Science.gov

Sample records for gating memory related

  1. Multiple gates on working memory

    PubMed Central

    Chatham, Christopher H; Badre, David

    2015-01-01

    The contexts for action may be only transiently visible, accessible, and relevant. The corticobasal ganglia (BG) circuit addresses these demands by allowing the right motor plans to drive action at the right times, via a BG-mediated gate on motor representations. A long-standing hypothesis posits these same circuits are replicated in more rostral brain regions to support gating of cognitive representations. Key evidence now supports the prediction that BG can act as a gate on the input to working memory, as a gate on its output, and as a means of reallocating working memory representations rendered irrelevant by recent events. These discoveries validate key tenets of many computational models, circumscribe motor and cognitive models of recurrent cortical dynamics alone, and identify novel directions for research on the mechanisms of higher-level cognition. PMID:26719851

  2. MEMORIAL WALK WITH MEMORIALS, TOWARD ENTRANCE GATE. VIEW TO WEST. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    MEMORIAL WALK WITH MEMORIALS, TOWARD ENTRANCE GATE. VIEW TO WEST. - Rock Island National Cemetery, Rock Island Arsenal, 0.25 mile north of southern tip of Rock Island, Rock Island, Rock Island County, IL

  3. ENTRANCE GATE AND MEMORIAL AVENUE APPROACH, LOOKING INTO CEMETERY WITH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    ENTRANCE GATE AND MEMORIAL AVENUE APPROACH, LOOKING INTO CEMETERY WITH ADMINISTRATION BUILDING IN BACKGROUND. VIEW TO NORTHWEST. - Mountain Home National Cemetery, Mountain Home, Washington County, TN

  4. Radiation Issues and Applications of Floating Gate Memories

    NASA Technical Reports Server (NTRS)

    Scheick, L. Z.; Nguyen, D. N.

    2000-01-01

    The radiation effects that affect various systems that comprise floating gate memories are presented. The wear-out degradation results of unirradiated flash memories are compared to irradiated flash memories. The procedure analyzes the failure to write and erase caused by wear-out and degradation of internal charge pump circuits. A method is described for characterizing the radiation effects of the floating gate itself. The rate dependence, stopping power dependence, SEU susceptibility and applications of floating gate in radiation environment are presented. The ramifications for dosimetry and cell failure are discussed as well as for the long term use aspects of non-volatile memories.

  5. Stacked-Gate FET's For Analog Memory Elements

    NASA Technical Reports Server (NTRS)

    Thakoor, Anilkumar P.; Moopenn, Alexander W.

    1991-01-01

    Three-terminal, double-stacked-gate field-effect transistor (FET), developed as analog memory element. Particularly suited for use as synapse with variable connection strength in electronic neural network. Provides programmable, nonvolatile resistive connection, somewhat in manner of porous-gate FET described in "Porous-Floating-Gate Field-Effect Transistor" (NPO-17532). Resembles commercial erasable programmable read-only memory (EPROM) device, except for thickness of layers of silicon dioxide electrically isolating gates. Either p-channel or n-channel device.

  6. GETTYSBURG ADDRESS TABLET BESIDE ENTRANCE GATE AT MEMORIAL WALK. VIEW ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    GETTYSBURG ADDRESS TABLET BESIDE ENTRANCE GATE AT MEMORIAL WALK. VIEW TO EAST. - Rock Island National Cemetery, Rock Island Arsenal, 0.25 mile north of southern tip of Rock Island, Rock Island, Rock Island County, IL

  7. DETAIL OF FENCE FLANKING GATE AT ENTRANCE TO MEMORIAL WALK. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL OF FENCE FLANKING GATE AT ENTRANCE TO MEMORIAL WALK. VIEW TO NORTHEAST. - Rock Island National Cemetery, Rock Island Arsenal, 0.25 mile north of southern tip of Rock Island, Rock Island, Rock Island County, IL

  8. GATE AND FLANKING FENCE AT ENTRANCE TO MEMORIAL WALK. VIEW ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    GATE AND FLANKING FENCE AT ENTRANCE TO MEMORIAL WALK. VIEW TO NORTHEAST. - Rock Island National Cemetery, Rock Island Arsenal, 0.25 mile north of southern tip of Rock Island, Rock Island, Rock Island County, IL

  9. Improved Reading Gate For Vertical-Bloch-Line Memory

    NASA Technical Reports Server (NTRS)

    Wu, Jiin-Chuan; Stadler, Henry L.; Katti, Romney R.

    1994-01-01

    Improved design for reading gate of vertical-Bloch-line magnetic-bubble memory increases reliability of discrimination between binary ones and zeros. Magnetic bubbles that signify binary "1" and "0" produced by applying sufficiently large chopping currents to memory stripes. Bubbles then propagated differentially in bubble sorter. Method of discriminating between ones and zeros more reliable.

  10. Organic nano-floating-gate transistor memory with metal nanoparticles

    NASA Astrophysics Data System (ADS)

    Van Tho, Luu; Baeg, Kang-Jun; Noh, Yong-Young

    2016-04-01

    Organic non-volatile memory is advanced topics for various soft electronics applications as lightweight, low-cost, flexible, and printable solid-state data storage media. As a key building block, organic field-effect transistors (OFETs) with a nano-floating gate are widely used and promising structures to store digital information stably in a memory cell. Different types of nano-floating-gates and their various synthesis methods have been developed and applied to fabricate nanoparticle-based non-volatile memory devices. In this review, recent advances in the classes of nano-floating-gate OFET memory devices using metal nanoparticles as charge-trapping sites are briefly reviewed. Details of device fabrication, characterization, and operation mechanisms are reported based on recent research activities reported in the literature.

  11. Configurable Unitary Transformations and Linear Logic Gates Using Quantum Memories

    NASA Astrophysics Data System (ADS)

    Campbell, G. T.; Pinel, O.; Hosseini, M.; Ralph, T. C.; Buchler, B. C.; Lam, P. K.

    2014-08-01

    We show that a set of optical memories can act as a configurable linear optical network operating on frequency-multiplexed optical states. Our protocol is applicable to any quantum memories that employ off-resonant Raman transitions to store optical information in atomic spins. In addition to the configurability, the protocol also offers favorable scaling with an increasing number of modes where N memories can be configured to implement arbitrary N-mode unitary operations during storage and readout. We demonstrate the versatility of this protocol by showing an example where cascaded memories are used to implement a conditional cz gate.

  12. Solution processed molecular floating gate for flexible flash memories.

    PubMed

    Zhou, Ye; Han, Su-Ting; Yan, Yan; Huang, Long-Biao; Zhou, Li; Huang, Jing; Roy, V A L

    2013-01-01

    Solution processed fullerene (C60) molecular floating gate layer has been employed in low voltage nonvolatile memory device on flexible substrates. We systematically studied the charge trapping mechanism of the fullerene floating gate for both p-type pentacene and n-type copper hexadecafluorophthalocyanine (F16CuPc) semiconductor in a transistor based flash memory architecture. The devices based on pentacene as semiconductor exhibited both hole and electron trapping ability, whereas devices with F16CuPc trapped electrons alone due to abundant electron density. All the devices exhibited large memory window, long charge retention time, good endurance property and excellent flexibility. The obtained results have great potential for application in large area flexible electronic devices. PMID:24172758

  13. Solution processed molecular floating gate for flexible flash memories

    PubMed Central

    Zhou, Ye; Han, Su-Ting; Yan, Yan; Huang, Long-Biao; Zhou, Li; Huang, Jing; Roy, V. A. L.

    2013-01-01

    Solution processed fullerene (C60) molecular floating gate layer has been employed in low voltage nonvolatile memory device on flexible substrates. We systematically studied the charge trapping mechanism of the fullerene floating gate for both p-type pentacene and n-type copper hexadecafluorophthalocyanine (F16CuPc) semiconductor in a transistor based flash memory architecture. The devices based on pentacene as semiconductor exhibited both hole and electron trapping ability, whereas devices with F16CuPc trapped electrons alone due to abundant electron density. All the devices exhibited large memory window, long charge retention time, good endurance property and excellent flexibility. The obtained results have great potential for application in large area flexible electronic devices. PMID:24172758

  14. Experimental study of three-dimensional fin-channel charge trapping flash memories with titanium nitride and polycrystalline silicon gates

    NASA Astrophysics Data System (ADS)

    Liu, Yongxun; Matsukawa, Takashi; Endo, Kazuhiko; O'uchi, Shinichi; Tsukada, Junichi; Yamauchi, Hiromi; Ishikawa, Yuki; Mizubayashi, Wataru; Morita, Yukinori; Migita, Shinji; Ota, Hiroyuki; Masahara, Meishoku

    2014-01-01

    Three-dimensional (3D) fin-channel charge trapping (CT) flash memories with different gate materials of physical-vapor-deposited (PVD) titanium nitride (TiN) and n+-polycrystalline silicon (poly-Si) have successfully been fabricated by using (100)-oriented silicon-on-insulator (SOI) wafers and orientation-dependent wet etching. Electrical characteristics of the fabricated flash memories including statistical threshold voltage (Vt) variability, endurance, and data retention have been comparatively investigated. It was experimentally found that a larger memory window and a deeper erase are obtained in PVD-TiN-gated metal-oxide-nitride-oxide-silicon (MONOS)-type flash memories than in poly-Si-gated poly-Si-oxide-nitride-oxide-silicon (SONOS)-type memories. The larger memory window and deeper erase of MONOS-type flash memories are contributed by the higher work function of the PVD-TiN metal gate than of the n+-poly-Si gate, which is effective for suppressing electron back tunneling during erase operation. It was also found that the initial Vt roll-off due to the short-channel effect (SCE) is directly related to the memory window roll-off when the gate length (Lg) is scaled down to 46 nm or less.

  15. Learning to use working memory: a reinforcement learning gating model of rule acquisition in rats.

    PubMed

    Lloyd, Kevin; Becker, Nadine; Jones, Matthew W; Bogacz, Rafal

    2012-01-01

    Learning to form appropriate, task-relevant working memory representations is a complex process central to cognition. Gating models frame working memory as a collection of past observations and use reinforcement learning (RL) to solve the problem of when to update these observations. Investigation of how gating models relate to brain and behavior remains, however, at an early stage. The current study sought to explore the ability of simple RL gating models to replicate rule learning behavior in rats. Rats were trained in a maze-based spatial learning task that required animals to make trial-by-trial choices contingent upon their previous experience. Using an abstract version of this task, we tested the ability of two gating algorithms, one based on the Actor-Critic and the other on the State-Action-Reward-State-Action (SARSA) algorithm, to generate behavior consistent with the rats'. Both models produced rule-acquisition behavior consistent with the experimental data, though only the SARSA gating model mirrored faster learning following rule reversal. We also found that both gating models learned multiple strategies in solving the initial task, a property which highlights the multi-agent nature of such models and which is of importance in considering the neural basis of individual differences in behavior. PMID:23115551

  16. The split-gate flash memory with an extra select gate for automotive applications

    NASA Astrophysics Data System (ADS)

    Tsair, Yong-Shiuan; Fang, Yean-Kuen; Wang, Yu-Hsiung; Chu, Wen-Ting; Hsieh, Chia-Ta; Lin, Yung-Tao; Wang, Chung S.; Wong, Myron; Lee, Scott; Smolen, Richard; Liu, Bill

    2009-10-01

    In this paper, novel split-gate flash memory with an extra select gate (ESG) to improve the operation window has been investigated in details. Experimental results show that with the ESG (called 2.5T cell), the cell showed a better program wordline disturb window than that of the traditional split-gate flash memory cells (called 1.5T cell) around 0.5 V (at Vs = 10 V). The offset of minimum drain voltage to avoid punch through disturb between without and with wordline stress for 2.5T cell and 1.5T cell are around 0.05 V and 0.2 V, respectively. We attribute these improvements in wordline disturb behaviors to the reduction of channel leakage current with the addition of ESG. During the erase stage, the gate oxide of the ESG suffers free stress, thus having better oxide integrity to resist the generation of channel leakage current. In addition, the ESG offers a reverse bias to retard the leakage current from drain to source.

  17. Auto and hetero-associative memory using a 2-D optical logic gate

    NASA Technical Reports Server (NTRS)

    Chao, Tien-Hsin (Inventor)

    1992-01-01

    An optical system for auto-associative and hetero-associative recall utilizing Hamming distance as the similarity measure between a binary input image vector V(sup k) and a binary image vector V(sup m) in a first memory array using an optical Exclusive-OR gate for multiplication of each of a plurality of different binary image vectors in memory by the input image vector. After integrating the light of each product V(sup k) x V(sup m), a shortest Hamming distance detection electronics module determines which product has the lowest light intensity and emits a signal that activates a light emitting diode to illuminate a corresponding image vector in a second memory array for display. That corresponding image vector is identical to the memory image vector V(sup m) in the first memory array for auto-associative recall or related to it, such as by name, for hetero-associative recall.

  18. Numerical simulation study of organic nonvolatile memory with polysilicon floating gate

    NASA Astrophysics Data System (ADS)

    Zhao-wen, Yan; Jiao, Wang; Jian-li, Qiao; Wen-jie, Chen; Pan, Yang; Tong, Xiao; Jian-hong, Yang

    2016-06-01

    A polysilicon-based organic nonvolatile floating-gate memory device with a bottom-gate top-contact configuration is investigated, in which polysilicon is sandwiched between oxide layers as a floating gate. Simulations for the electrical characteristics of the polysilicon floating gate-based memory device are performed. The shifted transfer characteristics and corresponding charge trapping mechanisms during programing and erasing (P/E) operations at various P/E voltages are discussed. The simulated results show that present memory exhibits a large memory window of 57.5 V, and a high read current on/off ratio of ≈ 103. Compared with the reported experimental results, these simulated results indicate that the polysilicon floating gate based memory device demonstrates remarkable memory effects, which shows great promise in device designing and practical application.

  19. Memory effect in silicon time-gated single-photon avalanche diodes

    SciTech Connect

    Dalla Mora, A.; Contini, D. Di Sieno, L.; Tosi, A.; Boso, G.; Villa, F.; Pifferi, A.

    2015-03-21

    We present a comprehensive characterization of the memory effect arising in thin-junction silicon Single-Photon Avalanche Diodes (SPADs) when exposed to strong illumination. This partially unknown afterpulsing-like noise represents the main limiting factor when time-gated acquisitions are exploited to increase the measurement dynamic range of very fast (picosecond scale) and faint (single-photon) optical signals following a strong stray one. We report the dependences of this unwelcome signal-related noise on photon wavelength, detector temperature, and biasing conditions. Our results suggest that this so-called “memory effect” is generated in the deep regions of the detector, well below the depleted region, and its contribution on detector response is visible only when time-gated SPADs are exploited to reject a strong burst of photons.

  20. Floating gate memory-based monolayer MoS2 transistor with metal nanocrystals embedded in the gate dielectrics.

    PubMed

    Wang, Jingli; Zou, Xuming; Xiao, Xiangheng; Xu, Lei; Wang, Chunlan; Jiang, Changzhong; Ho, Johnny C; Wang, Ti; Li, Jinchai; Liao, Lei

    2015-01-14

    Charge trapping layers are formed from different metallic nanocrystals in MoS2 -based nanocrystal floating gate memory cells in a process compatible with existing fabrication technologies. The memory cells with Au nanocrystals exhibit impressive performance with a large memory window of 10 V, a high program/erase ratio of approximately 10(5) and a long retention time of 10 years. PMID:25115804

  1. Nonvolatile Quantum Dot Gate Memory (NVQDM): Tunneling Rate from Quantum Well Channel to Quantum Dot Gate

    NASA Astrophysics Data System (ADS)

    Hasaneen, El-Sayed; Heller, Evan; Bansal, Rajeev; Jain, Faquir

    2003-10-01

    In this paper, we compute the tunneling of electrons in a nonvolatile quantum dot memory (NVQDM) cell during the WRITE operation. The transition rate of electrons from a quantum well channel to the quantum dots forming the floating gate is calculated using a recently reported method by Chuang et al.[1]. Tunneling current is computed based on transport of electrons from the channel to the floating quantum dots. The maximum number of electrons on a dot is calculated using surface electric field and break down voltage of the tunneling dielectric material. Comparison of tunneling for silicon oxide and high-k dielectric gate insulators is also described. Capacitance-Voltage characteristics of a NVQDM device are calculated by solving the Schrodinger and Poisson equations self-consistently. In addition, the READ operation of the memory has been investigated analytically. Results for 70 nm channel length Si NVQDMs are presented. Threshold voltage is calculated including the effect of the charge on nanocrystal quantum dots. Current-voltage characteristics are obtained using BSIM3v3 model [2-3]. This work is supported by Office of Navel Research (N00014210883, Dr. D. Purdy, Program Monitor), Connecticut Innovations Inc./TranSwitch (CII # 00Y17), and National Science Foundation (CCR-0210428) grants. [1] S. L. Chuang and N. Holonyak, Appl. Phys. Lett., 80, pp. 1270, 2002. [2] Y. Chen et. al., BSIM3v3 Manual, Elect. Eng. and Comp. Dept., U. California, Berkeley, CA, 1996. [3] W. Liu, MOSFET Models for SPICE Simulation, John Wiley & Sons, Inc., 2001.

  2. Ambipolar organic thin-film transistor-based nano-floating-gate nonvolatile memory

    SciTech Connect

    Han, Jinhua; Wang, Wei Ying, Jun; Xie, Wenfa

    2014-01-06

    An ambipolar organic thin-film transistor-based nano-floating-gate nonvolatile memory was demonstrated, with discrete distributed gold nanoparticles, tetratetracontane (TTC), pentacene as the floating-gate layer, tunneling layer, and active layer, respectively. The electron traps at the TTC/pentacene interface were significantly suppressed, which resulted in an ambipolar operation in present memory. As both electrons and holes were supplied in the channel and trapped in the floating-gate by programming/erasing operations, respectively, i.e., one type of charge carriers was used to overwrite the other, trapped, one, a large memory window, extending on both sides of the initial threshold voltage, was realized.

  3. Organic field-effect transistor nonvolatile memories utilizing sputtered C nanoparticles as nano-floating-gate

    SciTech Connect

    Liu, Jie; Liu, Chang-Hai; She, Xiao-Jian; Sun, Qi-Jun; Gao, Xu; Wang, Sui-Dong

    2014-10-20

    High-performance organic field-effect transistor nonvolatile memories have been achieved using sputtered C nanoparticles as the nano-floating-gate. The sputtered C nano-floating-gate is prepared with low-cost material and simple process, forming uniform and discrete charge trapping sites covered by a smooth and complete polystyrene layer. The devices show large memory window, excellent retention capability, and programming/reading/erasing/reading endurance. The sputtered C nano-floating-gate can effectively trap both holes and electrons, and it is demonstrated to be suitable for not only p-type but also n-type organic field-effect transistor nonvolatile memories.

  4. Memory and learning behaviors mimicked in nanogranular SiO2-based proton conductor gated oxide-based synaptic transistors

    NASA Astrophysics Data System (ADS)

    Wan, Chang Jin; Zhu, Li Qiang; Zhou, Ju Mei; Shi, Yi; Wan, Qing

    2013-10-01

    In neuroscience, signal processing, memory and learning function are established in the brain by modifying ionic fluxes in neurons and synapses. Emulation of memory and learning behaviors of biological systems by nanoscale ionic/electronic devices is highly desirable for building neuromorphic systems or even artificial neural networks. Here, novel artificial synapses based on junctionless oxide-based protonic/electronic hybrid transistors gated by nanogranular phosphorus-doped SiO2-based proton-conducting films are fabricated on glass substrates by a room-temperature process. Short-term memory (STM) and long-term memory (LTM) are mimicked by tuning the pulse gate voltage amplitude. The LTM process in such an artificial synapse is due to the proton-related interfacial electrochemical reaction. Our results are highly desirable for building future neuromorphic systems or even artificial networks via electronic elements.In neuroscience, signal processing, memory and learning function are established in the brain by modifying ionic fluxes in neurons and synapses. Emulation of memory and learning behaviors of biological systems by nanoscale ionic/electronic devices is highly desirable for building neuromorphic systems or even artificial neural networks. Here, novel artificial synapses based on junctionless oxide-based protonic/electronic hybrid transistors gated by nanogranular phosphorus-doped SiO2-based proton-conducting films are fabricated on glass substrates by a room-temperature process. Short-term memory (STM) and long-term memory (LTM) are mimicked by tuning the pulse gate voltage amplitude. The LTM process in such an artificial synapse is due to the proton-related interfacial electrochemical reaction. Our results are highly desirable for building future neuromorphic systems or even artificial networks via electronic elements. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr02987e

  5. Determining the state of non-volatile memory cells with floating gate using scanning probe microscopy

    NASA Astrophysics Data System (ADS)

    Hanzii, D.; Kelm, E.; Luapunov, N.; Milovanov, R.; Molodcova, G.; Yanul, M.; Zubov, D.

    2013-01-01

    During a failure analysis of integrated circuits, containing non-volatile memory, it is often necessary to determine its contents while Standard memory reading procedures are not applicable. This article considers how the state of NVM cells with floating gate can be determined using scanning probe microscopy. Samples preparation and measuring procedure are described with the example of Microchip microcontrollers with the EPROM memory (PIC12C508) and flash-EEPROM memory (PIC16F876A).

  6. Effect of tunneling layers on the performances of floating-gate based organic thin-film transistor nonvolatile memories

    SciTech Connect

    Wang, Wei Han, Jinhua; Ying, Jun; Xiang, Lanyi; Xie, Wenfa

    2014-09-22

    Two types of floating-gate based organic thin-film transistor nonvolatile memories (FG-OTFT-NVMs) were demonstrated, with poly(methyl methacrylate co glycidyl methacrylate) (P(MMA-GMA)) and tetratetracontane (TTC) as the tunneling layer, respectively. Their device performances were measured and compared. In the memory with a P(MMA-GMA) tunneling layer, typical unipolar hole transport was obtained with a relatively small mobility of 0.16 cm{sup 2}/V s. The unidirectional shift of turn-on voltage (V{sub on}) due to only holes trapped/detrapped in/from the floating gate resulted in a small memory window of 12.5 V at programming/erasing voltages (V{sub P}/V{sub E}) of ±100 V and a nonzero reading voltage. Benefited from the well-ordered molecule orientation and the trap-free surface of TTC layer, a considerably high hole mobility of 1.7 cm{sup 2}/V s and a visible feature of electrons accumulated in channel and trapped in floating-gate were achieved in the memory with a TTC tunneling layer. High hole mobility resulted in a high on current and a large memory on/off ratio of 600 at the V{sub P}/V{sub E} of ±100 V. Both holes and electrons were injected into floating-gate and overwritten each other, which resulted in a bidirectional V{sub on} shift. As a result, an enlarged memory window of 28.6 V at the V{sub P}/V{sub E} of ±100 V and a zero reading voltage were achieved. Based on our results, a strategy is proposed to optimize FG-OTFT-NVMs by choosing a right tunneling layer to improve the majority carrier mobility and realize ambipolar carriers injecting and trapping in the floating-gate.

  7. Ambipolar nonvolatile memory based on a quantum-dot transistor with a nanoscale floating gate

    NASA Astrophysics Data System (ADS)

    Che, Yongli; Zhang, Yating; Cao, Xiaolong; Song, Xiaoxian; Cao, Mingxuan; Dai, Haitao; Yang, Junbo; Zhang, Guizhong; Yao, Jianquan

    2016-07-01

    Using only solution processing methods, we developed ambipolar quantum-dot (QD) transistor floating-gate memory (FGM) that uses Au nanoparticles as a floating gate. Because of the bipolarity of the active channel of PbSe QDs, the memory could easily trap holes or electrons in the floating gate by programming/erasing (P/E) operations, which could shift the threshold voltage both up and down. As a result, the memory exhibited good programmable memory characteristics: a large memory window (ΔVth ˜ 15 V) and a long retention time (>105 s). The magnitude of ΔVth depended on both P/E voltages and the bias voltage (VDS): ΔVth was a cubic function to VP/E and linearly depended on VDS. Therefore, this FGM based on a QD transistor is a promising alternative to its inorganic counterparts owing to its advantages of bipolarity, high mobility, low cost, and large-area production.

  8. MOSFET nonvolatile memory with a high-density tungsten nanodot floating gate formed by self-assembled nanodot deposition

    NASA Astrophysics Data System (ADS)

    Pei, Y.; Yin, C.; Bea, J. C.; Kino, H.; Fukushima, T.; Tanaka, T.; Koyanagi, M.

    2009-04-01

    Metal-oxide-semiconductor field-effect transistor (MOSFET) nonvolatile memories with high-density tungsten nanodots (W-NDs) dispersed in silicon nitride as a floating gate were fabricated and characterized. The W-NDs with a high density of ~5 × 1012 cm-2 and small sizes of 2-3 nm were formed by self-assembled nanodot deposition (SAND). A large memory window of ~1.7 V was observed with bi-directional gate voltage sweeping between -10 and +10 V. Considering that there is no hysteresis memory window for the reference sample without W-NDs, this result indicates the charge trapping in W-NDs or related defects. Finally, the program/erase speed and retention characteristics were investigated and discussed in this paper.

  9. Flash Memory Device with ‘I’ Shape Floating Gate for Sub-70 nm NAND Flash Memory

    NASA Astrophysics Data System (ADS)

    Jung, Sang-Goo; Lee, Jong-Ho

    2006-11-01

    In this article, we proposed a novel ‘I’ shape floating gate applicable to the sub-70 nm flash memory cell with high performance and scalability. It has modified floating gate of conventional flash memory to have high coupling-ratio (\\mathit{CR}), low effect of interference or cross-talk. Specifically, it has ˜13% higher \\mathit{CR} and ˜33/46% lower effect of cross-talk of the bit-line/word-line state than those of conventional flash memory cell with scale-downed geometry. In addition, ‘I’ shape flash memory cell shows improved characteristics about programming time, drain disturbance, read current, sub-threshold swing, and drain induced barrier lowering than conventional flash memory cell.

  10. Organic field-effect transistor nonvolatile memories based on hybrid nano-floating-gate

    NASA Astrophysics Data System (ADS)

    Gao, Xu; She, Xiao-Jian; Liu, Chang-Hai; Sun, Qi-Jun; Liu, Jie; Wang, Sui-Dong

    2013-01-01

    High performance organic field-effect transistor nonvolatile memory is achieved by integrating gold nanoparticles and graphene oxide sheets as the hybrid nano-floating-gate. The device shows a large memory window of about 40 V, high ON/OFF ratio of reading current over 104, excellent programming/erasing endurance, and retention ability. The hybrid nano-floating-gate can increase the density of charge trapping sites, which are electrically separate from each other and thus suppress the stored charge leakage. The memory window is increased under illumination, and the results indicate that the photon-generated carriers facilitate the electron trapping but have almost no effect on the hole trapping.

  11. Al2O3 nanocrystals embedded in amorphous Lu2O3 high-k gate dielectric for floating gate memory application

    NASA Astrophysics Data System (ADS)

    Yuan, C. L.; Chan, M. Y.; Lee, P. S.; Darmawan, P.; Setiawan, Y.

    2007-04-01

    The integration of nanoparticles has high potential in technological applications and opens up possibilities of the development of new devices. Compared to the conventional floating gate memory, a structure containing nanocrystals embedded in dielectrics shows high potential to produce a memory with high endurance, low operating voltage, fast write-erase speeds and better immunity to soft errors [S. Tiwari, F. Rana, H. Hanafi et al. 1996 Appl.Phys. Lett. 68, 1377]. A significant improvement on data retention [J. J. Lee, X. Wang et al. 2003 Proceedings of the VLSI Technol. Symposium, p33] can be observed when discrete nanodots are used instead of continuous floating gate as charge storage nodes because local defect related leakage can be reduced efficiently. Furthermore, using a high-k dielectric in place of the conventional SiO2 based dielectric, nanodots flash memory is able to achieve significantly improved programming efficiency and data retention [A. Thean and J. -P. Leburton, 2002 IEEE Potentials 21, 35; D. W. Kim, T. Kim and S. K. Banerjee, 2003 IEEE Trans. Electron Devices 50, 1823]. We have recently successfully developed a method to produce nanodots embedded in high-k gate dielectrics [C. L. Yuan, P. Darmawan, Y. Setiawan and P. S. Lee, 2006 Electrochemical and Solid-State Letters 9, F53; C. L. Yuan, P. Darmawan, Y. Setiawan and P. S. Lee, 2006 Europhys. Lett. 74, 177]. In this paper, we fabricated the memory structure of Al2O3 nanocrystals embedded in amorphous Lu2O3 high k dielectric using pulsed laser ablation. The mean size and density of the Al2O3 nanocrystals are estimated to be about 5 nm and 7x1011 cm-2, respectively. Good electrical performances in terms of large memory window and good data retention were observed. Our preparation method is simple, fast and economical.

  12. Hybrid Flexible Resistive Random Access Memory-Gated Transistor for Novel Nonvolatile Data Storage.

    PubMed

    Han, Su-Ting; Zhou, Ye; Chen, Bo; Wang, Chundong; Zhou, Li; Yan, Yan; Zhuang, Jiaqing; Sun, Qijun; Zhang, Hua; Roy, V A L

    2016-01-20

    Here, a single-device demonstration of novel hybrid architecture is reported to achieve programmable transistor nodes which have analogies to flash memory by incorporating a resistive switching random access memory (RRAM) device as a resistive switch gate for field effect transistor (FET) on a flexible substrate. A high performance flexible RRAM with a three-layered structure is fabricated by utilizing solution-processed MoS2 nanosheets sandwiched between poly(methyl methacrylate) polymer layers. Gate coupling with the pentacene-based transistor can be controlled by the RRAM memory state to produce a nonprogrammed state (inactive) and a programmed state (active) with a well-defined memory window. Compared to the reference flash memory device based on the MoS2 floating gate, the hybrid device presents robust access speed and retention ability. Furthermore, the hybrid RRAM-gated FET is used to build an integrated logic circuit and a wide logic window in inverter logic is achieved. The controllable, well-defined memory window, long retention time, and fast access speed of this novel hybrid device may open up new possibilities of realizing fully functional nonvolatile memory for high-performance flexible electronics. PMID:26578160

  13. The Role of Anterior Nuclei of the Thalamus: A Subcortical Gate in Memory Processing: An Intracerebral Recording Study

    PubMed Central

    Štillová, Klára; Jurák, Pavel; Chládek, Jan; Chrastina, Jan; Halámek, Josef; Bočková, Martina; Goldemundová, Sabina; Říha, Ivo; Rektor, Ivan

    2015-01-01

    Objective To study the involvement of the anterior nuclei of the thalamus (ANT) as compared to the involvement of the hippocampus in the processes of encoding and recognition during visual and verbal memory tasks. Methods We studied intracerebral recordings in patients with pharmacoresistent epilepsy who underwent deep brain stimulation (DBS) of the ANT with depth electrodes implanted bilaterally in the ANT and compared the results with epilepsy surgery candidates with depth electrodes implanted bilaterally in the hippocampus. We recorded the event-related potentials (ERPs) elicited by the visual and verbal memory encoding and recognition tasks. Results P300-like potentials were recorded in the hippocampus by visual and verbal memory encoding and recognition tasks and in the ANT by the visual encoding and visual and verbal recognition tasks. No significant ERPs were recorded during the verbal encoding task in the ANT. In the visual and verbal recognition tasks, the P300-like potentials in the ANT preceded the P300-like potentials in the hippocampus. Conclusions The ANT is a structure in the memory pathway that processes memory information before the hippocampus. We suggest that the ANT has a specific role in memory processes, especially memory recognition, and that memory disturbance should be considered in patients with ANT-DBS and in patients with ANT lesions. ANT is well positioned to serve as a subcortical gate for memory processing in cortical structures. PMID:26529407

  14. Working memory gating mechanisms explain developmental change in rule-guided behavior.

    PubMed

    Unger, Kerstin; Ackerman, Laura; Chatham, Christopher H; Amso, Dima; Badre, David

    2016-10-01

    Cognitive control requires choosing contextual information to update into working memory (input gating), maintaining it there (maintenance) stable against distraction, and then choosing which subset of maintained information to use in guiding action (output gating). Recent work has raised the possibility that the development of rule-guided behavior, in the transition from childhood to adolescence, is linked specifically to changes in the gating components of working memory (Amso, Haas, McShane, & Badre, 2014). Given the importance of effective rule-guided behavior for decision making in this developmental transition, we used hierarchical rule tasks to probe the precise developmental dynamics of working memory gating. This mechanistic precision informs ongoing efforts to train cognitive control and working memory operations across typical and atypical development. The results of Experiment 1 verified that the development of rule-guided behavior is uniquely linked to increasing hierarchical complexity but not to increasing maintenance demands across 1st, 2nd, and 3rd order rule tasks. Experiment 2 then investigated whether this developmental trajectory in rule-guided behavior is best explained by change in input gating or output gating. Further, as input versus output gating also tend to correlate with a more proactive versus reactive control strategy in these tasks, we assessed developmental change in the degree to which these two processes were deployed efficiently given the task. Experiment 2 shows that the developmental change observed in Experiment 1 and in Amso et al. (2014) is likely a result of increased efficacy of output gating processes, as well as greater strategic efficiency in that adolescents opt for this costly process less often than children. PMID:27336178

  15. Direct probing of electron and hole trapping into nano-floating-gate in organic field-effect transistor nonvolatile memories

    SciTech Connect

    Cui, Ze-Qun; Wang, Shun; Chen, Jian-Mei; Gao, Xu; Dong, Bin E-mail: chilf@suda.edu.cn Chi, Li-Feng E-mail: chilf@suda.edu.cn Wang, Sui-Dong E-mail: chilf@suda.edu.cn

    2015-03-23

    Electron and hole trapping into the nano-floating-gate of a pentacene-based organic field-effect transistor nonvolatile memory is directly probed by Kelvin probe force microscopy. The probing is straightforward and non-destructive. The measured surface potential change can quantitatively profile the charge trapping, and the surface characterization results are in good accord with the corresponding device behavior. Both electrons and holes can be trapped into the nano-floating-gate, with a preference of electron trapping than hole trapping. The trapped charge quantity has an approximately linear relation with the programming/erasing gate bias, indicating that the charge trapping in the device is a field-controlled process.

  16. Auto- and hetero-associative memory using a 2-D optical logic gate

    NASA Technical Reports Server (NTRS)

    Chao, Tien-Hsin

    1989-01-01

    An optical associative memory system suitable for both auto- and hetero-associative recall is demonstrated. This system utilizes Hamming distance as the similarity measure between a binary input and a memory image with the aid of a two-dimensional optical EXCLUSIVE OR (XOR) gate and a parallel electronics comparator module. Based on the Hamming distance measurement, this optical associative memory performs a nearest neighbor search and the result is displayed in the output plane in real-time. This optical associative memory is fast and noniterative and produces no output spurious states as compared with that of the Hopfield neural network model.

  17. Isolated nanographene crystals for nano-floating gate in charge trapping memory

    PubMed Central

    Yang, Rong; Zhu, Chenxin; Meng, Jianling; Huo, Zongliang; Cheng, Meng; Liu, Donghua; Yang, Wei; Shi, Dongxia; Liu, Ming; Zhang, Guangyu

    2013-01-01

    Graphene exhibits unique electronic properties, and its low dimensionality, structural robustness, and high work-function make it very promising as the charge storage media for memory applications. Along with the development of miniaturized and scaled up devices, nanostructured graphene emerges as an ideal material candidate. Here we proposed a novel non-volatile charge trapping memory utilizing isolate and uniformly distributed nanographene crystals as nano-floating gate with controllable capacity and excellent uniformity. Nanographene charge trapping memory shows large memory window (4.5 V) at low operation voltage (±8 V), good retention (>10 years), chemical and thermal stability (1000°C), as well as tunable memory performance employing with different tunneling layers. The fabrication of such memory structure is compatible with existing semiconductor processing thus has promise on low-cost integrated nanoscale memory applications. PMID:23820388

  18. Radiation-hardened optically reconfigurable gate array exploiting holographic memory characteristics

    NASA Astrophysics Data System (ADS)

    Seto, Daisaku; Watanabe, Minoru

    2015-09-01

    In this paper, we present a proposal for a radiation-hardened optically reconfigurable gate array (ORGA). The ORGA is a type of field programmable gate array (FPGA). The ORGA configuration can be executed by the exploitation of holographic memory characteristics even if 20% of the configuration data are damaged. Moreover, the optoelectronic technology enables the high-speed reconfiguration of the programmable gate array. Such a high-speed reconfiguration can increase the radiation tolerance of its programmable gate array to 9.3 × 104 times higher than that of current FPGAs. Through experimentation, this study clarified the configuration dependability using the impulse-noise emulation and high-speed configuration capabilities of the ORGA with corrupt configuration contexts. Moreover, the radiation tolerance of the programmable gate array was confirmed theoretically through probabilistic calculation.

  19. A buffered nondestructive-readout Josephson memory cell with three gates

    SciTech Connect

    Yuh, P.F. )

    1991-03-01

    This paper describes the design and testing of a nondestructive readout memory cell wit buffer gates to eliminate the half-select problem and to increase the operating margins. A 50{mu}m {times} 52{mu}m cell has been fabricated using a Nb/AlO{sub x}/Nb process with 2.5 {mu}m line width and 3.75 {mu}m junction size. The measured margins for data, read-enable, and sense lines are {plus minus}27%, {plus minus}17%, and {plus minus}48%, respectively. Variations of this buffer-gate memory design are also discussed.

  20. Attention Gating in Short-Term Visual Memory.

    ERIC Educational Resources Information Center

    Reeves, Adam; Sperling, George

    1986-01-01

    An experiment is conducted showing that an attention shift to a stream of numerals presented in rapid serial visual presentation mode produces not a total loss, but a systematic distortion of order. An attention gating model (AGM) is developed from a more general attention model. (Author/LMO)

  1. An attention-gating recurrent working memory architecture for emergent speech representation

    NASA Astrophysics Data System (ADS)

    Elshaw, Mark; Moore, Roger K.; Klein, Michael

    2010-06-01

    This paper describes an attention-gating recurrent self-organising map approach for emergent speech representation. Inspired by evidence from human cognitive processing, the architecture combines two main neural components. The first component, the attention-gating mechanism, uses actor-critic learning to perform selective attention towards speech. Through this selective attention approach, the attention-gating mechanism controls access to working memory processing. The second component, the recurrent self-organising map memory, develops a temporal-distributed representation of speech using phone-like structures. Representing speech in terms of phonetic features in an emergent self-organised fashion, according to research on child cognitive development, recreates the approach found in infants. Using this representational approach, in a fashion similar to infants, should improve the performance of automatic recognition systems through aiding speech segmentation and fast word learning.

  2. A novel symmetrical split-gate structure for 2-bit per cell flash memory

    NASA Astrophysics Data System (ADS)

    Liang, Fang; Weiran, Kong; Jing, Gu; Bo, Zhang; Shichang, Zou

    2014-07-01

    A fully self-aligned symmetrical split-gate cell structure for 2-bit per cell flash memory with a very competitive bit size is presented. One common select gate is located between two floating gates and a pair of source/drain junctions are shared by the 2 bits. The fabrication method utilized here to create a self-aligned structure is to form a spacer against the prior layer without any additional mask. Although the cell consists of three channels in a series, the attributes from conventional split gate flash are still preserved with appropriate bias conditions. Program and erase operation is performed by using a source side injection (SSI) and a poly-to-poly tunneling mechanism respectively.

  3. Graphene-ferroelectric metadevices for nonvolatile memory and reconfigurable logic-gate operations

    NASA Astrophysics Data System (ADS)

    Kim, Woo Young; Kim, Hyeon-Don; Kim, Teun-Teun; Park, Hyun-Sung; Lee, Kanghee; Choi, Hyun Joo; Lee, Seung Hoon; Son, Jaehyeon; Park, Namkyoo; Min, Bumki

    2016-01-01

    Memory metamaterials are artificial media that sustain transformed electromagnetic properties without persistent external stimuli. Previous memory metamaterials were realized with phase-change materials, such as vanadium dioxide or chalcogenide glasses, which exhibit memory behaviour with respect to electrically/optically induced thermal stimuli. However, they require a thermally isolated environment for longer retention or strong optical pump for phase-change. Here we demonstrate electrically programmable nonvolatile memory metadevices realised by the hybridization of graphene, a ferroelectric and meta-atoms/meta-molecules, and extend the concept further to establish reconfigurable logic-gate metadevices. For a memory metadevice having a single electrical input, amplitude, phase and even the polarization multi-states were clearly distinguishable with a retention time of over 10 years at room temperature. Furthermore, logic-gate functionalities were demonstrated with reconfigurable logic-gate metadevices having two electrical inputs, with each connected to separate ferroelectric layers that act as the multi-level controller for the doping level of the sandwiched graphene layer.

  4. Graphene–ferroelectric metadevices for nonvolatile memory and reconfigurable logic-gate operations

    PubMed Central

    Kim, Woo Young; Kim, Hyeon-Don; Kim, Teun-Teun; Park, Hyun-Sung; Lee, Kanghee; Choi, Hyun Joo; Lee, Seung Hoon; Son, Jaehyeon; Park, Namkyoo; Min, Bumki

    2016-01-01

    Memory metamaterials are artificial media that sustain transformed electromagnetic properties without persistent external stimuli. Previous memory metamaterials were realized with phase-change materials, such as vanadium dioxide or chalcogenide glasses, which exhibit memory behaviour with respect to electrically/optically induced thermal stimuli. However, they require a thermally isolated environment for longer retention or strong optical pump for phase-change. Here we demonstrate electrically programmable nonvolatile memory metadevices realised by the hybridization of graphene, a ferroelectric and meta-atoms/meta-molecules, and extend the concept further to establish reconfigurable logic-gate metadevices. For a memory metadevice having a single electrical input, amplitude, phase and even the polarization multi-states were clearly distinguishable with a retention time of over 10 years at room temperature. Furthermore, logic-gate functionalities were demonstrated with reconfigurable logic-gate metadevices having two electrical inputs, with each connected to separate ferroelectric layers that act as the multi-level controller for the doping level of the sandwiched graphene layer. PMID:26813710

  5. The nature of working memory gating in Parkinson's disease: A multi-domain signal detection examination.

    PubMed

    Uitvlugt, Mitchell G; Pleskac, Timothy J; Ravizza, Susan M

    2016-04-01

    Distractions are ubiquitous; our brains are inundated with task-irrelevant information. Thus, to remember successfully, one must actively maintain relevant information and prevent distraction from entering working memory. Researchers suggest the basal ganglia-prefrontal pathways are vital to this process by acting as a working memory gate. Using Parkinson's disease as a model of frontostriatal functioning and with signal detection analyses, the present study aims to better characterize the contribution of frontostriatal pathways of this gating process and to determine how it operates across multiple domains. To achieve this, Parkinson's disease patients and healthy controls completed verbal and spatial working memory tasks consisting of three conditions: low-load without distraction; low-load with distraction; and high-load without distraction. Patients were tested both ON and OFF dopaminergic medication, allowing for assessment of the contribution of dorsal and ventral frontostriatal pathways. The results demonstrate that when medication is withheld, Parkinson's patients have a response bias to answer "NO" across all conditions and domains, supporting our hypothesis that the basal ganglia-prefrontal pathways allow or prevent updates of working memory. Contrastingly, medication status affects d' in the distraction condition but not in the high- or low-load conditions. We attribute this to stimulus valuation processes that were impaired by dopaminergic medication overdosing the ventral pathway. These findings are both consistent with the hypothesis that the working memory gate filters spatial and verbal information before it enters into the working memory system, adding support for the gate being a domain-general mechanism of the central executive. PMID:26518210

  6. High Performance Transparent Transistor Memory Devices Using Nano-Floating Gate of Polymer/ZnO Nanocomposites

    NASA Astrophysics Data System (ADS)

    Shih, Chien-Chung; Lee, Wen-Ya; Chiu, Yu-Cheng; Hsu, Han-Wen; Chang, Hsuan-Chun; Liu, Cheng-Liang; Chen, Wen-Chang

    2016-02-01

    Nano-floating gate memory devices (NFGM) using metal nanoparticles (NPs) covered with an insulating polymer have been considered as a promising electronic device for the next-generation nonvolatile organic memory applications NPs. However, the transparency of the device with metal NPs is restricted to 60~70% due to the light absorption in the visible region caused by the surface plasmon resonance effects of metal NPs. To address this issue, we demonstrate a novel NFGM using the blends of hole-trapping poly (9-(4-vinylphenyl) carbazole) (PVPK) and electron-trapping ZnO NPs as the charge storage element. The memory devices exhibited a remarkably programmable memory window up to 60 V during the program/erase operations, which was attributed to the trapping/detrapping of charge carriers in ZnO NPs/PVPK composite. Furthermore, the devices showed the long-term retention time (>105 s) and WRER test (>200 cycles), indicating excellent electrical reliability and stability. Additionally, the fabricated transistor memory devices exhibited a relatively high transparency of 90% at the wavelength of 500 nm based on the spray-coated PEDOT:PSS as electrode, suggesting high potential for transparent organic electronic memory devices.

  7. High Performance Transparent Transistor Memory Devices Using Nano-Floating Gate of Polymer/ZnO Nanocomposites

    PubMed Central

    Shih, Chien-Chung; Lee, Wen-Ya; Chiu, Yu-Cheng; Hsu, Han-Wen; Chang, Hsuan-Chun; Liu, Cheng-Liang; Chen, Wen-Chang

    2016-01-01

    Nano-floating gate memory devices (NFGM) using metal nanoparticles (NPs) covered with an insulating polymer have been considered as a promising electronic device for the next-generation nonvolatile organic memory applications NPs. However, the transparency of the device with metal NPs is restricted to 60~70% due to the light absorption in the visible region caused by the surface plasmon resonance effects of metal NPs. To address this issue, we demonstrate a novel NFGM using the blends of hole-trapping poly (9-(4-vinylphenyl) carbazole) (PVPK) and electron-trapping ZnO NPs as the charge storage element. The memory devices exhibited a remarkably programmable memory window up to 60 V during the program/erase operations, which was attributed to the trapping/detrapping of charge carriers in ZnO NPs/PVPK composite. Furthermore, the devices showed the long-term retention time (>105 s) and WRER test (>200 cycles), indicating excellent electrical reliability and stability. Additionally, the fabricated transistor memory devices exhibited a relatively high transparency of 90% at the wavelength of 500 nm based on the spray-coated PEDOT:PSS as electrode, suggesting high potential for transparent organic electronic memory devices. PMID:26831222

  8. Organic ferroelectric gate field-effect transistor memory using high-mobility rubrene thin film

    NASA Astrophysics Data System (ADS)

    Kanashima, Takeshi; Katsura, Yuu; Okuyama, Masanori

    2014-01-01

    An organic ferroelectric gate field-effect transistor (FET) memory has been fabricated using an organic semiconductor of rubrene thin film with a high mobility and a gate insulating layer of poly(vinylidene fluoride-tetrafluoroethylene) [P(VDF-TeFE)] thin film. A rubrene thin-film sheet was grown by physical vapor transport (PVT), and placed onto a spin-coated P(VDF-TeFE) thin-film layer, and Au source and drain electrodes were formed on this rubrene thin film. A hysteresis loop of the drain current-gate voltage (ID-VG) characteristic has been clearly observed in the ferroelectric gate FET, and is caused by the ferroelectricity. The maximum drain current is 1.5 × 10-6 A, which is about two orders of magnitude larger than that of the P(VDF-TeFE) gate FET using a pentacene thin film. Moreover, the mobility of this organic ferroelectric gate FET using rubrene thin film is 0.71 cm2 V-1 s-1, which is 35 times larger than that of the FET with pentacene thin film.

  9. Slow oscillations in two pairs of dopaminergic neurons gate long-term memory formation in Drosophila.

    PubMed

    Plaçais, Pierre-Yves; Trannoy, Séverine; Isabel, Guillaume; Aso, Yoshinori; Siwanowicz, Igor; Belliart-Guérin, Ghislain; Vernier, Philippe; Birman, Serge; Tanimoto, Hiromu; Preat, Thomas

    2012-04-01

    A fundamental duty of any efficient memory system is to prevent long-lasting storage of poorly relevant information. However, little is known about dedicated mechanisms that appropriately trigger production of long-term memory (LTM). We examined the role of Drosophila dopaminergic neurons in the control of LTM formation and found that they act as a switch between two exclusive consolidation pathways leading to LTM or anesthesia-resistant memory (ARM). Blockade, after aversive olfactory conditioning, of three pairs of dopaminergic neurons projecting on mushroom bodies, the olfactory memory center, enhanced ARM, whereas their overactivation conversely impaired ARM. Notably, blockade of these neurons during the intertrial intervals of a spaced training precluded LTM formation. Two pairs of these dopaminergic neurons displayed sustained calcium oscillations in naive flies. Oscillations were weakened by ARM-inducing massed training and were enhanced during LTM formation. Our results indicate that oscillations of two pairs of dopaminergic neurons control ARM levels and gate LTM. PMID:22366756

  10. An embedded nonvolatile memory cell with spacer floating gate for power management integrated circuit applications

    NASA Astrophysics Data System (ADS)

    Na, Kee-Yeol; Baek, Ki-Ju; Lee, Gun-Woong; Kim, Yeong-Seuk

    2013-08-01

    This paper describes a simple nonvolatile memory cell with a poly-Si spacer floating gate for power management integrated circuit applications. The proposed memory cell is fabricated using a 0.35 μm double-poly high-voltage CMOS process which includes PIP capacitor, LV (5 V), and HV (20 V) CMOS devices. The floating gates of the proposed cell are buried under a LDD spacer oxide; thus the unit cell can be scaled easily in the channel length direction. In addition, any extra photo masking step is not required for the proposed cell in the applied fabrication process. The proposed cell shows an acceptable threshold voltage window of up to 104 cycles and less than 2% threshold voltage shifts in an 85 °C retention test.

  11. Logic gates and memory cells based on single C60 electromechanical transistors

    NASA Astrophysics Data System (ADS)

    Ami, S.; Joachim, C.

    2001-03-01

    The equivalent electrical circuit of a single C60 electromechanical transistor in a planar lay-out is presented using its experimental STM characteristics. This circuit is used to demonstrate that such a hybrid molecular electronic device can be used as a class A amplifier, a NOT or NOR gate and to implement an SRAM memory point. All the devices are simulated using the SPICE routine to find their optimum load resistance and cantilever grid size. The class A amplifier can operate with a cut-off frequency of a few gigahertz while the logic gate and memory are limited to a few tens of megahertz, but for a very small power design in the picowatt range.

  12. Physical implication of transition voltage in organic nano-floating-gate nonvolatile memories

    NASA Astrophysics Data System (ADS)

    Wang, Shun; Gao, Xu; Zhong, Ya-Nan; Zhang, Zhong-Da; Xu, Jian-Long; Wang, Sui-Dong

    2016-07-01

    High-performance pentacene-based organic field-effect transistor nonvolatile memories, using polystyrene as a tunneling dielectric and Au nanoparticles as a nano-floating-gate, show parallelogram-like transfer characteristics with a featured transition point. The transition voltage at the transition point corresponds to a threshold electric field in the tunneling dielectric, over which stored electrons in the nano-floating-gate will start to leak out. The transition voltage can be modulated depending on the bias configuration and device structure. For p-type active layers, optimized transition voltage should be on the negative side of but close to the reading voltage, which can simultaneously achieve a high ON/OFF ratio and good memory retention.

  13. Gate controllable resistive random access memory devices using reduced graphene oxide

    NASA Astrophysics Data System (ADS)

    Hazra, Preetam; Resmi, A. N.; Jinesh, K. B.

    2016-04-01

    The biggest challenge in the resistive random access memory (ReRAM) technology is that the basic operational parameters, such as the set and reset voltages, the current on-off ratios (hence the power), and their operational speeds, strongly depend on the active and electrode materials and their processing methods. Therefore, for its actual technological implementations, the unification of the operational parameters of the ReRAM devices appears to be a difficult task. In this letter, we show that by fabricating a resistive memory device in a thin film transistor configuration and thus applying an external gate bias, we can control the switching voltage very accurately. Taking partially reduced graphene oxide, the gate controllable switching is demonstrated, and the possible mechanisms are discussed.

  14. Investigation of High-k Dielectrics and Metal Gate Electrodes for Non-volatile Memory Applications

    NASA Astrophysics Data System (ADS)

    Jayanti, Srikant

    Due to the increasing demand of non-volatile flash memories in the portable electronics, the device structures need to be scaled down drastically. However, the scalability of traditional floating gate structures beyond 20 nm NAND flash technology node is uncertain. In this regard, the use of metal gates and high-k dielectrics as the gate and interpoly dielectrics respectively, seem to be promising substitutes in order to continue the flash scaling beyond 20nm. Furthermore, research of novel memory structures to overcome the scaling challenges need to be explored. Through this work, the use of high-k dielectrics as IPDs in a memory structure has been studied. For this purpose, IPD process optimization and barrier engineering were explored to determine and improve the memory performance. Specifically, the concept of high-k / low-k barrier engineering was studied in corroboration with simulations. In addition, a novel memory structure comprising a continuous metal floating gate was investigated in combination with high-k blocking oxides. Integration of thin metal FGs and high-k dielectrics into a dual floating gate memory structure to result in both volatile and non-volatile modes of operation has been demonstrated, for plausible application in future unified memory architectures. The electrical characterization was performed on simple MIS/MIM and memory capacitors, fabricated through CMOS compatible processes. Various analytical characterization techniques were done to gain more insight into the material behavior of the layers in the device structure. In the first part of this study, interfacial engineering was investigated by exploring La2O3 as SiO2 scavenging layer. Through the silicate formation, the consumption of low-k SiO2 was controlled and resulted in a significant improvement in dielectric leakage. The performance improvement was also gauged through memory capacitors. In the second part of the study, a novel memory structure consisting of continuous metal FG

  15. High-Performance Flexible Organic Nano-Floating Gate Memory Devices Functionalized with Cobalt Ferrite Nanoparticles.

    PubMed

    Jung, Ji Hyung; Kim, Sunghwan; Kim, Hyeonjung; Park, Jongnam; Oh, Joon Hak

    2015-10-01

    Nano-floating gate memory (NFGM) devices are transistor-type memory devices that use nanostructured materials as charge trap sites. They have recently attracted a great deal of attention due to their excellent performance, capability for multilevel programming, and suitability as platforms for integrated circuits. Herein, novel NFGM devices have been fabricated using semiconducting cobalt ferrite (CoFe2O4) nanoparticles (NPs) as charge trap sites and pentacene as a p-type semiconductor. Monodisperse CoFe2O4 NPs with different diameters have been synthesized by thermal decomposition and embedded in NFGM devices. The particle size effects on the memory performance have been investigated in terms of energy levels and particle-particle interactions. CoFe2O4 NP-based memory devices exhibit a large memory window (≈73.84 V), a high read current on/off ratio (read I(on)/I(off)) of ≈2.98 × 10(3), and excellent data retention. Fast switching behaviors are observed due to the exceptional charge trapping/release capability of CoFe2O4 NPs surrounded by the oleate layer, which acts as an alternative tunneling dielectric layer and simplifies the device fabrication process. Furthermore, the NFGM devices show excellent thermal stability, and flexible memory devices fabricated on plastic substrates exhibit remarkable mechanical and electrical stability. This study demonstrates a viable means of fabricating highly flexible, high-performance organic memory devices. PMID:26153227

  16. The relation between prospective memory and working memory: Evidence from event-related potential data.

    PubMed

    Wang, Ya; Cao, Xiao-Yan; Cui, Ji-Fang; Shum, David H K; Chan, Raymond C K

    2013-08-01

    Event-related potentials were used in this study to investigate the neural correlates of prospective memory and whether working memory is involved in prospective remembering. Thirty undergraduate or graduate students participated in the study. All participants completed a working memory test, namely, the Chinese Letter-Number Span Test, and were divided into two groups: the longer and shorter working memory span groups. They also undertook a prospective memory task while electrophysiological data were recorded. The results showed that participants in the longer working memory span group had shorter reaction times and smaller amplitudes in prospective positivity than participants in the shorter working memory span group. The results suggested that working memory resources are involved in the intention retrieval process of prospective remembering. PMID:26271181

  17. Wavelet analysis and HHG in nanorings: their applications in logic gates and memory mass devices

    NASA Astrophysics Data System (ADS)

    Cricchio, Dario; Fiordilino, Emilio

    2016-01-01

    We study the application of one nanoring driven by a laser field in different states of polarization in logic circuits. In particular we show that assigning Boolean values to different states of the incident laser field and to the emitted signals, we can create logic gates such as OR, XOR and AND. We also show the possibility of making logic circuits such as half-adder and full-adder using one and two nanorings respectively. Using two nanorings we made the Toffoli gate. Finally we use the final angular momentum acquired by the electron to store information and hence show the possibility of using an array of nanorings as a mass memory device.

  18. Wavelet analysis and HHG in nanorings: their applications in logic gates and memory mass devices.

    PubMed

    Cricchio, Dario; Fiordilino, Emilio

    2016-01-28

    We study the application of one nanoring driven by a laser field in different states of polarization in logic circuits. In particular we show that assigning Boolean values to different states of the incident laser field and to the emitted signals, we can create logic gates such as OR, XOR and AND. We also show the possibility of making logic circuits such as half-adder and full-adder using one and two nanorings respectively. Using two nanorings we made the Toffoli gate. Finally we use the final angular momentum acquired by the electron to store information and hence show the possibility of using an array of nanorings as a mass memory device. PMID:26662194

  19. Spatial Relational Memory Requires Hippocampal Adult Neurogenesis

    PubMed Central

    Koehl, Muriel; Ichas, François; De Giorgi, Francesca; Costet, Pierre; Abrous, Djoher Nora; Piazza, Pier Vincenzo

    2008-01-01

    The dentate gyrus of the hippocampus is one of the few regions of the mammalian brain where new neurons are generated throughout adulthood. This adult neurogenesis has been proposed as a novel mechanism that mediates spatial memory. However, data showing a causal relationship between neurogenesis and spatial memory are controversial. Here, we developed an inducible transgenic strategy allowing specific ablation of adult-born hippocampal neurons. This resulted in an impairment of spatial relational memory, which supports a capacity for flexible, inferential memory expression. In contrast, less complex forms of spatial knowledge were unaltered. These findings demonstrate that adult-born neurons are necessary for complex forms of hippocampus-mediated learning. PMID:18509506

  20. In Situ Tuning of Switching Window in a Gate-Controlled Bilayer Graphene-Electrode Resistive Memory Device.

    PubMed

    Tian, He; Zhao, Haiming; Wang, Xue-Feng; Xie, Qian-Yi; Chen, Hong-Yu; Mohammad, Mohammad Ali; Li, Cheng; Mi, Wen-Tian; Bie, Zhi; Yeh, Chao-Hui; Yang, Yi; Wong, H-S Philip; Chiu, Po-Wen; Ren, Tian-Ling

    2015-12-16

    A resistive random access memory (RRAM) device with a tunable switching window is demonstrated for the first time. The SET voltage can be continuously tuned from 0.27 to 4.5 V by electrical gating from -10 to +35 V. The gate-controlled bilayer graphene-electrode RRAM can function as 1D1R and potentially increase the RRAM density. PMID:26500160

  1. More than Memory Impairment in Voltage-Gated Potassium Channel Complex Encephalopathy

    PubMed Central

    Bettcher, Brianne M.; Gelfand, Jeffrey M.; Irani, Sarosh R.; Neuhaus, John; Forner, Sven; Hess, Christopher P.; Geschwind, Michael D.

    2014-01-01

    Objective Autoimmune encephalopathies (AE) are a heterogeneous group of neurological disorders that affect cognition. Although memory difficulties are commonly endorsed, few reports of AE inclusively assess all cognitive domains in detail. Our aim was to perform an unbiased cognitive evaluation of AE patients with voltage-gated potassium channel complex antibodies (VGKCC-Abs) in order to delineate cognitive strengths and weaknesses. Methods We assessed serial VGKCC-Abs AE subjects (n=12) with a comprehensive evaluation of memory, executive functions, visuospatial skills, and language. Clinical MRI (n=10/12) was evaluated. Five subjects had serial cognitive testing available, permitting descriptive analysis of change. Results Subjects demonstrated mild to moderate impairment in memory (mean Z=−1.9) and executive functions (mean Z=−1.5), with variable impairments in language and sparing of visuospatial skills. MRI findings showed T2 hyperintensities in medial temporal lobe (10/10) and basal ganglia (2/10). Serial cognitive examination revealed heterogeneity in cognitive function; whereas most patients improved in one or more domains, residual impairments were observed in some patients. Conclusions This study augments prior neuropsychological analyses in VGKCC-Ab AE by identifying not only memory and executive function deficits, but also language impairments, with preservation of visuospatial functioning. This study further highlights the importance of domain-specific testing to parse out the complex cognitive phenotypes of VGKCC-Ab AE. PMID:24981998

  2. Quantum memory and phase gate in Optical cavities based on EIT

    NASA Astrophysics Data System (ADS)

    Borges, Halyne; Villas-Bôas, Celso

    In this work we investigate theoretically the implementation of an optical quantum memory in a system composed by a single atom, trapped in a high finesse optical cavity. In order to analyse the feasibility of implementing a quantum memory in the atom-cavity system based on the EIT phenomenon, we investigated in detail which parameter configuration the memory efficiency is optimized considering the two different setups. Our results shows that for a asymmetric one-sided cavity, which is the experimental setup commonly used to observe the EIT effect, the memory efficiency value saturates at about 8 . 5 % . Meanwhile, for an one-sided cavity, we observe for a sufficiently high value of the coupling constant g, the efficiency has its maximum value increased considerably, close to 100 % . However, this experimental setup is not suitable to observe cavity-EIT in the transmission spectrum, being necessary another kind of experiment, such as measurements phase difference field that leaves the cavity induced by the control field. Considering this configuration we also showed the implementation of a quantum phase gate based on the same nonlinear effect, where the pulse probe can experience a phase shift on the order of π, due to the presence or absence of a control pulse. Supported by FAPESP (Proc. 2014/12740-1) and INCT-IQ.

  3. Competition and Cooperation among Relational Memory Representations.

    PubMed

    Schwarb, Hillary; Watson, Patrick D; Campbell, Kelsey; Shander, Christopher L; Monti, Jim M; Cooke, Gillian E; Wang, Jane X; Kramer, Arthur F; Cohen, Neal J

    2015-01-01

    Mnemonic processing engages multiple systems that cooperate and compete to support task performance. Exploring these systems' interaction requires memory tasks that produce rich data with multiple patterns of performance sensitive to different processing sub-components. Here we present a novel context-dependent relational memory paradigm designed to engage multiple learning and memory systems. In this task, participants learned unique face-room associations in two distinct contexts (i.e., different colored buildings). Faces occupied rooms as determined by an implicit gender-by-side rule structure (e.g., male faces on the left and female faces on the right) and all faces were seen in both contexts. In two experiments, we use behavioral and eye-tracking measures to investigate interactions among different memory representations in both younger and older adult populations; furthermore we link these representations to volumetric variations in hippocampus and ventromedial PFC among older adults. Overall, performance was very accurate. Successful face placement into a studied room systematically varied with hippocampal volume. Selecting the studied room in the wrong context was the most typical error. The proportion of these errors to correct responses positively correlated with ventromedial prefrontal volume. This novel task provides a powerful tool for investigating both the unique and interacting contributions of these systems in support of relational memory. PMID:26619203

  4. Competition and Cooperation among Relational Memory Representations

    PubMed Central

    Schwarb, Hillary; Watson, Patrick D.; Campbell, Kelsey; Shander, Christopher L.; Monti, Jim M.; Cooke, Gillian E.; Wang, Jane X.; Kramer, Arthur F.; Cohen, Neal J.

    2015-01-01

    Mnemonic processing engages multiple systems that cooperate and compete to support task performance. Exploring these systems’ interaction requires memory tasks that produce rich data with multiple patterns of performance sensitive to different processing sub-components. Here we present a novel context-dependent relational memory paradigm designed to engage multiple learning and memory systems. In this task, participants learned unique face-room associations in two distinct contexts (i.e., different colored buildings). Faces occupied rooms as determined by an implicit gender-by-side rule structure (e.g., male faces on the left and female faces on the right) and all faces were seen in both contexts. In two experiments, we use behavioral and eye-tracking measures to investigate interactions among different memory representations in both younger and older adult populations; furthermore we link these representations to volumetric variations in hippocampus and ventromedial PFC among older adults. Overall, performance was very accurate. Successful face placement into a studied room systematically varied with hippocampal volume. Selecting the studied room in the wrong context was the most typical error. The proportion of these errors to correct responses positively correlated with ventromedial prefrontal volume. This novel task provides a powerful tool for investigating both the unique and interacting contributions of these systems in support of relational memory. PMID:26619203

  5. Serotonergic Mechanisms in Addiction-Related Memories

    PubMed Central

    Nic Dhonnchadha, Bríd Á; Cunningham, Kathryn A.

