hospitalisation and stigmatisation of illness). Furthermore, the findings suggest that impairments in extracting meaning from personal memories could represent a core disturbance of autobiographical memory in patients with schizophrenia.

Are There Multiple Kinds of Episodic Memory? An fMRI Investigation Comparing Autobiographical and Recognition Memory Tasks.

Science.gov (United States)

Chen, Hung-Yu; Gilmore, Adrian W; Nelson, Steven M; McDermott, Kathleen B

2017-03-08

What brain regions underlie retrieval from episodic memory? The bulk of research addressing this question with fMRI has relied upon recognition memory for materials encoded within the laboratory. Another, less dominant tradition has used autobiographical methods, whereby people recall events from their lifetime, often after being cued with words or pictures. The current study addresses how the neural substrates of successful memory retrieval differed as a function of the targeted memory when the experimental parameters were held constant in the two conditions (except for instructions). Human participants studied a set of scenes and then took two types of memory test while undergoing fMRI scanning. In one condition (the picture memory test), participants reported for each scene (32 studied, 64 nonstudied) whether it was recollected from the prior study episode. In a second condition (the life memory test), participants reported for each scene (32 studied, 64 nonstudied) whether it reminded them of a specific event from their preexperimental lifetime. An examination of successful retrieval (yes responses) for recently studied scenes for the two test types revealed pronounced differences; that is, autobiographical retrieval instantiated with the life memory test preferentially activated the default mode network, whereas hits in the picture memory test preferentially engaged the parietal memory network as well as portions of the frontoparietal control network. When experimental cueing parameters are held constant, the neural underpinnings of successful memory retrieval differ when remembering life events and recently learned events. SIGNIFICANCE STATEMENT Episodic memory is often discussed as a solitary construct. However, experimental traditions examining episodic memory use very different approaches, and these are rarely compared to one another. When the neural correlates associated with each approach have been directly contrasted, results have varied considerably

Searching for serial refreshing in working memory: Using response times to track the content of the focus of attention over time.

Science.gov (United States)

Vergauwe, Evie; Hardman, Kyle O; Rouder, Jeffrey N; Roemer, Emily; McAllaster, Sara; Cowan, Nelson

2016-12-01

One popular idea is that, to support the maintenance of a set of elements over brief periods of time, the focus of attention rotates among the different elements, thereby serially refreshing the content of working memory (WM). In the research reported here, probe letters were presented between to-be-remembered letters, and response times to these probes were used to infer the status of the different items in WM. If the focus of attention cycles from one item to the next, its content should be different at different points in time, and this should be reflected in a change in the response time patterns over time. Across a set of four experiments, we demonstrated a striking pattern of invariance in the response time patterns over time, suggesting either that the content of the focus of attention did not change over time or that response times cannot be used to infer the content of the focus of attention. We discuss how this pattern constrains models of WM, attention, and human information processing.

Music-based memory enhancement in Alzheimer's disease: promise and limitations.

Science.gov (United States)

Simmons-Stern, Nicholas R; Deason, Rebecca G; Brandler, Brian J; Frustace, Bruno S; O'Connor, Maureen K; Ally, Brandon A; Budson, Andrew E

2012-12-01

In a previous study (Simmons-Stern, Budson & Ally, 2010), we found that patients with Alzheimer's disease (AD) better recognized visually presented lyrics when the lyrics were also sung rather than spoken at encoding. The present study sought to further investigate the effects of music on memory in patients with AD by making the content of the song lyrics relevant for the daily life of an older adult and by examining how musical encoding alters several different aspects of episodic memory. Patients with AD and healthy older adults studied visually presented novel song lyrics related to instrumental activities of daily living (IADL) that were accompanied by either a sung or a spoken recording. Overall, participants performed better on a memory test of general lyric content for lyrics that were studied sung as compared to spoken. However, on a memory test of specific lyric content, participants performed equally well for sung and spoken lyrics. We interpret these results in terms of a dual-process model of recognition memory such that the general content questions represent a familiarity-based representation that is preferentially sensitive to enhancement via music, while the specific content questions represent a recollection-based representation unaided by musical encoding. Additionally, in a test of basic recognition memory for the audio stimuli, patients with AD demonstrated equal discrimination for sung and spoken stimuli. We propose that the perceptual distinctiveness of musical stimuli enhanced metamemorial awareness in AD patients via a non-selective distinctiveness heuristic, thereby reducing false recognition while at the same time reducing true recognition and eliminating the mnemonic benefit of music. These results are discussed in the context of potential music-based memory enhancement interventions for the care of patients with AD. Published by Elsevier Ltd.

Hardware Compilation of Application-Specific Memory-Access Interconnect

DEFF Research Database (Denmark)

Venkataramani, Girish; Bjerregaard, Tobias; Chelcea, Tiberiu

2006-01-01

operations dependent on memory reads. More fundamental is that dependences between accesses may not be statically provable (e.g., if the specification language permits pointers), which introduces memory-consistency problems. Addressing these issues with static scheduling results in overly conservative...... enables specifications to include arbitrary memory references (e.g., pointers) and allows the memory system to incorporate features that might cause the latency of a memory access to vary dynamically. This results in raising the level of abstraction in the input specification, enabling faster design times...

Deciphering Neural Codes of Memory during Sleep

Science.gov (United States)

Chen, Zhe; Wilson, Matthew A.

2017-01-01

Memories of experiences are stored in the cerebral cortex. Sleep is critical for consolidating hippocampal memory of wake experiences into the neocortex. Understanding representations of neural codes of hippocampal-neocortical networks during sleep would reveal important circuit mechanisms on memory consolidation, and provide novel insights into memory and dreams. Although sleep-associated ensemble spike activity has been investigated, identifying the content of memory in sleep remains challenging. Here, we revisit important experimental findings on sleep-associated memory (i.e., neural activity patterns in sleep that reflect memory processing) and review computational approaches for analyzing sleep-associated neural codes (SANC). We focus on two analysis paradigms for sleep-associated memory, and propose a new unsupervised learning framework (“memory first, meaning later”) for unbiased assessment of SANC. PMID:28390699

Recognition of simple visual images using a sparse distributed memory: Some implementations and experiments

Science.gov (United States)

Jaeckel, Louis A.

1990-01-01

Previously, a method was described of representing a class of simple visual images so that they could be used with a Sparse Distributed Memory (SDM). Herein, two possible implementations are described of a SDM, for which these images, suitably encoded, will serve both as addresses to the memory and as data to be stored in the memory. A key feature of both implementations is that a pattern that is represented as an unordered set with a variable number of members can be used as an address to the memory. In the 1st model, an image is encoded as a 9072 bit string to be used as a read or write address; the bit string may also be used as data to be stored in the memory. Another representation, in which an image is encoded as a 256 bit string, may be used with either model as data to be stored in the memory, but not as an address. In the 2nd model, an image is not represented as a vector of fixed length to be used as an address. Instead, a rule is given for determining which memory locations are to be activated in response to an encoded image. This activation rule treats the pieces of an image as an unordered set. With this model, the memory can be simulated, based on a method of computing the approximate result of a read operation.

The Gorani Wedding Ritual – Between Individual and Collective Memory

Directory of Open Access Journals (Sweden)

Jadranka Đorđević Crnobrnja

2014-11-01

Full Text Available In this paper I will attempt to determine which contents are present in individual memories of weddings and underline the contents which contribute to the formation of commonplace memories within personal memories. By studying individual personal memories of a ritual practice, I will attempt to answer questions about the relationship between individual and collective memory. In the paper I will also consider the issue of the influence of individual memories on the construction of ethnic identity. The paper is based on an analysis of narrative discourse which has been adapted for ethnographic research. The Gorani wedding ritual represents a social practice which encompasses not only the influence of collective on personal remembrance and memory, but also the reverse. The Gorani wedding ritual is an example of a social holiday which, on a personal level creates a feeling of connection between individuals and their community, while on a collective level it creates conditions for the continuity of the Gorani community.

Control over interfering memories in eating disorders.

Science.gov (United States)

Stramaccia, Davide Francesco; Penolazzi, Barbara; Libardi, Arianna; Genovese, Aldo; Castelli, Luigi; Palomba, Daniela; Galfano, Giovanni

2018-02-01

Recent studies have suggested that patients suffering from either anorexia nervosa (AN) or bulimia nervosa (BN) exhibit abnormal performance in the ability to control cognitive interference in response selection. We assessed the status of cognitive control in episodic memory by addressing the ability to inhibit interfering memories. To this end, we used the retrieval-practice paradigm, which allows for measuring both the beneficial and the detrimental effects of memory practice. The latter phenomenon, known as retrieval-induced forgetting (RIF), is thought to reflect an adaptive inhibitory mechanism aimed at reducing competition in memory retrieval. Twenty-seven healthy controls and 27 patients suffering from eating disorders (either AN or BN) performed a retrieval-practice paradigm and a control task addressing general reactivity and filled a self-report questionnaire on impulsivity. No differences between patients and healthy controls were observed for the beneficial effects of practice. The same pattern also emerged for RIF. However, when patients with AN and BN were analyzed separately, a clear dissociation emerged: patients with AN displayed no hint of RIF, whereas patients with BN showed an intact memory suppression performance. No group differences emerged in the control task. Our findings suggest a specific impairment in the ability to suppress interfering memories in patients with AN, thus extending current evidence of cognitive control deficits in AN to episodic memory.

Scientific developments of liquid crystal-based optical memory: a review

Science.gov (United States)

Prakash, Jai; Chandran, Achu; Biradar, Ashok M.

2017-01-01

The memory behavior in liquid crystals (LCs), although rarely observed, has made very significant headway over the past three decades since their discovery in nematic type LCs. It has gone from a mere scientific curiosity to application in variety of commodities. The memory element formed by numerous LCs have been protected by patents, and some commercialized, and used as compensation to non-volatile memory devices, and as memory in personal computers and digital cameras. They also have the low cost, large area, high speed, and high density memory needed for advanced computers and digital electronics. Short and long duration memory behavior for industrial applications have been obtained from several LC materials, and an LC memory with interesting features and applications has been demonstrated using numerous LCs. However, considerable challenges still exist in searching for highly efficient, stable, and long-lifespan materials and methods so that the development of useful memory devices is possible. This review focuses on the scientific and technological approach of fascinating applications of LC-based memory. We address the introduction, development status, novel design and engineering principles, and parameters of LC memory. We also address how the amalgamation of LCs could bring significant change/improvement in memory effects in the emerging field of nanotechnology, and the application of LC memory as the active component for futuristic and interesting memory devices.

A review of visual memory capacity: Beyond individual items and towards structured representations

Science.gov (United States)

Brady, Timothy F.; Konkle, Talia; Alvarez, George A.

2012-01-01

Traditional memory research has focused on identifying separate memory systems and exploring different stages of memory processing. This approach has been valuable for establishing a taxonomy of memory systems and characterizing their function, but has been less informative about the nature of stored memory representations. Recent research on visual memory has shifted towards a representation-based emphasis, focusing on the contents of memory, and attempting to determine the format and structure of remembered information. The main thesis of this review will be that one cannot fully understand memory systems or memory processes without also determining the nature of memory representations. Nowhere is this connection more obvious than in research that attempts to measure the capacity of visual memory. We will review research on the capacity of visual working memory and visual long-term memory, highlighting recent work that emphasizes the contents of memory. This focus impacts not only how we estimate the capacity of the system - going beyond quantifying how many items can be remembered, and moving towards structured representations - but how we model memory systems and memory processes. PMID:21617025

The Mind and Brain of Short-Term Memory

OpenAIRE

Jonides, John; Lewis, Richard L.; Nee, Derek Evan; Lustig, Cindy A.; Berman, Marc G.; Moore, Katherine Sledge

2008-01-01

The past 10 years have brought near-revolutionary changes in psychological theories about short-term memory, with similarly great advances in the neurosciences. Here, we critically examine the major psychological theories (the “mind”) of short-term memory and how they relate to evidence about underlying brain mechanisms. We focus on three features that must be addressed by any satisfactory theory of short-term memory. First, we examine the evidence for the architecture of short-term memory, w...

Can we throw information out of visual working memory and does this leave informational residue in long-term memory?

Directory of Open Access Journals (Sweden)

Ashleigh Monette Maxcey

2014-04-01

Full Text Available Can we entirely erase a temporary memory representation from mind? This question has been addressed in several recent studies that tested the specific hypothesis that a representation can be erased from visual working memory based on a cue that indicated that the representation was no longer necessary for the task. In addition to behavioral results that are consistent with the idea that we can throw information out of visual working memory, recent neurophysiological recordings support this proposal. However, given the infinite capacity of long-term memory, it is unclear whether throwing a representation out of visual working memory really removes its effects on memory entirely. In this paper we advocate for an approach that examines our ability to erase memory representations from working memory, as well as possible traces that those erased representations leave in long-term memory.

The content of cigarette counter-advertising: are perceived functions of smoking addressed?

Science.gov (United States)

Rhodes, Nancy; Roskos-Ewoldsen, David; Eno, Cassie A; Monahan, Jennifer L

2009-01-01

Media campaigns can be an effective tool in reducing adolescent smoking. To better understand the types of ads that have been used in campaigns in the United States, a content analysis was conducted of ads available at the U.S. Centers for Disease Control and Prevention (CDC) Media Campaign Resource Center (MCRC; Waves 1 through 7). A total of 487 ads were coded. Ads were coded for target audience, primary theme present in the ad, and sensation value-production techniques that have been demonstrated to attract attention and increase arousal. Primary themes extended earlier studies by focusing on the perceived functions of smoking (weight lose, stress management, controlling negative affect) as well as the traditional themes of industry attack, the health consequences of smoking, secondhand smoke, quitting, and the social image of smokers. A majority of ads were rated as having moderate sensation value, and ads targeted at teens and children were, on the average, higher in sensation value than those targeting general audiences. Changes across time suggest that campaigns are focusing more on adolescent smoking and relying more on attacking the tobacco industry. Research indicates that the functions of stress relief, mood regulation, and weight loss are strong reasons for initiating and continuing to smoke cigarettes; however, none of the 487 ads addressed these functional themes. Implications for developing campaigns that more closely relate to the functions of smoking are discussed.

Auditory short-term memory behaves like visual short-term memory.

Directory of Open Access Journals (Sweden)

Kristina M Visscher

2007-03-01

Full Text Available Are the information processing steps that support short-term sensory memory common to all the senses? Systematic, psychophysical comparison requires identical experimental paradigms and comparable stimuli, which can be challenging to obtain across modalities. Participants performed a recognition memory task with auditory and visual stimuli that were comparable in complexity and in their neural representations at early stages of cortical processing. The visual stimuli were static and moving Gaussian-windowed, oriented, sinusoidal gratings (Gabor patches; the auditory stimuli were broadband sounds whose frequency content varied sinusoidally over time (moving ripples. Parallel effects on recognition memory were seen for number of items to be remembered, retention interval, and serial position. Further, regardless of modality, predicting an item's recognizability requires taking account of (1 the probe's similarity to the remembered list items (summed similarity, and (2 the similarity between the items in memory (inter-item homogeneity. A model incorporating both these factors gives a good fit to recognition memory data for auditory as well as visual stimuli. In addition, we present the first demonstration of the orthogonality of summed similarity and inter-item homogeneity effects. These data imply that auditory and visual representations undergo very similar transformations while they are encoded and retrieved from memory.

Auditory short-term memory behaves like visual short-term memory.

Science.gov (United States)

Visscher, Kristina M; Kaplan, Elina; Kahana, Michael J; Sekuler, Robert

2007-03-01

Are the information processing steps that support short-term sensory memory common to all the senses? Systematic, psychophysical comparison requires identical experimental paradigms and comparable stimuli, which can be challenging to obtain across modalities. Participants performed a recognition memory task with auditory and visual stimuli that were comparable in complexity and in their neural representations at early stages of cortical processing. The visual stimuli were static and moving Gaussian-windowed, oriented, sinusoidal gratings (Gabor patches); the auditory stimuli were broadband sounds whose frequency content varied sinusoidally over time (moving ripples). Parallel effects on recognition memory were seen for number of items to be remembered, retention interval, and serial position. Further, regardless of modality, predicting an item's recognizability requires taking account of (1) the probe's similarity to the remembered list items (summed similarity), and (2) the similarity between the items in memory (inter-item homogeneity). A model incorporating both these factors gives a good fit to recognition memory data for auditory as well as visual stimuli. In addition, we present the first demonstration of the orthogonality of summed similarity and inter-item homogeneity effects. These data imply that auditory and visual representations undergo very similar transformations while they are encoded and retrieved from memory.

The Relation Between Goals and Autobiographical Memory

DEFF Research Database (Denmark)

Johannessen, Kim Berg; Rasmussen, Anne Scharling; Berntsen, Dorthe

facilitate recall of goal congruent autobiographical memories which supports the idea of autobiographical memory facilitating goal attainment. Further, no differences between involuntary and voluntary memories with regard to frequency or characteristics of goal related content were found. Yet memories...... related to goals were rated as more central to the person's identity, life story and expectations for the future than non-goal related memories, irrespective of mode of recall. Interestingly, depression and PTSD symptoms correlated positively with the proportion of goal related memories, thereby......The present study examines involuntary (spontaneously retrieved) versus voluntary (deliberately retrieved) autobiographical memories in relation to earlier registered goals measured by the Personal Concern Inventory (Cox & Klinger, 2000). We found that the important and not yet planned goals...

Memory for conversation and the development of common ground.

Science.gov (United States)

McKinley, Geoffrey L; Brown-Schmidt, Sarah; Benjamin, Aaron S

2017-11-01

Efficient conversation is guided by the mutual knowledge, or common ground, that interlocutors form as a conversation progresses. Characterized from the perspective of commonly used measures of memory, efficient conversation should be closely associated with item memory-what was said-and context memory-who said what to whom. However, few studies have explicitly probed memory to evaluate what type of information is maintained following a communicative exchange. The current study examined how item and context memory relate to the development of common ground over the course of a conversation, and how these forms of memory vary as a function of one's role in a conversation as speaker or listener. The process of developing common ground was positively related to both item and context memory. In addition, content that was spoken was remembered better than content that was heard. Our findings illustrate how memory assessments can complement language measures by revealing the impact that basic conversational processes have on memory for what has been discussed. By taking this approach, we show that not only does the process of forming common ground facilitate communication in the present, but it also promotes an enduring record of that event, facilitating conversation into the future.

Command vector memory systems: high performance at low cost

OpenAIRE

Corbal San Adrián, Jesús; Espasa Sans, Roger; Valero Cortés, Mateo

1998-01-01

The focus of this paper is on designing both a low cost and high performance, high bandwidth vector memory system that takes advantage of modern commodity SDRAM memory chips. To successfully extract the full bandwidth from SDRAM parts, we propose a new memory system organization based on sending commands to the memory system as opposed to sending individual addresses. A command specifies, in a few bytes, a request for multiple independent memory words. A command is similar to a burst found in...

Hardware support for collecting performance counters directly to memory

Science.gov (United States)

Gara, Alan; Salapura, Valentina; Wisniewski, Robert W.

2012-09-25

Hardware support for collecting performance counters directly to memory, in one aspect, may include a plurality of performance counters operable to collect one or more counts of one or more selected activities. A first storage element may be operable to store an address of a memory location. A second storage element may be operable to store a value indicating whether the hardware should begin copying. A state machine may be operable to detect the value in the second storage element and trigger hardware copying of data in selected one or more of the plurality of performance counters to the memory location whose address is stored in the first storage element.

Human memory research: Current hypotheses and new perspectives

Directory of Open Access Journals (Sweden)

Antônio Jaeger

Full Text Available Abstract Research on human memory has increased significantly in the last few decades. Inconsistencies and controversies inherent to such research, however, are rarely articulated on published reports. The goal of the present article is to present and discuss a series of open questions related to major topics on human memory research that can be addressed by future research. The topics covered here are visual working memory, recognition memory, emotion and memory interaction, and methodological issues of false memories studies. Overall, the present work reveals a series of open questions and alternative analysis which could be useful for the process of hypothesis generation, and consequently for the design and implementation of future research on human memory.

Is memory for music special?

Science.gov (United States)

Schulkind, Matthew D

2009-07-01

Although psychologists since Hermann Ebbinghaus have studied memory, research in this area has focused on visual and verbal stimuli with little attention paid to music. This bias is surprising because of the ubiquity of music in human cultures across history as well as current cultural beliefs that memory for music is "special." This paper examines the question of whether memory for music is special by addressing two related questions: First, do cultural beliefs about the mnemonic power of music stand up to empirical test? Second, can theories designed to explain memory for non-musical stimuli be applied to musical stimuli? A review of the literature suggests that music is special in some circumstances but not others and that some theories designed to explain cognitive processing of linguistic stimuli apply reasonably well to musical stimuli. Thus, although the question of whether memory for music is special remains open, the unique structure of musical stimuli strongly suggests that memory for music is indeed special.

Memory and Self–Neuroscientific Landscapes

Science.gov (United States)

Markowitsch, Hans J.

2013-01-01

Relations between memory and the self are framed from a number of perspectives—developmental aspects, forms of memory, interrelations between memory and the brain, and interactions between the environment and memory. The self is seen as dividable into more rudimentary and more advanced aspects. Special emphasis is laid on memory systems and within them on episodic autobiographical memory which is seen as a pure human form of memory that is dependent on a proper ontogenetic development and shaped by the social environment, including culture. Self and episodic autobiographical memory are seen as interlocked in their development and later manifestation. Aside from content-based aspects of memory, time-based aspects are seen along two lines—the division between short-term and long-term memory and anterograde—future-oriented—and retrograde—past-oriented memory. The state dependency of episodic autobiographical is stressed and implications of it—for example, with respect to the occurrence of false memories and forensic aspects—are outlined. For the brain level, structural networks for encoding, consolidation, storage, and retrieval are discussed both by referring to patient data and to data obtained in normal participants with functional brain imaging methods. It is elaborated why descriptions from patients with functional or dissociative amnesia are particularly apt to demonstrate the facets in which memory, self, and personal temporality are interwoven. PMID:24967303

Transactive memory in organizational groups: the effects of content, consensus, specialization, and accuracy on group performance.

Science.gov (United States)

Austin, John R

2003-10-01

Previous research on transactive memory has found a positive relationship between transactive memory system development and group performance in single project laboratory and ad hoc groups. Closely related research on shared mental models and expertise recognition supports these findings. In this study, the author examined the relationship between transactive memory systems and performance in mature, continuing groups. A group's transactive memory system, measured as a combination of knowledge stock, knowledge specialization, transactive memory consensus, and transactive memory accuracy, is positively related to group goal performance, external group evaluations, and internal group evaluations. The positive relationship with group performance was found to hold for both task and external relationship transactive memory systems.