    2008-01-01

    Drug-associated memories are a hallmark of addiction and a contributing factor in the continued use and relapse to drugs of abuse. Repeated association of drugs of abuse with conditioned stimuli leads to long-lasting behavioral responses that reflect reward-controlled learning and participate in the establishment of addiction. A greater understanding of the mechanisms underlying the formation and retrieval of drug-associated memories may shed light on potential therapeutic approaches to effectively intervene with drug use-associated memory. There is evidence to support the involvement of serotonin (5-HT) neurotransmission in learning and memory formation through the families of the 5-HT1 receptor (5-HT1R) and 5-HT2R which have also been shown to play a modulatory role in the behavioral effects induced by many psychostimulants. While there is a paucity of studies examining the effects of selective 5-HT1AR ligands, the available dataset suggests that 5-HT1BR agonists may inhibit retrieval of cocaine-associated memories. The 5-HT2AR and 5-HT2CR appear to be integral in the strong conditioned associations made between cocaine and environmental cues with 5-HT2AR antagonists and 5-HT2CR agonists possessing potency in blocking retrieval of cocaine-associated memories following cocaine self-administration procedures. The complex anatomical connectivity between 5-HT neurons and other neuronal phenotypes in limbic-corticostriatal brain structures, the heterogeneity of 5-HT receptors (5-HTXR) and the conflicting results of behavioral experiments which employ non-specific 5-HTXR ligands contribute to the complexity of interpreting the involvement of 5-HT systems in addictive-related memory processes. This review briefly traces the history of 5-HT involvement in retrieval of drug-cue associations and future targets of serotonergic manipulation that may reduce the impact that drug cues have on addictive behavior and relapse. PMID:18639587

  6. Investigation of metal oxide dielectrics for non-volatile floating gate and resistance switching memory applications

    NASA Astrophysics Data System (ADS)

    Chakrabarti, Bhaswar

    Floating gate transistor based flash memories have seen more than a decade of continuous growth as the prominent non-volatile memory technology. However, the recent trends indicate that the scaling of flash memory is expected to saturate in the near future. Several alternative technologies are being considered for the replacement of flash in the near future. The basic motivation for this work is to investigate the material properties of metal oxide based high-k dielectrics for potential applications in floating gate and resistance switching memory applications. This dissertation can be divided into two main sections. In the first section, the tunneling characteristics of the SiO2/HfO 2 stacks were investigated. Previous theoretical studies for thin SiO 2/ thick high-k stacks predict an increase in tunneling current in the high-bias regime (better programming) and a decrease in the low-bias regime (better retention) in comparison to pure SiO2 of same equivalent oxide thickness (EOT). However, our studies indicated that the performance improvement in SiO2/HfO2 stacks with thick HfO2 layer is difficult due to significant amount of charge traps in thick HfO2 layers. Oxygen anneal on the stacks did not improve the programming current and retention. X-ray photoelectron spectroscopy (XPS) studies indicated that this was due to formation of an interfacial oxide layer. The second part of the dissertation deals with the investigation of resistive switching in metal oxides. Although promising, practical applications of resistive random access memories (RRAM) require addressing several issues including high forming voltage, large operating currents and reliability. We first investigated resistive switching in HfTiOx nanolaminate with conventional TiN electrodes. The forming-free switching observed in the structures could be described by the quantum point contact model. The modelling results indicated that the forming-free characteristics can be due to a higher number of

  7. Novel process for widening memory window of sub-200 nm ferroelectric-gate field-effect transistor by ferroelectric coating the gate-stack sidewall

    NASA Astrophysics Data System (ADS)

    Van Hai, Le; Takahashi, Mitsue; Zhang, Wei; Sakai, Shigeki

    2015-01-01

    Ferroelectric-gate field-effect transistors (FeFETs) with metallurgical-gate lengths of 140 nm, 160 nm and 190 nm were successfully fabricated using a novel fabrication process. The gate stacks of the FeFETs were Pt/Sr0.8Ca0.2Bi2Ta2O9(SCBT)/HfO2/Si. Key to the process was covering the as-etched gate-stack sidewalls with SCBT precursor films and annealing altogether. The FeFETs which underwent the novel process showed larger memory windows than those without the process by about 0.5 V at scanned gate-voltages of 1 ± 5 V. Endurances of the FeFETs made by the novel process were measured up to 109 cycles with good separations of the on- and off-states. The endurance pulses were 1 ± 5 V with 2 μs period. Good data-retentions of them were also demonstrated which were measured for at least 6.5 days.

  8. Multi-dot floating-gates for nonvolatile semiconductor memories: Their ion beam synthesis and morphology

    SciTech Connect

    Mueller, T.; Heinig, K.-H.; Moeller, W.; Bonafos, C.; Coffin, H.; Cherkashin, N.; Assayag, G. Ben; Schamm, S.; Zanchi, G.; Claverie, A.; Tence, M.; Colliex, C.

    2004-09-20

    Scalability and performance of current flash memories can be improved substantially by replacing the floating polycrystalline-silicon gate by a layer of Si dots. Here, we present both experimental and theoretical studies on ion beam synthesis of multi-dot layers consisting of Si nanocrystals (NCs) embedded in the gate oxide. Former studies have suffered from the weak Z contrast between Si and SiO{sub 2} in transmission electron microscopy (TEM). This letter maps Si plasmon losses with a scanning TEM equipped with a parallel electron energy loss spectroscopy system. Kinetic Monte Carlo simulations of Si phase separation have been performed and compared with Si plasmon maps. Predicted and measured Si morphologies agree remarkably well, both change with increasing ion fluence from isolated NCs to spinodal pattern. However, the predicted fluences are lower than the experimental ones. We identify as the main reason of this discrepancy the partial oxidation of implanted Si by atmospheric humidity, which penetrates into the as-implanted SiO{sub 2}.

  9. Transparent photostable ZnO nonvolatile memory transistor with ferroelectric polymer and sputter-deposited oxide gate

    SciTech Connect

    Park, C. H.; Im, Seongil; Yun, Jungheum; Lee, Gun Hwan; Lee, Byoung H.; Sung, Myung M.

    2009-11-30

    We report on the fabrication of transparent top-gate ZnO nonvolatile memory thin-film transistors (NVM-TFTs) with 200 nm thick poly(vinylidene fluoride/trifluoroethylene) ferroelectric layer; semitransparent 10 nm thin AgO{sub x} and transparent 130 nm thick indium-zinc oxide (IZO) were deposited on the ferroelectric polymer as gate electrode by rf sputtering. Our semitransparent NVM-TFT with AgO{sub x} gate operates under low voltage write-erase (WR-ER) pulse of {+-}20 V, but shows some degradation in retention property. In contrast, our transparent IZO-gated device displays very good retention properties but requires anomalously higher pulse of {+-}70 V for WR and ER states. Both devices stably operated under visible illuminations.

  10. Memory characteristics of metal-oxide-semiconductor capacitor with high density cobalt nanodots floating gate and HfO2 blocking dielectric

    NASA Astrophysics Data System (ADS)

    Pei, Yanli; Yin, Chengkuan; Kojima, Toshiya; Nishijima, Masahiko; Fukushima, Takafumi; Tanaka, Tetsu; Koyanagi, Mitsumasa

    2009-07-01

    In this letter, cobalt nanodots (Co-NDs) had been formed via a self-assembled nanodot deposition. High resolution transmission electron microscopy and x-ray photoelectron spectroscopy analyses clearly show that the high metallic Co-ND is crystallized with small size of ˜2 nm and high density of (4-5)×1012/cm2. The metal-oxide-semiconductor device with high density Co-NDs floating gate and high-k HfO2 blocking dielectric exhibits a wide range memory window (0-12 V) due to the charge trapping into and distrapping from Co-NDs. After 10 years retention, a large memory window of ˜1.3 V with a low charge loss of ˜47% was extrapolated. The relative longer data retention demonstrates the advantage of Co-NDs for nonvolatile memory application.

  11. Two-terminal floating-gate memory with van der Waals heterostructures for ultrahigh on/off ratio.

    PubMed

    Vu, Quoc An; Shin, Yong Seon; Kim, Young Rae; Nguyen, Van Luan; Kang, Won Tae; Kim, Hyun; Luong, Dinh Hoa; Lee, Il Min; Lee, Kiyoung; Ko, Dong-Su; Heo, Jinseong; Park, Seongjun; Lee, Young Hee; Yu, Woo Jong

    2016-01-01

    Concepts of non-volatile memory to replace conventional flash memory have suffered from low material reliability and high off-state current, and the use of a thick, rigid blocking oxide layer in flash memory further restricts vertical scale-up. Here, we report a two-terminal floating gate memory, tunnelling random access memory fabricated by a monolayer MoS2/h-BN/monolayer graphene vertical stack. Our device uses a two-terminal electrode for current flow in the MoS2 channel and simultaneously for charging and discharging the graphene floating gate through the h-BN tunnelling barrier. By effective charge tunnelling through crystalline h-BN layer and storing charges in graphene layer, our memory device demonstrates an ultimately low off-state current of 10(-14) A, leading to ultrahigh on/off ratio over 10(9), about ∼10(3) times higher than other two-terminal memories. Furthermore, the absence of thick, rigid blocking oxides enables high stretchability (>19%) which is useful for soft electronics. PMID:27586841

  12. FOREWORD: Shape Memory and Related Technologies

    NASA Astrophysics Data System (ADS)

    Liu, Yong

    2005-10-01

    The International Symposium on Shape Memory and Related Technologies (SMART2004) successfully took place in Singapore from November 24 to 26, 2004. SMART2004 aimed to provide a forum for presenting and discussing recent developments in the processing, characterization, application and performance prediction of shape memory materials, particularly shape memory alloys and magnetic shape memory materials. In recent years, we have seen a surge in the research and application of shape memory materials. This is due on the one hand to the successful applications of shape memory alloys (SMAs), particularly NiTi (nitinol), in medical practices and, on the other hand, to the discovery of magnetic shape memory (MSM) materials (or, ferromagnetic shape memory alloys, FSMAs). In recent years, applications of SMAs in various engineering practices have flourished owing to the unique combination of novel properties including high power density related to shape recovery, superelasticity with tunable hysteresis, high damping capacity combined with good fatigue resistance, excellent wear resistance due to unconventional deformation mechanisms (stress-induced phase transformation and martensite reorientation), and excellent biocompatibility and anticorrosion resistance, etc. In~the case of MSMs (or FSMAs), their giant shape change in a relatively low magnetic field has great potential to supplement the traditional actuation mechanisms and to have a great impact on the world of modern technology. Common mechanisms existing in both types of materials, namely thermoelastic phase transformation, martensite domain switching and their controlling factors, are of particular interest to the scientific community. Despite some successful applications, some fundamental issues remain unsatisfactorily understood. This conference hoped to link the fundamental research to engineering practices, and to further identify remaining problems in order to further promote the applications of shape memory

  13. All-solution-processed nonvolatile flexible nano-floating gate memory devices

    NASA Astrophysics Data System (ADS)

    Kim, Chaewon; Song, Ji-Min; Lee, Jang-Sik; Lee, Mi Jung

    2014-01-01

    Organic semiconductors have great potential for future electronic applications owing to their inherent flexibility, low cost, light weight and ability to easily cover large areas. However, all of these advantageous material properties can only be harnessed if simple, cheap and low-temperature fabrication processes, which exclude the need for vacuum deposition and are compatible with flexible plastic substrates, are employed. There are a few solution-based techniques such as spin-coating and inkjet printing that meet the above criteria. In this paper, we describe a novel all-solution-processed nonvolatile memory device fabricated on a flexible plastic substrate. The source, drain and gate electrodes were printed using an inkjet printer with a conducting organic solution, while the semiconducting layer was spin-coated with an n-type polymer. The charge-trapping layer was composed of spin-coated reduced graphene oxide (rGO), which was prepared in the form of a solution using Hummer’s method. The fabricated device was characterized in order to confirm the memory characteristics. Device parameters such as threshold voltage shift, retention/endurance characteristics, mechanical robustness and reliability upon bending were also analyzed.

  14. Dynamic memory of a single voltage-gated potassium ion channel: A stochastic nonequilibrium thermodynamic analysis.

    PubMed

    Banerjee, Kinshuk

    2015-05-14

    In this work, we have studied the stochastic response of a single voltage-gated potassium ion channel to a periodic external voltage that keeps the system out-of-equilibrium. The system exhibits memory, resulting from time-dependent driving, that is reflected in terms of dynamic hysteresis in the current-voltage characteristics. The hysteresis loop area has a maximum at some intermediate voltage frequency and disappears in the limits of low and high frequencies. However, the (average) dissipation at long-time limit increases and finally goes to saturation with rising frequency. This raises the question: how diminishing hysteresis can be associated with growing dissipation? To answer this, we have studied the nonequilibrium thermodynamics of the system and analyzed different thermodynamic functions which also exhibit hysteresis. Interestingly, by applying a temporal symmetry analysis in the high-frequency limit, we have analytically shown that hysteresis in some of the periodic responses of the system does not vanish. On the contrary, the rates of free energy and internal energy change of the system as well as the rate of dissipative work done on the system show growing hysteresis with frequency. Hence, although the current-voltage hysteresis disappears in the high-frequency limit, the memory of the ion channel is manifested through its specific nonequilibrium thermodynamic responses. PMID:25978913

  15. Dynamic memory of a single voltage-gated potassium ion channel: A stochastic nonequilibrium thermodynamic analysis

    SciTech Connect

    Banerjee, Kinshuk

    2015-05-14

    In this work, we have studied the stochastic response of a single voltage-gated potassium ion channel to a periodic external voltage that keeps the system out-of-equilibrium. The system exhibits memory, resulting from time-dependent driving, that is reflected in terms of dynamic hysteresis in the current-voltage characteristics. The hysteresis loop area has a maximum at some intermediate voltage frequency and disappears in the limits of low and high frequencies. However, the (average) dissipation at long-time limit increases and finally goes to saturation with rising frequency. This raises the question: how diminishing hysteresis can be associated with growing dissipation? To answer this, we have studied the nonequilibrium thermodynamics of the system and analyzed different thermodynamic functions which also exhibit hysteresis. Interestingly, by applying a temporal symmetry analysis in the high-frequency limit, we have analytically shown that hysteresis in some of the periodic responses of the system does not vanish. On the contrary, the rates of free energy and internal energy change of the system as well as the rate of dissipative work done on the system show growing hysteresis with frequency. Hence, although the current-voltage hysteresis disappears in the high-frequency limit, the memory of the ion channel is manifested through its specific nonequilibrium thermodynamic responses.

  16. Single-crystal C60 needle/CuPc nanoparticle double floating-gate for low-voltage organic transistors based non-volatile memory devices.

    PubMed

    Chang, Hsuan-Chun; Lu, Chien; Liu, Cheng-Liang; Chen, Wen-Chang

    2015-01-01

    Low-voltage organic field-effect transistor memory devices exhibiting a wide memory window, low power consumption, acceptable retention, endurance properties, and tunable memory performance are fabricated. The performance is achieved by employing single-crystal C60 needles and copper phthalocyanine nanoparticles to produce an ambipolar (hole/electron) trapping effect in a double floating-gate architecture. PMID:25358891

  17. Sensorimotor gating and memory deficits in an APP/PS1 double transgenic mouse model of Alzheimer's disease.

    PubMed

    Wang, Hongxing; He, Jue; Zhang, Ruiguo; Zhu, Shenghua; Wang, Junhui; Kong, Lynda; Tan, Qingrong; Li, Xin-Min

    2012-07-15

    Alzheimer's disease (AD) is a neurodegenerative disorder associated with cognitive deterioration and neuropsychiatric symptoms. Sensorimotor gating deficit has been identified in neuropsychiatric diseases. The aim of the present study was to evaluate the possible sensorimotor gating deficit and its correlation to memory impairment and cerebral β-amyloid (Aβ) plaque deposits in an amyloid precursor protein (APP)/presenilin-1 (PS1) double transgenic mouse model of AD. The sensorimotor gating in 3-, 7- and-22-month-old non-transgenic and transgenic mice was evaluated in a prepulse inhibition (PPI) task. Results revealed that the PPI was lower in the 7- and 22-month-old transgenic mice compared with the age-matched control, while the response to startle pulse-alone in the transgenic and non-transgenic mice was comparable. Congo red staining showed that Aβ neuropathology of transgenic mice aggravated with age, and the 3-month-old transgenic mice started to have minimum brain Aβ plaques, corresponding to the early stage of AD phenotype. Furthermore, memory impairment in the 7-month-old transgenic mice was detected in a water maze test. These results suggest that the sensorimotor gating is impaired with the progressing of AD phenotype, and its deficit may be correlated to cerebral Aβ neuropathology and memory impairment in the APP/PS1 transgenic mouse model of AD. PMID:22595040

  18. Investigation of charge trapping mechanism for nanocrystal-based organic nonvolatile floating gate memory devices by band structure analysis

    NASA Astrophysics Data System (ADS)

    Lee, Dong-Hoon; Lim, Ki-Tae; Park, Eung-Kyu; Shin, Ha-Chul; Kim, Chung Soo; Park, Kee-Chan; Ahn, Joung-Real; Bang, Jin Ho; Kim, Yong-Sang

    2016-05-01

    This paper investigates the charge trapping mechanism and electrical performance of CdSe nanocrystals, such as nanoparticles and nanowires in organic floating gate memory devices. Despite of same chemical component, each nanocrystals show different electrical performances with distinct trapping mechanism. CdSe nanoparticles trap holes in the memory device; on the contrary, nanowires trap electrons. This phenomenon is mainly due to the difference of energy band structures between nanoparticles and nanowires, measured by the ultraviolet photoelectron spectroscopy. Also, we investigated the memory performance with C- V characteristics, charging and discharging phenomena, and retention time. The nanoparticle based hole trapping memory device has large memory window while the nanowire based electron trapping memory shows a narrow memory window. In spite of narrow memory window, the nanowire based memory device shows better retention performance of about 55% of the charge even after 104 sec of charging. The contrasting performance of nanoparticle and nanowire is attributed to the difference in their energy band and the morphology of thin layer in the device. [Figure not available: see fulltext.

  19. Asymmetric dual-gate-structured one-transistor dynamic random access memory cells for retention characteristics improvement

    NASA Astrophysics Data System (ADS)

    Kim, Hyungjin; Lee, Jong-Ho; Park, Byung-Gook

    2016-08-01

    One of the major concerns of one-transistor dynamic random access memory (1T-DRAM) is poor retention time. In this letter, a 1T-DRAM cell with two separated asymmetric gates was fabricated and evaluated to improve sensing margin and retention characteristics. It was observed that significantly enhanced sensing margin and retention time over 1 s were obtained using a negatively biased second gate and trapped electrons in the nitride layer because of increased hole capacity in the floating body. These findings indicate that the proposed device could serve as a promising candidate for overcoming retention issues of 1T-DRAM cells.

  20. Verbal declarative memory impairments in specific language impairment are related to working memory deficits

    PubMed Central

    Lum, Jarrad A.G.; Ullman, Michael T.; Conti-Ramsden, Gina

    2015-01-01

    This study examined verbal declarative memory functioning in SLI and its relationship to working memory. Encoding, recall, and recognition of verbal information was examined in children with SLI who had below average working memory (SLILow WM), children with SLI who had average working memory (SLIAvg. WM) and, a group of non-language impaired children with average working memory (TDAvg. WM). The SLILow WM group was significantly worse than both the SLIAvg. WM and TDAvg. WM groups at encoding verbal information and at retrieving verbal information following a delay. In contrast, the SLIAvg. WM group showed no verbal declarative memory deficits. The study demonstrates that verbal declarative memory deficits in SLI only occur when verbal working memory is impaired. Thus SLI declarative memory is largely intact and deficits are likely to be related to working memory impairments. PMID:25660053

  1. Memory styles and related abilities in presentation of self.

    PubMed

    Sehulster, J R

    1995-01-01

    The notion of a person's memory style (elaborated in Sehulster, 1988) was investigated as it relates to the presentation of self. A memory style is defined as a combination of a subject's (perceived) ability in verbal memory, auto- biographical memory, and prospective memory, as measured by the Memory Scale (Sehulster, 1981b). In addition to filling out the Memory Scale, 325 subjects completed a 72-item questionnaire that tapped descriptions of abilities and experiences. The range of abilities and experiences was drawn loosely from Gardner's (1985) notion of multiple intelligences. Distinct patterns of self-report were observed for different memory styles. For instance, a love of listening to music was associated with the memory style that is high in both verbal and autobiographical memory but low in prospective memory; a love for numbers and mathematics was associated with the memory style that is high in both verbal and prospective memory but low in autobiographical memory. The results suggest broad individual differences in information processing. Gender differences are discussed in relation to memory styles. PMID:7733413

  2. Nonvolatile “AND,” “OR,” and “NOT” Boolean logic gates based on phase-change memory

    SciTech Connect

    Li, Y.; Zhong, Y. P.; Deng, Y. F.; Zhou, Y. X.; Xu, L.; Miao, X. S.

    2013-12-21

    Electronic devices or circuits that can implement both logic and memory functions are regarded as the building blocks for future massive parallel computing beyond von Neumann architecture. Here we proposed phase-change memory (PCM)-based nonvolatile logic gates capable of AND, OR, and NOT Boolean logic operations verified in SPICE simulations and circuit experiments. The logic operations are parallel computing and results can be stored directly in the states of the logic gates, facilitating the combination of computing and memory in the same circuit. These results are encouraging for ultralow-power and high-speed nonvolatile logic circuit design based on novel memory devices.

  3. A nonvolatile memory device made of a ferroelectric polymer gate nanodot and a single-walled carbon nanotube.

    PubMed

    Son, Jong Yeog; Ryu, Sangwoo; Park, Yoon-Cheol; Lim, Yun-Tak; Shin, Yun-Sok; Shin, Young-Han; Jang, Hyun Myung

    2010-12-28

    We demonstrate a field-effect nonvolatile memory device made of a ferroelectric copolymer gate nanodot and a single-walled carbon nanotube (SW-CNT). A position-controlled dip-pen nanolithography was performed to deposit a poly(vinylidene fluoride-ran-trifluoroethylene) (PVDF-TrFE) nanodot onto the SW-CNT channel with both a source and drain for field-effect transistor (FET) function. PVDF-TrFE was chosen as a gate dielectric nanodot in order to efficiently exploit its bipolar chemical nature. A piezoelectric force microscopy study confirmed the canonical ferroelectric responses of the PVDF-TrFE nanodot fabricated at the center of the SW-CNT channel. The two distinct ferroelectric polarization states with the stable current retention and fatigue-resistant characteristics make the present PVDF-TrFE-based FET suitable for nonvolatile memory applications. PMID:21050014

  4. Could Talk Therapy Ease Chemo-Related Memory Issues?

    MedlinePlus

    ... 158606.html Could Talk Therapy Ease Chemo-Related Memory Issues? Researchers suggest their approach could improve survivors' ... developed a cognitive-behavioral therapy (CBT) program called Memory and Attention Adaptation Training to help cancer survivors ...

  5. Control of Turing patterns and their usage as sensors, memory arrays, and logic gates

    NASA Astrophysics Data System (ADS)

    Muzika, František; Schreiber, Igor

    2013-10-01

    We study a model system of three diffusively coupled reaction cells arranged in a linear array that display Turing patterns with special focus on the case of equal coupling strength for all components. As a suitable model reaction we consider a two-variable core model of glycolysis. Using numerical continuation and bifurcation techniques we analyze the dependence of the system's steady states on varying rate coefficient of the recycling step while the coupling coefficients of the inhibitor and activator are fixed and set at the ratios 100:1, 1:1, and 4:5. We show that stable Turing patterns occur at all three ratios but, as expected, spontaneous transition from the spatially uniform steady state to the spatially nonuniform Turing patterns occurs only in the first case. The other two cases possess multiple Turing patterns, which are stabilized by secondary bifurcations and coexist with stable uniform periodic oscillations. For the 1:1 ratio we examine modular spatiotemporal perturbations, which allow for controllable switching between the uniform oscillations and various Turing patterns. Such modular perturbations are then used to construct chemical computing devices utilizing the multiple Turing patterns. By classifying various responses we propose: (a) a single-input resettable sensor capable of reading certain value of concentration, (b) two-input and three-input memory arrays capable of storing logic information, (c) three-input, three-output logic gates performing combinations of logical functions OR, XOR, AND, and NAND.

  6. Relating color working memory and color perception.

    PubMed

    Allred, Sarah R; Flombaum, Jonathan I

    2014-11-01

    Color is the most frequently studied feature in visual working memory (VWM). Oddly, much of this work de-emphasizes perception, instead making simplifying assumptions about the inputs served to memory. We question these assumptions in light of perception research, and we identify important points of contact between perception and working memory in the case of color. Better characterization of its perceptual inputs will be crucial for elucidating the structure and function of VWM. PMID:25038028

  7. The relations among abuse, depression, and adolescents' autobiographical memory.

    PubMed

    Johnson, Rebecca J; Greenhoot, Andrea Follmer; Glisky, Elizabeth; McCloskey, Laura A

    2005-06-01

    This study examined the relations among early and recent experiences with abuse, depression, and adolescents' autobiographical memory in a longitudinal study of family violence. Participants' (N = 134) exposure to violence was documented when they were 6 to 12 years old and again when they were 12 to 18 years old. The second assessment included measures of depression and autobiographical memory for childhood experiences. Memory problems were more consistently related to current circumstances than childhood abuse history. For instance, depressive symptoms were associated with increased rates of "overgeneral" childhood memories. Recent exposure to family violence predicted more overgeneral memories, shorter memories, and lower rates of negative memories. The patterns suggest that adolescents currently stressed by depression or family violence might strategically avoid the details of past experiences to regulate affect. PMID:15901224

  8. Sparse distributed memory and related models

    NASA Technical Reports Server (NTRS)

    Kanerva, Pentti

    1992-01-01

    Described here is sparse distributed memory (SDM) as a neural-net associative memory. It is characterized by two weight matrices and by a large internal dimension - the number of hidden units is much larger than the number of input or output units. The first matrix, A, is fixed and possibly random, and the second matrix, C, is modifiable. The SDM is compared and contrasted to (1) computer memory, (2) correlation-matrix memory, (3) feet-forward artificial neural network, (4) cortex of the cerebellum, (5) Marr and Albus models of the cerebellum, and (6) Albus' cerebellar model arithmetic computer (CMAC). Several variations of the basic SDM design are discussed: the selected-coordinate and hyperplane designs of Jaeckel, the pseudorandom associative neural memory of Hassoun, and SDM with real-valued input variables by Prager and Fallside. SDM research conducted mainly at the Research Institute for Advanced Computer Science (RIACS) in 1986-1991 is highlighted.

  9. Multifunctional organic phototransistor-based nonvolatile memory achieved by UV/ozone treatment of the Ta₂O₅ gate dielectric.

    PubMed

    Liu, Xiaohui; Zhao, Haoyan; Dong, Guifang; Duan, Lian; Li, Dong; Wang, Liduo; Qiu, Yong

    2014-06-11

    An organic phototransistor (OPT) shows nonvolatile memory effect due to its novel optical writing and electrical erasing processes. In this work, we utilize an organic light-emitting diode (OLED) as the light source to investigate OPT-based memory (OPTM) performance. It is found that the OPTM can be used as either flash memory or write-once read-many-times memory by adjusting the properties of the Ta2O5 gate dielectric layer. UV/ozone treatment is applied to effectively change dielectric properties of the Ta2O5 film. The mechanisms for this are examined by X-ray photoelectron spectroscopy and capacitance-voltage measurement. It turns out that the densities of oxygen vacancies and defects in the first 1.8 nm Ta2O5 films near the Ta2O5/semiconductor interface are reduced. Furthermore, for the first time, we use this multifunctional OPTM, which unites the photosensitive and memory properties in one single device, as an optical feedback system to tune the brightness of the OLED. Our study suggests that these OPTMs have potential applications in tuning the brightness uniformity, improving the display quality and prolonging the lifetime of flat panel displays. PMID:24813352

  10. Relations between the functions of autobiographical memory and psychological wellbeing.

    PubMed

    Waters, Theodore E A

    2014-01-01

    Researchers have proposed that autobiographical memory serves three basic functions in everyday life: self-definition, social connection, and directing behaviour (e.g., Bluck, Alea, Habermas, & Rubin, 2005). However, no research has examined relations between the functions of autobiographical memory and healthy functioning (i.e., psychological wellbeing). The present research examined the relations between the self, social, and directive functions of autobiographical memory and three factors of psychological wellbeing in single and recurring autobiographical memories. A total of 103 undergraduate students were recruited and provided ratings of each function for four autobiographical memories (two single, two recurring events). Results found that individuals who use their autobiographical memories to serve self, social, and directive functions reported higher levels of Purpose and Communion and Positive Relationships, and that these relations differ slightly by event type. PMID:23537126

  11. Non-Alzheimer's disease—related memory impairment and dementia

    PubMed Central

    Arlt, Sönke

    2013-01-01

    Although Alzheimer's disease (AD) is a common cause of memory impairment and dementia in the elderly disturbed memory function is a widespread subjective and/or objective symptom in a variety of medical conditions. The early detection and correct distinction of AD from non-AD memory impairment is critically important to detect possibly treatable and reversible underlying causes. In the context of clinical research, it is crucial to correctly distinguish between AD or non-AD memory impairment in order to build homogenous study populations for the assessment of new therapeutic possibilities. The distinction of AD from non-AD memory impairment may be difficult, especially in mildly affected patients, due to an overlap of clinical symptoms and biomarker alterations between AD and certain non-AD conditions. This review aims to describe recent aspects of the differential diagnosis of AD and non-AD related memory impairment and how these may be considered in the presence of memory deficits. PMID:24459413

  12. Attending to items in working memory: evidence that refreshing and memory search are closely related.

    PubMed

    Vergauwe, Evie; Cowan, Nelson

    2015-08-01

    Refreshing refers to the use of attention to reactivate items in working memory (WM). In the present study, we aimed to test the hypothesis that refreshing is closely related to memory search. The assumption is that refreshing and memory search both rely on a basic covert memory process that quickly retrieves the memory items into the focus of attention, thereby reactivating the information (Cowan, 1992; Vergauwe & Cowan, 2014). Consistent with the idea that people use their attention to prevent loss from WM, previous research has shown that increasing the proportion of time during which attention is occupied by concurrent processing, thereby preventing refreshing, results in poorer recall performance in complex span tasks (Barrouillet, Portrat, & Camos, Psychological Review, 118, 175-192, 2011). Here, we tested whether recall performance is differentially affected by prolonged attentional capture caused by memory search. If memory search and refreshing both rely on retrieval from WM, then prolonged attentional capture caused by memory search should not lead to forgetting, because memory items are assumed to be reactivated during memory search, in the same way that they would be if that period of time were used for refreshing. Consistent with this idea, prolonged attentional capture had a disruptive effect when it was caused by the need to retrieve knowledge from long-term memory, but not when it was caused by the need to search through the content of WM. The present results support the idea that refreshing operates through a process of retrieval of information into the focus of attention. PMID:25361821

  13. Attending to items in working memory: Evidence that refreshing and memory search are closely related

    PubMed Central

    Vergauwe, Evie; Cowan, Nelson

    2014-01-01

    Refreshing refers to the use of attention to reactivate items in working memory (WM). The current study aims at testing the hypothesis that refreshing is closely related to memory search. The assumption is that refreshing and memory search both rely on a basic covert memory process that quickly retrieves the memory items into the focus of attention, thereby reactivating the information (Cowan, 1992; Vergauwe & Cowan, 2014). Consistent with the idea that people use their attention to prevent loss from WM, previous research has shown that increasing the proportion of time during which attention is occupied by concurrent processing, thereby preventing refreshing, results in poorer recall performance in complex span tasks (Barrouillet, Portrat, & Camos, 2011). Here, we tested whether recall performance is differentially affected by prolonged attentional capture caused by memory search. If memory search and refreshing both rely on retrieval from WM, then prolonged attentional capture caused by memory search should not lead to forgetting because memory items are assumed to be reactivated during memory search, in the same way as they would if that period of time were to be used for refreshing. Consistent with this idea, prolonged attentional capture had a disruptive effect when it was caused by the need to retrieve knowledge from long-term memory but not when it was caused by the need to search through the content of WM. The current results support the idea that refreshing operates through a process of retrieval of information into the focus of attention. PMID:25361821

  14. Relational Memory during Infancy: Evidence from Eye Tracking

    ERIC Educational Resources Information Center

    Richmond, Jenny; Nelson, Charles A.

    2009-01-01

    Here we report evidence from a new eye-tracking measure of relational memory that suggests that 9-month-old infants can encode memories in terms of the relations among items, a function putatively subserved by the hippocampus. Infants learned about the association between faces that were superimposed on unique scenic backgrounds. During test…

  15. Course of Relational and Non-Relational Recognition Memory across the Adult Lifespan

    ERIC Educational Resources Information Center

    Soei, Eleonore; Daum, Irene

    2008-01-01

    Human recognition memory shows a decline during normal ageing, which is thought to be related to age-associated dysfunctions of mediotemporal lobe structures. Whether the hippocampus is critical for human general relational memory or for spatial relational memory only is still disputed. The human perirhinal cortex is thought to be critically…

  16. Cognitive mechanisms associated with auditory sensory gating.

    PubMed

    Jones, L A; Hills, P J; Dick, K M; Jones, S P; Bright, P

    2016-02-01

    Sensory gating is a neurophysiological measure of inhibition that is characterised by a reduction in the P50 event-related potential to a repeated identical stimulus. The objective of this work was to determine the cognitive mechanisms that relate to the neurological phenomenon of auditory sensory gating. Sixty participants underwent a battery of 10 cognitive tasks, including qualitatively different measures of attentional inhibition, working memory, and fluid intelligence. Participants additionally completed a paired-stimulus paradigm as a measure of auditory sensory gating. A correlational analysis revealed that several tasks correlated significantly with sensory gating. However once fluid intelligence and working memory were accounted for, only a measure of latent inhibition and accuracy scores on the continuous performance task showed significant sensitivity to sensory gating. We conclude that sensory gating reflects the identification of goal-irrelevant information at the encoding (input) stage and the subsequent ability to selectively attend to goal-relevant information based on that previous identification. PMID:26716891

  17. Cognitive mechanisms associated with auditory sensory gating

    PubMed Central

    Jones, L.A.; Hills, P.J.; Dick, K.M.; Jones, S.P.; Bright, P.

    2016-01-01

    Sensory gating is a neurophysiological measure of inhibition that is characterised by a reduction in the P50 event-related potential to a repeated identical stimulus. The objective of this work was to determine the cognitive mechanisms that relate to the neurological phenomenon of auditory sensory gating. Sixty participants underwent a battery of 10 cognitive tasks, including qualitatively different measures of attentional inhibition, working memory, and fluid intelligence. Participants additionally completed a paired-stimulus paradigm as a measure of auditory sensory gating. A correlational analysis revealed that several tasks correlated significantly with sensory gating. However once fluid intelligence and working memory were accounted for, only a measure of latent inhibition and accuracy scores on the continuous performance task showed significant sensitivity to sensory gating. We conclude that sensory gating reflects the identification of goal-irrelevant information at the encoding (input) stage and the subsequent ability to selectively attend to goal-relevant information based on that previous identification. PMID:26716891

  18. Advantages of using relative-phase Toffoli gates with an application to multiple control Toffoli optimization

    NASA Astrophysics Data System (ADS)

    Maslov, Dmitri

    2016-02-01

    Various implementations of the Toffoli gate up to a relative phase have been known for years. The advantage over the regular Toffoli gate is its smaller circuit size. However, its use has been often limited to a demonstration of quantum control in designs such as those where the Toffoli gate is being applied last or otherwise for some specific reasons the relative phase does not matter. It was commonly believed that the relative-phase deviations would prevent the relative-phase Toffoli gates from being very helpful in practical large-scale designs. In this paper, we report three circuit identities that provide the means for replacing certain configurations of the multiple control Toffoli gates with their simpler relative-phase implementations, up to a selectable unitary on certain qubits, and without changing the overall functionality. We illustrate the advantage via applying those identities to the optimization of the known circuits implementing multiple control Toffoli gates, and report the reductions in the controlled-not count, T count, as well as the number of ancillae used. We suggest that a further study of the relative-phase Toffoli implementations and their use may yield other optimizations.

  19. Are memory self-efficacy and memory performance related? A meta-analysis.

    PubMed

    Beaudoin, Marine; Desrichard, Olivier

    2011-03-01

    The association between memory self-efficacy (MSE) and memory performance is highly documented in the literature. However, previous studies have produced inconsistent results, and there is no consensus on the existence of a significant link between these two variables. In order to evaluate whether or not the effect size of the MSE-memory performance relationship in healthy adults is significant and to test several theory-driven moderators, we conducted a meta-analysis of published and unpublished studies. A random-effects model analysis of data from 107 relevant studies (673 effect sizes) indicated a low but significant weighted mean correlation between MSE and memory performance, r = .15, 95% CI [.13, .17]. In addition, the mean effect size was significantly moderated by the way MSE was assessed. Memory performance was more strongly related to concurrent MSE (perceived current ability to perform a given task) than it was to global MSE (perceived usual memory ability in general). Furthermore, we found marginally larger MSE-memory performance correlations when the memory situations used to assess MSE involved familiar stimuli. No effect of the method used to assess global MSE or domain MSE (memory rating vs. performance predictions) was found. The results also show that the resource demands of the memory tasks have a moderator effect, as the MSE-performance correlation is larger with free-recall and cued-recall tasks than it is with recognition tasks. Limitations (generalization issues, moderators not considered) and implications for future research are discussed. PMID:21244133

  20. P50 sensory gating is related to performance on select tasks of cognitive inhibition

    PubMed Central

    Yadon, Carly A.; Bugg, Julie M.; Kisley, Michael A.; Davalos, Deana B.

    2009-01-01

    P50 suppression deficits have been documented in clinical and nonclinical populations, but the behavioral correlates of impaired auditory sensory gating remain poorly understood. In the present study, we examined the relationship between P50 gating and healthy adults’ performance on cognitive inhibition tasks. On the basis of load theory (Lavie, Hirst, de Fockert, & Viding, 2004), we predicted that a high perceptual load, a possible consequence of poor auditory P50 sensory gating, would have differential (i.e., positive vs. negative) effects on performance of cognitive inhibition tasks. A dissociation was observed such that P50 gating was negatively related to interference resolution on a Stroop task and positively related to response inhibition on a go/no-go task. Our findings support the idea that a high perceptual load may be beneficial to Stroop performance because of the reduced processing of distractors but detrimental to performance on the go/no-go task because of interference with stimulus discrimination. PMID:19897797

  1. Ultralow-power non-volatile memory cells based on P(VDF-TrFE) ferroelectric-gate CMOS silicon nanowire channel field-effect transistors.

    PubMed

    Van, Ngoc Huynh; Lee, Jae-Hyun; Whang, Dongmok; Kang, Dae Joon

    2015-07-21

    Nanowire-based ferroelectric-complementary metal-oxide-semiconductor (NW FeCMOS) nonvolatile memory devices were successfully fabricated by utilizing single n- and p-type Si nanowire ferroelectric-gate field effect transistors (NW FeFETs) as individual memory cells. In addition to having the advantages of single channel n- and p-type Si NW FeFET memory, Si NW FeCMOS memory devices exhibit a direct readout voltage and ultralow power consumption. The reading state power consumption of this device is less than 0.1 pW, which is more than 10(5) times lower than the ON-state power consumption of single-channel ferroelectric memory. This result implies that Si NW FeCMOS memory devices are well suited for use in non-volatile memory chips in modern portable electronic devices, especially where low power consumption is critical for energy conservation and long-term use. PMID:26098677

  2. Two-dimensional molybdenum disulphide nanosheet-covered metal nanoparticle array as a floating gate in multi-functional flash memories.

    PubMed

    Han, Su-Ting; Zhou, Ye; Chen, Bo; Zhou, Li; Yan, Yan; Zhang, Hua; Roy, V A L

    2015-11-01

    Semiconducting two-dimensional materials appear to be excellent candidates for non-volatile memory applications. However, the limited controllability of charge trapping behaviors and the lack of multi-bit storage studies in two-dimensional based memory devices require further improvement for realistic applications. Here, we report a flash memory consisting of metal NPs-molybdenum disulphide (MoS2) as a floating gate by introducing a metal nanoparticle (NP) (Ag, Au, Pt) monolayer underneath the MoS2 nanosheets. Controlled charge trapping and long data retention have been achieved in a metal (Ag, Au, Pt) NPs-MoS2 floating gate flash memory. This controlled charge trapping is hypothesized to be attributed to band bending and a built-in electric field ξbi between the interface of the metal NPs and MoS2. The metal NPs-MoS2 floating gate flash memories were further proven to be multi-bit memory storage devices possessing a 3-bit storage capability and a good retention capability up to 10(4) s. We anticipate that these findings would provide scientific insight for the development of novel memory devices utilizing an atomically thin two-dimensional lattice structure. PMID:26445097

  3. Distributed Learning Enhances Relational Memory Consolidation

    ERIC Educational Resources Information Center

    Litman, Leib; Davachi, Lila

    2008-01-01

    It has long been known that distributed learning (DL) provides a mnemonic advantage over massed learning (ML). However, the underlying mechanisms that drive this robust mnemonic effect remain largely unknown. In two experiments, we show that DL across a 24 hr interval does not enhance immediate memory performance but instead slows the rate of…

  4. Performance and retention characteristics of nanocrystalline Si floating gate memory with an Al2O3 tunnel layer fabricated by plasma-enhanced atomic layer deposition

    NASA Astrophysics Data System (ADS)

    Ma, Zhongyuan; Wang, Wen; Yang, Huafeng; Jiang, Xiaofan; Yu, Jie; Qin, Hua; Xu, Ling; Chen, Kunji; Huang, Xinfan; Li, Wei; Xu, Jun; Feng, Duan

    2016-02-01

    The down-scaling of nanocrystal Si (nc-Si) floating gate memory must overcome the challenge of leakage current induced by the conventional ultra-thin tunnel layer. We demonstrate that an improved memory performance based on the Al/SiNx/nc-Si/Al2O3/Si structure can be achieved by adopting the Al2O3 tunnel layer fabricated by plasma-enhanced atomic layer deposition. A larger memory window of 7.9 V and better retention characteristics of 4.7 V after 105 s can be obtained compared with the devices containing a conventional SiO2 tunnel layer of equivalent thickness. The capacitance-voltage characteristic reveals that the Al2O3 tunnel layer has a smaller electron barrier height, which ensures that more electrons are injected into the nc-Si dots through the Al2O3/Si interface. The analysis of the conductance-voltage and high-resolution cross-section transmission microscopy reveals that the smaller nc-Si dots dominate in the charge injection in the nc-Si floating gate MOS device with an Al2O3 tunnel layer. With an increase of the nc-Si size, both nc-Si and the interface contribute to the charge storage capacity and retention. The introduction of the Al2O3 tunnel layer in nc-Si floating gate memory provides a method to achieve an improved performance of nc-Si floating gate memory.

  5. Memory-related brain lateralisation in birds and humans.

    PubMed

    Moorman, Sanne; Nicol, Alister U

    2015-03-01

    Visual imprinting in chicks and song learning in songbirds are prominent model systems for the study of the neural mechanisms of memory. In both systems, neural lateralisation has been found to be involved in memory formation. Although many processes in the human brain are lateralised--spatial memory and musical processing involves mostly right hemisphere dominance, whilst language is mostly left hemisphere dominant--it is unclear what the function of lateralisation is. It might enhance brain capacity, make processing more efficient, or prevent occurrence of conflicting signals. In both avian paradigms we find memory-related lateralisation. We will discuss avian lateralisation findings and propose that birds provide a strong model for studying neural mechanisms of memory-related lateralisation. PMID:25036892

  6. Emotional learning selectively and retroactively strengthens memories for related events.

    PubMed

    Dunsmoor, Joseph E; Murty, Vishnu P; Davachi, Lila; Phelps, Elizabeth A

    2015-04-16

    Neurobiological models of long-term memory propose a mechanism by which initially weak memories are strengthened through subsequent activation that engages common neural pathways minutes to hours later. This synaptic tag-and-capture model has been hypothesized to explain how inconsequential information is selectively consolidated following salient experiences. Behavioural evidence for tag-and-capture is provided by rodent studies in which weak early memories are strengthened by future behavioural training. Whether a process of behavioural tagging occurs in humans to transform weak episodic memories into stable long-term memories is unknown. Here we show, in humans, that information is selectively consolidated if conceptually related information, putatively represented in a common neural substrate, is made salient through an emotional learning experience. Memory for neutral objects was selectively enhanced if other objects from the same category were paired with shock. Retroactive enhancements as a result of emotional learning were observed following a period of consolidation, but were not observed in an immediate memory test or for items strongly encoded before fear conditioning. These findings provide new evidence for a generalized retroactive memory enhancement, whereby inconsequential information can be retroactively credited as relevant, and therefore selectively remembered, if conceptually related information acquires salience in the future. PMID:25607357

  7. Two-dimensional molybdenum disulphide nanosheet-covered metal nanoparticle array as a floating gate in multi-functional flash memories

    NASA Astrophysics Data System (ADS)

    Han, Su-Ting; Zhou, Ye; Chen, Bo; Zhou, Li; Yan, Yan; Zhang, Hua; Roy, V. A. L.

    2015-10-01

    Semiconducting two-dimensional materials appear to be excellent candidates for non-volatile memory applications. However, the limited controllability of charge trapping behaviors and the lack of multi-bit storage studies in two-dimensional based memory devices require further improvement for realistic applications. Here, we report a flash memory consisting of metal NPs-molybdenum disulphide (MoS2) as a floating gate by introducing a metal nanoparticle (NP) (Ag, Au, Pt) monolayer underneath the MoS2 nanosheets. Controlled charge trapping and long data retention have been achieved in a metal (Ag, Au, Pt) NPs-MoS2 floating gate flash memory. This controlled charge trapping is hypothesized to be attributed to band bending and a built-in electric field ξbi between the interface of the metal NPs and MoS2. The metal NPs-MoS2 floating gate flash memories were further proven to be multi-bit memory storage devices possessing a 3-bit storage capability and a good retention capability up to 104 s. We anticipate that these findings would provide scientific insight for the development of novel memory devices utilizing an atomically thin two-dimensional lattice structure.Semiconducting two-dimensional materials appear to be excellent candidates for non-volatile memory applications. However, the limited controllability of charge trapping behaviors and the lack of multi-bit storage studies in two-dimensional based memory devices require further improvement for realistic applications. Here, we report a flash memory consisting of metal NPs-molybdenum disulphide (MoS2) as a floating gate by introducing a metal nanoparticle (NP) (Ag, Au, Pt) monolayer underneath the MoS2 nanosheets. Controlled charge trapping and long data retention have been achieved in a metal (Ag, Au, Pt) NPs-MoS2 floating gate flash memory. This controlled charge trapping is hypothesized to be attributed to band bending and a built-in electric field ξbi between the interface of the metal NPs and MoS2. The metal

  8. Could Talk Therapy Ease Chemo-Related Memory Issues?

    MedlinePlus

    ... of Health, the U.S. Department of Health and Human Services, or federal policy. More Health News on: Cancer Chemotherapy Cancer--Living with Cancer Memory Recent Health News Related MedlinePlus Health Topics Cancer ...

  9. Sensory gating, inhibition control and child intelligence: an event-related potentials study.

    PubMed

    Liu, T; Xiao, T; Shi, J; Zhao, L

    2011-08-25

    The current study explored the relationship among sensory gating, inhibition control and human intelligence in two groups of children with different intellectual levels. A Go-Nogo task was adopted to investigate children's behavioral performances in inhibition control processing, and a paired-click paradigm with event-related potentials (ERP) recording was used to explore children's neural activation during sensory gating processing. The behavioral results showed that the intellectually gifted children committed significantly less commission error rate, which indicated that gifted children had better inhibition control than their average peers. The electrophysiological results showed that the gifted group had lower S2P50/S1P50 amplitude ratio than the average group and illustrated that gifted children had stronger sensory gating. The results of correlation analysis between inhibition control performances and sensory gating showed that children with stronger P50 suppression (lower S2/S1 latency ratio) in the fronto-central area and stronger N100 suppression (lower S2/S1 amplitude ratio) in the frontal and fronto-central areas had shorter reaction time in the Go-Nogo task. Moreover, the correlation patterns between sensory gating and inhibition control were different between two groups of children. The present findings further demonstrated the close relationship among sensory gating, inhibition control and human intelligence in children. PMID:21640164

  10. Self-images and related autobiographical memories in schizophrenia.

    PubMed

    Bennouna-Greene, Mehdi; Berna, Fabrice; Conway, Martin A; Rathbone, Clare J; Vidailhet, Pierre; Danion, Jean-Marie

    2012-03-01

    Schizophrenia is a severe mental illness, which affects sense of identity. While the ability to have a coherent vision of the self (i.e., self-images) relies partly on its reciprocal relationships with autobiographical memories, little is known about how memories ground "self-images" in schizophrenia. Twenty-five patients with schizophrenia and 25 controls were asked to give six autobiographical memories related to four self-statements they considered essential for defining their identity. Results showed that patients' self-images were more passive than those of controls. Autobiographical memories underlying self-images were less thematically linked to these self-images in patients. We also found evidence of a weakened sense of self and a deficient organization of autobiographical memories grounding the self in schizophrenia. These abnormalities may account for the poor cohesiveness of the self in schizophrenia. PMID:22040535

  11. Voltage-Gated Sodium Channels: Biophysics, Pharmacology, and Related Channelopathies

    PubMed Central

    Savio-Galimberti, Eleonora; Gollob, Michael H.; Darbar, Dawood

    2012-01-01

    Voltage-gated sodium channels (VGSC) are multi-molecular protein complexes expressed in both excitable and non-excitable cells. They are primarily formed by a pore-forming multi-spanning integral membrane glycoprotein (α-subunit) that can be associated with one or more regulatory β-subunits. The latter are single-span integral membrane proteins that modulate the sodium current (INa) and can also function as cell adhesion molecules. In vitro some of the cell-adhesive functions of the β-subunits may play important physiological roles independently of the α-subunits. Other endogenous regulatory proteins named “channel partners” or “channel interacting proteins” (ChiPs) like caveolin-3 and calmodulin/calmodulin kinase II (CaMKII) can also interact and modulate the expression and/or function of VGSC. In addition to their physiological roles in cell excitability and cell adhesion, VGSC are the site of action of toxins (like tetrodotoxin and saxitoxin), and pharmacologic agents (like antiarrhythmic drugs, local anesthetics, antiepileptic drugs, and newly developed analgesics). Mutations in genes that encode α- and/or β-subunits as well as the ChiPs can affect the structure and biophysical properties of VGSC, leading to the development of diseases termed sodium “channelopathies”.  This review will outline the structure, function, and biophysical properties of VGSC as well as their pharmacology and associated channelopathies and highlight some of the recent advances in this field. PMID:22798951

  12. Aging-related episodic memory decline: are emotions the key?

    PubMed Central

    Kinugawa, Kiyoka; Schumm, Sophie; Pollina, Monica; Depre, Marion; Jungbluth, Carolin; Doulazmi, Mohamed; Sebban, Claude; Zlomuzica, Armin; Pietrowsky, Reinhard; Pause, Bettina; Mariani, Jean; Dere, Ekrem

    2013-01-01

    Episodic memory refers to the recollection of personal experiences that contain information on what has happened and also where and when these events took place. Episodic memory function is extremely sensitive to cerebral aging and neurodegerative diseases. We examined episodic memory performance with a novel test in young (N = 17, age: 21–45), middle-aged (N = 16, age: 48–62) and aged but otherwise healthy participants (N = 8, age: 71–83) along with measurements of trait and state anxiety. As expected we found significantly impaired episodic memory performance in the aged group as compared to the young group. The aged group also showed impaired working memory performance as well as significantly decreased levels of trait anxiety. No significant correlation between the total episodic memory and trait or state anxiety scores was found. The present results show an age-dependent episodic memory decline along with lower trait anxiety in the aged group. Yet, it still remains to be determined whether this difference in anxiety is related to the impaired episodic memory performance in the aged group. PMID:23378831

  13. Floating-gated memory based on carbon nanotube field-effect transistors with Si floating dots

    NASA Astrophysics Data System (ADS)

    Seike, Kohei; Fujii, Yusuke; Ohno, Yasuhide; Maehashi, Kenzo; Inoue, Koichi; Matsumoto, Kazuhiko

    2014-01-01

    We have fabricated a carbon nanotube field-effect transistor (CNTFET)-based nonvolatile memory device with Si floating dots. The electrical characteristics of this memory device were compared with those of devices with a HfO2 charge storage layer or Au floating dots. For a sweep width of 6 V, the memory window of the devices with the Si floating dots increased twofold as compared with that of the devices with the HfO2 layer. Moreover, the retention characteristics revealed that, for the device with the Au floating dots, the off-state had almost the same current as the on-state at the 400th s. However, the devices with the Si floating dots had longer-retention characteristics. The results indicate that CNTFET-based devices with Si floating dots are promising candidates for low-power consumption nonvolatile memory devices.

  14. Aerobic fitness predicts relational memory but not item memory performance in healthy young adults.

    PubMed

    Baym, Carol L; Khan, Naiman A; Pence, Ari; Raine, Lauren B; Hillman, Charles H; Cohen, Neal J

    2014-11-01

    Health factors such as an active lifestyle and aerobic fitness have long been linked to decreased risk of cardiovascular disease, stroke, and other adverse health outcomes. Only more recently have researchers begun to investigate the relationship between aerobic fitness and memory function. Based on recent findings in behavioral and cognitive neuroscience showing that the hippocampus might be especially sensitive to the effects of exercise and fitness, the current study assessed hippocampal-dependent relational memory and non-hippocampal-dependent item memory in young adults across a range of aerobic fitness levels. Aerobic fitness was assessed using a graded exercise test to measure oxygen consumption during maximal exercise (VO2max), and relational and item memory were assessed using behavioral and eye movement measures. Behavioral results indicated that aerobic fitness was positively correlated with relational memory performance but not item memory performance, suggesting that the beneficial effects of aerobic fitness selectively affect hippocampal function and not that of the surrounding medial temporal lobe cortex. Eye movement results further supported the specificity of this fitness effect to hippocampal function, in that aerobic fitness predicted disproportionate preferential viewing of previously studied relational associations but not of previously viewed items. Potential mechanisms underlying this pattern of results, including neurogenesis, are discussed. PMID:24893739

  15. Memory deficit in patients with schizophrenia and posttraumatic stress disorder: relational vs item-specific memory

    PubMed Central

    Jung, Wookyoung; Lee, Seung-Hwan

    2016-01-01

    It has been well established that patients with schizophrenia have impairments in cognitive functioning and also that patients who experienced traumatic events suffer from cognitive deficits. Of the cognitive deficits revealed in schizophrenia or posttraumatic stress disorder (PTSD) patients, the current article provides a brief review of deficit in episodic memory, which is highly predictive of patients’ quality of life and global functioning. In particular, we have focused on studies that compared relational and item-specific memory performance in schizophrenia and PTSD, because measures of relational and item-specific memory are considered the most promising constructs for immediate tangible development of clinical trial paradigm. The behavioral findings of schizophrenia are based on the tasks developed by the Cognitive Neuroscience Treatment Research to Improve Cognition in Schizophrenia (CNTRICS) initiative and the Cognitive Neuroscience Test Reliability and Clinical Applications for Schizophrenia (CNTRACS) Consortium. The findings we reviewed consistently showed that schizophrenia and PTSD are closely associated with more severe impairments in relational memory compared to item-specific memory. Candidate brain regions involved in relational memory impairment in schizophrenia and PTSD are also discussed. PMID:27274250

  16. Effects of thickness and geometric variations in the oxide gate stack on the nonvolatile memory behaviors of charge-trap memory thin-film transistors

    NASA Astrophysics Data System (ADS)

    Bak, Jun Yong; Kim, So-Jung; Byun, Chun-Won; Pi, Jae-Eun; Ryu, Min-Ki; Hwang, Chi Sun; Yoon, Sung-Min

    2015-09-01

    Device designs of charge-trap oxide memory thin-film transistors (CTM-TFTs) were investigated to enhance their nonvolatile memory performances. The first strategy was to optimize the film thicknesses of the tunneling and charge-trap (CT) layers in order to meet requirements of both higher operation speed and longer retention time. While the program speed and memory window were improved for the device with a thinner tunneling layer, a long retention time was obtained only for the device with a tunneling layer thicker than 5 nm. The carrier concentration and charge-trap densities were optimized in the 30-nm-thick CT layer. It was observed that 10-nm-thick tunneling, 30-nm-thick CT, and 50-nm-thick blocking layers were the best configuration for our proposed CTM-TFTs, where a memory on/off margin higher than 107 was obtained, and a memory margin of 6.6 × 103 was retained even after the lapse of 105 s. The second strategy was to examine the effects of the geometrical relations between the CT and active layers for the applications of memory elements embedded in circuitries. The CTM-TFTs fabricated without an overlap between the CT layer and the drain electrode showed an enhanced program speed by the reduced parasitic capacitance. The drain-bias disturbance for the memory off-state was effectively suppressed even when a higher read-out drain voltage was applied. Appropriate device design parameters, such as the film thicknesses of each component layer and the geometrical relations between them, can improve the memory performances and expand the application fields of the proposed CTM-TFTs.

  17. Novel gate-all-around polycrystalline silicon nanowire memory device with HfAlO charge-trapping layer

    NASA Astrophysics Data System (ADS)

    Lee, Ko-Hui; Lin, Horng-Chih; Huang, Tiao-Yuan

    2014-01-01

    Gate-all-around (GAA) nanowire (NW) memory devices with a SiN- or Hf-based charge-trapping (CT) layer of the same thickness were studied in this work. The GAA NW devices were fabricated with planar thin-film transistors (TFTs) on the same substrate using a novel scheme without resorting to the use of advanced lithographic tools. Owing to their higher dielectric constant, the GAA NW devices with a HfO2 or HfAlO CT layer show greatly enhanced programming/erasing (P/E) efficiency as compared with those with a SiN CT layer. Furthermore, the incorporation of Al into the Hf-based dielectric increases the thermal stability of the CT layer, improving retention and endurance characteristics.

  18. Formation of holographic memory for optically reconfigurable gate array by angle-multiplexing recording of multi-circuit information in liquid crystal composites

    NASA Astrophysics Data System (ADS)

    Ogiwara, Akifumi; Maekawa, Hikaru; Watanabe, Minoru; Moriwaki, Retsu

    2014-02-01

    A holographic polymer-dispersed liquid crystal (HPDLC) memory to record multi-context information for an optically reconfigurable gate array is formed by the angle-multiplexing recording using a successive laser exposure in liquid crystal (LC) composites. The laser illumination system is constructed using the half mirror and photomask written by the different configuration contexts placed on the motorized stages under the control of a personal computer. The fabricated holographic memory implements a precise reconstruction of configuration contexts corresponding to the various logical circuits such as OR circuit and NOR circuit by the laser illumination at different incident angle in the HPDLC memory.

  19. Azobenzene-functionalized gold nanoparticles as hybrid double-floating-gate in pentacene thin-film transistors/memories with enhanced response, retention, and memory windows.

    PubMed

    Tseng, Chiao-Wei; Huang, Ding-Chi; Tao, Yu-Tai

    2013-10-01

    Gold nanoparticles (Au-NPs) with surfaces covered with a self-assembled monolayer of azobenzene derivatives were prepared at the interface of dielectric insulator SiO2 and pentacene thin film. Transistors constructed with these composite channel materials exhibited electric bistability upon different gate biases, with the monolayer serving as a barrier layer, a work function modulator, as well as additional charge trapping sites at the Au-NPs/semiconductor interface at the same time. In comparison with simple alkanethiol monolayer-covered Au-NPs, the CH3-substituted azobenzene-functionalized Au-NPs result in a transistor memory device with about 70% more charges trapped, much faster response time as well as higher retention time. Besides, depending on the substituent on the azobenzene moieties (CH3, H, or CF3) and the tethering alkyl chain length, the speed at which the carriers are trapped (affecting switching response) and the stability of the carriers that are trapped (affecting memory retention) can be modulated to improve the device performance. The structural characterization and electronic characteristics of these devices will be detailed. PMID:24025199

  20. The role of nicotine on respiratory sensory gating measured by respiratory-related evoked potentials.

    PubMed

    Chan, Pei-Ying Sarah; Davenport, P W

    2010-03-01

    Respiratory perception can be altered by changes in emotional or psychological states. This may be due to affective (i.e., anxiety) modulation of respiratory sensory gating. Nicotine withdrawal induces elevated anxiety and decreased somatosensory gating. Respiratory sensory gating is evidenced by decreased amplitude of the respiratory-related evoked potentials (RREP) N(1) peak for the second occlusion (S2) when two 150-ms occlusions are presented with a 500-ms interval during an inspiration. The N(1) peak amplitude ratio of the S2 and first occlusion (S1) (S2/S1) is <0.5 and due to central neural sensory gating. We hypothesized that withdrawal from nicotine is anxiogenic and reduces respiratory gating in smokers. The RREP was recorded in smokers with 12-h withdrawal from nicotine and nonsmokers using a paired occlusion protocol. In smokers, the RREP was measured after nicotine withdrawal, then with either nicotine or placebo gum, followed by the second RREP trial. Nonsmokers received only placebo gum. After nicotine withdrawal, the smokers had a higher state anxiety compared with nonsmokers. There was a significant interaction between groups (nonsmokers vs. smokers with nicotine vs. smokers with placebo) and test (pre- vs. posttreatment) in RREP N(1) peak amplitude S2/S1. The S2/S1 in the smokers were larger than in nonsmokers before treatment. After gum treatment, the smoker-with-placebo group had a significantly larger S2/S1 than the other two groups. The S2/S1 was significantly decreased after the administration of nicotine gum in smokers due to significantly decreased S2 amplitudes. The RREP N(f) and P(1) peaks were unaffected. These results demonstrated that respiratory sensory gating was decreased in smokers after nicotine withdrawal. Nicotine increased respiratory sensory gating in smokers with a S2/S1 similar to that of the nonsmokers. Nicotine did not change respiratory sensory information arrival, but secondary information processing in respiratory

  1. Graphene quantum dots as a highly efficient solution-processed charge trapping medium for organic nano-floating gate memory.

    PubMed

    Ji, Yongsung; Kim, Juhan; Cha, An-Na; Lee, Sang-A; Lee, Myung Woo; Suh, Jung Sang; Bae, Sukang; Moon, Byung Joon; Lee, Sang Hyun; Lee, Dong Su; Wang, Gunuk; Kim, Tae-Wook

    2016-04-01

    A highly efficient solution-processible charge trapping medium is a prerequisite to developing high-performance organic nano-floating gate memory (NFGM) devices. Although several candidates for the charge trapping layer have been proposed for organic memory, a method for significantly increasing the density of stored charges in nanoscale layers remains a considerable challenge. Here, solution-processible graphene quantum dots (GQDs) were prepared by a modified thermal plasma jet method; the GQDs were mostly composed of carbon without any serious oxidation, which was confirmed by x-ray photoelectron spectroscopy. These GQDs have multiple energy levels because of their size distribution, and they can be effectively utilized as charge trapping media for organic NFGM applications. The NFGM device exhibited excellent reversible switching characteristics, with an on/off current ratio greater than 10(6), a stable retention time of 10(4) s and reliable cycling endurance over 100 cycles. In particular, we estimated that the GQDs layer trapped ∼7.2 × 10(12) cm(-2) charges per unit area, which is a much higher density than those of other solution-processible nanomaterials, suggesting that the GQDs layer holds promise as a highly efficient nanoscale charge trapping material. PMID:26905768

  2. Floating gate memory with charge storage dots array formed by Dps protein modified with site-specific binding peptides

    NASA Astrophysics Data System (ADS)

    Kamitake, Hiroki; Uenuma, Mutsunori; Okamoto, Naofumi; Horita, Masahiro; Ishikawa, Yasuaki; Yamashita, Ichro; Uraoka, Yukiharu

    2015-05-01

    We report a nanodot (ND) floating gate memory (NFGM) with a high-density ND array formed by a biological nano process. We utilized two kinds of cage-shaped proteins displaying SiO2 binding peptide (minTBP-1) on their outer surfaces: ferritin and Dps, which accommodate cobalt oxide NDs in their cavities. The diameters of the cobalt NDs were regulated by the cavity sizes of the proteins. Because minTBP-1 is strongly adsorbed on the SiO2 surface, high-density cobalt oxide ND arrays were obtained by a simple spin coating process. The densities of cobalt oxide ND arrays based on ferritin and Dps were 6.8 × 1011 dots cm-2 and 1.2 × 1012 dots cm-2, respectively. After selective protein elimination and embedding in a metal-oxide-semiconductor (MOS) capacitor, the charge capacities of both ND arrays were evaluated by measuring their C-V characteristics. The MOS capacitor embedded with the Dps ND array showed a wider memory window than the device embedded with the ferritin ND array. Finally, we fabricated an NFGM with a high-density ND array based on Dps, and confirmed its competent writing/erasing characteristics and long retention time.

  3. Revised associative inference paradigm confirms relational memory impairment in schizophrenia

    PubMed Central

    Armstrong, Kristan; Williams, Lisa E.; Heckers, Stephan

    2013-01-01

    Objective Patients with schizophrenia have widespread cognitive impairments, with selective deficits in relational memory. We previously reported a differential relational memory deficit in schizophrenia using the Associative Inference Paradigm (AIP), a task suggested by the Cognitive Neuroscience Treatment Research to Improve Cognition in Schizophrenia (CNTRICS) initiative to examine relational memory. However, the AIP had limited feasibility for testing in schizophrenia due to high attrition of schizophrenia patients during training. Here we developed and tested a revised version of the AIP to improve feasibility. Method 30 healthy control and 37 schizophrenia subjects received 3 study-test sessions on 3 sets of paired associates: H-F1 (house paired with face), H-F2 (same house paired with new face), and F3-F4 (two novel faces). After training, subjects were tested on the trained, non-inferential Face-Face pairs (F3-F4) and novel, inferential Face-Face pairs (F1-F2), constructed from the faces of the trained House-Face pairs. Results Schizophrenia patients were significantly more impaired on the inferential F1-F2 pairs than the non-inferential F3-F4 pairs, providing evidence for a differential relational memory deficit. Only 8 percent of schizophrenia patients were excluded from testing due to poor training performance. Conclusions The revised AIP confirmed the previous finding of a relational memory deficit in a larger and more representative sample of schizophrenia patients. PMID:22612578

  4. The hippocampus and memory for orderly stimulus relations.

    PubMed

    Dusek, J A; Eichenbaum, H

    1997-06-24

    Human declarative memory involves a systematic organization of information that supports generalizations and inferences from acquired knowledge. This kind of memory depends on the hippocampal region in humans, but the extent to which animals also have declarative memory, and whether inferential expression of memory depends on the hippocampus in animals, remains a major challenge in cognitive neuroscience. To examine these issues, we used a test of transitive inference pioneered by Piaget to assess capacities for systematic organization of knowledge and logical inference in children. In our adaptation of the test, rats were trained on a set of four overlapping odor discrimination problems that could be encoded either separately or as a single representation of orderly relations among the odor stimuli. Normal rats learned the problems and demonstrated the relational memory organization through appropriate transitive inferences about items not presented together during training. By contrast, after disconnection of the hippocampus from either its cortical or subcortical pathway, rats succeeded in acquiring the separate discrimination problems but did not demonstrate transitive inference, indicating that they had failed to develop or could not inferentially express the orderly organization of the stimulus elements. These findings strongly support the view that the hippocampus mediates a general declarative memory capacity in animals, as it does in humans. PMID:9192700

  5. Positive and Negative Symptoms in Schizophrenia Relate to Distinct Oscillatory Signatures of Sensory Gating

    PubMed Central

    Keil, Julian; Roa Romero, Yadira; Balz, Johanna; Henjes, Melissa; Senkowski, Daniel

    2016-01-01

    Oscillatory activity in neural populations and temporal synchronization within these populations are important mechanisms contributing to perception and cognition. In schizophrenia, perception and cognition are impaired. Aberrant gating of irrelevant sensory information, which has been related to altered oscillatory neural activity, presumably contributes to these impairments. However, the link between schizophrenia symptoms and sensory gating deficits, as reflected in oscillatory activity, is not clear. In this electroencephalography study, we used a paired-stimulus paradigm to investigate frequency-resolved oscillatory activity in 22 schizophrenia patients and 22 healthy controls. We found sensory gating deficits in patients compared to controls, as reflected in reduced gamma-band power and alpha-band phase synchrony difference between the first and the second auditory stimulus. We correlated these markers of neural activity with a five-factor model of the Positive and Negative Syndrome Scale. Gamma-band power sensory gating was positively correlated with positive symptoms. Moreover, alpha-band phase synchrony sensory gating was negatively correlated with negative symptoms. A cluster analysis revealed three schizophrenia phenotypes, characterized by (i) aberrant gamma-band power and high positive symptoms, (ii) aberrant alpha-band phase synchrony, low positive, and low negative symptom scores or (iii) by intact sensory gating and high negative symptoms. Our study demonstrates that aberrant neural synchronization, as reflected in gamma-band power and alpha-band phase synchrony, relates to the schizophrenia psychopathology. Different schizophrenia phenotypes express distinct levels of positive and negative symptoms as well as varying degrees of aberrant oscillatory neural activity. Identifying the individual phenotype might improve therapeutic interventions in schizophrenia. PMID:27014035

  6. Organic transistor memory with a charge storage molecular double-floating-gate monolayer.

    PubMed

    Tseng, Chiao-Wei; Huang, Ding-Chi; Tao, Yu-Tai

    2015-05-13

    A flexible, low-voltage, and nonvolatile memory device was fabricated by implanting a functional monolayer on an aluminum oxide dielectric surface in a pentacene-based organic transistor. The monolayer-forming molecule contains a phosphonic acid group as the anchoring moiety and a charge-trapping core group flanked between two alkyl chain spacers as the charge trapping site. The memory characteristics strongly depend on the monolayer used due to the localized charge-trapping capability for different core groups, including the diacetylenic (DA) unit as the hole carrier trap, the naphthalenetetracarboxyldiimide (ND) unit as the electron carrier trap, and the one with both DA and ND units present, respectively. The device with the monolayer carrying both DA and ND groups has a larger memory window than that for the one containing DA only and a longer retention time than that for the one containing DA or ND only, giving a memory window of 1.4 V and a retention time around 10(9) s. This device with hybrid organic monolayer/inorganic dielectrics also exhibited rather stable device characteristics upon bending of the polymeric substrate. PMID:25875747

  7. Taking electrons out of bioelectronics: bioprotonic memories and enzymatic logic gates (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Rolandi, Marco

    2015-10-01

    In living systems, protonic and ionic currents are the basis for all information processing. As such, artificial devices based on protonic and ionic currents offer an exciting opportunity for bioelectronics. Proton transport in nature is important for ATP oxidative phosphorylation, the HCVN1 voltage gated proton channel, light activated proton pumping in bacteriorhodopsin, and the proton conducting single water file of the antibiotic gramicidin. In these systems, protons move along hydrogen bond networks formed by water and the hydrated biomolecules (proton wires). We have previously demonstrated complementary H+- and OH-- FETs with acid and base doped biopolymer proton wires and PdHx proton conducting contacts. Here, I will discuss proton-conducting devices based oh highly conductive proton wires that emulate brain synapses, display memristive behaviour, and are connected to form shift registries. Furthermore, I will present the integration of these devices with enzymatic logic gates for integrated biotic-abiotic protonic information processing. Preliminary results on using these devices to affect biological function will be discussed.

  8. Arousal Cues Arousal-Related Material in Memory: Implications for Understanding Effects of Mood on Memory.

    ERIC Educational Resources Information Center

    Clark, Margaret S.; And Others

    1983-01-01

    Discusses research showing that material people learn when in a high arousal state and material they learn when in a normal arousal state is subsequently best recalled when they are in a similar arousal state. Speculates that this effect may partially underlie mood cuing, mood-related material from memory. (EKN)

  9. Categorical and associative relations increase false memory relative to purely associative relations.

    PubMed

    Coane, Jennifer H; McBride, Dawn M; Termonen, Miia-Liisa; Cutting, J Cooper

    2016-01-01

    The goal of the present study was to examine the contributions of associative strength and similarity in terms of shared features to the production of false memories in the Deese/Roediger-McDermott list-learning paradigm. Whereas the activation/monitoring account suggests that false memories are driven by automatic associative activation from list items to nonpresented lures, combined with errors in source monitoring, other accounts (e.g., fuzzy trace theory, global-matching models) emphasize the importance of semantic-level similarity, and thus predict that shared features between list and lure items will increase false memory. Participants studied lists of nine items related to a nonpresented lure. Half of the lists consisted of items that were associated but did not share features with the lure, and the other half included items that were equally associated but also shared features with the lure (in many cases, these were taxonomically related items). The two types of lists were carefully matched in terms of a variety of lexical and semantic factors, and the same lures were used across list types. In two experiments, false recognition of the critical lures was greater following the study of lists that shared features with the critical lure, suggesting that similarity at a categorical or taxonomic level contributes to false memory above and beyond associative strength. We refer to this phenomenon as a "feature boost" that reflects additive effects of shared meaning and association strength and is generally consistent with accounts of false memory that have emphasized thematic or feature-level similarity among studied and nonstudied representations. PMID:26250805

  10. Life Experience with Death: Relation to Death Attitudes and to the Use of Death-Related Memories

    ERIC Educational Resources Information Center

    Bluck, Susan; Dirk, Judith; Mackay, Michael M.; Hux, Ashley

    2008-01-01

    The study examines the relation of death experience to death attitudes and to autobiographical memory use. Participants (N = 52) completed standard death attitude measures and wrote narratives about a death-related autobiographical memory and (for comparison) a memory of a low point. Self-ratings of the memory narratives were used to assess their…

  11. Spatial Relational Memory in 9-Month-Old Macaque Monkeys

    ERIC Educational Resources Information Center

    Lavenex, Pierre; Lavenex, Pamela Banta

    2006-01-01

    This experiment assesses spatial and nonspatial relational memory in freely moving 9-mo-old and adult (11-13-yr-old) macaque monkeys ("Macaca mulatta"). We tested the use of proximal landmarks, two different objects placed at the center of an open-field arena, as conditional cues allowing monkeys to predict the location of food rewards hidden in…

  12. Working Memory and Intelligence Are Highly Related Constructs, but Why?

    ERIC Educational Resources Information Center

    Colom, Roberto; Abad, Francisco J.; Quiroga, M. Angeles; Shih, Pei Chun; Flores-Mendoza, Carmen

    2008-01-01

    Working memory and the general factor of intelligence (g) are highly related constructs. However, we still don't know why. Some models support the central role of simple short-term storage, whereas others appeal to executive functions like the control of attention. Nevertheless, the available empirical evidence does not suffice to get an answer,…

  13. The Relations Among Abuse, Depression, and Adolescents' Autobiographical Memory

    ERIC Educational Resources Information Center

    Johnson, Rebecca J.; Greenhoot, Andrea Follmer; Glisky, Elizabeth; McCloskey, Laura A.

    2005-01-01

    This study examined the relations among early and recent experiences with abuse, depression, and adolescents' autobiographical memory in a longitudinal study of family violence. Participants' (N = 134) exposure to violence was documented when they were 6 to 12 years old and again when they were 12 to 18 years old. The second assessment included…

  14. The relationship between task-related and subsequent memory effects.

    PubMed

    de Chastelaine, Marianne; Rugg, Michael D

    2014-08-01

    The primary aim of this fMRI study was to assess the proposal that negative subsequent memory effects-greater activity for later forgotten relative to later remembered study items-are localized to regions demonstrating task-negative effects, and hence to potential components of the default mode network. Additionally, we assessed whether positive subsequent memory effects overlapped with regions demonstrating task-positive effects. Eighteen participants were scanned while they made easy or difficult relational judgments on visually presented word pairs. Easy and hard task blocks were interleaved with fixation-only rest periods. In the later unscanned test phase, associative recognition judgments were required on intact word pairs (studied pairs), rearranged pairs (pairs formed from words presented on different study trials) and new pairs. Subsequent memory effects were identified by contrasting the activity elicited by study pairs that went on to be correctly endorsed as intact versus incorrectly endorsed as rearranged. Task effects were identified by contrasting all study items and rest blocks. Both task-negative and task-positive effects were evident in widespread cortical regions and negative and positive subsequent memory effects were generally confined to task-negative and task-positive regions respectively. However, subsequent memory effects could be identified in only a fraction of task-sensitive voxels and, unlike task effects, were insensitive to the difficulty manipulation. The findings for the negative subsequent memory effects are consistent with recent proposals that the default mode network is functionally heterogeneous, and suggest that these effects are not accurately characterized as reflections of the modulation of the network as a whole. PMID:24615858

  15. Cerebrovascular Damage Mediates Relations Between Aortic Stiffness and Memory.

    PubMed

    Cooper, Leroy L; Woodard, Todd; Sigurdsson, Sigurdur; van Buchem, Mark A; Torjesen, Alyssa A; Inker, Lesley A; Aspelund, Thor; Eiriksdottir, Gudny; Harris, Tamara B; Gudnason, Vilmundur; Launer, Lenore J; Mitchell, Gary F

    2016-01-01

    Aortic stiffness is associated with cognitive decline. Here, we examined the association between carotid-femoral pulse wave velocity and cognitive function and investigated whether cerebrovascular remodeling and parenchymal small vessel disease damage mediate the relation. Analyses were based on 1820 (60% women) participants in the Age, Gene/Environment Susceptibility-Reykjavik Study. Multivariable linear regression models adjusted for vascular and demographic confounders showed that higher carotid-femoral pulse wave velocity was related to lower memory score (standardized β: -0.071±0.023; P=0.002). Cerebrovascular resistance and white matter hyperintensities were each associated with carotid-femoral pulse wave velocity and memory (P<0.05). Together, cerebrovascular resistance and white matter hyperintensities (total indirect effect: -0.029; 95% CI, -0.043 to -0.017) attenuated the direct relation between carotid-femoral pulse wave velocity and memory (direct effect: -0.042; 95% CI, -0.087 to 0.003; P=0.07) and explained ≈41% of the observed effect. Our results suggest that in older adults, associations between aortic stiffness and memory are mediated by pathways that include cerebral microvascular remodeling and microvascular parenchymal damage. PMID:26573713

  16. Memory for Items and Relationships among Items Embedded in Realistic Scenes: Disproportionate Relational Memory Impairments in Amnesia

    PubMed Central

    Hannula, Deborah E.; Tranel, Daniel; Allen, John S.; Kirchhoff, Brenda A.; Nickel, Allison E.; Cohen, Neal J.

    2014-01-01

    Objective The objective of this study was to examine the dependence of item memory and relational memory on medial temporal lobe (MTL) structures. Patients with amnesia, who either had extensive MTL damage or damage that was relatively restricted to the hippocampus, were tested, as was a matched comparison group. Disproportionate relational memory impairments were predicted for both patient groups, and those with extensive MTL damage were also expected to have impaired item memory. Method Participants studied scenes, and were tested with interleaved two-alternative forced-choice probe trials. Probe trials were either presented immediately after the corresponding study trial (lag 1), five trials later (lag 5), or nine trials later (lag 9) and consisted of the studied scene along with a manipulated version of that scene in which one item was replaced with a different exemplar (item memory test) or was moved to a new location (relational memory test). Participants were to identify the exact match of the studied scene. Results As predicted, patients were disproportionately impaired on the test of relational memory. Item memory performance was marginally poorer among patients with extensive MTL damage, but both groups were impaired relative to matched comparison participants. Impaired performance was evident at all lags, including the shortest possible lag (lag 1). Conclusions The results are consistent with the proposed role of the hippocampus in relational memory binding and representation, even at short delays, and suggest that the hippocampus may also contribute to successful item memory when items are embedded in complex scenes. PMID:25068665

  17. A 0.5-V Six-Transistor Static Random Access Memory with Ferroelectric-Gate Field Effect Transistors

    NASA Astrophysics Data System (ADS)

    Tanakamaru, Shuhei; Hatanaka, Teruyoshi; Yajima, Ryoji; Miyaji, Kousuke; Takahashi, Mitsue; Sakai, Shigeki; Takeuchi, Ken

    2010-12-01

    A 0.5 V six-transistor static random access memory (6T-SRAM) with ferroelectric-gate field-effect-transistors (Fe-FETs) is proposed and experimentally demonstrated for the first time. During the read and the hold, the threshold voltage (VTH) of Fe-FETs automatically changes to increase the static noise margin (SNM) by 60%. During the stand-by, the VTH of the proposed SRAM cell increases to decrease the leakage current by 42%. In case of the read, the VTH of the read transistor decreases and increases the cell read current to achieve the fast read. During the write, the VTH of the SRAM cell dynamically changes and assist the cell data to flip, realizing a write assist function. The enlarged SNM realizes the VDD reduction by 0.11 V, which decreases the active power by 32%. The proposed SRAM layout is the same as the conventional 6T-SRAM and there is no area penalty.

  18. Etiological Distinction of Working Memory Components in Relation to Mathematics

    PubMed Central

    Lukowski, Sarah L.; Soden, Brooke; Hart, Sara A.; Thompson, Lee A.; Kovas, Yulia; Petrill, Stephen A.

    2014-01-01

    Working memory has been consistently associated with mathematics achievement, although the etiology of these relations remains poorly understood. The present study examined the genetic and environmental underpinnings of math story problem solving, timed calculation, and untimed calculation alongside working memory components in 12-year-old monozygotic (n = 105) and same-sex dizygotic (n = 143) twin pairs. Results indicated significant phenotypic correlation between each working memory component and all mathematics outcomes (r = 0.18 – 0.33). Additive genetic influences shared between the visuo-spatial sketchpad and mathematics achievement was significant, accounting for roughly 89% of the observed correlation. In addition, genetic covariance was found between the phonological loop and math story problem solving. In contrast, despite there being a significant observed relationship between phonological loop and timed and untimed calculation, there was no significant genetic or environmental covariance between the phonological loop and timed or untimed calculation skills. Further analyses indicated that genetic overlap between the visuo-spatial sketchpad and math story problem solving and math fluency was distinct from general genetic factors, whereas g, phonological loop, and mathematics shared generalist genes. Thus, although each working memory component was related to mathematics, the etiology of their relationships may be distinct. PMID:25477699

  19. Screen memory: its importance to object relations and transference.

    PubMed

    Reichbart, Richard

    2008-06-01

    A screen memory of an obsessive and narcissistic man, reported early in psychoanalysis, both represented and disguised the patient's oedipal conflict, incestuous wishes, and sibling rivalry. It symbolized for him his relationship with his mother and was treated by him, in a repetitive and fetishistic manner throughout treatment, as the reason for his bitterness toward life, his sense of entitlement, his narcissism, and his distrust of women. In the transference, the memory-far from being inert- constantly played an active role in his wishes and disappointments regarding the analyst, and in his fantasied oedipal triumph over him. As the analysis progressed, and after years of treatment, the encapsulated nature of this memory began to give way to the patient's growing awareness of his oedipal wishes, the full range of his feelings toward his mother, and his sense of abandonment by her. The nature of screen memory is explored, including how it relates to a patient's personality and use of the past in general, how it may figure in the development of a person's object relations, and the decisive role it may play throughout a treatment. PMID:18515702

  20. Etiological Distinction of Working Memory Components in Relation to Mathematics.

    PubMed

    Lukowski, Sarah L; Soden, Brooke; Hart, Sara A; Thompson, Lee A; Kovas, Yulia; Petrill, Stephen A

    2014-11-01

    Working memory has been consistently associated with mathematics achievement, although the etiology of these relations remains poorly understood. The present study examined the genetic and environmental underpinnings of math story problem solving, timed calculation, and untimed calculation alongside working memory components in 12-year-old monozygotic (n = 105) and same-sex dizygotic (n = 143) twin pairs. Results indicated significant phenotypic correlation between each working memory component and all mathematics outcomes (r = 0.18 - 0.33). Additive genetic influences shared between the visuo-spatial sketchpad and mathematics achievement was significant, accounting for roughly 89% of the observed correlation. In addition, genetic covariance was found between the phonological loop and math story problem solving. In contrast, despite there being a significant observed relationship between phonological loop and timed and untimed calculation, there was no significant genetic or environmental covariance between the phonological loop and timed or untimed calculation skills. Further analyses indicated that genetic overlap between the visuo-spatial sketchpad and math story problem solving and math fluency was distinct from general genetic factors, whereas g, phonological loop, and mathematics shared generalist genes. Thus, although each working memory component was related to mathematics, the etiology of their relationships may be distinct. PMID:25477699

  1. Can DRYAD explain age-related associative memory deficits?

    PubMed

    Smyth, Andrea C; Naveh-Benjamin, Moshe

    2016-02-01

    A recent interesting theoretical account of aging and memory judgments, the DRYAD (density of representations yields age-related deficits; Benjamin, 2010; Benjamin, Diaz, Matzen, & Johnson, 2012), attributes the extensive findings of disproportional age-related deficits in memory for source, context, and associations, to a global decline in memory fidelity. It is suggested that this global deficit, possibly due to a decline in attentional processes, is moderated by weak representation of contextual information to result in disproportional age-related declines. In the current article, we evaluate the DRYAD model, comparing it to specific age-related deficits theories, in particular, the ADH (associative deficit hypothesis, Naveh-Benjamin, 2000). We question some of the main assumptions/hypotheses of DRYAD in light of data reported in the literature, and we directly assess the role of attention in age-related deficits by manipulations of divided attention and of the instructions regarding what to pay attention to in 2 experiments (one from the literature and a new one). The results of these experiments fit the predictions of the ADH and do not support the main assumption/hypotheses of DRYAD. PMID:25961878

  2. When memory meets beauty: Insights from event-related potentials.

    PubMed

    Marzi, T; Viggiano, M P

    2010-05-01

    Facial attractiveness plays a key role in human social and affective behavior. To study the time course of the neural processing of attractiveness and its influence on recognition memory we investigated the event-related potentials (ERPs) elicited in an old/new recognition task in response to faces with a neutral expression that, at encoding, were rated for their attractiveness. Highly attractive faces elicited a specific early positive-going component on frontal sites; in addition, with respect to less attractive faces, they elicited larger later components related to structural encoding and recognition memory. All in all, our results show that facial attractiveness, independently from facial expression, modulates face processing throughout all stages from encoding to retrieval. PMID:20109520

  3. 5 V driving organic non-volatile memory transistors with poly(vinyl alcohol) gate insulator and poly(3-hexylthiophene) channel layers

    NASA Astrophysics Data System (ADS)

    Nam, Sungho; Seo, Jooyeok; Kim, Hwajeong; Kim, Youngkyoo

    2015-10-01

    Organic non-volatile memory devices were fabricated by employing organic field-effect transistors (OFETs) with poly(vinyl alcohol) (PVA) and poly(3-hexylthiophene) as a gate insulating layer and a channel layer, respectively. The 10-nm-thick nickel layers were inserted for better charge injection between the channel layer and the top source/drain electrodes. The fabricated PVA-OFET memory devices could be operated at low voltages (≤5 V) and showed pronounced hysteresis characteristics in the transfer curves, even though very small hysteresis was measured from the output curves. The degree of hysteresis was considerably dependent on the ratio of channel width (W) to channel length (L). The PVA-OFET memory device with the smaller W/L ratio (25) exhibited better retention characteristics upon 700 cycles of writing-reading-erasing-reading operations, which was assigned to the stability of charged states in devices.

  4. A single poly-Si gate-all-around junctionless fin field-effect transistor for use in one-time programming nonvolatile memory

    PubMed Central

    2014-01-01

    This work demonstrates a feasible single poly-Si gate-all-around (GAA) junctionless fin field-effect transistor (JL-FinFET) for use in one-time programming (OTP) nonvolatile memory (NVM) applications. The advantages of this device include the simplicity of its use and the ease with which it can be embedded in Si wafer, glass, and flexible substrates. This device exhibits excellent retention, with a memory window maintained 2 V after 104 s. By extrapolation, 95% of the original charge can be stored for 10 years. In the future, this device will be applied to multi-layer Si ICs in fully functional systems on panels, active-matrix liquid-crystal displays, and three-dimensional (3D) stacked flash memory. PMID:25404873

  5. Olfactory memory in the old and very old: relations to episodic and semantic memory and APOE genotype.

    PubMed

    Larsson, Maria; Hedner, Margareta; Papenberg, Goran; Seubert, Janina; Bäckman, Lars; Laukka, Erika J

    2016-02-01

    The neuroanatomical organization that underlies olfactory memory is different from that of other memory types. The present work examines olfactory memory in an elderly population-based sample (Swedish National Study on Aging and Care in Kungsholmen) aged 60-100 years (n = 2280). We used structural equation modeling to investigate whether olfactory memory in old age is best conceptualized as a distinct category, differentiated from episodic and semantic memory. Further, potential olfactory dedifferentiation and genetic associations (APOE) to olfactory function in late senescence were investigated. Results are in support of a 3-factor solution where olfactory memory, as indexed by episodic odor recognition and odor identification, is modeled separately from episodic and semantic memory for visual and verbal information. Increasing age was associated with poorer olfactory memory performance, and observed age-related deficits were further exacerbated for carriers of the APOE ε4 allele; these effects tended to be larger for olfactory memory compared to episodic and semantic memory pertaining to other sensory systems (vision, auditory). Finally, stronger correlations between olfactory and episodic memory, indicating dedifferentiation, were observed in the older age groups. PMID:26827650

  6. Age-related differences in memory and in the memory effects of nootropic drugs.

    PubMed

    Petkov, V D; Mosharrof, A H; Petkov, V V; Kehayov, R A

    1990-01-01

    In experiments of 2-, 5-, 10- and 22-month old rats, using active avoidance with punishment reinforcement (maze and shuttle-box) and passive avoidance (step-down), we found that acquisition and retention in aged rats were impaired significantly or only as a trend. The nootropics adafenoxate, meclofenoxate, citicholine, aniracetam and the standardized ginseng extract administered orally for 7 to 10 days usually facilitated learning and improved memory in the rats of all ages. By some of the indices used the drugs gave more pronounced favourable effects in old rats, while by others better effects were observed in young or adult rats. The results demonstrate significant age-related differences in learning and memory in rats and in the effects of nootropic drugs on these processes. PMID:2281798

  7. Nonvolatile memory thin-film transistors using biodegradable chicken albumen gate insulator and oxide semiconductor channel on eco-friendly paper substrate.

    PubMed

    Kim, So-Jung; Jeon, Da-Bin; Park, Jung-Ho; Ryu, Min-Ki; Yang, Jong-Heon; Hwang, Chi-Sun; Kim, Gi-Heon; Yoon, Sung-Min

    2015-03-01

    Nonvolatile memory thin-film transistors (TFTs) fabricated on paper substrates were proposed as one of the eco-friendly electronic devices. The gate stack was composed of chicken albumen gate insulator and In-Ga-Zn-O semiconducting channel layers. All the fabrication processes were performed below 120 °C. To improve the process compatibility of the synthethic paper substrate, an Al2O3 thin film was introduced as adhesion and barrier layers by atomic layer deposition. The dielectric properties of biomaterial albumen gate insulator were also enhanced by the preparation of Al2O3 capping layer. The nonvolatile bistabilities were realized by the switching phenomena of residual polarization within the albumen thin film. The fabricated device exhibited a counterclockwise hysteresis with a memory window of 11.8 V, high on/off ratio of approximately 1.1 × 10(6), and high saturation mobility (μsat) of 11.5 cm(2)/(V s). Furthermore, these device characteristics were not markedly degraded even after the delamination and under the bending situration. When the curvature radius was set as 5.3 cm, the ION/IOFF ratio and μsat were obtained to be 5.9 × 10(6) and 7.9 cm(2)/(V s), respectively. PMID:25679117

  8. Medial temporal lobe viscoelasticity and relational memory performance.

    PubMed

    Schwarb, Hillary; Johnson, Curtis L; McGarry, Matthew D J; Cohen, Neal J

    2016-05-15

    Structural and functional imaging studies have been among converging lines of evidence demonstrating the importance of the hippocampus in successful memory performance. The advent of a novel neuroimaging technique - magnetic resonance elastography (MRE) - now makes it possible for us to investigate the relationship between the microstructural integrity of hippocampal tissue and successful memory processing. Mechanical properties of brain tissue estimated with MRE provide a measure of the integrity of the underlying tissue microstructure and have proven to be sensitive measures of tissue health in neurodegeneration. However, until recently, MRE methods lacked sufficient resolution necessary to accurately examine specific neuroanatomical structures in the brain, and thus could not contribute to examination of specific structure-function relationships. In this study, we took advantage of recent developments in MRE spatial resolution and mechanical inversion techniques to measure the viscoelastic properties of the human hippocampus in vivo, and investigated how these properties reflect hippocampal function. Our data reveal a strong relationship between relative elastic/viscous behavior of the hippocampus and relational memory performance (N=20). This is the first report linking the mechanical properties of brain tissue with functional performance. PMID:26931816

  9. Subjective aspects of working memory performance: memoranda-related imagery.

    PubMed

    Jantz, Tiffany K; Tomory, Jessica J; Merrick, Christina; Cooper, Shanna; Gazzaley, Adam; Morsella, Ezequiel

    2014-04-01

    Although it is well accepted that working memory (WM) is intimately related to consciousness, little research has illuminated the liaison between the two phenomena. To investigate this under-explored nexus, we used an imagery monitoring task to investigate the subjective aspects of WM performance. Specifically, in two experiments, we examined the effects on consciousness of (a) holding in mind information having a low versus high memory load, and (b) holding memoranda in mind during the presentation of distractors (e.g., visual stimuli associated with a response incompatible with that of the memoranda). Higher rates of rehearsal (conscious imagery) occurred in the high load and distractor conditions than in comparable control conditions. Examination of the temporal properties of the rehearsal-based imagery revealed that, across subjects, imagery events occurred evenly throughout the delay. We hope that future variants of this new imagery monitoring task will reveal additional insights about WM, consciousness, and action control. PMID:24583457

  10. Affective recognition memory processing and event-related brain potentials

    PubMed Central

    Kaestner, Erik J.

    2011-01-01

    Recognition memory was examined for visual affective stimuli using behavioral and event-related brain potential (ERP) measures. Images from the International Affective Picture System (IAPS) that varied systematically in arousal level (low, high) and valence direction (unpleasant, pleasant) were first viewed passively. Then, during a response phase, the original images were intermixed with an equal number of new images and presented, and participants were instructed to press a button to indicate whether each stimulus picture was previously viewed (target) or new (foil). Participants were more sensitive to unpleasant- than to pleasant-valence stimuli and were biased to respond to high-arousal unpleasant stimuli as targets, whether the stimuli were previously viewed or new. Response times (RTs) to target stimuli were systematically affected by valence, whereas RTs to foil stimuli were influenced by arousal level. ERP component amplitudes were generally larger for high than for low arousal levels. The P300 (late positive component) amplitude was largest for high-arousal unpleasant target images. These and other amplitude effects suggest that high-arousal unpleasant stimuli engage a privileged memory-processing route during stimulus processing. Theoretical relationships between affective and memory processes are discussed. PMID:21384231

  11. Cognitive Dissonance Resolution Is Related to Episodic Memory

    PubMed Central

    Maillet, Mathurin; Naccache, Lionel

    2014-01-01

    The notion that our past choices affect our future behavior is certainly one of the most influential concepts of social psychology since its first experimental report in the 50 s, and its initial theorization by Festinger within the “cognitive dissonance” framework. Using the free choice paradigm (FCP), it was shown that choosing between two similarly rated items made subjects reevaluate the chosen items as more attractive and the rejected items as less attractive. However, in 2010 a major work by Chen and Risen revealed a severe statistical flaw casting doubt on most previous studies. Izuma and colleagues (2010) supplemented the traditional FCP with original control conditions and concluded that the effect observed could not be solely attributed to this methodological flaw. In the present work we aimed at establishing the existence of genuine choice-induced preference change and characterizing this effect. To do so, we replicated Izuma et al.’ study and added a new important control condition which was absent from the original study. Moreover, we added a memory test in order to measure the possible relation between episodic memory of choices and observed behavioral effects. In two experiments we provide experimental evidence supporting genuine choice-induced preference change obtained with FCP. We also contribute to the understanding of the phenomenon by showing that choice-induced preference change effects are strongly correlated with episodic memory. PMID:25264950

  12. Cognitive dissonance resolution is related to episodic memory.

    PubMed

    Salti, Moti; El Karoui, Imen; Maillet, Mathurin; Naccache, Lionel

    2014-01-01

    The notion that our past choices affect our future behavior is certainly one of the most influential concepts of social psychology since its first experimental report in the 50 s, and its initial theorization by Festinger within the "cognitive dissonance" framework. Using the free choice paradigm (FCP), it was shown that choosing between two similarly rated items made subjects reevaluate the chosen items as more attractive and the rejected items as less attractive. However, in 2010 a major work by Chen and Risen revealed a severe statistical flaw casting doubt on most previous studies. Izuma and colleagues (2010) supplemented the traditional FCP with original control conditions and concluded that the effect observed could not be solely attributed to this methodological flaw. In the present work we aimed at establishing the existence of genuine choice-induced preference change and characterizing this effect. To do so, we replicated Izuma et al.' study and added a new important control condition which was absent from the original study. Moreover, we added a memory test in order to measure the possible relation between episodic memory of choices and observed behavioral effects. In two experiments we provide experimental evidence supporting genuine choice-induced preference change obtained with FCP. We also contribute to the understanding of the phenomenon by showing that choice-induced preference change effects are strongly correlated with episodic memory. PMID:25264950

  13. Is sleep-related verbal memory consolidation impaired in sleepwalkers?

    PubMed

    Uguccioni, Ginevra; Pallanca, Olivier; Golmard, Jean-Louis; Leu-Semenescu, Smaranda; Arnulf, Isabelle

    2015-04-01

    In order to evaluate verbal memory consolidation during sleep in subjects experiencing sleepwalking or sleep terror, 19 patients experiencing sleepwalking/sleep terror and 19 controls performed two verbal memory tasks (16-word list from the Free and Cued Selective Reminding Test, and a 220- and 263-word modified story recall test) in the evening, followed by nocturnal video polysomnography (n = 29) and morning recall (night-time consolidation after 14 h, n = 38). The following morning, they were given a daytime learning task using the modified story recall test in reverse order, followed by an evening recall test after 9 h of wakefulness (daytime consolidation, n = 38). The patients experiencing sleepwalking/sleep terror exhibited more frequent awakenings during slow-wave sleep and longer wakefulness after sleep onset than the controls. Despite this reduction in sleep quality among sleepwalking/sleep terror patients, they improved their scores on the verbal tests the morning after sleep compared with the previous evening (+16 ± 33%) equally well as the controls (+2 ± 13%). The performance of both groups worsened during the daytime in the absence of sleep (-16 ± 15% for the sleepwalking/sleep terror group and -14 ± 11% for the control group). There was no significant correlation between the rate of memory consolidation and any of the sleep measures. Seven patients experiencing sleepwalking also sleep-talked during slow-wave sleep, but their sentences were unrelated to the tests or the list of words learned during the evening. In conclusion, the alteration of slow-wave sleep during sleepwalking/sleep terror does not noticeably impact on sleep-related verbal memory consolidation. PMID:25212397

  14. Meaning-making in memories: a comparison of memories of death-related and low point life experiences.

    PubMed

    Mackay, Michael M; Bluck, Susan

    2010-09-01

    Because of their extensive experience with death and dying, hospice volunteers may be more successful at engaging in meaning-making regarding their death-related experiences than their low point life experiences (e.g., job loss). Consequently, their memories of death-related experiences will manifest more meaning-making strategies (e.g., bendfit-finding) than their low point memories. Fifty-two hospice volunteers wrote memory narratives of death-related and low point experiences and provided ratings of their memories. Results show that death memory narratives exhibit more meaning-making strategies, are rated as more emotionally positive, and are more frequently rehearsed. The long-term significance of the use of meaning-making strategies is discussed. PMID:24482847

  15. Ageing-related stereotypes in memory: When the beliefs come true.

    PubMed

    Bouazzaoui, Badiâa; Follenfant, Alice; Ric, François; Fay, Séverine; Croizet, Jean-Claude; Atzeni, Thierry; Taconnat, Laurence

    2016-05-01

    Age-related stereotype concerns culturally shared beliefs about the inevitable decline of memory with age. In this study, stereotype priming and stereotype threat manipulations were used to explore the impact of age-related stereotype on metamemory beliefs and episodic memory performance. Ninety-two older participants who reported the same perceived memory functioning were divided into two groups: a threatened group and a non-threatened group (control). First, the threatened group was primed with an ageing stereotype questionnaire. Then, both groups were administered memory complaints and memory self-efficacy questionnaires to measure metamemory beliefs. Finally, both groups were administered the Logical Memory task to measure episodic memory, for the threatened group the instructions were manipulated to enhance the stereotype threat. Results indicated that the threatened individuals reported more memory complaints and less memory efficacy, and had lower scores than the control group on the logical memory task. A multiple mediation analysis revealed that the stereotype threat effect on the episodic memory performance was mediated by both memory complaints and memory self-efficacy. This study revealed that stereotype threat impacts belief in one's own memory functioning, which in turn impairs episodic memory performance. PMID:26057336

  16. Awareness of Memory Ability and Change: (In)Accuracy of Memory Self-Assessments in Relation to Performance

    PubMed Central

    Rickenbach, Elizabeth Hahn; Agrigoroaei, Stefan; Lachman, Margie E.

    2015-01-01

    Little is known about subjective assessments of memory abilities and decline among middle-aged adults or their association with objective memory performance in the general population. In this study we examined self-ratings of memory ability and change in relation to episodic memory performance in two national samples of middle-aged and older adults from the Midlife in the United States study (MIDUS II in 2005-06) and the Health and Retirement Study (HRS; every two years from 2002 to 2012). MIDUS (Study 1) participants (N=3,581) rated their memory compared to others their age and to themselves five years ago; HRS (Study 2) participants (N=14,821) rated their current memory and their memory compared to two years ago, with up to six occasions of longitudinal data over ten years. In both studies, episodic memory performance was the total number of words recalled in immediate and delayed conditions. When controlling for demographic and health correlates, self-ratings of memory abilities, but not subjective change, were related to performance. We examined accuracy by comparing subjective and objective memory ability and change. More than one third of the participants across the studies had self-assessments that were inaccurate relative to their actual level of performance and change, and accuracy differed as a function of demographic and health factors. Further understanding of self-awareness of memory abilities and change beginning in midlife may be useful for identifying early warning signs of decline, with implications regarding policies and practice for early detection and treatment of cognitive impairment. PMID:25821529

  17. Death-Related versus Fond Memories of a Deceased Attachment Figure: Examining Emotional Arousal

    ERIC Educational Resources Information Center

    Rochman, Daniel

    2013-01-01

    Grieving is infused by memories and emotions. In this study, bereaved participants recalled either death-related or fond memories of their loved ones. Their emotional arousal was examined via physiologic and voice analytic measures. Both death-related and fond memories generated an acoustic profile indicative of sadness (reflected by voice quality…

  18. The Differential Relations between Verbal, Numerical and Spatial Working Memory Abilities and Children's Reading Comprehension

    ERIC Educational Resources Information Center

    Oakhill, Jane; Yuill, Nicola; Garnham, Alan

    2011-01-01

    Working memory predicts children's reading comprehension but it is not clear whether this relation is due to a modality-specific or general working memory. This study, which investigated the relations between children's reading skills and working memory (WM) abilities in 3 modalities, extends previous work by including measures of both reading…

  19. Decay of Iconic Memory Traces Is Related to Psychometric Intelligence: A Fixed-Links Modeling Approach

    ERIC Educational Resources Information Center

    Miller, Robert; Rammsayer, Thomas H.; Schweizer, Karl; Troche, Stefan J.

    2010-01-01

    Several memory processes have been examined regarding their relation to psychometric intelligence with the exception of sensory memory. This study examined the relation between decay of iconic memory traces, measured with a partial-report task, and psychometric intelligence, assessed with the Berlin Intelligence Structure test, in 111…

  20. Predicting fluctuations in widespread interest: memory decay and goal-related memory accessibility in internet search trends.

    PubMed

    Masicampo, E J; Ambady, Nalini

    2014-02-01

    Memory and interest respond in similar ways to people's shifting needs and motivations. We therefore tested whether memory and interest might produce similar, observable patterns in people's responses over time. Specifically, the present studies examined whether fluctuations in widespread interest (as measured by Internet search trends) resemble two well-established memory patterns: memory decay and goal-related memory accessibility. We examined national and international events (e.g., Nobel Prize selections, holidays) that produced spikes in widespread interest in certain people and foods. When the events that triggered widespread interest were incidental (e.g., the death of a celebrity), widespread interest conformed to memory decay patterns: It rose quickly, fell slowly according to a power function, and was higher after the event than before it. When the events that triggered widespread interest were goal related (e.g., political elections), widespread interest conformed to patterns of goal-related memory accessibility: It rose slowly, fell quickly according to a sigmoid function, and was lower after the event than before it. Fluctuations in widespread interest over time are thus similar to standard memory patterns observed at the individual level due perhaps to common mechanisms and functions. PMID:23127417

  1. Simulation of Nanoscale Two-Bit Not-And-type Silicon-Oxide-Nitride-Oxide-Silicon Nonvolatile Memory Devices with a Separated Double-Gate Fin Field Effect Transistor Structure Containing Different Tunneling Oxide Thicknesses

    NASA Astrophysics Data System (ADS)

    Oh, Se Woong; Park, Sang Su; Kim, Dong Hun; Kim, Hyun Woo; Kim, Tae Whan

    2009-06-01

    Not-and (NAND)-type silicon-oxide-nitride-oxide-silicon (SONOS) nonvolatile memory (NVM) devices with a separated double-gate (SDG) Fin field effect transistor structure were proposed to reduce the unit cell size of such memory devices and increase their memory density in comparison with that of conventional NVM devices. The proposed memory device consisted of a pair of control gates separated along the length of the Fin channel direction. Each SDG had a different thickness of the tunneling oxide to operate the proposed memory device as a two-bit/cell device. A technology computer-aided design simulation was performed to investigate the program/erase and two-bit characteristics. The simulation results show that the proposed devices can be used to increase the scaling down capability and charge storage density of NAND-type SONOS NVM devices.

  2. Alzheimer's disease and age-related memory decline (preclinical).

    PubMed

    Terry, Alvin V; Callahan, Patrick M; Hall, Brandon; Webster, Scott J

    2011-08-01

    An unfortunate result of the rapid rise in geriatric populations worldwide is the increasing prevalence of age-related cognitive disorders such as Alzheimer's disease (AD). AD is a devastating neurodegenerative illness that is characterized by a profound impairment of cognitive function, marked physical disability, and an enormous economic burden on the afflicted individual, caregivers, and society in general. The rise in elderly populations is also resulting in an increase in individuals with related (potentially treatable) conditions such as "Mild Cognitive Impairment" (MCI) which is characterized by a less severe (but abnormal) level of cognitive impairment and a high-risk for developing dementia. Even in the absence of a diagnosable disorder of cognition (e.g., AD and MCI), the perception of increased forgetfulness and declining mental function is a clear source of apprehension in the elderly. This is a valid concern given that even a modest impairment of cognitive function is likely to be associated with significant disability in a rapidly evolving, technology-based society. Unfortunately, the currently available therapies designed to improve cognition (i.e., for AD and other forms of dementia) are limited by modest efficacy and adverse side effects, and their effects on cognitive function are not sustained over time. Accordingly, it is incumbent on the scientific community to develop safer and more effective therapies that improve and/or sustain cognitive function in the elderly allowing them to remain mentally active and productive for as long as possible. As diagnostic criteria for memory disorders evolve, the demand for pro-cognitive therapeutic agents is likely to surpass AD and dementia to include MCI and potentially even less severe forms of memory decline. The purpose of this review is to provide an overview of the contemporary therapeutic targets and preclinical pharmacologic approaches (with representative drug examples) designed to enhance memory

  3. Logic gates realized by nonvolatile GeTe/Sb2Te3 super lattice phase-change memory with a magnetic field input

    NASA Astrophysics Data System (ADS)

    Lu, Bin; Cheng, Xiaomin; Feng, Jinlong; Guan, Xiawei; Miao, Xiangshui

    2016-07-01

    Nonvolatile memory devices or circuits that can implement both storage and calculation are a crucial requirement for the efficiency improvement of modern computer. In this work, we realize logic functions by using [GeTe/Sb2Te3]n super lattice phase change memory (PCM) cell in which higher threshold voltage is needed for phase change with a magnetic field applied. First, the [GeTe/Sb2Te3]n super lattice cells were fabricated and the R-V curve was measured. Then we designed the logic circuits with the super lattice PCM cell verified by HSPICE simulation and experiments. Seven basic logic functions are first demonstrated in this letter; then several multi-input logic gates are presented. The proposed logic devices offer the advantages of simple structures and low power consumption, indicating that the super lattice PCM has the potential in the future nonvolatile central processing unit design, facilitating the development of massive parallel computing architecture.

  4. Memory.

    ERIC Educational Resources Information Center

    McKean, Kevin

    1983-01-01

    Discusses current research (including that involving amnesiacs and snails) into the nature of the memory process, differentiating between and providing examples of "fact" memory and "skill" memory. Suggests that three brain parts (thalamus, fornix, mammilary body) are involved in the memory process. (JN)

  5. Integrative and semantic relations equally alleviate age-related associative memory deficits.

    PubMed

    Badham, Stephen P; Estes, Zachary; Maylor, Elizabeth A

    2012-03-01

    Two experiments compared effects of integrative and semantic relations between pairs of words on lexical and memory processes in old age. Integrative relations occur when two dissimilar and unassociated words are linked together to form a coherent phrase (e.g., horse-doctor). In Experiment 1, older adults completed a lexical-decision task where prime and target words were related either integratively or semantically. The two types of relation both facilitated responses compared to a baseline condition, demonstrating that priming can occur in older adults with minimal preexisting associations between primes and targets. In Experiment 2, young and older adults completed a cued recall task with integrative, semantic, and unrelated word pairs. Both integrative and semantic pairs showed significantly smaller age differences in associative memory compared to unrelated pairs. Integrative relations facilitated older adults' memory to a similar extent as semantic relations despite having few preexisting associations in memory. Integratability of stimuli is therefore a new factor that reduces associative deficits in older adults, most likely by supporting encoding and retrieval mechanisms. PMID:21639644

  6. Relation of Physical Activity to Memory Functioning in Older Adults: The Memory Workout Program.

    ERIC Educational Resources Information Center

    Rebok, George W.; Plude, Dana J.

    2001-01-01

    The Memory Workout, a CD-ROM program designed to help older adults increase changes in physical and cognitive activity influencing memory, was tested with 24 subjects. Results revealed a significant relationship between exercise time, exercise efficacy, and cognitive function, as well as interest in improving memory and physical activity.…

  7. Perceptual abnormalities related to sensory gating deficit are core symptoms in adults with ADHD.

    PubMed

    Micoulaud-Franchi, Jean-Arthur; Lopez, Régis; Vaillant, Florence; Richieri, Raphaëlle; El-Kaim, Alexandre; Bioulac, Stéphanie; Philip, Pierre; Boyer, Laurent; Lancon, Christophe

    2015-12-15

    This study investigated and compared perceptual abnormalities related to sensory gating deficit in adult patients with Attention Deficit Disorder with Hyperactivity (A-ADHD) and adult patients with schizophrenia. Subjects were evaluated with the Sensory Gating Inventory (SGI). We compared SGI scores between patients with A-ADHD, patients with schizophrenia and healthy subjects. We also assessed the relationship between SGI scores and clinical symptoms, and evaluated the ability of the SGI to detect perceptual abnormalities in A-ADHD. Seventy adult patients with ADHD reported higher SGI scores than the 70 healthy subjects and the 70 patients with schizophrenia. The inattention factor of the ASRS correlated significantly with the overall SGI score. The ROC AUC for the overall SGI score in the A-ADHD group (versus the healthy group) illustrated good performance. The findings suggest that i) perceptual abnormalities are core symptoms of adult patients with ADHD and ii) the attention of patients with A-ADHD may be involuntarily drowned by many irrelevant environmental stimuli leading to their impaired attention on relevant stimuli. They also confirm that the SGI could be a useful self-report instrument to diagnose the clinical features of A-ADHD. PMID:26416589

  8. Effect of ZnO channel thickness on the device behaviour of nonvolatile memory thin film transistors with double-layered gate insulators of Al2O3 and ferroelectric polymer

    NASA Astrophysics Data System (ADS)

    Yoon, Sung-Min; Yang, Shin-Hyuk; Park, Sang-Hee Ko; Jung, Soon-Won; Cho, Doo-Hee; Byun, Chun-Won; Kang, Seung-Youl; Hwang, Chi-Sun; Yu, Byoung-Gon

    2009-12-01

    Poly(vinylidene fluoride trifluoroethylene) and ZnO were employed for nonvolatile memory thin film transistors as ferroelectric gate insulator and oxide semiconducting channel layers, respectively. It was proposed that the thickness of the ZnO layer be carefully controlled for realizing the lower programming voltage, because the serially connected capacitor by the formation of a fully depleted ZnO channel had a critical effect on the off programming voltage. The fabricated memory transistor with Al/P(VDF-TrFE) (80 nm)/Al2O3 (4 nm)/ZnO (5 nm) exhibits encouraging behaviour such as a memory window of 3.8 V at the gate voltage of -10 to 12 V, and 107 on/off ratio, and a gate leakage current of 10-11 A.

  9. Young and Older Adults’ Beliefs about Effective Ways to Mitigate Age-Related Memory Decline

    PubMed Central

    Horhota, Michelle; Lineweaver, Tara; Ositelu, Monique; Summers, Kristi; Hertzog, Christopher

    2013-01-01

    This study investigated whether young and older adults vary in their beliefs about the impact of various mitigating factors on age-related memory decline. Eighty young (ages 18–23) and eighty older (ages 60–82) participants reported their beliefs about their own memory abilities and the strategies that they use in their everyday lives to attempt to control their memory. Participants also reported their beliefs about memory change with age for hypothetical target individuals who were described as using (or not using) various means to mitigate memory decline. There were no age differences in personal beliefs about control over current or future memory ability. However, the two age groups differed in the types of strategies they used in their everyday life to control their memory. Young adults were more likely to use internal memory strategies, whereas older adults were more likely to focus on cognitive exercise and maintaining physical health as ways to optimize their memory ability. There were no age differences in rated memory change across the life span in hypothetical individuals. Both young and older adults perceived strategies related to improving physical and cognitive health as effective means of mitigating memory loss with age, whereas internal memory strategies were perceived as less effective means for controlling age-related memory decline. PMID:22082012

  10. Entropic Uncertainty Relation and Information Exclusion Relation for multiple measurements in the presence of quantum memory

    NASA Astrophysics Data System (ADS)

    Zhang, Jun; Zhang, Yang; Yu, Chang-Shui

    2015-06-01

    The Heisenberg uncertainty principle shows that no one can specify the values of the non-commuting canonically conjugated variables simultaneously. However, the uncertainty relation is usually applied to two incompatible measurements. We present tighter bounds on both entropic uncertainty relation and information exclusion relation for multiple measurements in the presence of quantum memory. As applications, three incompatible measurements on Werner state and Horodecki’s bound entangled state are investigated in details.

  11. Entropic Uncertainty Relation and Information Exclusion Relation for multiple measurements in the presence of quantum memory.

    PubMed

    Zhang, Jun; Zhang, Yang; Yu, Chang-shui

    2015-01-01

    The Heisenberg uncertainty principle shows that no one can specify the values of the non-commuting canonically conjugated variables simultaneously. However, the uncertainty relation is usually applied to two incompatible measurements. We present tighter bounds on both entropic uncertainty relation and information exclusion relation for multiple measurements in the presence of quantum memory. As applications, three incompatible measurements on Werner state and Horodecki's bound entangled state are investigated in details. PMID:26118488

  12. Entropic Uncertainty Relation and Information Exclusion Relation for multiple measurements in the presence of quantum memory

    PubMed Central

    Zhang, Jun; Zhang, Yang; Yu, Chang-shui

    2015-01-01

    The Heisenberg uncertainty principle shows that no one can specify the values of the non-commuting canonically conjugated variables simultaneously. However, the uncertainty relation is usually applied to two incompatible measurements. We present tighter bounds on both entropic uncertainty relation and information exclusion relation for multiple measurements in the presence of quantum memory. As applications, three incompatible measurements on Werner state and Horodecki’s bound entangled state are investigated in details. PMID:26118488

  13. Repetition Priming in Adults with Williams Syndrome: Age-Related Dissociation between Implicit and Explicit Memory

    ERIC Educational Resources Information Center

    Krinsky-McHale, Sharon J.; Kittler, Phyllis; Brown, W. Ted; Jenkins, Edmund C.; Devenny, Darlynne A.

    2005-01-01

    We examined implicit and explicit memory in adults with Williams syndrome. An age-related dissociation was found; repetition priming (reflecting implicit memory) did not show change with age, but free recall (reflecting explicit memory) was markedly reduced. We also compared the performance of adults with Williams syndrome to adults with Down…

  14. Examining factors involved in stress-related working memory impairments: Independent or conditional effects?

    PubMed

    Banks, Jonathan B; Tartar, Jaime L; Tamayo, Brittney A

    2015-12-01

    A large and growing body of research demonstrates the impact of psychological stress on working memory. However, the typical study approach tests the effects of a single biological or psychological factor on changes in working memory. The current study attempted to move beyond the standard single-factor assessment by examining the impact of 2 possible factors in stress-related working memory impairments. To this end, 60 participants completed a working memory task before and after either a psychological stressor writing task or a control writing task and completed measures of both cortisol and mind wandering. We also included a measure of state anxiety to examine the direct and indirect effect on working memory. We found that mind wandering mediated the relationship between state anxiety and working memory at the baseline measurement. This indirect relationship was moderated by cortisol, such that the impact of mind wandering on working memory increased as cortisol levels increased. No overall working memory impairment was observed following the stress manipulation, but increases in state anxiety and mind wandering were observed. State anxiety and mind wandering independently mediated the relationship between change in working memory and threat perception. The indirect paths resulted in opposing effects on working memory. Combined, the findings from this study suggest that cortisol enhances the impact of mind wandering on working memory, that state anxiety may not always result in stress-related working memory impairments, and that high working memory performance can protect against mind wandering. PMID:26098727

  15. Respiratory sensory gating measured by respiratory-related evoked potentials in generalized anxiety disorder

    PubMed Central

    Chan, Pei-Ying S.; Cheng, Chia-Hsiung; Hsu, Shih-Chieh; Liu, Chia-Yih; Davenport, Paul W.; von Leupoldt, Andreas

    2015-01-01

    The perception of respiratory sensations plays an important role both in respiratory diseases and in anxiety disorders. However, little is known about the neural processes underlying respiratory sensory perception, especially in patient groups. Therefore, the present study examined whether patients with generalized anxiety disorder (GAD) would demonstrate altered respiratory sensory gating compared to a healthy control group. Respiratory-related evoked potentials (RREP) were measured in a paired inspiratory occlusion paradigm presenting two brief occlusion stimuli (S1 and S2) within one inspiration. The results showed a significantly greater S2/S1 ratio for the N1 component of the RREP in the GAD group compared to the control group. Our findings suggest altered respiratory sensory processing in patients with GAD, which might contribute to altered perception of respiratory sensations in these patients. PMID:26217278

  16. Neuroanatomical Correlates of Malingered Memory Impairment: Event-related fMRI of Deception on a Recognition Memory Task

    PubMed Central

    Browndyke, Jeffrey N.; Paskavitz, James; Sweet, Lawrence H.; Cohen, Ronald A.; Tucker, Karen A.; Welsh-Bohmer, Kathleen A.; Burke, James R.; Schmechel, Donald E.

    2010-01-01

    Primary objective Event-related, functional magnetic resonance imaging (fMRI) data were acquired in healthy participants during purposefully malingered and normal recognition memory performances to evaluate the neural substrates of feigned memory impairment. Methods and procedures Pairwise, between-condition contrasts of neural activity associated with discrete recognition memory responses were conducted to isolate dissociable neural activity between normal and malingered responding while simultaneously controlling for shared stimulus familiarity and novelty effects. Response timing characteristics were also examined for any association with observed between-condition activity differences. Outcomes and results Malingered recognition memory errors, regardless of type, were associated with inferior parietal and superior temporal activity relative to normal performance, while feigned recognition target misses produced additional dorsomedial frontal activation and feigned foil false alarms activated bilateral ventrolateral frontal regions. Malingered response times were associated with activity in the dorsomedial frontal, temporal, and inferior parietal regions. Normal memory responses were associated with greater inferior occipitotemporal and dorsomedial parietal activity, suggesting greater reliance upon visual/attentional networks for proper task performance. Conclusions The neural substrates subserving feigned recognition memory deficits are influenced by response demand and error type, producing differential activation of cortical regions important to complex visual processing, executive control, response planning, and working memory processes. PMID:18465389

  17. Relations between Vocabulary Development and Verbal Short-Term Memory: The Relative Importance of Short-Term Memory for Serial Order and Item Information

    ERIC Educational Resources Information Center

    Majerus, Steve; Poncelet, Martine; Greffe, Christelle; Van der Linden, Martial

    2006-01-01

    Although many studies have shown an association between verbal short-term memory (STM) and vocabulary development, the precise nature of this association is not yet clear. The current study reexamined this relation in 4- to 6-year-olds by designing verbal STM tasks that maximized memory for either item or serial order information. Although…

  18. Memory strategy training in children with cerebral infarcts related to sickle cell disease.

    PubMed

    Yerys, Benjamin E; White, Desirée A; Salorio, Cynthia F; McKinstry, Robert; Moinuddin, Asif; DeBaun, Michael

    2003-06-01

    Cerebral infarcts occur in approximately 30% of children with sickle cell disease (SCD), but little information exists regarding remediation of associated cognitive deficits. The authors examined the benefits of training children with infarcts to use memory strategies. Six children with SCD-related infarcts received academic tutoring; three of these children received additional training in memory strategies (silent rehearsal to facilitate short-term memory and semantic organization to facilitate long-term memory). The performance of children receiving strategy training appeared to improve more than that of children receiving only tutoring. Memory in children with SCD-related infarcts may be enhanced through strategy training. PMID:12794531

  19. The Relations between Early Working Memory Abilities and Later Developing Reading Skills: A Longitudinal Study from Kindergarten to Fifth Grade

    ERIC Educational Resources Information Center

    Nevo, Einat; Bar-Kochva, Irit

    2015-01-01

    This study investigated the relations of early working-memory abilities (phonological and visual-spatial short-term memory [STM] and complex memory and episodic buffer memory) and later developing reading skills. Sixty Hebrew-speaking children were followed from kindergarten through Grade 5. Working memory was tested in kindergarten and reading in…

  20. Effect of the chemical composition at the memory behavior of Al/BST/SiO2/Si-gate-FET structure

    NASA Astrophysics Data System (ADS)

    Saif, Ala'eddin A.; Jamal, Z. A. Z.; Poopalan, P.

    2011-09-01

    The effect of the chemical composition of the ferroelectric barium strontium titanate (BST) on the memory window behavior of Al/BST/SiO2/Si-gate-field effect transistor structure has been investigated. Nanocrystalline Ba x Sr1- x TiO3 thin films with different x values have been fabricated as metal-ferroelectric-insulator-semiconductor (MFIS) and metal-ferroelectric-metal (MFM) configurations using a sol-gel technique. The variation of the dielectric constant (ɛ) and tan δ with frequency for MFM samples have been studied to ensure the dielectric quality of the material. At low frequencies, ɛ increases as the strontium content decreases, whereas at high frequencies, it shows the opposite variation, which is attributed to the dipole dynamics. The ferroelectricity of the BST within MFM structure has been investigated using C-V characteristics, which show that the ferroelectric hysteresis strength increases as the strontium content decreases. The ferroelectric memory behavior of the MFIS samples has been investigated using C-V characteristics. The results show that the memory window width increases as the strontium content decreases; this is attributed to the grain size and dipole dynamics effect.

  1. Investing the effectiveness of retention performance in a non-volatile floating gate memory device with a core-shell structure of CdSe nanoparticles

    NASA Astrophysics Data System (ADS)

    Lee, Dong-Hoon; Kim, Jung-Min; Lim, Ki-Tae; Cho, Hyeong Jun; Bang, Jin Ho; Kim, Yong-Sang

    2016-03-01

    In this paper, we empirically investigate the retention performance of organic non-volatile floating gate memory devices with CdSe nanoparticles (NPs) as charge trapping elements. Core-structured CdSe NPs or core-shell-structured ZnS/CdSe NPs were mixed in PMMA and their performance in pentacene based device was compared. The NPs and self-organized thin tunneling PMMA inside the devices exhibited hysteresis by trapping hole during capacitance-voltage characterization. Despite of core-structured NPs showing a larger memory window, the retention time was too short to be adopted by an industry. By contrast core-shell structured NPs showed an improved retention time of >10000 seconds than core-structure NCs. Based on these results and the energy band structure, we propose the retention mechanism of each NPs. This investigation of retention performance provides a comparative and systematic study of the charging/discharging behaviors of NPs based memory devices. [Figure not available: see fulltext.

  2. Study of Novel Floating-Gate Oxide Semiconductor Memory Using Indium-Gallium-Zinc Oxide for Low-Power System-on-Panel Applications

    NASA Astrophysics Data System (ADS)

    Yamauchi, Yoshimitsu; Kamakura, Yoshinari; Isagi, Yousuke; Matsuoka, Toshimasa; Malotaux, Satoshi

    2013-09-01

    A novel floating-gate oxide semiconductor (FLOTOS) memory using a wide-band-gap indium-gallium-zinc oxide (IGZO) is presented for low-power system-on-panel applications. An IGZO thin-film-transistor (TFT) is used as a memory transistor for controlling read current as well as a switching transistor for storing charges in a storage capacitor (Cs). The FLOTOS memory is fabricated using a standard IGZO TFT process without any additional process or mask steps. The proposed precharge-assisted threshold voltage compensation technique makes it possible to realize an infinite number of write cycles and a low-power write operation with a bit-line voltage of 5 V. Furthermore, excellent data retention longer than 10 h is obtained at 60 °C even under the worst bias-stress condition of read operation with the ultra low off-state leakage (2.8×10-20 A/µm) of the IGZO TFTs, which is estimated to be smaller by more than 7 orders of magnitude than that of polycrystalline silicon TFTs.

  3. Hippocampal representation of related and opposing memories develop within distinct, hierarchically organized neural schemas.

    PubMed

    McKenzie, Sam; Frank, Andrea J; Kinsky, Nathaniel R; Porter, Blake; Rivière, Pamela D; Eichenbaum, Howard

    2014-07-01

    Recent evidence suggests that the hippocampus may integrate overlapping memories into relational representations, or schemas, that link indirectly related events and support flexible memory expression. Here we explored the nature of hippocampal neural population representations for multiple features of events and the locations and contexts in which they occurred. Hippocampal networks developed hierarchical organizations of associated elements of related but separately acquired memories within a context, and distinct organizations for memories where the contexts differentiated object-reward associations. These findings reveal neural mechanisms for the development and organization of relational representations. PMID:24910078

  4. Age-related differences in working memory updating components.

    PubMed

    Linares, Rocío; Bajo, M Teresa; Pelegrina, Santiago

    2016-07-01

    The aim of this study was to investigate possible age-related changes throughout childhood and adolescence in different component processes of working memory updating (WMU): retrieval, transformation, and substitution. A set of numerical WMU tasks was administered to four age groups (8-, 11-, 14-, and 21-year-olds). To isolate the effect of each of the WMU components, participants performed different versions of a task that included different combinations of the WMU components. The results showed an expected overall decrease in response times and an increase in accuracy performance with age. Most important, specific age-related changes in the retrieval component were found, demonstrating that the effect of retrieval on accuracy was larger in children than in adolescents or young adults. These findings indicate that the availability of representations from outside the focus of attention may change with age. Thus, the retrieval component of updating could contribute to the age-related changes observed in the performance of many updating tasks. PMID:26985577

  5. Are Memory Self-Efficacy and Memory Performance Related? A Meta-Analysis

    ERIC Educational Resources Information Center

    Beaudoin, Marine; Desrichard, Olivier

    2011-01-01

    The association between memory self-efficacy (MSE) and memory performance is highly documented in the literature. However, previous studies have produced inconsistent results, and there is no consensus on the existence of a significant link between these two variables. In order to evaluate whether or not the effect size of the MSE-memory…

  6. Working Memory, Animacy, and Verb Class in the Processing of Relative Clauses

    ERIC Educational Resources Information Center

    Traxler, M.J.; Williams, R.S.; Blozis, S.A.; Morris, R.K.

    2005-01-01

    In three eye-movement monitoring experiments, participants' working memory capacity was assessed and they read sentences containing subject-extracted and object-extracted relative clauses. In Experiment 1, sentences lacked helpful semantic cues, object-relatives were harder to process than subject relatives, and working memory capacity did not…

  7. College students' memory for vocabulary in their majors: evidence for a nonlinear relation between knowledge and memory.