Does content affect whether users remember that Web pages were hyperlinked?

Science.gov (United States)

Jones, Keith S; Ballew, Timothy V; Probst, C Adam

2008-10-01

We determined whether memory for hyperlinks improved when they represented relations between the contents of the Web pages. J. S. Farris (2003) found that memory for hyperlinks improved when they represented relations between the contents of the Web pages. However, Farris's (2003) participants could have used their knowledge of site content to answer questions about relations that were instantiated via the site's content and its hyperlinks. In Experiment 1, users navigated a Web site and then answered questions about relations that were instantiated only via content, only via hyperlinks, and via content and hyperlinks. Unlike Farris (2003), we split the latter into two sets. One asked whether certain content elements were related, and the other asked whether certain Web pages were hyperlinked. Experiment 2 replicated Experiment 1 with one modification: The questions that were asked about relations instantiated via content and hyperlinks were changed so that each question's wrong answer was also related to the question's target. Memory for hyperlinks improved when they represented relations instantiated within the content of the Web pages. This was true when (a) questions about content and hyperlinks were separated (Experiment 1) and (b) each question's wrong answer was also related to the question's target (Experiment 2). The accuracy of users' mental representations of local architecture depended on whether hyperlinks were related to the site's content. Designers who want users to remember hyperlinks should associate those hyperlinks with content that reflects the relation between the contents on the Web pages.

Characterization of music-evoked autobiographical memories.

Science.gov (United States)

Janata, Petr; Tomic, Stefan T; Rakowski, Sonja K

2007-11-01

Despite music's prominence in Western society and its importance to individuals in their daily lives, very little is known about the memories and emotions that are often evoked when hearing a piece of music from one's past. We examined the content of music-evoked autobiographical memories (MEAMs) using a novel approach for selecting stimuli from a large corpus of popular music, in both laboratory and online settings. A set of questionnaires probed the cognitive and affective properties of the evoked memories. On average, 30% of the song presentations evoked autobiographical memories, and the majority of songs also evoked various emotions, primarily positive, that were felt strongly. The third most common emotion was nostalgia. Analyses of written memory reports found both general and specific levels of autobiographical knowledge to be represented, and several social and situational contexts for memory formation were common across many memories. The findings indicate that excerpts of popular music serve as potent stimuli for studying the structure of autobiographical memories.

Individual differences in preschoolers' emotion content memory: the role of emotion knowledge.

Science.gov (United States)

Channell, Marie Moore; Barth, Joan M

2013-07-01

This study examined the relation between preschool children's emotion knowledge and their ability to recall emotionally salient information. In total, 42 participants (ages 35-65months) viewed a brief video in which a child played with different toys and expressed one of four basic emotions (happy, sad, angry, or afraid) or a neutral expression in each of 10 vignettes. Children were tested on memory accuracy from the vignettes, and their emotion knowledge was also measured. Results indicated that preschoolers' emotion knowledge was significantly related to memory accuracy for emotion information above and beyond the effect of age or receptive language skills. Tests of a mediation model revealed that emotion knowledge fully mediated the effect of age (or general developmental level) on memory accuracy. Copyright © 2013 Elsevier Inc. All rights reserved.

Music-Based Memory Enhancement in Alzheimer’s Disease: Promise and Limitations

Science.gov (United States)

Simmons-Stern, Nicholas R.; Deason, Rebecca G.; Brandler, Brian J.; Frustace, Bruno S.; O’Connor, Maureen K.; Ally, Brandon A.; Budson, Andrew E.

2012-01-01

In a previous study (Simmons-Stern, Budson, & Ally 2010), we found that patients with Alzheimer’s disease (AD) better recognized visually presented lyrics when the lyrics were also sung rather than spoken at encoding. The present study sought to further investigate the effects of music on memory in patients with AD by making the content of the song lyrics relevant for the daily life of an older adult and by examining how musical encoding alters several different aspects of episodic memory. Patients with AD and healthy older adults studied visually presented novel song lyrics related to instrumental activities of daily living (IADL) that were accompanied by either a sung or a spoken recording. Overall, participants performed better on a memory test of general lyric content for lyrics that were studied sung as compared to spoken. However, on a memory test of specific lyric content, participants performed equally well for sung and spoken lyrics. We interpret these results in terms of a dual-process model of recognition memory such that the general content questions represent a familiarity-based representation that is preferentially sensitive to enhancement via music, while the specific content questions represent a recollection-based representation unaided by musical encoding. Additionally, in a test of basic recognition memory for the audio stimuli, patients with AD demonstrated equal discrimination for sung and spoken stimuli. We propose that the perceptual distinctiveness of musical stimuli enhanced metamemorial awareness in AD patients via a non-selective distinctiveness heuristic, thereby reducing false recognition while at the same time reducing true recognition and eliminating the mnemonic benefit of music. These results are discussed in the context of potential music-based memory enhancement interventions for the care of patients with AD. PMID:23000133

Students' Long-Term Memories from an Ecology Field Excursion: Retelling a Narrative as an Interplay between Implicit and Explicit Memories

Science.gov (United States)

Stolpe, Karin; Bjorklund, Lars

2013-01-01

This study aims to investigate the science content remembered by biology students 6 and 12 months after an ecology excursion. The students' memories were tested during a stimulated recall interview. The authors identified three different types of memories: "recall," "recognition" and "narratives." The "dual…

Defense.gov Special Report: Memorial Day 2012

Science.gov (United States)

information so we can address your issue or question. United States Department of Defense United States Veterans Past, Present on Memorial Day Obama: Memorial Day Honors the Fallen 'Flags In' Tradition Honors Blog: Everyone Can Find A Way to Honor our Service Members Over the past few years, I have been blessed

[Distribution of neural memory, loading factor, its regulation and optimization].

Science.gov (United States)

Radchenko, A N

1999-01-01

Recording and retrieving functions of the neural memory are simulated as a control of local conformational processes in neural synaptic fields. The localization of conformational changes is related to the afferent temporal-spatial pulse pattern flow, the microstructure of connections and a plurality of temporal delays in synaptic fields and afferent pathways. The loci of conformations are described by sets of afferent addresses named address domains. Being superimposed on each other, address domains form a multilayer covering of the address space of the neuron or the ensemble. The superposition factor determines the dissemination of the conformational process, and the fuzzing of memory, and its accuracy and reliability. The engram is formed as detects in the packing of the address space and hence can be retrieved in inverse form. The accuracy of the retrieved information depends on the threshold level of conformational transitions, the distribution of conformational changes in synaptic fields of the neuronal population, and the memory loading factor. The latter is represented in the model by a slow potential. It reflects total conformational changes and displaces the membrane potential to monostable conformational regimes, by governing the exit from the recording regime, the potentiation of the neurone, and the readiness to reproduction. A relative amplitude of the slow potential and the coefficient of postconformational modification of ionic conductivity, which provides maximum reliability, accuracy, and capacity of memory, are calculated.

A new Variable Resolution Associative Memory for High Energy Physics

CERN Document Server

Annovi, A; The ATLAS collaboration; Beretta, M; Bossini, E; Crescioli, F; Dell'Orso, M; Giannetti, P; Hoff, J; Liberali, V; Liu, T; Magalotti, D; Piendibene, M; Sacco, A; Schoening, A; Soltveit, H K; Stabile, A; Tripiccione, R; Vitillo, R; Volpi, G

2011-01-01

We describe an important advancement for the Associative Memory device (AM). The AM is a VLSI processor for pattern recognition based on Content Addressable Memory (CAM) architecture. The AM is optimized for on-line track finding in high-energy physics experiments. Pattern matching is carried out finding track candidates in coarse resolution “roads”. A large AM bank stores all trajectories of interest, called “patterns”, for a given detector resolution. The AM extracts roads compatible with a given event during detector read-out. Two important variables characterize the quality of the AM bank: its “coverage” and the level of “found fakes”. The coverage, which describes the geometric efficiency of a bank, is defined as the fraction of tracks that match at least a pattern in the bank. Given a certain road size, the coverage of the bank can be increased just adding patterns to the bank, while the number of found fakes unfortunately is roughly proportional to this number of patterns in the bank. M...

Hippocampal activation during retrieval of spatial context from episodic and semantic memory.

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Hoscheidt, Siobhan M; Nadel, Lynn; Payne, Jessica; Ryan, Lee

2010-10-15

The hippocampus, a region implicated in the processing of spatial information and episodic memory, is central to the debate concerning the relationship between episodic and semantic memory. Studies of medial temporal lobe amnesic patients provide evidence that the hippocampus is critical for the retrieval of episodic but not semantic memory. On the other hand, recent neuroimaging studies of intact individuals report hippocampal activation during retrieval of both autobiographical memories and semantic information that includes historical facts, famous faces, and categorical information, suggesting that episodic and semantic memory may engage the hippocampus during memory retrieval in similar ways. Few studies have matched episodic and semantic tasks for the degree to which they include spatial content, even though spatial content may be what drives hippocampal activation during semantic retrieval. To examine this issue, we conducted a functional magnetic resonance imaging (fMRI) study in which retrieval of spatial and nonspatial information was compared during an episodic and semantic recognition task. Results show that the hippocampus (1) participates preferentially in the retrieval of episodic memories; (2) is also engaged by retrieval of semantic memories, particularly those that include spatial information. These data suggest that sharp dissociations between episodic and semantic memory may be overly simplistic and that the hippocampus plays a role in the retrieval of spatial content whether drawn from a memory of one's own life experiences or real-world semantic knowledge. Published by Elsevier B.V.

Functional memory metals

International Nuclear Information System (INIS)

Dunne, D.P.

2000-01-01

The field of shape memory phenomena in metals and alloys has developed in a sporadic fashion from a scientific curiosity to a vigorously growing niche industry, over a period close to a full working lifetime. Memory metal research and development is replete with scientist and engineer 'true believers', who can finally feel content that their longstanding confidence in the potential of these unusual functional materials has not been misplaced. This paper reviews the current range of medical and non-medical systems and devices which are based on memory metals and attempts to predict trends in applications over the next decade. The market is dominated by Ni Ti alloys which have proved to exhibit the best and most reproducible properties for application in a wide range of medical and non-medical devices

Shape Memory Polymers Containing Higher Acrylate Content Display Increased Endothelial Cell Attachment

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Govindarajan, Tina; Shandas, Robin

2018-01-01

Shape Memory Polymers (SMPs) are smart materials that can recall their shape upon the application of a stimulus, which makes them appealing materials for a variety of applications, especially in biomedical devices. Most prior SMP research has focused on tuning bulk properties; studying surface effects of SMPs may extend the use of these materials to blood-contacting applications, such as cardiovascular stents, where surfaces that support rapid endothelialization have been correlated to stent success. Here, we evaluate endothelial attachment onto the surfaces of a family of SMPs previously developed in our group that have shown promise for biomedical devices. Nine SMP formulations containing varying amounts of tert-Butyl acrylate (tBA) and Poly(ethylene glycol) dimethacrylate (PEGDMA) were analyzed for endothelial cell attachment. Dynamic mechanical analysis (DMA), contact angle studies, and atomic force microscopy (AFM) were used to verify bulk and surface properties of the SMPs. Human umbilical vein endothelial cell (HUVEC) attachment and viability was verified using fluorescent methods. Endothelial cells preferentially attached to SMPs with higher tBA content, which have rougher, more hydrophobic surfaces. HUVECs also displayed an increased metabolic activity on these high tBA SMPs over the course of the study. This class of SMPs may be promising candidates for next generation blood-contacting devices. PMID:29707382

Shape Memory Polymers Containing Higher Acrylate Content Display Increased Endothelial Cell Attachment

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Tina Govindarajan

2017-11-01

Full Text Available Shape Memory Polymers (SMPs are smart materials that can recall their shape upon the application of a stimulus, which makes them appealing materials for a variety of applications, especially in biomedical devices. Most prior SMP research has focused on tuning bulk properties; studying surface effects of SMPs may extend the use of these materials to blood-contacting applications, such as cardiovascular stents, where surfaces that support rapid endothelialization have been correlated to stent success. Here, we evaluate endothelial attachment onto the surfaces of a family of SMPs previously developed in our group that have shown promise for biomedical devices. Nine SMP formulations containing varying amounts of tert-Butyl acrylate (tBA and Poly(ethylene glycol dimethacrylate (PEGDMA were analyzed for endothelial cell attachment. Dynamic mechanical analysis (DMA, contact angle studies, and atomic force microscopy (AFM were used to verify bulk and surface properties of the SMPs. Human umbilical vein endothelial cell (HUVEC attachment and viability was verified using fluorescent methods. Endothelial cells preferentially attached to SMPs with higher tBA content, which have rougher, more hydrophobic surfaces. HUVECs also displayed an increased metabolic activity on these high tBA SMPs over the course of the study. This class of SMPs may be promising candidates for next generation blood-contacting devices.

Test data generation for LRU cache-memory testing

OpenAIRE

Evgeni, Kornikhin

2009-01-01

System functional testing of microprocessors deals with many assembly programs of given behavior. The paper proposes new constraint-based algorithm of initial cache-memory contents generation for given behavior of assembly program (with cache misses and hits). Although algorithm works for any types of cache-memory, the paper describes algorithm in detail for basis types of cache-memory only: fully associative cache and direct mapped cache.

Visual working memory contaminates perception.

Science.gov (United States)

Kang, Min-Suk; Hong, Sang Wook; Blake, Randolph; Woodman, Geoffrey F

2011-10-01

Indirect evidence suggests that the contents of visual working memory may be maintained within sensory areas early in the visual hierarchy. We tested this possibility using a well-studied motion repulsion phenomenon in which perception of one direction of motion is distorted when another direction of motion is viewed simultaneously. We found that observers misperceived the actual direction of motion of a single motion stimulus if, while viewing that stimulus, they were holding a different motion direction in visual working memory. Control experiments showed that none of a variety of alternative explanations could account for this repulsion effect induced by working memory. Our findings provide compelling evidence that visual working memory representations directly interact with the same neural mechanisms as those involved in processing basic sensory events.

Can we throw information out of visual working memory and does this leave informational residue in long-term memory?

OpenAIRE

Ashleigh Monette Maxcey; Geoffrey F. Woodman

2014-01-01

Can we entirely erase a temporary memory representation from mind? This question has been addressed in several recent studies that tested the specific hypothesis that a representation can be erased from visual working memory based on a cue that indicated that the representation was no longer necessary for the task. In addition to behavioral results that are consistent with the idea that we can throw information out of visual working memory, recent neurophysiological recordings support this pr...

Emotionally negative pictures enhance gist memory.

Science.gov (United States)

Bookbinder, S H; Brainerd, C J

2017-02-01

In prior work on how true and false memory are influenced by emotion, valence and arousal have often been conflated. Thus, it is difficult to say which specific effects are caused by valence and which are caused by arousal. In the present research, we used a picture-memory paradigm that allowed emotional valence to be manipulated with arousal held constant. Negatively valenced pictures elevated both true and false memory, relative to positive and neutral pictures. Conjoint recognition modeling revealed that negative valence (a) reduced erroneous suppression of true memories and (b) increased the familiarity of the semantic content of both true and false memories. Overall, negative valence impaired the verbatim side of episodic memory but enhanced the gist side, and these effects persisted even after a week-long delay. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

[Episodic autobiographical memory in depression: a review].

Science.gov (United States)

Lemogne, C; Piolino, P; Jouvent, R; Allilaire, J-F; Fossati, P

2006-10-01

avoidance of intrusive memories; 3) quite stable over time, ie, remaining after remission; and 4) related to short-term prognosis in depression. Although it is not clear whether overgenerality is a cause or an effect of depression, there is some evidence to suggest that overgenerality is a trait marker indicating vulnerability to persistent depression. Mood-congruent effect, a well-known effect in depression, has been addressed in both autobio-graphical and non-autobiographical memory. Depressed patients spontaneously recall more negative than positive memories. With the AMT, depressed patients take longer to respond to positive than to negative cues, whereas controls do the opposite. Depression is also associated with a high occurrence of spontaneous intrusive memories of stressful life events. Studies found intrusions and related avoidance, as measured by the Impact of Event Scale, to be positively correlated with overgenerality, whereas there was no direct link between performance on the Autobiographical Memory Test and stressful life events per se. Both Williams' mnemonic interlock model and Conway's self-memory system are useful models to address the complexity of findings regarding autobiographical memory and depression. According to Williams, repeated avoidance of stressful memories leads depressed patients to have an autobiographical memory functioning characterized by iterative retrievals of categorical overgeneral memories, producing an enduring overgeneral retrieval style. According to Conway, the recollection of autobiographical memories requires a retrieval process that provides access to sensory/perceptual event-specific knowledge (ie perceptions and feelings) via a personal semantic knowledge base (ie lifetime periods and generic events). This retrieval process (generative retrieval mode) relies on both executive functioning and current self-view, namely the working-self. Spontaneous memories, usually vivid, result from a direct retrieval mode in which event

Recognition Decisions from Visual Working Memory Are Mediated by Continuous Latent Strengths

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Ricker, Timothy J.; Thiele, Jonathan E.; Swagman, April R.; Rouder, Jeffrey N.

2017-01-01

Making recognition decisions often requires us to reference the contents of working memory, the information available for ongoing cognitive processing. As such, understanding how recognition decisions are made when based on the contents of working memory is of critical importance. In this work we examine whether recognition decisions based on the…

Negative Emotional Arousal Impairs Associative Memory Performance for Emotionally Neutral Content in Healthy Participants.

Directory of Open Access Journals (Sweden)

Jonathan Guez

Full Text Available The effect of emotional arousal on memory presents a complex pattern with previous studies reporting conflicting results of both improved and reduced memory performance following arousal manipulations. In this study we further tested the effect of negative emotional arousal (NEA on individual-item recognition and associative recognition of neutral stimuli in healthy participants, and hypothesized that NEA will particularly impair associative memory performance. The current study consists of two experiments; in both, participants studied a list of word-pairs and were then tested for items (items recognition test, and for associations (associative recognition test. In the first experiment, the arousal manipulation was induced by flashing emotionally-negative or neutral pictures between study-pairs while in the second experiment arousal was induced by presenting emotionally-negative or neutral pictures between lists. The results of the two experiments converged and supported an associative memory deficit observed under NEA conditions. We suggest that NEA is associated with an altered ability to bind one stimulus to another as a result of impaired recollection, resulting in poorer associative memory performance. The current study findings may contribute to the understanding of the mechanism underlying memory impairments reported in disorders associated with traumatic stress.

Spike-timing theory of working memory.

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Botond Szatmáry

Full Text Available Working memory (WM is the part of the brain's memory system that provides temporary storage and manipulation of information necessary for cognition. Although WM has limited capacity at any given time, it has vast memory content in the sense that it acts on the brain's nearly infinite repertoire of lifetime long-term memories. Using simulations, we show that large memory content and WM functionality emerge spontaneously if we take the spike-timing nature of neuronal processing into account. Here, memories are represented by extensively overlapping groups of neurons that exhibit stereotypical time-locked spatiotemporal spike-timing patterns, called polychronous patterns; and synapses forming such polychronous neuronal groups (PNGs are subject to associative synaptic plasticity in the form of both long-term and short-term spike-timing dependent plasticity. While long-term potentiation is essential in PNG formation, we show how short-term plasticity can temporarily strengthen the synapses of selected PNGs and lead to an increase in the spontaneous reactivation rate of these PNGs. This increased reactivation rate, consistent with in vivo recordings during WM tasks, results in high interspike interval variability and irregular, yet systematically changing, elevated firing rate profiles within the neurons of the selected PNGs. Additionally, our theory explains the relationship between such slowly changing firing rates and precisely timed spikes, and it reveals a novel relationship between WM and the perception of time on the order of seconds.

Memory for Emotional Pictures in Patients with Alzheimer's Dementia: Comparing Picture-Location Binding and Subsequent Recognition

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Marloes J. Huijbers

2011-01-01

Full Text Available Emotional content typically facilitates subsequent memory, known as the emotional enhancement effect. We investigated whether emotional content facilitates spatial and item memory in patients with Alzheimer's dementia (AD. Twenty-three AD patients, twenty-three healthy elderly, and twenty-three young adults performed a picture relocation task and a delayed recognition task with positive, negative, and neutral stimuli. AD patients showed a benefit in immediate spatial memory for positive pictures, while healthy young and older participants did not benefit from emotional content. No emotional enhancement effects on delayed item recognition were seen. We conclude that AD patients may have a memory bias for positive information in spatial memory. Discrepancies between our findings and earlier studies are discussed.

Understanding Organizational Memory from the Integrated Management Systems (ERP)

OpenAIRE

Gilberto Perez; Isabel Ramos

2013-01-01

With this research, in the form of a theoretical essay addressing the theme of Organizational Memory and Integrated Management Systems (ERP), we tried to present some evidence of how this type of system can contribute to the consolidation of certain features of Organizational Memory. From a theoretical review of the concepts of Human Memory, extending to the Organizational Memory and Information Systems, with emphasis on Integrated Management Systems (ERP) we tried to draw a parallel between ...

The Past: History or Memory

Directory of Open Access Journals (Sweden)

Olga Yanet Acuña Rodríguez

2014-07-01

facilitating a fascinating academic and intellectual debate. Secondly, this article analyzes the way in which these two concepts have been addressed in the irst six issues of Historia Y MEMORIA journal, which proposes historiography, as a ield of analysis that allows researchers in the social sciences to discuss the contributions of memory to historiographical construction, and how memory contributes to the creation of both individual and collective remembrance. In the irst six journal issues, the relationship between history and memory is found in the subject matter, theoretical approaches, use of sources and proposed methodologies, bringing us closer to alternative prognoses about the past, that include a permanent dialogue with the present.

Tier identification (TID) for tiered memory characteristics

Science.gov (United States)

Chang, Jichuan; Lim, Kevin T; Ranganathan, Parthasarathy

2014-03-25

A tier identification (TID) is to indicate a characteristic of a memory region associated with a virtual address in a tiered memory system. A thread may be serviced according to a first path based on the TID indicating a first characteristic. The thread may be serviced according to a second path based on the TID indicating a second characteristic.

Albert Einstein memorial lectures

CERN Document Server

Mechoulam, Raphael; The Israel Academy for Sciences and Humanities

2012-01-01

This volume consists of a selection of the Albert Einstein Memorial Lectures presented annually at the Israel Academy of Sciences and Humanities. Delivered by eminent scientists and scholars, including Nobel laureates, they cover a broad spectrum of subjects in physics, chemistry, life science, mathematics, historiography and social issues. This distinguished memorial lecture series was inaugurated by the Israel Academy of Sciences and Humanities following an international symposium held in Jerusalem in March 1979 to commemorate the centenary of Albert Einstein's birth. Considering that Einstein's interests, activities and influence were not restricted to theoretical physics but spanned broad fields affecting society and the welfare of humankind, it was felt that these memorial lectures should be addressed to scientists, scholars and erudite laypersons rather than to physicists alone.