    PubMed

    DeMarie, Darlene; Aloise-Young, Patricia A; Prideaux, Cheri L; Muransky-Doran, Jean; Gerda, Julie Hart

    2004-09-01

    The effect of domain knowledge on students' memory for vocabulary terms was investigated. Participants were 142 college students (94 education majors and 48 business majors). The measure of domain knowledge was the number of courses completed in the major. Students recalled three different lists (control, education, and business) of 20 words. Knowledge effects were estimated controlling for academic aptitude, academic achievement, and general memory ability. Domain-specific knowledge consistently predicted recall, above and beyond the effect of these control variables. Moreover, nonlinear models better represented the relation between knowledge and memory, with very similar functions predicting recall in both knowledge domains. Specifically, early in the majors more classes corresponded with increased memory performance, but a plateau period, when more classes did not result in higher recall, was evident for both majors. Longitudinal research is needed to explore at what point in learning novices' performance begins to resemble experts' performance. PMID:15487438

  8. Goal orientation and self-efficacy in relation to memory in adulthood.

    PubMed

    Hastings, Erin C; West, Robin L

    2011-07-01

    The achievement goal framework (Dweck, 1986, American Psychologist, 41, 1040) has been well-established in children and college-students, but has rarely been examined empirically with older adults. The current study, including younger and older adults, examined the effects of memory self-efficacy, learning goals (focusing on skill mastery over time) and performance goals (focusing on performance outcome evaluations) on memory performance. Questionnaires measured memory self-efficacy and general orientation toward learning and performance goals; free and cued recall was assessed in a subsequent telephone interview. As expected, age was negatively related and education was positively related to memory self-efficacy, and memory self-efficacy was positively related to memory, in a structural equation model. Age was also negatively related to memory performance. Results supported the positive impact of learning goals and the negative impact of performance goals on memory self-efficacy. There was no significant direct effect of learning or performance goals on memory performance; their impact occurred via their effect on memory self-efficacy. The present study supports past research suggesting that learning goals are beneficial, and performance goals are maladaptive, for self-efficacy and learning, and validates the achievement goal framework in a sample including older adults. PMID:21728891

  9. Goal orientation and self-efficacy in relation to memory in adulthood

    PubMed Central

    Hastings, Erin C.; West, Robin L.

    2011-01-01

    The achievement goal framework (Dweck, 1986) has been well-established in children and college-students, but has rarely been examined empirically with older adults. The current study, including younger and older adults, examined the effects of memory self-efficacy, learning goals (focusing on skill mastery over time) and performance goals (focusing on performance outcome evaluations) on memory performance. Questionnaires measured memory self-efficacy and general orientation toward learning and performance goals; free and cued recall was assessed in a subsequent telephone interview. As expected, age was negatively related and education was positively related to memory self-efficacy, and memory self-efficacy was positively related to memory, in a structural equation model. Age was also negatively related to memory performance. Results supported the positive impact of learning goals and the negative impact of performance goals on memory self-efficacy. There was no significant direct effect of learning or performance goals on memory performance; their impact occurred via their effect on memory self-efficacy. The present study supports past research suggesting that learning goals are beneficial, and performance goals are maladaptive, for self-efficacy and learning, and validates the achievement goal framework in a sample including older adults. PMID:21728891

  10. Surface photovoltage analysis of iron contamination in silicon processing and the relation to gate oxide integrity

    NASA Astrophysics Data System (ADS)

    Henley, Worth B.

    1995-09-01

    Surface photovoltage (SPV), a contactless optical technique for measuring minority carrier lifetime, is used to quantify the relationship between silicon iron contamination level and thin gate oxide integrity. Iron concentration levels in the range of 1 X 1010 cm-3 to 5 X 1013 cm-3 are evaluated for oxide thicknesses of 8 to 20 nm. Ramp voltage electrical breakdown and time dependant dielectric breakdown measurement on the iron contaminated gate oxide capacitors are reported. Distinct iron contamination threshold limits based on defect density and gate oxide integrity evaluate cleaning efficiencies and metallic cross contamination effects during thermal processing contamination. Iron-silicide precipitation kinetics are investigated by the lifetime analysis procedure.

  11. Meaning-Making in Memories: A Comparison of Memories of Death-Related and Low Point Life Experiences

    ERIC Educational Resources Information Center

    Mackay, Michael M.; Bluck, Susan

    2010-01-01

    Because of their extensive experience with death and dying, hospice volunteers may be more successful at engaging in meaning-making regarding their death-related experiences than their low point life experiences (e.g., job loss). Consequently, their memories of death-related experiences will manifest more meaning-making strategies (e.g.,…

  12. Control gate length, spacing, channel hole diameter, and stacked layer number design for bit-cost scalable-type three-dimensional stackable NAND flash memory

    NASA Astrophysics Data System (ADS)

    Miyaji, Kousuke; Yanagihara, Yuki; Hirasawa, Reo; Ning, Sheyang; Takeuchi, Ken

    2014-02-01

    A cell design for three-dimensional (3D) stackable NAND (3D NAND) flash memory are investigated with emphases on control gate length (Lg), spacing (Lspace) and channel hole diameter (Φ). The requirements for the Lg and Lspace are derived from the 3D device simulation and the effective cell size that competes with the planar NAND. The simulations reveal that Lg = Lspace = 20 nm (40 nm layer pitch) is achievable for bit-cost scalable (BiCS)-type 3D NAND with the 90 nm diameter hole. If the number of stacked layers is 22 with the layer pitch of 40 nm, the effective cell size of the 3D NAND corresponds to that of 15 nm planar NAND technology. Furthermore, cell characteristics of the macaroni body channel with various Φ are investigated. Although macaroni body channel improves cell characteristics at Φ = 90 nm, a cell with Φ = 60 nm without macaroni body structure shows better characteristics.

  13. Residual Clamping Force and Dynamic Random Access Memory Data Retention Improved by Gate Tungsten Etch Dechucking Condition in a Bipolar Electrostatic Chuck

    NASA Astrophysics Data System (ADS)

    Lee, Chung-Yuan; Lai, Chao-Sung; Yang, Chia-Ming; Wang, David HL; Lin, Betty; Lee, Siimon; Huang, Chi-Hung; Wei, Chen Chang

    2012-08-01

    It was found that the residual clamping force of bipolar electrostatic chucks created by the residual charge between a wafer and an electrode would not only cause a wafer sticking problem but also degrade dynamic random access memory (DRAM) data retention performance. The residual clamping force and data retention fail bit count (FBC) of DRAM showed strong correlations to the gate tungsten etch dechucking process condition. Wafer sticking only degraded DRAM cell retention performance, and did not influence any in-line measurement or electrical parameters. Electrical characterization analysis of the FBC proved that the retention loss was mainly due to junction leakage rather than gate-induced-drain-leakage current. A new approach was proposed to suppress this leakage by introducing N2 gas instead of O2 to supply more plasma charges for neutralizing the wafer surface residual charges. The wafer shift dynamic alignment (DA) offset and retention FBC could be reduced by 50 and 40%, respectively. Poor data retention was suspected because of the compressive stress caused by wafer sticking DA shift resulting in a high electric field at the junction and an increase in junction leakage at the storage node.

  14. Relative recency influences object-in-context memory

    PubMed Central

    Tam, Shu K.E.; Bonardi, Charlotte; Robinson, Jasper

    2015-01-01

    In two experiments rats received training on an object-in-context (OIC) task, in which they received preexposure to object A in context x, followed by exposure to object B in context y. In a subsequent test both A and B are presented in either context x or context y. Usually more exploration is seen of the object that has not previously been paired with the test context, an effect attributed to the ability to remember where an object was encountered. However, in the typical version of this task, object A has also been encountered less recently than object B at test. This is precisely the arrangement in tests of ‘relatively recency’ (RR), in which more remotely presented objects are explored more than objects experienced more recently. RR could contaminate performance on the OIC task, by enhancing the OIC effect when animals are tested in context y, and masking it when the test is in context x. This possibility was examined in two experiments, and evidence for superior performance in context y was obtained. The implications of this for theoretical interpretations of recognition memory and the procedures used to explore it are discussed. PMID:25546721

  15. Relative recency influences object-in-context memory.

    PubMed

    Tam, Shu K E; Bonardi, Charlotte; Robinson, Jasper

    2015-03-15

    In two experiments rats received training on an object-in-context (OIC) task, in which they received preexposure to object A in context x, followed by exposure to object B in context y. In a subsequent test both A and B are presented in either context x or context y. Usually more exploration is seen of the object that has not previously been paired with the test context, an effect attributed to the ability to remember where an object was encountered. However, in the typical version of this task, object A has also been encountered less recently than object B at test. This is precisely the arrangement in tests of 'relatively recency' (RR), in which more remotely presented objects are explored more than objects experienced more recently. RR could contaminate performance on the OIC task, by enhancing the OIC effect when animals are tested in context y, and masking it when the test is in context x. This possibility was examined in two experiments, and evidence for superior performance in context y was obtained. The implications of this for theoretical interpretations of recognition memory and the procedures used to explore it are discussed. PMID:25546721

  16. Relation of Three Mechanisms of Working Memory to Children's Complex Span Performance

    ERIC Educational Resources Information Center

    Magimairaj, Beula; Montgomery, James; Marinellie, Sally; McCarthy, John

    2009-01-01

    There is a paucity of research examining the relative contribution of the different mechanisms of working memory (short-term storage [STM], processing speed) to children's complex memory span. This study served to replicate and extend the few extant studies that have examined the issue. In this study, the relative contribution of three mechanisms…

  17. Mechanisms of Age-Related Decline in Memory Search across the Adult Life Span

    ERIC Educational Resources Information Center

    Hills, Thomas T.; Mata, Rui; Wilke, Andreas; Samanez-Larkin, Gregory R.

    2013-01-01

    Three alternative mechanisms for age-related decline in memory search have been proposed, which result from either reduced processing speed (global slowing hypothesis), overpersistence on categories (cluster-switching hypothesis), or the inability to maintain focus on local cues related to a decline in working memory (cue-maintenance hypothesis).…

  18. Dietary lipids are differentially associated with hippocampal-dependent relational memory in prepubescent children1234

    PubMed Central

    Khan, Naiman A; Monti, Jim M; Raine, Lauren B; Drollette, Eric S; Moore, R Davis; Scudder, Mark R; Kramer, Arthur F; Hillman, Charles H; Cohen, Neal J

    2014-01-01

    Background: Studies in rodents and older humans have shown that the hippocampus—a brain structure critical to relational/associative memory—has remarkable plasticity as a result of lifestyle factors (eg, exercise). However, the effect of dietary intake on hippocampal-dependent memory during childhood has remained unexamined. Objective: We investigated the cross-sectional relation of dietary components characteristic of the Western diet, including saturated fatty acids (SFAs), omega-3 (n−3) fatty acids, and refined sugar, with hippocampal-dependent relational memory in prepubescent children. Design: Participants aged 7–9 y (n = 52) reported their dietary intake by using the Youth-Adolescent Food-Frequency Questionnaire and completed memory tasks designed to assess relational (hippocampal-dependent) and item (hippocampal-independent) memory. Performance on the memory tasks was assessed with both direct (accuracy) and indirect (eye movement) measures. Results: Partial correlations adjusted for body mass index showed a positive relation between relational memory accuracy and intake of omega-3 fatty acids and a negative relation of both relational and item memory accuracy with intake of SFAs. Potential confounding factors of age, sex, intelligence quotient, socioeconomic status, pubertal timing, and aerobic fitness (maximal oxygen volume) were not significantly related to any of the dietary intake measures. Eye movement measures of relational memory (preferential viewing to the target stimulus) showed a negative relation with intake of added sugar. Conclusions: SFA intake was negatively associated with both forms of memory, whereas omega-3 fatty acid intake was selectively positively associated with hippocampal-dependent relational memory. These findings are among the first to show a link between habitual dietary intake and cognitive health as pertaining to hippocampal function in childhood. The Fitness Improves Thinking Kids (FITKids) and FITKids2 trials were

  19. Modifying Memory for a Museum Tour in Older Adults: Reactivation-Related Updating that Enhances and Distorts Memory is Reduced in Aging

    PubMed Central

    St Jacques, Peggy L.; Montgomery, Daniel; Schacter, Daniel L.

    2015-01-01

    Memory reactivation, the activation of a latent memory trace when we are reminded of a past experience, strengthens memory but can also contribute to distortions if new information present during reactivation is integrated with existing memory. In a previous study in young adults we found that the quality of memory reactivation, manipulated using the principle of encoding specificity and indexed by recollection ratings, modulated subsequent true and false memories for events experienced during a museum tour. Here, we examined age-related changes in the quality of memory reactivation on subsequent memory. Young and older adults reactivated memories for museum stops immediately followed by the presentation of a novel lure photo from an alternate tour version (i.e., reactivation plus new information). There was an increase in subsequent true memories for reactivated targets and for subsequent false memories for lures that followed reactivated targets, when compared to baseline target and lure photos. However, the influence of reactivation on subsequent memories was reduced in older adults. These data reveal that aging alters reactivation-related updating processes that allow memories to be strengthened and updated with new information-consequently reducing memory distortions in older compared to young adults. PMID:24993055

  20. An age-related deficit in spatial-feature reference memory in homing pigeons (Columba livia).

    PubMed

    Coppola, Vincent J; Flaim, Mary E; Carney, Samantha N; Bingman, Verner P

    2015-03-01

    Age-related memory decline in mammals has been well documented. By contrast, very little is known about memory decline in birds as they age. In the current study we trained younger and older homing pigeons on a reference memory task in which a goal location could be encoded by spatial and feature cues. Consistent with a previous working memory study, the results revealed impaired acquisition of combined spatial-feature reference memory in older compared to younger pigeons. Following memory acquisition, we used cue-conflict probe trials to provide an initial assessment of possible age-related differences in cue preference. Both younger and older pigeons displayed a similarly modest preference for feature over spatial cues. PMID:25449841

  1. Systems and methods for detecting a failure event in a field programmable gate array

    NASA Technical Reports Server (NTRS)

    Ng, Tak-Kwong (Inventor); Herath, Jeffrey A. (Inventor)

    2009-01-01

    An embodiment generally relates to a method of self-detecting an error in a field programmable gate array (FPGA). The method includes writing a signature value into a signature memory in the FPGA and determining a conclusion of a configuration refresh operation in the FPGA. The method also includes reading an outcome value from the signature memory.

  2. Central Adiposity is Negatively Associated with Hippocampal-Dependent Relational Memory among Overweight and Obese Children

    PubMed Central

    Khan, Naiman A.; Baym, Carol L.; Monti, Jim M.; Raine, Lauren B.; Drollette, Eric S.; Scudder, Mark R.; Moore, R. Davis; Kramer, Arthur F.; Hillman, Charles H.; Cohen, Neal J.

    2014-01-01

    Objective To assess associations between adiposity and hippocampal-dependent and hippocampal-independent memory forms among prepubertal children. Study design Prepubertal children (7–9-year-olds, n = 126), classified as non-overweight (<85th %tile BMI-for-age [n = 73]) or overweight/obese (≥85th %tile BMI-for-age [n = 53]), completed relational (hippocampal-dependent) and item (hippocampal-independent) memory tasks, and performance was assessed with both direct (behavioral accuracy) and indirect (preferential disproportionate viewing [PDV]) measures. Adiposity (%whole body fat mass, subcutaneous abdominal adipose tissue, visceral adipose tissue, and total abdominal adipose tissue) was assessed using DXA. Backward regressions identified significant (P <0.05) predictive models of memory performance. Covariates included age, sex, pubertal timing, socioeconomic status, IQ, oxygen consumption (VO2max), and body mass index (BMI) z-score. Results Among overweight/obese children, total abdominal adipose tissue was a significant negative predictor of relational memory behavioral accuracy, and pubertal timing together with socioeconomic status jointly predicted the PDV measure of relational memory. In contrast, among non-overweight children, male sex predicted item memory behavioral accuracy, and a model consisting of socioeconomic status and BMI z-score jointly predicted the PDV measure of relational memory. Conclusions Regional, and not whole body, fat deposition was selectively and negatively associated with hippocampal-dependent relational memory among overweight/obese prepubertal children. PMID:25454939

  3. Working memory maintenance contributes to long-term memory formation: evidence from slow event-related brain potentials.

    PubMed

    Khader, Patrick; Ranganath, Charan; Seemüller, Anna; Rösler, Frank

    2007-09-01

    Behavioral research has led to conflicting views regarding the relationship between working memory (WM) maintenance and long-term memory (LTM) formation. We used slow event-related brain potentials to investigate the degree to which neural activity during WM maintenance is associated with successful LTM formation. Participants performed a WM task with objects and letter strings, followed by a surprise LTM test. Slow potentials were found to be more negative over the parietal and occipital cortex for objects and over the left frontal cortex for letter strings during WM maintenance. Within each category, they were enhanced for items that were subsequently successfully remembered. These effects were topographically distinct, with maximum effects at those electrodes that showed the maximum negativity during WM maintenance in general. Together, these results are strongly consistent with the ideas that WM maintenance contributes to LTM formation and that this may occur through strengthening of stimulus-specific cortical memory traces. PMID:17993207

  4. Exploratory study of the relations between spatial ability and drawing from memory.

    PubMed

    Czarnolewski, Mark Y; Eliot, John

    2012-04-01

    Test scores of 119 students, attending either a public four-year college or a technical school, were related to their proportionality and detail drawing scores on the Memory for Designs Test. In regression models, the ETS Maze Tracing, Eliot-Price Mental Rotations, and Bender-Gestalt tests were consistent predictors of proportionality scores, with the latter two tests uniquely related to these. The ETS Shapes Memory Test and the Form Board Test were the strongest predictors for detail accuracy scores. The Shapes test predicted proportionality when the CTY Visual Memory Test BB was excluded. The models then provided support for the hypothesis that drawing designs from memory, a critical skill in drawing, regardless of whether one focuses on accuracy for proportionality scores or for detail scores, is jointly related to the measures of recognition, production, and traditional spatial ability measures. This study identified multifaceted skills in drawing from memory. PMID:22755465

  5. Relations between episodic memory, suggestibility, theory of mind, and cognitive inhibition in the preschool child.

    PubMed

    Melinder, Annika; Endestad, Tor; Magnussen, Svein

    2006-12-01

    The development of episodic memory, its relation to theory of mind (ToM), executive functions (e.g., cognitive inhibition), and to suggestibility was studied. Children (n= 115) between 3 and 6 years of age saw two versions of a video film and were tested for their memory of critical elements of the videos. Results indicated similar developmental trends for all memory measures, ToM, and inhibition, but ToM and inhibition were not associated with any memory measures. Correlations involving source memory was found in relation to specific questions, whereas inhibition and ToM were significantly correlated to resistance to suggestions. A regression analysis showed that age was the main contributor to resistance to suggestions, to correct source monitoring, and to correct responses to specific questions. Inhibition was also a significant main predictor of resistance to suggestive questions, whereas the relative contribution of ToM was wiped out when an extended model was tested. PMID:17107497

  6. Developmental Changes in Memory-Related Linguistic Skills and Their Relationship to Episodic Recall in Children

    PubMed Central

    Uehara, Izumi

    2015-01-01

    This longitudinal study of nine children examined two issues concerning infantile amnesia: the time at which memories for events experienced before the age of 3–4 years disappear from consciousness and whether this timing of memory loss is related to the development of specific aspects of episodic and autobiographical memory. This study followed children from infancy to early childhood and examined the central role of three verbal–cognitive milestones related to autobiographical memory: the age at which children begin to report autobiographical memories using the past tense (Milestone 1); the age at which they begin to verbally acknowledge past events (Milestone 2); and the age at which they begin to spontaneously use memory-related verbs (Milestone 3). As expected, memories of events that occurred before 3–4 years of age were affected by infantile amnesia. Achievement of these milestones followed almost the same developmental progression: Milestone 1 (1 year; 10 months (1;10) to 3 years; 4 months (3;4)) was followed by Milestones 2 (3;1 to 4;0) and 3 (3;5 to 4;4). Milestone 2 was typically related to the onset of infantile amnesia, whereas Milestone 1 occurred during the period for which the children became amnesic as they aged. These data suggest that linguistic meta-cognitive awareness of personal memory is the key feature in infantile amnesia. PMID:26331479

  7. The Relation between Mathematics and Working Memory in Young Children with Fetal Alcohol Spectrum Disorders

    ERIC Educational Resources Information Center

    Rasmussen, Carmen; Bisanz, Jeffrey

    2011-01-01

    The goal of this study was to examine the relation between mathematics and working memory in young children with Fetal Alcohol Spectrum Disorders (FASD). Children with FASD and comparison children (4 to 6 years old) completed standardized tests of mathematics and working memory. Children with FASD showed impairments on mathematics (applied…

  8. Working Memory Effects of Gap-Predictions in Normal Adults: An Event-Related Potentials Study

    ERIC Educational Resources Information Center

    Hestvik, Arild; Bradley, Evan; Bradley, Catherine

    2012-01-01

    The current study examined the relationship between verbal memory span and the latency with which a filler-gap dependency is constructed. A previous behavioral study found that low span listeners did not exhibit antecedent reactivation at gap sites in relative clauses, in comparison to high verbal memory span subjects (Roberts et al. in "J…

  9. Gender Differences in Memory Processing: Evidence from Event-Related Potentials to Faces

    ERIC Educational Resources Information Center

    Guillem, F.; Mograss, M.

    2005-01-01

    This study investigated gender differences on memory processing using event-related potentials (ERPs). Behavioral data and ERPs were recorded in 16 males and 10 females during a recognition memory task for faces. The behavioral data results showed that females performed better than males. Gender differences on ERPs were evidenced over anterior…

  10. Who, When, and Where? Age-Related Differences on a New Memory Test

    ERIC Educational Resources Information Center

    Sumida, Catherine A.; Holden, Heather M.; Van Etten, Emily J.; Wagner, Gabrielle M.; Hileman, Jacob D.; Gilbert, Paul E.

    2016-01-01

    Our study examined age-related differences on a new memory test assessing memory for "who," "when," and "where," and associations among these elements. Participants were required to remember a sequence of pictures of different faces paired with different places. Older adults remembered significantly fewer correct…

  11. Developmental Changes in Memory Encoding: Insights from Event-Related Potentials

    ERIC Educational Resources Information Center

    Rollins, Leslie; Riggins, Tracy

    2013-01-01

    The aim of the present study was to investigate developmental changes in encoding processes between 6-year-old children and adults using event-related potentials (ERPs). Although episodic memory ("EM") effects have been reported in both children and adults at retrieval and subsequent memory effects have been established in adults, no…

  12. Time-Related Decay or Interference-Based Forgetting in Working Memory?

    ERIC Educational Resources Information Center

    Portrat, Sophie; Barrouillet, Pierre; Camos, Valerie

    2008-01-01

    The time-based resource-sharing model of working memory assumes that memory traces suffer from a time-related decay when attention is occupied by concurrent activities. Using complex continuous span tasks in which temporal parameters are carefully controlled, P. Barrouillet, S. Bernardin, S. Portrat, E. Vergauwe, & V. Camos (2007) recently…

  13. Working Memory Effects in the L2 Processing of Ambiguous Relative Clauses

    ERIC Educational Resources Information Center

    Hopp, Holger

    2014-01-01

    This article investigates whether and how L2 sentence processing is affected by memory constraints that force serial parsing. Monitoring eye movements, we test effects of working memory on L2 relative-clause attachment preferences in a sample of 75 late-adult German learners of English and 25 native English controls. Mixed linear regression…

  14. Relation between Intelligence and Short-Term Memory

    ERIC Educational Resources Information Center

    Cohen, Ronald L.; Sandberg, Tor

    1977-01-01

    Intelligence and short-term memory correlations in children were measured using probed serial recall of supraspan digit lists. Results showed the predictive power of intelligence to range from a maximum in the case of recall for recency items to practically zero in the case of primacy items. (Author/MV)

  15. Working Memory Compensates for Hearing Related Phonological Processing Deficit

    ERIC Educational Resources Information Center

    Classon, Elisabet; Rudner, Mary; Ronnberg, Jerker

    2013-01-01

    Acquired hearing impairment is associated with gradually declining phonological representations. According to the Ease of Language Understanding (ELU) model, poorly defined representations lead to mismatch in phonologically challenging tasks. To resolve the mismatch, reliance on working memory capacity (WMC) increases. This study investigated…

  16. Age-related Changes in the Sleep-dependent Reorganization of Declarative Memories.

    PubMed

    Baran, Bengi; Mantua, Janna; Spencer, Rebecca M C

    2016-06-01

    Consolidation of declarative memories has been associated with slow wave sleep in young adults. Previous work suggests that, in spite of changes in sleep, sleep-dependent consolidation of declarative memories may be preserved with aging, although reduced relative to young adults. Previous work on young adults shows that, with consolidation, retrieval of declarative memories gradually becomes independent of the hippocampus. To investigate whether memories are similarly reorganized over sleep at the neural level, we compared functional brain activation associated with word pair recall following a nap and equivalent wake in young and older adults. SWS during the nap predicted better subsequent memory recall and was negatively associated with retrieval-related hippocampal activation in young adults. In contrast, in older adults there was no relationship between sleep and memory performance or with retrieval-related hippocampal activation. Furthermore, compared with young adults, postnap memory retrieval in older adults required strong functional connectivity of the hippocampus with the PFC, whereas there were no differences between young and older adults in the functional connectivity of the hippocampus following wakefulness. These results suggest that, although neural reorganization takes place over sleep in older adults, the shift is unique from that seen in young adults, perhaps reflecting memories at an earlier stage of stabilization. PMID:26918588

  17. Age-related decline of precision and binding in visual working memory.

    PubMed

    Peich, Muy-Cheng; Husain, Masud; Bays, Paul M

    2013-09-01

    Working memory declines with normal aging, but the nature of this impairment is debated. Studies based on detecting changes to arrays of visual objects have identified two possible components to age-related decline: a reduction in the number of items that can be stored, or a deficit in maintaining the associations (bindings) between individual object features. However, some investigations have reported intact binding with aging, and specific deficits arising only in Alzheimer's disease. Here, using a recently developed continuous measure of recall fidelity, we tested the precision with which adults of different ages could reproduce from memory the orientation and color of a probed array item. The results reveal a further component of cognitive decline: an age-related decrease in the resolution with which visual information can be maintained in working memory. This increase in recall variability with age was strongest under conditions of greater memory load. Moreover, analysis of the distribution of errors revealed that older participants were more likely to incorrectly report one of the unprobed items in memory, consistent with an age-related increase in misbinding. These results indicate a systematic decline with age in working memory resources that can be recruited to store visual information. The paradigm presented here provides a sensitive index of both memory resolution and feature binding, with the potential for assessing their modulation by interventions. The findings have implications for understanding the mechanisms underpinning working memory deficits in both health and disease. PMID:23978008

  18. Band bending effect induced by gate voltage on the charge loss behavior of charge trap flash memory devices

    NASA Astrophysics Data System (ADS)

    Chang, M.; Hwang, H.; Jeon, S.

    2010-02-01

    We found that the polarity of the gate voltage (Vg) during the retention characteristics for a SiO2/Si3N4/Al2O3 (ONA) stack can affect the charge loss direction, due to band bending. Positive Vg could induce electron de-trapping through Al2O3, while a negative Vg could induce the same through SiO2. Consequently, the charge loss rates exhibited a hairpin curve with Vg. We clearly observed that increases of the SiO2 thickness of the ONA stack induced negative shifts of hairpin curve. This result suggests that the dominant charge loss path could be changed from SiO2 to Al2O3 by increasing the SiO2 thickness without Vg.

  19. Familiarity is related to conceptual implicit memory: an examination of individual differences.

    PubMed

    Wang, Wei-chun; Yonelinas, Andrew P

    2012-12-01

    Explicit memory is thought to be distinct from implicit memory. However, growing evidence has indicated that explicit familiarity-based recognition memory judgments rely on the same process that supports conceptual implicit memory. We tested this hypothesis by examining individual differences using a paradigm wherein we measured both familiarity and conceptual implicit memory within the same participants. In Experiments 1a and 1b, we examined recognition memory confidence ROCs and remember/know responses, respectively, to estimate recollection and familiarity, and used a free association task to measure conceptual implicit memory. The results demonstrated that, across participants, familiarity, but not recollection, was significantly correlated with conceptual priming. In contrast, in Experiment 2, utilizing a similar paradigm, a comparison of recognition memory ROCs and explicit associative cued-recall performance indicated that cued recall was related to both recollection and familiarity. These results are consistent with models assuming that familiarity-based recognition and conceptual implicit memory rely on similar underlying processes. PMID:22833341

  20. Low working memory capacity is only spuriously related to poor reading comprehension.

    PubMed

    Van Dyke, Julie A; Johns, Clinton L; Kukona, Anuenue

    2014-06-01

    Accounts of comprehension failure, whether in the case of readers with poor skill or when syntactic complexity is high, have overwhelmingly implicated working memory capacity as the key causal factor. However, extant research suggests that this position is not well supported by evidence on the span of active memory during online sentence processing, nor is it well motivated by models that make explicit claims about the memory mechanisms that support language processing. The current study suggests that sensitivity to interference from similar items in memory may provide a better explanation of comprehension failure. Through administration of a comprehensive skill battery, we found that the previously observed association of working memory with comprehension is likely due to the collinearity of working memory with many other reading-related skills, especially IQ. In analyses which removed variance shared with IQ, we found that receptive vocabulary knowledge was the only significant predictor of comprehension performance in our task out of a battery of 24 skill measures. In addition, receptive vocabulary and non-verbal memory for serial order-but not simple verbal memory or working memory-were the only predictors of reading times in the region where interference had its primary affect. We interpret these results in light of a model that emphasizes retrieval interference and the quality of lexical representations as key determinants of successful comprehension. PMID:24657820

  1. The relation between navigation strategy and associative memory: An individual differences approach.

    PubMed

    Ngo, Chi T; Weisberg, Steven M; Newcombe, Nora S; Olson, Ingrid R

    2016-04-01

    Although the hippocampus is implicated in both spatial navigation and associative memory, very little is known about whether individual differences in the 2 domains covary. People who prefer to navigate using a hippocampal-dependent place strategy may show better performance on associative memory tasks than those who prefer a caudate-dependent response strategy (Bohbot, Gupta, Banner, & Dahmani, 2011), but not all studies suggest such an effect (Woollett & Maguire, 2009, 2012). Here we tested nonexpert young adults and found that preference for a place strategy positively correlated with spatial (object-location) associative memory performance but did not correlate with nonspatial (face-name) associative memory performance. Importantly, these correlations differed from each other, indicating that the relation between navigation strategy and associative memory is specific to the spatial domain. In addition, the 2 associative memory tasks significantly correlated, suggesting that object-location memory taps into processes relevant to both hippocampal-dependent navigation and nonspatial associative memory. Our findings also suggest that individual differences in spatial associative memory may account for some of the variance in navigation strategies. (PsycINFO Database Record PMID:26501930

  2. Computer memory access technique

    NASA Technical Reports Server (NTRS)

    Zottarelli, L. J.

    1967-01-01

    Computer memory access commutator and steering gate configuration produces bipolar current pulses while still employing only the diodes and magnetic cores of the classic commutator, thereby appreciably reducing the complexity of the memory assembly.

  3. Insightful Imagery is Related to Working Memory Updating

    PubMed Central

    Nęcka, Edward; Żak, Piotr; Gruszka, Aleksandra

    2016-01-01

    Available body of evidence concerning the relationship between insight problem solving and working memory (WM) is ambiguous. Several authors propose that restructuring of the problem representation requires controlled search processes, which needs planning and involvement of WM. Other researchers suggest that the restructuring is achieved through the automatic spread of activation in long-term memory, assigning a limited role to WM capacity. In the present study we examined the correlations between insight problem solving performance and measures of WM updating function (n-back task), including general intelligence (as measured by Raven’s Advanced Progressive Matrices). The results revealed that updating function shared up to 30% of variance with the insight problem task performance, even when the influence of general mental ability was controlled for. These results suggest that insight problem solving is constrained by individual ability to update the content of WM. PMID:26973549

  4. Insightful Imagery is Related to Working Memory Updating.

    PubMed

    Nęcka, Edward; Żak, Piotr; Gruszka, Aleksandra

    2016-01-01

    Available body of evidence concerning the relationship between insight problem solving and working memory (WM) is ambiguous. Several authors propose that restructuring of the problem representation requires controlled search processes, which needs planning and involvement of WM. Other researchers suggest that the restructuring is achieved through the automatic spread of activation in long-term memory, assigning a limited role to WM capacity. In the present study we examined the correlations between insight problem solving performance and measures of WM updating function (n-back task), including general intelligence (as measured by Raven's Advanced Progressive Matrices). The results revealed that updating function shared up to 30% of variance with the insight problem task performance, even when the influence of general mental ability was controlled for. These results suggest that insight problem solving is constrained by individual ability to update the content of WM. PMID:26973549

  5. Motivated encoding selectively promotes memory for future inconsequential semantically-related events.

    PubMed

    Oyarzún, Javiera P; Packard, Pau A; de Diego-Balaguer, Ruth; Fuentemilla, Lluis

    2016-09-01

    Neurobiological models of long-term memory explain how memory for inconsequential events fades, unless these happen before or after other relevant (i.e., rewarding or aversive) or novel events. Recently, it has been shown in humans that retrospective and prospective memories are selectively enhanced if semantically related events are paired with aversive stimuli. However, it remains unclear whether motivating stimuli, as opposed to aversive, have the same effect in humans. Here, participants performed a three phase incidental encoding task where one semantic category was rewarded during the second phase. A memory test 24h after, but not immediately after encoding, revealed that memory for inconsequential items was selectively enhanced only if items from the same category had been previously, but not subsequently, paired with rewards. This result suggests that prospective memory enhancement of reward-related information requires, like previously reported for aversive memories, of a period of memory consolidation. The current findings provide the first empirical evidence in humans that the effects of motivated encoding are selectively and prospectively prolonged over time. PMID:27224885

  6. Retrograde amnesia: a study of its relation to anterograde amnesia and semantic memory deficits.

    PubMed

    Schmidtke, K; Vollmer, H

    1997-04-01

    This group study of 24 amnesic patients and 40 control subjects examined the hypothesis that retrograde memory deficits result from a combination of two impairment mechanisms: (1) a deficit in the retrieval of contents that is related to dysfunctioning of the hippocampal anterograde memory system, and (2) a deficit in the storage and/or retrieval of contents that is related to concomitant neocortical lesions. Retrograde amnesia was evaluated with the use of new Famous Persons and Autobiographical Memory Tests. The postulated components of retrograde memory impairment were assessed using the Wechsler Memory Scale and a new Semantic Memory Test, respectively. Regression analyses showed that recent episodic autobiography was exclusively related to the hippocampal component, while memory for famous persons and childhood autobiography was related to the neocortical component. In the case of details concerning people of recent fame, both components were identified as independent determinants. The temporal gradient of patients' impairment at the Famous Persons Test was marked for detailed knowledge, but small for overlearned knowledge. The present results thus support the combination hypothesis. They conform to the view that the transition from a hippocampus-dependent to a neocortex-dependent mnemonic representation of new contents is mediated by reiteration, and occurs within 5-10 years. PMID:9106279

  7. Memories.

    ERIC Educational Resources Information Center

    Brand, Judith, Ed.

    1998-01-01

    This theme issue of the journal "Exploring" covers the topic of "memories" and describes an exhibition at San Francisco's Exploratorium that ran from May 22, 1998 through January 1999 and that contained over 40 hands-on exhibits, demonstrations, artworks, images, sounds, smells, and tastes that demonstrated and depicted the biological,…

  8. Effects of memory strategy training on performance and event-related brain potentials of children with ADHD in an episodic memory task.

    PubMed

    Jonkman, Lisa M; Hurks, Petra P; Schleepen, Tamara M J

    2016-10-01

    Evidence for memory problems in children with attention deficit hyperactivity disorder (ADHD) is accumulating. Attempting to counter such problems, in the present study children with ADHD aged 8-12 years underwent a six-week metacognitive memory strategy training (MST) or one of two other active trainings, either a metacognitive attention-perceptual-motor training (APM) or placebo training consisting of playing board games (PLA). Effects of the training on episodic memory and underlying brain processes were investigated by comparing performance and event-related brain potentials (ERPs) on pre- and post-training sessions in an old/new recognition task between the three training groups. Potential far transfer effects of the memory strategy training were investigated by measuring performance on neuropsychological attention and memory-span tasks and parent-rated ADHD symptoms. The metacognitive memory strategy training led to significantly improved memory performance and enhanced amplitude of left parietal P600 activity associated with the process of memory recollection when compared to PLA, but APM training evoked similar improvements. Memory performance gains were significantly correlated with the memory-related ERP effects. Preliminary far transfer effects of MST training were found on attention and working memory performance and on parent-rated ADHD symptoms, although these results need replication with larger and better IQ-matched groups. PMID:26251965

  9. Increased attention and memory for beloved-related information during infatuation: behavioral and electrophysiological data

    PubMed Central

    Olivier, Jamie R.; Köhlen, Martine E.; Nijs, Ilse M.; Van Strien, Jan W.

    2015-01-01

    Emotionally salient information is well attended and remembered. It has been shown that infatuated individuals have increased attention for their beloved. It is unknown whether this attention bias generalizes to information related to the beloved. Moreover, infatuated individuals report to remember trivial things about their beloved, but this has not yet been tested empirically. In two studies, we tested whether infatuated individuals have increased attention and memory for beloved-related information. In a passive viewing task (Study 1), the late positive potential, an event-related potential (ERP) component reflecting motivated attention, was enhanced for beloved-related vs friend-related words/phrases. In a recognition task (Study 2), memory performance and the frontal and parietal ERP old/new effects, reflecting familiarity and recollection, respectively, were not enhanced for beloved-related compared with friend-related words/phrases. In free recall tasks in both studies, memory was better for beloved-related than friend-related words/phrases. This research reveals that attention and memory are enhanced for beloved-related information. These attention and memory biases for beloved-related information were not due to valence, semantic relatedness, or experience, but to arousal. To conclude, romantic love has profound effects on cognition that play a clear role in daily life. PMID:24526182

  10. Increased attention and memory for beloved-related information during infatuation: behavioral and electrophysiological data.

    PubMed

    Langeslag, Sandra J E; Olivier, Jamie R; Köhlen, Martine E; Nijs, Ilse M; Van Strien, Jan W

    2015-01-01

    Emotionally salient information is well attended and remembered. It has been shown that infatuated individuals have increased attention for their beloved. It is unknown whether this attention bias generalizes to information related to the beloved. Moreover, infatuated individuals report to remember trivial things about their beloved, but this has not yet been tested empirically. In two studies, we tested whether infatuated individuals have increased attention and memory for beloved-related information. In a passive viewing task (Study 1), the late positive potential, an event-related potential (ERP) component reflecting motivated attention, was enhanced for beloved-related vs friend-related words/phrases. In a recognition task (Study 2), memory performance and the frontal and parietal ERP old/new effects, reflecting familiarity and recollection, respectively, were not enhanced for beloved-related compared with friend-related words/phrases. In free recall tasks in both studies, memory was better for beloved-related than friend-related words/phrases. This research reveals that attention and memory are enhanced for beloved-related information. These attention and memory biases for beloved-related information were not due to valence, semantic relatedness, or experience, but to arousal. To conclude, romantic love has profound effects on cognition that play a clear role in daily life. PMID:24526182

  11. Executive function deficits in early Alzheimer's disease and their relations with episodic memory.

    PubMed

    Baudic, Sophie; Barba, Gianfranco Dalla; Thibaudet, Marie Claude; Smagghe, Alain; Remy, Philippe; Traykov, Latchezar

    2006-01-01

    Previous research suggests that patients with Alzheimer's disease (AD) are impaired on executive function early in the course of disease, but negative findings were reported. To evaluate the performance on executive tasks in early AD and to determine the involvement of memory on the outcome of executive tasks. Thirty-six AD patients were divided into two subgroups on the basis of the MMSE: very mild and mild. The comparison with 17 normal controls shows that very mild AD patients had deficits on visuospatial short-term memory, episodic memory, flexibility and self-monitoring abilities, concept formation and reasoning. The mild AD patients showed additional deficits on the Similarities test. Episodic memory and executive deficits occur in the very early stage of AD and precede impairment in constructional praxis, language and sustained attention. With the progression of the disease, additional deficit is observed in abstract thinking. In mild AD, memory failure is also related to executive impairment. PMID:16125364

  12. Individual differences in algebraic cognition: Relation to the approximate number and semantic memory systems.

    PubMed

    Geary, David C; Hoard, Mary K; Nugent, Lara; Rouder, Jeffrey N

    2015-12-01

    The relation between performance on measures of algebraic cognition and acuity of the approximate number system (ANS) and memory for addition facts was assessed for 171 ninth graders (92 girls) while controlling for parental education, sex, reading achievement, speed of numeral processing, fluency of symbolic number processing, intelligence, and the central executive component of working memory. The algebraic tasks assessed accuracy in placing x,y pairs in the coordinate plane, speed and accuracy of expression evaluation, and schema memory for algebra equations. ANS acuity was related to accuracy of placements in the coordinate plane and expression evaluation but not to schema memory. Frequency of fact retrieval errors was related to schema memory but not to coordinate plane or expression evaluation accuracy. The results suggest that the ANS may contribute to or be influenced by spatial-numerical and numerical-only quantity judgments in algebraic contexts, whereas difficulties in committing addition facts to long-term memory may presage slow formation of memories for the basic structure of algebra equations. More generally, the results suggest that different brain and cognitive systems are engaged during the learning of different components of algebraic competence while controlling for demographic and domain general abilities. PMID:26255604

  13. Lead-Induced Impairments in the Neural Processes Related to Working Memory Function

    PubMed Central

    Jin, Seong-Uk; Park, Jang Woo; Kim, Yang-Tae; Ryeom, Hun-Kyu; Lee, Jongmin; Suh, Kyung Jin; Kim, Suk Hwan; Park, Sin-Jae; Jeong, Kyoung Sook; Ham, Jung-O; Kim, Yangho; Chang, Yongmin

    2014-01-01

    Background It is well known that lead exposure induces neurotoxic effects, which can result in a variety of neurocognitive dysfunction. Especially, occupational lead exposures in adults are associated with decreases in cognitive performance including working memory. Despite recent advances in human neuroimaging techniques, the neural correlates of lead-exposed cognitive impairment remain unclear. Therefore, this study was aimed to compare the neural activations in relation to working memory function between the lead-exposed subjects and healthy controls. Methodology/Principal Findings Thirty-one lead-exposed subjects and 34 healthy subjects performed an n-back memory task during MRI scan. We performed fMRI using the 1-back and 2-back memory tasks differing in cognitive demand. Functional MRI data were analyzed using within- and between-group analysis. We found that the lead-exposed subjects showed poorer working memory performance during high memory loading task than the healthy subjects. In addition, between-group analyses revealed that the lead-exposed subjects showed reduced activation in the dorsolateral prefrontal cortex, ventrolateral prefrontal cortex, pre supplementary motor areas, and inferior parietal cortex. Conclusions/Significance Our findings suggest that functional abnormalities in the frontoparietal working memory network might contribute to impairments in maintenance and manipulation of working memory in the lead-exposed subjects. PMID:25141213

  14. Low working memory capacity is only spuriously related to poor reading comprehension

    PubMed Central

    Van Dyke, Julie A.; Johns, Clinton L.; Kukona, Anuenue

    2014-01-01

    Accounts of comprehension failure, whether in the case of readers with poor skill or when syntactic complexity is high, have overwhelmingly implicated working memory capacity as the key causal factor. However, extant research suggests that this position is not well supported by evidence on the span of active memory during online sentence processing, nor is it well motivated by models that make explicit claims about the memory mechanisms that support language processing. The current study suggests that sensitivity to interference from similar items in memory may provide a better explanation of comprehension failure. Through administration of a comprehensive skill battery, we found that the previously observed association of working memory with comprehension is likely due to the collinearity of working memory with many other reading-related skills, especially IQ. In analyses which removed variance shared with IQ, we found that receptive vocabulary knowledge was the only significant predictor of comprehension performance in our task out of a battery of 24 skill measures. In addition, receptive vocabulary and non-verbal memory for serial order—but not simple verbal memory or working memory—were the only predictors of reading times in the region where interference had its primary affect. We interpret these results in light of a model that emphasizes retrieval interference and the quality of lexical representations as key determinants of successful comprehension. PMID:24657820

  15. Phase of Spontaneous Slow Oscillations during Sleep Influences Memory-Related Processing of Auditory Cues

    PubMed Central

    Creery, Jessica D.; Paller, Ken A.

    2016-01-01

    Slow oscillations during slow-wave sleep (SWS) may facilitate memory consolidation by regulating interactions between hippocampal and cortical networks. Slow oscillations appear as high-amplitude, synchronized EEG activity, corresponding to upstates of neuronal depolarization and downstates of hyperpolarization. Memory reactivations occur spontaneously during SWS, and can also be induced by presenting learning-related cues associated with a prior learning episode during sleep. This technique, targeted memory reactivation (TMR), selectively enhances memory consolidation. Given that memory reactivation is thought to occur preferentially during the slow-oscillation upstate, we hypothesized that TMR stimulation effects would depend on the phase of the slow oscillation. Participants learned arbitrary spatial locations for objects that were each paired with a characteristic sound (eg, cat–meow). Then, during SWS periods of an afternoon nap, one-half of the sounds were presented at low intensity. When object location memory was subsequently tested, recall accuracy was significantly better for those objects cued during sleep. We report here for the first time that this memory benefit was predicted by slow-wave phase at the time of stimulation. For cued objects, location memories were categorized according to amount of forgetting from pre- to post-nap. Conditions of high versus low forgetting corresponded to stimulation timing at different slow-oscillation phases, suggesting that learning-related stimuli were more likely to be processed and trigger memory reactivation when they occurred at the optimal phase of a slow oscillation. These findings provide insight into mechanisms of memory reactivation during sleep, supporting the idea that reactivation is most likely during cortical upstates. SIGNIFICANCE STATEMENT Slow-wave sleep (SWS) is characterized by synchronized neural activity alternating between active upstates and quiet downstates. The slow-oscillation upstates are

  16. Working memory performance inversely predicts spontaneous delta and theta-band scaling relations.

    PubMed

    Euler, Matthew J; Wiltshire, Travis J; Niermeyer, Madison A; Butner, Jonathan E

    2016-04-15

    Electrophysiological studies have strongly implicated theta-band activity in human working memory processes. Concurrently, work on spontaneous, non-task-related oscillations has revealed the presence of long-range temporal correlations (LRTCs) within sub-bands of the ongoing EEG, and has begun to demonstrate their functional significance. However, few studies have yet assessed the relation of LRTCs (also called scaling relations) to individual differences in cognitive abilities. The present study addressed the intersection of these two literatures by investigating the relation of narrow-band EEG scaling relations to individual differences in working memory ability, with a particular focus on the theta band. Fifty-four healthy adults completed standardized assessments of working memory and separate recordings of their spontaneous, non-task-related EEG. Scaling relations were quantified in each of the five classical EEG frequency bands via the estimation of the Hurst exponent obtained from detrended fluctuation analysis. A multilevel modeling framework was used to characterize the relation of working memory performance to scaling relations as a function of general scalp location in Cartesian space. Overall, results indicated an inverse relationship between both delta and theta scaling relations and working memory ability, which was most prominent at posterior sensors, and was independent of either spatial or individual variability in band-specific power. These findings add to the growing literature demonstrating the relevance of neural LRTCs for understanding brain functioning, and support a construct- and state-dependent view of their functional implications. PMID:26872594

  17. Mitigation of cache memory using an embedded hard-core PPC440 processor in a Virtex-5 Field Programmable Gate Array.

    SciTech Connect

    Learn, Mark Walter

    2010-02-01

    Sandia National Laboratories is currently developing new processing and data communication architectures for use in future satellite payloads. These architectures will leverage the flexibility and performance of state-of-the-art static-random-access-memory-based Field Programmable Gate Arrays (FPGAs). One such FPGA is the radiation-hardened version of the Virtex-5 being developed by Xilinx. However, not all features of this FPGA are being radiation-hardened by design and could still be susceptible to on-orbit upsets. One such feature is the embedded hard-core PPC440 processor. Since this processor is implemented in the FPGA as a hard-core, traditional mitigation approaches such as Triple Modular Redundancy (TMR) are not available to improve the processor's on-orbit reliability. The goal of this work is to investigate techniques that can help mitigate the embedded hard-core PPC440 processor within the Virtex-5 FPGA other than TMR. Implementing various mitigation schemes reliably within the PPC440 offers a powerful reconfigurable computing resource to these node-based processing architectures. This document summarizes the work done on the cache mitigation scheme for the embedded hard-core PPC440 processor within the Virtex-5 FPGAs, and describes in detail the design of the cache mitigation scheme and the testing conducted at the radiation effects facility on the Texas A&M campus.

  18. The relation between working memory components and ADHD symptoms from a developmental perspective.

    PubMed

    Tillman, Carin; Eninger, Lilianne; Forssman, Linda; Bohlin, Gunilla

    2011-01-01

    The objective was to examine the relations between attention deficit hyperactivity disorder (ADHD) symptoms and four working memory (WM) components (short-term memory and central executive in verbal and visuospatial domains) in 284 6-16-year-old children from the general population. The results showed that verbal and visuospatial short-term memory and verbal central executive uniquely contributed to inattention symptoms. Age interacted with verbal short-term memory in predicting inattention, with the relation being stronger in older children. These findings support the notion of ADHD as a developmental disorder, with changes in associated neuropsychological deficits across time. The results further indicate ADHD-related deficits in several specific WM components. PMID:21347920

  19. The influence of object relative size on priming and explicit memory.

    PubMed

    Uttl, Bob; Graf, Peter; Siegenthaler, Amy L

    2008-01-01

    We investigated the effects of object relative size on priming and explicit memory for color photos of common objects. Participants were presented with color photos of pairs of objects displayed in either appropriate or inappropriate relative sizes. Implicit memory was assessed by speed of object size ratings whereas explicit memory was assessed by an old/new recognition test. Study-to-test changes in relative size reduced both priming and explicit memory and had large effects for objects displayed in large vs. small size at test. Our findings of substantial size-specific influences on priming with common objects under some but not other conditions are consistent with instance views of object perception and priming but inconsistent with structural description views. PMID:18769670

  20. Early age-related changes in episodic memory retrieval as revealed by event-related potentials.

    PubMed

    Guillaume, Cécile; Clochon, Patrice; Denise, Pierre; Rauchs, Géraldine; Guillery-Girard, Bérengère; Eustache, Francis; Desgranges, Béatrice

    2009-01-28

    Familiarity is better preserved than recollection in ageing. The age at which changes first occur and the slope of the subsequent decline, however, remain unclear. In this study, we investigated changes in episodic memory, by using event-related potentials (ERPs) in young (m=24), middle-aged (m=58) and older (m=70) adults. Although behavioural performance did not change before the age of 65 years, changes in ERP correlates were already present in the middle-aged adults. The ERP correlates of recollection and monitoring processes were the first to be affected by ageing, with a linear decrease as age increased. Conversely, the ERP correlate of familiarity remained unchanged, at least up to the age of 65 years. These results suggest a differential time course for the age effects on episodic retrieval. PMID:19104457

  1. [Current understanding of sleep, dreaming and related memory consolidation].

    PubMed

    Han, Victor Z; Shi, Jun-Han

    2013-12-01

    Sleep is a naturally recurring state found throughout the animal kingdom and characterized by a reversible loss of consciousness. Although in humans the daily amount of sleep decreases with aging, the total amount of time spent for sleep is estimated as up to one-third of one's lifetime. In mammals, sleep shows a clear daily rhythmicity as well as nightly phases, which are strongly controlled by the circadian clock located in the hypothalamic suprachiasmatic nuclei and are also regulated by ambient light. While it is certain that sleep is critical for survival in general, the functional significance of sleep is still under investigation. Dreaming is a common psychological phenomenon occurring during human sleep, yet its content and natural function, if any, are still a matter of debate. In recent years, accumulated evidence strongly supports the notion that new information acquired during the day time is processed and transformed into long-term memory in a complicated and sophisticated way during sleeping. Such information processing is commonly referred to as memory consolidation. PMID:24665738

  2. The Associative Memory Deficit in Aging Is Related to Reduced Selectivity of Brain Activity during Encoding.

    PubMed

    Saverino, Cristina; Fatima, Zainab; Sarraf, Saman; Oder, Anita; Strother, Stephen C; Grady, Cheryl L

    2016-09-01

    Human aging is characterized by reductions in the ability to remember associations between items, despite intact memory for single items. Older adults also show less selectivity in task-related brain activity, such that patterns of activation become less distinct across multiple experimental tasks. This reduced selectivity or dedifferentiation has been found for episodic memory, which is often reduced in older adults, but not for semantic memory, which is maintained with age. We used fMRI to investigate whether there is a specific reduction in selectivity of brain activity during associative encoding in older adults, but not during item encoding, and whether this reduction predicts associative memory performance. Healthy young and older adults were scanned while performing an incidental encoding task for pictures of objects and houses under item or associative instructions. An old/new recognition test was administered outside the scanner. We used agnostic canonical variates analysis and split-half resampling to detect whole-brain patterns of activation that predicted item versus associative encoding for stimuli that were later correctly recognized. Older adults had poorer memory for associations than did younger adults, whereas item memory was comparable across groups. Associative encoding trials, but not item encoding trials, were predicted less successfully in older compared with young adults, indicating less distinct patterns of associative-related activity in the older group. Importantly, higher probability of predicting associative encoding trials was related to better associative memory after accounting for age and performance on a battery of neuropsychological tests. These results provide evidence that neural distinctiveness at encoding supports associative memory and that a specific reduction of selectivity in neural recruitment underlies age differences in associative memory. PMID:27082043

  3. Electrically programmable-erasable In-Ga-Zn-O thin-film transistor memory with atomic-layer-deposited Al2O3/Pt nanocrystals/Al2O3 gate stack

    NASA Astrophysics Data System (ADS)

    Qian, Shi-Bing; Zhang, Wen-Peng; Liu, Wen-Jun; Ding, Shi-Jin

    2015-12-01

    Amorphous indium-gallium-zinc oxide (a-IGZO) thin-film transistor (TFT) memory is very promising for transparent and flexible system-on-panel displays; however, electrical erasability has always been a severe challenge for this memory. In this article, we demonstrated successfully an electrically programmable-erasable memory with atomic-layer-deposited Al2O3/Pt nanocrystals/Al2O3 gate stack under a maximal processing temperature of 300 oC. As the programming voltage was enhanced from 14 to 19 V for a constant pulse of 0.2 ms, the threshold voltage shift increased significantly from 0.89 to 4.67 V. When the programmed device was subjected to an appropriate pulse under negative gate bias, it could return to the original state with a superior erasing efficiency. The above phenomena could be attributed to Fowler-Nordheim tunnelling of electrons from the IGZO channel to the Pt nanocrystals during programming, and inverse tunnelling of the trapped electrons during erasing. In terms of 0.2-ms programming at 16 V and 350-ms erasing at -17 V, a large memory window of 3.03 V was achieved successfully. Furthermore, the memory exhibited stable repeated programming/erasing (P/E) characteristics and good data retention, i.e., for 2-ms programming at 14 V and 250-ms erasing at -14 V, a memory window of 2.08 V was still maintained after 103 P/E cycles, and a memory window of 1.1 V was retained after 105 s retention time.

  4. Electrically programmable-erasable In-Ga-Zn-O thin-film transistor memory with atomic-layer-deposited Al{sub 2}O{sub 3}/Pt nanocrystals/Al{sub 2}O{sub 3} gate stack

    SciTech Connect

    Qian, Shi-Bing; Zhang, Wen-Peng; Liu, Wen-Jun; Ding, Shi-Jin

    2015-12-15

    Amorphous indium-gallium-zinc oxide (a-IGZO) thin-film transistor (TFT) memory is very promising for transparent and flexible system-on-panel displays; however, electrical erasability has always been a severe challenge for this memory. In this article, we demonstrated successfully an electrically programmable-erasable memory with atomic-layer-deposited Al{sub 2}O{sub 3}/Pt nanocrystals/Al{sub 2}O{sub 3} gate stack under a maximal processing temperature of 300 {sup o}C. As the programming voltage was enhanced from 14 to 19 V for a constant pulse of 0.2 ms, the threshold voltage shift increased significantly from 0.89 to 4.67 V. When the programmed device was subjected to an appropriate pulse under negative gate bias, it could return to the original state with a superior erasing efficiency. The above phenomena could be attributed to Fowler-Nordheim tunnelling of electrons from the IGZO channel to the Pt nanocrystals during programming, and inverse tunnelling of the trapped electrons during erasing. In terms of 0.2-ms programming at 16 V and 350-ms erasing at −17 V, a large memory window of 3.03 V was achieved successfully. Furthermore, the memory exhibited stable repeated programming/erasing (P/E) characteristics and good data retention, i.e., for 2-ms programming at 14 V and 250-ms erasing at −14 V, a memory window of 2.08 V was still maintained after 10{sup 3} P/E cycles, and a memory window of 1.1 V was retained after 10{sup 5} s retention time.

  5. Tracking the intrusion of unwanted memories into awareness with event-related potentials.

    PubMed

    Hellerstedt, Robin; Johansson, Mikael; Anderson, Michael C

    2016-08-01

    Involuntary retrieval of unwanted memories is a common symptom in several clinical disorders, including post-traumatic stress disorder. With an aim to track the temporal dynamics of such memory intrusions, we recorded electrophysiological measures of brain activity while participants engaged in a Think/No-Think task. We presented the left hand word (the cue) of previously encoded word pairs in green or red font. We asked participants to think of the associated right hand word (the associate) when the cue appeared in green (Think condition) and to avoid thinking of the associate when the cue appeared in red (No-Think condition). To isolate cases when participants experienced an intrusive memory, at the end of each trial, participants judged whether the response had come to mind; we classified memories that came to mind during No-Think trials, despite efforts to stop retrieval, as intrusions. In an event-related potential (ERP) analysis, we observed a negative going slow wave (NSW) effect that indexed the duration of a trace in mnemonic awareness; whereas voluntary retrieval and maintenance of the associate was related to a sustained NSW that lasted throughout the 3-s recording epoch, memory intrusions generated short-lived NSWs that were rapidly truncated. Based on these findings, we hypothesize that the intrusion-NSW reflects the associate briefly penetrating working memory. More broadly, these findings exploit the high temporal resolution of ERPs to track the online dynamics of memory intrusions. PMID:27396675

  6. Insulin-like growth factor 2 rescues aging-related memory loss in rats.

    PubMed

    Steinmetz, Adam B; Johnson, Sarah A; Iannitelli, Dylan E; Pollonini, Gabriella; Alberini, Cristina M

    2016-08-01

    Aging is accompanied by declines in memory performance, and particularly affects memories that rely on hippocampal-cortical systems, such as episodic and explicit. With aged populations significantly increasing, the need for preventing or rescuing memory deficits is pressing. However, effective treatments are lacking. Here, we show that the level of the mature form of insulin-like growth factor 2 (IGF-2), a peptide regulated in the hippocampus by learning, required for memory consolidation and a promoter of memory enhancement in young adult rodents, is significantly reduced in hippocampal synapses of aged rats. By contrast, the hippocampal level of the immature form proIGF-2 is increased, suggesting an aging-related deficit in IGF-2 processing. In agreement, aged compared to young adult rats are deficient in the activity of proprotein convertase 2, an enzyme that likely mediates IGF-2 posttranslational processing. Hippocampal administration of the recombinant, mature form of IGF-2 rescues hippocampal-dependent memory deficits and working memory impairment in aged rats. Thus, IGF-2 may represent a novel therapeutic avenue for preventing or reversing aging-related cognitive impairments. PMID:27318130

  7. Spatial working memory deficits in schizophrenia patients and their first degree relatives from Palau, Micronesia.

    PubMed

    Myles-Worsley, Marina; Park, Sohee

    2002-08-01

    Spatial working memory deficits associated with dorsolateral prefrontal dysfunction have been found in Caucasian samples of schizophrenia patients and their first-degree relatives. This study evaluated spatial working memory function in affected and unaffected members of multiplex schizophrenia families from the Republic of Palau to determine whether the spatial working memory deficits associated with schizophrenia extend to this non-Caucasian population. Palau is an isolated island nation in Micronesia with an elevated prevalence of schizophrenia and an aggregation of cases in large multigenerational families. Our objective was to evaluate the potential for spatial working memory function to serve as one of multiple endophenotypes in a genetic linkage study of these Palauan schizophrenia families. A spatial delayed response task requiring resistance to distraction and a sensorimotor control task were used to assess spatial working memory in 32 schizophrenia patients, 28 of their healthy first-degree relatives, and 19 normal control subjects. Schizophrenia patients and their relatives were significantly less accurate than normal control subjects on the spatial delayed response task but not on the sensorimotor control task. On both tasks, patients and relatives were slower to respond than the normal controls. There were no age or gender effects on accuracy, and working memory performance in schizophrenia patients was not significantly correlated with medication dosage. In summary, spatial working memory deficits that have been found in Caucasian schizophrenia patients and relatives were confirmed in this isolated Pacific Island family sample. These results suggest that spatial working memory deficits may be a potentially useful addition to the endophenotypic characterization of family members to be used in a comprehensive genome wide linkage analysis of these Palauan families. PMID:12210274

  8. Examining Event-Related Potential (ERP) Correlates of Decision Bias in Recognition Memory Judgments

    PubMed Central

    Hill, Holger; Windmann, Sabine

    2014-01-01

    Memory judgments can be based on accurate memory information or on decision bias (the tendency to report that an event is part of episodic memory when one is in fact unsure). Event related potentials (ERP) correlates are important research tools for elucidating the dynamics underlying memory judgments but so far have been established only for investigations of accurate old/new discrimination. To identify the ERP correlates of bias, and observe how these interact with ERP correlates of memory, we conducted three experiments that manipulated decision bias within participants via instructions during recognition memory tests while their ERPs were recorded. In Experiment 1, the bias manipulation was performed between blocks of trials (automatized bias) and compared to trial-by-trial shifts of bias in accord with an external cue (flexibly controlled bias). In Experiment 2, the bias manipulation was performed at two different levels of accurate old/new discrimination as the memory strength of old (studied) items was varied. In Experiment 3, the bias manipulation was added to another, bottom-up driven manipulation of bias induced via familiarity. In the first two Experiments, and in the low familiarity condition of Experiment 3, we found evidence of an early frontocentral ERP component at 320 ms poststimulus (the FN320) that was sensitive to the manipulation of bias via instruction, with more negative amplitudes indexing more liberal bias. By contrast, later during the trial (500–700 ms poststimulus), bias effects interacted with old/new effects across all three experiments. Results suggest that the decision criterion is typically activated early during recognition memory trials, and is integrated with retrieved memory signals and task-specific processing demands later during the trial. More generally, the findings demonstrate how ERPs can help to specify the dynamics of recognition memory processes under top-down and bottom-up controlled retrieval conditions. PMID

  9. The Role of Hippocampal Iron Concentration and Hippocampal Volume in Age-Related Differences in Memory

    PubMed Central

    Rodrigue, Karen M.; Daugherty, Ana M.; Haacke, E. Mark; Raz, Naftali

    2013-01-01

    The goal of this study was to examine the relationships between 2 age-sensitive indices of brain integrity—volume and iron concentration—and the associated age differences in memory performance. In 113 healthy adults (age 19–83 years), we measured the volume and estimated iron concentration in the hippocampus (HC), caudate nucleus (Cd), and primary visual cortex (VC) in vivo with T2* relaxation times, and assessed memory performance with multiple tests. We applied structural equation modeling to evaluate the contribution of individual differences in 2 indices of integrity, volume and T2*, to age-related memory variance. The results show that in healthy adults, age differences in memory can be explained in part by individual differences in HC volume that in turn are associated with differences in HC iron concentration. Lower memory scores were linked to smaller HC and higher HC iron concentration. No such associations were noted for Cd and VC. We conclude that the association between age-related declines in memory and reduced hippocampal volume may reflect the impact of oxidative stress related to increase in free iron concentration. Longitudinal follow-up is needed to test whether altered iron homeostasis in the HC is an early marker for age-related cognitive decline. PMID:22645251

  10. Training Working Memory in Childhood Enhances Coupling between Frontoparietal Control Network and Task-Related Regions

    PubMed Central

    Barnes, Jessica J.; Nobre, Anna Christina; Woolrich, Mark W.; Baker, Kate

    2016-01-01

    Working memory is a capacity upon which many everyday tasks depend and which constrains a child's educational progress. We show that a child's working memory can be significantly enhanced by intensive computer-based training, relative to a placebo control intervention, in terms of both standardized assessments of working memory and performance on a working memory task performed in a magnetoencephalography scanner. Neurophysiologically, we identified significantly increased cross-frequency phase amplitude coupling in children who completed training. Following training, the coupling between the upper alpha rhythm (at 16 Hz), recorded in superior frontal and parietal cortex, became significantly coupled with high gamma activity (at ∼90 Hz) in inferior temporal cortex. This altered neural network activity associated with cognitive skill enhancement is consistent with a framework in which slower cortical rhythms enable the dynamic regulation of higher-frequency oscillatory activity related to task-related cognitive processes. SIGNIFICANCE STATEMENT Whether we can enhance cognitive abilities through intensive training is one of the most controversial topics of cognitive psychology in recent years. This is particularly controversial in childhood, where aspects of cognition, such as working memory, are closely related to school success and are implicated in numerous developmental disorders. We provide the first neurophysiological account of how working memory training may enhance ability in childhood, using a brain recording technique called magnetoencephalography. We borrowed an analysis approach previously used with intracranial recordings in adults, or more typically in other animal models, called “phase amplitude coupling.” PMID:27559180

  11. Period1 gates the circadian modulation of memory-relevant signaling in mouse hippocampus by regulating the nuclear shuttling of the CREB kinase pP90RSK.

    PubMed

    Rawashdeh, Oliver; Jilg, Antje; Maronde, Erik; Fahrenkrug, Jan; Stehle, Jörg H

    2016-09-01

    Memory performance varies over a 24-h day/night cycle. While the detailed underlying mechanisms are yet unknown, recent evidence suggests that in the mouse hippocampus, rhythmic phosphorylation of mitogen-activated protein kinase (MAPK) and cyclic adenosine monophosphate response element-binding protein (CREB) are central to the circadian (~ 24 h) regulation of learning and memory. We recently identified the clock protein PERIOD1 (PER1) as a vehicle that translates information encoding time of day to hippocampal plasticity. We here elaborate how PER1 may gate the sensitivity of memory-relevant hippocampal signaling pathways. We found that in wild-type mice (WT), spatial learning triggers CREB phosphorylation only during the daytime, and that this effect depends on the presence of PER1. The time-of-day-dependent induction of CREB phosphorylation can be reproduced pharmacologically in acute hippocampal slices prepared from WT mice, but is absent in preparations made from Per1-knockout (Per1(-/-) ) mice. We showed that the PER1-dependent CREB phosphorylation is regulated downstream of MAPK. Stimulation of WT hippocampal neurons triggered the co-translocation of PER1 and the CREB kinase pP90RSK (pMAPK-activated ribosomal S6 kinase) into the nucleus. In hippocampal neurons from Per1(-/-) mice, however, pP90RSK remained perinuclear. A co-immunoprecipitation assay confirmed a high-affinity interaction between PER1 and pP90RSK. Knocking down endogenous PER1 in hippocampal cells inhibited adenylyl cyclase-dependent CREB activation. Taken together, the PER1-dependent modulation of cytoplasmic-to-nuclear signaling in the murine hippocampus provides a molecular explanation for how the circadian system potentially shapes a temporal framework for daytime-dependent memory performance, and adds a novel facet to the versatility of the clock gene protein PER1. We provide evidence that the circadian clock gene Period1 (Per1) regulates CREB phosphorylation in the mouse hippocampus

  12. Memory for trauma-related information in Holocaust survivors with PTSD.

    PubMed

    Golier, Julia A; Yehuda, Rachel; Lupien, Sonia J; Harvey, Philip D

    2003-12-01

    The impact of trauma-related information on memory performance in aging Holocaust survivors with post-traumatic stress disorder (PTSD) was evaluated. Explicit and implicit memory for neutral and Holocaust-related words was assessed in Holocaust survivors with PTSD (PTSD+, n=31), in Holocaust survivors without PTSD (PTSD-, n=17), and in healthy Jewish adults not exposed to the Holocaust (non-exposed, n=34) using the paired associates learning and word-stem completion tests, respectively. The PTSD+ group had significantly poorer paired associate recall than the PTSD- and non-exposed groups, and showed a significantly different response to the introduction of Holocaust-related words. The PTSD+ group recalled significantly more words from the Holocaust-related than the neutral word pairs, whereas word type had little effect on paired associate recall in the other two groups. In contrast, there were no group differences in implicit memory performance or in the effect of Holocaust-related words on implicit memory. Among Holocaust survivors, explicit recall of Holocaust-related word pairs was associated with intrusive PTSD symptoms. These results suggest that aging Holocaust survivors with PTSD preferentially form new associations with trauma-related stimuli as compared with neutral stimuli. The presence of such a disturbance of associative learning decades after the Holocaust may underlie the persistence of psychological symptoms and, in particular, the intrusive symptoms of PTSD. This trauma-related facilitation of explicit memory, together with generally poorer explicit memory, may help to explain the bi-directional nature of the memory impairments in PTSD. PMID:14656448

  13. Memory bias for schema-related stimuli in individuals with bulimia nervosa.

    PubMed

    Legenbauer, Tanja; Maul, Bärbel; Rühl, Ilka; Kleinstäuber, Maria; Hiller, Wolfgang

    2010-03-01

    This study investigates whether individuals with bulimia nervosa (BN) have a memory bias in relation to explicit memory (cued and free recall vs. verbal and pictorial recognition tasks). Twenty-five participants diagnosed with BN and 27 normal controls (NC) were exposed to body-related, food-related, and neutral TV commercials, and then recall and recognition rates were assessed. Poorer recognition and recall of body-related stimuli was found for BN in comparison to NC, suggesting a memory bias. Results are discussed in relation to previous studies, along with suggestions as to how future studies can gain more insight into dysfunctions in information processing that can lead to the maintenance of eating disorders. PMID:20099307

  14. Chunk formation in immediate memory and how it relates to data compression.

    PubMed

    Chekaf, Mustapha; Cowan, Nelson; Mathy, Fabien

    2016-10-01

    This paper attempts to evaluate the capacity of immediate memory to cope with new situations in relation to the compressibility of information likely to allow the formation of chunks. We constructed a task in which untrained participants had to immediately recall sequences of stimuli with possible associations between them. Compressibility of information was used to measure the chunkability of each sequence on a single trial. Compressibility refers to the recoding of information in a more compact representation. Although compressibility has almost exclusively been used to study long-term memory, our theory suggests that a compression process relying on redundancies within the structure of the list materials can occur very rapidly in immediate memory. The results indicated a span of about three items when the list had no structure, but increased linearly as structure was added. The amount of information retained in immediate memory was maximal for the most compressible sequences, particularly when information was ordered in a way that facilitated the compression process. We discuss the role of immediate memory in the rapid formation of chunks made up of new associations that did not already exist in long-term memory, and we conclude that immediate memory is the starting place for the reorganization of information. PMID:27367593

  15. Identity-related autobiographical memories and cultural life scripts in patients with Borderline Personality Disorder.

    PubMed

    Jørgensen, Carsten René; Berntsen, Dorthe; Bech, Morten; Kjølbye, Morten; Bennedsen, Birgit E; Ramsgaard, Stine B

    2012-06-01

    Disturbed identity is one of the defining characteristics of Borderline Personality Disorder manifested in a broad spectrum of dysfunctions related to the self, including disturbances in meaning-generating self-narratives. Autobiographical memories are memories of personal events that provide crucial building-blocks in our construction of a life-story, self-concept, and a meaning-generating narrative identity. The cultural life script represents culturally shared expectations as to the order and timing of life events in a prototypical life course within a given culture. It is used to organize one's autobiographical memories. Here, 17 BPD-patients, 14 OCD-patients, and 23 non-clinical controls generated three important autobiographical memories and their conceptions of the cultural life script. BPD-patients reported substantially more negative memories, fewer of their memories were of prototypical life script events, their memory narratives were less coherent and more disoriented, and the overall typicality of their life scripts was lower as compared with the other two groups. PMID:22356875

  16. Working Memory and Impulsivity Predict Marijuana-Related Problems Among Frequent Users

    PubMed Central

    Day, Anne M.; Metrik, Jane; Spillane, Nichea S.; Kahler, Christopher W.

    2012-01-01

    Background Although marijuana is the most commonly used illicit substance in the US, only a small portion of users go on to develop dependence, suggesting that there are substantial individual differences in vulnerability to marijuana-related problems among users. Deficits in working memory and high trait impulsivity are two factors that may place marijuana users at increased risk for experiencing related problems. Methods Using baseline data from an experimental study that recruited 104 frequent marijuana users (M=71.86% of prior 60 days, SD=22%), we examined the associations of working memory and trait impulsivity with marijuana-related problems. Results Lower working memory, as measured by Trail Making Test B, but not short-term memory capacity, predicted more marijuana-related problems. Higher trait impulsivity scores were independently associated with greater number of problems. Conclusions Results suggest that marijuana users with reduced executive cognitive ability are more susceptible to developing problems related to their use. Trait impulsivity and executive working memory appear to be independent risk factors for experiencing marijuana-related problems. PMID:23312340

  17. Disruption of Relational Processing Underlies Poor Memory for Order

    ERIC Educational Resources Information Center

    Jonker, Tanya R.; MacLeod, Colin M.

    2015-01-01

    McDaniel and Bugg (2008) proposed that relatively uncommon stimuli and encoding tasks encourage elaborative encoding of individual items (item-specific processing), whereas relatively typical or common encoding tasks encourage encoding of associations among list items (relational processing). It is this relational processing that is thought to…

  18. Event-related rTMS at encoding affects differently deep and shallow memory traces.

    PubMed

    Innocenti, Iglis; Giovannelli, Fabio; Cincotta, Massimo; Feurra, Matteo; Polizzotto, Nicola R; Bianco, Giovanni; Cappa, Stefano F; Rossi, Simone

    2010-10-15

    The "level of processing" effect is a classical finding of the experimental psychology of memory. Actually, the depth of information processing at encoding predicts the accuracy of the subsequent episodic memory performance. When the incoming stimuli are analyzed in terms of their meaning (semantic, or deep, encoding), the memory performance is superior with respect to the case in which the same stimuli are analyzed in terms of their perceptual features (shallow encoding). As suggested by previous neuroimaging studies and by some preliminary findings with transcranial magnetic stimulation (TMS), the left prefrontal cortex may play a role in semantic processing requiring the allocation of working memory resources. However, it still remains unclear whether deep and shallow encoding share or not the same cortical networks, as well as how these networks contribute to the "level of processing" effect. To investigate the brain areas casually involved in this phenomenon, we applied event-related repetitive TMS (rTMS) during deep (semantic) and shallow (perceptual) encoding of words. Retrieval was subsequently tested without rTMS interference. RTMS applied to the left dorsolateral prefrontal cortex (DLPFC) abolished the beneficial effect of deep encoding on memory performance, both in terms of accuracy (decrease) and reaction times (increase). Neither accuracy nor reaction times were instead affected by rTMS to the right DLPFC or to an additional control site excluded by the memory process (vertex). The fact that online measures of semantic processing at encoding were unaffected suggests that the detrimental effect on memory performance for semantically encoded items took place in the subsequent consolidation phase. These results highlight the specific causal role of the left DLPFC among the wide left-lateralized cortical network engaged by long-term memory, suggesting that it probably represents a crucial node responsible for the improved memory performance induced by

  19. The development of control processes supporting source memory discrimination as revealed by event-related potentials.

    PubMed

    de Chastelaine, Marianne; Friedman, David; Cycowicz, Yael M

    2007-08-01

    Improvement in source memory performance throughout childhood is thought to be mediated by the development of executive control. As postretrieval control processes may be better time-locked to the recognition response rather than the retrieval cue, the development of processes underlying source memory was investigated with both stimulus- and response-locked event-related potentials (ERPs). These were recorded in children, adolescents, and adults during a recognition memory exclusion task. Green- and red-outlined pictures were studied, but were tested in black outline. The test requirement was to endorse old items shown in one study color ("targets") and to reject new items along with old items shown in the alternative study color ("nontargets"). Source memory improved with age. All age groups retrieved target and nontarget memories as reflected by reliable parietal episodic memory (EM) effects, a stimulus-locked ERP correlate of recollection. Response-locked ERPs to targets and nontargets diverged in all groups prior to the response, although this occurred at an increasingly earlier time point with age. We suggest these findings reflect the implementation of attentional control mechanisms to enhance target memories and facilitate response selection with the greatest and least success, respectively, in adults and children. In adults only, response-locked ERPs revealed an early-onsetting parietal negativity for nontargets, but not for targets. This was suggested to reflect adults' ability to consistently inhibit prepotent target responses for nontargets. The findings support the notion that the development of source memory relies on the maturation of control processes that serve to enhance accurate selection of task-relevant memories. PMID:17651003

  20. A 600-µW ultra-low-power associative processor for image pattern recognition employing magnetic tunnel junction-based nonvolatile memories with autonomic intelligent power-gating scheme

    NASA Astrophysics Data System (ADS)

    Ma, Yitao; Miura, Sadahiko; Honjo, Hiroaki; Ikeda, Shoji; Hanyu, Takahiro; Ohno, Hideo; Endoh, Tetsuo

    2016-04-01

    A novel associative processor using magnetic tunnel junction (MTJ)-based nonvolatile memories has been proposed and fabricated under a 90 nm CMOS/70 nm perpendicular-MTJ (p-MTJ) hybrid process for achieving the exceptionally low-power performance of image pattern recognition. A four-transistor 2-MTJ (4T-2MTJ) spin transfer torque magnetoresistive random access memory was adopted to completely eliminate the standby power. A self-directed intelligent power-gating (IPG) scheme specialized for this associative processor is employed to optimize the operation power by only autonomously activating currently accessed memory cells. The operations of a prototype chip at 20 MHz are demonstrated by measurement. The proposed processor can successfully carry out single texture pattern matching within 6.5 µs using 128-dimension bag-of-feature patterns, and the measured average operation power of the entire processor core is only 600 µW. Compared with the twin chip designed with 6T static random access memory, 91.2% power reductions are achieved. More than 88.0% power reductions are obtained compared with the latest associative memories. The further power performance analysis is discussed in detail, which verifies the special superiority of the proposed processor in power consumption for large-capacity memory-based VLSI systems.

  1. Modifications of recognition memory processes in preterm children: an event-related potential study.

    PubMed

    Kipp, Kerstin H; Mecklinger, Axel; Brunnemann, Nicole; Shamdeen, Mohammed G; Meng-Hentschel, Juliane; Gortner, Ludwig

    2015-01-01

    Prematurity may cause hippocampal compromise. Therefore, hippocampus-dependent memory processes (recollection-based retrieval) may be more impaired than hippocampus-independent processes (familiarity-based retrieval). The memory of 18 children born preterm with reduced hippocampal volumes, without neonatal complications (weeks of gestation < 34, weight < 1,600 g), and 15 controls (8-10 years) was tested using an item recognition task. While groups were equal in memory performance, dissociation was found: The event-related potential (ERP) correlate of familiarity was intact in the preterm group, whereas the correlate of recollection was attenuated. A follow-up experiment ruled out that this was due to general cognitive deficits. Furthermore, gestational age correlated with the ERP index of recollection. Thus, recognition memory in preterm children may be characterized by a compensation of attenuated recollection by familiarity. PMID:25521668

  2. Late memory-related genes in the hippocampus revealed by RNA fingerprinting

    PubMed Central

    Cavallaro, Sebastiano; Meiri, Noam; Yi, Chu-Li; Musco, Simone; Ma, Wu; Goldberg, Jesse; Alkon, Daniel L.

    1997-01-01

    Although long-term memory is thought to require a cellular program of gene expression and increased protein synthesis, the identity of proteins critical for associative memory is largely unknown. We used RNA fingerprinting to identify candidate memory-related genes (MRGs), which were up-regulated in the hippocampus of water maze-trained rats, a brain area that is critically involved in spatial learning. Two of the original 10 candidate genes implicated by RNA fingerprinting, the rat homolog of the ryanodine receptor type-2 and glutamate dehydrogenase (EC 1.4.1.3), were further investigated by Northern blot analysis, reverse transcription–PCR, and in situ hybridization and confirmed as MRGs with distinct temporal and regional expression. Successive RNA screening as illustrated here may help to reveal a spectrum of MRGs as they appear in distinct domains of memory storage. PMID:9275181

  3. Age-Related Declines in Visuospatial Working Memory Correlate With Deficits in Explicit Motor Sequence Learning

    PubMed Central

    Bo, J.; Borza, V.

    2009-01-01

    Numerous studies have shown that older adults exhibit deficits in motor sequence learning, but the mechanisms underlying this effect remain unclear. Our recent work has shown that visuospatial working-memory capacity predicts the rate of motor sequence learning and the length of motor chunks formed during explicit sequence learning in young adults. In the current study, we evaluate whether age-related deficits in working memory explain the reduced rate of motor sequence learning in older adults. We found that older adults exhibited a correlation between visuospatial working-memory capacity and motor sequence chunk length, as we observed previously in young adults. In addition, older adults exhibited an overall reduction in both working-memory capacity and motor chunk length compared with that of young adults. However, individual variations in visuospatial working-memory capacity did not correlate with the rate of learning in older adults. These results indicate that working memory declines with age at least partially explain age-related differences in explicit motor sequence learning. PMID:19726728

  4. Age-related declines in visuospatial working memory correlate with deficits in explicit motor sequence learning.

    PubMed

    Bo, J; Borza, V; Seidler, R D

    2009-11-01

    Numerous studies have shown that older adults exhibit deficits in motor sequence learning, but the mechanisms underlying this effect remain unclear. Our recent work has shown that visuospatial working-memory capacity predicts the rate of motor sequence learning and the length of motor chunks formed during explicit sequence learning in young adults. In the current study, we evaluate whether age-related deficits in working memory explain the reduced rate of motor sequence learning in older adults. We found that older adults exhibited a correlation between visuospatial working-memory capacity and motor sequence chunk length, as we observed previously in young adults. In addition, older adults exhibited an overall reduction in both working-memory capacity and motor chunk length compared with that of young adults. However, individual variations in visuospatial working-memory capacity did not correlate with the rate of learning in older adults. These results indicate that working memory declines with age at least partially explain age-related differences in explicit motor sequence learning. PMID:19726728

  5. Disruption of Alcohol-Related Memories by mTORC1 Inhibition Prevents Relapse

    PubMed Central

    Barak, Segev; Liu, Feng; Hamida, Sami Ben; Yowell, Quinn V.; Neasta, Jeremie; Kharazia, Viktor; Janak, Patricia H.; Ron, Dorit

    2013-01-01

    Relapse to alcohol abuse is a critical clinical issue, frequently caused by cue-induced drug craving. Therefore, disruption of the memory for the cue-alcohol association is expected to prevent relapse. It is increasingly accepted that memories become labile and erasable soon after their reactivation through retrieval, during a memory reconsolidation process that depends on protein synthesis. Here, we show that reconsolidation of alcohol-related memories triggered by the sensory properties of alcohol itself (odor and taste) activates mammalian target of rapamycin complex 1 (mTORC1) in select amygdalar and cortical regions in rats, resulting in increased levels of several synaptic proteins. Furthermore, systemic or central amygdalar (CeA) inhibition of mTORC1 during reconsolidation disrupts alcohol-cue associated memories, leading to a long-lasting suppression of relapse. Our findings provide evidence that the mTORC1 pathway and its downstream substrates play a crucial role in alcohol-related memory reconsolidation, and highlight this pathway as a therapeutic target to prevent relapse. PMID:23792945

  6. Evaluation of clinical IMRT treatment planning using the GATE Monte Carlo simulation platform for absolute and relative dose calculations

    SciTech Connect

    Benhalouche, S.; Le Maitre, A.; Visvikis, D.; Pradier, O.; Boussion, N.

    2013-02-15

    Purpose: The objective of this study was to evaluate and validate the use of the Geant4 application for emission tomography (GATE) Monte Carlo simulation platform for clinical intensity modulated radiotherapy (IMRT) dosimetry studies. Methods: The first step consisted of modeling a 6 MV photon beam linear accelerator (LINAC), with its corresponding validation carried out using percent depth dose evaluation, transverse profiles, tissue phantom ratio, and output factor on water phantom. The IMRT evaluation was performed by comparing simulation and measurements in terms of absolute and relative doses using IMRT dedicated quality assurance phantoms considering seven different patient datasets. Results: Concerning the LINAC simulated model validation tissue phantom ratios at 20 and 10 cm in water TPR{sub 10}{sup 20} obtained from GATE and measurements were 0.672 {+-} 0.063 and 0.675, respectively. In terms of percent depth dose and transverse profiles, error ranges were, respectively: 1.472%{+-} 0.285% and 4.827%{+-} 1.323% for field size of 4 Multiplication-Sign 4, 5 Multiplication-Sign 5, 10 Multiplication-Sign 10, 15 Multiplication-Sign 15, 20 Multiplication-Sign 20, 25 Multiplication-Sign 25, 30 Multiplication-Sign 30, and 40 Multiplication-Sign 40 cm{sup 2}. Most errors were observed at the edge of radiation fields because of higher dose gradient in these areas. Output factors showed good agreement between simulation and measurements with a maximum error of 1.22%. Finally, for IMRT simulations considering seven patient datasets, GATE provided good results with a relative error of 0.43%{+-} 0.25% on absolute dose between simulated and measured beams (measurements at the isocenter, volume 0.125 cm{sup 3}). Planar dose comparisons were also performed using gamma-index analysis. For the whole set of beams considered the mean gamma-index value was 0.497 {+-} 0.152 and 90.8%{+-} 3.6% of the evaluated dose points satisfied the 5%/ 4 mm criterion. Conclusions: These

  7. Personality traits and autobiographical memory: Openness is positively related to the experience and usage of recollections.

    PubMed

    Rasmussen, Anne S; Berntsen, Dorthe

    2010-10-01

    We examined the relationship between the Five-Factor Model of personality and the experience and overall usage of autobiographical memory in two studies. In both studies we found that Openness was related to the directive and self functions of overall usage. In addition, Openness was related to the vividness, reliving, coherence, and centrality of event to the person's identity and life story of concrete memories in Study 2, whereas this was not found in Study 1. For the remaining "Big Five" personality traits the results were less consistent across studies. Neuroticism was related to the self function in Study 1, but also to the directive function as well as to negative affect of concrete memories in Study 1. Extraversion was positively related to the social function as well as to conversational rehearsal of memories in Study 1, but this was also not replicated in Study 2. Finally, in both studies there were no significant relationships with regard to Agreeableness and Conscientiousness. Overall, the findings replicate and extend previous work showing a positive relationship between Openness and the experience and overall usage of autobiographical memory, whereas the roles for the remaining "Big Five" are less clear. PMID:20924950

  8. Motor Skills Enhance Procedural Memory Formation and Protect against Age-Related Decline.

    PubMed

    Müller, Nils C J; Genzel, Lisa; Konrad, Boris N; Pawlowski, Marcel; Neville, David; Fernández, Guillén; Steiger, Axel; Dresler, Martin

    2016-01-01

    The ability to consolidate procedural memories declines with increasing age. Prior knowledge enhances learning and memory consolidation of novel but related information in various domains. Here, we present evidence that prior motor experience-in our case piano skills-increases procedural learning and has a protective effect against age-related decline for the consolidation of novel but related manual movements. In our main experiment, we tested 128 participants with a sequential finger-tapping motor task during two sessions 24 hours apart. We observed enhanced online learning speed and offline memory consolidation for piano players. Enhanced memory consolidation was driven by a strong effect in older participants, whereas younger participants did not benefit significantly from prior piano experience. In a follow up independent control experiment, this compensatory effect of piano experience was not visible after a brief offline period of 30 minutes, hence requiring an extended consolidation window potentially involving sleep. Through a further control experiment, we rejected the possibility that the decreased effect in younger participants was caused by training saturation. We discuss our results in the context of the neurobiological schema approach and suggest that prior experience has the potential to rescue memory consolidation from age-related cognitive decline. PMID:27333186

  9. Motor Skills Enhance Procedural Memory Formation and Protect against Age-Related Decline

    PubMed Central

    Müller, Nils C. J.; Genzel, Lisa; Konrad, Boris N.; Pawlowski, Marcel; Neville, David; Fernández, Guillén; Steiger, Axel

    2016-01-01

    The ability to consolidate procedural memories declines with increasing age. Prior knowledge enhances learning and memory consolidation of novel but related information in various domains. Here, we present evidence that prior motor experience–in our case piano skills–increases procedural learning and has a protective effect against age-related decline for the consolidation of novel but related manual movements. In our main experiment, we tested 128 participants with a sequential finger-tapping motor task during two sessions 24 hours apart. We observed enhanced online learning speed and offline memory consolidation for piano players. Enhanced memory consolidation was driven by a strong effect in older participants, whereas younger participants did not benefit significantly from prior piano experience. In a follow up independent control experiment, this compensatory effect of piano experience was not visible after a brief offline period of 30 minutes, hence requiring an extended consolidation window potentially involving sleep. Through a further control experiment, we rejected the possibility that the decreased effect in younger participants was caused by training saturation. We discuss our results in the context of the neurobiological schema approach and suggest that prior experience has the potential to rescue memory consolidation from age-related cognitive decline. PMID:27333186

  10. The Relation between Attention to the Incidental Context and Memory for Words in Children and Adults.

    ERIC Educational Resources Information Center

    Ackerman, Brian P.

    1986-01-01

    Five experiments examined the developmental relation between attention to target and context information and target memory among second and fifth graders and college adults. Results show that when the context is meaningfully related to target information, adults are less selective than children and are more likely to attend to context information.…

  11. Verbal Memory Deficits in Relation to Organization Strategy in High- and Low-Functioning Autistic Children

    ERIC Educational Resources Information Center

    Cheung, Mei-chun; Chan, Agnes S.; Sze, Sophia L.; Leung, Winnie W.; To, Cho Yee

    2010-01-01

    The present study examined the verbal memory profile and its relation to organizational strategies in high-functioning (Hi-AUT) and low-functioning (Lo-AUT) children with autism. Twenty-two Hi-AUT and 16 Lo-AUT, and 22 age-, gender- and handedness-matched normal children (NC) were required to remember a list of semantically related words for…

  12. Morphological Information and Memory Resources in Children's Processing of Relative Clauses in German

    ERIC Educational Resources Information Center

    Arosio, Fabrizio; Yatsushiro, Kazuko; Forgiarini, Matteo; Guasti, Maria Teresa

    2012-01-01

    We investigated the processing of agreement marking and case marking in the comprehension of German relative clauses in 48 seven-year-old monolingual German-speaking children in a picture selection task. We examined the relation between the effectiveness of these different morphological cues and individual memory resources as measured by a…

  13. Differences in Processing of Taxonomic and Sequential Relations in Semantic Memory: An fMRI Investigation

    ERIC Educational Resources Information Center

    Kuchinke, Lars; van der Meer, Elke; Krueger, Frank

    2009-01-01

    Conceptual knowledge of our world is represented in semantic memory in terms of concepts and semantic relations between concepts. We used functional magnetic resonance imaging (fMRI) to examine the cortical regions underlying the processing of sequential and taxonomic relations. Participants were presented verbal cues and performed three tasks:…

  14. Thinking about the Future Early in Life: The Role of Relational Memory

    ERIC Educational Resources Information Center

    Richmond, Jenny L.; Pan, Rose

    2013-01-01

    The constructive episodic simulation hypothesis suggests that we imagine possible future events by flexibly recombining details of past experiences to produce novel scenarios. Here we tested this hypothesis by determining whether episodic future thinking is related to relational memory ability during the preschool years. Children (3- to…

  15. Working Memory Is Related to Perceptual Processing: A Case from Color Perception

    ERIC Educational Resources Information Center

    Allen, Elizabeth C.; Beilock, Sian L.; Shevell, Steven K.

    2011-01-01

    We explored the relation between individual differences in working memory (WM) and color constancy, the phenomenon of color perception that allows us to perceive the color of an object as relatively stable under changes in illumination. Successive color constancy (measured by first viewing a colored surface under a particular illumination and…

  16. IFN-γ differentially modulates memory-related processes under basal and chronic stressor conditions

    PubMed Central

    Litteljohn, Darcy; Nelson, Eric; Hayley, Shawn

    2014-01-01

    Cytokines are inflammatory messengers that orchestrate the brain’s response to immunological challenges, as well as possibly even toxic and psychological insults. We previously reported that genetic ablation of the pro-inflammatory cytokine, interferon-gamma (IFN-γ), attenuated some of the corticosteroid, cytokine, and limbic dopaminergic variations induced by 6 weeks of exposure to an unpredictable psychologically relevant stressor. Presently, we sought to determine whether a lack of IFN-γ would likewise modify the impact of chronic stress on hippocampus-dependent memory function and related neurotransmitter and neurotrophin signaling systems. As predicted, chronic stress impaired spatial recognition memory (Y-maze task) in the wild-type animals. In contrast, though the IFN-γ knockouts (KOs) showed memory disturbances in the basal state, under conditions of chronic stress these mice actually exhibited facilitated memory performance. Paralleling these findings, while overall the KOs displayed altered noradrenergic and/or serotonergic activity in the hippocampus and locus coeruleus, norepinephrine utilization in both of these memory-related brain regions was selectively increased among the chronically stressed KOs. However, contrary to our expectations, neither IFN-γ deletion nor chronic stressor exposure significantly affected nucleus accumbens dopaminergic neurotransmission or hippocampal brain-derived neurotrophic factor protein expression. These findings add to a growing body of evidence implicating cytokines in the often differential regulation of neurobehavioral processes in health and disease. Whereas in the basal state IFN-γ appears to be involved in sustaining memory function and the activity of related brain monoamine systems, in the face of ongoing psychologically relevant stress the cytokine may, in fact, act to restrict potentially adaptive central noradrenergic and spatial memory responses. PMID:25477784

  17. Event-related potential correlates of long-term memory for briefly presented faces.

    PubMed

    Joyce, Carrie A; Kutas, Marta

    2005-05-01

    Electrophysiological studies have investigated the nature of face recognition in a variety of paradigms; some have contrasted famous and novel faces in explicit memory paradigms, others have repeated faces to examine implicit memory/priming. If the general finding that implicit memory can last for up to several months also holds for novel faces, a reliable measure of it could have practical application for eyewitness testimony, given that explicit measures of eyewitness memory have at times proven fallible. The current study aimed to determine whether indirect behavioral and electrophysiological measures might yield reliable estimates of face memory over longer intervals than have typically been obtained with priming manipulations. Participants were shown 192 faces and then tested for recognition at four test delays ranging from immediately up to 1 week later. Three event-related brain potential components (e.g., N250r, N400f, and LPC) varied with memory measures although only the N250r varied regardless of explicit recognition, that is, with both repetition and recognition. PMID:15904542

  18. Developmental dyscalculia is related to visuo-spatial memory and inhibition impairment☆

    PubMed Central

    Szucs, Denes; Devine, Amy; Soltesz, Fruzsina; Nobes, Alison; Gabriel, Florence

    2013-01-01

    Developmental dyscalculia is thought to be a specific impairment of mathematics ability. Currently dominant cognitive neuroscience theories of developmental dyscalculia suggest that it originates from the impairment of the magnitude representation of the human brain, residing in the intraparietal sulcus, or from impaired connections between number symbols and the magnitude representation. However, behavioral research offers several alternative theories for developmental dyscalculia and neuro-imaging also suggests that impairments in developmental dyscalculia may be linked to disruptions of other functions of the intraparietal sulcus than the magnitude representation. Strikingly, the magnitude representation theory has never been explicitly contrasted with a range of alternatives in a systematic fashion. Here we have filled this gap by directly contrasting five alternative theories (magnitude representation, working memory, inhibition, attention and spatial processing) of developmental dyscalculia in 9–10-year-old primary school children. Participants were selected from a pool of 1004 children and took part in 16 tests and nine experiments. The dominant features of developmental dyscalculia are visuo-spatial working memory, visuo-spatial short-term memory and inhibitory function (interference suppression) impairment. We hypothesize that inhibition impairment is related to the disruption of central executive memory function. Potential problems of visuo-spatial processing and attentional function in developmental dyscalculia probably depend on short-term memory/working memory and inhibition impairments. The magnitude representation theory of developmental dyscalculia was not supported. PMID:23890692

  19. Context Memory Decline in Middle Aged Adults is Related to Changes in Prefrontal Cortex Function.

    PubMed

    Kwon, Diana; Maillet, David; Pasvanis, Stamatoula; Ankudowich, Elizabeth; Grady, Cheryl L; Rajah, M Natasha

    2016-06-01

    The ability to encode and retrieve spatial and temporal contextual details of episodic memories (context memory) begins to decline at midlife. In the current study, event-related fMRI was used to investigate the neural correlates of context memory decline in healthy middle aged adults (MA) compared with young adults (YA). Participants were scanned while performing easy and hard versions of spatial and temporal context memory tasks. Scans were obtained at encoding and retrieval. Significant reductions in context memory retrieval accuracy were observed in MA, compared with YA. The fMRI results revealed that overall, both groups exhibited similar patterns of brain activity in parahippocampal cortex, ventral occipito-temporal regions and prefrontal cortex (PFC) during encoding. In contrast, at retrieval, there were group differences in ventral occipito-temporal and PFC activity, due to these regions being more activated in MA, compared with YA. Furthermore, only in YA, increased encoding activity in ventrolateral PFC, and increased retrieval activity in occipital cortex, predicted increased retrieval accuracy. In MA, increased retrieval activity in anterior PFC predicted increased retrieval accuracy. These results suggest that there are changes in PFC contributions to context memory at midlife. PMID:25882039

  20. Developmental dyscalculia is related to visuo-spatial memory and inhibition impairment.

    PubMed

    Szucs, Denes; Devine, Amy; Soltesz, Fruzsina; Nobes, Alison; Gabriel, Florence

    2013-01-01

    Developmental dyscalculia is thought to be a specific impairment of mathematics ability. Currently dominant cognitive neuroscience theories of developmental dyscalculia suggest that it originates from the impairment of the magnitude representation of the human brain, residing in the intraparietal sulcus, or from impaired connections between number symbols and the magnitude representation. However, behavioral research offers several alternative theories for developmental dyscalculia and neuro-imaging also suggests that impairments in developmental dyscalculia may be linked to disruptions of other functions of the intraparietal sulcus than the magnitude representation. Strikingly, the magnitude representation theory has never been explicitly contrasted with a range of alternatives in a systematic fashion. Here we have filled this gap by directly contrasting five alternative theories (magnitude representation, working memory, inhibition, attention and spatial processing) of developmental dyscalculia in 9-10-year-old primary school children. Participants were selected from a pool of 1004 children and took part in 16 tests and nine experiments. The dominant features of developmental dyscalculia are visuo-spatial working memory, visuo-spatial short-term memory and inhibitory function (interference suppression) impairment. We hypothesize that inhibition impairment is related to the disruption of central executive memory function. Potential problems of visuo-spatial processing and attentional function in developmental dyscalculia probably depend on short-term memory/working memory and inhibition impairments. The magnitude representation theory of developmental dyscalculia was not supported. PMID:23890692

  1. Double dissociation between rules and memory in music: An event-related potential study

    PubMed Central

    Miranda, Robbin A.; Ullman, Michael T.

    2007-01-01

    Language and music share a number of characteristics. Crucially, both domains depend on both rules and memorized representations. Double dissociations between the neurocognition of rule-governed and memory-based knowledge have been found in language but not music. Here, the neural bases of both of these aspects of music were examined with an event-related potential (ERP) study of note violations in melodies. Rule-only violations consisted of out-of-key deviant notes that violated tonal harmony rules in novel (unfamiliar) melodies. Memory-only violations consisted of in-key deviant notes in familiar well-known melodies; these notes followed musical rules but deviated from the actual melodies. Finally, out-of-key notes in familiar well-known melodies constituted violations of both rules and memory. All three conditions were presented, within-subjects, to healthy young adults, half musicians and half non-musicians. The results revealed a double dissociation, independent of musical training, between rules and memory: both rule violation conditions, but not the memory-only violations, elicited an early, somewhat right-lateralized anterior-central negativity (ERAN), consistent with previous studies of rule violations in music, and analogous to the early left-lateralized anterior negativities elicited by rule violations in language. In contrast, both memory violation conditions, but not the rule-only violation, elicited a posterior negativity that might be characterized as an N400, an ERP component that depends, at least in part, on the processing of representations stored in long-term memory, both in language and in other domains. The results suggest that the neurocognitive rule/memory dissociation extends from language to music, further strengthening the similarities between the two domains. PMID:17855126

  2. Double dissociation between rules and memory in music: an event-related potential study.

    PubMed

    Miranda, Robbin A; Ullman, Michael T

    2007-11-01

    Language and music share a number of characteristics. Crucially, both domains depend on both rules and memorized representations. Double dissociations between the neurocognition of rule-governed and memory-based knowledge have been found in language but not music. Here, the neural bases of both of these aspects of music were examined with an event-related potential (ERP) study of note violations in melodies. Rule-only violations consisted of out-of-key deviant notes that violated tonal harmony rules in novel (unfamiliar) melodies. Memory-only violations consisted of in-key deviant notes in familiar well-known melodies; these notes followed musical rules but deviated from the actual melodies. Finally, out-of-key notes in familiar well-known melodies constituted violations of both rules and memory. All three conditions were presented, within-subjects, to healthy young adults, half musicians and half non-musicians. The results revealed a double dissociation, independent of musical training, between rules and memory: both rule violation conditions, but not the memory-only violations, elicited an early, somewhat right-lateralized anterior-central negativity (ERAN), consistent with previous studies of rule violations in music, and analogous to the early left-lateralized anterior negativities elicited by rule violations in language. In contrast, both memory violation conditions, but not the rule-only violation, elicited a posterior negativity that might be characterized as an N400, an ERP component that depends, at least in part, on the processing of representations stored in long-term memory, both in language and in other domains. The results suggest that the neurocognitive rule/memory dissociation extends from language to music, further strengthening the similarities between the two domains. PMID:17855126

  3. Unitization improves source memory in older adults: An event-related potential study.

    PubMed

    Zheng, Zhiwei; Li, Juan; Xiao, Fengqiu; Ren, Weicong; He, Rongqiao

    2016-08-01

    Aging-related decline in episodic memory, particularly in associative memory, is attributed to an impaired recollection of the specific details of a study episode. Fortunately, familiarity is relatively preserved in older adults. Previous studies have indicated that unitization is a specialized form of learning that increases the contribution of familiarity to associative retrieval. Here we examined whether older adults' associative memory could be improved when employing an encoding strategy that encouraged unitization. Young and older adults encoded items and background colors either in a unitized condition (i.e., by imagining the color as an internal feature of the item) or in a non-unitized condition (i.e., by imagining the color as a contextual feature of the item). The participants then performed a source recognition test. The effects of unitization on the neural correlates of familiarity were measured by event-related potentials (ERPs). The age differences in source memory performance were lower in the unitized condition than in the non-unitized condition. The older adults only demonstrated neural correlates of familiarity-based source recognition in the unitized condition. These findings suggest that a unitized encoding strategy could improve source memory performance in older adults by enhancing the involvement of familiarity in source recognition. PMID:27343684

  4. Memory functioning in social drinkers: a study of event-related potentials.

    PubMed

    Fox, A M; Michie, P T; Coltheart, M; Solowij, N

    1995-05-01

    Verbal memory functioning was assessed in light and heavy social drinkers by recording event-related potentials in subjects instructed to memorize lists of words using either repetition or elaborative learning strategies. Although overall performance did not differ significantly between light and heavy drinkers, heavy drinkers showed reduced within-list organization compared with light drinkers. There were statistically significant differences in the event-related potential indices of memory functioning elicited during complex elaborative processing which were consistent with decreased within-list organization in heavy drinkers. PMID:7545984

  5. Personal Memories for Remote Historical Events: Accuracy and Clarity of Flashbulb Memories Related to World War II

    ERIC Educational Resources Information Center

    Berntsen, Dorthe; Thomsen, Dorthe K.

    2005-01-01

    One hundred forty-five Danes between 72 and 89 years of age were asked for their memories of their reception of the news of the Danish occupation (April 1940) and liberation (May 1945) and for their most negative and most positive personal memories from World War II. Almost all reported memories for the invasion and liberation. Their answers to…

  6. I owe you: age-related similarities and differences in associative memory for gains and losses.

    PubMed

    Castel, Alan D; Friedman, Michael C; McGillivray, Shannon; Flores, Cynthia C; Murayama, Kou; Kerr, Tyson; Drolet, Aimee

    2016-09-01

    Older adults often experience associative memory impairments but can sometimes remember important information. The current experiments investigate potential age-related similarities and differences associate memory for gains and losses. Younger and older participants were presented with faces and associated dollar amounts, which indicated how much money the person "owed" the participant, and were later given a cued recall test for the dollar amount. Experiment 1 examined face-dollar amount pairs while Experiment 2 included negative dollar amounts to examine both gains and losses. While younger adults recalled more information relative to older adults, both groups were more accurate in recalling the correct value associated with high-value faces compared to lower-value faces and remembered gist-information about the values. However, negative values (losses) did not have a strong impact on recall among older adults versus younger adults, illustrating important associative memory differences between younger and older adults. PMID:26847137

  7. Glutamatergic treatment strategies for age-related memory disorders.

    PubMed

    Müller, W E; Scheuer, K; Stoll, S

    1994-01-01

    Age-related changes of N-methyl-D-aspartate (NMDA) receptors have been found in cortical areas and in the hippocampus of many species. On the basis of a variety of experimental observations it has been suggested that the decrease of NMDA receptor density might be one of the causative factors of the cognitive decline with aging. Based on these findings several strategies have been developed to improve cognition by compensating the NMDA receptor deficits in aging. The most promising approaches are the indirect activation of glutamatergic neurotransmission by agonists of the glycine site or the restoration of the age-related deficit of receptor density by several nootropics. PMID:7997073

  8. Functional connectivity change across multiple cortical networks relates to episodic memory changes in aging.

    PubMed

    Fjell, Anders M; Sneve, Markus H; Grydeland, Håkon; Storsve, Andreas B; de Lange, Ann-Marie Glasø; Amlien, Inge K; Røgeberg, Ole J; Walhovd, Kristine B

    2015-12-01

    A major task of contemporary cognitive neuroscience of aging is to explain why episodic memory declines. Change in resting-state functional connectivity (rsFC) could be a mechanism accounting for reduced function. We addressed this through 3 studies. In study 1, 119 healthy participants (20-83 years) were followed for 3.5 years with verbal recall testing and magnetic resonance imaging. Independent of atrophy, recall change was related to change in rsFC in anatomically widespread areas. Striking age-effects were observed in that a positive relationship between rsFC and memory characterized older participants while a negative relationship was seen among the younger and middle-aged. This suggests that cognitive consequences of rsFC change are not stable across age. In study 2 and 3, the age-dependent differences in rsFC-memory relationship were replicated by use of a simulation model (study 2) and by a cross-sectional experimental recognition memory task (study 3). In conclusion, memory changes were related to altered rsFC in an age-dependent manner, and future research needs to detail the mechanisms behind age-varying relationships. PMID:26363813

  9. CPEB4 Knockout Mice Exhibit Normal Hippocampus-Related Synaptic Plasticity and Memory

    PubMed Central

    Chou, Hsin-Jung; Liu, Ta-Jen; Lee, Ping-Tao; Huang, Wen-Hsuan; Tsou, Yueh-Liang; Huang, Yi-Shuian

    2013-01-01

    Regulated RNA translation is critical to provide proteins needed to maintain persistent modification of synaptic strength, which underlies the molecular basis of long-term memory (LTM). Cytoplasmic polyadenylation element-binding proteins (CPEBs) are sequence-specific RNA-binding proteins and regulate translation in various tissues. All four CPEBs in vertebrates are expressed in the brain, including the hippocampal neurons, suggesting their potential roles in translation-dependent plasticity and memory. Although CPEB1 and CPEB3 have been shown to control specific kinds of hippocampus-related LTM, the role of CPEB2 and CPEB4 in learning and memory remains elusive. Thus, we generated CPEB4 knockout (KO) mice and analyzed them using several behavioral tests. No difference was found in the anxiety level, motor coordination, hippocampus-dependent learning and memory between the KO mice and their wild-type (WT) littermates. Electrophysiological recordings of multiple forms of synaptic plasticity in the Schaffer collateral pathway-CA1 neurons also showed normal responses in the KO hippocampal slices. Morphological analyses revealed that the CPEB4-lacking pyramidal neurons possessed slightly elongated dendritic spines. Unlike its related family members, CPEB1 and CPEB3, CPEB4 seems to be dispensable for hippocampus-dependent plasticity, learning and memory. PMID:24386439

  10. Offline Persistence of Memory-Related Cerebral Activity during Active Wakefulness

    PubMed Central

    Orban, Pierre; Balteau, Evelyne; Degueldre, Christian; Luxen, André; Laureys, Steven; Maquet, Pierre

    2006-01-01

    Much remains to be discovered about the fate of recent memories in the human brain. Several studies have reported the reactivation of learning-related cerebral activity during post-training sleep, suggesting that sleep plays a role in the offline processing and consolidation of memory. However, little is known about how new information is maintained and processed during post-training wakefulness before sleep, while the brain is actively engaged in other cognitive activities. We show, using functional magnetic resonance imaging, that brain activity elicited during a new learning episode modulates brain responses to an unrelated cognitive task, during the waking period following the end of training. This post-training activity evolves in learning-related cerebral structures, in which functional connections with other brain regions are gradually established or reinforced. It also correlates with behavioral performance. These processes follow a different time course for hippocampus-dependent and hippocampus-independent memories. Our experimental approach allowed the characterization of the offline evolution of the cerebral correlates of recent memories, without the confounding effect of concurrent practice of the learned material. Results indicate that the human brain has already extensively processed recent memories during the first hours of post-training wakefulness, even when simultaneously coping with unrelated cognitive demands. PMID:16602824

  11. Sex-Related Differences in the Effects of Sleep Habits on Verbal and Visuospatial Working Memory

    PubMed Central

    Nakagawa, Seishu; Takeuchi, Hikaru; Taki, Yasuyuki; Nouchi, Rui; Sekiguchi, Atsushi; Kotozaki, Yuka; Miyauchi, Carlos M.; Iizuka, Kunio; Yokoyama, Ryoichi; Shinada, Takamitsu; Yamamoto, Yuki; Hanawa, Sugiko; Araki, Tsuyoshi; Kunitoki, Keiko; Sassa, Yuko; Kawashima, Ryuta

    2016-01-01

    Poor sleep quality negatively affects memory performance, and working memory in particular. We investigated sleep habits related to sleep quality including sleep duration, daytime nap duration, nap frequency, and dream content recall frequency (DCRF). Declarative working memory can be subdivided into verbal working memory (VWM) and visuospatial working memory (VSWM). We hypothesized that sleep habits would have different effects on VWM and VSWM. To our knowledge, our study is the first to investigate differences between VWM and VSWM related to daytime nap duration, nap frequency, and DCRF. Furthermore, we tested the hypothesis that the effects of duration and frequency of daytime naps and DCRF on VWM and VSWM differed according to sex. We assessed 779 healthy right-handed individuals (434 males and 345 females; mean age: 20.7 ± 1.8 years) using a digit span forward and backward VWM task, a forward and backward VSWM task, and sleep habits scales. A correlation analysis was used to test the relationships between VWM capacity (VWMC) and VSWM capacity (VSWMC) scores and sleep duration, nap duration, nap frequency, and DCRF. Furthermore, multiple regression analyses were conducted to identify factors associated with VWMC and VSWMC scores and to identify sex-related differences. We found significant positive correlations between VSWMC and nap duration and DCRF, and between VWMC and sleep duration in all subjects. Furthermore, we found that working memory capacity (WMC) was positively correlated with nap duration in males and with sleep duration in females, and DCRF was positively correlated with VSWMC in females. Our finding of sex-related differences in the effects of sleep habits on WMC has not been reported previously. The associations between WMC and sleep habits differed according to sex because of differences in the underlying neural correlates of VWM and VSWM, and effectiveness of the sleep habits in males and females. PMID:27516751

  12. Activation of NO-cGMP Signaling Rescues Age-Related Memory Impairment in Crickets

    PubMed Central

    Matsumoto, Yukihisa; Matsumoto, Chihiro S.; Takahashi, Toshihumi; Mizunami, Makoto

    2016-01-01

    Age-related memory impairment (AMI) is a common feature and a debilitating phenotype of brain aging in many animals. However, the molecular mechanisms underlying AMI are still largely unknown. The cricket Gryllus bimaculatus is a useful experimental animal for studying age-related changes in learning and memory capability; because the cricket has relatively short life-cycle and a high capability of olfactory learning and memory. Moreover, the molecular mechanisms underlying memory formation in crickets have been examined in detail. In the present study, we trained male crickets of different ages by multiple-trial olfactory conditioning to determine whether AMI occurs in crickets. Crickets 3 weeks after the final molt (3-week-old crickets) exhibited levels of retention similar to those of 1-week-old crickets at 30 min or 2 h after training; however they showed significantly decreased levels of 1-day retention, indicating AMI in long-term memory (LTM) but not in anesthesia-resistant memory (ARM) in olfactory learning of crickets. Furthermore, 3-week-old crickets injected with a nitric oxide (NO) donor, a cyclic GMP (cGMP) analog or a cyclic AMP (cAMP) analog into the hemolymph before conditioning exhibited a normal level of LTM, the same level as that in 1-week-old crickets. The rescue effect by NO donor or cGMP analog injection was absent when the crickets were injected after the conditioning. For the first time, an NO donor and a cGMP analog were found to antagonize the age-related impairment of LTM formation, suggesting that deterioration of NO synthase (NOS) or molecules upstream of NOS activation is involved in brain-aging processes. PMID:27616985

  13. Sex-Related Differences in the Effects of Sleep Habits on Verbal and Visuospatial Working Memory.

    PubMed

    Nakagawa, Seishu; Takeuchi, Hikaru; Taki, Yasuyuki; Nouchi, Rui; Sekiguchi, Atsushi; Kotozaki, Yuka; Miyauchi, Carlos M; Iizuka, Kunio; Yokoyama, Ryoichi; Shinada, Takamitsu; Yamamoto, Yuki; Hanawa, Sugiko; Araki, Tsuyoshi; Kunitoki, Keiko; Sassa, Yuko; Kawashima, Ryuta

    2016-01-01

    Poor sleep quality negatively affects memory performance, and working memory in particular. We investigated sleep habits related to sleep quality including sleep duration, daytime nap duration, nap frequency, and dream content recall frequency (DCRF). Declarative working memory can be subdivided into verbal working memory (VWM) and visuospatial working memory (VSWM). We hypothesized that sleep habits would have different effects on VWM and VSWM. To our knowledge, our study is the first to investigate differences between VWM and VSWM related to daytime nap duration, nap frequency, and DCRF. Furthermore, we tested the hypothesis that the effects of duration and frequency of daytime naps and DCRF on VWM and VSWM differed according to sex. We assessed 779 healthy right-handed individuals (434 males and 345 females; mean age: 20.7 ± 1.8 years) using a digit span forward and backward VWM task, a forward and backward VSWM task, and sleep habits scales. A correlation analysis was used to test the relationships between VWM capacity (VWMC) and VSWM capacity (VSWMC) scores and sleep duration, nap duration, nap frequency, and DCRF. Furthermore, multiple regression analyses were conducted to identify factors associated with VWMC and VSWMC scores and to identify sex-related differences. We found significant positive correlations between VSWMC and nap duration and DCRF, and between VWMC and sleep duration in all subjects. Furthermore, we found that working memory capacity (WMC) was positively correlated with nap duration in males and with sleep duration in females, and DCRF was positively correlated with VSWMC in females. Our finding of sex-related differences in the effects of sleep habits on WMC has not been reported previously. The associations between WMC and sleep habits differed according to sex because of differences in the underlying neural correlates of VWM and VSWM, and effectiveness of the sleep habits in males and females. PMID:27516751

  14. Activation of NO-cGMP Signaling Rescues Age-Related Memory Impairment in Crickets.

    PubMed

    Matsumoto, Yukihisa; Matsumoto, Chihiro S; Takahashi, Toshihumi; Mizunami, Makoto

    2016-01-01

    Age-related memory impairment (AMI) is a common feature and a debilitating phenotype of brain aging in many animals. However, the molecular mechanisms underlying AMI are still largely unknown. The cricket Gryllus bimaculatus is a useful experimental animal for studying age-related changes in learning and memory capability; because the cricket has relatively short life-cycle and a high capability of olfactory learning and memory. Moreover, the molecular mechanisms underlying memory formation in crickets have been examined in detail. In the present study, we trained male crickets of different ages by multiple-trial olfactory conditioning to determine whether AMI occurs in crickets. Crickets 3 weeks after the final molt (3-week-old crickets) exhibited levels of retention similar to those of 1-week-old crickets at 30 min or 2 h after training; however they showed significantly decreased levels of 1-day retention, indicating AMI in long-term memory (LTM) but not in anesthesia-resistant memory (ARM) in olfactory learning of crickets. Furthermore, 3-week-old crickets injected with a nitric oxide (NO) donor, a cyclic GMP (cGMP) analog or a cyclic AMP (cAMP) analog into the hemolymph before conditioning exhibited a normal level of LTM, the same level as that in 1-week-old crickets. The rescue effect by NO donor or cGMP analog injection was absent when the crickets were injected after the conditioning. For the first time, an NO donor and a cGMP analog were found to antagonize the age-related impairment of LTM formation, suggesting that deterioration of NO synthase (NOS) or molecules upstream of NOS activation is involved in brain-aging processes. PMID:27616985

  15. The influence of music-elicited emotions and relative pitch on absolute pitch memory for familiar melodies.

    PubMed

    Jakubowski, Kelly; Müllensiefen, Daniel

    2013-01-01

    Levitin's findings that nonmusicians could produce from memory the absolute pitches of self-selected pop songs have been widely cited in the music psychology literature. These findings suggest that latent absolute pitch (AP) memory may be a more widespread trait within the population than traditional AP labelling ability. However, it has been left unclear what factors may facilitate absolute pitch retention for familiar pieces of music. The aim of the present paper was to investigate factors that may contribute to latent AP memory using Levitin's sung production paradigm for AP memory and comparing results to the outcomes of a pitch labelling task, a relative pitch memory test, measures of music-induced emotions, and various measures of participants' musical backgrounds. Our results suggest that relative pitch memory and the quality and degree of music-elicited emotions impact on latent AP memory. PMID:23758506

  16. Memory for Melody: Infants Use a Relative Pitch Code

    ERIC Educational Resources Information Center

    Plantinga, Judy; Trainor, Laurel J.

    2005-01-01

    Pitch perception is fundamental to melody in music and prosody in speech. Unlike many animals, the vast majority of human adults store melodic information primarily in terms of relative not absolute pitch, and readily recognize a melody whether rendered in a high or a low pitch range. We show that at 6 months infants are also primarily relative…

  17. The effects of imperatorin on anxiety and memory-related behavior in male Swiss mice.

    PubMed

    Budzynska, Barbara; Kruk-Slomka, Marta; Skalicka-Wozniak, Krystyna; Biala, Grazyna; Glowniak, Kazimierz

    2012-08-01

    The purpose of the reported experiments was to examine the effects of imperatorin [9-(3-methylbut-2-enyloxy)-7H-furo[3,2-g]chromen-7-one], a bioactive furanocoumarin isolated from the fruits of Angelica archangelica (Angelica officinalis) on anxiety and memory-related behaviors of mice. Male Swiss mice were tested for anxiety and cognition, in the elevated plus maze test (EPM), using two different procedures. In the present experiments, imperatorin was administered acutely (at the doses of 5, 10, 20, 30, and 50 mg/kg); injections were made 15, 30, and 60 min before test (anxiety); 30 min before the first trial (memory acquisition); or immediately after the first trial (memory consolidation), as well as subchronically, twice a day for 6 days. On the seventh day, the mice were injected once with imperatorin (10 and 20 mg/kg, i.p.) 30 min before the test (anxiety) and 30 min before the first trial (memory acquisition), or immediately after the first trial (memory consolidation). We observed that imperatorin when administered acutely and repeatedly, at the doses of 10 and 20 mg/kg, exerted an anxiolytic effect on mice tested 30 min after the injection measured in the EPM test. By contrast, no such effect was observed after the acute administration of imperatorin at the doses of 5, 30 and 50 mg/kg. Moreover, other observations carried out 15 and 60 min after a single injection of the drug did not reveal any effect of imperatorin on anxiety behavior in the EPM test. Furthermore, acute and repeated administration of imperatorin (10 and 20 mg/kg) improved different stages of memory processes (both acquisition and consolidation) in a modified EPM test (mEPM). The results of our research suggest imperatorin to be an interesting therapeutical option in disorders with high anxiety levels and memory impairment. PMID:22686497

  18. A case study of voltage-gated potassium channel antibody-related limbic encephalitis with PET/MRI findings

    PubMed Central

    Day, Brian K.; Eisenman, Lawrence; Black, Joseph; Maccotta, Luigi; Hogan, R. Edward

    2015-01-01

    Preclinical and clinical studies have demonstrated the significance of inflammation and autoantibodies in epilepsy, and the use of immunotherapies in certain situations has become an established practice. Temporal lobe epilepsy can follow paraneoplastic or nonparaneoplastic limbic encephalitis associated with antibodies directed against brain antigens. Here, we focus on a patient with worsening confusion and temporal lobe seizures despite treatment with antiepileptic medications. Serial brain MRIs did not conclusively reveal structural abnormalities, so the patient underwent brain PET/MRI to simultaneously evaluate brain structure and function, revealing bitemporal abnormalities. The patient was diagnosed with voltage-gated potassium channel antibody-related limbic encephalitis based on clinical presentation, imaging findings, and antibody testing. Treatment included the addition of a second antiepileptic agent and oral steroids. His seizures and cognitive deficits improved and stabilized. PMID:26106579

  19. The Role of Working Memory and Contextual Constraints in Children's Processing of Relative Clauses

    ERIC Educational Resources Information Center

    Wieghall, Anna R.; Altmann, Gerry T. M.

    2011-01-01

    An auditory sentence comprehension task investigated the extent to which the integration of contextual and structural cues was mediated by verbal memory span with 32 English-speaking six- to eight-year-old children. Spoken relative clause sentences were accompanied by visual context pictures which fully (depicting the actions described within the…

  20. Micro- and Macroreference Frames: Specifying the Relations between Spatial Categories in Memory

    ERIC Educational Resources Information Center

    Greenauer, Nathan; Waller, David

    2010-01-01

    A substantial amount of research has demonstrated the importance of reference frames in organizing memory of object locations in both small and large environments. However, to date, little research has examined how the object locations represented in one reference frame are specified relative to object locations represented in another. In a series…

  1. Respecting Relations: Memory Access and Antecedent Retrieval in Incremental Sentence Processing

    ERIC Educational Resources Information Center

    Kush, Dave W.

    2013-01-01

    This dissertation uses the processing of anaphoric relations to probe how linguistic information is encoded in and retrieved from memory during real-time sentence comprehension. More specifically, the dissertation attempts to resolve a tension between the demands of a linguistic processor implemented in a general-purpose cognitive architecture and…

  2. New Rule Use Drives the Relation between Working Memory Capacity and Raven's Advanced Progressive Matrices

    ERIC Educational Resources Information Center

    Wiley, Jennifer; Jarosz, Andrew F.; Cushen, Patrick J.; Colflesh, Gregory J. H.

    2011-01-01

    The correlation between individual differences in working memory capacity and performance on the Raven's Advanced Progressive Matrices (RAPM) is well documented yet poorly understood. The present work proposes a new explanation: that the need to use a new combination of rules on RAPM problems drives the relation between performance and working…

  3. The Relations between Number Property Strategies, Working Memory, and Multiplication in Elementary Students

    ERIC Educational Resources Information Center

    Liu, Ru-De; Ding, Yi; Gao, Bing-Cheng; Zhang, Dake

    2015-01-01

    This study aimed to examine the relations among property strategies, working memory, and multiplication tasks with 101 Chinese fourth-grade students. Two multiplication property strategies (associative and distributive) were compared with no strategy and demonstrated differentiated effects on students' accuracy and reaction time. Associative…

  4. Cognitive Association Formation in Episodic Memory: Evidence from Event-Related Potentials

    ERIC Educational Resources Information Center

    Kim, Alice S. N.; Vallesi, Antonino; Picton, Terence W.; Tulving, Endel

    2009-01-01

    The present study focused on the processes underlying cognitive association formation by investigating subsequent memory effects. Event-related potentials were recorded as participants studied pairs of words, presented one word at a time, for later recall. The findings showed that a frontal-positive late wave (LW), which occurred 1-1.6 s after the…

  5. Age-Related Differences in the Temporal Dynamics of Prospective Memory Retrieval: A Lifespan Approach

    ERIC Educational Resources Information Center

    Mattli, Florentina; Zollig, Jacqueline; West, Robert

    2011-01-01

    The efficiency of prospective memory (PM) typically increases from childhood to young adulthood and then decreases in later adulthood. The current study used event-related brain potentials (ERPs) to examine the development of the neural correlates of processes associated with the detection of a PM cue, switching from the ongoing activity to the…

  6. Trauma-Related Dissociation as a Factor Affecting Musicians' Memory for Music: Some Possible Solutions

    ERIC Educational Resources Information Center

    Swart, Inette; van Niekerk, Caroline; Hartman, Woltemade

    2010-01-01

    An investigation of the influence of trauma on musicians revealed concentration and memory problems as two of the most common symptoms hampering the performance of affected individuals. In many instances where the causes of these problems were related to trauma sequelae, these could clearly be linked to dissociative symptoms. The following…

  7. Event Memory and Suggestibility in Abused and Neglected Children: Trauma-Related Psychopathology and Cognitive Functioning

    ERIC Educational Resources Information Center

    Chae, Yoojin; Goodman, Gail S.; Eisen, Mitchell L.; Qin, Jianjian

    2011-01-01

    This study examined event memory and suggestibility in 3- to 16-year-olds involved in forensic investigations of child maltreatment. A total of 322 children were interviewed about a play activity with an unfamiliar adult. Comprehensive measures of individual differences in trauma-related psychopathology and cognitive functioning were administered.…

  8. Age-Related Changes in Duration Reproduction: Involvement of Working Memory Processes

    ERIC Educational Resources Information Center

    Baudouin, Alexia; Vanneste, Sandrine; Pouthas, Viviane; Isingrini, Michel

    2006-01-01

    The aim of the present research was to study age-related changes in duration reproduction by differentiating the working memory processes underlying this time estimation task. We compared performances of young and elderly adults in a duration reproduction task performed in simple and concurrent task conditions. Participants were also administered…

  9. Self-Regulatory Private Speech Relates to Children's Recall and Organization of Autobiographical Memories

    ERIC Educational Resources Information Center

    Al-Namlah, Abdulrahman S.; Meins, Elizabeth; Fernyhough, Charles

    2012-01-01

    We investigated relations between 4- and 7-year-olds' (N=58) autobiographical memory and their use of self-regulatory private speech in a non-mnemonic context (a cognitive planning task). Children's use of self-regulatory private speech during the planning task was associated with longer autobiographical narratives which included specific rather…

  10. Dexras1 a unique ras-GTPase interacts with NMDA receptor activity and provides a novel dissociation between anxiety, working memory and sensory gating.

    PubMed

    Carlson, G C; Lin, R E; Chen, Y; Brookshire, B R; White, R S; Lucki, I; Siegel, S J; Kim, S F

    2016-05-13

    Dexras1 is a novel GTPase that acts at a confluence of signaling mechanisms associated with psychiatric and neurological disease including NMDA receptors, NOS1AP and nNOS. Recent work has shown that Dexras1 mediates iron trafficking and NMDA-dependent neurodegeneration but a role for Dexras1 in normal brain function or psychiatric disease has not been studied. To test for such a role, mice with germline knockout (KO) of Dexras1 were assayed for behavioral abnormalities as well as changes in NMDA receptor subunit protein expression. Because Dexras1 is up-regulated during stress or by dexamethasone treatment, we included measures associated with emotion including anxiety and depression. Baseline anxiety-like measures (open field and zero maze) were not altered, nor were depression-like behavior (tail suspension). Measures of memory function yielded mixed results, with no changes in episodic memory (novel object recognition) but a significant decrement on working memory (T-maze). Alternatively, there was an increase in pre-pulse inhibition (PPI), without concomitant changes in either startle amplitude or locomotor activity. PPI data are consistent with the direction of change seen following exposure to dopamine D2 antagonists. An examination of NMDA subunit expression levels revealed an increased expression of the NR2A subunit, contrary to previous studies demonstrating down-regulation of the receptor following antipsychotic exposure (Schmitt et al., 2003) and up-regulation after exposure to isolation rearing (Turnock-Jones et al., 2009). These findings suggest a potential role for Dexras1 in modulating a selective subset of psychiatric symptoms, possibly via its interaction with NMDARs and/or other disease-related binding-partners. Furthermore, data suggest that modulating Dexras1 activity has contrasting effects on emotional, sensory and cognitive domains. PMID:26946266

  11. Relating Memory To Functional Performance In Normal Aging to Dementia Using Hierarchical Bayesian Cognitive Processing Models

    PubMed Central

    Shankle, William R.; Pooley, James P.; Steyvers, Mark; Hara, Junko; Mangrola, Tushar; Reisberg, Barry; Lee, Michael D.