Alpha power gates relevant information during working memory updating.

Science.gov (United States)

Manza, Peter; Hau, Chui Luen Vera; Leung, Hoi-Chung

2014-04-23

Human working memory (WM) is inherently limited, so we must filter out irrelevant information in our environment or our mind while retaining limited important relevant contents. Previous work suggests that neural oscillations in the alpha band (8-14 Hz) play an important role in inhibiting incoming distracting information during attention and selective encoding tasks. However, whether alpha power is involved in inhibiting no-longer-relevant content or in representing relevant WM content is still debated. To clarify this issue, we manipulated the amount of relevant/irrelevant information using a task requiring spatial WM updating while measuring neural oscillatory activity via EEG and localized current sources across the scalp using a surface Laplacian transform. An initial memory set of two, four, or six spatial locations was to be memorized over a delay until an updating cue was presented indicating that only one or three locations remained relevant for a subsequent recognition test. Alpha amplitude varied with memory maintenance and updating demands among a cluster of left frontocentral electrodes. Greater postcue alpha power was associated with the high relevant load conditions (six and four dots cued to reduce to three relevant) relative to the lower load conditions (four and two dots reduced to one). Across subjects, this difference in alpha power was correlated with condition differences in performance accuracy. In contrast, no significant effects of irrelevant load were observed. These findings demonstrate that, during WM updating, alpha power reflects maintenance of relevant memory contents rather than suppression of no-longer-relevant memory traces.

False memories in social anxiety disorder

Directory of Open Access Journals (Sweden)

PRISCILA DE CAMARGO PALMA

Full Text Available Abstract Background False memories are memories of events that never occurred or that occurred, but not exactly as we recall. Events with emotional content are subject to false memories production similar to neutral events. However, individual differences, such as the level of maladjustment and emotional instability characteristics of Social Anxiety Disorder (SAD, may interfere in the production of false memories. Objectives This study aimed to assess the effect of emotion in memory performance for an event witnessed by participants with and without SAD. Methods Participants were 61 young adults with SAD and 76 without any symptoms of SAD who were randomly assigned to watch a story with or without emotional arousal. Participants answered a subjective scale of emotion about the story and a recognition memory test. Results Participants with SAD recovered more true memories and more false memories for the non-emotional version compared to the emotional version of the story. Overall, participants with SAD produced fewer false memories compared to those without SAD. Discussion This finding suggests that social anxiety may have a significant impact on emotional memory accuracy, which may assist in the development and improvement of techniques for therapeutic intervention.

Webquests: A Strategy to Address the "Content" Dilemma in Teacher Education Coursework

Science.gov (United States)

Fero, Marie

2008-01-01

The purpose of this article is to propose the use of technology integration in elementary and middle level education courses, specifically, the use of WebQuests as vehicles for the infusion of content knowledge in preservice and in-service education courses. Observation in content area teaching methods courses found that teacher candidates often…

Quantum memory Write, read and reset

CERN Document Server

Wu Tai Tsun; Wu, Tai Tsun; Yu, Ming Lun

2002-01-01

A model is presented for the quantum memory, the content of which is a pure quantum state. In this model, the fundamental operations of writing on, reading, and resetting the memory are performed through scattering from the memory. The requirement that the quantum memory must remain in a pure state after scattering implies that the scattering is of a special type, and only certain incident waves are admissible. An example, based on the Fermi pseudo-potential in one dimension, is used to demonstrate that the requirements on the scattering process are consistent and can be satisfied. This model is compared with the commonly used model for the quantum memory; the most important difference is that the spatial dimensions and interference play a central role in the present model.

Depletion of serotonin selectively impairs short-term memory without affecting long-term memory in odor learning in the terrestrial slug Limax valentianus.

Science.gov (United States)

Shirahata, Takaaki; Tsunoda, Makoto; Santa, Tomofumi; Kirino, Yutaka; Watanabe, Satoshi

2006-01-01

The terrestrial slug Limax is able to acquire short-term and long-term memories during aversive odor-taste associative learning. We investigated the effect of the selective serotonergic neurotoxin 5,7-dihydroxytryptamine (5,7-DHT) on memory. Behavioral studies indicated that 5,7-DHT impaired short-term memory but not long-term memory. HPLC (high-performance liquid chromatography) analysis revealed that 5,7-DHT significantly reduced serotonin content in the central nervous system. The present study suggests that acquisition, retention, and/or retrieval of short-term memory involves serotonin, and neither acquisition nor retrieval of long-term memory requires serotonin at a level as high as that required for short-term memory.

A comparison of flashbacks and ordinary autobiographical memories of trauma: content and language.

Science.gov (United States)

Hellawell, Steph J; Brewin, Chris R

2004-01-01

We investigated hypotheses derived from the dual representation theory of posttraumatic stress disorder, which proposes that flashbacks and ordinary memories of trauma are supported by different types of representation. Sixty-two participants meeting diagnostic criteria for posttraumatic stress disorder completed a detailed written trauma narrative, and afterwards identified those sections in the narrative that had been written in flashback and ordinary memory periods. As predicted, flashback periods were characterised by greater use of detail, particularly perceptual detail, by more mentions of death, more use of the present tense, and more mention of fear, helplessness, and horror. In contrast, ordinary memory sections were characterised by more mention of secondary emotions such as guilt and anger.

Temporal-contextual processing in working memory: evidence from delayed cued recall and delayed free recall tests.

Science.gov (United States)

Loaiza, Vanessa M; McCabe, David P

2012-02-01

Three experiments are reported that addressed the nature of processing in working memory by investigating patterns of delayed cued recall and free recall of items initially studied during complex and simple span tasks. In Experiment 1, items initially studied during a complex span task (i.e., operation span) were more likely to be recalled after a delay in response to temporal-contextual cues, relative to items from subspan and supraspan list lengths in a simple span task (i.e., word span). In Experiment 2, items initially studied during operation span were more likely to be recalled from neighboring serial positions during delayed free recall than were items studied during word span trials. Experiment 3 demonstrated that the number of attentional refreshing opportunities strongly predicts episodic memory performance, regardless of whether the information is presented in a spaced or massed format in a modified operation span task. The results indicate that the content-context bindings created during complex span trials reflect attentional refreshing opportunities that are used to maintain items in working memory.

Dorsolateral Prefrontal Cortex GABA Concentration in Humans Predicts Working Memory Load Processing Capacity.

Science.gov (United States)

Yoon, Jong H; Grandelis, Anthony; Maddock, Richard J

2016-11-16

The discovery of neural mechanisms of working memory (WM) would significantly enhance our understanding of complex human behaviors and guide treatment development for WM-related impairments found in neuropsychiatric conditions and aging. Although the dorsolateral prefrontal cortex (DLPFC) has long been considered critical for WM, we still know little about the neural elements and pathways within the DLPFC that support WM in humans. In this study, we tested whether an individual's DLPFC gamma-aminobutryic acid (GABA) content predicts individual differences in WM task performance using a novel behavioral approach. Twenty-three healthy adults completed a task that measured the unique contribution of major WM components (memory load, maintenance, and distraction resistance) to performance. This was done to address the possibility that components have differing GABA dependencies and the failure to parse WM into components would lead to missing true associations with GABA. The subjects then had their DLPFC GABA content measured by single-voxel proton magnetic spectroscopy. We found that individuals with lower DLPFC GABA showed greater performance degradation with higher load, accounting for 31% of variance, p (corrected) = 0.015. This relationship was component, neurochemical, and brain region specific. DLPFC GABA content did not predict performance sensitivity to other components tested; DLPFC glutamate + glutamine and visual cortical GABA content did not predict load sensitivity. These results confirm the involvement of DLPFC GABA in WM load processing in humans and implicate factors controlling DLPFC GABA content in the neural mechanisms of WM and its impairments. This study demonstrated for the first time that the amount of gamma-aminobutryic acid (GABA), the major inhibitory neurotransmitter of the brain, in an individual's prefrontal cortex predicts working memory (WM) task performance. Given that WM is required for many of the most characteristic cognitive and

Martensitic transformations and the shape memory effect in Ti-Zr-Nb-Al high-temperature shape memory alloys

Energy Technology Data Exchange (ETDEWEB)

Zhang, Fei; Yu, Zhiguo; Xiong, Chengyang [School of Materials Science and Engineering, Beihang University, Beijing 100191 (China); Key Laboratory of Aerospace Materials and Performance (Ministry of Education), Beihang University, Beijing 100191 (China); Qu, Wentao; Yuan, Bifei [School of Mechanical Engineering, Xi’an Shiyou University, Xi’an 710065 (China); Wang, Zhenguo [School of Materials Science and Engineering, Beihang University, Beijing 100191 (China); Key Laboratory of Aerospace Materials and Performance (Ministry of Education), Beihang University, Beijing 100191 (China); Li, Yan, E-mail: liyan@buaa.edu.cn [School of Materials Science and Engineering, Beihang University, Beijing 100191 (China); Key Laboratory of Aerospace Materials and Performance (Ministry of Education), Beihang University, Beijing 100191 (China)

2017-01-02

The microstructures, phase transformations, mechanical properties and shape memory effect of Ti-20Zr-10Nb-xAl (x=1, 2, 3, 4 at%) alloys were investigated. The X-ray diffraction results show that the alloys are composed of a single martensitic α″-phase and that the corresponding unit cell volume decreases with increasing Al content. The reverse martensitic transformation start temperature (A{sub s}) of the Ti-20Zr-10Nb-Al alloy is 534 K and decreases with increasing Al content. The addition of Al results in solid solution strengthening and grain refinement strengthening, thus improving the mechanical properties and the shape memory effect of the Ti-20Zr-10 Nb-xAl alloys. The Ti-20Zr-10Nb-3Al alloy shows the greatest shape memory strain (3.2%) and the largest tensile strain (17.6%) as well as a very high tensile strength (886 MPa).

Structural, Synaptic, and Epigenetic Dynamics of Enduring Memories

Directory of Open Access Journals (Sweden)

Ossama Khalaf

2016-01-01

Full Text Available Our memories are the records of the experiences we gain in our everyday life. Over time, they slowly transform from an initially unstable state into a long-lasting form. Many studies have been investigating from different aspects how a memory could persist for sometimes up to decades. In this review, we highlight three of the greatly addressed mechanisms that play a central role for a given memory to endure: the allocation of the memory to a given neuronal population and what brain areas are recruited for its storage; the structural changes that underlie memory persistence; and finally the epigenetic control of gene expression that might regulate and support memory perseverance. Examining such key properties of a memory is essential towards a finer understanding of its capacity to last.

Structural, Synaptic, and Epigenetic Dynamics of Enduring Memories

Science.gov (United States)

Khalaf, Ossama; Gräff, Johannes

2016-01-01

Our memories are the records of the experiences we gain in our everyday life. Over time, they slowly transform from an initially unstable state into a long-lasting form. Many studies have been investigating from different aspects how a memory could persist for sometimes up to decades. In this review, we highlight three of the greatly addressed mechanisms that play a central role for a given memory to endure: the allocation of the memory to a given neuronal population and what brain areas are recruited for its storage; the structural changes that underlie memory persistence; and finally the epigenetic control of gene expression that might regulate and support memory perseverance. Examining such key properties of a memory is essential towards a finer understanding of its capacity to last. PMID:26933513

Event Boundaries in Memory and Cognition.

Science.gov (United States)

Radvansky, Gabriel A; Zacks, Jeffrey M

2017-10-01

Research on event cognition is rapidly developing and is revealing fundamental aspects of human cognition. In this paper, we review recent and current work that is driving this field forward. We first outline the Event Horizon Model, which broadly describes the impact of event boundaries on cognition and memory. Then, we address recent work on event segmentation, the role of event cognition in working memory and long-term memory, including event model updating, and long term retention. Throughout we also consider how event cognition varies across individuals and groups of people and consider the neural mechanisms involved.

In-memory interconnect protocol configuration registers

Energy Technology Data Exchange (ETDEWEB)

Cheng, Kevin Y.; Roberts, David A.

2017-09-19

Systems, apparatuses, and methods for moving the interconnect protocol configuration registers into the main memory space of a node. The region of memory used for storing the interconnect protocol configuration registers may also be made cacheable to reduce the latency of accesses to the interconnect protocol configuration registers. Interconnect protocol configuration registers which are used during a startup routine may be prefetched into the host's cache to make the startup routine more efficient. The interconnect protocol configuration registers for various interconnect protocols may include one or more of device capability tables, memory-side statistics (e.g., to support two-level memory data mapping decisions), advanced memory and interconnect features such as repair resources and routing tables, prefetching hints, error correcting code (ECC) bits, lists of device capabilities, set and store base address, capability, device ID, status, configuration, capabilities, and other settings.

In-memory interconnect protocol configuration registers

Science.gov (United States)

Cheng, Kevin Y.; Roberts, David A.

2017-09-19

Systems, apparatuses, and methods for moving the interconnect protocol configuration registers into the main memory space of a node. The region of memory used for storing the interconnect protocol configuration registers may also be made cacheable to reduce the latency of accesses to the interconnect protocol configuration registers. Interconnect protocol configuration registers which are used during a startup routine may be prefetched into the host's cache to make the startup routine more efficient. The interconnect protocol configuration registers for various interconnect protocols may include one or more of device capability tables, memory-side statistics (e.g., to support two-level memory data mapping decisions), advanced memory and interconnect features such as repair resources and routing tables, prefetching hints, error correcting code (ECC) bits, lists of device capabilities, set and store base address, capability, device ID, status, configuration, capabilities, and other settings.

A review of visual memory capacity: Beyond individual items and towards structured representations

OpenAIRE

Brady, Timothy F.; Konkle, Talia; Alvarez, George A.

2011-01-01

Traditional memory research has focused on identifying separate memory systems and exploring different stages of memory processing. This approach has been valuable for establishing a taxonomy of memory systems and characterizing their function, but has been less informative about the nature of stored memory representations. Recent research on visual memory has shifted towards a representation-based emphasis, focusing on the contents of memory, and attempting to determine the format and struct...

Enhancing memory self-efficacy during menopause through a group memory strategies program.

Science.gov (United States)

Unkenstein, Anne E; Bei, Bei; Bryant, Christina A

2017-05-01

Anxiety about memory during menopause can affect quality of life. We aimed to improve memory self-efficacy during menopause using a group memory strategies program. The program was run five times for a total of 32 peri- and postmenopausal women, age between 47 and 60 years, recruited from hospital menopause and gynecology clinics. The 4-week intervention consisted of weekly 2-hour sessions, and covered how memory works, memory changes related to ageing, health and lifestyle factors, and specific memory strategies. Memory contentment (CT), reported frequency of forgetting (FF), use of memory strategies, psychological distress, and attitude toward menopause were measured. A double-baseline design was applied, with outcomes measured on two baseline occasions (1-month prior [T1] and in the first session [T2]), immediately postintervention (T3), and 3-month postintervention (T4). To describe changes in each variable between time points paired sample t tests were conducted. Mixed-effects models comparing the means of random slopes from T2 to T3 with those from T1 to T2 were conducted for each variable to test for treatment effects. Examination of the naturalistic changes in outcome measures from T1 to T2 revealed no significant changes (all Ps > 0.05). CT, reported FF, and use of memory strategies improved significantly more from T2 to T3, than from T1 to T2 (all Ps attitude toward menopause nor psychological distress improved significantly more postintervention than during the double-baseline (all Ps > 0.05). Improvements in reported CT and FF were maintained after 3 months. The use of group interventions to improve memory self-efficacy during menopause warrants continued evaluation.

Projected phase-change memory devices.

Science.gov (United States)

Koelmans, Wabe W; Sebastian, Abu; Jonnalagadda, Vara Prasad; Krebs, Daniel; Dellmann, Laurent; Eleftheriou, Evangelos

2015-09-03

Nanoscale memory devices, whose resistance depends on the history of the electric signals applied, could become critical building blocks in new computing paradigms, such as brain-inspired computing and memcomputing. However, there are key challenges to overcome, such as the high programming power required, noise and resistance drift. Here, to address these, we present the concept of a projected memory device, whose distinguishing feature is that the physical mechanism of resistance storage is decoupled from the information-retrieval process. We designed and fabricated projected memory devices based on the phase-change storage mechanism and convincingly demonstrate the concept through detailed experimentation, supported by extensive modelling and finite-element simulations. The projected memory devices exhibit remarkably low drift and excellent noise performance. We also demonstrate active control and customization of the programming characteristics of the device that reliably realize a multitude of resistance states.

Non-volatile main memory management methods based on a file system.

Science.gov (United States)

Oikawa, Shuichi

2014-01-01

There are upcoming non-volatile (NV) memory technologies that provide byte addressability and high performance. PCM, MRAM, and STT-RAM are such examples. Such NV memory can be used as storage because of its data persistency without power supply while it can be used as main memory because of its high performance that matches up with DRAM. There are a number of researches that investigated its uses for main memory and storage. They were, however, conducted independently. This paper presents the methods that enables the integration of the main memory and file system management for NV memory. Such integration makes NV memory simultaneously utilized as both main memory and storage. The presented methods use a file system as their basis for the NV memory management. We implemented the proposed methods in the Linux kernel, and performed the evaluation on the QEMU system emulator. The evaluation results show that 1) the proposed methods can perform comparably to the existing DRAM memory allocator and significantly better than the page swapping, 2) their performance is affected by the internal data structures of a file system, and 3) the data structures appropriate for traditional hard disk drives do not always work effectively for byte addressable NV memory. We also performed the evaluation of the effects caused by the longer access latency of NV memory by cycle-accurate full-system simulation. The results show that the effect on page allocation cost is limited if the increase of latency is moderate.

Thinking about memories for everyday and shocking events: do people use ease-of-retrieval cues in memory judgments?

Science.gov (United States)

Echterhoff, Gerald; Hirst, William

2006-06-01

Extant research shows that people use retrieval ease, a feeling-based cue, to judge how well they remember life periods. Extending this approach, we investigated the role of retrieval ease in memory judgments for single events. In Experiment 1, participants who were asked to recall many memories of an everyday event (New Year's Eve) rated retrieval as more difficult and judged their memory as worse than did participants asked to recall only a few memories. In Experiment 2, this ease-of-retrieval effect was found to interact with the shocking character of the remembered event: There was no effect when the event was highly shocking (i.e., learning about the attacks of September 11, 2001), whereas an effect was found when the event was experienced as less shocking (due either to increased distance to "9/11" or to the nonshocking nature of the event itself). Memory vividness accounted for additional variance in memory judgments, indicating an independent contribution of content-based cues in judgments of event memories.

High capacity, high speed histogramming data acquisition memory

International Nuclear Information System (INIS)

Epstein, A.; Boulin, C.

1996-01-01

A double width CAMAC DRAM store module was developed for use as a histogramming memory in fast time-resolved synchrotron radiation applications to molecular biology. High speed direct memory modify (3 MHz) is accomplished by using a discrete DRAM controller and fast page mode access. The module can be configured using standard SIMMs to sizes of up to 64M-words. The word width is 16 bit and the module can handle overflows by storing the overflow addresses in a dedicated FIFO. Simultaneous front panel DMM/DMI access and CAMAC readout of the overflow addresses is supported

Bombesin administration impairs memory and does not reverse memory deficit caused by sleep deprivation.

Science.gov (United States)

Ferreira, L B T; Oliveira, S L B; Raya, J; Esumi, L A; Hipolide, D C

2017-07-28

Sleep deprivation impairs performance in emotional memory tasks, however this effect on memory is not completely understood. Possible mechanisms may involve an alteration in neurotransmission systems, as shown by the fact that many drugs that modulate neural pathways can prevent memory impairment by sleep loss. Gastrin releasing peptide (GRP) is a neuropeptide that emerged as a regulatory molecule of emotional memory through the modulation of other neurotransmission systems. Thus, the present study addressed the effect of intraperitoneal (IP) administration of bombesin (BB) (2.5, 5.0 and 10.0μg/kg), a GRP agonist, on the performance of Wistar rats in a multiple trail inhibitory avoidance (MTIA) task, after sleep deprivation, using the modified multiple platforms method (MMPM). Sleep deprived animals exhibited acquisition and retention impairment that was not prevented by BB injection. In addition, non-sleep deprived animals treated with BB before and after the training session, but not before the test, have shown a retention deficit. In summary, BB did not improve the memory impairment by sleep loss and, under normal conditions, produced a memory consolidation deficit. Copyright © 2017 Elsevier B.V. All rights reserved.

Processor-in-memory-and-storage architecture

Science.gov (United States)

DeBenedictis, Erik

2018-01-02

A method and apparatus for performing reliable general-purpose computing. Each sub-core of a plurality of sub-cores of a processor core processes a same instruction at a same time. A code analyzer receives a plurality of residues that represents a code word corresponding to the same instruction and an indication of whether the code word is a memory address code or a data code from the plurality of sub-cores. The code analyzer determines whether the plurality of residues are consistent or inconsistent. The code analyzer and the plurality of sub-cores perform a set of operations based on whether the code word is a memory address code or a data code and a determination of whether the plurality of residues are consistent or inconsistent.

Memory assessment in patients with temporal lobe epilepsy to predict memory impairment after surgery: A systematic review.

Science.gov (United States)

Parra-Díaz, P; García-Casares, N

2017-04-19

Given that surgical treatment of refractory mesial temporal lobe epilepsy may cause memory impairment, determining which patients are eligible for surgery is essential. However, there is little agreement on which presurgical memory assessment methods are best able to predict memory outcome after surgery and identify those patients with a greater risk of surgery-induced memory decline. We conducted a systematic literature review to determine which presurgical memory assessment methods best predict memory outcome. The literature search of PubMed gathered articles published between January 2005 and December 2015 addressing pre- and postsurgical memory assessment in mesial temporal lobe epilepsy patients by means of neuropsychological testing, functional MRI, and other neuroimaging techniques. We obtained 178 articles, 31 of which were included in our review. Most of the studies used neuropsychological tests and fMRI; these methods are considered to have the greatest predictive ability for memory impairment. Other less frequently used techniques included the Wada test and FDG-PET. Current evidence supports performing a presurgical assessment of memory function using both neuropsychological tests and functional MRI to predict memory outcome after surgery. Copyright © 2017 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

The Importance of Friends in Autobiographical Memory

DEFF Research Database (Denmark)

Antalikova, Radka; Hansen, Tia G. B.; Gulbrandsen, Knut Arild

often rehearsed, family memories that were old and rarely rehearsed, and school memories that were in between on both variables. This supports theories of friendship as the primary social context for adolescent development. Moreover, content analysis found friend memories to mention others more often......Relatedness is a complex issue and it has been argued that developmental perspectives should complement cross-cultural comparisons. We noticed that cross-cultural studies of autobiographical memories tend to focus on early childhood and thus family, leaving the role of friends and school less...... explored. Thus, we asked adolescent school-goers who still lived with their parents for a meaningful memory from each of the settings family, school, and friendship. In both samples analyzed so far (Norwegians, N=22, and Slovaks, N=40) participants chose friend memories that were recent and reportedly...