    2012-01-01

    Determining how cognition affects functional abilities is important in Alzheimer’s disease and related disorders (ADRD). 280 patients (normal or ADRD) received a total of 1,514 assessments using the Functional Assessment Staging Test (FAST) procedure and the MCI Screen (MCIS). A hierarchical Bayesian cognitive processing (HBCP) model was created by embedding a signal detection theory (SDT) model of the MCIS delayed recognition memory task into a hierarchical Bayesian framework. The SDT model used latent parameters of discriminability (memory process) and response bias (executive function) to predict, simultaneously, recognition memory performance for each patient and each FAST severity group. The observed recognition memory data did not distinguish the six FAST severity stages, but the latent parameters completely separated them. The latent parameters were also used successfully to transform the ordinal FAST measure into a continuous measure reflecting the underlying continuum of functional severity. HBCP models applied to recognition memory data from clinical practice settings accurately translated a latent measure of cognition to a continuous measure of functional severity for both individuals and FAST groups. Such a translation links two levels of brain information processing, and may enable more accurate correlations with other levels, such as those characterized by biomarkers. PMID:22407225

  12. Longitudinal working memory development is related to structural maturation of frontal and parietal cortices.

    PubMed

    Tamnes, Christian K; Walhovd, Kristine B; Grydeland, Håkon; Holland, Dominic; Østby, Ylva; Dale, Anders M; Fjell, Anders M

    2013-10-01

    Parallels between patterns of brain maturation and cognitive development have been observed repeatedly, but studies directly testing the relationships between improvements in specific cognitive functions and structural changes in the brain are lacking. Working memory development extends throughout childhood and adolescence and likely plays a central role for cognitive development in multiple domains and in several neurodevelopmental disorders. Neuroimaging, lesion, and electrophysiological studies indicate that working memory emerges from coordinated interactions of a distributed neural network in which fronto-parietal cortical regions are critical. In the current study, verbal working memory function, as indexed by performance on the Keep Track task, and volumes of brain regions were assessed at two time points in 79 healthy children and adolescents in the age range of 8-22 years. Longitudinal change in cortical and subcortical volumes was quantified by the use of Quantitative Anatomical Regional Change. Improvement in working memory was related to cortical volume reduction in bilateral prefrontal and posterior parietal regions and in regions around the central sulci. Importantly, these relationships were not explained by differences in gender, age, or intelligence level or change in intellectual abilities. Furthermore, the relationships did not interact with age and were not significantly different in children, young adolescents, and old adolescents. The results provide the first direct evidence that structural maturation of a fronto-parietal cortical network supports working memory development. PMID:23767921

  13. Digital memory encoding in Chinese dyscalculia: An event-related potential study.

    PubMed

    Wang, Enguo; Qin, Shutao; Chang, MengYan; Zhu, Xiangru

    2014-10-22

    This study reports the neurophysiological and behavioral correlates of digital memory encoding features in Chinese individuals with and without dyscalculia. Eighteen children with dyscalculia (ages 11.5-13.5) and 18 matched controls were tested, and their event-related potentials (ERPs) were digitally recorded simultaneously with behavioral measures. The results showed that both groups had a significant Dm effect, and this effect was greater in the control group. In the 300-400-ms, 400-500-ms, and 600-700-ms processing stages, both groups showed significant differences of digital memory encoding in the frontal, central, and parietal regions. In the 500-600-ms period, the Dm effect in the control group was significantly greater than that in the dyscalculia group only in the parietal region. These results suggest that individuals with dyscalculia exhibit impaired digital memory encoding and deficits in psychological resource allocation. PMID:25462475

  14. Child maltreatment, trauma-related psychopathology, and eyewitness memory in children and adolescents.

    PubMed

    McWilliams, Kelly; Harris, Latonya S; Goodman, Gail S

    2014-01-01

    Two experiments were conducted to examine eyewitness memory in children and adolescents (9- to 15-years-old) with and without known histories of maltreatment (e.g., physical abuse, exposure to domestic violence). In Experiment 1, participants (N = 35) viewed a positive film clip depicting a congenial interaction between family members. In Experiment 2, participants (N = 31) watched a negative film clip in which a family argument was shown. Younger age and higher levels of trauma-related psychopathology significantly predicted commission errors to direct questions when the positive family interaction had been viewed, but not when the negative family interaction had been shown. Maltreatment history was not a significant unique predictor of memory performance for the positive or negative film clip. Implications for a scientific understanding of the effects of child maltreatment on memory are discussed. PMID:25537437

  15. Evidence of a visual-to-auditory cross-modal sensory gating phenomenon as reflected by the human P50 event-related brain potential modulation.

    PubMed

    Lebib, Riadh; Papo, David; de Bode, Stella; Baudonnière, Pierre Marie

    2003-05-01

    We investigated the existence of a cross-modal sensory gating reflected by the modulation of an early electrophysiological index, the P50 component. We analyzed event-related brain potentials elicited by audiovisual speech stimuli manipulated along two dimensions: congruency and discriminability. The results showed that the P50 was attenuated when visual and auditory speech information were redundant (i.e. congruent), in comparison with this same event-related potential component elicited with discrepant audiovisual dubbing. When hard to discriminate, however, bimodal incongruent speech stimuli elicited a similar pattern of P50 attenuation. We concluded to the existence of a visual-to-auditory cross-modal sensory gating phenomenon. These results corroborate previous findings revealing a very early audiovisual interaction during speech perception. Finally, we postulated that the sensory gating system included a cross-modal dimension. PMID:12697279

  16. Neurophysiological correlates of age-related changes in working memory capacity.

    PubMed

    Mattay, Venkata S; Fera, Francesco; Tessitore, Alessandro; Hariri, Ahmad R; Berman, Karen F; Das, Saumitra; Meyer-Lindenberg, Andreas; Goldberg, Terry E; Callicott, Joseph H; Weinberger, Daniel R

    2006-01-01

    Cognitive abilities such as working memory (WM) capacity decrease with age. To determine the neurophysiological correlates of age-related reduction in working memory capacity, we studied 10 young subjects (<35 years of age; mean age=29) and twelve older subjects (>55 years of age; mean age=59) with whole brain blood oxygenation-level dependent (BOLD) fMRI on a 1.5 T GE MR scanner using a SPIRAL FLASH pulse sequence (TE=24 ms, TR=56 ms, FA=60 degrees , voxel dimensions=3.75 mm(3)). Subjects performed a modified version of the "n" back working memory task at different levels of increasing working memory load (1-Back, 2-Back and 3-Back). Older subjects performed as well as the younger subjects at 1-Back (p=0.4), but performed worse than the younger subjects at 2-Back (p<0.01) and 3-Back (p=0.06). Older subjects had significantly longer reaction time (RT) than younger subjects (p<0.04) at all levels of task difficulty. Image analysis using SPM 99 revealed a similar distribution of cortical activity between younger and older subjects at all task levels. However, an analysis of variance revealed a significant group x task interaction in the prefrontal cortex bilaterally; within working memory capacity, as in 1-Back when the older subjects performed as well as the younger subjects, they showed greater prefrontal cortical (BA 9) activity bilaterally. At higher working memory loads, however, when they performed worse then the younger subjects, the older subjects showed relatively reduced activity in these prefrontal regions. These data suggest that, within capacity, compensatory mechanisms such as additional prefrontal cortical activity are called upon to maintain proficiency in task performance. As cognitive demand increases, however, they are pushed past a threshold beyond which physiological compensation cannot be made and, a decline in performance occurs. PMID:16213083

  17. Competitive Semantic Memory Retrieval: Temporal Dynamics Revealed by Event-Related Potentials

    PubMed Central

    Hellerstedt, Robin; Johansson, Mikael

    2016-01-01

    Memories compete for retrieval when they are related to a common retrieval cue. Previous research has shown that retrieval of a target memory may lead to subsequent retrieval-induced forgetting (RIF) of currently irrelevant competing memories. In the present study, we investigated the time course of competitive semantic retrieval and examined the neurocognitive mechanisms underlying RIF. We contrasted two theoretical accounts of RIF by examining a critical aspect of this memory phenomenon, namely the extent to which it depends on successful retrieval of the target memory. Participants first studied category-exemplar word-pairs (e.g. Fruit—Apple). Next, we recorded electrophysiological measures of brain activity while the participants performed a competitive semantic cued-recall task. In this task, the participants were provided with the studied categories but they were instructed to retrieve other unstudied exemplars (e.g. Fruit—Ma__?). We investigated the event-related potential (ERP) correlates of retrieval success by comparing ERPs from successful and failed retrieval trials. To isolate the ERP correlates of continuous retrieval attempts from the ERP correlates of retrieval success, we included an impossible retrieval condition, with incompletable word-stem cues (Drinks—Wy__) and compared it with a non-retrieval presentation baseline condition (Occupation—Dentist). The participants’ memory for all the studied exemplars was tested in the final phase of the experiment. Taken together, the behavioural results suggest that RIF is independent of target retrieval. Beyond investigating the mechanisms underlying RIF, the present study also elucidates the temporal dynamics of semantic cued-recall by isolating the ERP correlates of retrieval attempt and retrieval success. The ERP results revealed that retrieval attempt is reflected in a late posterior negativity, possibly indicating construction of candidates for completing the word-stem cue and retrieval

  18. Culture effects on adults' earliest childhood recollection and self-description: implications for the relation between memory and the self.

    PubMed

    Wang, Q

    2001-08-01

    American and Chinese college students (N = 256) reported their earliest childhood memory on a memory questionnaire and provided self-descriptions on a shortened 20 Statements Test (M. H. Kuhn & T. S. McPartland, 1954). The average age at earliest memory of Americans was almost 6 months earlier than that of Chinese. Americans reported lengthy, specific, self-focused, and emotionally elaborate memories; they also placed emphasis on individual attributes in describing themselves. Chinese provided brief accounts of childhood memories centering on collective activities, general routines, and emotionally neutral events; they also included a great number of social roles in their self-descriptions. Across the entire sample, individuals who described themselves in more self-focused and positive terms provided more specific and self-focused memories. Findings are discussed in light of the interactive relation between autobiographical memory and cultural self-construal. PMID:11519928

  19. Age influences the relation between subjective valence ratings and emotional word use during autobiographical memory retrieval.

    PubMed

    Ford, Jaclyn H; DiGirolamo, Marissa A; Kensinger, Elizabeth A

    2016-09-01

    Recent research reveals an age-related increase in positive autobiographical memory retrieval using a number of positivity measures, including valence ratings and positive word use. It is currently unclear whether the positivity shift in each of these measures co-occurs, or if age uniquely influences multiple components of autobiographical memory retrieval. The current study examined the correspondence between valence ratings and emotional word use in young and older adults' autobiographical memories. Positive word use in narratives was associated with valence ratings only in young adults' narratives. Older adults' narratives contained a consistent level of positive word use regardless of valence rating, suggesting that positive words and concepts may be chronically accessible to older adults during memory retrieval, regardless of subjective valence. Although a relation between negative word use in narratives and negative valence ratings was apparent in both young and older adults, it was stronger in older adults' narratives. These findings confirm that older adults do vary their word use in accordance with subjective valence, but they do so in a way that is different from young adults. The results also point to a potential dissociation between age-related changes in subjective valence and in positive word use. PMID:26274398

  20. Working memory is related to perceptual processing: A case from color perception

    PubMed Central

    Allen, Elizabeth C.; Beilock, Sian L.; Shevell, Steven K.

    2011-01-01

    We explored the relation between individual differences in working memory (WM) and color constancy, the phenomenon of color perception that allows us to perceive the color of an object as relatively stable under changes in illumination. Successive color constancy (measured by first viewing a colored surface under a particular illumination and later recalling it under a new illumination) was better for higher-WM individuals than for lower-WM individuals. Moreover, the magnitude of this WM difference depended on how much contextual information was available in the scene, which typically improves color constancy. By contrast, simple color memory, measured by viewing and recalling a colored surface under the same illumination, showed no significant relation to WM. This study reveals a relation between WM and a low-level perceptual process not previously thought to operate within the confines of attentional control, and provides a first account of the individual differences in color constancy known about for decades. PMID:21480748

  1. Developmental Links Between Children's Working Memory and their Social Relations with Teachers and Peers in the Early School Years.

    PubMed

    de Wilde, Amber; Koot, Hans M; van Lier, Pol A C

    2016-01-01

    This study assessed the developmental links between children's working memory development and their relations with teachers and peers across 2 years of kindergarten and early elementary school. Kindergarten and first grade children, N = 1109, 50% boys, were followed across 2 school-years. Children were assessed across 3 waves, in the fall and spring of the first school-year (within school-year), and finally in the spring of the second school-year. Working memory was assessed using a visuo-spatial working memory task. The developmental links between working memory and child-reported teacher-child relationship quality (warmth and conflict) and peer-nominated likeability and friendedness were assessed using autoregressive cross-lagged models. Lower working memory scores were related to increases in teacher-child conflict and decreases in teacher-child warmth one school-year later, in addition to decreases in likeability by peers within the same school-year. Conversely, teacher-child conflict was negatively associated with the development of working memory across the studied period. Path estimates between working memory and social relational factors were similar for boys and girls. Findings show developmental links between working memory and social-relational factors and vice versa. These results suggest that children's working memory development can be fostered through pro-social relations with teachers in early elementary school children. PMID:26219261

  2. Relations among Language Exposure, Phonological Memory, and Language Development in Spanish-English Bilingually Developing 2-Year-Olds

    ERIC Educational Resources Information Center

    Parra, Marisol; Hoff, Erika; Core, Cynthia

    2011-01-01

    The relation of phonological memory to language experience and development was investigated in 41 Spanish-English bilingual first language learners. The children's relative exposure to English and Spanish and their phonological memory for English- and Spanish-like nonwords were assessed at 22 months of age, and their productive vocabulary and…

  3. Altered Hippocampal Transcript Profile Accompanies an Age-Related Spatial Memory Deficit in Mice

    ERIC Educational Resources Information Center

    Verbitsky, Miguel; Yonan, Amanda L.; Malleret, Gael; Kandel, Eric R.; Gilliam, T. Conrad; Pavlidis, Paul

    2004-01-01

    We have carried out a global survey of age-related changes in mRNA levels in the 57BL/6NIA mouse hippocampus and found a difference in the hippocampal gene expression profile between 2-month-old young mice and 15-month-old middle-aged mice correlated with an age-related cognitive deficit in hippocampal-based explicit memory formation. Middle-aged…

  4. Controlled processes account for age-related decrease in episodic memory.

    PubMed

    Vanderaspoilden, Valérie; Adam, Stéphane; der Linden, Martial Van; Morais, José

    2007-05-01

    A decrease in controlled processes has been proposed to be responsible for age-related episodic memory decline. We used the Process Dissociation Procedure, a method that attempts to estimate the contribution of controlled and automatic processes to cognitive performance, and entered both estimates in regression analyses. Results indicate that only controlled processes explained a great part of the age-related variance in a word recall task, especially when little environmental support was offered. PMID:16860766

  5. Cyclic nucleotide–gated channels, calmodulin, adenylyl cyclase, and calcium/calmodulin-dependent protein kinase II are required for late, but not early, long-term memory formation in the honeybee

    PubMed Central

    Matsumoto, Yukihisa; Sandoz, Jean-Christophe; Devaud, Jean-Marc; Lormant, Flore; Mizunami, Makoto; Giurfa, Martin

    2014-01-01

    Memory is a dynamic process that allows encoding, storage, and retrieval of information acquired through individual experience. In the honeybee Apis mellifera, olfactory conditioning of the proboscis extension response (PER) has shown that besides short-term memory (STM) and mid-term memory (MTM), two phases of long-term memory (LTM) are formed upon multiple-trial conditioning: an early phase (e-LTM) which depends on translation from already available mRNA, and a late phase (l-LTM) which requires de novo transcription and translation. Here we combined olfactory PER conditioning and neuropharmacological inhibition and studied the involvement of the NO–cGMP pathway, and of specific molecules, such as cyclic nucleotide-gated channels (CNG), calmodulin (CaM), adenylyl cyclase (AC), and Ca2+/calmodulin-dependent protein kinase (CaMKII), in the formation of olfactory LTM in bees. We show that in addition to NO–cGMP and cAMP–PKA, CNG channels, CaM, AC, and CaMKII also participate in the formation of a l-LTM (72-h post-conditioning) that is specific for the learned odor. Importantly, the same molecules are dispensable for olfactory learning and for the formation of both MTM (in the minute and hour range) and e-LTM (24-h post-conditioning), thus suggesting that the signaling pathways leading to l-LTM or e-LTM involve different molecular actors. PMID:24741108

  6. Lateralized differences in tympanic membrane temperature, but not induced mood, are related to episodic memory.

    PubMed

    Propper, Ruth E; Barr, Taylor D; Brunyé, Tad T

    2015-03-01

    The present research examined the effects of pre-encoding and pre-recall induced mood on episodic memory. It was hypothesized that happy and/or angry mood prior to encoding (increasing left hemisphere activity), in tandem with fearful mood prior to recall (increasing right hemisphere activity) would be associated with superior episodic memory. It was also hypothesized that tympanic membrane measures (TMT), indicative of hemispheric activity, would change as a function of induced mood. Although subjectively-experienced mood induction was successful, pre-encoding and pre-recall mood did not alter memory, and only altered TMT in the pre-encoding fear and pre-recall angry mood induction conditions. Interestingly, baseline absolute difference between left and right TMT, a measure of differential hemispheric activity, regardless of the direction of that activity, was significantly positively related to number of total words written, number of correctly recalled words, and corrected recall score. This same TMT measure pre-encoding, regardless of specific mood, was significantly negatively related to false recall. Results are discussed in terms the HERA model of episodic memory, and in the nature of interhemispheric interaction involved in episodic recall. PMID:25647603

  7. Greater memory impairment in dementing females than males relative to sex-matched healthy controls.

    PubMed

    Gale, Shawn D; Baxter, Leslie; Thompson, Juliann

    2016-01-01

    Previously we demonstrated sex differences in episodic memory in healthy elderly and suggested that normative data be separated by sex. The present study extended the exploration of sex differences on memory measures into two clinical populations, mild cognitive impairment (MCI) and Alzheimer's disease (AD). Seventy-six subjects with MCI and 101 subjects with AD diagnosed by a multidisciplinary team were included. These two groups were also compared to a group of 177 healthy elderly control participants. Sex differences on the Rey Auditory Verbal Learning Test (RAVLT; total and delayed recall) raw scores and Brief Visuospatial Memory Test-Revised (BVMT-R) were demonstrated within the healthy but not the MCI or AD groups. Calculating z scores by sex for both dementing groups based on the healthy controls suggested a larger performance gap between healthy and dementing women than between healthy and dementing men. MCI females were on average 0.48 standard deviations lower for total verbal learning compared to healthy female controls than were MCI males when compared to healthy male controls. For verbal delayed recall the gap was even larger (SD = 1.09). Similarly, on the BVMT-R, a measure of visual memory, the difference was 0.60 standard deviations for total visual learning and 0.99 standard deviations for delayed recall. This same sex difference, with females showing greater impairment compared to the controls group than did the males, was also present within the AD group. The greater memory impairment in dementing females rather than males when compared to sex-matched healthy controls was unlikely to be due to more severe illness since females performed equivalently to males on the Clinical Dementia Rating Scale, Mini-Mental Status Examination, and Dementia Rating Scale, and were also similar for age, education, and apolipoprotein status. The present study suggested relatively greater memory impairment in females with MCI or AD than in controls. PMID:26735615

  8. A cognitive psychometric model for the psychodiagnostic assessment of memory-related deficits.

    PubMed

    Alexander, Gregory E; Satalich, Timothy A; Shankle, W Rodman; Batchelder, William H

    2016-03-01

    Clinical tests used for psychodiagnostic purposes, such as the well-known Alzheimer's Disease Assessment Scale: Cognitive subscale (ADAS-Cog), include a free-recall task. The free-recall task taps into latent cognitive processes associated with learning and memory components of human cognition, any of which might be impaired with the progression of Alzheimer's disease (AD). A Hidden Markov model of free recall is developed to measure latent cognitive processes used during the free-recall task. In return, these cognitive measurements give us insight into the degree to which normal cognitive functions are differentially impaired by medical conditions, such as AD and related disorders. The model is used to analyze the free-recall data obtained from healthy elderly participants, participants diagnosed as having mild cognitive impairment, and participants diagnosed with early AD. The model is specified hierarchically to handle item differences because of the serial position curve in free recall, as well as within-group individual differences in participants' recall abilities. Bayesian hierarchical inference is used to estimate the model. The model analysis suggests that the impaired patients have the following: (1) long-term memory encoding deficits, (2) short-term memory (STM) retrieval deficits for all but very short time intervals, (3) poorer transfer into long-term memory for items successfully retrieved from STM, and (4) poorer retention of items encoded into long-term memory after longer delays. Yet, impaired patients appear to have no deficit in immediate recall of encoded words in long-term memory or for very short time intervals in STM. PMID:26214016

  9. Memory performance is related to the cortisol awakening response in older people, but not to the diurnal cortisol slope.

    PubMed

    Hidalgo, Vanesa; Almela, Mercedes; Pulopulos, Matias M; Salvador, Alicia

    2016-09-01

    There are large individual differences in age-related cognitive decline. Hypothalamic-pituitary-adrenal axis (HPA-axis) functioning has been suggested as one of the mechanisms underlying these differences. This study aimed to investigate the relationships between the diurnal cortisol cycle, measured as the cortisol awakening response (CAR), and the diurnal cortisol slope (DCS) and the memory performance of healthy older people. To do so, we assessed the verbal, visual, and working memory performance of 64 participants (32 men) from 57 to 76 years old who also provided 14 saliva samples on two consecutive weekdays to determine their diurnal cortisol cycle. The CAR was linearly and negatively associated with verbal (significantly) and visual (marginally) memory domains, but not with working memory. Sex did not moderate these relationships. Furthermore, no associations were found between the DCS and any of the three memory domains assessed. Our results indicate that the two components of the diurnal cortisol cycle have different relationships with memory performance, with the CAR being more relevant than DCS in understanding the link from HPA-axis activity and regulation to different types of memory. These results suggest that the CAR is related to memory domains dependent on hippocampal functioning (i.e., declarative memory), but not to those that are more dependent on prefrontal cortex functioning (i.e., working memory). PMID:27266967

  10. Reduced hippocampal and amygdala activity predicts memory distortions for trauma reminders in combat-related PTSD.

    PubMed

    Hayes, Jasmeet Pannu; LaBar, Kevin S; McCarthy, Gregory; Selgrade, Elizabeth; Nasser, Jessica; Dolcos, Florin; Morey, Rajendra A

    2011-05-01

    Neurobiological models of posttraumatic stress disorder (PTSD) suggest that altered activity in the medial temporal lobes (MTL) during encoding of traumatic memories contribute to the development and maintenance of the disorder. However, there is little direct evidence in the PTSD literature to support these models. The goal of the present study was to examine MTL activity during trauma encoding in combat veterans using the subsequent memory paradigm. Fifteen combat veterans diagnosed with PTSD and 14 trauma-exposed control participants viewed trauma-related and neutral pictures while undergoing event-related fMRI. Participants returned one week after scanning for a recognition memory test. Region-of-interest (ROI) and voxel-wise whole brain analyses were conducted to examine the neural correlates of successful memory encoding. Patients with PTSD showed greater false alarm rates for novel lures than the trauma-exposed control group, suggesting reliance on gist-based representations in lieu of encoding contextual details. Imaging analyses revealed reduced activity in the amygdala and hippocampus in PTSD patients during successful encoding of trauma-related stimuli. Reduction in left hippocampal activity was associated with high arousal symptoms on the Clinician-Administered PTSD Scale (CAPS). The behavioral false alarm rate for traumatic stimuli co-varied with activity in the bilateral precuneus. These results support neurobiological theories positing reduced hippocampal activity under conditions of high stress and arousal. Reduction in MTL activity for successfully encoded stimuli and increased precuneus activity may underlie reduced stimulus-specific encoding and greater gist memory in patients with PTSD, leading to maintenance of the disorder. PMID:21047644

  11. Aging-associated formaldehyde-induced norepinephrine deficiency contributes to age-related memory decline.

    PubMed

    Mei, Yufei; Jiang, Chun; Wan, You; Lv, Jihui; Jia, Jianping; Wang, Xiaomin; Yang, Xu; Tong, Zhiqian

    2015-08-01

    A norepinephrine (NE) deficiency has been observed in aged rats and in patients with Alzheimer's disease and is thought to cause cognitive disorder. Which endogenous factor induces NE depletion, however, is largely unknown. In this study, we investigated the effects of aging-associated formaldehyde (FA) on the inactivation of NE in vitro and in vivo, and on memory behaviors in rodents. The results showed that age-related DNA demethylation led to hippocampal FA accumulation, and when this occurred, the hippocampal NE content was reduced in healthy male rats of different ages. Furthermore, biochemical analysis revealed that FA rapidly inactivated NE in vitro and that an intrahippocampal injection of FA markedly reduced hippocampal NE levels in healthy adult rats. Unexpectedly, an injection of FA (at a pathological level) or 6-hydroxydopamine (6-OHDA, a NE depletor) can mimic age-related NE deficiency, long-term potentiation (LTP) impairments, and spatial memory deficits in healthy adult rats. Conversely, an injection of NE reversed age-related deficits in both LTP and memory in aged rats. In agreement with the above results, the senescence-accelerated prone 8 (SAMP8) mice also exhibited a severe deficit in LTP and memory associated with a more severe NE deficiency and FA accumulation, when compared with the age-matched, senescence-resistant 1 (SAMR1) mice. Injection of resveratrol (a natural FA scavenger) or NE into SAMP8 mice reversed FA accumulation and NE deficiency and restored the magnitude of LTP and memory. Collectively, these findings suggest that accumulated FA is a critical endogenous factor for aging-associated NE depletion and cognitive decline. PMID:25866202

  12. Aging-associated formaldehyde-induced norepinephrine deficiency contributes to age-related memory decline

    PubMed Central

    Mei, Yufei; Jiang, Chun; Wan, You; Lv, Jihui; Jia, Jianping; Wang, Xiaomin; Yang, Xu; Tong, Zhiqian

    2015-01-01

    A norepinephrine (NE) deficiency has been observed in aged rats and in patients with Alzheimer’s disease and is thought to cause cognitive disorder. Which endogenous factor induces NE depletion, however, is largely unknown. In this study, we investigated the effects of aging-associated formaldehyde (FA) on the inactivation of NE in vitro and in vivo, and on memory behaviors in rodents. The results showed that age-related DNA demethylation led to hippocampal FA accumulation, and when this occurred, the hippocampal NE content was reduced in healthy male rats of different ages. Furthermore, biochemical analysis revealed that FA rapidly inactivated NE in vitro and that an intrahippocampal injection of FA markedly reduced hippocampal NE levels in healthy adult rats. Unexpectedly, an injection of FA (at a pathological level) or 6-hydroxydopamine (6-OHDA, a NE depletor) can mimic age-related NE deficiency, long-term potentiation (LTP) impairments, and spatial memory deficits in healthy adult rats. Conversely, an injection of NE reversed age-related deficits in both LTP and memory in aged rats. In agreement with the above results, the senescence-accelerated prone 8 (SAMP8) mice also exhibited a severe deficit in LTP and memory associated with a more severe NE deficiency and FA accumulation, when compared with the age-matched, senescence-resistant 1 (SAMR1) mice. Injection of resveratrol (a natural FA scavenger) or NE into SAMP8 mice reversed FA accumulation and NE deficiency and restored the magnitude of LTP and memory. Collectively, these findings suggest that accumulated FA is a critical endogenous factor for aging-associated NE depletion and cognitive decline. PMID:25866202

  13. Age-related slowing of memory retrieval: Contributions of perceptual speed and cerebral white matter integrity

    PubMed Central

    Bucur, Barbara; Madden, David J.; Spaniol, Julia; Provenzale, James M.; Cabeza, Roberto; White, Leonard E.; Huettel, Scott A.

    2007-01-01

    Previous research suggests that, in reaction time (RT) measures of episodic memory retrieval, the unique effects of adult age are relatively small compared to the effects aging shares with more elementary abilities such as perceptual speed. Little is known, however, regarding the mechanisms of perceptual speed. We used diffusion tensor imaging (DTI) to test the hypothesis that white matter integrity, as indexed by fractional anisotropy (FA), serves as one mechanism of perceptual slowing in episodic memory retrieval. Results indicated that declines in FA in the pericallosal frontal region and in the genu of the corpus callosum, but not in other regions, mediated the relationship between perceptual speed and episodic retrieval RT. This relation held, though to a different degree, for both hits and correct rejections. These findings suggest that white matter integrity in prefrontal regions is one mechanism underlying the relation between individual differences in perceptual speed and episodic retrieval. PMID:17383774

  14. CNS Voltage-gated Calcium Channel Gene Variation And Prolonged Recovery Following Sport-related Concussion

    PubMed Central

    McDevitt, Jane

    2016-01-01

    Objectives: To examine the association between concussion duration and two calcium channel, voltage-dependent, R type, alpha 1E subunit (CACNA1E) single nucleotide polymorphisms (i.e., rs35737760 and rs704326). A secondary purpose was to examine the association between CACNA1E single nucleotide polymorphisms (SNPs) and three acute concussion severity scores (i.e., vestibule-ocular reflex test, balance error scoring scale, and Immediate Post-Concussion Assessment and Cognitive Testing). Methods: Forty athletes with a diagnosed concussion from a hospital concussion program completed a standardized initial evaluation. Concussion injury characteristics, acute signs and symptoms followed by an objective screening (i.e., vestibular ocular assessments, balance error scoring system test, and Immediate Post-Concussion Assessment and Cognitive Testing exam) were assessed. Enrolled participants provided salivary samples for isolation of DNA. Two exon SNPs rs35737760 and rs704326 within CACNA1E were genotyped. Results: There was a significant difference found between acute balance deficits and prolonged recovery group (X2 = 5.66, p = 0.017). There was an association found between the dominant model GG genotype (X2 = 5.41, p = 0.027) within the rs704326 SNP and prolonged recovery group. Significant differences were identified for the rs704326 SNP within the dominant model GG genotype (p = 0.030) for VOR scores by recovery. A significant difference was found between the rs704326 SNP codominant model AA (p = 0.042) and visual memory. There was an association between acute balance deficits and prolonged recovery (X2 = 5.66, p = 0.017) for the rs35737760 SNP. No significant associations between concussion severity and genotype for rs35737760 SNP. Conclusion: Athletes carrying the CACNA1E rs704326 homozygous genotype GG are at a greater risk of a prolonged recovery. Athletes that reported balance deficits at the time of injury were more likely to have prolonged recovery. These

  15. Hearing Loss Is Negatively Related to Episodic and Semantic Long-Term Memory but Not to Short-Term Memory

    ERIC Educational Resources Information Center

    Ronnberg, Jerker; Danielsson, Henrik; Rudner, Mary; Arlinger, Stig; Sternang, Ola; Wahlin, Ake; Nilsson, Lars-Goran

    2011-01-01

    Purpose: To test the relationship between degree of hearing loss and different memory systems in hearing aid users. Method: Structural equation modeling (SEM) was used to study the relationship between auditory and visual acuity and different cognitive and memory functions in an age-hetereogenous subsample of 160 hearing aid users without…

  16. Stress enhances retrieval of drug-related memories in abstinent heroin addicts.

    PubMed

    Zhao, Li-Yan; Shi, Jie; Zhang, Xiao-Li; Epstein, David H; Zhang, Xiang-Yang; Liu, Yu; Kosten, Thomas R; Lu, Lin

    2010-02-01

    Stress is associated with relapse to drugs after abstinence, but the mechanisms for this association are unclear. One mechanism may be that stress enhances abstinent addicts' recall of memories of drugs as stress relievers. This study assessed the effects of stress on free recall and cued recall of 10 heroin-related and 10 neutral words learned 24 h earlier by 102 abstinent heroin addicts. These participants were randomly assigned to three experiments that also assessed attention and working memory. Experiment 1 used a psychosocial stressor (Trier social stress test (TSST)) before testing for recall of heroin-related words. Experiment 2 added administration of the beta-adrenoceptor antagonist propranolol 1 h before the psychosocial stressor. Experiment 3 added administration of either cortisol with propranolol, cortisol alone, or propranolol alone 1 h before word recall to determine whether stress enhancement of heroin-related word recall required noradrenergic-glucocorticoid interactions. We found that free recall of heroin-related words in abstinent addicts was enhanced after stress or cortisol administration when compared with a non-stress condition or placebo, respectively, whereas these interventions had no effect on neutral word recall. beta-adrenergic blockade blocked the enhancing effect of stress or cortisol on free recall of heroin-related words. Neither stress nor cortisol affected cued recall, attention, or working memory. The potential of beta-adrenergic blockade to reduce or block stress-induced enhancement of drug-related memory retrieval may be relevant to preventing stress-induced relapse in abstinent heroin addicts. PMID:19890257

  17. 20. DETAIL VIEW OF NONSUBMERSIBLE TAINTER GATE, SHOWING GATE, GATE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. DETAIL VIEW OF NONSUBMERSIBLE TAINTER GATE, SHOWING GATE, GATE ARM, TRUNNION PIN, PIER AND GATE GAUGE, LOOKING WEST - Upper Mississippi River 9-Foot Channel, Lock & Dam No. 10, Guttenberg, Clayton County, IA

  18. 17. DETAIL VIEW OF NONSUBMERSIBLE TAINTER GATE, SHOWING GATES, GATE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. DETAIL VIEW OF NON-SUBMERSIBLE TAINTER GATE, SHOWING GATES, GATE ARMS, PIERS AND DAM BRIDGE, WITH ROLLER GATE HEADHOUSE IN BACKGROUND, LOOKING SOUTHEAST - Upper Mississippi River 9-Foot Channel, Lock & Dam No. 9, Lynxville, Crawford County, WI

  19. 20. DETAIL VIEW OF SUBMERSIBLE GATE, SHOWING GATE ARMS, GATE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. DETAIL VIEW OF SUBMERSIBLE GATE, SHOWING GATE ARMS, GATE PIERS, TRUNNION PIN AND GATE GAUGE, LOOKING NORTHEAST - Upper Mississippi River 9-Foot Channel, Lock & Dam No. 8, On Mississippi River near Houston County, MN, Genoa, Vernon County, WI

  20. 21. DETAIL VIEW OF SUBMERSIBLE TAINTER GATE, SHOWING GATE, GATE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    21. DETAIL VIEW OF SUBMERSIBLE TAINTER GATE, SHOWING GATE, GATE ARM, TRUNNION PIN, PIER AND GATE GAUGE, LOOKING EAST - Upper Mississippi River 9-Foot Channel, Lock & Dam No. 10, Guttenberg, Clayton County, IA

  1. Intention to encode boosts memory-related pre-stimulus EEG beta power.

    PubMed

    Schneider, Signe Luisa; Rose, Michael

    2016-01-15

    Pre-stimulus oscillatory brain activity can predict the degree to which an upcoming stimulus will be remembered at a later point in time. Recently, increased pre-stimulus power in ongoing theta (5-8Hz) and low beta (13-17Hz) bands during encoding has been associated with enhanced memory performance. When a cue is presented before stimulus onset, encoding-related brain activations may be regarded as a sign of preparation for the upcoming stimulus. Here, we investigated whether the intention to encode the following stimulus into long-term memory affects these preparatory pre-stimulus activations during encoding. Two groups of 18 participants took part in a subsequent memory paradigm. Electroencephalogram (EEG) was recorded while participants were presented with a series of pictures, each one preceded by a cue, which were supposed to be classified according to animacy. One group was informed about the upcoming recognition task and therefore was enabled to develop the intention to encode the stimuli (intentional encoding), whereas the other group did not receive this information (incidental encoding). Afterwards, recognition of the pictures was tested. During intentional encoding only, power in theta and low beta bands was found to be significantly increased before the onset of pictures that were later remembered compared to later forgotten ones. Group comparisons confirmed greater memory-related power increases in the low beta band for intentional than incidental encoding. These findings indicate that oscillatory states that are associated with successful encoding can be initiated voluntarily if the intention to encode the stimuli is given. We therefore suggest low beta band activation before stimulus onset to be an indicator of memory-specific preparation for an upcoming stimulus. PMID:26584862

  2. A four-component model of age-related memory change.

    PubMed

    Healey, M Karl; Kahana, Michael J

    2016-01-01

    We develop a novel, computationally explicit, theory of age-related memory change within the framework of the context maintenance and retrieval (CMR2) model of memory search. We introduce a set of benchmark findings from the free recall and recognition tasks that include aspects of memory performance that show both age-related stability and decline. We test aging theories by lesioning the corresponding mechanisms in a model fit to younger adult free recall data. When effects are considered in isolation, many theories provide an adequate account, but when all effects are considered simultaneously, the existing theories fail. We develop a novel theory by fitting the full model (i.e., allowing all parameters to vary) to individual participants and comparing the distributions of parameter values for older and younger adults. This theory implicates 4 components: (a) the ability to sustain attention across an encoding episode, (b) the ability to retrieve contextual representations for use as retrieval cues, (c) the ability to monitor retrievals and reject intrusions, and (d) the level of noise in retrieval competitions. We extend CMR2 to simulate a recognition memory task using the same mechanisms the free recall model uses to reject intrusions. Without fitting any additional parameters, the 4-component theory that accounts for age differences in free recall predicts the magnitude of age differences in recognition memory accuracy. Confirming a prediction of the model, free recall intrusion rates correlate positively with recognition false alarm rates. Thus, we provide a 4-component theory of a complex pattern of age differences across 2 key laboratory tasks. PMID:26501233

  3. The significance of caudate volume for age-related associative memory decline.

    PubMed

    Bauer, E; Toepper, M; Gebhardt, H; Gallhofer, B; Sammer, G

    2015-10-01

    Aging comes along with reduced gray matter (GM) volume in several cerebral areas and with cognitive performance decline in different cognitive domains. Moreover, regional GM volume is linked to specific cognitive sub processes in older adults. However, it remains unclear which regional changes in older individuals are directly associated with decreased cognitive performance. Moreover, most of the studies on this topic focused on hippocampal and prefrontal brain regions and their relation to memory and executive functioning. Interestingly, there are only a few studies that reported an association between striatal brain volume and cognitive performance. This is insofar surprising that striatal structures are (1) highly affected by age and (2) involved in different neural circuits that serve intact cognition. To address these issues, voxel-based morphometry (VBM) was used to analyze GM volume in 18 younger and 18 older adults. Moreover, several neuropsychological tests from different neuropsychological test batteries were applied to assess a broad range of cognitive domains. Older adults showed less GM volume than younger adults within frontal, striatal, and cerebellar brain regions. In the group of older adults, significant correlations were found between striatal GM volume and memory performance and between prefrontal/temporal GM volume and executive functioning. The only direct overlap between brain regions associated with regional atrophy and cognitive performance in older adults was found for the right caudate: older adults showed reduced caudate volume relative to younger adults. Moreover, caudate volume was positively correlated with associative memory accuracy in older adults and older adults showed poorer performances than younger adults in the respective associative memory task. Taken together, the current findings indicate the relevance of the caudate for associative memory decline in the aging brain. PMID:26119913

  4. Aging and associative recognition: A view from the DRYAD model of age-related memory deficits.

    PubMed

    Benjamin, Aaron S

    2016-02-01

    How do we best characterize the memory deficits that accompany aging? A popular hypothesis, articulated originally by Naveh-Benjamin (2000) and reviewed in the accompanying article by Smyth and Naveh-Benjamin (2016), suggests that older adults are selectively deficient in establishing associations between to-be-learned memoranda and as a result have deficits in memory for sources or contexts. An alternative proposal, called density of representations yields age-related deficits (DRYAD) and outlined in recent articles by Benjamin (2010) and colleagues (Benjamin, Diaz, Matzen, & Johnson, 2012), attributes disproportionate deficits in memory to a global, rather than a selective, deficit of memory. In an attempt to adjudicate between these competing positions, Smyth and Naveh-Benjamin (2016) discussed 2 sets of experimental data that they claim speak against the global deficit model. Here I review some general principles of how the global-deficit view is applied to experimental paradigms and demonstrate that even a simplified form of DRYAD can comfortably accommodate the critical findings cited by Smyth and Naveh-Benjamin. I also evaluate aspects of their results that may be problematic for DRYAD and describe ways in which DRYAD's account of associative recognition can be falsified. I end with a discussion of the complementary strengths and weaknesses of the 2 approaches and consider ways in which the associative deficit hypothesis and DRYAD might work more profitably together than apart. PMID:26866587

  5. Semantic False Memories In The Form Of Derived Relational Intrusions Following Training

    PubMed Central

    Guinther, Paul M; Dougher, Michael J

    2010-01-01

    Contemporary behavior analytic research is making headway in characterizing memory phenomena that typically have been characterized by cognitive models, and the current study extends this development by producing “false memories” in the form of functional equivalence responding. A match-to-sample training procedure was administered in order to encourage participants to treat groups of unrelated English words as being interchangeable. Following training, participants were presented with a list of words from within one of the groups for a free recall test and a recognition test. Results showed that participants were more likely to falsely recall and recognize words that had been assigned to the same group as the list words during prior training, relative to words not assigned to the same group and relative to words that co-occurred with list words. These results indicate that semantic relatedness can be experimentally manipulated in order to produce specific false memories. PMID:21119849

  6. Gulliver meets Descartes: early modern concepts of age-related memory loss.

    PubMed

    Schäfer, Daniel

    2003-03-01

    Age-related memory loss was a marginal issue in medical discussions during early modern times and until well into the second half of the 17th century. There are many possible explanations: the lack of similar traditions in antiquity and in the Middle Ages, insufficient physiological and morphological knowledge of the brain, and the underlying conflict between idealistic and materialistic perspectives on the functions of the soul and the conditions of these in old age. After these boundaries had been pushed back by the influence of Cartesianism and Iatromechanism, the problem of age-related memory loss was increasingly regarded as a physical illness and began to receive more attention. This trend first occurred in medicine, before spreading to the literary world, where the novel "Gulliver's Travels" is one clear and famous example. PMID:12785108

  7. Acute social stress before the planning phase improves memory performance in a complex real life-related prospective memory task.

    PubMed

    Glienke, Katharina; Piefke, Martina

    2016-09-01

    Successful execution of intentions, but also the failure to recall are common phenomena in everyday life. The planning, retention, and realization of intentions are often framed as the scientific concept of prospective memory. The current study aimed to examine the influence of acute stress on key dimensions of complex "real life" prospective memory. To this end, we applied a prospective memory task that involved the planning, retention, and performance of intentions during a fictional holiday week. Forty healthy males participated in the study. Half of the subjects were stressed with the Socially Evaluated Cold Pressor Test (SECPT) before the planning of intentions, and the other half of the participants underwent a control procedure at the same time. Salivary cortisol was used to measure the effectiveness of the SECPT stress induction. Stressed participants did not differ from controls in planning accuracy. However, when we compared stressed participants with controls during prospective memory retrieval, we found statistically significant differences in PM across the performance phase. Participants treated with the SECPT procedure before the planning phase showed improved prospective memory retrieval over time, while performance of controls declined. Particularly, there was a significant difference between the stress and control group for the last two days of the holiday week. Interestingly, control participants showed significantly better performance for early than later learned items, which could be an indicator of a primacy effect. This differential effect of stress on performance was also found in time- and event-dependent prospective memory. Our results demonstrate for the first time, that acute stress induced before the planning phase may improve prospective memory over the time course of the performance phase in time- and event-dependent prospective memory. Our data thus indicate that prospective memory can be enhanced by acute stress. PMID:27370532

  8. Relationships between default-mode network connectivity, medial temporal lobe structure, and age-related memory deficits.

    PubMed

    Ward, Andrew M; Mormino, Elizabeth C; Huijbers, Willem; Schultz, Aaron P; Hedden, Trey; Sperling, Reisa A

    2015-01-01

    Advanced aging negatively impacts memory performance. Brain aging has been associated with shrinkage in medial temporal lobe structures essential for memory--including hippocampus and entorhinal cortex--and with deficits in default-mode network connectivity. Yet, whether and how these imaging markers are relevant to age-related memory deficits remains a topic of debate. Using a sample of 182 older (age 74.6 ± 6.2 years) and 66 young (age 22.2 ± 3.6 years) participants, this study examined relationships among memory performance, hippocampus volume, entorhinal cortex thickness, and default-mode network connectivity across aging. All imaging markers and memory were significantly different between young and older groups. Each imaging marker significantly mediated the relationship between age and memory performance and collectively accounted for most of the variance in age-related memory performance. Within older participants, default-mode connectivity and hippocampus volume were independently associated with memory. Structural equation modeling of cross-sectional data within older participants suggest that entorhinal thinning may occur before reduced default-mode connectivity and hippocampal volume loss, which in turn lead to deficits in memory performance. PMID:25113793

  9. No evidence of relation between working memory and perception of interrupted speech in young adults.

    PubMed

    Nagaraj, Naveen K; Knapp, Andrea N

    2015-08-01

    Understanding interrupted speech requires top-down linguistic and cognitive restoration mechanisms. To investigate the relation between working memory (WM) and perception of interrupted speech, 20 young adults were asked to recognize sentences interrupted at 2 Hz, 8 Hz, and a combination of 2 and 8 Hz. WM was measured using automated reading and operation span tasks. Interestingly, the results presented here revealed no statistical relation between any of the interrupted speech recognition scores and WM scores. This finding is in agreement with previous findings that suggest greater reliance on linguistic factors relative to cognitive factors during perception of interrupted speech. PMID:26328740

  10. Reactivation of Reward-Related Patterns from Single Past Episodes Supports Memory-Based Decision Making.

    PubMed

    Wimmer, G Elliott; Büchel, Christian

    2016-03-01

    Rewarding experiences exert a strong influence on later decision making. While decades of neuroscience research have shown how reinforcement gradually shapes preferences, decisions are often influenced by single past experiences. Surprisingly, relatively little is known about the influence of single learning episodes. Although recent work has proposed a role for episodes in decision making, it is largely unknown whether and how episodic experiences contribute to value-based decision making and how the values of single episodes are represented in the brain. In multiple behavioral experiments and an fMRI experiment, we tested whether and how rewarding episodes could support later decision making. Participants experienced episodes of high reward or low reward in conjunction with incidental, trial-unique neutral pictures. In a surprise test phase, we found that participants could indeed remember the associated level of reward, as evidenced by accurate source memory for value and preferences to re-engage with rewarded objects. Further, in a separate experiment, we found that high-reward objects shown as primes before a gambling task increased financial risk taking. Neurally, re-exposure to objects in the test phase led to significant reactivation of reward-related patterns. Importantly, individual variability in the strength of reactivation predicted value memory performance. Our results provide a novel demonstration that affect-related neural patterns are reactivated during later experience. Reactivation of value information represents a mechanism by which memory can guide decision making. PMID:26961943

  11. The Relation between the Working Memory Skills of Sign Language Interpreters and the Quality of Their Interpretations

    ERIC Educational Resources Information Center

    Van Dijk, Rick; Christoffels, Ingrid; Postma, Albert; Hermans, Daan

    2012-01-01

    In two experiments we investigated the relationship between the working memory skills of sign language interpreters and the quality of their interpretations. In Experiment 1, we found that scores on 3-back tasks with signs and words were not related to the quality of interpreted narratives. In Experiment 2, we found that memory span scores for…

  12. Simple and Complex Memory Spans and Their Relation to Fluid Abilities: Evidence from List-Length Effects

    ERIC Educational Resources Information Center

    Unsworth, Nash; Engle, Randall W.

    2006-01-01

    Complex (working memory) span tasks have generally shown larger and more consistent correlations with higher-order cognition than have simple (or short-term memory) span tasks. The relation between verbal complex and simple verbal span tasks to fluid abilities as a function of list-length was examined. The results suggest that the simple…

  13. Sex-Related Hemispheric Lateralization of Amygdala Function in Emotionally Influenced Memory: An fMRI Investigation

    ERIC Educational Resources Information Center

    Cahill, Larry; Uncapher, Melina; Kilpatrick, Lisa; Alkire, Mike T.; Turner, Jessica

    2004-01-01

    The amygdala appears necessary for enhanced long-term memory associated with emotionally arousing events. Recent brain imaging investigations support this view and indicate a sex-related hemispheric lateralization exists in the amygdala relationship to memory for emotional material. This study confirms and further explores this finding. Healthy…

  14. The Specificity of Autobiographical Memories in Early Adolescence: The Role of Mother-Child Communication and Attachment-Related Beliefs

    ERIC Educational Resources Information Center

    Bosmans, Guy; Dujardin, Adinda; Raes, Filip; Braet, Caroline

    2013-01-01

    Although autobiographical memory specificity is an important developmental feature fostering adaptation throughout life, little is known about factors related to interindividual differences in autobiographical memory specificity. The current study investigated associations with early adolescents' communication with mother about their…

  15. The Processing of Causal and Hierarchical Relations in Semantic Memory as Revealed by N400 and Frontal Negativity

    PubMed Central

    Lei, Yi; Li, Hong

    2015-01-01

    Most current studies investigating semantic memory have focused on associative (ring-emerald) or taxonomic relations (bird-sparrow). Little is known about the question of how causal relations (virus- epidemic) are stored and accessed in semantic memory. The goal of this study was to examine the processing of causally related, general associatively related and hierarchically related word pairs when participants were required to evaluate whether pairs of words were related in any way. The ERP data showed that the N400 amplitude (200-500ms) elicited by unrelated related words was more negative than all related words. Furthermore, the late frontal distributed negativity (500-700ms) elicited by causally related words was smaller than hierarchically related words, but not for general associated words. These results suggested the processing of causal relations and hierarchical relations in semantic memory recruited different degrees of cognitive resources, especially for role binding. PMID:26148338

  16. The Processing of Causal and Hierarchical Relations in Semantic Memory as Revealed by N400 and Frontal Negativity.

    PubMed

    Liang, Xiuling; Chen, Qingfei; Lei, Yi; Li, Hong

    2015-01-01

    Most current studies investigating semantic memory have focused on associative (ring-emerald) or taxonomic relations (bird-sparrow). Little is known about the question of how causal relations (virus-epidemic) are stored and accessed in semantic memory. The goal of this study was to examine the processing of causally related, general associatively related and hierarchically related word pairs when participants were required to evaluate whether pairs of words were related in any way. The ERP data showed that the N400 amplitude (200-500 ms) elicited by unrelated related words was more negative than all related words. Furthermore, the late frontal distributed negativity (500-700 ms) elicited by causally related words was smaller than hierarchically related words, but not for general associated words. These results suggested the processing of causal relations and hierarchical relations in semantic memory recruited different degrees of cognitive resources, especially for role binding. PMID:26148338

  17. DRYAD and ADH: Further comments on explaining age-related differences in memory.

    PubMed

    Naveh-Benjamin, Moshe; Smyth, Andrea C

    2016-02-01

    Recently, Smyth and Naveh-Benjamin (2016) questioned some of the main assumptions/hypotheses of DRYAD (or density of representations yields age-related deficits), a global-deficit model of aging and memory judgments (Benjamin, 2010; Benjamin et al., 2012). Smyth and Naveh-Benjamin (2016) provided empirical evidence that seems incompatible with DRYAD, but that fits the associative deficit hypothesis (ADH; Naveh-Benjamin, 2000), 1 specific-deficit theoretical view. In response, Aaron Benjamin (2016) offered a discussion of the complementary strengths and weaknesses of the DRYAD and the ADH, and the potential ways they might work together. We agree with many of his comments, but are not convinced that DRYAD is able to explain basic replicable empirical evidence of the type mentioned in Smyth and Naveh-Benjamin (2016). We discuss the reasons why we are not fully convinced by the demonstration of DRYAD's simulation of results presented in Benjamin (2016) and then present an implementation of ADH in a computationally based age-related impaired neuromodulation approach that was shown to simulate the basic empirical results of age-related associative memory deficits. We also discuss the issues of parsimony of theories and the appropriate type of representation, in the context of global versus specific deficits theoretical views. Finally, we show that the ADH's take on the distinction between items and associations has been adopted by some global computational models of memory. We believe that considerations of the above issues and others raised by Benjamin (2016) can lead to fruitful discussions that will benefit both theory development and existing knowledge of aging and memory. PMID:26866588

  18. Understanding age-related reductions in visual working memory capacity: Examining the stages of change detection

    PubMed Central

    Duda, Bryant; Hussey, Erin; Mason, Emily; Molitor, Robert J.; Woodman, Geoffrey F.; Ally, Brandon A.

    2014-01-01

    Visual working memory (VWM) capacity is reduced in older adults. Research has shown age-related impairments to VWM encoding, but aging is likely to affect multiple stages of VWM. In the present study, we recorded the event-related potentials (ERPs) of younger and older adults during VWM maintenance and retrieval. We measured encoding-stage processing with the P1 component, maintenance-stage processing with the contralateral delay activity (CDA), and retrieval-stage processing by comparing the activity for old and new items (old–new effect). Older adults showed lower behavioral capacity estimates (K) than did younger adults, but surprisingly, their P1 components and CDAs were comparable to those of younger adults. This remarkable dissociation between neural activity and behavior in the older adults indicated that the P1 and CDA did not accurately assess their VWM capacity. However, the neural activity evoked during VWM retrieval yielded results that helped clarify the age-related differences. During retrieval, younger adults showed early old–new effects in frontal and occipital areas and a late central–parietal old–new effect, whereas older adults showed a late right-lateralized parietal old–new effect. The younger adults’ early old–new effects strongly resembled an index of perceptual fluency, suggesting that perceptual implicit memory was activated. The activation of implicit memory could have facilitated the younger adults’ behavior, and the lack of these early effects in older adults may suggest that they have much lower-resolution memory than do younger adults. From these data, we speculated that younger and older adults store the same number of items in VWM, but that younger adults store a higher-resolution representation than do older adults. PMID:24420648

  19. How do verbal short-term memory and working memory relate to the acquisition of vocabulary and grammar? A comparison between first and second language learners.

    PubMed

    Verhagen, Josje; Leseman, Paul

    2016-01-01

    Previous studies show that verbal short-term memory (VSTM) is related to vocabulary learning, whereas verbal working memory (VWM) is related to grammar learning in children learning a second language (L2) in the classroom. In this study, we investigated whether the same relationships apply to children learning an L2 in a naturalistic setting and to monolingual children. We also investigated whether relationships with verbal memory differ depending on the type of grammar skill investigated (i.e., morphology vs. syntax). Participants were 63 Turkish children who learned Dutch as an L2 and 45 Dutch monolingual children (mean age = 5 years). Children completed a series of VSTM and VWM tasks, a Dutch vocabulary task, and a Dutch grammar task. A confirmatory factor analysis showed that VSTM and VWM represented two separate latent factors in both groups. Structural equation modeling showed that VSTM, treated as a latent factor, significantly predicted vocabulary and grammar. VWM, treated as a latent factor, predicted only grammar. Both memory factors were significantly related to the acquisition of morphology and syntax. There were no differences between the two groups. These results show that (a) VSTM and VWM are differentially associated with language learning and (b) the same memory mechanisms are employed for learning vocabulary and grammar in L1 children and in L2 children who learn their L2 naturalistically. PMID:26340756

  20. Cognitive and neuropsychological underpinnings of relational and conjunctive working memory binding across age.

    PubMed

    van Geldorp, Bonnie; Parra, Mario A; Kessels, Roy P C

    2015-01-01

    The ability to form associations (i.e., binding) is critical for memory formation. Recent studies suggest that aging specifically affects relational binding (associating separate features) but not conjunctive binding (integrating features within an object). Possibly, this dissociation may be driven by the spatial nature of the studies so far. Alternatively, relational binding may simply require more attentional resources. We assessed relational and conjunctive binding in three age groups and we included an interfering task (i.e., an articulatory suppression task). Binding was examined in a working memory (WM) task using non-spatial features: shape and colour. Thirty-one young adults (mean age = 22.35), 30 middle-aged adults (mean age = 54.80) and 30 older adults (mean age = 70.27) performed the task. Results show an effect of type of binding and an effect of age but no interaction between type of binding and age. The interaction between type of binding and interference was significant. These results indicate that aging affects relational binding and conjunctive binding similarly. However, relational binding is more susceptible to interference than conjunctive binding, which suggests that relational binding may require more attentional resources. We suggest that a general decline in WM resources associated with frontal dysfunction underlies age-related deficits in WM binding. PMID:25216357

  1. Gender differences in memory processing of female facial attractiveness: evidence from event-related potentials.

    PubMed

    Zhang, Yan; Wei, Bin; Zhao, Peiqiong; Zheng, Minxiao; Zhang, Lili

    2016-06-01

    High rates of agreement in the judgment of facial attractiveness suggest universal principles of beauty. This study investigated gender differences in recognition memory processing of female facial attractiveness. Thirty-four Chinese heterosexual participants (17 females, 17 males) aged 18-24 years (mean age 21.63 ± 1.51 years) participated in the experiment which used event-related potentials (ERPs) based on a study-test paradigm. The behavioral data results showed that both men and women had significantly higher accuracy rates for attractive faces than for unattractive faces, but men reacted faster to unattractive faces. Gender differences on ERPs showed that attractive faces elicited larger early components such as P1, N170, and P2 in men than in women. The results indicated that the effects of recognition bias during memory processing modulated by female facial attractiveness are greater for men than women. Behavioral and ERP evidences indicate that men and women differ in their attentional adhesion to attractive female faces; different mating-related motives may guide the selective processing of attractive men and women. These findings establish a contribution of gender differences on female facial attractiveness during memory processing from an evolutionary perspective. PMID:26928269

  2. Changes in pattern completion – a key mechanism to explain age-related recognition memory deficits?

    PubMed Central

    Vieweg, Paula; Stangl, Matthias; Howard, Lorelei R.; Wolbers, Thomas

    2016-01-01

    Accurate memory retrieval from partial or degraded input requires the reactivation of memory traces, a hippocampal mechanism termed pattern completion. Age-related changes in hippocampal integrity have been hypothesized to shift the balance of memory processes in favor of the retrieval of already stored information (pattern completion), to the detriment of encoding new events (pattern separation). Using a novel behavioral paradigm, we investigated the impact of cognitive aging (1) on recognition performance across different levels of stimulus completeness, and (2) on potential response biases. Participants were required to identify previously learned scenes among new ones. Additionally, all stimuli were presented in gradually masked versions to alter stimulus completeness. Both young and older adults performed increasingly poorly as the scenes became less complete, and this decline in performance was more pronounced in elderly participants indicative of a pattern completion deficit. Intriguingly, when novel scenes were shown, only the older adults showed an increased tendency to identify these as familiar scenes. In line with theoretical models, we argue that this reflects an age-related bias towards pattern completion. PMID:25597525

  3. Moringa oleifera mitigates memory impairment and neurodegeneration in animal model of age-related dementia.

    PubMed

    Sutalangka, Chatchada; Wattanathorn, Jintanaporn; Muchimapura, Supaporn; Thukham-mee, Wipawee

    2013-01-01

    To date, the preventive strategy against dementia is still essential due to the rapid growth of its prevalence and the limited therapeutic efficacy. Based on the crucial role of oxidative stress in age-related dementia and the antioxidant and nootropic activities of Moringa oleifera, the enhancement of spatial memory and neuroprotection of M. oleifera leaves extract in animal model of age-related dementia was determined. The possible underlying mechanism was also investigated. Male Wistar rats, weighing 180-220 g, were orally given M. oleifera leaves extract at doses of 100, 200, and 400 mg/kg at a period of 7 days before and 7 days after the intracerebroventricular administration of AF64A bilaterally. Then, they were assessed memory, neuron density, MDA level, and the activities of SOD, CAT, GSH-Px, and AChE in hippocampus. The results showed that the extract improved spatial memory and neurodegeneration in CA1, CA2, CA3, and dentate gyrus of hippocampus together with the decreased MDA level and AChE activity but increased SOD and CAT activities. Therefore, our data suggest that M. oleifera leaves extract is the potential cognitive enhancer and neuroprotectant. The possible mechanism might occur partly via the decreased oxidative stress and the enhanced cholinergic function. However, further explorations concerning active ingredient(s) are still required. PMID:24454988

  4. Moringa oleifera Mitigates Memory Impairment and Neurodegeneration in Animal Model of Age-Related Dementia

    PubMed Central

    Sutalangka, Chatchada; Wattanathorn, Jintanaporn; Muchimapura, Supaporn; Thukham-mee, Wipawee

    2013-01-01

    To date, the preventive strategy against dementia is still essential due to the rapid growth of its prevalence and the limited therapeutic efficacy. Based on the crucial role of oxidative stress in age-related dementia and the antioxidant and nootropic activities of Moringa oleifera, the enhancement of spatial memory and neuroprotection of M. oleifera leaves extract in animal model of age-related dementia was determined. The possible underlying mechanism was also investigated. Male Wistar rats, weighing 180–220 g, were orally given M. oleifera leaves extract at doses of 100, 200, and 400 mg/kg at a period of 7 days before and 7 days after the intracerebroventricular administration of AF64A bilaterally. Then, they were assessed memory, neuron density, MDA level, and the activities of SOD, CAT, GSH-Px, and AChE in hippocampus. The results showed that the extract improved spatial memory and neurodegeneration in CA1, CA2, CA3, and dentate gyrus of hippocampus together with the decreased MDA level and AChE activity but increased SOD and CAT activities. Therefore, our data suggest that M. oleifera leaves extract is the potential cognitive enhancer and neuroprotectant. The possible mechanism might occur partly via the decreased oxidative stress and the enhanced cholinergic function. However, further explorations concerning active ingredient(s) are still required. PMID:24454988

  5. Electromagnetic emission memory phenomena related to LiF ionic crystal deformation

    NASA Astrophysics Data System (ADS)

    Mavromatou, C.; Tombras, G. S.; Ninos, D.; Hadjicontis, V.

    2008-04-01

    During the uniaxial compression of LiF ionic monocrystals, acoustic and electromagnetic emissions (EME) are detected. We observed that when the compression is performed in successive loading, unloading cycles and these emissions are being monitored, no new emissions will occur unless the maximum stress of the previous cycle is exceeded, meaning that the material presents memory characteristics. This is observed not only for the acoustic emission (AE), which is the well known Kaiser effect, but for the EME as well. In other words, the material appears to memorize and reveal the previously maximum stress it suffered while being deformed. The importance of an electromagnetic memory feature of a material can be related to various applications in material science, especially when the detection of AE is not feasible or gives false alert. Such cases may very well be earthquakes' predictive indications, monitoring of mines' stability, imminent landslides, etc.

  6. Persistent neural activity in auditory cortex is related to auditory working memory in humans and nonhuman primates.

    PubMed

    Huang, Ying; Matysiak, Artur; Heil, Peter; König, Reinhard; Brosch, Michael

    2016-01-01

    Working memory is the cognitive capacity of short-term storage of information for goal-directed behaviors. Where and how this capacity is implemented in the brain are unresolved questions. We show that auditory cortex stores information by persistent changes of neural activity. We separated activity related to working memory from activity related to other mental processes by having humans and monkeys perform different tasks with varying working memory demands on the same sound sequences. Working memory was reflected in the spiking activity of individual neurons in auditory cortex and in the activity of neuronal populations, that is, in local field potentials and magnetic fields. Our results provide direct support for the idea that temporary storage of information recruits the same brain areas that also process the information. Because similar activity was observed in the two species, the cellular bases of some auditory working memory processes in humans can be studied in monkeys. PMID:27438411

  7. Developmental differences in relations between parent-reported executive function and unitized and non-unitized memory representations during childhood

    PubMed Central

    Blankenship, Sarah L.; Riggins, Tracy

    2015-01-01

    Previous research has documented an association between executive functioning (EF) and memory for bound details. However, it is unknown if this relation varies as a function of the type of bound information (i.e., unitized versus non-unitized) and whether this association changes as a function of age during childhood, when both EF and memory undergo rapid development. The current study sought to address these gaps by examining whether relations between parent-reported EF differed for unitized versus non-unitized memory representations and if these relations differed between children who were 4, 6, or 8 years of age. Results revealed that EF was selectively associated with non-unitized associative memory in 8-year-old children; no significant relations between EF and either memory condition were evident in 4- or 6-year-olds. These results suggest relations between EF and memory may be specific to non-unitized representations and that this association may emerge across childhood as both EF and memory abilities develop. PMID:26347683

  8. How do working-memory-related demand, reasoning ability and aversive reinforcement modulate conflict monitoring?

    PubMed Central

    Leue, Anja; Weber, Bernd; Beauducel, André

    2014-01-01

    Conflict monitoring is a process of stimulus evaluation and a pre-requisite for subsequent recruitment of cognitive control and behavioral adaptations. This study investigated how experimentally manipulated working-memory-related cognitive demand and aversive reinforcement modulate individual differences of conflict monitoring intensity and behavioral adjustments. Individual differences were assessed by means of an anxiety-related trait dimension (trait-BIS) and by means of reasoning abilities—a core determinant of intelligence. Moreover, we investigated the special role of verbal reasoning ability and figural reasoning ability for the modulation of the conflict monitoring intensity. Ninety participants performed a go/nogo task with four conditions each comprising a combination of low vs. high working-memory-related cognitive demand and low vs. high aversive reinforcement. No effect of aversive reinforcement was observed for the N2 amplitude. The fronto-central nogo N2 amplitude was more pronounced for high demand vs. low demand suggesting that cognitive demand served as an aversive costly event. Higher total reasoning abilities were associated with more intense conflict monitoring and shorter response times with increasing aversive reinforcement (defined as verbal error-feedback vs. monetary loss). Individuals with higher trait-BIS scores demonstrated a more intense conflict monitoring even in conditions with low aversive reinforcement and also a more cautious responding (i.e., response times slowing) with increasing aversive reinforcement indicating a focus on negative feedback prevention. The findings provide evidence for the conflict monitoring theory and suggest that working-memory-related demand overrules the impact of aversive reinforcement on conflict monitoring intensity. Reasoning abilities and anxiety-related traits go along with an intensification of conflict monitoring but differences in the flexibility of behavioral adjustment. PMID:24782739

  9. Retention and Switching Kinetics of Protonated Gate Field Effect Transistors

    SciTech Connect

    DEVINE,R.A.B.; HERRERA,GILBERT V.