An analysis of content in comprehensive cancer control plans that address chronic hepatitis B and C virus infections as major risk factors for liver cancer.

Science.gov (United States)

Momin, Behnoosh; Richardson, Lisa

2012-08-01

Chronic hepatitis B and hepatitis C virus (HBV and HCV) infections are among the leading causes of preventable death worldwide. Chronic viral hepatitis is the cause of most primary liver cancer, which is the third leading cause of cancer deaths globally and the ninth leading cause of cancer deaths in the United States. The extent to which comprehensive cancer control (CCC) programs in states, tribal governments and organizations, territories, and Pacific Island jurisdictions address chronic hepatitis B and/or hepatitis C infections as risk factors for liver cancer or recommend interventions for liver cancer prevention in their CCC plans remains unknown. We searched CCC plans for this information using the search tool at http://www.cdc.gov/cancer/ncccp/ to access the content of plans for this information. A combination of key search terms including "liver cancer", "hepatitis", "chronic alcohol", and "alcohol abuse" were used to identify potential content regarding liver cancer risk factors and prevention. Relevant content was abstracted for further review and classification. Of 66 (Although CDC funds 65 programs, one of the Pacific Island Jurisdiction grantees is the Federated States of Micronesia (FSM). This national program supports four FSM states, each of which submits a cancer plan to CDC for a total of 69 plans. During this time period, 66 plans were available on the website.) CCC plans, 27% (n = 18) addressed liver cancer using the above-mentioned search terms. In the 23 plans that addressed HBV and/or HCV, there were 25 goals, objectives, strategies, and outcomes aimed at reducing the incidence or prevalence of HBV and/or HCV infection. While nearly a third of CCC programs identify at least one goal, objective, strategy, outcome, or prevention program to reduce cancer burden in their CCC plans, few plans discuss specific actions needed to reduce the burden of liver cancer.

A memory module for experimental data handling

Science.gov (United States)

De Blois, J.

1985-02-01

A compact CAMAC memory module for experimental data handling was developed to eliminate the need of direct memory access in computer controlled measurements. When using autonomous controllers it also makes measurements more independent of the program and enlarges the available space for programs in the memory of the micro-computer. The memory module has three modes of operation: an increment-, a list- and a fifo mode. This is achieved by connecting the main parts, being: the memory (MEM), the fifo buffer (FIFO), the address buffer (BUF), two counters (AUX and ADDR) and a readout register (ROR), by an internal 24-bit databus. The time needed for databus operations is 1 μs, for measuring cycles as well as for CAMAC cycles. The FIFO provides temporary data storage during CAMAC cycles and separates the memory part from the application part. The memory is variable from 1 to 64K (24 bits) by using different types of memory chips. The application part, which forms 1/3 of the module, will be specially designed for each application and is added to the memory chian internal connector. The memory unit will be used in Mössbauer experiments and in thermal neutron scattering experiments.

Money Enhances Memory Consolidation--But Only for Boring Material

Science.gov (United States)

Murayama, Kou; Kuhbandner, Christof

2011-01-01

Money's ability to enhance memory has received increased attention in recent research. However, previous studies have not directly addressed the time-dependent nature of monetary effects on memory, which are suggested to exist by research in cognitive neuroscience, and the possible detrimental effects of monetary rewards on learning interesting…

Prospection in Cognition: The Case for Joint Episodic-Procedural Memory in Cognitive Robotics

Directory of Open Access Journals (Sweden)

David eVernon

2015-07-01

Full Text Available Prospection lies at the core of cognition: it is the means by which an agent — a person or a cognitive robot — shifts its perspective from immediate sensory experience to anticipate future events, be they the actions of other agents or the outcome of its own actions. Prospection, accomplished by internal simulation, requires mechanisms for both perceptual imagery and motor imagery. While it is known that these two forms of imagery are tightly entwined in the mirror neuron system, we do not yet have an effective model of the mentalizing network which would provide a framework to integrate declarative episodic and procedural memory systems and to combine experiential knowledge with skillful know-how. Such a framework would be founded on joint perceptuo-motor representations. In this paper we examine the case for this form of representation, contrasting sensory-motor theory with ideo-motor theory, and we discuss how such a framework could be realized by joint episodic-procedural memory. We argue that such a representation framework has several advantages for cognitive robotics. Since episodic memory operates by recombining imperfectly recalled past experience, this allows it to simulate new or unexpected events. Furthermore, by virtue of its associative nature, joint episodic-procedural memory allows the internal simulation to be conditioned by current context, semantic memory, and the agent’s value system. Context and semantics constrain the combinatorial explosion of potential perception-action associations and allow effective action selection in the pursuit of goals, while the value system provides the motives that underpin the agent’s autonomy and cognitive development. This joint episodic-procedural memory framework is neutral regarding the final implementation of these episodic and procedural memories, which can be configured sub-symbolically as associative networks or symbolically as content-addressable image databases and databases

Scaling properties in time-varying networks with memory

Science.gov (United States)

Kim, Hyewon; Ha, Meesoon; Jeong, Hawoong

2015-12-01

The formation of network structure is mainly influenced by an individual node's activity and its memory, where activity can usually be interpreted as the individual inherent property and memory can be represented by the interaction strength between nodes. In our study, we define the activity through the appearance pattern in the time-aggregated network representation, and quantify the memory through the contact pattern of empirical temporal networks. To address the role of activity and memory in epidemics on time-varying networks, we propose temporal-pattern coarsening of activity-driven growing networks with memory. In particular, we focus on the relation between time-scale coarsening and spreading dynamics in the context of dynamic scaling and finite-size scaling. Finally, we discuss the universality issue of spreading dynamics on time-varying networks for various memory-causality tests.

Treating verbal working memory in a boy with intellectual disability

Directory of Open Access Journals (Sweden)

Margherita eOrsolini

2015-07-01

Full Text Available The present case study investigates the effects of a cognitive training of verbal working memory that was proposed for Davide, a fourteen-year-old boy diagnosed with mild intellectual disability. The program stimulated attention, inhibition, switching, and the ability to engage either in verbal dual tasks or in producing inferences after the content of a short passage had been encoded in episodic memory. Key elements in our program included (1 core training of target cognitive mechanisms; (2 guided practice emphasizing concrete strategies to engage in exercises; and (3 a variable amount of adult support. The study explored whether such a complex program produced near transfer effects on an untrained dual task assessing verbal working memory and whether effects on this and other target cognitive mechanisms (i.e., attention, inhibition and switching were long-lasting and produced far transfer effects on cognitive flexibility. The effects of the intervention program were investigated with a research design consisting of four subsequent phases lasting eight or ten weeks, each preceded and followed by testing. There was a control condition (phase 1 in which the boy received, at home, a stimulation focused on the visuospatial domain. Subsequently, there were three experimental training phases, in which stimulation in the verbal domain was first focused on attention and inhibition (phase 2a, then on switching and simple working memory tasks (phase 2b, then on complex working memory tasks (phase 3. A battery of neuropsychological tests was administered before and after each training phase and seven months after the conclusion of the intervention. The main finding was that Davide changed from being incapable of addressing the dual task request of the listening span test in the initial assessment to performing close to the normal limits of a thirteen-year-old boy in the follow-up assessment with this test, when he was fifteen years old.

Consciousness and working memory: Current trends and research perspectives.

Science.gov (United States)

Velichkovsky, Boris B

2017-10-01

Working memory has long been thought to be closely related to consciousness. However, recent empirical studies show that unconscious content may be maintained within working memory and that complex cognitive computations may be performed on-line. This promotes research on the exact relationships between consciousness and working memory. Current evidence for working memory being a conscious as well as an unconscious process is reviewed. Consciousness is shown to be considered a subset of working memory by major current theories of working memory. Evidence for unconscious elements in working memory is shown to come from visual masking and attentional blink paradigms, and from the studies of implicit working memory. It is concluded that more research is needed to explicate the relationship between consciousness and working memory. Future research directions regarding the relationship between consciousness and working memory are discussed. Copyright © 2017 Elsevier Inc. All rights reserved.

Brains of verbal memory specialists show anatomical differences in language, memory and visual systems.

Science.gov (United States)

Hartzell, James F; Davis, Ben; Melcher, David; Miceli, Gabriele; Jovicich, Jorge; Nath, Tanmay; Singh, Nandini Chatterjee; Hasson, Uri

2016-05-01

We studied a group of verbal memory specialists to determine whether intensive oral text memory is associated with structural features of hippocampal and lateral-temporal regions implicated in language processing. Professional Vedic Sanskrit Pandits in India train from childhood for around 10years in an ancient, formalized tradition of oral Sanskrit text memorization and recitation, mastering the exact pronunciation and invariant content of multiple 40,000-100,000 word oral texts. We conducted structural analysis of gray matter density, cortical thickness, local gyrification, and white matter structure, relative to matched controls. We found massive gray matter density and cortical thickness increases in Pandit brains in language, memory and visual systems, including i) bilateral lateral temporal cortices and ii) the anterior cingulate cortex and the hippocampus, regions associated with long and short-term memory. Differences in hippocampal morphometry matched those previously documented for expert spatial navigators and individuals with good verbal working memory. The findings provide unique insight into the brain organization implementing formalized oral knowledge systems. Copyright © 2015. Published by Elsevier Inc.

Measurements of a vortex transitional ndro Josephson memory cell

International Nuclear Information System (INIS)

Tahara, S.; Ishida, I.; Hidaka, M.; Nagasawa, S.; Ajisawa, Y.; Wada, Y.

1988-01-01

A novel vortex transitional NDRO Jospehson memory cell has been successfully fabricated and tested. The memory cell consists of two superconducting loops and a two-junction interferometer gate as a sense gate. The superconducting loop contains one Josephson junction and inductances, and stores single flux quantum. The memory cell employs vortex transitions in the superconducting loops for writing and reading data. The memory cell chips have been fabricated using niobium planarization process. The +-21 percent address signal current margin and the +-33 percent sense gate current margin have been obtained experimentally. The memory operation of the cell driven by the two-junction interferometer gates has been accurately demonstrated

Attention to information in working memory

OpenAIRE

Oberauer Klaus; Hein Laura

2012-01-01

Working memory retains information and makes it available for processing. People often need to hold several chunks of information available while concentrating on only one of them. This process requires selective attention to the contents of working memory. In this article we summarize evidence for both a broad focus of attention with a capacity of approximately four chunks and a narrow focus of attention that selects a single chunk at a time.

Serotonin, neural markers and memory

Directory of Open Access Journals (Sweden)

Alfredo eMeneses

2015-07-01

Full Text Available Diverse neuropsychiatric disorders present dysfunctional memory and no effective treatment exits for them; likely as result of the absence of neural markers associated to memory. Neurotransmitter systems and signaling pathways have been implicated in memory and dysfunctional memory; however, their role is poorly understood. Hence, neural markers and cerebral functions and dysfunctions are revised. To our knowledge no previous systematic works have been published addressing these issues. The interactions among behavioral tasks, control groups and molecular changes and/or pharmacological effects are mentioned. Neurotransmitter receptors and signaling pathways, during normal and abnormally functioning memory with an emphasis on the behavioral aspects of memory are revised. With focus on serotonin, since as it is a well characterized neurotransmitter, with multiple pharmacological tools, and well characterized downstream signaling in mammals’ species. 5-HT1A, 5-HT4, 5-HT5, 5-HT6 and 5-HT7 receptors as well as SERT (serotonin transporter seem to be useful neural markers and/or therapeutic targets. Certainly, if the mentioned evidence is replicated, then the translatability from preclinical and clinical studies to neural changes might be confirmed. Hypothesis and theories might provide appropriate limits and perspectives of evidence

[Nondeclarative memory--neuropsychological findings and neuroanatomic principles].

Science.gov (United States)

Daum, I; Ackermann, H

1997-03-01

The contents of long-term memory will influence behaviour, even if the acquired knowledge or the original learning episode are not remembered. These phenomena have been termed "non-declarative" or "implicit" memory, and they are contrasted with "declarative" or "explicit" memory which is characterised by conscious search and retrieval procedures. Non-declarative memory encompasses non-associative learning, simple conditioning, priming effects as well as motor, perceptual and cognitive skill acquisition. The dissociation of both forms of memory is documented by studies in health subjects which indicated that experimental manipulations or drugs may differentially affect declarative and non-declarative memory processes. Damage to the medial temporal or the medial thalamic regions is known to result in declarative memory deficits whereas non-declarative memory is largely unaffected by such lesions. Animal research and clinical findings indicate that several components of non-declarative memory such as motor and cognitive skill acquisition or certain types of classical conditioning are dependent upon the integrity of the basal ganglia or the cerebellum. These issues are therefore of increasing importance for the understanding of extrapyramidal and cerebellar diseases. This paper presents recent neuropsychological findings and neuroanatomical data relating to the issue of non-declarative memory.

Bulk-memory processor for data acquisition

International Nuclear Information System (INIS)

Nelson, R.O.; McMillan, D.E.; Sunier, J.W.; Meier, M.; Poore, R.V.

1981-01-01

To meet the diverse needs and data rate requirements at the Van de Graaff and Weapons Neutron Research (WNR) facilities, a bulk memory system has been implemented which includes a fast and flexible processor. This bulk memory processor (BMP) utilizes bit slice and microcode techniques and features a 24 bit wide internal architecture allowing direct addressing of up to 16 megawords of memory and histogramming up to 16 million counts per channel without overflow. The BMP is interfaced to the MOSTEK MK 8000 bulk memory system and to the standard MODCOMP computer I/O bus. Coding for the BMP both at the microcode level and with macro instructions is supported. The generalized data acquisition system has been extended to support the BMP in a manner transparent to the user

IP lookup with low memory requirement and fast update

DEFF Research Database (Denmark)

Berger, Michael Stübert

2003-01-01

The paper presents an IP address lookup algorithm with low memory requirement and fast updates. The scheme, which is denoted prefix-tree, uses a combination of a trie and a tree search, which is efficient in memory usage because the tree contains exactly one node for each prefix in the routing...

Are delusional contents replayed during dreams?

Science.gov (United States)

D'Agostino, Armando; Aletti, Giacomo; Carboni, Martina; Cavallotti, Simone; Limosani, Ivan; Manzone, Marialaura; Scarone, Silvio

2013-09-01

The relationship between dream content and waking life experiences remains difficult to decipher. However, some neurobiological findings suggest that dreaming can, at least in part, be considered epiphenomenal to ongoing memory consolidation processes in sleep. Both abnormalities in sleep architecture and impairment in memory consolidation mechanisms are thought to be involved in the development of psychosis. The objective of this study was to assess the continuity between delusional contents and dreams in acutely psychotic patients. Ten patients with a single fixed and recurring delusional content were asked to report their dreams during an acute psychotic break. Sixteen judges with four different levels of acquaintance to the specific content of the patients' delusions were asked to group the dreams, expecting that fragments of the delusional thought would guide the task. A mathematical index (f,t) was developed in order to compare correct groupings between the four groups of judges. Most judges grouped the dreams slightly above chance level and no relevant differences could be found between the four groups [F(3,12)=1.297; p=n.s.]. Scoring of dreams for specific delusional themes suggested a continuity in terms of dream and waking mentation for two contents (Grandiosity and Religion). These findings seem to suggest that at least some delusional contents recur within patients' dreams. Future studies will need to determine whether such continuity reflects ongoing consolidation processes that are relevant to current theories of delusion formation and stabilization. Copyright © 2013 Elsevier Inc. All rights reserved.

Rapid influences of cued visual memories on attentional guidance

NARCIS (Netherlands)

van Moorselaar, D.; Battistoni, E.; Theeuwes, J.; Olivers, C.N.L.

2015-01-01

There is evidence that the deployment of attention can be biased by the content of visual working memory. Recently, it has been shown that focusing internal attention to a specific item in memory not only increases the accessibility of that specific item for retrieval, but also results in increased

Models of working memory:Mechanisms of active maintenance and executive control (1999 Models of working memory:Mechanisms of active maintenance and executive control (1999

Directory of Open Access Journals (Sweden)

Augusto Buchweitz

2008-04-01

Full Text Available What is working memory, anyway?’ Despite the seminal definition (Baddeley & Hitch 1974; Daneman & Carpenter 1980 of working memory (WM being the system or mechanism at the basis of maintaining task-relevant information during the performance of a cognitive task (p. 1, and despite the familiarity of the term, addressing the question of what WM really is does not seem to be in the same ballpark of easily-put answers; it is not even in the same league. What is working memory, anyway?’ Despite the seminal definition (Baddeley & Hitch 1974; Daneman & Carpenter 1980 of working memory (WM being the system or mechanism at the basis of maintaining task-relevant information during the performance of a cognitive task (p. 1, and despite the familiarity of the term, addressing the question of what WM really is does not seem to be in the same ballpark of easily-put answers; it is not even in the same league.

Olfactory cues are more effective than visual cues in experimentally triggering autobiographical memories.

Science.gov (United States)

de Bruijn, Maaike J; Bender, Michael

2018-04-01

Folk wisdom often refers to odours as potent triggers for autobiographical memory, akin to the Proust phenomenon that describes Proust's sudden recollection of a childhood memory when tasting a madeleine dipped into tea. Despite an increasing number of empirical studies on the effects of odours on cognition, conclusive evidence is still missing. We set out to examine the effectiveness of childhood and non-childhood odours as retrieval cues for autobiographical memories in a lab experiment. A total of 170 participants were presented with pilot-tested retrieval cues (either odours or images) to recall childhood memories and were then asked to rate the vividness, detail, and emotional intensity of these memories. Results showed that participants indeed reported richer memories when presented with childhood-related odours than childhood-related images or childhood-unrelated odours or images. An exploratory analysis of memory content with Linguistic Inquiry and Word Count did not reveal differences in affective content. The findings of this study support the notion that odours are particularly potent in eliciting rich memories and open up numerous avenues for further exploration.

An interference model of visual working memory.

Science.gov (United States)

Oberauer, Klaus; Lin, Hsuan-Yu

2017-01-01

The article introduces an interference model of working memory for information in a continuous similarity space, such as the features of visual objects. The model incorporates the following assumptions: (a) Probability of retrieval is determined by the relative activation of each retrieval candidate at the time of retrieval; (b) activation comes from 3 sources in memory: cue-based retrieval using context cues, context-independent memory for relevant contents, and noise; (c) 1 memory object and its context can be held in the focus of attention, where it is represented with higher precision, and partly shielded against interference. The model was fit to data from 4 continuous-reproduction experiments testing working memory for colors or orientations. The experiments involved variations of set size, kind of context cues, precueing, and retro-cueing of the to-be-tested item. The interference model fit the data better than 2 competing models, the Slot-Averaging model and the Variable-Precision resource model. The interference model also fared well in comparison to several new models incorporating alternative theoretical assumptions. The experiments confirm 3 novel predictions of the interference model: (a) Nontargets intrude in recall to the extent that they are close to the target in context space; (b) similarity between target and nontarget features improves recall, and (c) precueing-but not retro-cueing-the target substantially reduces the set-size effect. The success of the interference model shows that working memory for continuous visual information works according to the same principles as working memory for more discrete (e.g., verbal) contents. Data and model codes are available at https://osf.io/wgqd5/. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Dichotic assessment of verbal memory function: development and validation of the Persian version of Dichotic Verbal Memory Test.

Science.gov (United States)

Aghamollaei, Maryam; Jafari, Zahra; Tahaei, Aliakbar; Toufan, Reyhane; Keyhani, Mohammadreza; Rahimzade, Shadi; Esmaeili, Mahdieh

2013-09-01

The Dichotic Verbal Memory Test (DVMT) is useful in detecting verbal memory deficits and differences in memory function between the brain hemispheres. The purpose of this study was to prepare the Persian version of DVMT, to obtain its results in 18- to 25-yr-old Iranian individuals, and to examine the ear, gender, and serial position effect. The Persian version of DVMT consisted of 18 10-word lists. After preparing the 18 lists, content validity was assessed by a panel of eight experts and the equivalency of the lists was evaluated. Then the words were recorded on CD in a dichotic mode such that 10 words were presented to one ear, with the same words reversed simultaneously presented to the other ear. Thereafter, it was performed on a sample of young, normal, Iranian individuals. Thirty normal individuals (no history of neurological, ontological, or psychological diseases) with ages ranging from 18 to 25 yr were examined for evaluating the equivalency of the lists, and 110 subjects within the same age range participated in the final stage of the study to obtain the normative data on the developed test. There was no significant difference between the mean scores of the 18 developed lists (p > 0.05). The mean content validity index (CVI) score was .96. A significant difference was found between the mean score of the two ears (p < 0.05) and between female and male participants (p < 0.05). The Persian version of DVMT has good content validity and can be used for verbal memory assessment in Iranian young adults. American Academy of Audiology.

On Auditing Auditory Information: The Influence of Mood on Memory for Music

Science.gov (United States)

Houston, David; Haddock, Geoffrey

2007-01-01

Previous research suggests that memory for music possesses a number of similarities to the more frequently studied modalities of verbal and visual memory. The present study addresses a yet uninvestigated factor involved in the memory for music: mood. Specifically, the study explored whether a mood-congruency effect is attained using major and…

Distinct Hippocampal versus Frontoparietal Network Contributions to Retrieval and Memory-guided Exploration.

Science.gov (United States)

Bridge, Donna J; Cohen, Neal J; Voss, Joel L

2017-08-01

Memory can profoundly influence new learning, presumably because memory optimizes exploration of to-be-learned material. Although hippocampus and frontoparietal networks have been implicated in memory-guided exploration, their specific and interactive roles have not been identified. We examined eye movements during fMRI scanning to identify neural correlates of the influences of memory retrieval on exploration and learning. After retrieval of one object in a multiobject array, viewing was strategically directed away from the retrieved object toward nonretrieved objects, such that exploration was directed toward to-be-learned content. Retrieved objects later served as optimal reminder cues, indicating that exploration caused memory to become structured around the retrieved content. Hippocampal activity was associated with memory retrieval, whereas frontoparietal activity varied with strategic viewing patterns deployed after retrieval, thus providing spatiotemporal dissociation of memory retrieval from memory-guided learning strategies. Time-lagged fMRI connectivity analyses indicated that hippocampal activity predicted frontoparietal activity to a greater extent for a condition in which retrieval guided exploration occurred than for a passive control condition in which exploration was not influenced by retrieval. This demonstrates network-level interaction effects specific to influences of memory on strategic exploration. These findings show how memory guides behavior during learning and demonstrate distinct yet interactive hippocampal-frontoparietal roles in implementing strategic exploration behaviors that determine the fate of evolving memory representations.

Distinct hippocampal versus frontoparietal-network contributions to retrieval and memory-guided exploration

Science.gov (United States)

Bridge, Donna J.; Cohen, Neal J.; Voss, Joel L.

2017-01-01

Memory can profoundly influence new learning, presumably because memory optimizes exploration of to-be-learned material. Although hippocampus and frontoparietal networks have been implicated in memory-guided exploration, their specific and interactive roles have not been identified. We examined eye movements during fMRI scanning to identify neural correlates of the influences of memory retrieval on exploration and learning. Following retrieval of one object in a multi-object array, viewing was strategically directed away from the retrieved object toward non-retrieved objects, such that exploration was directed towards to-be-learned content. Retrieved objects later served as optimal reminder cues, indicating that exploration caused memory to become structured around the retrieved content. Hippocampal activity was associated with memory retrieval whereas frontoparietal activity varied with strategic viewing patterns deployed following retrieval, thus providing spatiotemporal dissociation of memory retrieval from memory-guided learning strategies. Time-lagged fMRI connectivity analyses indicated that hippocampal activity predicted frontoparietal activity to a greater extent for a condition in which retrieval guided exploration than for a passive control condition in which exploration was not influenced by retrieval. This demonstrates network-level interaction effects specific to influences of memory on strategic exploration. These findings show how memory guides behavior during learning and demonstrate distinct yet interactive hippocampal-frontoparietal roles in implementing strategic exploration behaviors that determine the fate of evolving memory representations. PMID:28471729

Large scale particle simulations in a virtual memory computer

International Nuclear Information System (INIS)

Gray, P.C.; Million, R.; Wagner, J.S.; Tajima, T.

1983-01-01

Virtual memory computers are capable of executing large-scale particle simulations even when the memory requirements exceeds the computer core size. The required address space is automatically mapped onto slow disc memory the the operating system. When the simulation size is very large, frequent random accesses to slow memory occur during the charge accumulation and particle pushing processes. Assesses to slow memory significantly reduce the excecution rate of the simulation. We demonstrate in this paper that with the proper choice of sorting algorithm, a nominal amount of sorting to keep physically adjacent particles near particles with neighboring array indices can reduce random access to slow memory, increase the efficiency of the I/O system, and hence, reduce the required computing time. (orig.)

Large-scale particle simulations in a virtual-memory computer

International Nuclear Information System (INIS)

Gray, P.C.; Wagner, J.S.; Tajima, T.; Million, R.

1982-08-01

Virtual memory computers are capable of executing large-scale particle simulations even when the memory requirements exceed the computer core size. The required address space is automatically mapped onto slow disc memory by the operating system. When the simulation size is very large, frequent random accesses to slow memory occur during the charge accumulation and particle pushing processes. Accesses to slow memory significantly reduce the execution rate of the simulation. We demonstrate in this paper that with the proper choice of sorting algorithm, a nominal amount of sorting to keep physically adjacent particles near particles with neighboring array indices can reduce random access to slow memory, increase the efficiency of the I/O system, and hence, reduce the required computing time

Smell your way back to childhood: autobiographical odor memory.

Science.gov (United States)

Willander, Johan; Larsson, Maria

2006-04-01

This study addressed age distributions and experiential qualities of autobiographical memories evoked by different sensory cues. Ninety-three older adults were presented with one of three cue types (word, picture, or odor) and were asked to relate any autobiographical event for the given cue. The main aims were to explore whether (1) the age distribution of olfactory-evoked memories differs from memories cued by words and pictures and (2) the experiential qualities of the evoked memories vary over the different cues. The results showed that autobiographical memories triggered by olfactory information were older than memories associated with verbal and visual information. Specifically, most odor-cued memories were located to the first decade of life (memories associated with verbal and visual cues peaked in early adulthood (11-20 years). Also, odor-evoked memories were associated with stronger feelings of being brought back in time and had been thought of less often than memories evoked by verbal and visual information. This pattern of findings suggests that odor-evoked memories may be different from other memory experiences.

GAMMA BAND PLASTICITY IN SENSORY CORTEX IS A SIGNATURE OF THE STRONGEST MEMORY RATHER THAN MEMORY OF THE TRAINING STIMULUS

Science.gov (United States)

Weinberger, Norman M.; Miasnikov, Alexandre A.; Bieszczad, Kasia M.; Chen, Jemmy C.

2013-01-01

Gamma oscillations (~30–120 Hz) are considered to be a reflection of coordinated neuronal activity, linked to processes underlying synaptic integration and plasticity. Increases in gamma power within the cerebral cortex have been found during many cognitive processes such as attention, learning, memory and problem solving in both humans and animals. However, the specificity of gamma to the detailed contents of memory remains largely unknown. We investigated the relationship between learning-induced increased gamma power in the primary auditory cortex (A1) and the strength of memory for acoustic frequency. Adult male rats (n = 16) received three days (200 trials each) of pairing a tone (3.66 kHz) with stimulation of the nucleus basalis, which implanted a memory for acoustic frequency as assessed by associatively-induced disruption of ongoing behavior, viz., respiration. Post-training frequency generalization gradients (FGGs) revealed peaks at non-CS frequencies in 11/16 cases, likely reflecting normal variation in pre-training acoustic experiences. A stronger relationship was found between increased gamma power and the frequency with the strongest memory (peak of the difference between individual post- and pre-training FGGs) vs. behavioral responses to the CS training frequency. No such relationship was found for the theta/alpha band (4–15 Hz). These findings indicate that the strength of specific increased neuronal synchronization within primary sensory cortical fields can determine the specific contents of memory. PMID:23669065

Gamma band plasticity in sensory cortex is a signature of the strongest memory rather than memory of the training stimulus.

Science.gov (United States)

Weinberger, Norman M; Miasnikov, Alexandre A; Bieszczad, Kasia M; Chen, Jemmy C

2013-09-01

Gamma oscillations (∼30-120Hz) are considered to be a reflection of coordinated neuronal activity, linked to processes underlying synaptic integration and plasticity. Increases in gamma power within the cerebral cortex have been found during many cognitive processes such as attention, learning, memory and problem solving in both humans and animals. However, the specificity of gamma to the detailed contents of memory remains largely unknown. We investigated the relationship between learning-induced increased gamma power in the primary auditory cortex (A1) and the strength of memory for acoustic frequency. Adult male rats (n=16) received three days (200 trials each) of pairing a tone (3.66 kHz) with stimulation of the nucleus basalis, which implanted a memory for acoustic frequency as assessed by associatively-induced disruption of ongoing behavior, viz., respiration. Post-training frequency generalization gradients (FGGs) revealed peaks at non-CS frequencies in 11/16 cases, likely reflecting normal variation in pre-training acoustic experiences. A stronger relationship was found between increased gamma power and the frequency with the strongest memory (peak of the difference between individual post- and pre-training FGGs) vs. behavioral responses to the CS training frequency. No such relationship was found for the theta/alpha band (4-15 Hz). These findings indicate that the strength of specific increased neuronal synchronization within primary sensory cortical fields can determine the specific contents of memory. Copyright © 2013 Elsevier Inc. All rights reserved.

Emotion and autobiographical memory

Science.gov (United States)

Holland, Alisha C.; Kensinger, Elizabeth A.

2010-03-01

Autobiographical memory encompasses our recollections of specific, personal events. In this article, we review the interactions between emotion and autobiographical memory, focusing on two broad ways in which these interactions occur. First, the emotional content of an experience can influence the way in which the event is remembered. Second, emotions and emotional goals experienced at the time of autobiographical retrieval can influence the information recalled. We discuss the behavioral manifestations of each of these types of interactions and describe the neural mechanisms that may support those interactions. We discuss how findings from the clinical literature (e.g., regarding depression) and the social psychology literature (e.g., on emotion regulation) might inform future investigations of the interplay between the emotions experienced at the time of retrieval and the memories recalled, and we present ideas for future research in this domain.

The organizational memory mismatch approach in the ERP usage stage

NARCIS (Netherlands)

van Stijn, Eveline; Wensley, Anthony; Wijnhoven, Fons

2005-01-01

Enterprise Resource Planning (ERP) systems not only have a broad functional scope promising to support many different business processes. They also embed many different aspects of the company’s organizational memory. Disparities can exist between those memory contents in the ERP system and related

A memory module for experimental data handling

International Nuclear Information System (INIS)

Blois, J. de

1985-01-01

A compact CAMAC memory module for experimental data handling was developed to eliminate the need of direct memory access in computer controlled measurements. When using autonomous controllers it also makes measurements more independent of the program and enlarges the available space for programs in the memory of the micro-computer. The memory module has three modes of operation: an increment-, a list- and a fifo mode. This is achieved by connecting the main parts, being: the memory (MEM), the fifo buffer (FIFO), the address buffer (BUF), two counters (AUX and ADDR) and a readout register (ROR), by an internal 24-bit databus. The time needed for databus operations is 1 μs, for measuring cycles as well as for CAMAC cycles. The FIFO provides temporary data storage during CAMAC cycles and separates the memory part from the application part. The memory is variable from 1 to 64K (24 bits) by using different types of memory chips. The application part, which forms 1/3 of the module, will be specially designed for each application and is added to the memory by an internal connector. The memory unit will be used in Moessbauer experiments and in thermal neutron scattering experiments. (orig.)

Concealed semantic and episodic autobiographical memory electrified.

Science.gov (United States)

Ganis, Giorgio; Schendan, Haline E

2012-01-01

Electrophysiology-based concealed information tests (CIT) try to determine whether somebody possesses concealed information about a crime-related item (probe) by comparing event-related potentials (ERPs) between this item and comparison items (irrelevants). Although the broader field is sometimes referred to as "memory detection," little attention has been paid to the precise type of underlying memory involved. This study begins addressing this issue by examining the key distinction between semantic and episodic memory in the autobiographical domain within a CIT paradigm. This study also addresses the issue of whether multiple repetitions of the items over the course of the session habituate the brain responses. Participants were tested in a 3-stimulus CIT with semantic autobiographical probes (their own date of birth) and episodic autobiographical probes (a secret date learned just before the study). Results dissociated these two memory conditions on several ERP components. Semantic probes elicited a smaller frontal N2 than episodic probes, consistent with the idea that the frontal N2 decreases with greater pre-existing knowledge about the item. Likewise, semantic probes elicited a smaller central N400 than episodic probes. Semantic probes also elicited a larger P3b than episodic probes because of their richer meaning. In contrast, episodic probes elicited a larger late positive complex (LPC) than semantic probes, because of the recent episodic memory associated with them. All these ERPs showed a difference between probes and irrelevants in both memory conditions, except for the N400, which showed a difference only in the semantic condition. Finally, although repetition affected the ERPs, it did not reduce the difference between probes and irrelevants. These findings show that the type of memory associated with a probe has both theoretical and practical importance for CIT research.

Concealed semantic and episodic autobiographical memory electrified

Directory of Open Access Journals (Sweden)

Giorgio eGanis

2013-01-01

Full Text Available Electrophysiology-based concealed information tests (CIT try to determine whether somebody possesses concealed information about a probe item by comparing event-related potentials (ERPs between this item and comparison items (irrelevants. Although the broader field is sometimes referred to as memory detection, little attention has been paid to the precise type of underlying memory involved. This study begins addressing this issue by examining the key distinction between semantic and episodic memory in the autobiographical domain within a CIT paradigm. This study also addressed the issue of whether multiple repetitions of the items over the course of the session habituate the brain responses. Participants were tested in a 3-stimulus CIT with semantic autobiographical probes (their own date of birth and episodic autobiographical probes (a secret date learned just before the study. Results dissociated these two memory conditions on several ERP components. Semantic probes elicited a smaller frontal N2 than episodic probes, consistent with the idea that the frontal N2 decreases with greater pre-existing semantic knowledge about the item. Likewise, semantic probes elicited a smaller central N400 than episodic probes. Semantic probes also elicited a larger P3b than episodic probes because of their richer meaning. In contrast, episodic probes elicited a larger late positive component (LPC than semantic probes, because of the recent episodic memory associated with them. All these ERPs showed a difference between probes and irrelevants in both memory conditions, except for the N400, which showed a difference only in the semantic condition. Finally, although repetition affected the ERPs, it did not reduce the difference between probes and irrelevants. Thus, the type of memory associated with a probe has both theoretical and practical importance for CIT research.

Concealed semantic and episodic autobiographical memory electrified

Science.gov (United States)

Ganis, Giorgio; Schendan, Haline E.

2013-01-01

Electrophysiology-based concealed information tests (CIT) try to determine whether somebody possesses concealed information about a crime-related item (probe) by comparing event-related potentials (ERPs) between this item and comparison items (irrelevants). Although the broader field is sometimes referred to as “memory detection,” little attention has been paid to the precise type of underlying memory involved. This study begins addressing this issue by examining the key distinction between semantic and episodic memory in the autobiographical domain within a CIT paradigm. This study also addresses the issue of whether multiple repetitions of the items over the course of the session habituate the brain responses. Participants were tested in a 3-stimulus CIT with semantic autobiographical probes (their own date of birth) and episodic autobiographical probes (a secret date learned just before the study). Results dissociated these two memory conditions on several ERP components. Semantic probes elicited a smaller frontal N2 than episodic probes, consistent with the idea that the frontal N2 decreases with greater pre-existing knowledge about the item. Likewise, semantic probes elicited a smaller central N400 than episodic probes. Semantic probes also elicited a larger P3b than episodic probes because of their richer meaning. In contrast, episodic probes elicited a larger late positive complex (LPC) than semantic probes, because of the recent episodic memory associated with them. All these ERPs showed a difference between probes and irrelevants in both memory conditions, except for the N400, which showed a difference only in the semantic condition. Finally, although repetition affected the ERPs, it did not reduce the difference between probes and irrelevants. These findings show that the type of memory associated with a probe has both theoretical and practical importance for CIT research. PMID:23355816

Aspects of family caregiving as addressed in planned discussions between nurses, patients with chronic diseases and family caregivers: a qualitative content analysis.

Science.gov (United States)

Hagedoorn, E I; Paans, W; Jaarsma, T; Keers, J C; van der Schans, C; Luttik, M Louise

2017-01-01

Caregiving by family members of elderly with chronic conditions is currently intensifying in the context of an aging population and health care reform in the Netherlands. It is essential that nurses have attention for supporting roles of family caregivers of older patients and address family caregiving aspects on behalf of the continuity of care. This study aims to explore what aspects of family caregiving were addressed during planned discussions between nurses, patients and family caregivers in the hospital. Qualitative descriptive research was conducted using non-participant observation and audio-recordings of planned discussions between nurses, older patients and their family caregivers as they took place in the hospital. Through purposive sampling eligible patients (≥ 65 years) with one or more chronic conditions were included. These patients were admitted to the hospital for diagnostics or due to consequences of their chronic illness. Retrospective chart review was done to obtain patient characteristics. Data were collected in November/December 2013 and April/May 2014 in four hospitals. Qualitative content analysis was performed using the inductive approach in order to gain insight into addressed aspects of family caregiving. A total of 62 patients (mean age (SD) 76 years (7.2), 52% male) were included in the study, resulting in 146 planned discussions (62 admission and discharge discussions and 22 family meetings). Three themes were identified regarding addressed aspects of family caregiving. Two themes referred to aspects addressing the patients' social network, and included 'social network structure' and 'social network support'. One theme referred to aspects addressing coordination of care issues involving family caregiving, referred to as 'coordination of care'. During discussions nurses mostly addressed practical information on the patients' social network structure. When specific family caregiving support was addressed, information was limited and

How to measure working memory capacity in the change detection paradigm

NARCIS (Netherlands)

Rouder, Jeffrey N.; Morey, Richard D.; Morey, Candice C.; Cowan, Nelson

Although the measurement of working memory capacity is crucial to understanding working memory and its interaction with other cognitive faculties, there are inconsistencies in the literature on how to measure capacity. We address the measurement in the change detection paradigm, popularized by Luck

Variable resolution pattern generation for the Associative Memory of the ATLAS FTK project

CERN Document Server

Annovi, A; The ATLAS collaboration; Faulkner, G; Giannetti, P; Jiang, Z; Luongo, C; Pandini, C; Shochet, M; Tompkins, L; Volpi, G

2013-01-01

The Associative Memory (AM) chip is special device that allows to find coincidence patterns, or just patterns, between the incoming data in up to 8 parallel streams. The latest AM chip has been designed to receive silicon clusters generated in 8 layers of the ATLAS silicon detector sensor, to perform parallel track pattern matching at high rate and it will be the core of the FTK project. Data going through each of the busses are compared with a bank of patterns and AM chip looks for matches in each line, like commercial content addressable memory (CAM). The high density of hits expected in the ATLAS inner detector from 2015 put a challenge in the capability of the AM chip in rejecting random coincidences, requiring either an extremely high number of high precision patterns, with increasing costs and complexity of the system, or more flexible solutions. For this reason in the most recent prototype of the AM chip ternary cells have been added in the logic, allowing “don’t care” (DC) bits in the match. Hav...

Visual working memory contents bias ambiguous structure from motion perception.

Directory of Open Access Journals (Sweden)

Lisa Scocchia

Full Text Available The way we perceive the visual world depends crucially on the state of the observer. In the present study we show that what we are holding in working memory (WM can bias the way we perceive ambiguous structure from motion stimuli. Holding in memory the percept of an unambiguously rotating sphere influenced the perceived direction of motion of an ambiguously rotating sphere presented shortly thereafter. In particular, we found a systematic difference between congruent dominance periods where the perceived direction of the ambiguous stimulus corresponded to the direction of the unambiguous one and incongruent dominance periods. Congruent dominance periods were more frequent when participants memorized the speed of the unambiguous sphere for delayed discrimination than when they performed an immediate judgment on a change in its speed. The analysis of dominance time-course showed that a sustained tendency to perceive the same direction of motion as the prior stimulus emerged only in the WM condition, whereas in the attention condition perceptual dominance dropped to chance levels at the end of the trial. The results are explained in terms of a direct involvement of early visual areas in the active representation of visual motion in WM.

PIMS: Memristor-Based Processing-in-Memory-and-Storage.

Energy Technology Data Exchange (ETDEWEB)

Cook, Jeanine

2018-02-01

Continued progress in computing has augmented the quest for higher performance with a new quest for higher energy efficiency. This has led to the re-emergence of Processing-In-Memory (PIM) ar- chitectures that offer higher density and performance with some boost in energy efficiency. Past PIM work either integrated a standard CPU with a conventional DRAM to improve the CPU- memory link, or used a bit-level processor with Single Instruction Multiple Data (SIMD) control, but neither matched the energy consumption of the memory to the computation. We originally proposed to develop a new architecture derived from PIM that more effectively addressed energy efficiency for high performance scientific, data analytics, and neuromorphic applications. We also originally planned to implement a von Neumann architecture with arithmetic/logic units (ALUs) that matched the power consumption of an advanced storage array to maximize energy efficiency. Implementing this architecture in storage was our original idea, since by augmenting storage (in- stead of memory), the system could address both in-memory computation and applications that accessed larger data sets directly from storage, hence Processing-in-Memory-and-Storage (PIMS). However, as our research matured, we discovered several things that changed our original direc- tion, the most important being that a PIM that implements a standard von Neumann-type archi- tecture results in significant energy efficiency improvement, but only about a O(10) performance improvement. In addition to this, the emergence of new memory technologies moved us to propos- ing a non-von Neumann architecture, called Superstrider, implemented not in storage, but in a new DRAM technology called High Bandwidth Memory (HBM). HBM is a stacked DRAM tech- nology that includes a logic layer where an architecture such as Superstrider could potentially be implemented.

Detecting peripheral-based attacks on the host memory

CERN Document Server

Stewin, Patrick

2015-01-01

This work addresses stealthy peripheral-based attacks on host computers and presents a new approach to detecting them. Peripherals can be regarded as separate systems that have a dedicated processor and dedicated runtime memory to handle their tasks. The book addresses the problem that peripherals generally communicate with the host via the host’s main memory, storing cryptographic keys, passwords, opened files and other sensitive data in the process – an aspect attackers are quick to exploit.  Here, stealthy malicious software based on isolated micro-controllers is implemented to conduct an attack analysis, the results of which provide the basis for developing a novel runtime detector. The detector reveals stealthy peripheral-based attacks on the host’s main memory by exploiting certain hardware properties, while a permanent and resource-efficient measurement strategy ensures that the detector is also capable of detecting transient attacks, which can otherwise succeed when the applied strategy only me...

Memory and History: Some considerations on antinomies and paradoxes

Directory of Open Access Journals (Sweden)

J Šubrt

2015-12-01

Full Text Available Collective memory does not retain the memories of the past as historical events really happened, but as they are remembered in the present. Memory includes only elements of the past, not the past as a whole. Theoretical thinking about memory has been shaped by opinions often arising from very different starting points. This article outlines ten antinomies characterised by the following terms: individual and collective memory, spirit and matter, saving and deleting, irrevocable and revocable history, spontaneous and purposeful memory, myth and science, rationality and irrationality. The text explains that memory works in a selective way and the contents which are stored in it have no permanent form, but change over time according to the needs of the specific present. Human memory does not work as a rational machine, but rather is prone to distortions and errors. An important role in shaping collective memory is played by ideological influence and deep-rooted historical myths.

Design Guidelines for a Content-Based Image Retrieval Color-Selection Interface

NARCIS (Netherlands)

Eggen, Berry; van den Broek, Egon; van der Veer, Gerrit C.; Kisters, Peter M.F.; Willems, Rob; Vuurpijl, Louis G.

2004-01-01

In Content-Based Image Retrieval (CBIR) two query-methods exist: query-by-example and query-by-memory. The user either selects an example image or selects image features retrieved from memory (such as color, texture, spatial attributes, and shape) to define his query. Hitherto, research on CBIR

Fathers of the Nation: Barack Obama Addresses Nelson Mandela

Directory of Open Access Journals (Sweden)

Elisa Bordin

2014-11-01

Full Text Available This essay analyzes Barack Obama’s Nelson Mandela Memorial speech together with other seminal texts of Obama’s political and personal creed, such as his book Dreams from My Father (1995 and his speech “A More Perfect Union” (2008. This reading becomes helpful to understand Mandela’s transnational power, which Obama uses to comment on the United States by comparing Madiba to other American “fathers of the nation.” Thus, he uproots Mandela’s from a specifically South African legacy, expands his figure, and addresses him as a transnational father of his own nation, whose power, influence, and example transcend South African borders. As a consequence of this enlargement and transnational validation of Mandela’s figure, the speech delivered at the Memorial becomes an occasion to tackle American past and future, while the memory of Madiba and his driving example in Obama’s life serve to reinforce previous positions conveyed in other discourses by the American President, such as the “A More Perfect Union” speech delivered in Philadelphia in 2008.