    2000-06-27

    The switching and memory retention time has been measured in 50 {micro}m gatelength pseudo-non-volatile memory MOSFETs containing, protonated 40 nm gate oxides. Times of the order of 3.3 seconds are observed for fields of 3 MV cm{sup {minus}1}. The retention time with protons placed either at the gate oxide/substrate or gate oxide/gate electrode interfaces is found to better than 96% after 5,000 seconds. Measurement of the time dependence of the source-drain current during switching provides clear evidence for the presence of dispersive proton transport through the gate oxide.

  10. Retention and switching kinetics of protonated gate field effect transistors

    SciTech Connect

    DEVINE,R.A.B.; HERRERA,GILBERT V.

    2000-05-23

    The switching and memory retention time has been measured in 50 {micro}m gatelength pseudo-non-volatile memory MOSFETS containing, protonated 40 nm gate oxides. Times of the order of 3.3 seconds are observed for fields of 3 MV cm{sup {minus}1}. The retention time with protons placed either at the gate oxide/substrate or gate oxide/gate electrode interfaces is found to better than 96{percent} after 5,000 seconds. Measurement of the time dependence of the source-drain current during switching provides clear evidence for the presence of dispersive proton transport through the gate oxide.

  11. Investigation of field induced trapping on floating gates

    NASA Technical Reports Server (NTRS)

    Gosney, W. M.

    1975-01-01

    The development of a technology for building electrically alterable read only memories (EAROMs) or reprogrammable read only memories (RPROMs) using a single level metal gate p channel MOS process with all conventional processing steps is outlined. Nonvolatile storage of data is achieved by the use of charged floating gate electrodes. The floating gates are charged by avalanche injection of hot electrodes through gate oxide, and discharged by avalanche injection of hot holes through gate oxide. Three extra diffusion and patterning steps are all that is required to convert a standard p channel MOS process into a nonvolatile memory process. For identification, this nonvolatile memory technology was given the descriptive acronym DIFMOS which stands for Dual Injector, Floating gate MOS.

  12. Feature integration in visual working memory: parietal gamma activity is related to cognitive coordination.

    PubMed

    Morgan, Helen M; Muthukumaraswamy, Suresh D; Hibbs, Carina S; Shapiro, Kimron L; Bracewell, R Martyn; Singh, Krish D; Linden, David E J

    2011-12-01

    The mechanism by which distinct subprocesses in the brain are coordinated is a central conundrum of systems neuroscience. The parietal lobe is thought to play a key role in visual feature integration, and oscillatory activity in the gamma frequency range has been associated with perception of coherent objects and other tasks requiring neural coordination. Here, we examined the neural correlates of integrating mental representations in working memory and hypothesized that parietal gamma activity would be related to the success of cognitive coordination. Working memory is a classic example of a cognitive operation that requires the coordinated processing of different types of information and the contribution of multiple cognitive domains. Using magnetoencephalography (MEG), we report parietal activity in the high gamma (80-100 Hz) range during manipulation of visual and spatial information (colors and angles) in working memory. This parietal gamma activity was significantly higher during manipulation of visual-spatial conjunctions compared with single features. Furthermore, gamma activity correlated with successful performance during the conjunction task but not during the component tasks. Cortical gamma activity in parietal cortex may therefore play a role in cognitive coordination. PMID:21940605

  13. The effects of direction similarity in visual working memory: Behavioural and event-related potential studies.

    PubMed

    Zhang, Qian; Li, Shouxin; Wang, Xiusong; Che, Xiaowei

    2016-01-01

    Object similarity can improve visual working memory (VWM) performance in the change-detection task, but impair the recognition performance when it occurs at retrieval of VWM in the recognition task. The effect of direction similarity is an issue that has not been well resolved. Furthermore, electrophysiological evidence in support of the mechanisms that underlie the effects of similarity is still scarce. In the current study, we conducted three behavioural experiments to examine the effects of direction similarity on memory performance with regard to both the encoding and retrieval phases of VWM and one event-related potential (ERP) experiment to explore the neural signatures of direction similarity in VWM. Our behavioural studies indicated that direction similarity improved performance when it occurred at the encoding phase but impaired performance when it occurred at the retrieval phase. Moreover, the ERP experiment showed that the amplitude of the contralateral delay activity (CDA) increased with the increasing set size for similar but not dissimilar directions. In addition, the CDA amplitude for similar directions was lower than that for dissimilar directions at set size 2. Taken together, these findings suggest that direction similarity at encoding has a positive effect on VWM performance and at retrieval has a negative effect. Given that VWM capacity depends on information load and the number of objects, the positive effect of similarity may be attributed to reduced information load of memory objects. PMID:26443895

  14. The Memory That's Right and the Memory That's Left: Event-Related Potentials Reveal Hemispheric Asymmetries in the Encoding and Retention of Verbal Information

    ERIC Educational Resources Information Center

    Evans, Karen M.; Federmeier, Kara D.

    2007-01-01

    We examined the nature and timecourse of hemispheric asymmetries in verbal memory by recording event-related potentials (ERPs) in a continuous recognition task. Participants made overt recognition judgments to test words presented in central vision that were either novel (new words) or had been previously presented in the left or right visual…

  15. Sleep Deprivation Accelerates Delay-Related Loss of Visual Short-Term Memories Without Affecting Precision

    PubMed Central

    Wee, Natalie; Asplund, Christopher L.; Chee, Michael W. L.

    2013-01-01

    Study Objectives: Visual short-term memory (VSTM) is an important measure of information processing capacity and supports many higher-order cognitive processes. We examined how sleep deprivation (SD) and maintenance duration interact to influence the number and precision of items in VSTM using an experimental design that limits the contribution of lapses at encoding. Design: For each trial, participants attempted to maintain the location and color of three stimuli over a delay. After a retention interval of either 1 or 10 seconds, participants reported the color of the item at the cued location by selecting it on a color wheel. The probability of reporting the probed item, the precision of report, and the probability of reporting a nonprobed item were determined using a mixture-modeling analysis. Participants were studied twice in counterbalanced order, once after a night of normal sleep and once following a night of sleep deprivation. Setting: Sleep laboratory. Participants: Nineteen healthy college age volunteers (seven females) with regular sleep patterns. Interventions: Approximately 24 hours of total SD. Measurements and Results: SD selectively reduced the number of integrated representations that can be retrieved after a delay, while leaving the precision of object information in the stored representations intact. Delay interacted with SD to lower the rate of successful recall. Conclusions: Visual short-term memory is compromised during sleep deprivation, an effect compounded by delay. However, when memories are retrieved, they tend to be intact. Citation: Wee N; Asplund CL; Chee MWL. Sleep deprivation accelerates delay-related loss of visual short-term memories without affecting precision. SLEEP 2013;36(6):849-856. PMID:23729928

  16. Illusions and Delusions: Relating Experimentally-Induced False Memories to Anomalous Experiences and Ideas

    PubMed Central

    Corlett, Philip R.; Simons, Jon S.; Pigott, Jennifer S.; Gardner, Jennifer M.; Murray, Graham K.; Krystal, John H.; Fletcher, Paul C.

    2009-01-01

    The salience hypothesis of psychosis rests on a simple but profound observation that subtle alterations in the way that we perceive and experience stimuli have important consequences for how important these stimuli become for us, how much they draw our attention, how they embed themselves in our memory and, ultimately, how they shape our beliefs. We put forward the idea that a classical memory illusion – the Deese–Roediger–McDermott (DRM) effect – offers a useful way of exploring processes related to such aberrant belief formation. The illusion occurs when, as a consequence of its relationship to previous stimuli, a stimulus that has not previously been presented is falsely remembered. Such illusory familiarity is thought to be generated by the surprising fluency with which the stimulus is processed. In this respect, the illusion relates directly to the salience hypothesis and may share common cognitive underpinnings with aberrations of perception and attribution that are found in psychosis. In this paper, we explore the theoretical importance of this experimentally-induced illusion in relation to the salience model of psychosis. We present data showing that, in healthy volunteers, the illusion relates directly to self reported anomalies of experience and magical thinking. We discuss this finding in terms of the salience hypothesis and of a broader Bayesian framework of perception and cognition which emphasizes the salience both of predictable and unpredictable experiences. PMID:19956402

  17. Event-related brain potential correlates of prospective memory in symptomatically remitted male patients with schizophrenia

    PubMed Central

    Chen, Guoliang; Zhang, Lei; Ding, Weiyan; Zhou, Renlai; Xu, Peng; Lu, Shan; Sun, Li; Jiang, Zhongdong; Li, Huiju; Li, Yansong; Cui, Hong

    2015-01-01

    Prospective memory (PM) refers to the ability to remember to perform intended actions in the future. Although PM deficits are a prominent impairment in schizophrenia, little is still known about the nature of PM in symptomatically remitted patients with schizophrenia. To address this issue, event-related brain potentials (ERPs) were recorded from 20 symptomatically remitted patients with schizophrenia and 20 healthy controls during an event-based PM paradigm. Behavioral results showed that symptomatically remitted patients with schizophrenia performed poorly on the PM task compared with healthy controls. On the neural level, the N300, a component of the ERPs related to PM cue detection, was reliable across these two groups, suggesting a degree of functional recovery of processes supporting cue detection in patients with symptomatically remitted schizophrenia. By contrast, the amplitude of the prospective positivity, a component of the ERPs related to PM intention retrieval, was significantly attenuated in symptomatically remitted schizophrenia patients relative to healthy controls. Furthermore, a significant positive correlation between the amplitude of the prospective positivity and accuracy on the PM task was found in those patients, indicating that patients’ poor performance on this task may result from the failure to recover PM cue-induced intention from memory. These results provide evidence for the existence of altered PM processing in patients with symptomatically remitted schizophrenia, which is characterized by a selective deficit in retrospective component (intention retrieval) of PM. Therefore, these findings shed new light on the neurophysiological processes underlying PM in schizophrenia patients during clinical remission. PMID:26483650

  18. Grapheme-color synesthesia can enhance immediate memory without disrupting the encoding of relational cues.

    PubMed

    Gibson, Bradley S; Radvansky, Gabriel A; Johnson, Ann C; McNerney, M Windy

    2012-12-01

    Previous evidence has suggested that grapheme-color synesthesia can enhance memory for words, but little is known about how these photisms cue retrieval. Often, the encoding of specific features of individual words can disrupt the encoding of ordered relations between words, resulting in an overall decrease in recall accuracy. Here we show that the photisms arising from grapheme-color synesthesia do not function like these item-specific cues. The influences of high and low word frequency on the encoding of ordered relations and the accuracy of immediate free recall were compared across a group of 10 synesthetes and 48 nonsynesthetes. The main findings of Experiment 1 showed that the experience of synesthesia had no adverse effect on the encoding of ordered relations (as measured by input-output correspondence); furthermore, it enhanced recall accuracy in a strictly additive fashion across the two word frequency conditions. Experiment 2 corroborated these findings by showing that the synesthetes only outperformed the nonsynesthetes when the materials involved words and letters, not when they involved digits and spatial locations. Altogether, the present findings suggest that synesthesia can boost immediate memory performance without disrupting the encoding of ordered relations. PMID:22836925

  19. Relations between prospective memory, cognitive abilities, and brain structure in adolescents who vary in prenatal drug exposure

    PubMed Central

    Robey, Alison; Buckingham-Howes, Stacy; Salmeron, Betty Jo; Black, Maureen M.; Riggins, Tracy

    2014-01-01

    This investigation examined how prospective memory (PM) relates to cognitive abilities (i.e., executive function, attention, working memory, and retrospective memory), and brain structure in adolescents who vary in prenatal drug exposure (PDE). The sample included 105 (55 female, 50 male) urban, primarily African American adolescents (mean age 15.5 years) from low socioeconomic status (SES) families; 56% (n=59) were prenatally exposed to drugs (heroin and/or cocaine) and 44% (n=46) were not prenatally exposed, but similar in age, gender, race, and SES. Executive functioning, attentional control, working memory, retrospective memory, and overall cognitive ability were assessed by validated performance measures. Executive functioning was also measured by caregiver report. A subset of 52 adolescents completed MRI scans, which provided measures of subcortical gray matter volumes and thickness of prefrontal, parietal and temporal cortices. Results revealed no differences in PM performance by PDE status, even after adjusting for age and IQ. Executive function, retrospective memory, cortical thickness in frontal and parietal regions, and volume of subcortical regions (i.e., putamen and hippocampus) were related to PM performance in the sample overall, even after adjusting for age, IQ, and total gray matter volume. Findings suggest that variations in PM ability during adolescence are robustly related to individual differences in cognitive abilities, in particular executive function and retrospective memory, and brain structure, but do not vary by PDE status. PMID:24630759

  20. The Incidental Influence of Memories of Past Eating Occasions on Consumers’ Emotional Responses to Food and Food-Related Behaviors

    PubMed Central

    Piqueras-Fiszman, Betina; Jaeger, Sara R.

    2016-01-01

    Our memories of past eating experiences are influential in shaping food preferences and consumption behavior, and the emotions that people associate to these memories are linked to their attitudes toward foods and their everyday food-related behaviors. This work studies the impact that food-related memories have on peoples’ emotional state and how this state is projected in a subsequent evaluation of images pertaining to food and food-related behaviors. Focus is placed on guilt and shame emotions. Through an online survey, three memories were investigated (a positive meal, a routine evening meal, and an overeating occasion) among UK consumers (N = 710). Participants primed with the overeating memory evaluated images related to junk food as conveying more feelings of guilt and shame than did participants primed with the memory of a positive meal. Moreover, this effect was moderated by participants’ dietary restraint status. Participants classified as having a high dietary restraint had stronger associations with the emotions guilt and shame than participants classified as low in dietary restraint. In contrast, a memory of a positive meal did not lead to positive valuations of any of the food-related images shown. Overall, the findings from the present study illustrate the partial impact that personal food memories have on consumers’ emotional response toward food-related issues, which in turn has the potential to affect future behavior. This study therefore contributes to the literature about cognitive effects on food attitudes and behavior. Furthermore, the results suggest that the empirical approach may be tapping into possibly unconscious emotions toward foods and food-related behavior. PMID:27445911

  1. The Incidental Influence of Memories of Past Eating Occasions on Consumers' Emotional Responses to Food and Food-Related Behaviors.

    PubMed

    Piqueras-Fiszman, Betina; Jaeger, Sara R

    2016-01-01

    Our memories of past eating experiences are influential in shaping food preferences and consumption behavior, and the emotions that people associate to these memories are linked to their attitudes toward foods and their everyday food-related behaviors. This work studies the impact that food-related memories have on peoples' emotional state and how this state is projected in a subsequent evaluation of images pertaining to food and food-related behaviors. Focus is placed on guilt and shame emotions. Through an online survey, three memories were investigated (a positive meal, a routine evening meal, and an overeating occasion) among UK consumers (N = 710). Participants primed with the overeating memory evaluated images related to junk food as conveying more feelings of guilt and shame than did participants primed with the memory of a positive meal. Moreover, this effect was moderated by participants' dietary restraint status. Participants classified as having a high dietary restraint had stronger associations with the emotions guilt and shame than participants classified as low in dietary restraint. In contrast, a memory of a positive meal did not lead to positive valuations of any of the food-related images shown. Overall, the findings from the present study illustrate the partial impact that personal food memories have on consumers' emotional response toward food-related issues, which in turn has the potential to affect future behavior. This study therefore contributes to the literature about cognitive effects on food attitudes and behavior. Furthermore, the results suggest that the empirical approach may be tapping into possibly unconscious emotions toward foods and food-related behavior. PMID:27445911

  2. Individual Differences in Young Children's Suggestibility: Relations to Event Memory, Language Abilities, Working Memory, and Executive Functioning

    ERIC Educational Resources Information Center

    Roebers, C.M.; Schneider, W.

    2005-01-01

    In this paper, two empirical studies are presented in which an attempt was made to explain individual differences in two different aspects of 4-year-olds' suggestibility, that is, their ability to resist false suggestions and memory impairments due to prior misinformation. As sources of individual differences cognitive skills along the information…

  3. Memory Effects of Speech and Gesture Binding: Cortical and Hippocampal Activation in Relation to Subsequent Memory Performance

    ERIC Educational Resources Information Center

    Straube, Benjamin; Green, Antonia; Weis, Susanne; Chatterjee, Anjan; Tilo, Kircher

    2009-01-01

    In human face-to-face communication, the content of speech is often illustrated by coverbal gestures. Behavioral evidence suggests that gestures provide advantages in the comprehension and memory of speech. Yet, how the human brain integrates abstract auditory and visual information into a common representation is not known. Our study investigates…

  4. Transistor memory devices with large memory windows, using multi-stacking of densely packed, hydrophobic charge trapping metal nanoparticle array

    NASA Astrophysics Data System (ADS)

    Cho, Ikjun; Kim, Beom Joon; Ryu, Sook Won; Cho, Jeong Ho; Cho, Jinhan

    2014-12-01

    Organic field-effect transistor (OFET) memories have rapidly evolved from low-cost and flexible electronics with relatively low-memory capacities to memory devices that require high-capacity memory such as smart memory cards or solid-state hard drives. Here, we report the high-capacity OFET memories based on the multilayer stacking of densely packed hydrophobic metal NP layers in place of the traditional transistor memory systems based on a single charge trapping layer. We demonstrated that the memory performances of devices could be significantly enhanced by controlling the adsorption isotherm behavior, multilayer stacking structure and hydrophobicity of the metal NPs. For this study, tetraoctylammonium (TOA)-stabilized Au nanoparticles (TOA-AuNPs) were consecutively layer-by-layer (LbL) assembled with an amine-functionalized poly(amidoamine) dendrimer (PAD). The formed (PAD/TOA-AuNP)n films were used as a multilayer stacked charge trapping layer at the interface between the tunneling dielectric layer and the SiO2 gate dielectric layer. For a single AuNP layer (i.e. PAD/TOA-AuNP)1) with a number density of 1.82 × 1012 cm-2, the memory window of the OFET memory device was measured to be approximately 97 V. The multilayer stacked OFET memory devices prepared with four AuNP layers exhibited excellent programmable memory properties (i.e. a large memory window (ΔVth) exceeding 145 V, a fast switching speed (1 μs), a high program/erase (P/E) current ratio (greater than 106) and good electrical reliability) during writing and erasing over a relatively short time scale under an operation voltage of 100 V applied at the gate.

  5. Disruption of caudate working memory activation in chronic blast-related traumatic brain injury.

    PubMed

    Newsome, Mary R; Durgerian, Sally; Mourany, Lyla; Scheibel, Randall S; Lowe, Mark J; Beall, Erik B; Koenig, Katherine A; Parsons, Michael; Troyanskaya, Maya; Reece, Christine; Wilde, Elisabeth; Fischer, Barbara L; Jones, Stephen E; Agarwal, Rajan; Levin, Harvey S; Rao, Stephen M

    2015-01-01

    Mild to moderate traumatic brain injury (TBI) due to blast exposure is frequently diagnosed in veterans returning from the wars in Iraq and Afghanistan. However, it is unclear whether neural damage resulting from blast TBI differs from that found in TBI due to blunt-force trauma (e.g., falls and motor vehicle crashes). Little is also known about the effects of blast TBI on neural networks, particularly over the long term. Because impairment in working memory has been linked to blunt-force TBI, the present functional magnetic resonance imaging (fMRI) study sought to investigate whether brain activation in response to a working memory task would discriminate blunt-force from blast TBI. Twenty-five veterans (mean age = 29.8 years, standard deviation = 6.01 years, 1 female) who incurred TBI due to blast an average of 4.2 years prior to enrollment and 25 civilians (mean age = 27.4 years, standard deviation = 6.68 years, 4 females) with TBI due to blunt-force trauma performed the Sternberg Item Recognition Task while undergoing fMRI. The task involved encoding 1, 3, or 5 items in working memory. A group of 25 veterans (mean age = 29.9 years, standard deviation = 5.53 years, 0 females) and a group of 25 civilians (mean age = 27.3 years, standard deviation = 5.81 years, 0 females) without history of TBI underwent identical imaging procedures and served as controls. Results indicated that the civilian TBI group and both control groups demonstrated a monotonic relationship between working memory set size and activation in the right caudate during encoding, whereas the blast TBI group did not (p < 0.05, corrected for multiple comparisons using False Discovery Rate). Blast TBI was also associated with worse performance on the Sternberg Item Recognition Task relative to the other groups, although no other group differences were found on neuropsychological measures of episodic memory, inhibition, and general processing speed. These results could not be

  6. Disruption of caudate working memory activation in chronic blast-related traumatic brain injury

    PubMed Central

    Newsome, Mary R.; Durgerian, Sally; Mourany, Lyla; Scheibel, Randall S.; Lowe, Mark J.; Beall, Erik B.; Koenig, Katherine A.; Parsons, Michael; Troyanskaya, Maya; Reece, Christine; Wilde, Elisabeth; Fischer, Barbara L.; Jones, Stephen E.; Agarwal, Rajan; Levin, Harvey S.; Rao, Stephen M.

    2015-01-01

    Mild to moderate traumatic brain injury (TBI) due to blast exposure is frequently diagnosed in veterans returning from the wars in Iraq and Afghanistan. However, it is unclear whether neural damage resulting from blast TBI differs from that found in TBI due to blunt-force trauma (e.g., falls and motor vehicle crashes). Little is also known about the effects of blast TBI on neural networks, particularly over the long term. Because impairment in working memory has been linked to blunt-force TBI, the present functional magnetic resonance imaging (fMRI) study sought to investigate whether brain activation in response to a working memory task would discriminate blunt-force from blast TBI. Twenty-five veterans (mean age = 29.8 years, standard deviation = 6.01 years, 1 female) who incurred TBI due to blast an average of 4.2 years prior to enrollment and 25 civilians (mean age = 27.4 years, standard deviation = 6.68 years, 4 females) with TBI due to blunt-force trauma performed the Sternberg Item Recognition Task while undergoing fMRI. The task involved encoding 1, 3, or 5 items in working memory. A group of 25 veterans (mean age = 29.9 years, standard deviation = 5.53 years, 0 females) and a group of 25 civilians (mean age = 27.3 years, standard deviation = 5.81 years, 0 females) without history of TBI underwent identical imaging procedures and served as controls. Results indicated that the civilian TBI group and both control groups demonstrated a monotonic relationship between working memory set size and activation in the right caudate during encoding, whereas the blast TBI group did not (p < 0.05, corrected for multiple comparisons using False Discovery Rate). Blast TBI was also associated with worse performance on the Sternberg Item Recognition Task relative to the other groups, although no other group differences were found on neuropsychological measures of episodic memory, inhibition, and general processing speed. These results could not be

  7. 18. DETAIL VIEW OF NONSUBMERSIBLE TAINTER GATE, SHOWING GATES, GATE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. DETAIL VIEW OF NON-SUBMERSIBLE TAINTER GATE, SHOWING GATES, GATE ARMS, PIERS AND DAM BRIDGE, LOOKING SOUTHEAST - Upper Mississippi River 9-Foot Channel, Lock & Dam No. 9, Lynxville, Crawford County, WI

  8. 16. DETAIL VIEW OF SUBMERSIBLE TAINTER GATE, SHOWING GATE, GATE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. DETAIL VIEW OF SUBMERSIBLE TAINTER GATE, SHOWING GATE, GATE ARM, TRUNNION PIN AND PIER, LOOKING NORTHEAST - Upper Mississippi River 9-Foot Channel, Lock & Dam No. 8, On Mississippi River near Houston County, MN, Genoa, Vernon County, WI

  9. Distractor-relevance determines whether task-switching enhances or impairs distractor memory.

    PubMed

    Chiu, Yu-Chin; Egner, Tobias

    2016-01-01

    Richter and Yeung (2012) recently documented a novel task-switching effect, a switch-induced reduction in "memory selectivity," characterized by relatively enhanced memory for distractor stimuli and impaired memory for target stimuli encountered on switch trials compared with repeat trials. One interpretation of this finding argues that task-switching involves opening a "gate" to working memory, which promotes updating of the task-set, but at the same time allows for increased distraction from task-irrelevant information. However, in that study, the distractor category on a switch trial also represented the task-relevant target category from the previous trial. Thus, distractors were only intermittently task-irrelevant, such that switch-enhanced distractor memory could alternatively be because of remnant attention to the previously relevant stimuli, or "task-set inertia." Here we adjudicated between the open-gate and the task-set inertia accounts of switch-enhanced distractor memory by assessing incidental memory for distractors that were either intermittently or always task-irrelevant. While we replicated switch-enhanced distractor memory in the intermittently irrelevant distractor condition, this effect was reversed in the always-irrelevant distractor condition. These results speak against the open-gate account, and instead indicate that switch-enhanced distractor memory arises from task-set inertia, and will not be observed for truly task-irrelevant stimuli presented during switching. PMID:26594883

  10. Reversal of aging-related emotional memory deficits by norepinephrine via regulating the stability of surface AMPA receptors.

    PubMed

    Luo, Yi; Zhou, Jun; Li, Ming-Xing; Wu, Peng-Fei; Hu, Zhuang-Li; Ni, Lan; Jin, You; Chen, Jian-Guo; Wang, Fang

    2015-04-01

    Aging-related emotional memory deficit is a well-known complication in Alzheimer's disease and normal aging. However, little is known about its molecular mechanism. To address this issue, we examined the role of norepinephrine (NE) and its relevant drug desipramine in the regulation of hippocampal long-term potentiation (LTP), surface expression of AMPA receptor, and associative fear memory in rats. We found that there was a defective regulation of NE content and AMPA receptor trafficking during fear conditioning, which were accompanied by impaired emotional memory and LTP in aged rats. Furthermore, we also found that the exogenous upregulation of NE ameliorated the impairment of LTP and emotional memory via enhancing AMPA receptor trafficking in aged rats, and the downregulation of NE impaired LTP in adult rats. Finally, acute treatment with NE or desipramine rescued the impaired emotional memory in aged rats. These results imply a pivotal role for NE in synaptic plasticity and associative fear memory in aging rats and suggest that desipramine is a potential candidate for treating aging-related emotional memory deficit. PMID:25564942

  11. Neonatal anoxia in rats: hippocampal cellular and subcellular changes related to cell death and spatial memory.

    PubMed

    Takada, S H; dos Santos Haemmerle, C A; Motta-Teixeira, L C; Machado-Nils, A V; Lee, V Y; Takase, L F; Cruz-Rizzolo, R J; Kihara, A H; Xavier, G F; Watanabe, I-S; Nogueira, M I

    2015-01-22

    Neonatal anoxia in rodents has been used to understand brain changes and cognitive dysfunction following asphyxia. This study investigated the time-course of cellular and subcellular changes and hippocampal cell death in a non-invasive model of anoxia in neonatal rats, using Terminal deoxynucleotidyl transferase-mediated dUTP Nick End Labeling (TUNEL) to reveal DNA fragmentation, Fluoro-Jade® B (FJB) to show degenerating neurons, cleaved caspase-3 immunohistochemistry (IHC) to detect cells undergoing apoptosis, and transmission electron microscopy (TEM) to reveal fine ultrastructural changes related to cell death. Anoxia was induced by exposing postnatal day 1 (P1) pups to a flow of 100% gaseous nitrogen for 25 min in a chamber maintained at 37 °C. Control rats were similarly exposed to this chamber but with air flow instead of nitrogen. Brain changes following anoxia were evaluated at postnatal days 2, 14, 21 and 60 (P2, P14, P21 and P60). In addition, spatial reference memory following anoxia and control treatments was evaluated in the Morris water maze, starting at P60. Compared to their respective controls, P2 anoxic rats exhibited (1) higher TUNEL labeling in cornus ammonis (CA) 1 and the dentate gyrus (DG), (2) higher FJB-positive cells in the CA2-3, and (3) somato-dendritic swelling, mitochondrial injury and chromatin condensation in irregular bodies, as well as other subcellular features indicating apoptosis, necrosis, autophagy and excitotoxicity in the CA1, CA2-3 and DG, as revealed by TEM. At P14, P21 and P60, both groups showed small numbers of TUNEL-positive and FJB-positive cells. Stereological analysis at P2, P14, P21 and P60 revealed a lack of significant differences in cleaved caspase-3 IHC between anoxic and control subjects. These results suggest that the type of hippocampal cell death following neonatal anoxia is likely independent of caspase-3 activation. Neonatal anoxia induced deficits in acquisition and performance of spatial reference

  12. Alzheimer’s Disease and Age-Related Memory Decline (Preclinical)

    PubMed Central

    Terry, Alvin V.; Callahan, Patrick M.; Hall, Brandon; Webster, Scott J.

    2011-01-01

    An unfortunate result of the rapid rise in geriatric populations worldwide is the increasing prevalence of age-related cognitive disorders such as Alzheimer’s disease (AD). AD is a devastating neurodegenerative illness that is characterized by a profound impairment of cognitive function, marked physical disability, and an enormous economic burden on the afflicted individual, caregivers, and society in general. The rise in elderly populations is also resulting in an increase in individuals with related (potentially treatable) conditions such as “Mild Cognitive Impairment” (MCI) which is characterized by a less severe (but abnormal) level of cognitive impairment and a high-risk for developing dementia. Even in the absence of a diagnosable disorder of cognition (e.g., AD, MCI), the perception of increased forgetfulness and declining mental function is a clear source of apprehension in the elderly. This is a valid concern given that even a modest impairment of cognitive function is likely to be associated with significant disability in a rapidly evolving, technology-based society. Unfortunately, the currently available therapies designed to improve cognition (i.e., for AD and other forms of dementia) are limited by modest efficacy, adverse side effects, and their effects on cognitive function are not sustained over time. Accordingly, it is incumbent on the scientific community to develop safer and more effective therapies that improve and/or sustain cognitive function in the elderly allowing them to remain mentally active and productive for as long as possible. As diagnostic criteria for memory disorders evolve, the demand for pro-cognitive therapeutic agents is likely to surpass AD and dementia to include MCI and potentially even less severe forms of memory decline. The purpose of this review is to provide an overview of the contemporary therapeutic targets and preclinical pharmacologic approaches (with representative drug examples) designed to enhance memory

  13. Mediating Effects of Working Memory in the Relation Between Rapid Automatized Naming and Chinese Reading Comprehension.

    PubMed

    Weng, Xiaoqian; Li, Guangze; Li, Rongbao

    2016-08-01

    This study examined the mediating role of working memory (WM) in the relation between rapid automatized naming (RAN) and Chinese reading comprehension. Three tasks assessing differentially visual and verbal components of WM were programmed by E-prime 2.0. Data collected from 55 Chinese college students were analyzed using correlations and hierarchical regression methods to determine the connection among RAN, reading comprehension, and WM components. Results showed that WM played a significant mediating role in the RAN-reading relation and that auditory WM made stronger contributions than visual WM. Taking into account of the multi-component nature of WM and the specificity of Chinese reading processing, this study discussed the mediating powers of the WM components, particularly auditory WM, further clarifying the possible components involved in the RAN-reading relation and thus providing some insight into the complicated Chinese reading process. PMID:26187379

  14. Contribution of working memory processes to relational matching-to-sample performance in baboons (Papio papio).

    PubMed

    Maugard, Anaïs; Marzouki, Yousri; Fagot, Joël

    2013-11-01

    Recent studies of monkeys and apes have shown that these animals can solve relational-matching-to-sample (RMTS) problems, suggesting basic abilities for analogical reasoning. However, doubts remain as to the actual cognitive strategies adopted by nonhuman primates in this task. Here, we used dual-task paradigms to test 10 baboons in the RMTS problem under three conditions of memory load. Our three test conditions allowed different predictions, depending on the strategy (i.e., flat memorization of the percept, reencoding of the percept, or relational processing) that they might use to solve RMTS problems. Results support the idea that the baboons process both the items and the abstract (same and different) relations in this task. PMID:23772798

  15. Rewriting the valuation and salience of alcohol-related stimuli via memory reconsolidation.

    PubMed

    Das, R K; Lawn, W; Kamboj, S K

    2015-01-01

    The transient period of memory instability that can be triggered when memories are retrieved under certain conditions offers an opportunity to modify the maladaptive memories at the heart of substance use disorders (SUDs). However, very well-learned memories (such as those in excessive drinking and alcohol use disorders) are resistant to destabilisation when retrieved or may not destabilise at all. Memory retrieval and intervention procedures that reliably destabilise and update maladaptive motivational memories may help to improve the long-term treatment of SUDs. In 59 hazardous drinkers, we tested a novel retrieval procedure for destabilising well-learned cue-drinking memory networks that maximises prediction error (PE) via guided expectancy violation during retrieval of these memories. This was compared with a retrieval procedure without PE and no-retrieval controls. We subsequently counterconditioned alcohol cues with disgusting tastes and images in all groups and assessed responding to alcohol stimuli 1 week later. Counterconditioning following PE retrieval produced generalised reductions in oculomotor attentional bias, explicit valuation and outcome expectancies in response to alcohol cues 1 week after intervention, evidence of updating of distributed motivational drinking memory networks. These findings demonstrate that well-learned cue-drinking memories can be destabilised and that learning history need not constrain memory destabilisation if PE is maximised at retrieval. Broad rewriting of diverse aspects of maladaptive memory by counterconditioning is achievable following this procedure. The procedure described may provide a platform for the development of novel memory-modifying interventions for SUDs. PMID:26393491

  16. Encoding-related EEG oscillations during memory formation are modulated by mood state

    PubMed Central

    Bajbouj, Malek

    2014-01-01

    Mood states have a strong impact on how we process incoming information. It has been proposed that positive mood facilitates elaborative, relational encoding, whereas negative mood promotes a more careful, stimulus-driven encoding style. Previous electrophysiological studies have linked successful information encoding to power increases in slow (<8 Hz) delta/theta and fast (>30 Hz) gamma oscillations, as well as to power decreases in midrange (8–30 Hz) alpha/beta oscillations. Whether different mood states modulate encoding-related oscillations has not been investigated yet. In order to address this question, we used an experimental mood induction procedure and recorded electroencephalograms from 20 healthy participants while they performed a free recall memory task after positive and negative mood induction. We found distinct oscillatory patterns in positive and negative mood. Successful encoding in positive mood was accompanied by widespread power increases in the delta band, whereas encoding success in negative mood was specifically accompanied by frontal power decreases in the beta band. On the behavioral level, memory performance was enhanced in positive mood. Our findings show that mood differentially modulates the neural correlates of successful information encoding and thus contribute to an understanding of how mood shapes different processing styles. PMID:24464848

  17. Simulating Navigation with Virtual 3d Geovisualizations - a Focus on Memory Related Factors

    NASA Astrophysics Data System (ADS)

    Lokka, I.; Çöltekin, A.

    2016-06-01

    The use of virtual environments (VE) for navigation-related studies, such as spatial cognition and path retrieval has been widely adopted in cognitive psychology and related fields. What motivates the use of VEs for such studies is that, as opposed to real-world, we can control for the confounding variables in simulated VEs. When simulating a geographic environment as a virtual world with the intention to train navigational memory in humans, an effective and efficient visual design is important to facilitate the amount of recall. However, it is not yet clear what amount of information should be included in such visual designs intended to facilitate remembering: there can be too little or too much of it. Besides the amount of information or level of detail, the types of visual features (`elements' in a visual scene) that should be included in the representations to create memorable scenes and paths must be defined. We analyzed the literature in cognitive psychology, geovisualization and information visualization, and identified the key factors for studying and evaluating geovisualization designs for their function to support and strengthen human navigational memory. The key factors we identified are: i) the individual abilities and age of the users, ii) the level of realism (LOR) included in the representations and iii) the context in which the navigation is performed, thus specific tasks within a case scenario. Here we present a concise literature review and our conceptual development for follow-up experiments.

  18. Selective alterations of neurons and circuits related to early memory loss in Alzheimer’s disease

    PubMed Central

    Llorens-Martín, Maria; Blazquez-Llorca, Lidia; Benavides-Piccione, Ruth; Rabano, Alberto; Hernandez, Felix; Avila, Jesus; DeFelipe, Javier

    2014-01-01

    A progressive loss of episodic memory is a well-known clinical symptom that characterizes Alzheimer’s disease (AD). The beginning of this loss of memory has been associated with the very early, pathological accumulation of tau and neuronal degeneration observed in the entorhinal cortex (EC). Tau-related pathology is thought to then spread progressively to the hippocampal formation and other brain areas as the disease progresses. The major cortical afferent source of the hippocampus and dentate gyrus is the EC through the perforant pathway. At least two main circuits participate in the connection between EC and the hippocampus; one originating in layer II and the other in layer III of the EC giving rise to the classical trisynaptic (ECII → dentate gyrus → CA3 → CA1) and monosynaptic (ECIII → CA1) circuits. Thus, the study of the early pathological changes in these circuits is of great interest. In this review, we will discuss mainly the alterations of the granule cell neurons of the dentate gyrus and the atrophy of CA1 pyramidal neurons that occur in AD in relation to the possible differential alterations of these two main circuits. PMID:24904307

  19. Age-Related Declines in Early Sensory Memory: Identification of Rapid Auditory and Visual Stimulus Sequences

    PubMed Central

    Fogerty, Daniel; Humes, Larry E.; Busey, Thomas A.

    2016-01-01

    Age-related temporal-processing declines of rapidly presented sequences may involve contributions of sensory memory. This study investigated recall for rapidly presented auditory (vowel) and visual (letter) sequences presented at six different stimulus onset asynchronies (SOA) that spanned threshold SOAs for sequence identification. Younger, middle-aged, and older adults participated in all tasks. Results were investigated at both equivalent performance levels (i.e., SOA threshold) and at identical physical stimulus values (i.e., SOAs). For four-item sequences, results demonstrated best performance for the first and last items in the auditory sequences, but only the first item for visual sequences. For two-item sequences, adults identified the second vowel or letter significantly better than the first. Overall, when temporal-order performance was equated for each individual by testing at SOA thresholds, recall accuracy for each position across the age groups was highly similar. These results suggest that modality-specific processing declines of older adults primarily determine temporal-order performance for rapid sequences. However, there is some evidence for a second amodal processing decline in older adults related to early sensory memory for final items in a sequence. This selective deficit was observed particularly for longer sequence lengths and was not accounted for by temporal masking. PMID:27199737

  20. Event-related brain potential correlates of two states of conscious awareness in memory

    PubMed Central

    Düzel, Emrah; Yonelinas, Andrew P.; Mangun, George R.; Heinze, Hans-Jochen; Tulving, Endel

    1997-01-01

    We report an event-related potential (ERP) experiment of human recognition memory that explored the relation between conscious awareness and electrophysiological activity of the brain. We recorded ERPs from healthy adults while they made “remember” and “know” recognition judgments about previously seen words. These two kinds of judgments reflect “autonoetic” and “noetic” awareness, respectively. The ERP effects differed between the two kinds of awareness while they were similar for “true” and “false” recognition. Noetic awareness was associated with a temporoparietal positivity in the N400 range (325–600 ms) and a late (600–1,000 ms) frontocentral negativity, whereas autonoetic awareness was associated with a widespread, late, bifrontal and left parietotemporal (600–1000 ms) positivity. In the very late (1,300–1,900 ms) time window, a right frontal positivity was observed for both remember and know judgments of both true and false targets. These results provide physiological evidence for two types of conscious awareness in episodic memory retrieval. PMID:9159185

  1. Black phosphorus nonvolatile transistor memory.

    PubMed

    Lee, Dain; Choi, Yongsuk; Hwang, Euyheon; Kang, Moon Sung; Lee, Seungwoo; Cho, Jeong Ho

    2016-04-28

    We demonstrated nanofloating gate transistor memory devices (NFGTMs) using mechanically-exfoliated few-layered black phosphorus (BP) channels and gold nanoparticle (AuNPs) charge trapping layers. The resulting BP-NFGTMs exhibited excellent memory performances, including the five-level data storage, large memory window (58.2 V), stable retention (10(4) s), and cyclic endurance (1000 cycles). PMID:27074903

  2. MHC Class I Immune Proteins Are Critical for Hippocampus-Dependent Memory and Gate NMDAR-Dependent Hippocampal Long-Term Depression

    ERIC Educational Resources Information Center

    Nelson, P. Austin; Sage, Jennifer R.; Wood, Suzanne C.; Davenport, Christopher M.; Anagnostaras, Stephan G.; Boulanger, Lisa M.

    2013-01-01

    Memory impairment is a common feature of conditions that involve changes in inflammatory signaling in the brain, including traumatic brain injury, infection, neurodegenerative disorders, and normal aging. However, the causal importance of inflammatory mediators in cognitive impairments in these conditions remains unclear. Here we show that…

  3. Music mnemonics aid Verbal Memory and Induce Learning – Related Brain Plasticity in Multiple Sclerosis

    PubMed Central

    Thaut, Michael H.; Peterson, David A.; McIntosh, Gerald C.; Hoemberg, Volker

    2014-01-01

    Recent research on music and brain function has suggested that the temporal pattern structure in music and rhythm can enhance cognitive functions. To further elucidate this question specifically for memory, we investigated if a musical template can enhance verbal learning in patients with multiple sclerosis (MS) and if music-assisted learning will also influence short-term, system-level brain plasticity. We measured systems-level brain activity with oscillatory network synchronization during music-assisted learning. Specifically, we measured the spectral power of 128-channel electroencephalogram (EEG) in alpha and beta frequency bands in 54 patients with MS. The study sample was randomly divided into two groups, either hearing a spoken or a musical (sung) presentation of Rey’s auditory verbal learning test. We defined the “learning-related synchronization” (LRS) as the percent change in EEG spectral power from the first time the word was presented to the average of the subsequent word encoding trials. LRS differed significantly between the music and the spoken conditions in low alpha and upper beta bands. Patients in the music condition showed overall better word memory and better word order memory and stronger bilateral frontal alpha LRS than patients in the spoken condition. The evidence suggests that a musical mnemonic recruits stronger oscillatory network synchronization in prefrontal areas in MS patients during word learning. It is suggested that the temporal structure implicit in musical stimuli enhances “deep encoding” during verbal learning and sharpens the timing of neural dynamics in brain networks degraded by demyelination in MS. PMID:24982626

  4. "Plateau"-related summary statistics are uninformative for comparing working memory models.

    PubMed

    van den Berg, Ronald; Ma, Wei Ji

    2014-10-01

    Performance on visual working memory tasks decreases as more items need to be remembered. Over the past decade, a debate has unfolded between proponents of slot models and slotless models of this phenomenon (Ma, Husain, Bays (Nature Neuroscience 17, 347-356, 2014). Zhang and Luck (Nature 453, (7192), 233-235, 2008) and Anderson, Vogel, and Awh (Attention, Perception, Psychophys 74, (5), 891-910, 2011) noticed that as more items need to be remembered, "memory noise" seems to first increase and then reach a "stable plateau." They argued that three summary statistics characterizing this plateau are consistent with slot models, but not with slotless models. Here, we assess the validity of their methods. We generated synthetic data both from a leading slot model and from a recent slotless model and quantified model evidence using log Bayes factors. We found that the summary statistics provided at most 0.15 % of the expected model evidence in the raw data. In a model recovery analysis, a total of more than a million trials were required to achieve 99 % correct recovery when models were compared on the basis of summary statistics, whereas fewer than 1,000 trials were sufficient when raw data were used. Therefore, at realistic numbers of trials, plateau-related summary statistics are highly unreliable for model comparison. Applying the same analyses to subject data from Anderson et al. (Attention, Perception, Psychophys 74, (5), 891-910, 2011), we found that the evidence in the summary statistics was at most 0.12 % of the evidence in the raw data and far too weak to warrant any conclusions. The evidence in the raw data, in fact, strongly favored the slotless model. These findings call into question claims about working memory that are based on summary statistics. PMID:24719235

  5. Music mnemonics aid Verbal Memory and Induce Learning - Related Brain Plasticity in Multiple Sclerosis.

    PubMed

    Thaut, Michael H; Peterson, David A; McIntosh, Gerald C; Hoemberg, Volker

    2014-01-01

    Recent research on music and brain function has suggested that the temporal pattern structure in music and rhythm can enhance cognitive functions. To further elucidate this question specifically for memory, we investigated if a musical template can enhance verbal learning in patients with multiple sclerosis (MS) and if music-assisted learning will also influence short-term, system-level brain plasticity. We measured systems-level brain activity with oscillatory network synchronization during music-assisted learning. Specifically, we measured the spectral power of 128-channel electroencephalogram (EEG) in alpha and beta frequency bands in 54 patients with MS. The study sample was randomly divided into two groups, either hearing a spoken or a musical (sung) presentation of Rey's auditory verbal learning test. We defined the "learning-related synchronization" (LRS) as the percent change in EEG spectral power from the first time the word was presented to the average of the subsequent word encoding trials. LRS differed significantly between the music and the spoken conditions in low alpha and upper beta bands. Patients in the music condition showed overall better word memory and better word order memory and stronger bilateral frontal alpha LRS than patients in the spoken condition. The evidence suggests that a musical mnemonic recruits stronger oscillatory network synchronization in prefrontal areas in MS patients during word learning. It is suggested that the temporal structure implicit in musical stimuli enhances "deep encoding" during verbal learning and sharpens the timing of neural dynamics in brain networks degraded by demyelination in MS. PMID:24982626

  6. ESTROGENS AND AGE-RELATED MEMORY DECLINE IN RODENTS: WHAT HAVE WE LEARNED AND WHERE DO WE GO FROM HERE?

    PubMed Central

    Frick, Karyn M.

    2009-01-01

    The question of whether ovarian hormone therapy can prevent or reduce age-related memory decline in menopausal women has been the subject of much recent debate. Although numerous studies have demonstrated a beneficial effect of estrogen and/or progestin therapy for certain types of memory in menopausal women, recent clinical trials suggest that such therapy actually increases the risk of cognitive decline and dementia. Because rodent models have been frequently used to examine the effects of age and/or ovarian hormone deficiency on mnemonic function, rodent models of age-related hormone and memory decline may be useful in helping to resolve this issue. This review will focus on evidence suggesting that estradiol modulates memory, particularly hippocampal-dependent memory, in young and aging female rats and mice. Various factors affecting the mnemonic response to estradiol in aging females will be highlighted to illustrate the complications inherent to studies of estrogen therapy in aging females. Avenues for future development of estradiol-based therapies will also be discussed, and it is argued that an approach to drug development based on identifying the molecular mechanisms underlying estrogenic modulation of memory may lead to promising future treatments for reducing age-related mnemonic decline. PMID:18835561

  7. Event-related potential study of intentional and incidental retrieval of item and source memory during early childhood.

    PubMed

    Robey, Alison; Riggins, Tracy

    2016-07-01

    The event related potential (ERP) technique is a useful methodology for studying neural changes underlying memory development during childhood. However, systematic comparisons of differences in memory tasks and retrieval demands are lacking. To address this gap, the present study explored the effects of memory task (i.e., item versus source) and retrieval paradigm (i.e., intentional versus incidental) on 4- to 5-year-old children's memory performance and associated electrophysiological responses. Children were familiarized with items in a play-like setting and then asked to retrieve item or source memory details while their brain activity was recorded (intentional retrieval) or while they passively viewed images of the items with no explicit task (incidental retrieval). Memory assessments for the incidental groups followed ERP recording. Analyses of the ERP data suggested that the brain's response during intentional retrieval of source information differed from the other three conditions. These results are discussed within a two-component framework of memory development (e.g., Shing et al., 2010), and implications for future methodological decisions are presented. © 2016 Wiley Periodicals, Inc. Dev Psychobiol 58: 556-567, 2016. PMID:26969036

  8. Prospective Memory Performance in Non-Psychotic First-Degree Relatives of Patients with Schizophrenia: A Controlled Study

    PubMed Central

    Wang, Chuan-Yue; Ungvari, Gabor S.; Chiu, Helen F. K.; Correll, Christoph U.; Shum, David H. K.; Man, David; Liu, Deng-Tang; Xiang, Yu-Tao

    2014-01-01

    Objective We aimed at investigating prospective memory and its socio-demographic and neurocognitive correlates in non-psychotic, first-degree relatives (FDRs) of patients with schizophrenia compared to patients with first episode schizophrenia (FES), and healthy controls (HCs). Methods Forty-seven FES patients, 50 non-psychotic FDRs (23 offspring and 27 siblings) of patients with chronic schizophrenia (unrelated to the FES group) and 51 HCs were studied. The Chinese version of the Cambridge Prospective Memory Test (C-CAMPROMPT) was used to measure time-based prospective memory (TBPM) and event-based prospective memory (EBPM) performance. Other cognitive functions (involving respective memory and executive functions) were evaluated with standardized tests. Results After controlling for basic demographic characteristics including age, gender and educational level, there was a significant difference between FDRs, FES and HCs with respect to both TBPM (F(2,142) = 10.4, p<0.001) and EBPM (F(2,142) = 10.8, p<0.001). Multiple linear regression analyses revealed that lower scores of the Hopkins Verbal Learning Test-Revised (HVLT-R) and the STROOP Word-Color Test (SWCT) contributed to TBPM impairment, while lower educational level and higher scores of the Color Trails Test-2 (CTT-2) contributed to EBPM deficit in FDRs. Conclusions FDRs share similar but attenuated prospective memory impairments with schizophrenia patients, suggesting that prospective memory deficits may represent an endophenotype of schizophrenia. PMID:25365028

  9. Relations between Working Memory and Emergent Writing among Preschool-Aged Children

    ERIC Educational Resources Information Center

    Hoskyn, Maureen; Tzoneva, Irina

    2008-01-01

    The authors examined the nature of the working memory system that underlies age differences of young, preschool-aged children. Measures of working memory, short-term memory, articulation speed, general intelligence, and writing were administered to 166 Canadian preschool-aged children aged 3 to 5 years. Findings generally support the hypothesis…

  10. Relations between the Test of Variables of Attention (TOVA) and the Children's Memory Scale (CMS)

    ERIC Educational Resources Information Center

    Riccio, Cynthia A.; Garland, Beth H.; Cohen, Morris J.

    2007-01-01

    Objective: There is considerable overlap in the constructs of attention and memory. The objective of this study was to examine the relationship between the Test of Variables of Attention (TOVA), a measure of attention, to components of memory and learning as measured by the Children's Memory Scale (CMS). Method: Participants (N = 105) were…

  11. The Phenotypic and Genotypic Relation between Working Memory Speed and Capacity

    ERIC Educational Resources Information Center

    Polderman, Tinca J. C.; Stins, John F.; Posthuma, Danielle; Gosso, M. Florencia; Verhulst, Frank C.; Boomsma, Dorret I.

    2006-01-01

    This study examined the phenotypic and genotypic relationship between working memory speed (WMS) and working memory capacity (WMC) in 12-year-old twins and their siblings (N = 409). To asses WMS all children performed a reaction time task with three memory loads from which a basic mental speed measure and the derived slope were used. WMC was…

  12. Putting the Pieces Together: The Role of Dorsolateral Prefrontal Cortex in Relational Memory Encoding

    ERIC Educational Resources Information Center

    Blumenfeld, Robert S.; Parks, Colleen M.; Yonelinas, Andrew P.; Ranganath, Charan

    2011-01-01

    Results from fMRI have strongly supported the idea that the ventrolateral PFC (VLPFC) contributes to successful memory formation, but the role the dorsolateral PFC (DLPFC) in memory encoding is more controversial. Some findings suggest that the DLPFC is recruited when one is processing relationships between items in working memory, and this…

  13. Infants’ Visual Recognition Memory for a Series of Categorically Related Items

    ERIC Educational Resources Information Center

    Oakes, Lisa M.; Kovack-Lesh, Kristine A.

    2013-01-01

    Six-month-old infants' ("N" = 168) memory for individual items in a categorized list (e.g., images of dogs or cats) was examined to investigate the interactions between visual recognition memory, working memory, and categorization. In Experiments 1 and 2, infants were familiarized with six different cats or dogs, presented one at a time on a…

  14. Developmental Differences in Relations between Episodic Memory and Hippocampal Subregion Volume during Early Childhood

    ERIC Educational Resources Information Center

    Riggins, Tracy; Blankenship, Sarah L.; Mulligan, Elizabeth; Rice, Katherine; Redcay, Elizabeth

    2015-01-01

    Episodic memory shows striking improvement during early childhood. However, neural contributions to these behavioral changes are not well understood. This study examined associations between episodic memory and volume of subregions (head, body, and tail) of the hippocampus--a structure known to support episodic memory in school-aged children and…

  15. Individual Differences in Memory Updating in Relation to Arithmetic Problem Solving

    ERIC Educational Resources Information Center

    Passolunghi, Maria Chiara; Pazzaglia, Francesca

    2004-01-01

    The study investigates the relationship between memory updating and arithmetic word problem solving. Two groups of 35 fourth graders with high and low memory-updating abilities were selected from a sample of 89 children on the basis of an updating task used by Palladino et al. ["Memory & Cognition" 29 (2002) 344]. The two groups were required to…

  16. Structure and process in semantic memory: evidence from event-related brain potentials and reaction times.

    PubMed

    Kounios, J; Holcomb, P J

    1992-12-01

    Through scalp measurements of the electrical activity of the brain (event-related potentials, or ERPs) recorded while subjects verified the truth of sentences relating exemplars and categories (e.g., ALL DOGS ARE ANIMALS), inferences were made about aspects of semantic processing that were not directly reflected by overt responses. In particular, it is suggested that a negative ERP component that peaks about 400 ms after the onset of the sentence predicate (i.e., N400) is sensitive to structural aspects of semantic memory. The amplitude of this component was modulated by the relatedness of the subject and predicate terms, as well as the hierarchical level of both these terms, but was not sensitive to the truth value of a sentence. PMID:1431739

  17. BDNF val66met affects hippocampal volume and emotion-related hippocampal memory activity.

    PubMed

    Molendijk, M L; van Tol, M-J; Penninx, B W J H; van der Wee, N J A; Aleman, A; Veltman, D J; Spinhoven, P; Elzinga, B M

    2012-01-01

    The val(66)met polymorphism on the BDNF gene has been reported to explain individual differences in hippocampal volume and memory-related activity. These findings, however, have not been replicated consistently and no studies to date controlled for the potentially confounding impact of early life stress, such as childhood abuse, and psychiatric status. Using structural and functional MRI, we therefore investigated in 126 depressed and/or anxious patients and 31 healthy control subjects the effects of val(66)met on hippocampal volume and encoding activity of neutral, positive and negative words, while taking into account childhood abuse and psychiatric status. Our results show slightly lower hippocampal volumes in carriers of a met allele (n=54) relative to val/val homozygotes (n=103) (P=0.02, effect size (Cohen's d)=0.37), which appeared to be independent of childhood abuse and psychiatric status. For hippocampal encoding activity, we found a val(66)met-word valence interaction (P=0.02) such that carriers of a met allele showed increased levels of activation in response to negative words relative to activation in the neutral word condition and relative to val/val homozygotes. This, however, was only evident in the absence of childhood abuse, as abused val/val homozygotes showed hippocampal encoding activity for negative words that was comparable to that of carriers of a met allele. Neither psychiatric status nor memory accuracy did account for these associations. In conclusion, BDNF val(66)met has a significant impact on hippocampal volume independently of childhood abuse and psychiatric status. Furthermore, early adverse experiences such as childhood abuse account for individual differences in hippocampal encoding activity of negative stimuli but this effect manifests differently as a function of val(66)met. PMID:22832736

  18. Sleep in children triggers rapid reorganization of memory-related brain processes.

    PubMed

    Urbain, Charline; De Tiège, Xavier; Op De Beeck, Marc; Bourguignon, Mathieu; Wens, Vincent; Verheulpen, Denis; Van Bogaert, Patrick; Peigneux, Philippe

    2016-07-01

    Behavioral evidence shows that sleep is crucial for the consolidation of declarative memories in children as in adults. However, the underlying cerebral mechanisms remain virtually unexplored. Using magnetoencephalography, we investigated in children (8.0-12.5years) the impact of sleep (90-minute nap) on the neurophysiological processes underlying the creation and consolidation of novel associations between unknown objects and their functions. Learning-dependent changes in brain activity were observed within hippocampal and parahippocampal regions, followed by sleep-dependent changes in the prefrontal cortex, whereas no equivalent change was observed after a similar period of wakeful rest. Hence, our results show that in school-age children a 90-minute daytime nap after learning is sufficient to trigger the reorganization of memory-related brain activity toward prefrontal areas, where it incorporates into pre-existing semantic knowledge. This functional reorganization process in children is similar to that observed in adults but occurs at a much faster rate, which may contribute to the development of the impressive learning skills that characterize childhood. PMID:27039143

  19. The frequency of involuntary autobiographical memories and future thoughts in relation to daydreaming, emotional distress, and age.

    PubMed

    Berntsen, Dorthe; Rubin, David C; Salgado, Sinue

    2015-11-01

    We introduce a new scale, the Involuntary Autobiographical Memory Inventory (IAMI), for measuring the frequency of involuntary autobiographical memories and involuntary future thoughts. Using the scale in relation to other psychometric and demographic measures provided three important, novel findings. First, the frequency of involuntary and voluntary memories and future thoughts are similarly related to general measures of emotional distress. This challenges the idea that the involuntary mode is uniquely associated with emotional distress. Second, the frequency of involuntary autobiographical remembering does not decline with age, whereas measures of daydreaming, suppression of unwanted thoughts and dissociative experiences all do. Thus, involuntary autobiographical remembering relates differently to aging than daydreaming and other forms of spontaneous and uncontrollable thoughts. Third, unlike involuntary autobiographical remembering, the frequency of future thoughts does decrease with age. This finding underscores the need for examining past and future mental time travel in relation to aging and life span development. PMID:26241025

  20. The relation between fornix injury and memory impairment in patients with diffuse axonal injury: a diffusion tensor imaging study.

    PubMed

    Chang, Min Cheol; Kim, Seong Ho; Kim, Oh Lyong; Bai, Dai Seg; Jang, Sung Ho

    2010-01-01

    Little is known about the relation between fornix injury and memory impairment in diffuse axonal injury (DAI). In the current study, we attempted to investigate fornix injury in patients with memory impairment following DAI, using diffusion tensor imaging (DTI). Nine patients with DAI and nine age-and sex-matched control subjects were recruited. The DTIs were acquired using a sensitivity-encoding head coil on a 1.5 T. Five regions of interest (ROI) were drawn manually on a color fractional anisotropy (FA) map: two ROIs for each column, one ROI for the body, and two ROIs for each crus. The FA and apparent diffusion coefficient (ADC) were measured in each of the ROIs. Cognitive function was evaluated using the Memory Assessment Scale, Wechsler Intelligence Scale, and Mini-Mental State Exam. In the DAI group, the FA value in the fornix body was significantly decreased compared with that of the control group. In contrast, we did not find significant differences in the column and crus of the fornix. Among all of the cognitive function scales, only the Memory Assessment Scale scores were significantly correlated with the FA values of the fornix body in the DAI group. We found that memory impairment in patients with DAI is closely related to neuronal injury of the fornix body among the three fornix regions that we assessed. DTI could be useful in the evaluation of patients with memory impairment following DAI. PMID:20555158

  1. Age-related effects on spatial memory across viewpoint changes relative to different reference frames.

    PubMed

    Montefinese, Maria; Sulpizio, Valentina; Galati, Gaspare; Committeri, Giorgia

    2015-07-01

    Remembering object positions across different views is a fundamental competence for acting and moving appropriately in a large-scale space. Behavioural and neurological changes in elderly subjects suggest that the spatial representations of the environment might decline compared to young participants. However, no data are available on the use of different reference frames within topographical space in aging. Here we investigated the use of allocentric and egocentric frames in aging, by asking young and older participants to encode the location of a target in a virtual room relative either to stable features of the room (allocentric environment-based frame), or to an unstable objects set (allocentric objects-based frame), or to the viewer's viewpoint (egocentric frame). After a viewpoint change of 0° (absent), 45° (small) or 135° (large), participants judged whether the target was in the same spatial position as before relative to one of the three frames. Results revealed a different susceptibility to viewpoint changes in older than young participants. Importantly, we detected a worst performance, in terms of reaction times, for older than young participants in the allocentric frames. The deficit was more marked for the environment-based frame, for which a lower sensitivity was revealed as well as a worst performance even when no viewpoint change occurred. Our data provide new evidence of a greater vulnerability of the allocentric, in particular environment-based, spatial coding with aging, in line with the retrogenesis theory according to which cognitive changes in aging reverse the sequence of acquisition in mental development. PMID:25037856

  2. Cannabis-related episodic memory deficits and hippocampal morphological differences in healthy individuals and schizophrenia subjects.

    PubMed

    Smith, Matthew J; Cobia, Derin J; Reilly, James L; Gilman, Jodi M; Roberts, Andrea G; Alpert, Kathryn I; Wang, Lei; Breiter, Hans C; Csernansky, John G

    2015-09-01

    Cannabis use has been associated with episodic memory (EM) impairments and abnormal hippocampus morphology among both healthy individuals and schizophrenia subjects. Considering the hippocampus' role in EM, research is needed to evaluate the relationship between cannabis-related hippocampal morphology and EM among healthy and clinical groups. We examined differences in hippocampus morphology between control and schizophrenia subjects with and without a past (not current) cannabis use disorder (CUD). Subjects group-matched on demographics included 44 healthy controls (CON), 10 subjects with a CUD history (CON-CUD), 28 schizophrenia subjects with no history of substance use disorders (SCZ), and 15 schizophrenia subjects with a CUD history (SCZ-CUD). Large-deformation, high-dimensional brain mapping with MRI produced surface-based representations of the hippocampus that were compared across all four groups and correlated with EM and CUD history. Surface maps of the hippocampus were generated to visualize morphological differences. CON-CUD and SCZ-CUD were characterized by distinct cannabis-related hippocampal shape differences and parametric deficits in EM performance. Shape differences observed in CON-CUD were associated with poorer EM performance, while shape differences observed in SCZ-CUD were associated with a longer duration of CUD and shorter duration of CUD remission. A past history of CUD may be associated with notable differences in hippocampal morphology and EM impairments among adults with and without schizophrenia. Although the results may be compatible with a causal hypothesis, we must consider that the observed cannabis-related shape differences in the hippocampus could also be explained as biomarkers of a neurobiological susceptibility to poor memory or the effects of cannabis. PMID:25760303

  3. Why Distinctive Information Reduces False Memories: Evidence for Both Impoverished Relational-Encoding and Distinctiveness Heuristic Accounts

    ERIC Educational Resources Information Center

    Hege, Amanda C. G.; Dodson, Chad S.

    2004-01-01

    Two accounts explain why studying pictures reduces false memories within the Deese-Roediger-McDermott paradigm (J. Deese, 1959; H. L. Roediger & K. B. McDermott, 1995). The impoverished relational-encoding account suggests that studying pictures interferes with the encoding of relational information, which is the primary basis for false memories…

  4. When Does Memory Monitoring Succeed versus Fail? Comparing Item-Specific and Relational Encoding in the DRM Paradigm

    ERIC Educational Resources Information Center

    Huff, Mark J.; Bodner, Glen E.