Visuospatial working memory in young adults and in children with learning difficulties

OpenAIRE

Ricardo Basso Garcia

2013-01-01

Visuospatial working memory (VSWM) comprises specialised subsystems devoted to storage of visual features and spatial locations. Recently, research has been focused on understanding feature binding in memory and how bound objects are temporarily held in working memory. In the current thesis we have addressed two broad questions: What is the nature of bound visual representations in working memory? Is there a specific deficit in binding in individuals with learning difficulties? In Study 1, yo...

Multiprocessor shared-memory information exchange

International Nuclear Information System (INIS)

Santoline, L.L.; Bowers, M.D.; Crew, A.W.; Roslund, C.J.; Ghrist, W.D. III

1989-01-01

In distributed microprocessor-based instrumentation and control systems, the inter-and intra-subsystem communication requirements ultimately form the basis for the overall system architecture. This paper describes a software protocol which addresses the intra-subsystem communications problem. Specifically the protocol allows for multiple processors to exchange information via a shared-memory interface. The authors primary goal is to provide a reliable means for information to be exchanged between central application processor boards (masters) and dedicated function processor boards (slaves) in a single computer chassis. The resultant Multiprocessor Shared-Memory Information Exchange (MSMIE) protocol, a standard master-slave shared-memory interface suitable for use in nuclear safety systems, is designed to pass unidirectional buffers of information between the processors while providing a minimum, deterministic cycle time for this data exchange

Better target detection in the presence of collinear flankers under high working memory load

Directory of Open Access Journals (Sweden)

Jan W. De Fockert

2014-10-01

Full Text Available There are multiple ways in which working memory can influence selective attention. Aside from the content-specific effects of working memory on selective attention, whereby attention is more likely to be directed towards information that matches the contents of working memory, the mere level of load on working memory has also been shown to have an effect on selective attention. Specifically, high load on working memory is associated with increased processing of irrelevant information. In most demonstrations of the effect to-date, this has led to impaired target performance, leaving open the possibility that the effect partly reflects an increase in general task difficulty under high load. Here we show that working memory load can result in a performance gain when processing of distracting information aids target performance. The facilitation in the detection of a low-contrast Gabor stimulus in the presence of collinear flanking Gabors was greater when load on a concurrent working memory task was high, compared to low. This finding suggests that working memory can interact with selective attention at an early stage in visual processing.

Cultural and communicative memories: contrasting Argentina's 1976 coup d'état and the 2001 economic-political-social crisis.

Science.gov (United States)

Muller, Felipe; Bermejo, Federico; Hirst, William

2018-08-01

Studies on collective memory have recently addressed the distinction between cultural and communicative memory as a way to understand how the source of a memory affects its structure or form. When a groups' memory is mediated by memorials, documentaries or any other cultural artifacts, collective memory is shaped by cultural memory. When it is based mostly in communication with other people, its source is communicative memory. We address this distinction by studying two recent events in Argentinean history: the 2001 economic-political-social crisis (communicative memory) and the 1976 coup (cultural memory). We also examine the political ideology and the type of memory involved in collective memory. The memory of the studied events may occur during the lifetime of the rememberer (Lived Memory) or refer to distant events (Distant Memory). 100 participants responded to a Free Recall task about the events of 2001 in Argentina. Narrative analysis allowed comparing these recalls with our 1976 study. Results show: 1) Cultural memories are more contextualised, more impersonal and less affective. 2) Communicative memories are more personal and affective. Study shows how collective memory form changes when it has a different prevalent source.

Energy-aware memory management for embedded multimedia systems a computer-aided design approach

CERN Document Server

Balasa, Florin

2011-01-01

Energy-Aware Memory Management for Embedded Multimedia Systems: A Computer-Aided Design Approach presents recent computer-aided design (CAD) ideas that address memory management tasks, particularly the optimization of energy consumption in the memory subsystem. It explains how to efficiently implement CAD solutions, including theoretical methods and novel algorithms. The book covers various energy-aware design techniques, including data-dependence analysis techniques, memory size estimation methods, extensions of mapping approaches, and memory banking approaches. It shows how these techniques

A compact PE memory for vision chips

Science.gov (United States)

Cong, Shi; Zhe, Chen; Jie, Yang; Nanjian, Wu; Zhihua, Wang

2014-09-01

This paper presents a novel compact memory in the processing element (PE) for single-instruction multiple-data (SIMD) vision chips. The PE memory is constructed with 8 × 8 register cells, where one latch in the slave stage is shared by eight latches in the master stage. The memory supports simultaneous read and write on the same address in one clock cycle. Its compact area of 14.33 μm2/bit promises a higher integration level of the processor. A prototype chip with a 64 × 64 PE array is fabricated in a UMC 0.18 μm CMOS technology. Five types of the PE memory cell structure are designed and compared. The testing results demonstrate that the proposed PE memory architecture well satisfies the requirement of the vision chip in high-speed real-time vision applications, such as 1000 fps edge extraction.

A compact PE memory for vision chips

International Nuclear Information System (INIS)

Shi Cong; Chen Zhe; Yang Jie; Wu Nanjian; Wang Zhihua

2014-01-01

This paper presents a novel compact memory in the processing element (PE) for single-instruction multiple-data (SIMD) vision chips. The PE memory is constructed with 8 × 8 register cells, where one latch in the slave stage is shared by eight latches in the master stage. The memory supports simultaneous read and write on the same address in one clock cycle. Its compact area of 14.33 μm 2 /bit promises a higher integration level of the processor. A prototype chip with a 64 × 64 PE array is fabricated in a UMC 0.18 μm CMOS technology. Five types of the PE memory cell structure are designed and compared. The testing results demonstrate that the proposed PE memory architecture well satisfies the requirement of the vision chip in high-speed real-time vision applications, such as 1000 fps edge extraction. (semiconductor integrated circuits)

Thermoplastic shape-memory polyurethanes based on natural oils

International Nuclear Information System (INIS)

Saralegi, Ainara; Eceiza, Arantxa; Corcuera, Maria Angeles; Johan Foster, E; Weder, Christoph

2014-01-01

A new family of segmented thermoplastic polyurethanes with thermally activated shape-memory properties was synthesized and characterized. Polyols derived from castor oil with different molecular weights but similar chemical structures and a corn-sugar-based chain extender (propanediol) were used as starting materials in order to maximize the content of carbon from renewable resources in the new materials. The composition was systematically varied to establish a structure–property map and identify compositions with desirable shape-memory properties. The thermal characterization of the new polyurethanes revealed a microphase separated structure, where both the soft (by convention the high molecular weight diol) and the hard phases were highly crystalline. Cyclic thermo-mechanical tensile tests showed that these polymers are excellent candidates for use as thermally activated shape-memory polymers, in which the crystalline soft segments promote high shape fixity values (close to 100%) and the hard segment crystallites ensure high shape recovery values (80–100%, depending on the hard segment content). The high proportion of components from renewable resources used in the polyurethane formulation leads to the synthesis of bio-based polyurethanes with shape-memory properties. (paper)

Acetylation-mediated suppression of transcription-independent memory: bidirectional modulation of memory by acetylation.

Directory of Open Access Journals (Sweden)

Katja Merschbaecher

Full Text Available Learning induced changes in protein acetylation, mediated by histone acetyl transferases (HATs, and the antagonistic histone deacetylases (HDACs play a critical role in memory formation. The status of histone acetylation affects the interaction between the transcription-complex and DNA and thus regulates transcription-dependent processes required for long-term memory (LTM. While the majority of studies report on the role of elevated acetylation in memory facilitation, we address the impact of both, increased and decreased acetylation on formation of appetitive olfactory memory in honeybees. We show that learning-induced changes in the acetylation of histone H3 at aminoacid-positions H3K9 and H3K18 exhibit distinct and different dynamics depending on the training strength. A strong training that induces LTM leads to an immediate increase in acetylation at H3K18 that stays elevated for hours. A weak training, not sufficient to trigger LTM, causes an initial increase in acetylation at H3K18, followed by a strong reduction in acetylation at H3K18 below the control group level. Acetylation at position H3K9 is not affected by associative conditioning, indicating specific learning-induced actions on the acetylation machinery. Elevating acetylation levels by blocking HDACs after conditioning leads to an improved memory. While memory after strong training is enhanced for at least 2 days, the enhancement after weak training is restricted to 1 day. Reducing acetylation levels by blocking HAT activity after strong training leads to a suppression of transcription-dependent LTM. The memory suppression is also observed in case of weak training, which does not require transcription processes. Thus, our findings demonstrate that acetylation-mediated processes act as bidirectional regulators of memory formation that facilitate or suppress memory independent of its transcription-requirement.

Why Narrating Changes Memory: A Contribution to an Integrative Model of Memory and Narrative Processes.

Science.gov (United States)

Smorti, Andrea; Fioretti, Chiara

2016-06-01

This paper aims to reflect on the relation between autobiographical memory (ME) and autobiographical narrative (NA), examining studies on the effects of narrating on the narrator and showing how studying these relations can make more comprehensible both memory's and narrating's way of working. Studies that address explicitly on ME and NA are scarce and touch this issue indirectly. Authors consider different trends of studies of ME and NA: congruency vs incongruency hypotheses on retrieving, the way of organizing memories according to gist or verbatim format and their role in organizing positive and negative emotional experiences, the social roots of ME and NA, the rules of conversation based on narrating. Analysis of investigations leads the Authors to point out three basic results of their research. Firstly, NA transforms ME because it narrativizes memories according to a narrative format. This means that memories, when are narrated, are transformed in stories (verbal language) and socialised. Secondly, the narrativization process is determined by the act of telling something within a communicative situation. Thus, relational situation of narrating act, by modifying the story, modifies also memories. The Authors propose the RE.NA.ME model (RElation, NArration, MEmory) to understand and study ME and NA. Finally, this study claims that ME and NA refer to two different types of processes having a wide area of overlapping. This is due to common social, developmental and cultural roots that make NA to include part of ME (narrative of memory) and ME to include part of NA (memory of personal events that have been narrated).

Elements of episodic-like memory in animal models.

Science.gov (United States)

Crystal, Jonathon D

2009-03-01

Representations of unique events from one's past constitute the content of episodic memories. A number of studies with non-human animals have revealed that animals remember specific episodes from their past (referred to as episodic-like memory). The development of animal models of memory holds enormous potential for gaining insight into the biological bases of human memory. Specifically, given the extensive knowledge of the rodent brain, the development of rodent models of episodic memory would open new opportunities to explore the neuroanatomical, neurochemical, neurophysiological, and molecular mechanisms of memory. Development of such animal models holds enormous potential for studying functional changes in episodic memory in animal models of Alzheimer's disease, amnesia, and other human memory pathologies. This article reviews several approaches that have been used to assess episodic-like memory in animals. The approaches reviewed include the discrimination of what, where, and when in a radial arm maze, dissociation of recollection and familiarity, object recognition, binding, unexpected questions, and anticipation of a reproductive state. The diversity of approaches may promote the development of converging lines of evidence on the difficult problem of assessing episodic-like memory in animals.

Video content analysis on body-worn cameras for retrospective investigation

Science.gov (United States)

Bouma, Henri; Baan, Jan; ter Haar, Frank B.; Eendebak, Pieter T.; den Hollander, Richard J. M.; Burghouts, Gertjan J.; Wijn, Remco; van den Broek, Sebastiaan P.; van Rest, Jeroen H. C.

2015-10-01

In the security domain, cameras are important to assess critical situations. Apart from fixed surveillance cameras we observe an increasing number of sensors on mobile platforms, such as drones, vehicles and persons. Mobile cameras allow rapid and local deployment, enabling many novel applications and effects, such as the reduction of violence between police and citizens. However, the increased use of bodycams also creates potential challenges. For example: how can end-users extract information from the abundance of video, how can the information be presented, and how can an officer retrieve information efficiently? Nevertheless, such video gives the opportunity to stimulate the professionals' memory, and support complete and accurate reporting. In this paper, we show how video content analysis (VCA) can address these challenges and seize these opportunities. To this end, we focus on methods for creating a complete summary of the video, which allows quick retrieval of relevant fragments. The content analysis for summarization consists of several components, such as stabilization, scene selection, motion estimation, localization, pedestrian tracking and action recognition in the video from a bodycam. The different components and visual representations of summaries are presented for retrospective investigation.

What drives memory-driven attentional capture? The effects of memory type, display type and search type

NARCIS (Netherlands)

Olivers, C.N.L.

2009-01-01

An important question is whether visual attention (the ability to select relevant visual information) and visual working memory (the ability to retain relevant visual information) share the same content representations. Some past research has indicated that they do: Singleton distractors interfered

Natural memory beyond the storage model: Repression, trauma, and the construction of a personal past

Directory of Open Access Journals (Sweden)

Nikolai Axmacher

2010-11-01

Full Text Available Naturally occurring memory processes show features which are difficult to investigate by conventional cognitive neuroscience paradigms. Distortions of memory for problematic contents are described both by psychoanalysis (internal conflicts and research on post-traumatic stress disorder (external traumata. Typically, declarative memory for these contents is impaired – possibly due to repression in the case of internal conflicts or due to dissociation in the case of external traumata – but they continue to exert an unconscious pathological influence: neurotic symptoms or psychosomatic disorders after repression or flashbacks and intrusions in post-traumatic stress disorder after dissociation. Several experimental paradigms aim at investigating repression in healthy control subjects. We argue that these paradigms do not adequately operationalize the clinical process of repression, because they rely on an intentional inhibition of random stimuli (suppression. Furthermore, these paradigms ignore that memory distortions due to repression or dissociation are most accurately characterized by a lack of self-referential processing, resulting in an impaired integration of these contents into the self. This aspect of repression and dissociation cannot be captured by the concept of memory as a storage device which is usually employed in the cognitive neurosciences. It can only be assessed within the framework of a constructivist memory concept, according to which successful memory involves a reconstruction of experiences such that they fit into a representation of the self. We suggest several experimental paradigms that allow for the investigation of the neural correlates of repressed memories and trauma-induced memory distortions based on a constructivist memory concept.

Topical Session on 'Addressing Issues Raised by Stakeholders: Impacts on Process, Content and Behaviour in Waste Organisations'

International Nuclear Information System (INIS)

2004-01-01

At its 5. meeting in June 2004, the FSC held a topical session aimed at reviewing how organisations are adapting to the new outreach and decision-making context. Eleven organisations from eight countries provided the relevant information, which are collected in these proceedings. Learning and adapting to societal requirements - and organising institutions accordingly - is one of the main aspects of the future programme of work of the FSC. This topical session on 'Addressing Issues Raised by Stakeholders: Impacts on Process, Content and Behaviour in Waste Organisations' provides useful material for future initiatives as well as a source of information to interested stakeholders and practitioners. It focused on how regulators and implementers responded and are restructuring to respond to stakeholders' concerns, issues and needs regarding radioactive waste management

Parallel structures in human and computer memory

Science.gov (United States)

Kanerva, Pentti

1986-08-01

If we think of our experiences as being recorded continuously on film, then human memory can be compared to a film library that is indexed by the contents of the film strips stored in it. Moreover, approximate retrieval cues suffice to retrieve information stored in this library: We recognize a familiar person in a fuzzy photograph or a familiar tune played on a strange instrument. This paper is about how to construct a computer memory that would allow a computer to recognize patterns and to recall sequences the way humans do. Such a memory is remarkably similar in structure to a conventional computer memory and also to the neural circuits in the cortex of the cerebellum of the human brain. The paper concludes that the frame problem of artificial intelligence could be solved by the use of such a memory if we were able to encode information about the world properly.

A New Contention Management Technique for Obstruction Free Transactional Memory

OpenAIRE

Ghosh, Ammlan; Sahin, Anubhab; Silsarma, Anirban; Chaki, Rituparna

2014-01-01

Part 2: Algorithms; International audience; Transactional Memory, one of the most viable alternatives to lock based concurrent systems, was explored by the researchers for practically implementing parallel processing. The goal was that threads will run parallel and improve system performance, but the effect of their execution will be linear. In STM, the non-blocking synchronization can be implemented by Wait-Freedom, Lock-Freedom or Obstruction-Freedom philosophy. Though Obstruction Free Tran...

Preservation of Records, Knowledge and Memory Across Generations. Reference Bibliography within the NEA RK and M Project

International Nuclear Information System (INIS)

2016-01-01

This bibliography aims at providing an overview over the work performed in the field of the preservation of records, knowledge and memory in relation with radioactive waste management, especially disposal. For each entry, an abstract outlining the relevance of the document to the topic of RKM is provided. The following criteria are currently used to select the references: - The document (or at least part of it) addresses the preservation of RKM in connection with the management of radioactive waste - The document is publicly available or can be made available upon request - One synthesis document (such as a report) is preferable to a list of papers with a similar content. - Original documents (scientific reports and papers) are preferred to reviews or press coverage. The bibliography should help the participants in the project to identify the topics of concern in the field of RKM and, eventually, the issues that have not yet been addressed. The current bibliography is not meant to be an all-encompassing list that includes any generic reference that might be useful in the study of those topics. Therefore it does not include: - general studies outside RWM, e.g. on memory loss, communication, or the history of institutions - studies belonging to the field of RWM but that are only indirectly related to RKM preservation

Read method compensating parasitic sneak currents in a crossbar memristive memory

KAUST Repository

Zidan, Mohammed A.; Omran, Hesham; Naous, Rawan; Salem, Ahmed Sultan; Salama, Khaled N.

2017-01-01

properties of the computer memory system to address this sneak-paths problem. The method of the invention is a method for reading a target memory cell located at an intersection of a target row of a gateless array and a target column of the gateless array

Argentines' collective memories of the military Junta of 1976: differences and similarities across generations and ideology.

Science.gov (United States)

Muller, Felipe; Bermejo, Federico; Hirst, William

2016-08-01

Although memories about a nation's past usually are semantic in nature, a distinction needs to be made between lived and distant semantic collective memories. The former refers to memories of community-relevant events occurring during the lifetime of the rememberer, whereas the latter to memories of distant events. Does the content of lived and distant semantic collective memories differ? Employing both free and cued recall, we examined the memories of younger and older Argentines of the Military Junta of 1976. We also examined the effects of political ideology. Content analysis indicated that (1) lived semantic collective memories were more likely to contain personal recollections than distant semantic collective memories, even though those with distant semantic collective memories could have incorporated memories of the parent's personal experience in their recollections, (2) lived semantic collective memories contained more causal statements, and (3) those on the Right with distant semantic collective memories were more likely to claim that they "Don't know" or offer positive accounts of the Junta, suggesting a need to "defend" the reputation of those on the Right. The results are discussed in terms of the goals and plans different generations might have when recollecting their nation's past.

Preschool children's proto-episodic memory assessed by deferred imitation.

Science.gov (United States)

Burns, Patrick; Russell, Charlotte; Russell, James

2015-01-01

In two experiments, both employing deferred imitation, we studied the developmental origins of episodic memory in two- to three-year-old children by adopting a "minimalist" view of episodic memory based on its What-When-Where ("WWW": spatiotemporal plus semantic) content. We argued that the temporal element within spatiotemporal should be the order/simultaneity of the event elements, but that it is not clear whether the spatial content should be egocentric or allocentric. We also argued that episodic recollection should be configural (tending towards all-or-nothing recall of the WWW elements). Our first deferred imitation experiment, using a two-dimensional (2D) display, produced superior-to-chance performance after 2.5 years but no evidence of configural memory. Moreover, performance did not differ from that on a What-What-What control task. Our second deferred imitation study required the children to reproduce actions on an object in a room, thereby affording layout-based spatial cues. In this case, not only was there superior-to-chance performance after 2.5 years but memory was also configural at both ages. We discuss the importance of allocentric spatial cues in episodic recall in early proto-episodic memory and reflect on the possible role of hippocampal development in this process.

Tracking the Time-Dependent Role of the Hippocampus in Memory Recall Using DREADDs.

Science.gov (United States)

Varela, Carmen; Weiss, Sarah; Meyer, Retsina; Halassa, Michael; Biedenkapp, Joseph; Wilson, Matthew A; Goosens, Ki Ann; Bendor, Daniel

2016-01-01

The hippocampus is critical for the storage of new autobiographical experiences as memories. Following an initial encoding stage in the hippocampus, memories undergo a process of systems-level consolidation, which leads to greater stability through time and an increased reliance on neocortical areas for retrieval. The extent to which the retrieval of these consolidated memories still requires the hippocampus is unclear, as both spared and severely degraded remote memory recall have been reported following post-training hippocampal lesions. One difficulty in definitively addressing the role of the hippocampus in remote memory retrieval is the precision with which the entire volume of the hippocampal region can be inactivated. To address this issue, we used Designer Receptors Exclusively Activated by Designer Drugs (DREADDs), a chemical-genetic tool capable of highly specific neuronal manipulation over large volumes of brain tissue. We find that remote (>7 weeks after acquisition), but not recent (1-2 days after acquisition) contextual fear memories can be recalled after injection of the DREADD agonist (CNO) in animals expressing the inhibitory DREADD in the entire hippocampus. Our data demonstrate a time-dependent role of the hippocampus in memory retrieval, supporting the standard model of systems consolidation.

Organizational memory and the completeness of process modeling in ERP systems

NARCIS (Netherlands)

van Stijn, E.J.; Wensley, A.K.P.

2001-01-01

Enterprise resource planning (ERP) systems not only have a broad functional scope promising to support many different business processes, they also embed many different aspects of the company’s organizational memory. Disparities can exist between those memory contents in the ERP system and related

Episodic-like memory in the rat.

Science.gov (United States)

Babb, Stephanie J; Crystal, Jonathon D

2006-07-11

A fundamental question in comparative cognition is whether animals remember unique, personal past experiences. It has long been argued that memories for specific events (referred to as episodic memory) are unique to humans. Recently, considerable evidence has accumulated to show that food-storing birds possess critical behavioral elements of episodic memory, referred to as episodic-like memory in acknowledgment of the fact that behavioral criteria do not assess subjective experiences. Here we show that rats have a detailed representation of remembered events and meet behavioral criteria for episodic-like memory. We provided rats with access to locations baited with distinctive (e.g., grape and raspberry) or nondistinctive (regular chow) flavors. Locations with a distinctive flavor replenished after a long but not a short delay, and locations with the nondistinctive flavor never replenished. One distinctive flavor was devalued after encoding its location by prefeeding that flavor (satiation) or by pairing it with lithium chloride (acquired taste aversion), while the other distinctive flavor was not devalued. The rats selectively decreased revisits to the devalued distinctive flavor but not to the nondevalued distinctive flavor. The present studies demonstrate that rats selectively encode the content of episodic-like memories.

False memories with age: Neural and cognitive underpinnings.

Science.gov (United States)

Devitt, Aleea L; Schacter, Daniel L

2016-10-01

As we age we become increasingly susceptible to memory distortions and inaccuracies. Over the past decade numerous neuroimaging studies have attempted to illuminate the neural underpinnings of aging and false memory. Here we review these studies, and link their findings with those concerning the cognitive properties of age-related changes in memory accuracy. Collectively this evidence points towards a prominent role for age-related declines in medial temporal and prefrontal brain areas, and corresponding impairments in associative binding and strategic monitoring. A resulting cascade of cognitive changes contributes to the heightened vulnerability to false memories with age, including reduced recollective ability, a reliance on gist information and familiarity-based monitoring mechanisms, as well as a reduced ability to inhibit irrelevant information and erroneous binding of features between memory traces. We consider both theoretical and applied implications of research on aging and false memories, as well as questions remaining to be addressed in future research. Copyright © 2016 Elsevier Ltd. All rights reserved.

False memories with age: neural and cognitive underpinnings

Science.gov (United States)

Devitt, Aleea L.; Schacter, Daniel L.

2016-01-01

As we age we become increasingly susceptible to memory distortions and inaccuracies. Over the past decade numerous neuroimaging studies have attempted to illuminate the neural underpinnings of aging and false memory. Here we review these studies, and link their findings with those concerning the cognitive properties of age-related changes in memory accuracy. Collectively this evidence points towards a prominent role for age-related declines in medial temporal and prefrontal brain areas, and corresponding impairments in associative binding and strategic monitoring. A resulting cascade of cognitive changes contributes to the heightened vulnerability to false memories with age, including reduced recollective ability, a reliance on gist information and familiarity-based monitoring mechanisms, as well as a reduced ability to inhibit irrelevant information and erroneous binding of features between memory traces. We consider both theoretical and applied implications of research on aging and false memories, as well as questions remaining to be addressed in future research. PMID:27592332

Combating Memory Corruption Attacks On Scada Devices

Science.gov (United States)

Bellettini, Carlo; Rrushi, Julian

Memory corruption attacks on SCADA devices can cause significant disruptions to control systems and the industrial processes they operate. However, despite the presence of numerous memory corruption vulnerabilities, few, if any, techniques have been proposed for addressing the vulnerabilities or for combating memory corruption attacks. This paper describes a technique for defending against memory corruption attacks by enforcing logical boundaries between potentially hostile data and safe data in protected processes. The technique encrypts all input data using random keys; the encrypted data is stored in main memory and is decrypted according to the principle of least privilege just before it is processed by the CPU. The defensive technique affects the precision with which attackers can corrupt control data and pure data, protecting against code injection and arc injection attacks, and alleviating problems posed by the incomparability of mitigation techniques. An experimental evaluation involving the popular Modbus protocol demonstrates the feasibility and efficiency of the defensive technique.

Sleep Deprivation affects Extinction but Not Acquisition Memory in Honeybees

Science.gov (United States)

Hussaini, Syed Abid; Bogusch, Lisa; Landgraf, Tim; Menzel, Randolf

2009-01-01

Sleep-like behavior has been studied in honeybees before, but the relationship between sleep and memory formation has not been explored. Here we describe a new approach to address the question if sleep in bees, like in other animals, improves memory consolidation. Restrained bees were observed by a web camera, and their antennal activities were…

Categorising Resources of Historical Memory in Researching Publicistic Text

Directory of Open Access Journals (Sweden)

Konyk Anastasiya

2016-12-01

Full Text Available The article focuses on the allocation and analysis of the main resources of historical memory which are considered as peculiar indicators for studying publicist content and conceptual reading of discourses of historical memory in contemporary publications. It is relevant insofar as researching the use and intensification of these or other resources of historical memory allows us to observe changes in world landmarks, socio-political moods, ideological references and temperament and the dynamics of re-interpretation of historical facts and events by authors.

Violent and sexual media impair second-language memory during encoding and retrieval

NARCIS (Netherlands)

Lull, R.B.; Cetin, Y.; Bushman, B.J.

2015-01-01

Research suggests that exposure to media containing violence and sex impairs attention and memory. Learning a foreign language is one domain in which attention and memory are critical. Two experiments addressed whether exposure to media containing violence and sex interferes with foreign-language

The Distributed Nature of Working Memory

NARCIS (Netherlands)

Christophel, Thomas B.; Klink, P. Christiaan; Spitzer, Bernhard; Roelfsema, Pieter R.; Haynes, John-Dylan

2017-01-01

Studies in humans and non-human primates have provided evidence for storage of working memory contents in multiple regions ranging from sensory to parietal and prefrontal cortex. We discuss potential explanations for these distributed representations: (i) features in sensory regions versus

Development in the Organization of Episodic Memories in Middle Childhood and Adolescence

OpenAIRE

Yan eChen; Helena Margaret McAnally; Elaine eReese

2013-01-01

The basic elements of autobiographical or episodic memory are established in early childhood, although the exact age at which memories gain episodic status is still under contention. The self-memory system proposed that adults use “lifetime periods” to group episodic memories together into chapters of the life story – an evolving and internalized account of significant life events that are self-defining. Two studies examined at what point in development children or adolescents begin to take a...

Short-term memory in the service of executive control functions

OpenAIRE

Farshad Alizadeh Mansouri; Marcello eRosa; Nafiseh eAtapour

2015-01-01

Short-term memory is a crucial cognitive function for supporting on-going and upcoming behaviours, allowing storage of information across delay periods. The content of this memory may typically include tangible information about features such as the shape, colour or texture of an object, its location and motion relative to the body, or phonological information. The neural correlate of these short-term memories has been found in different brain areas involved in organizing perceptual or motor ...

The cellular memory disc of reprogrammed cells.

Science.gov (United States)

Anjamrooz, Seyed Hadi

2013-04-01

The crucial facts underlying the low efficiency of cellular reprogramming are poorly understood. Cellular reprogramming occurs in nuclear transfer, induced pluripotent stem cell (iPSC) formation, cell fusion, and lineage-switching experiments. Despite these advances, there are three fundamental problems to be addressed: (1) the majority of cells cannot be reprogrammed, (2) the efficiency of reprogramming cells is usually low, and (3) the reprogrammed cells developed from a patient's own cells activate immune responses. These shortcomings present major obstacles for using reprogramming approaches in customised cell therapy. In this Perspective, the author synthesises past and present observations in the field of cellular reprogramming to propose a theoretical picture of the cellular memory disc. The current hypothesis is that all cells undergo an endogenous and exogenous holographic memorisation such that parts of the cellular memory dramatically decrease the efficiency of reprogramming cells, act like a barrier against reprogramming in the majority of cells, and activate immune responses. Accordingly, the focus of this review is mainly to describe the cellular memory disc (CMD). Based on the present theory, cellular memory includes three parts: a reprogramming-resistance memory (RRM), a switch-promoting memory (SPM) and a culture-induced memory (CIM). The cellular memory arises genetically, epigenetically and non-genetically and affects cellular behaviours. [corrected].

Automated processing of massive audio/video content using FFmpeg

Directory of Open Access Journals (Sweden)

Kia Siang Hock

2014-01-01

Full Text Available Audio and video content forms an integral, important and expanding part of the digital collections in libraries and archives world-wide. While these memory institutions are familiar and well-versed in the management of more conventional materials such as books, periodicals, ephemera and images, the handling of audio (e.g., oral history recordings and video content (e.g., audio-visual recordings, broadcast content requires additional toolkits. In particular, a robust and comprehensive tool that provides a programmable interface is indispensable when dealing with tens of thousands of hours of audio and video content. FFmpeg is comprehensive and well-established open source software that is capable of the full-range of audio/video processing tasks (such as encode, decode, transcode, mux, demux, stream and filter. It is also capable of handling a wide-range of audio and video formats, a unique challenge in memory institutions. It comes with a command line interface, as well as a set of developer libraries that can be incorporated into applications.

Comparison of neural activity that leads to true memories, false memories, and forgetting: An fMRI study of the misinformation effect.

Science.gov (United States)

Baym, Carol L; Gonsalves, Brian D

2010-09-01

False memories can occur when people are exposed to misinformation about a past event. Of interest here are the neural mechanisms of this type of memory failure. In the present study, participants viewed photographic vignettes of common activities during an original event phase (OEP), while we monitored their brain activity using fMRI. Later, in a misinformation phase, participants viewed sentences describing the studied photographs, some of which contained information conflicting with that depicted in the photographs. One day later, participants returned for a surprise item memory recognition test for the content of the photographs. Results showed reliable creation of false memories, in that participants reported information that had been presented in the verbal misinformation but not in the photographs. Several regions were more active during the OEP for later accurate memory than for forgetting, but they were also more active for later false memories, indicating that false memories in this paradigm are not simply caused by failure to encode the original event. There was greater activation in the ventral visual stream for subsequent true memories than for subsequent false memories, however, suggesting that differences in encoding may contribute to later susceptibility to misinformation.

Quantifying Precision and Availability of Location Memory in Everyday Pictures and Some Implications for Picture Database Design

Science.gov (United States)

Lansdale, Mark W.; Oliff, Lynda; Baguley, Thom S.

2005-01-01

The authors investigated whether memory for object locations in pictures could be exploited to address known difficulties of designing query languages for picture databases. M. W. Lansdale's (1998) model of location memory was adapted to 4 experiments observing memory for everyday pictures. These experiments showed that location memory is…

Mechanical properties and shape memory effect of thermal-responsive polymer based on PVA

Science.gov (United States)

Lin, Liulan; Zhang, Lingfeng; Guo, Yanwei

2018-01-01

In this study, the effect of content of glutaraldehyde (GA) on the shape memory behavior of a shape memory polymer based on polyvinyl alcohol chemically cross-linked with GA was investigated. Thermal-responsive shape memory composites with three different GA levels, GA-PVA (3 wt%, 5 wt%, 7 wt%), were prepared by particle melting, mold forming and freeze-drying technique. The mechanical properties, thermal properties and shape memory behavior were measured by differential scanning calorimeter, physical bending test and cyclic thermo-mechanical test. The addition of GA to PVA led to a steady shape memory transition temperature and an improved mechanical compressive strength. The composite with 5 wt% of GA exhibited the best shape recoverability. Further increase in the crosslinking agent content of GA would reduce the recovery force and prolong the recovery time due to restriction in the movement of the soft PVA chain segments. These results provide important information for the study on materials in 4D printing.

Hippocampal-medial prefrontal circuit supports memory updating during learning and post-encoding rest

Science.gov (United States)

Schlichting, Margaret L.; Preston, Alison R.

2015-01-01

Learning occurs in the context of existing memories. Encountering new information that relates to prior knowledge may trigger integration, whereby established memories are updated to incorporate new content. Here, we provide a critical test of recent theories suggesting hippocampal (HPC) and medial prefrontal (MPFC) involvement in integration, both during and immediately following encoding. Human participants with established memories for a set of initial (AB) associations underwent fMRI scanning during passive rest and encoding of new related (BC) and unrelated (XY) pairs. We show that HPC-MPFC functional coupling during learning was more predictive of trial-by-trial memory for associations related to prior knowledge relative to unrelated associations. Moreover, the degree to which HPC-MPFC functional coupling was enhanced following overlapping encoding was related to memory integration behavior across participants. We observed a dissociation between anterior and posterior MPFC, with integration signatures during post-encoding rest specifically in the posterior subregion. These results highlight the persistence of integration signatures into post-encoding periods, indicating continued processing of interrelated memories during rest. We also interrogated the coherence of white matter tracts to assess the hypothesis that integration behavior would be related to the integrity of the underlying anatomical pathways. Consistent with our predictions, more coherent HPC-MPFC white matter structure was associated with better performance across participants. This HPC-MPFC circuit also interacted with content-sensitive visual cortex during learning and rest, consistent with reinstatement of prior knowledge to enable updating. These results show that the HPC-MPFC circuit supports on- and offline integration of new content into memory. PMID:26608407

Lateral Habenula determines long-term storage of aversive memories.

Directory of Open Access Journals (Sweden)

Micol eTomaiuolo

2014-05-01

Full Text Available The Lateral Habenula (LHb is a small brain structure that codifies negative motivational value and has been related to major depression. It has been shown recently that LHb activation is sufficient to induce aversive associative learning; however the key question about whether LHb activation is required for an aversive memory to be formed has not been addressed. In this article we studied the function of the LHb in memory formation using the Inhibitory Avoidance task (IA. We found that LHb inactivation during IA training does not disrupt memory when assessed 24 hours after, but abolishes it 7 days later, indicating that LHb activity during memory acquisition is not necessary for memory formation, but regulates its temporal stability. These effects suggest that LHb inactivation modifies subjective perception of the training experience.

Temporal Organization of Sound Information in Auditory Memory

Directory of Open Access Journals (Sweden)

Kun Song

2017-06-01

Full Text Available Memory is a constructive and organizational process. Instead of being stored with all the fine details, external information is reorganized and structured at certain spatiotemporal scales. It is well acknowledged that time plays a central role in audition by segmenting sound inputs into temporal chunks of appropriate length. However, it remains largely unknown whether critical temporal structures exist to mediate sound representation in auditory memory. To address the issue, here we designed an auditory memory transferring study, by combining a previously developed unsupervised white noise memory paradigm with a reversed sound manipulation method. Specifically, we systematically measured the memory transferring from a random white noise sound to its locally temporal reversed version on various temporal scales in seven experiments. We demonstrate a U-shape memory-transferring pattern with the minimum value around temporal scale of 200 ms. Furthermore, neither auditory perceptual similarity nor physical similarity as a function of the manipulating temporal scale can account for the memory-transferring results. Our results suggest that sounds are not stored with all the fine spectrotemporal details but are organized and structured at discrete temporal chunks in long-term auditory memory representation.

Temporal Organization of Sound Information in Auditory Memory.

Science.gov (United States)

Song, Kun; Luo, Huan

2017-01-01

Memory is a constructive and organizational process. Instead of being stored with all the fine details, external information is reorganized and structured at certain spatiotemporal scales. It is well acknowledged that time plays a central role in audition by segmenting sound inputs into temporal chunks of appropriate length. However, it remains largely unknown whether critical temporal structures exist to mediate sound representation in auditory memory. To address the issue, here we designed an auditory memory transferring study, by combining a previously developed unsupervised white noise memory paradigm with a reversed sound manipulation method. Specifically, we systematically measured the memory transferring from a random white noise sound to its locally temporal reversed version on various temporal scales in seven experiments. We demonstrate a U-shape memory-transferring pattern with the minimum value around temporal scale of 200 ms. Furthermore, neither auditory perceptual similarity nor physical similarity as a function of the manipulating temporal scale can account for the memory-transferring results. Our results suggest that sounds are not stored with all the fine spectrotemporal details but are organized and structured at discrete temporal chunks in long-term auditory memory representation.

Similarity-based distortion of visual short-term memory is due to perceptual averaging.

Science.gov (United States)

Dubé, Chad; Zhou, Feng; Kahana, Michael J; Sekuler, Robert

2014-03-01

A task-irrelevant stimulus can distort recall from visual short-term memory (VSTM). Specifically, reproduction of a task-relevant memory item is biased in the direction of the irrelevant memory item (Huang & Sekuler, 2010a). The present study addresses the hypothesis that such effects reflect the influence of neural averaging under conditions of uncertainty about the contents of VSTM (Alvarez, 2011; Ball & Sekuler, 1980). We manipulated subjects' attention to relevant and irrelevant study items whose similarity relationships were held constant, while varying how similar the study items were to a subsequent recognition probe. On each trial, subjects were shown one or two Gabor patches, followed by the probe; their task was to indicate whether the probe matched one of the study items. A brief cue told subjects which Gabor, first or second, would serve as that trial's target item. Critically, this cue appeared either before, between, or after the study items. A distributional analysis of the resulting mnemometric functions showed an inflation in probability density in the region spanning the spatial frequency of the average of the two memory items. This effect, due to an elevation in false alarms to probes matching the perceptual average, was diminished when cues were presented before both study items. These results suggest that (a) perceptual averages are computed obligatorily and (b) perceptual averages are relied upon to a greater extent when item representations are weakened. Implications of these results for theories of VSTM are discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

Temporal Organization of Sound Information in Auditory Memory

OpenAIRE

Song, Kun; Luo, Huan

2017-01-01

Memory is a constructive and organizational process. Instead of being stored with all the fine details, external information is reorganized and structured at certain spatiotemporal scales. It is well acknowledged that time plays a central role in audition by segmenting sound inputs into temporal chunks of appropriate length. However, it remains largely unknown whether critical temporal structures exist to mediate sound representation in auditory memory. To address the issue, here we designed ...

The emotional and reconstructive determinants of emotional memories: an experimental approach to flashbulb memory investigation.

Science.gov (United States)

Lanciano, Tiziana; Curci, Antonietta; Semin, Gun R

2010-07-01

Flashbulb memories (FBMs) are vivid and detailed memories of the reception context of a public emotional event. Brown and Kulik (1977) introduced the label FBM to suggest the idea that individuals are able to preserve knowledge of an event in an indiscriminate way, in analogy with a photograph that preserves all details of a scene. Research work on FBMs has primarily been conducted using a naturalistic approach in order to explore the role of the emotional and reconstructive factors on FBM formation and maintenance. Nevertheless, these studies lack a sufficient control on the factors that might intervene in the process of FBM formation. The contribution of the present studies is addressed to experimentally investigating the role of emotional and reconstructive factors on emotionally charged memories, specifically on FBMs. Paralleling FBM findings, the two studies revealed that simply being in an emotional state allows people to remember all available information, such as irrelevant and unrelated details. Furthermore, the resulting memories are affected by reconstructive processes so that they are not as accurate as their richness of details would suggest.

A class Hierarchical, object-oriented approach to virtual memory management

Science.gov (United States)

Russo, Vincent F.; Campbell, Roy H.; Johnston, Gary M.

1989-01-01

The Choices family of operating systems exploits class hierarchies and object-oriented programming to facilitate the construction of customized operating systems for shared memory and networked multiprocessors. The software is being used in the Tapestry laboratory to study the performance of algorithms, mechanisms, and policies for parallel systems. Described here are the architectural design and class hierarchy of the Choices virtual memory management system. The software and hardware mechanisms and policies of a virtual memory system implement a memory hierarchy that exploits the trade-off between response times and storage capacities. In Choices, the notion of a memory hierarchy is captured by abstract classes. Concrete subclasses of those abstractions implement a virtual address space, segmentation, paging, physical memory management, secondary storage, and remote (that is, networked) storage. Captured in the notion of a memory hierarchy are classes that represent memory objects. These classes provide a storage mechanism that contains encapsulated data and have methods to read or write the memory object. Each of these classes provides specializations to represent the memory hierarchy.

Implications of psychosocial stress on memory formation in a typical male versus female student sample.

NARCIS (Netherlands)

Cornelisse, S.; van Stegeren, A.H.; Joëls, M.

2011-01-01

Stress is known to differentially modulate memory function. Memory can be impaired or strengthened by stress, depending on e.g. the memory type and phase under study, the emotional value of the learned information and the sex of the subjects. Here, we addressed the latter and investigated the impact

Destination Memory and Cognitive Theory of Mind in Alzheimer's Disease.

Science.gov (United States)

El Haj, Mohamad; Gély-Nargeot, Marie-Christine; Raffard, Stéphane

2015-01-01

Destination memory, or the ability to remember the destination to whom a piece of information was addressed, is found to be compromised in Alzheimer's disease (AD). Our paper investigated the relationship between destination memory and theory of mind in AD since both destination memory and theory of mind are social abilities that require processing attributes of interlocutors. Mild AD participants and controls were administered tasks tapping destination memory, affective theory of mind, and 1st and 2nd order cognitive theory of mind. Relative to controls, AD participants showed compromise in destination memory and 2nd order cognitive theory of mind, but preserved performance on affective and 1st order cognitive theory of mind. Significant correlations were observed between destination memory, and 1st and 2nd order cognitive theory of mind in AD participants and controls. By demonstrating a relationship between compromises in 2nd order theory of mind and in destination memory, our work highlights links between social cognition and memory functioning in AD.

Understanding Organizational Memory from the Integrated Management Systems (ERP

Directory of Open Access Journals (Sweden)

Gilberto Perez

2013-10-01

Full Text Available With this research, in the form of a theoretical essay addressing the theme of Organizational Memory and Integrated Management Systems (ERP, we tried to present some evidence of how this type of system can contribute to the consolidation of certain features of Organizational Memory. From a theoretical review of the concepts of Human Memory, extending to the Organizational Memory and Information Systems, with emphasis on Integrated Management Systems (ERP we tried to draw a parallel between the functions and structures of Organizational Memory and features and characteristics of ERPs. The choice of the ERP system for this study was made due to the complexity and broad scope of this system. It was verified that the ERPs adequately support many functions of the Organizational Memory, highlighting the implementation of logical processes, practices and rules in business. It is hoped that the dialogue presented here can contribute to the advancement of the understanding of organizational memory, since the similarity of Human Memory is a fertile field and there is still much to be researched.

Reconsolidation of memory: a decade of debate.

Science.gov (United States)

Besnard, Antoine; Caboche, Jocelyne; Laroche, Serge

2012-10-01

Memory consolidation refers to a slow process that stabilises a memory trace after initial acquisition of novel events. The consolidation theory posits that once a memory is stored in the brain, it remains fixed for the lifetime of the memory. However, compelling evidence has suggested that upon recall, memories can re-enter a state of transient instability, requiring further stabilisation to be available once again for recall. Since its rehabilitation in the past ten years, this process of reconsolidation of memory after recall stimulated intense debates in the field of cognitive neuroscience. In this review we compile this plentiful literature with a particular emphasis on some of the key questions that have emerged from the reconsolidation theory. We focus on tracing the characterisation of the boundary conditions that constrain the occurrence of memory reconsolidation. We also discuss accumulating evidence supporting the idea that reconsolidation, as implied by its definition, is not a mere repetition of consolidation. We review seminal studies that uncovered specific mechanisms recruited during reconsolidation that are not always crucially involved in consolidation. We next address the physiological significance of reconsolidation since several lines of evidence support the idea that reconsolidation, as opposed to consolidation, may offer a unique opportunity to update memories. We finally discuss recent evidence for or against the potential that the process of memory reconsolidation offers for ongoing efforts to develop novel strategies to combat pathogenic memories. Copyright © 2012 Elsevier Ltd. All rights reserved.

Memory Reduction via Delayed Simulation

Directory of Open Access Journals (Sweden)

Michael Holtmann

2011-02-01

Full Text Available We address a central (and classical issue in the theory of infinite games: the reduction of the memory size that is needed to implement winning strategies in regular infinite games (i.e., controllers that ensure correct behavior against actions of the environment, when the specification is a regular omega-language. We propose an approach which attacks this problem before the construction of a strategy, by first reducing the game graph that is obtained from the specification. For the cases of specifications represented by "request-response"-requirements and general "fairness" conditions, we show that an exponential gain in the size of memory is possible.

Phonological Short-Term Memory, Working Memory and Foreign Language Performance in Intensive Language Learning

Science.gov (United States)

Kormos, Judit; Safar, Anna

2008-01-01

In our research we addressed the question what the relationship is between phonological short-term and working memory capacity and performance in an end-of-year reading, writing, listening, speaking and use of English test. The participants of our study were 121 secondary school students aged 15-16 in the first intensive language training year of…

Multi-Voxel Decoding and the Topography of Maintained Information During Visual Working Memory.

Science.gov (United States)

Lee, Sue-Hyun; Baker, Chris I

2016-01-01

The ability to maintain representations in the absence of external sensory stimulation, such as in working memory, is critical for guiding human behavior. Human functional brain imaging studies suggest that visual working memory can recruit a network of brain regions from visual to parietal to prefrontal cortex. In this review, we focus on the maintenance of representations during visual working memory and discuss factors determining the topography of those representations. In particular, we review recent studies employing multi-voxel pattern analysis (MVPA) that demonstrate decoding of the maintained content in visual cortex, providing support for a "sensory recruitment" model of visual working memory. However, there is some evidence that maintained content can also be decoded in areas outside of visual cortex, including parietal and frontal cortex. We suggest that the ability to maintain representations during working memory is a general property of cortex, not restricted to specific areas, and argue that it is important to consider the nature of the information that must be maintained. Such information-content is critically determined by the task and the recruitment of specific regions during visual working memory will be both task- and stimulus-dependent. Thus, the common finding of maintained information in visual, but not parietal or prefrontal, cortex may be more of a reflection of the need to maintain specific types of visual information and not of a privileged role of visual cortex in maintenance.

Multi-voxel decoding and the topography of maintained information during visual working memory

Directory of Open Access Journals (Sweden)

Sue-Hyun eLee

2016-02-01

Full Text Available The ability to maintain representations in the absence of external sensory stimulation, such as in working memory, is critical for guiding human behavior. Human functional brain imaging studies suggest that visual working memory can recruit a network of brain regions from visual to parietal to prefrontal cortex. In this review, we focus on the maintenance of representations during visual working memory and discuss factors determining the topography of those representations. In particular, we review recent studies employing multi-voxel pattern analysis that demonstrate decoding of the maintained content in visual cortex, providing support for a ‘sensory recruitment’ model of visual working memory. However, there is some evidence that maintained content can also be decoded in areas outside of visual cortex, including parietal and frontal cortex. We suggest that the ability to maintain representations during working memory is a general property of cortex, not restricted to specific areas, and argue that it is important to consider the nature of the information that must be maintained. Such information-content is critically determined by the task and the recruitment of specific regions during visual working memory will be both task- and stimulus-dependent. Thus, the common finding of maintained information in visual, but not parietal or prefrontal, cortex may be more of a reflection of the need to maintain specific types of visual information and not of a privileged role of visual cortex in maintenance.

Long-term semantic representations moderate the effect of attentional refreshing on episodic memory.

Science.gov (United States)

Loaiza, Vanessa M; Duperreault, Kayla A; Rhodes, Matthew G; McCabe, David P

2015-02-01

The McCabe effect (McCabe, Journal of Memory and Language 58:480-494, 2008) refers to an advantage in episodic memory (EM) retrieval for memoranda studied in complex span versus simple span tasks, particularly for memoranda presented in earlier serial positions. This finding has been attributed to the necessity to refresh memoranda during complex span tasks that, in turn, promotes content-context binding in working memory (WM). Several frameworks have conceptualized WM as being embedded in long-term memory. Thus, refreshing may be less efficient when memoranda are not well-established in long-term semantic memory (SM). To investigate this, we presented words and nonwords in simple and complex span trials in order to manipulate the long-term semantic representations of the memoranda with the requirement to refresh the memoranda during WM. A recognition test was administered that required participants to make a remember-know decision for each memorandum recognized as old. The results replicated the McCabe effect, but only for words, and the beneficial effect of refreshing opportunities was exclusive to recollection. These results extend previous research by indicating that the predictive relationship between WM refreshing and long-term EM is specific to recollection and, furthermore, moderated by representations in long-term SM. This supports the predictions of WM frameworks that espouse the importance of refreshing in content-context binding, but also those that view WM as being an activated subset of and, therefore, constrained by the contents of long-term memory.

Multi-Voxel Decoding and the Topography of Maintained Information During Visual Working Memory

Science.gov (United States)

Lee, Sue-Hyun; Baker, Chris I.

2016-01-01

The ability to maintain representations in the absence of external sensory stimulation, such as in working memory, is critical for guiding human behavior. Human functional brain imaging studies suggest that visual working memory can recruit a network of brain regions from visual to parietal to prefrontal cortex. In this review, we focus on the maintenance of representations during visual working memory and discuss factors determining the topography of those representations. In particular, we review recent studies employing multi-voxel pattern analysis (MVPA) that demonstrate decoding of the maintained content in visual cortex, providing support for a “sensory recruitment” model of visual working memory. However, there is some evidence that maintained content can also be decoded in areas outside of visual cortex, including parietal and frontal cortex. We suggest that the ability to maintain representations during working memory is a general property of cortex, not restricted to specific areas, and argue that it is important to consider the nature of the information that must be maintained. Such information-content is critically determined by the task and the recruitment of specific regions during visual working memory will be both task- and stimulus-dependent. Thus, the common finding of maintained information in visual, but not parietal or prefrontal, cortex may be more of a reflection of the need to maintain specific types of visual information and not of a privileged role of visual cortex in maintenance. PMID:26912997

FTK AMchip05: an Associative Memory Chip Prototype for Track Reconstruction at Hadron Collider Experiments

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00030662; The ATLAS collaboration; Annovi, Alberto; Beretta, Matteo; Beccherle, Roberto; Giannetti, Paola; Citraro, Saverio; Liberali, Valentino; Luciano, Pierluigi; Rossi, Enrico; Stabile, Alberto; Mirzaei, Mohammad Ali; Piadyk, Yurii

2015-01-01

The ATLAS FTK track trigger project is an upcoming upgrade for the ATLAS trigger system currently under installation. A first reduced-coverage FTK is expected to take data by the end of 2015, while full detector coverage will be reached in 2016 and more processing power will be added in 2017-2018. The ATLAS FTK is a dedicated supercomputing processor based on FPGAs and a custom ASIC: the Associative Memory chip (AMchip). The AMchip is the core processor in charge of the real-time pattern recognition stage of the FTK algorithm. It is based on Content Addressable Memory elements connected by advanced computation logic that adds the unique feature to look for correlated data patterns (e.g. tracks made of hits) within a sparse data set (e.g. hits of an event) processing data at the full I/O speed. The AMchip05 is the latest AMchip prototype before the final FTK production. It is functionally identical to the upcoming production chip with the only difference of pattern capacity. We will show the AMchip05 architect...

The working memory networks of the human brain.

Science.gov (United States)

Linden, David E J

2007-06-01

Working memory and short-term memory are closely related in their cognitive architecture, capacity limitations, and functional neuroanatomy, which only partly overlap with those of long-term memory. The author reviews the functional neuroimaging literature on the commonalities and differences between working memory and short-term memory and the interplay of areas with modality-specific and supramodal representations in the brain networks supporting these fundamental cognitive processes. Sensory stores in the visual, auditory, and somatosensory cortex play a role in short-term memory, but supramodal parietal and frontal areas are often recruited as well. Classical working memory operations such as manipulation, protection against interference, or updating almost certainly require at least some degree of prefrontal support, but many pure maintenance tasks involve these areas as well. Although it seems that activity shifts from more posterior regions during encoding to more anterior regions during delay, some studies reported sustained delay activity in sensory areas as well. This spatiotemporal complexity of the short-term memory/working memory networks is mirrored in the activation patterns that may explain capacity constraints, which, although most prominent in the parietal cortex, seem to be pervasive across sensory and premotor areas. Finally, the author highlights open questions for cognitive neuroscience research of working memory, such as that of the mechanisms for integrating different types of content (binding) or those providing the link to long-term memory.

Imagery Rescripting: The Impact of Conceptual and Perceptual Changes on Aversive Autobiographical Memories.

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Christien Slofstra

Full Text Available Imagery rescripting (ImRs is a process by which aversive autobiographical memories are rendered less unpleasant or emotional. ImRs is thought only to be effective if a change in the meaning-relevant (semantic content of the mental image is produced, according to a cognitive hypothesis of ImRs. We propose an additional hypothesis: that ImRs can also be effective by the manipulation of perceptual features of the memory, without explicitly targeting meaning-relevant content.In two experiments using a within-subjects design (both N = 48, community samples, both Conceptual-ImRs-focusing on changing meaning-relevant content-and Perceptual-ImRs-focusing on changing perceptual features-were compared to Recall-only of aversive autobiographical image-based memories. An active control condition, Recall + Attentional Breathing (Recall+AB was added in the first experiment. In the second experiment, a Positive-ImRs condition was added-changing the aversive image into a positive image that was unrelated to the aversive autobiographical memory. Effects on the aversive memory's unpleasantness, vividness and emotionality were investigated.In Experiment 1, compared to Recall-only, both Conceptual-ImRs and Perceptual-ImRs led to greater decreases in unpleasantness, and Perceptual-ImRs led to greater decreases in emotionality of memories. In Experiment 2, the effects on unpleasantness were not replicated, and both Conceptual-ImRs and Perceptual-ImRs led to greater decreases in emotionality, compared to Recall-only, as did Positive-ImRs. There were no effects on vividness, and the ImRs conditions did not differ significantly from Recall+AB.Results suggest that, in addition to traditional forms of ImRs, targeting the meaning-relevant content of an image during ImRs, relatively simple techniques focusing on perceptual aspects or positive imagery might also yield benefits. Findings require replication and extension to clinical samples.

Imagery Rescripting: The Impact of Conceptual and Perceptual Changes on Aversive Autobiographical Memories.

Science.gov (United States)

Slofstra, Christien; Nauta, Maaike H; Holmes, Emily A; Bockting, Claudi L H

2016-01-01

Imagery rescripting (ImRs) is a process by which aversive autobiographical memories are rendered less unpleasant or emotional. ImRs is thought only to be effective if a change in the meaning-relevant (semantic) content of the mental image is produced, according to a cognitive hypothesis of ImRs. We propose an additional hypothesis: that ImRs can also be effective by the manipulation of perceptual features of the memory, without explicitly targeting meaning-relevant content. In two experiments using a within-subjects design (both N = 48, community samples), both Conceptual-ImRs-focusing on changing meaning-relevant content-and Perceptual-ImRs-focusing on changing perceptual features-were compared to Recall-only of aversive autobiographical image-based memories. An active control condition, Recall + Attentional Breathing (Recall+AB) was added in the first experiment. In the second experiment, a Positive-ImRs condition was added-changing the aversive image into a positive image that was unrelated to the aversive autobiographical memory. Effects on the aversive memory's unpleasantness, vividness and emotionality were investigated. In Experiment 1, compared to Recall-only, both Conceptual-ImRs and Perceptual-ImRs led to greater decreases in unpleasantness, and Perceptual-ImRs led to greater decreases in emotionality of memories. In Experiment 2, the effects on unpleasantness were not replicated, and both Conceptual-ImRs and Perceptual-ImRs led to greater decreases in emotionality, compared to Recall-only, as did Positive-ImRs. There were no effects on vividness, and the ImRs conditions did not differ significantly from Recall+AB. Results suggest that, in addition to traditional forms of ImRs, targeting the meaning-relevant content of an image during ImRs, relatively simple techniques focusing on perceptual aspects or positive imagery might also yield benefits. Findings require replication and extension to clinical samples.

Influence of alloying elements on the corrosion properties of shape memory stainless steels

International Nuclear Information System (INIS)

Della Rovere, C.A.; Alano, J.H.; Silva, R.; Nascente, P.A.P.; Otubo, J.; Kuri, S.E.

2012-01-01

Highlights: ► The corrosion properties of three Fe–Mn–Si–Cr–Ni–(Co) shape-memory stainless steels (SMSSs) were compared with those of a type 304 (SS 304) austenitic stainless steel. ► A considerably high Si content (about 40 at%) is present in the anodic passive films formed on SMSSs in 0.5 M H 2 SO 4 solution. ► The high protectiveness of the anodic passive film formed on SMSSs in 0.5 M H 2 SO 4 solution results from a protective film consisting of a (Fe, Cr)–mixed silicate. ► The SMSSs exhibited higher corrosion resistance than SS 304 in highly oxidizing environments. ► The SMSSs showed poor corrosion resistance in 3.5% NaCl solution compared to that of SS 304. - Abstract: The corrosion properties of three Fe–Mn–Si–Cr–Ni–(Co) shape memory stainless steels were studied based on X-ray photoelectron spectroscopy (XPS) analyses, immersion and polarization tests. The test results were compared with those of a type 304 austenitic stainless steel. The XPS analyses indicated substantial Si content in the anodic passive films formed on shape memory stainless steels in sulfuric acid solution and that the high protectiveness of these films results from a protective film consisting of a (iron, chromium)–mixed silicate. The corrosion rate of the shape memory stainless steels in boiling nitric acid solution was lower than that of austenitic stainless steel. The high silicon content was found to play an important role in the corrosion behavior of these shape memory alloys in highly oxidizing environments. Due to their high manganese content, the shape memory stainless steels showed poor corrosion behavior in 3.5% sodium chloride solution when compared with austenitic stainless steel.

Frequency and Severity of Semantic Deficits in a Consecutive Memory Clinic Cohort

DEFF Research Database (Denmark)

Vogel, Asmus; Johannsen, Peter; Stokholm, Jette

2014-01-01

Background/Aim: Semantic memory deficits have been shown in dementia and mild cognitive impairment (MCI) by group comparisons. The aim of this study is to investigate the frequency of impairments on tests with semantic content in patients with dementia, MCI (amnestic and non-amnestic) and affective......). However, patients with affective disorders also had mild impairments on tests tapping semantic memory (25% were impaired on the most sensitive tests). Impairments on the Famous faces test were more frequently found in dementia and MCI as compared to patients with affective disorders. Conclusion: Short...... tests with semantic memory content are sensitive to changes in dementia and MCI, but impairments on such tests may also be found in other diseases, e.g. affective disorders. © 2014 S. Karger AG, Basel....

Low power and reliable SRAM memory cell and array design

CERN Document Server

Ishibashi, Koichiro

2011-01-01

Success in the development of recent advanced semiconductor device technologies is due to the success of SRAM memory cells. This book addresses various issues for designing SRAM memory cells for advanced CMOS technology. To study LSI design, SRAM cell design is the best materials subject because issues about variability, leakage and reliability have to be taken into account for the design.

Visual Working Memory Enhances the Neural Response to Matching Visual Input.

Science.gov (United States)

Gayet, Surya; Guggenmos, Matthias; Christophel, Thomas B; Haynes, John-Dylan; Paffen, Chris L E; Van der Stigchel, Stefan; Sterzer, Philipp

2017-07-12

Visual working memory (VWM) is used to maintain visual information available for subsequent goal-directed behavior. The content of VWM has been shown to affect the behavioral response to concurrent visual input, suggesting that visual representations originating from VWM and from sensory input draw upon a shared neural substrate (i.e., a sensory recruitment stance on VWM storage). Here, we hypothesized that visual information maintained in VWM would enhance the neural response to concurrent visual input that matches the content of VWM. To test this hypothesis, we measured fMRI BOLD responses to task-irrelevant stimuli acquired from 15 human participants (three males) performing a concurrent delayed match-to-sample task. In this task, observers were sequentially presented with two shape stimuli and a retro-cue indicating which of the two shapes should be memorized for subsequent recognition. During the retention interval, a task-irrelevant shape (the probe) was briefly presented in the peripheral visual field, which could either match or mismatch the shape category of the memorized stimulus. We show that this probe stimulus elicited a stronger BOLD response, and allowed for increased shape-classification performance, when it matched rather than mismatched the concurrently memorized content, despite identical visual stimulation. Our results demonstrate that VWM enhances the neural response to concurrent visual input in a content-specific way. This finding is consistent with the view that neural populations involved in sensory processing are recruited for VWM storage, and it provides a common explanation for a plethora of behavioral studies in which VWM-matching visual input elicits a stronger behavioral and perceptual response. SIGNIFICANCE STATEMENT Humans heavily rely on visual information to interact with their environment and frequently must memorize such information for later use. Visual working memory allows for maintaining such visual information in the mind

Visual working memory and threat monitoring: Spider fearfuls show disorder-specific change detection

NARCIS (Netherlands)

Reinecke, A.; Becker, E.S.; Rinck, M.

2010-01-01

Previous studies of biased information processing in anxiety addressed biases of attention and memory, but little is known about the processes taking place between them: visual working memory (VWM) and monitoring of threat. We investigated these processes with a change detection paradigm. In

Erasing and blurring memories: The differential impact of interference on separate aspects of forgetting.

Science.gov (United States)

Sun, Sol Z; Fidalgo, Celia; Barense, Morgan D; Lee, Andy C H; Cant, Jonathan S; Ferber, Susanne

2017-11-01

Interference disrupts information processing across many timescales, from immediate perception to memory over short and long durations. The widely held similarity assumption states that as similarity between interfering information and memory contents increases, so too does the degree of impairment. However, information is lost from memory in different ways. For instance, studied content might be erased in an all-or-nothing manner. Alternatively, information may be retained but the precision might be degraded or blurred. Here, we asked whether the similarity of interfering information to memory contents might differentially impact these 2 aspects of forgetting. Observers studied colored images of real-world objects, each followed by a stream of interfering objects. Across 4 experiments, we manipulated the similarity between the studied object and the interfering objects in circular color space. After interference, memory for object color was tested continuously on a color wheel, which in combination with mixture modeling, allowed for estimation of how erasing and blurring differentially contribute to forgetting. In contrast to the similarity assumption, we show that highly dissimilar interfering items caused the greatest increase in random guess responses, suggesting a greater frequency of memory erasure (Experiments 1-3). Moreover, we found that observers were generally able to resist interference from highly similar items, perhaps through surround suppression (Experiments 1 and 4). Finally, we report that interference from items of intermediate similarity tended to blur or decrease memory precision (Experiments 3 and 4). These results reveal that the nature of visual similarity can differentially alter how information is lost from memory. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Use of non-volatile memories for SSC detector readout

International Nuclear Information System (INIS)

Fennelly, A.J.; Woosley, J.K.; Johnson, M.B.

1990-01-01

Use of non-volatile memory units at the end of each fiber optic bunch/strand would substantially increase information available from experiments by providing a complete event history, in addition to easing real time processing requirements. This may be an alternative to enhancing technology to optical computing techniques. Available and low-risk projected technologies will be surveyed, with costing addressed. Some discussion will be given to covnersion of optical signals, to electronic information, concepts for providing timing pulses to the memory units, and to the magnetoresistive (MRAM) and ferroelectric (FERAM) random access memory technologies that may be utilized in the prototype system

Caffeine effects on mood and memory.

Science.gov (United States)

Herz, R S

1999-09-01

The purpose of the present research was to assess whether a psychoactive dose of caffeine would have differential affects on the mood dimensions of arousal versus feelings of pleasantness and whether these mood alterations would influence memory either by (1) the experience of arousal at learning and/or (2) altered and congruent mood states at learning and recall. To address these questions, the administration of 5 mg/kg caffeine or placebo at learning and retrieval sessions was manipulated and subjects' mood was evaluated by several different self-report measures. Sixteen words were incidentally studied during the learning session and memory was evaluated by the number of words correctly recalled at the retrieval session two days later. Results revealed that caffeine reliably increased arousal, but did not affect any emotion dimensions related to feelings of pleasure. Subjects who received caffeine at learning and retrieval were also in equivalent mood states at both sessions. Moreover, caffeine did not produce any effects on memory; thus, neither hypothesis concerning the influence of arousal on memory was supported. These data show that caffeine is a useful method for manipulating arousal in the laboratory without influencing feelings of pleasantness or learning and memory performance.

A Preisach type model for temperature driven hysteresis memory erasure in shape memory materials

Czech Academy of Sciences Publication Activity Database

Kopfová, J.; Krejčí, Pavel

2011-01-01

Roč. 23, č. 2 (2011), s. 125-137 ISSN 0935-1175 R&D Projects: GA ČR GAP201/10/2315 Institutional research plan: CEZ:AV0Z10190503 Keywords : shape memory * hysteresis * thermodynamical consistency * uniform convergence Subject RIV: BA - General Mathematics Impact factor: 1.310, year: 2011 http://www.springerlink.com/content/6325635691ku0477/

Impurity and quaternions in nonrelativistic scattering from a quantum memory

International Nuclear Information System (INIS)

Margetis, Dionisios; Grillakis, Manoussos G

2008-01-01

Models of quantum computing rely on transformations of the states of a quantum memory. We study mathematical aspects of a model proposed by Wu in which the memory state is changed via the scattering of incoming particles. This operation causes the memory content to deviate from a pure state, i.e. induces impurity. For nonrelativistic particles scattered from a two-state memory and sufficiently general interaction potentials in (1+1) dimensions, we express impurity in terms of quaternionic commutators. In this context, pure memory states correspond to null hyperbolic quaternions. In the case with point interactions, the scattering process amounts to appropriate rotations of quaternions in the frequency domain. Our work complements previous analyses by Margetis and Myers (2006 J. Phys. A 39 11567)

Ductile shape memory alloys of the Cu-Al-Mn system

International Nuclear Information System (INIS)

Kainuma, R.; Takahashi, S.; Ishida, K.

1995-01-01

Cu-Al-Mn shape memory alloys with enhanced ductility have been developed by decreasing the degree of order in the β parent phase. Cu-Al-Mn alloys with Al contents lower than 18% exhibit good ductility with elongations of about 15% and excellent cold-workability arising from a lower degree of order in the Heusler (L21) β 1 parent phase, without any loss in their shape memory behavior. In this paper the mechanical and shape memory characteristics, such as the cold-workability, the Ms temperatures, the shape memory effect and the pseudo-elasticity of such ductile Cu-Al-Mn alloys are presented. (orig.)