    2013-01-01

    We compared the effects of item-specific versus relational encoding on recognition memory in the Deese-Roediger-McDermott paradigm. In Experiment 1, we directly compared item-specific and relational encoding instructions, whereas in Experiments 2 and 3 we biased pleasantness and generation tasks, respectively, toward one or the other type of…

  5. Differences in Induced Brain Activity during the Performance of Learning and Working-Memory Tasks Related to Intelligence

    ERIC Educational Resources Information Center

    Jausovec, Norbert; Jausovec, Ksenija

    2004-01-01

    Thirteen high intelligent (H-IQ) and 13 low intelligent (L-IQ) individuals solved two figural working-memory (WM) tasks and two figural learning tasks while their EEG was recorded. For the WM tasks, only in the theta band group related differences in induced event-related desynchronization/synchronization (ERD/ERS) were observed. L-IQ individuals…

  6. Kindergarten letter knowledge, phonological skills, and memory processes: relative effects on early literacy.

    PubMed

    Näslund, J C; Schneider, W

    1996-06-01

    Kindergarten phonological awareness tasks are first compared as to their predictability of later literacy performance independent of letter knowledge for a group of German children. Results indicate that the phonological awareness tasks vary in their prediction of later literacy performance, which includes spelling and a variety of reading tasks in the first and second grades. A second concern was the relative influence of kindergarten phonological awareness compared with letter knowledge in the prediction of later literacy. The primacy of phonological awareness was demonstrated in predicting later literacy. However, evidence indicated that high letter knowledge in kindergarten may also reliably predict better later literacy skills. Results also suggest a developmental effect in the emergence of phonological processing skills in verbal memory between the ages of 4 and 8. Results of this study differ from those found in other (English speaking) populations most likely given differences in early literacy knowledge, age of beginning reading instruction, and differences in German and English orthography. PMID:8683184

  7. Age-related decline in verbal learning is moderated by demographic factors, working memory capacity, and presence of amnestic mild cognitive impairment.

    PubMed

    Constantinidou, Fofi; Zaganas, Ioannis; Papastefanakis, Emmanouil; Kasselimis, Dimitrios; Nidos, Andreas; Simos, Panagiotis G

    2014-09-01

    Age-related memory changes are highly varied and heterogeneous. The study examined the rate of decline in verbal episodic memory as a function of education level, auditory attention span and verbal working memory capacity, and diagnosis of amnestic mild cognitive impairment (a-MCI). Data were available on a community sample of 653 adults aged 17-86 years and 70 patients with a-MCI recruited from eight broad geographic areas in Greece and Cyprus. Measures of auditory attention span and working memory capacity (digits forward and backward) and verbal episodic memory (Auditory Verbal Learning Test [AVLT]) were used. Moderated mediation regressions on data from the community sample did not reveal significant effects of education level on the rate of age-related decline in AVLT indices. The presence of a-MCI was a significant moderator of the direct effect of Age on both immediate and delayed episodic memory indices. The rate of age-related decline in verbal episodic memory is normally mediated by working memory capacity. Moreover, in persons who display poor episodic memory capacity (a-MCI group), age-related memory decline is expected to advance more rapidly for those who also display relatively poor verbal working memory capacity. PMID:25156204

  8. The relation between receptive grammar and procedural, declarative, and working memory in specific language impairment

    PubMed Central

    Conti-Ramsden, Gina; Ullman, Michael T.; Lum, Jarrad A. G.

    2015-01-01

    What memory systems underlie grammar in children, and do these differ between typically developing (TD) children and children with specific language impairment (SLI)? Whilst there is substantial evidence linking certain memory deficits to the language problems in children with SLI, few studies have investigated multiple memory systems simultaneously, examining not only possible memory deficits but also memory abilities that may play a compensatory role. This study examined the extent to which procedural, declarative, and working memory abilities predict receptive grammar in 45 primary school aged children with SLI (30 males, 15 females) and 46 TD children (30 males, 16 females), both on average 9;10 years of age. Regression analyses probed measures of all three memory systems simultaneously as potential predictors of receptive grammar. The model was significant, explaining 51.6% of the variance. There was a significant main effect of learning in procedural memory and a significant group × procedural learning interaction. Further investigation of the interaction revealed that procedural learning predicted grammar in TD but not in children with SLI. Indeed, procedural learning was the only predictor of grammar in TD. In contrast, only learning in declarative memory significantly predicted grammar in SLI. Thus, different memory systems are associated with receptive grammar abilities in children with SLI and their TD peers. This study is, to our knowledge, the first to demonstrate a significant group by memory system interaction in predicting grammar in children with SLI and their TD peers. In line with Ullman’s Declarative/Procedural model of language and procedural deficit hypothesis of SLI, variability in understanding sentences of varying grammatical complexity appears to be associated with variability in procedural memory abilities in TD children, but with declarative memory, as an apparent compensatory mechanism, in children with SLI. PMID:26284013

  9. Attention and Working Memory-Related EEG Markers of Subtle Cognitive Deterioration in Healthy Elderly Individuals.

    PubMed

    Deiber, Marie-Pierre; Meziane, Hadj Boumediene; Hasler, Roland; Rodriguez, Cristelle; Toma, Simona; Ackermann, Marine; Herrmann, François; Giannakopoulos, Panteleimon

    2015-01-01

    Future treatments of Alzheimer's disease need the identification of cases at high risk at the preclinical stage of the disease before the development of irreversible structural damage. We investigated here whether subtle cognitive deterioration in a population of healthy elderly individuals could be predicted by EEG signals at baseline under cognitive activation. Continuous EEG was recorded in 97 elderly control subjects and 45 age-matched mild cognitive impairment (MCI) cases during a simple attentional and a 2-back working memory task. Upon 18-month neuropsychological follow-up, the final sample included 55 stable (sCON) and 42 deteriorated (dCON) controls. We examined the P1, N1, P3, and PNwm event-related components as well as the oscillatory activities in the theta (4-7 Hz), alpha (8-13 Hz), and beta (14-25 Hz) frequency ranges (ERD/ERS: event-related desynchronization/synchronization, and ITC: inter-trial coherence). Behavioral performance, P1, and N1 components were comparable in all groups. The P3, PNwm, and all oscillatory activity indices were altered in MCI cases compared to controls. Only three EEG indices distinguished the two control groups: alpha and beta ERD (dCON >  sCON) and beta ITC (dCON <  sCON). These findings show that subtle cognitive deterioration has no impact on EEG indices associated with perception, discrimination, and working memory processes but mostly affects attention, resulting in an enhanced recruitment of attentional resources. In addition, cognitive decline alters neural firing synchronization at high frequencies (14-25 Hz) at early stages, and possibly affects lower frequencies (4-13 Hz) only at more severe stages. PMID:26401557

  10. α Power Modulation and Event-Related Slow Wave Provide Dissociable Correlates of Visual Working Memory

    PubMed Central

    Mance, Irida; Vogel, Edward K.

    2015-01-01

    Traditionally, electrophysiological correlates of visual working memory (VWM) capacity have been characterized using a lateralized VWM task in which participants had to remember items presented on the cued hemifield while ignoring the distractors presented on the other hemifield. Though this approach revealed a lateralized parieto-occipital negative slow wave (i.e., the contralateral delay activity) and lateralized α power modulation as neural correlates of VWM capacity that may be mechanistically related, recent evidence suggested that these measures might be reflecting individuals' ability to ignore distractors rather than their ability to maintain VWM representations. To better characterize the neural correlates of VWM capacity, we had human participants perform a whole-field VWM task in which they remembered all the items on the display. Here, we found that both the parieto-occipital negative slow wave and the α power suppression showed the characteristics of VWM capacity in the absence of distractors, suggesting that they reflect the maintenance of VWM representations rather than filtering of distractors. Furthermore, the two signals explained unique portions of variance in individual differences of VWM capacity and showed differential temporal characteristics. This pattern of results clearly suggests that individual differences in VWM capacity are determined by dissociable neural mechanisms reflected in the ERP and the oscillatory measures of VWM capacity. SIGNIFICANCE STATEMENT Our work demonstrates that there exist event-related potential and oscillatory correlates of visual working memory (VWM) capacity even in the absence of task-irrelevant distractors. This clearly shows that the two neural correlates are directly linked to maintenance of task-relevant information rather than filtering of task-irrelevant information. Furthermore, we found that these two correlates show differential temporal characteristics. These results are inconsistent with proposals

  11. Cognitive memory.

    PubMed

    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

  12. Event-related brain potentials that distinguish false memory for events that occurred only seconds in the past

    PubMed Central

    2012-01-01

    Background False memory often involves retrieving events from the distant past that did not actually happen. However, recent evidence obtained using the Deese/Roediger-McDermott (DRM) paradigm for eliciting false memory experiences suggests that individuals can falsely believe that events occurred mere seconds in the past when they in fact did not. Subjects in these experiments endorsed unstudied critical lure words as having been studied, despite the fact that word lists were studied just moments before. We identified event-related brain potential (ERP) correlates of this experience, and included a repetition priming manipulation to better assess the functional significance of these ERPs. Methods Behavioral and ERP data were collected from 21 Capital Normal University students using a short-term DRM task. Results Two categories of effects were identified that distinguished true from false short-term memory: (1) early semantic priming effects from 300 to 500 ms and (2) later retrieval and retrieval-monitoring effects after 500 ms. The repetition priming manipulation had distinct influences on these effects, consistent with their differential associations with semantic priming versus episodic retrieval. Conclusion Characterization of ERPs related to semantic priming and episodic retrieval provides important information regarding the mechanisms of short-term false memory. In contrast, most studies examining false memory in standard long-delay DRM paradigms identify ERP effects related only to retrieval monitoring. These findings highlight the neural processing involved in illusions of memory after very brief delays and highlight the role of semantic processing in short-term false memory. PMID:22846189

  13. The Inaugural Elijah B. Saunders Memorial Lecture: The Global Consequences of Hypertension and Related Disparities.

    PubMed

    Mensah, George A

    2016-01-01

    This inaugural memorial lecture provides an opportunity to celebrate the life of Elijah B. Saunders, MD, FACC and pays tribute to his pioneering spirit in the quest to advance health equity in the prevention and control of hypertension and cardiovascular diseases. It also enables an assessment of the state of the global burden of hypertension and related disparities. Despite the remarkable biomedical research progress made over the last half-century, hypertension remains the leading risk factor for global disease burden and the major preventable contributor to cardiovascular and all-cause mortality. Additionally, disparities in hypertension-related morbidity and mortality remain pervasive worldwide. National hypertension control rates showing progress often mask important suboptimal treatment and control in population groups defined by sex, race, ethnicity, geography, and social and environmental determinants. Within these groups, many hypertension-related disparities remain largely unchanged while other gaps have widened. In essence, current research has been relatively ineffective in guiding large-scale, sustained elimination of hypertension-related disparities. An important explanation for these observations may be the significant advances made in observational epidemiological research, especially in improved surveillance and data collection that document the extent of disparities in marked contrast to the relative paucity of interventional disparities research. The paucity of these interventional research studies remains a continuing challenge. The time has come for renewed efforts in building strategic partnerships that leverage transdisciplinary, multi-sectoral expertise to provide global leadership in interventional implementation research for hypertension control and elimination of related disparities. Developing an appropriately skilled implementation research workforce will be crucial. The National Heart, Lung, and Blood Institute and its biomedical

  14. Maintenance of relational information in working memory leads to suppression of the sensory cortex

    PubMed Central

    Ikkai, Akiko; Blacker, Kara J.; Lakshmanan, Balaji M.; Ewen, Joshua B.

    2014-01-01

    Working memory (WM) for sensory-based information about individual objects and their locations appears to involve interactions between lateral prefrontal and sensory cortexes. The mechanisms and representations for maintenance of more abstract, nonsensory information in WM are unknown, particularly whether such actively maintained information can become independent of the sensory information from which it was derived. Previous studies of WM for individual visual items found increased electroencephalogram (EEG) alpha (8–13 Hz) power over posterior electrode sites, which appears to correspond to the suppression of cortical areas that represent irrelevant sensory information. Here, we recorded EEG while participants performed a visual WM task that involved maintaining either concrete spatial coordinates or abstract relational information. Maintenance of relational information resulted in higher alpha power in posterior electrodes. Furthermore, lateralization of alpha power due to a covert shift of attention to one visual hemifield was marginally weaker during storage of relational information than during storage of concrete information. These results suggest that abstract relational information is maintained in WM differently from concrete, sensory representations and that during maintenance of abstract information, posterior sensory regions become task irrelevant and are thus suppressed. PMID:25031260

  15. How Linguistic Closure and Verbal Working Memory Relate to Speech Recognition in Noise—A Review

    PubMed Central

    Koelewijn, Thomas; Zekveld, Adriana A.; Kramer, Sophia E.; Festen, Joost M.

    2013-01-01

    The ability to recognize masked speech, commonly measured with a speech reception threshold (SRT) test, is associated with cognitive processing abilities. Two cognitive factors frequently assessed in speech recognition research are the capacity of working memory (WM), measured by means of a reading span (Rspan) or listening span (Lspan) test, and the ability to read masked text (linguistic closure), measured by the text reception threshold (TRT). The current article provides a review of recent hearing research that examined the relationship of TRT and WM span to SRTs in various maskers. Furthermore, modality differences in WM capacity assessed with the Rspan compared to the Lspan test were examined and related to speech recognition abilities in an experimental study with young adults with normal hearing (NH). Span scores were strongly associated with each other, but were higher in the auditory modality. The results of the reviewed studies suggest that TRT and WM span are related to each other, but differ in their relationships with SRT performance. In NH adults of middle age or older, both TRT and Rspan were associated with SRTs in speech maskers, whereas TRT better predicted speech recognition in fluctuating nonspeech maskers. The associations with SRTs in steady-state noise were inconclusive for both measures. WM span was positively related to benefit from contextual information in speech recognition, but better TRTs related to less interference from unrelated cues. Data for individuals with impaired hearing are limited, but larger WM span seems to give a general advantage in various listening situations. PMID:23945955

  16. Resveratrol Prevents Age-Related Memory and Mood Dysfunction with Increased Hippocampal Neurogenesis and Microvasculature, and Reduced Glial Activation

    PubMed Central

    Kodali, Maheedhar; Parihar, Vipan K.; Hattiangady, Bharathi; Mishra, Vikas; Shuai, Bing; Shetty, Ashok K.

    2015-01-01

    Greatly waned neurogenesis, diminished microvasculature, astrocyte hypertrophy and activated microglia are among the most conspicuous structural changes in the aged hippocampus. Because these alterations can contribute to age-related memory and mood impairments, strategies efficacious for mitigating these changes may preserve cognitive and mood function in old age. Resveratrol, a phytoalexin found in the skin of red grapes having angiogenic and antiinflammatory properties, appears ideal for easing these age-related changes. Hence, we examined the efficacy of resveratrol for counteracting age-related memory and mood impairments and the associated detrimental changes in the hippocampus. Two groups of male F344 rats in late middle-age having similar learning and memory abilities were chosen and treated with resveratrol or vehicle for four weeks. Analyses at ~25 months of age uncovered improved learning, memory and mood function in resveratrol-treated animals but impairments in vehicle-treated animals. Resveratrol-treated animals also displayed increased net neurogenesis and microvasculature, and diminished astrocyte hypertrophy and microglial activation in the hippocampus. These results provide novel evidence that resveratrol treatment in late middle age is efficacious for improving memory and mood function in old age. Modulation of the hippocampus plasticity and suppression of chronic low-level inflammation appear to underlie the functional benefits mediated by resveratrol. PMID:25627672

  17. Chronic pubertal, but not adult chronic cannabinoid treatment impairs sensorimotor gating, recognition memory, and the performance in a progressive ratio task in adult rats.

    PubMed

    Schneider, Miriam; Koch, Michael

    2003-10-01

    There is evidence from studies in humans and animals that a vulnerable period for chronic cannabinoid administration exists during certain phases of development. The present study tested the hypothesis that long-lasting interference of cannabinoids with the developing endogenous cannabinoid system during puberty causes persistent behavioral alterations in adult rats. Chronic treatment with the synthetic cannabinoid agonist WIN 55,212-2 (WIN) (1.2 mg/kg) or vehicle was extended over 25 days either throughout the rats' puberty or for a similar time period in adult rats. The rats received 20 injections intraperitoneally (i.p.), which were not delivered regularly. Adult rats were tested for object recognition memory, performance in a progressive ratio (PR) operant behavior task, locomotor activity, and prepulse inhibition (PPI) of the acoustic startle response (ASR). PPI was significantly disrupted only by chronic peripubertal cannabinoid treatment. This long-lasting PPI deficit was reversed by the acute administration of the dopamine antagonist haloperidol. Furthermore, we found deficits in recognition memory of pubertal-treated rats and these animals showed lower break points in a PR schedule, whereas food preference and locomotion were not affected. Adult chronic cannabinoid treatment had no effect on the behaviors tested. Therefore, we conclude that puberty in rats is a vulnerable period with respect to the adverse effects of cannabinoid treatment. Since PPI deficits, object recognition memory impairments, and anhedonia/avolition are among the endophenotypes of schizophrenia, we propose chronic cannabinoid administration during pubertal development as an animal model for some aspects of the etiology of schizophrenia. PMID:12888772

  18. Newly-formed emotional memories guide selective attention processes: Evidence from event-related potentials.

    PubMed

    Schupp, Harald T; Kirmse, Ursula; Schmälzle, Ralf; Flaisch, Tobias; Renner, Britta

    2016-01-01

    Emotional cues can guide selective attention processes. However, emotional stimuli can both activate long-term memory representations reflecting general world knowledge and engage newly formed memory representations representing specific knowledge from the immediate past. Here, the self-completion feature of associative memory was utilized to assess the regulation of attention processes by newly-formed emotional memory. First, new memory representations were formed by presenting pictures depicting a person either in an erotic pose or as a portrait. Afterwards, to activate newly-built memory traces, edited pictures were presented showing only the head region of the person. ERP recordings revealed the emotional regulation of attention by newly-formed memories. Specifically, edited pictures from the erotic compared to the portrait category elicited an early posterior negativity and late positive potential, similar to the findings observed for the original pictures. A control condition showed that the effect was dependent on newly-formed memory traces. Given the large number of new memories formed each day, they presumably make an important contribution to the regulation of attention in everyday life. PMID:27321471

  19. Quantum memory effects in disordered systems and their relation to 1 /f noise

    NASA Astrophysics Data System (ADS)

    Lemonik, Yonah; Aleiner, Igor

    2014-11-01

    We propose that memory effects in the conductivity of metallic systems can be produced by the same two-level systems that are responsible for the 1 /f noise. Memory effects are extremely long-lived responses of the conductivity to changes in external parameters such as density or magnetic field. Using quantum transport theory, we derive a universal relationship between the memory effect and the 1 /f noise. Finally, we propose a magnetic memory effect, where the magnetoresistance is sensitive to the history of the applied magnetic field.

  20. Newly-formed emotional memories guide selective attention processes: Evidence from event-related potentials

    PubMed Central

    Schupp, Harald T.; Kirmse, Ursula; Schmälzle, Ralf; Flaisch, Tobias; Renner, Britta

    2016-01-01

    Emotional cues can guide selective attention processes. However, emotional stimuli can both activate long-term memory representations reflecting general world knowledge and engage newly formed memory representations representing specific knowledge from the immediate past. Here, the self-completion feature of associative memory was utilized to assess the regulation of attention processes by newly-formed emotional memory. First, new memory representations were formed by presenting pictures depicting a person either in an erotic pose or as a portrait. Afterwards, to activate newly-built memory traces, edited pictures were presented showing only the head region of the person. ERP recordings revealed the emotional regulation of attention by newly-formed memories. Specifically, edited pictures from the erotic compared to the portrait category elicited an early posterior negativity and late positive potential, similar to the findings observed for the original pictures. A control condition showed that the effect was dependent on newly-formed memory traces. Given the large number of new memories formed each day, they presumably make an important contribution to the regulation of attention in everyday life. PMID:27321471

  1. The Impact of NMDA Receptor Blockade on Human Working Memory-Related Prefrontal Function and Connectivity

    PubMed Central

    Driesen, Naomi R; McCarthy, Gregory; Bhagwagar, Zubin; Bloch, Michael H; Calhoun, Vincent D; D'Souza, Deepak C; Gueorguieva, Ralitza; He, George; Leung, Hoi-Chung; Ramani, Ramachandran; Anticevic, Alan; Suckow, Raymond F; Morgan, Peter T; Krystal, John H

    2013-01-01

    Preclinical research suggests that N-methyl-D-aspartate glutamate receptors (NMDA-Rs) have a crucial role in working memory (WM). In this study, we investigated the role of NMDA-Rs in the brain activation and connectivity that subserve WM. Because of its importance in WM, the lateral prefrontal cortex, particularly the dorsolateral prefrontal cortex and its connections, were the focus of analyses. Healthy participants (n=22) participated in a single functional magnetic resonance imaging session. They received saline and then the NMDA-R antagonist ketamine while performing a spatial WM task. Time-course analysis was used to compare lateral prefrontal activation during saline and ketamine administration. Seed-based functional connectivity analysis was used to compare dorsolateral prefrontal connectivity during the two conditions and global-based connectivity was used to test for laterality in these effects. Ketamine reduced accuracy on the spatial WM task and brain activation during the encoding and early maintenance (EEM) period of task trials. Decrements in task-related activation during EEM were related to performance deficits. Ketamine reduced connectivity in the DPFC network bilaterally, and region-specific reductions in connectivity were related to performance. These results support the hypothesis that NMDA-Rs are critical for WM. The knowledge gained may be helpful in understanding disorders that might involve glutamatergic deficits such as schizophrenia and developing better treatments. PMID:23856634

  2. Age-related effects on perceptual and semantic encoding in memory.

    PubMed

    Kuo, M C C; Liu, K P Y; Ting, K H; Chan, C C H

    2014-03-01

    This study examined the age-related subsequent memory effect (SME) in perceptual and semantic encoding using event-related potentials (ERPs). Seventeen younger adults and 17 older adults studied a series of Chinese characters either perceptually (by inspecting orthographic components) or semantically (by determining whether the depicted object makes sounds). The two tasks had similar levels of difficulty. The participants made studied or unstudied judgments during the recognition phase. Younger adults performed better in both conditions, with significant SMEs detected in the time windows of P2, N3, P550, and late positive component (LPC). In the older group, SMEs were observed in the P2 and N3 latencies in both conditions but were only detected in the P550 in the semantic condition. Between-group analyses showed larger frontal and central SMEs in the younger sample in the LPC latency regardless of encoding type. Aging effect appears to be stronger on influencing perceptual than semantic encoding processes. The effects seem to be associated with a decline in updating and maintaining representations during perceptual encoding. The age-related decline in the encoding function may be due in part to changes in frontal lobe function. PMID:24374080

  3. Parallel Working Memory for Spatial Location and Food-Related Object Cues in Foraging Pigeons: Binocular and Lateralized Monocular Performance

    PubMed Central

    Prior, Helmut; Güntürkün, Onur

    2001-01-01

    During foraging, animals can increase their success by both remembering feeding sites and remembering food-related object cues. Because earlier studies have tested either the site or object memory in isolation, the aim of the present study was to evaluate how efficiently birds can utilize both memories simultaneously. Furthermore, the idea was tested that lateralization might be the principle of brain organization that allows for efficient parallel processing. Pigeons learned to search for food in a complex maze with 16 baited sites. To obtain the maximum reward they had to perform two tasks in parallel, a spatial working memory task and an object-specific working memory task. Birds performed well on this dual task but, compared with spatial working memory alone, they were impaired during the first choices of a trial (Experiment 1). When the left and the right brain hemispheres were tested separately by means of monocular occlusion (Experiment 2), object discrimination was better when birds used their right eye/left hemisphere. This was most pronounced during the first choices of a trial. On the spatial component of the task, performance on binocular trials was better than on monocular trials, but monocularly both hemispheres performed at the same level. Results show that on this dual task, discrimination of food-related object cues predominantly involved the left brain hemisphere whereas both hemispheres contributed equally to spatial performance. PMID:11160763

  4. Persistent neural activity in auditory cortex is related to auditory working memory in humans and nonhuman primates

    PubMed Central

    Huang, Ying; Matysiak, Artur; Heil, Peter; König, Reinhard; Brosch, Michael

    2016-01-01

    Working memory is the cognitive capacity of short-term storage of information for goal-directed behaviors. Where and how this capacity is implemented in the brain are unresolved questions. We show that auditory cortex stores information by persistent changes of neural activity. We separated activity related to working memory from activity related to other mental processes by having humans and monkeys perform different tasks with varying working memory demands on the same sound sequences. Working memory was reflected in the spiking activity of individual neurons in auditory cortex and in the activity of neuronal populations, that is, in local field potentials and magnetic fields. Our results provide direct support for the idea that temporary storage of information recruits the same brain areas that also process the information. Because similar activity was observed in the two species, the cellular bases of some auditory working memory processes in humans can be studied in monkeys. DOI: http://dx.doi.org/10.7554/eLife.15441.001 PMID:27438411

  5. Working Memory in Unaffected Relatives of Patients With Schizophrenia: A Meta-Analysis of Functional Magnetic Resonance Imaging Studies.

    PubMed

    Zhang, Ruibin; Picchioni, Marco; Allen, Paul; Toulopoulou, Timothea

    2016-07-01

    Working memory deficits, a core cognitive feature of schizophrenia may arise from dysfunction in the frontal and parietal cortices. Numerous studies have also found abnormal neural activation during working memory tasks in patients' unaffected relatives. The aim of this study was to systematically identify and anatomically localize the evidence for those activation differences across all eligible studies. Fifteen functional magnetic resonance imaging (fMRI) manuscripts, containing 16 samples of 289 unaffected relatives of patients with schizophrenia, and 358 healthy controls were identified that met our inclusion criteria: (1) used a working memory task; and (2) reported standard space coordinates. Activation likelihood estimation (ALE) identified convergence across studies. Compared to healthy controls, patients' unaffected relatives showed decreases in neural activation in the right middle frontal gyrus (BA9), as well as right inferior frontal gyrus (BA44). Increased activation was seen in relatives in the right frontopolar (BA10), left inferior parietal lobe (BA40), and thalamus bilaterally. These results suggest that the familial risk of schizophrenia is expressed in changes in neural activation in the unaffected relatives in the cortical-subcortical working memory network that includes, but is not restricted to the middle prefrontal cortex. PMID:26738528

  6. An Event Related Potentials Study of the Effects of Age, Load and Maintenance Duration on Working Memory Recognition

    PubMed Central

    Pinal, Diego; Zurrón, Montserrat; Díaz, Fernando

    2015-01-01

    Age-related decline in cognitive capacities has been attributed to a generalized slowing of processing speed and a reduction in working memory (WM) capacity. Nevertheless, it is unclear how age affects visuospatial WM recognition and its underlying brain electrical activity. Whether age modulates the effects of memory load or information maintenance duration, which determine the limits of WM, remains also elusive. In this exploratory study, performance in a delayed match to sample task declined with age, particularly in conditions with high memory load. Event related potentials analysis revealed longer N2 and P300 latencies in old than in young adults during WM recognition, which may reflect slowing of stimulus evaluation and classification processes, respectively. Although there were no differences between groups in N2 or P300 amplitudes, the latter was more homogeneously distributed in old than in young adults, which may indicate an age-related increased reliance in frontal vs parietal resources during WM recognition. This was further supported by an age-related reduced posterior cingulate activation and increased superior frontal gyrus activation revealed through standardized low resolution electromagnetic tomography. Memory load and maintenance duration effects on brain activity were similar in both age groups. These behavioral and electrophysiological results add evidence in support of age-related decline in WM recognition theories, with a slowing of processing speed that may be limited to stimulus evaluation and categorization processes -with no effects on perceptual processes- and a posterior to anterior shift in the recruitment of neural resources. PMID:26569113

  7. Semantic False Memories in the Form of Derived Relational Intrusions Following Training

    ERIC Educational Resources Information Center

    Guinther, Paul M.; Dougher, Michael J.

    2010-01-01

    Contemporary behavior analytic research is making headway in characterizing memory phenomena that typically have been characterized by cognitive models, and the current study extends this development by producing "false memories" in the form of functional equivalence responding. A match-to-sample training procedure was administered in order to…

  8. The Relation between Navigation Strategy and Associative Memory: An Individual Differences Approach

    ERIC Educational Resources Information Center

    Ngo, Chi T.; Weisberg, Steven M.; Newcombe, Nora S.; Olson, Ingrid R.

    2016-01-01

    Although the hippocampus is implicated in both spatial navigation and associative memory, very little is known about whether individual differences in the 2 domains covary. People who prefer to navigate using a hippocampal-dependent place strategy may show better performance on associative memory tasks than those who prefer a caudate-dependent…

  9. Improvement in Working Memory Is Not Related to Increased Intelligence Scores

    ERIC Educational Resources Information Center

    Colom, Roberto; Quiroga, Ma. Angeles; Shih, Pei Chun; Martinez, Kenia; Burgaleta, Miguel; Martinez-Molina, Agustin; Roman, Francisco J.; Requena, Laura; Ramirez, Isabel

    2010-01-01

    The acknowledged high relationship between working memory and intelligence suggests common underlying cognitive mechanisms and, perhaps, shared biological substrates. If this is the case, improvement in working memory by repeated exposure to challenging span tasks might be reflected in increased intelligence scores. Here we report a study in which…

  10. Mechanisms of Memory.

    ERIC Educational Resources Information Center

    Squire, Larry R.

    1986-01-01

    Focuses on the brain processes and brain systems involved in learning and memory from a neuropsychological perspective of analysis. Reports findings related to the locus of memory storage, types of memory and knowledge, and memory consolidation. Models of animal memory are also examined. An extensive reference list is included. (ML)

  11. Network dynamics mediated by heterogeneous topology as related to hippocampal memory management

    NASA Astrophysics Data System (ADS)

    Wang, Jane; Poe, Gina; Zochowski, Michal

    2009-03-01

    Hippocampal-cortical network interactions, including reactivation of recently acquired memories in the hippocampus during sleep, are key to the consolidation of memory traces to long-term storage sites in the neocortex. Network heterogeneities, in the form of regional changes in the connectivity densities of excitatory synapses, support this process in simulated hippocampal-cortical networks by regulating intrinsic network dynamics and thus mediating stimulus familiarity detection as well as selective memory consolidation. We characterize this network model by investigating dynamics due to distributed and overlapping memory structures and examine the ability of regional heterogeneities to both selectively activate in the presence of controlled stimuli and reactivate in the absence of stimuli, the former being indicative of active exploration and the latter of memory replay during sleep.

  12. Episodic future thinking: the role of working memory and inhibition on age-related differences.

    PubMed

    Zavagnin, Michela; De Beni, Rossana; Borella, Erika; Carretti, Barbara

    2016-02-01

    The ability to remember past events and imagine future events (episodic future thinking-EFT) has been shown to decline with aging. However, only few studies have analyzed the cognitive mechanisms involved in EFT in both young and older adults. The present study examined the role of working memory and inhibition on age-related differences between young and older adults in EFT, in response to short sentences reflecting common events, some of which were repeated in both conditions (past and future). Thirty-seven young and 36 older adults completed an adapted version of the autobiographical interview, in which sentences were presented. Results showed that processing resources explained a significant part of the variance in the amount of details; in particular, inhibition explained the amount of external details produced in the future condition. In addition, using sentences, the older group did not differ from the young adults in terms of the proportion of internal details recalled in the past condition, whereas they produced a lower proportion of internal details in the future condition. The effect of using structured material was reinforced by repeating some sentences in the past. Further, only older adults rated the remembered episodes as more emotionally salient and relevant than the imagined ones. Age-related differences between young and older adults in EFT appear to depend on the type of material used, on basic mechanisms of cognition, and are characterized by both quantitative and qualitative differences. PMID:25963665

  13. Quantification of event-related desynchronization/synchronization at low frequencies in a semantic memory task.

    PubMed

    Gómez, Juan; Aguilar, Mónica; Horna, Eduardo; Minguez, Javier

    2012-01-01

    Although several techniques have been developed for the visualization of EEG event-related desynchronization/synchronization (ERD/ERS) in both time and frequency domains, none of the quantification methods takes advantage of the time and frequency resolution at the same time. Existing techniques for the quantification of the ERD/ERS changes compute the average EEG power increase/decrease relative to certain reference value, over fixed time intervals and/or frequency bands (either fixed or individualized). Inaccuracy in the computation of these frequency bands (where the process is actually measured) in combination with the averaging process over time may lead to errors in the computation of any ERD/ERS quantification parameter. In this paper, we present a novel method for the automatic, individual and exact quantification of the most significant ERD/ERS region within a given window of the time-frequency domain. The method is exemplified by quantifying the ERS at low frequencies of 10 subjects performing a semantic memory task, and compared with existing techniques. PMID:23366438

  14. Maternal inflammation linearly exacerbates offspring age-related changes of spatial learning and memory, and neurobiology until senectitude.

    PubMed

    Li, Xue-Wei; Cao, Lei; Wang, Fang; Yang, Qi-Gang; Tong, Jing-Jing; Li, Xue-Yan; Chen, Gui-Hai

    2016-06-01

    Maternal inflammation during pregnancy can elevate the risk of neurodegenerative disorders in offspring. However, how it affects age-related impairments of spatial learning and memory and changes in the neurobiological indictors in the offspring in later adulthood is still elusive. In this study, the CD-1 mice with maternal gestational inflammation due to receiving lipopolysaccharide (LPS, i.p. 50 or 25μg/kg) were divided into 3-, 12-, 18-, and 22-month-old groups. The spatial learning and memory were evaluated using a six-radial arm water maze and the levels of presynaptic proteins (synaptotagmin-1 and syntaxin-1) and histone acetylation (H3K9ac and H4K8ac) in the dorsal hippocampus were detected using the immunohistochemical method. The results indicated that there were significant age-related impairments of spatial learning and memory, decreased levels of H4K8ac, H3K9ac, and syntaxin-1, and increased levels of synaptotagmin-1 in the offspring mice from 12 months old to 22 months old compared to the same-age controls. Maternal LPS treatment significantly exacerbated the offspring impairments of spatial learning and memory, the reduction of H3K9ac, H4K8ac, and syntaxin-1, and the increment of synaptotagmin-1 from 12 months old to 22 months old compared to the same-age control groups. The changes in the neurobiological indicators significantly correlated with the impairments of spatial learning and memory. Furthermore, this correlation, besides the age and LPS-treatment effects, also showed a dose-dependent effect. Our results suggest that maternal inflammation during pregnancy could exacerbate age-related impairments of spatial learning and memory, and neurobiochemical indicators in the offspring CD-1 mice from midlife to senectitude. PMID:26992827

  15. Voltage-gated potassium channel antibody-related encephalopathy: a case which may extend the documented phenotype of this condition

    PubMed Central

    Scott, Janet T; Scally, Caroline; Peden, Norman; Macleod, Malcolm

    2012-01-01

    A 51-year-old man presented with a focal epileptic, fluctuating encephalopathy. Antibodies to voltage-gated potassium channels (VGKC-Abs) were detected in his serum. Several features of this case were different from those previously reported in VGKC-Ab-associated encephalitis, illustrating that it may have a broader phenotype than previously documented. These features were: excess hepatic iron deposits without cirrhosis, reduced consciousness and fluctuating neurological signs. Previous history included personality change, depression, type 2 diabetes mellitus, pupil sparing third nerve palsy and epilepsy secondary to a head injury. He had never drunk alcohol and had recovered from a similar episode 4 years previously. Both episodes resolved after approximately 2 months. The cerebrospinal fluid had a raised protein content but no organisms. The patient was heterozygous for C282Y and negative for H63D mutations excluding classical idiopathic haemochromatosis. He recovered with supportive care to his premorbid level of health. PMID:22693327

  16. The role of memories on health-related quality of life after intensive care unit care: an unforgettable controversy?

    PubMed Central

    Orwelius, Lotti; Teixeira-Pinto, Armando; Lobo, Cristina; Costa-Pereira, Altamiro; Granja, Cristina

    2016-01-01

    Background Decreased health-related quality of life (HRQoL) is a significant problem after an intensive care stay and is affected by several known factors such as age, sex, and previous health-state. The objective of this study was to assess the association between memory and self-reported perceived HRQoL of patients discharged from the intensive care unit (ICU). Methods A prospective, multicenter study involving nine general ICUs in Portugal. All adult patients with a length of stay >48 hours were invited to participate in a 6-month follow-up after ICU discharge by answering a set of structured questionnaires, including EuroQol 5-Dimensions and ICU memory tool. Results A total of 313 (52% of the eligible) patients agreed to enter the study. The median age of patients was 60 years old, 58% were males, the median Simplified Acute Physiology Score II (SAPS II) was 38, and the median length of stay was 8 days for ICU and 21 days for total hospital stay. Eighty-nine percent (n=276) of the admissions were emergencies. Seventy-eight percent (n=234) of the patients had memories associated with the ICU stay. Patients with no memories had 2.1 higher chances (P=0.011) of being in the bottom half of the HRQoL score (<0.5 Euro-Qol 5-Dimensions index score). Even after adjusting for pre-admission characteristics, having memories was associated with higher perceived HRQoL (adjusted odds ratio =2.1, P=0.022). Conclusion This study suggests that most of the ICU survivors have memories of their ICU stay. For the ICU survivors, having memories of the ICU stay is associated with a higher perceived HRQoL 6 months after ICU discharge. PMID:27350762

  17. Cycles in Speed-Working Memory-G Relations: Towards a Developmental-Differential Theory of the Mind

    ERIC Educational Resources Information Center

    Demetriou, Andreas; Spanoudis, George; Shayer, Michael; Mouyi, Antigoni; Kazi, Smaragda; Platsidou, Maria

    2013-01-01

    This article presents three studies, two of them longitudinal, which investigated the relations between age, processing speed, working memory (WM), and fluid intelligence ("g[subscript f]") from 4 to 16 years of age. Structural equation modeling showed that speed was a powerful covariate of age ([approximately] - 0.6 to - 0.7) from 4 to 13 years,…

  18. The Role of Recollection in Source Memory: An Examination of Schizophrenia Patients and Their First-Degree Relatives

    ERIC Educational Resources Information Center

    Achim, Amelie M.; Lefebvre, Andree-Anne; Cellard, Caroline; Bouchard, Roch-Hugo; Roy, Marc-Andre; Tremblay, Sebastien

    2011-01-01

    Source recognition memory deficits have repeatedly been observed in people with schizophrenia (SZ), and have also recently been observed in their first-degree relatives. These deficits have been hypothesized to result, at least in part, from impairments in the conscious recollection process. Although other processes are clearly also affected in…

  19. Processing Speed, Inhibitory Control, and Working Memory: Three Important Factors to Account for Age-Related Cognitive Decline

    ERIC Educational Resources Information Center

    Pereiro Rozas, Arturo X.; Juncos-Rabadan, Onesimo; Gonzalez, Maria Soledad Rodriguez

    2008-01-01

    Processing speed, inhibitory control and working memory have been identified as the main possible culprits of age-related cognitive decline. This article describes a study of their interrelationships and dependence on age, including exploration of whether any of them mediates between age and the others. We carried out a LISREL analysis of the…

  20. Distinct Discrimination Learning Strategies and Their Relation with Spatial Memory and Attentional Control in 4- to 14-Year-Olds

    ERIC Educational Resources Information Center

    Schmittmann, Verena D.; van der Maas, Han L. J.; Raijmakers, Maartje E. J.

    2012-01-01

    Behavioral, psychophysiological, and neuropsychological studies have revealed large developmental differences in various learning paradigms where learning from positive and negative feedback is essential. The differences are possibly due to the use of distinct strategies that may be related to spatial working memory and attentional control. In…

  1. Online Learning from Input versus Offline Memory Evolution in Adult Word Learning: Effects of Neighborhood Density and Phonologically Related Practice

    ERIC Educational Resources Information Center

    Storkel, Holly L.; Bontempo, Daniel E.; Pak, Natalie S.

    2014-01-01

    Purpose: In this study, the authors investigated adult word learning to determine how neighborhood density and practice across phonologically related training sets influence online learning from input during training versus offline memory evolution during no-training gaps. Method: Sixty-one adults were randomly assigned to learn low- or…

  2. The Role of Episodic Memory in Controlled Evaluative Judgments about Attitudes: An Event-Related Potential Study

    ERIC Educational Resources Information Center

    Johnson, Ray, Jr.; Simon, Elizabeth J.; Henkell, Heather; Zhu, John

    2011-01-01

    Event-related potentials (ERPs) are unique in their ability to provide information about the timing of activity in the neural networks that perform complex cognitive processes. Given the dearth of extant data from normal controls on the question of whether attitude representations are stored in episodic or semantic memory, the goal here was to…

  3. Productive Extension of Semantic Memory in School-Aged Children: Relations with Reading Comprehension and Deployment of Cognitive Resources

    ERIC Educational Resources Information Center

    Bauer, Patricia J.; Blue, Shala N.; Xu, Aoxiang; Esposito, Alena G.

    2016-01-01

    We investigated 7- to 10-year-old children's productive extension of semantic memory through self-generation of new factual knowledge derived through integration of separate yet related facts learned through instruction or through reading. In Experiment 1, an experimenter read the to-be-integrated facts. Children successfully learned and…

  4. Age-Related Effects of Study Time Allocation on Memory Performance in a Verbal and a Spatial Task

    ERIC Educational Resources Information Center

    Krueger, Lacy E.

    2012-01-01

    Past studies have suggested that study time allocation partially mediates age relations on memory performance in a verbal task. To identify whether this applied to a different material modality, participants ages 20-87 completed a spatial task in addition to a traditional verbal task. In both the verbal and the spatial task, increased age was…

  5. Declarative memory.

    PubMed

    Riedel, Wim J; Blokland, Arjan

    2015-01-01

    Declarative Memory consists of memory for events (episodic memory) and facts (semantic memory). Methods to test declarative memory are key in investigating effects of potential cognition-enhancing substances--medicinal drugs or nutrients. A number of cognitive performance tests assessing declarative episodic memory tapping verbal learning, logical memory, pattern recognition memory, and paired associates learning are described. These tests have been used as outcome variables in 34 studies in humans that have been described in the literature in the past 10 years. Also, the use of episodic tests in animal research is discussed also in relation to the drug effects in these tasks. The results show that nutritional supplementation of polyunsaturated fatty acids has been investigated most abundantly and, in a number of cases, but not all, show indications of positive effects on declarative memory, more so in elderly than in young subjects. Studies investigating effects of registered anti-Alzheimer drugs, cholinesterase inhibitors in mild cognitive impairment, show positive and negative effects on declarative memory. Studies mainly carried out in healthy volunteers investigating the effects of acute dopamine stimulation indicate enhanced memory consolidation as manifested specifically by better delayed recall, especially at time points long after learning and more so when drug is administered after learning and if word lists are longer. The animal studies reveal a different picture with respect to the effects of different drugs on memory performance. This suggests that at least for episodic memory tasks, the translational value is rather poor. For the human studies, detailed parameters of the compositions of word lists for declarative memory tests are discussed and it is concluded that tailored adaptations of tests to fit the hypothesis under study, rather than "off-the-shelf" use of existing tests, are recommended. PMID:25977084

  6. Dynamic relation between working memory capacity and speech recognition in noise during the first 6 months of hearing aid use.

    PubMed

    Ng, Elaine H N; Classon, Elisabet; Larsby, Birgitta; Arlinger, Stig; Lunner, Thomas; Rudner, Mary; Rönnberg, Jerker

    2014-01-01

    The present study aimed to investigate the changing relationship between aided speech recognition and cognitive function during the first 6 months of hearing aid use. Twenty-seven first-time hearing aid users with symmetrical mild to moderate sensorineural hearing loss were recruited. Aided speech recognition thresholds in noise were obtained in the hearing aid fitting session as well as at 3 and 6 months postfitting. Cognitive abilities were assessed using a reading span test, which is a measure of working memory capacity, and a cognitive test battery. Results showed a significant correlation between reading span and speech reception threshold during the hearing aid fitting session. This relation was significantly weakened over the first 6 months of hearing aid use. Multiple regression analysis showed that reading span was the main predictor of speech recognition thresholds in noise when hearing aids were first fitted, but that the pure-tone average hearing threshold was the main predictor 6 months later. One way of explaining the results is that working memory capacity plays a more important role in speech recognition in noise initially rather than after 6 months of use. We propose that new hearing aid users engage working memory capacity to recognize unfamiliar processed speech signals because the phonological form of these signals cannot be automatically matched to phonological representations in long-term memory. As familiarization proceeds, the mismatch effect is alleviated, and the engagement of working memory capacity is reduced. PMID:25421088

  7. The relative success of a self-help and a group-based memory training program for older adults.

    PubMed

    Hastings, Erin C; West, Robin L

    2009-09-01

    This study evaluates self-help and group-based memory training programs to test for their differential impact on memory beliefs and performance. Self-help participants used a manual that presented strategies for name, story, and list recall and practice exercises. Matched content from that same manual was presented by the trainer in 2-hr weekly group sessions for the group-based trainees. Relative to a wait-list control group, most memory measures showed significant gains for both self-help and group-based training, with no significant training condition differences, and these gains were maintained at follow-up. Belief measures showed that locus of control was significantly higher for the self-help and group-based training than the control group; memory self-efficacy significantly declined for controls, increased for group-trained participants, and remained constant in the self-help group. Self-efficacy change in a self-help group may require more opportunities for interacting with peers and/or an instructor emphasizing one's potential for memory change. PMID:19739914

  8. Dynamic Relation Between Working Memory Capacity and Speech Recognition in Noise During the First 6 Months of Hearing Aid Use

    PubMed Central

    Classon, Elisabet; Larsby, Birgitta; Arlinger, Stig; Lunner, Thomas; Rudner, Mary; Rönnberg, Jerker

    2014-01-01

    The present study aimed to investigate the changing relationship between aided speech recognition and cognitive function during the first 6 months of hearing aid use. Twenty-seven first-time hearing aid users with symmetrical mild to moderate sensorineural hearing loss were recruited. Aided speech recognition thresholds in noise were obtained in the hearing aid fitting session as well as at 3 and 6 months postfitting. Cognitive abilities were assessed using a reading span test, which is a measure of working memory capacity, and a cognitive test battery. Results showed a significant correlation between reading span and speech reception threshold during the hearing aid fitting session. This relation was significantly weakened over the first 6 months of hearing aid use. Multiple regression analysis showed that reading span was the main predictor of speech recognition thresholds in noise when hearing aids were first fitted, but that the pure-tone average hearing threshold was the main predictor 6 months later. One way of explaining the results is that working memory capacity plays a more important role in speech recognition in noise initially rather than after 6 months of use. We propose that new hearing aid users engage working memory capacity to recognize unfamiliar processed speech signals because the phonological form of these signals cannot be automatically matched to phonological representations in long-term memory. As familiarization proceeds, the mismatch effect is alleviated, and the engagement of working memory capacity is reduced. PMID:25421088

  9. Characterizing “fibrofog”: Subjective appraisal, objective performance, and task-related brain activity during a working memory task

    PubMed Central

    Walitt, Brian; Čeko, Marta; Khatiwada, Manish; Gracely, John L.; Rayhan, Rakib; VanMeter, John W.; Gracely, Richard H.

    2016-01-01

    The subjective experience of cognitive dysfunction (“fibrofog”) is common in fibromyalgia. This study investigated the relation between subjective appraisal of cognitive function, objective cognitive task performance, and brain activity during a cognitive task using functional magnetic resonance imaging (fMRI). Sixteen fibromyalgia patients and 13 healthy pain-free controls completed a battery of questionnaires, including the Multiple Ability Self-Report Questionnaire (MASQ), a measure of self-perceived cognitive difficulties. Participants were evaluated for working memory performance using a modified N-back working memory task while undergoing Blood Oxygen Level Dependent (BOLD) fMRI measurements. Fibromyalgia patients and controls did not differ in working memory performance. Subjective appraisal of cognitive function was associated with better performance (accuracy) on the working memory task in healthy controls but not in fibromyalgia patients. In fibromyalgia patients, increased perceived cognitive difficulty was positively correlated with the severity of their symptoms. BOLD response during the working memory task did not differ between the groups. BOLD response correlated with task accuracy in control subjects but not in fibromyalgia patients. Increased subjective cognitive impairment correlated with decreased BOLD response in both groups but in different anatomic regions. In conclusion, “fibrofog” appears to be better characterized by subjective rather than objective impairment. Neurologic correlates of this subjective experience of impairment might be separate from those involved in the performance of cognitive tasks. PMID:26955513

  10. Co-design of application software and NAND flash memory in solid-state drive for relational database storage system

    NASA Astrophysics Data System (ADS)

    Miyaji, Kousuke; Sun, Chao; Soga, Ayumi; Takeuchi, Ken

    2014-01-01

    A relational database management system (RDBMS) is designed based on NAND flash solid-state drive (SSD) for storage. By vertically integrating the storage engine (SE) and the flash translation layer (FTL), system performance is maximized and the internal SSD overhead is minimized. The proposed RDBMS SE utilizes physical information about the NAND flash memory which is supplied from the FTL. The query operation is also optimized for SSD. By these treatments, page-copy-less garbage collection is achieved and data fragmentation in the NAND flash memory is suppressed. As a result, RDBMS performance increases by 3.8 times, power consumption of SSD decreases by 46% and SSD life time is increased by 61%. The effectiveness of the proposed scheme increases with larger erase block sizes, which matches the future scaling trend of three-dimensional (3D-) NAND flash memories. The preferable row data size of the proposed scheme is below 500 byte for 16 kbyte page size.

  11. Relation between Working Memory Capacity and Auditory Stream Segregation in Children with Auditory Processing Disorder

    PubMed Central

    Lotfi, Yones; Mehrkian, Saiedeh; Moossavi, Abdollah; Zadeh, Soghrat Faghih; Sadjedi, Hamed

    2016-01-01

    Background: This study assessed the relationship between working memory capacity and auditory stream segregation by using the concurrent minimum audible angle in children with a diagnosed auditory processing disorder (APD). Methods: The participants in this cross-sectional, comparative study were 20 typically developing children and 15 children with a diagnosed APD (age, 9–11 years) according to the subtests of multiple-processing auditory assessment. Auditory stream segregation was investigated using the concurrent minimum audible angle. Working memory capacity was evaluated using the non-word repetition and forward and backward digit span tasks. Nonparametric statistics were utilized to compare the between-group differences. The Pearson correlation was employed to measure the degree of association between working memory capacity and the localization tests between the 2 groups. Results: The group with APD had significantly lower scores than did the typically developing subjects in auditory stream segregation and working memory capacity. There were significant negative correlations between working memory capacity and the concurrent minimum audible angle in the most frontal reference location (0° azimuth) and lower negative correlations in the most lateral reference location (60° azimuth) in the children with APD. Conclusion: The study revealed a relationship between working memory capacity and auditory stream segregation in children with APD. The research suggests that lower working memory capacity in children with APD may be the possible cause of the inability to segregate and group incoming information. PMID:26989281

  12. FLOW GATING

    DOEpatents

    Poppelbaum, W.J.

    1962-12-01

    BS>This invention is a fast gating system for eiectronic flipflop circuits. Diodes connect the output of one circuit to the input of another, and the voltage supply for the receiving flip-flop has two alternate levels. When the supply is at its upper level, no current can flow through the diodes, but when the supply is at its lower level, current can flow to set the receiving flip- flop to the same state as that of the circuit to which it is connected. (AEC)

  13. Effect of salinity changes on olfactory memory-related genes and hormones in adult chum salmon Oncorhynchus keta.

    PubMed

    Kim, Na Na; Choi, Young Jae; Lim, Sang-Gu; Jeong, Minhwan; Jin, Deuk-Hee; Choi, Cheol Young

    2015-09-01

    Studies of memory formation have recently concentrated on the possible role of N-methyl-d-aspartate receptors (NRs). We examined changes in the expression of three NRs (NR1, NR2B, and NR2C), olfactory receptor (OR), and adrenocorticotropic hormone (ACTH) in chum salmon Oncorhynchus keta using quantitative polymerase chain reaction (QPCR) during salinity change (seawater→50% seawater→freshwater). NRs were significantly detected in the diencephalon and telencephalon and OR was significantly detected in the olfactory epithelium. The expression of NRs, OR, and ACTH increased after the transition to freshwater. We also determined that treatment with MK-801, an antagonist of NRs, decreased NRs in telencephalon cells. In addition, a reduction in salinity was associated with increased levels of dopamine, ACTH, and cortisol (in vivo). Reductions in salinity evidently caused NRs and OR to increase the expression of cortisol and dopamine. We concluded that memory capacity and olfactory imprinting of salmon is related to the salinity of the environment during the migration to spawning sites. Furthermore, salinity affects the memory/imprinting and olfactory abilities, and cortisol and dopamine is also related with olfactory-related memories during migration. PMID:25933936

  14. A wearable multiplexed silicon nonvolatile memory array using nanocrystal charge confinement

    PubMed Central

    Kim, Jaemin; Son, Donghee; Lee, Mincheol; Song, Changyeong; Song, Jun-Kyul; Koo, Ja Hoon; Lee, Dong Jun; Shim, Hyung Joon; Kim, Ji Hoon; Lee, Minbaek; Hyeon, Taeghwan; Kim, Dae-Hyeong

    2016-01-01

    Strategies for efficient charge confinement in nanocrystal floating gates to realize high-performance memory devices have been investigated intensively. However, few studies have reported nanoscale experimental validations of charge confinement in closely packed uniform nanocrystals and related device performance characterization. Furthermore, the system-level integration of the resulting devices with wearable silicon electronics has not yet been realized. We introduce a wearable, fully multiplexed silicon nonvolatile memory array with nanocrystal floating gates. The nanocrystal monolayer is assembled over a large area using the Langmuir-Blodgett method. Efficient particle-level charge confinement is verified with the modified atomic force microscopy technique. Uniform nanocrystal charge traps evidently improve the memory window margin and retention performance. Furthermore, the multiplexing of memory devices in conjunction with the amplification of sensor signals based on ultrathin silicon nanomembrane circuits in stretchable layouts enables wearable healthcare applications such as long-term data storage of monitored heart rates. PMID:26763827

  15. Detail view of stone entrance gate pylon showing carved site ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail view of stone entrance gate pylon showing carved site name and Great Seal of the United States. View looking northeast. - Flanders Field American Cemetery & Memorial, Wortegemseweg 117, Waregem, West Flanders (Belgium)

  16. Why distinctive information reduces false memories: evidence for both impoverished relational-encoding and distinctiveness heuristic accounts.

    PubMed

    Hege, Amanda C G; Dodson, Chad S

    2004-07-01

    Two accounts explain why studying pictures reduces false memories within the Deese-Roediger-McDermott paradigm (J. Deese, 1959; H. L. Roediger & K. B. McDermott, 1995). The impoverished relational-encoding account suggests that studying pictures interferes with the encoding of relational information, which is the primary basis for false memories in this paradigm. Alternatively, the distinctiveness heuristic assumes that critical lures are actively withheld by the use of a retrieval strategy. When participants were given inclusion recall instructions to report studied items as well as related items, they still reported critical lures less often after picture encoding than they did after word encoding. As the impoverished relational-encoding account suggests, critical lures appear less likely to come to mind after picture encoding than they do after word encoding. However, the results from a postrecall recognition test provide evidence in favor of the distinctiveness heuristic. PMID:15238023

  17. Morris water maze: procedures for assessing spatial and related forms of learning and memory.

    PubMed

    Vorhees, Charles V; Williams, Michael T

    2006-01-01

    The Morris water maze (MWM) is a test of spatial learning for rodents that relies on distal cues to navigate from start locations around the perimeter of an open swimming arena to locate a submerged escape platform. Spatial learning is assessed across repeated trials and reference memory is determined by preference for the platform area when the platform is absent. Reversal and shift trials enhance the detection of spatial impairments. Trial-dependent, latent and discrimination learning can be assessed using modifications of the basic protocol. Search-to-platform area determines the degree of reliance on spatial versus non-spatial strategies. Cued trials determine whether performance factors that are unrelated to place learning are present. Escape from water is relatively immune from activity or body mass differences, making it ideal for many experimental models. The MWM has proven to be a robust and reliable test that is strongly correlated with hippocampal synaptic plasticity and NMDA receptor function. We present protocols for performing variants of the MWM test, from which results can be obtained from individual animals in as few as 6 days. PMID:17406317

  18. The relation of the cortisol awakening response and prospective memory functioning in young children.

    PubMed

    Bäumler, Damaris; Voigt, Babett; Miller, Robert; Stalder, Tobias; Kirschbaum, Clemens; Kliegel, Matthias

    2014-05-01

    Recent research suggests that the cortisol awakening response (CAR) is linked to cognitive functions depending on hippocampal and frontal cortex circuits and may possibly be modulated by prospective memory (PM). However, the link between the CAR and PM abilities has not been investigated so far. Addressing this open issue, we report data from 97 children aged 37-87 months. Salivary cortisol levels were assessed 0 and 30 min post-awakening over three study days. Thereby a valid CAR measurement was ensured by using objective measures of awakening and sampling times. A game-like task served as behavioral measure of PM performance. Bayesian analysis revealed a positive association between children's PM performance and the CAR, with better PM performance being related to a greater CAR. This association persisted after controlling for age. Overall, the current finding supports the prediction that PM functioning may be linked to the CAR, possibly as both the CAR and PM rely on a common neurophysiological basis. PMID:24582874

  19. Recognition memory for emotional and neutral faces: an event-related potential study.

    PubMed

    Johansson, Mikael; Mecklinger, Axel; Treese, Anne-Cécile

    2004-12-01

    This study examined emotional influences on the hypothesized event-related potential (ERP) correlates of familiarity and recollection (Experiment 1) and the states of awareness (Experiment 2) accompanying recognition memory for faces differing in facial affect. Participants made gender judgments to positive, negative, and neutral faces at study and were in the test phase instructed to discriminate between studied and nonstudied faces. Whereas old-new discrimination was unaffected by facial expression, negative faces were recollected to a greater extent than both positive and neutral faces as reflected in the parietal ERP old-new effect and in the proportion of remember judgments. Moreover, emotion-specific modulations were observed in frontally recorded ERPs elicited by correctly rejected new faces that concurred with a more liberal response criterion for emotional as compared to neutral faces. Taken together, the results are consistent with the view that processes promoting recollection are facilitated for negative events and that emotion may affect recognition performance by influencing criterion setting mediated by the prefrontal cortex. PMID:15701233

  20. Inferring Facts From Fiction: Reading Correct and Incorrect Information Affects Memory for Related Information

    PubMed Central

    Butler, Andrew C.; Dennis, Nancy A.; Marsh, Elizabeth J.

    2012-01-01

    People can acquire both true and false knowledge about the world from fictional stories (Marsh & Fazio, 2007). The present study explored whether the benefits and costs of learning about the world from fictional stories extend beyond memory for directly stated pieces of information. Of interest was whether readers would use correct and incorrect story references to make deductive inferences about related information in the story, and then integrate those inferences into their knowledge bases. Subjects read stories containing correct, neutral, and misleading references to facts about the world; each reference could be combined with another reference that occurred in a later sentence to make a deductive inference. Later, they answered general knowledge questions that tested for these deductive inferences. The results showed that subjects generated and retained the deductive inferences regardless of whether the inferences were consistent or inconsistent with world knowledge, and irrespective of whether the references were placed consecutively in the text or separated by many sentences. Readers learn more than what is directly stated in stories; they use references to the real world to make both correct and incorrect inferences that are integrated into their knowledge bases. PMID:22640369

  1. Expertise, Working Memory and Articulatory Suppression Effect: Their Relation with Simultaneous Interpreting Performance

    PubMed Central

    Injoque-Ricle, Irene; Barreyro, Juan Pablo; Formoso, Jesica; Jaichenco, Virginia I.

    2015-01-01

    Simultaneous interpreting is a complex bilingual verbal activity that involves the auditory perception of an oral communication and the production of a coherent discourse. One of the cognitive functions underlying simultaneous interpreting is working memory. The aim of this work was to study the relationship between expertise, working memory capacity and articulatory suppression effect, and the ability to perform simultaneous interpreting. For this purpose, four working memory tasks and one simultaneous interpreting task were administered to thirty Spanish-speaking professional English interpreters. Results showed that simultaneous interpreting ability might be supported by the working memory´s capacity to store or process information, but also by the ability of the interpreter to cope with the articulatory suppression effect. We conclude that interpreters may have or develop resources to support the effect caused by articulatory suppression. PMID:26207153

  2. β-amyloid disrupts human NREM slow waves and related hippocampus-dependent memory consolidation

    PubMed Central

    Mander, Bryce A.; Marks, Shawn M.; Vogel, Jacob W.; Rao, Vikram; Lu, Brandon; Saletin, Jared M.; Ancoli-Israel, Sonia; Jagust, William J.; Walker, Matthew P.

    2015-01-01

    Independent evidence associates β-amyloid pathology with both NREM sleep disruption and memory impairment in older adults. However, whether the influence of β-amyloid pathology on hippocampus-dependent memory is, in part, driven by impairments of NREM slow wave activity (SWA) and associated overnight memory consolidation is unknown. Here, we show that β-amyloid burden within medial prefrontal cortex (mPFC) is significantly correlated with the severity of impairment in NREM SWA generation. Moreover, reduced NREM SWA generation was further associated with impaired overnight memory consolidation and impoverished hippocampal-neocortical memory transformation. Furthermore, structural equation models revealed that the association between mPFC β-amyloid pathology and impaired hippocampus-dependent memory consolidation is not direct, but instead, statistically depends on the intermediary factor of diminished NREM SWA. By linking β-amyloid pathology with impaired NREM SWA, these data implicate sleep disruption as a novel mechanistic pathway through which β-amyloid pathology may contribute to hippocampus-dependent cognitive decline in the elderly. PMID:26030850

  3. β-amyloid disrupts human NREM slow waves and related hippocampus-dependent memory consolidation.

    PubMed

    Mander, Bryce A; Marks, Shawn M; Vogel, Jacob W; Rao, Vikram; Lu, Brandon; Saletin, Jared M; Ancoli-Israel, Sonia; Jagust, William J; Walker, Matthew P

    2015-07-01

    Independent evidence associates β-amyloid pathology with both non-rapid eye movement (NREM) sleep disruption and memory impairment in older adults. However, whether the influence of β-amyloid pathology on hippocampus-dependent memory is, in part, driven by impairments of NREM slow wave activity (SWA) and associated overnight memory consolidation is unknown. Here we show that β-amyloid burden in medial prefrontal cortex (mPFC) correlates significantly with the severity of impairment in NREM SWA generation. Moreover, reduced NREM SWA generation was further associated with impaired overnight memory consolidation and impoverished hippocampal-neocortical memory transformation. Furthermore, structural equation models revealed that the association between mPFC β-amyloid pathology and impaired hippocampus-dependent memory consolidation was not direct, but instead statistically depended on the intermediary factor of diminished NREM SWA. By linking β-amyloid pathology with impaired NREM SWA, these data implicate sleep disruption as a mechanistic pathway through which β-amyloid pathology may contribute to hippocampus-dependent cognitive decline in the elderly. PMID:26030850

  4. Saturation of auditory short-term memory causes a plateau in the sustained anterior negativity event-related potential.

    PubMed

    Alunni-Menichini, Kristelle; Guimond, Synthia; Bermudez, Patrick; Nolden, Sophie; Lefebvre, Christine; Jolicoeur, Pierre

    2014-12-10

    The maintenance of information in auditory short-term memory (ASTM) is accompanied by a sustained anterior negativity (SAN) in the event-related potential measured during the retention interval of simple auditory memory tasks. Previous work on ASTM showed that the amplitude of the SAN increased in negativity as the number of maintained items increases. The aim of the current study was to measure the SAN and observe its behavior beyond the point of saturation of auditory short-term memory. We used atonal pure tones in sequences of 2, 4, 6, or 8t. Our results showed that the amplitude of SAN increased in negativity from 2 to 4 items and then levelled off from 4 to 8 items. Behavioral results suggested that the average span in the task was slightly below 3, which was consistent with the observed plateau in the electrophysiological results. Furthermore, the amplitude of the SAN predicted individual differences in auditory memory capacity. The results support the hypothesis that the SAN is an electrophysiological index of brain activity specifically related to the maintenance of auditory information in ASTM. PMID:25446005

  5. The role of relational binding in item memory: evidence from face recognition in a case of developmental amnesia.

    PubMed

    Olsen, Rosanna K; Lee, Yunjo; Kube, Jana; Rosenbaum, R Shayna; Grady, Cheryl L; Moscovitch, Morris; Ryan, Jennifer D

    2015-04-01

    Current theories state that the hippocampus is responsible for the formation of memory representations regarding relations, whereas extrahippocampal cortical regions support representations for single items. However, findings of impaired item memory in hippocampal amnesics suggest a more nuanced role for the hippocampus in item memory. The hippocampus may be necessary when the item elements need to be bound within and across episodes to form a lasting representation that can be used flexibly. The current investigation was designed to test this hypothesis in face recognition. H.C., an individual who developed with a compromised hippocampal system, and control participants incidentally studied individual faces that either varied in presentation viewpoint across study repetitions or remained in a fixed viewpoint across the study repetitions. Eye movements were recorded during encoding and participants then completed a surprise recognition memory test. H.C. demonstrated altered face viewing during encoding. Although the overall number of fixations made by H.C. was not significantly different from that of controls, the distribution of her viewing was primarily directed to the eye region. Critically, H.C. was significantly impaired in her ability to subsequently recognize faces studied from variable viewpoints, but demonstrated spared performance in recognizing faces she encoded from a fixed viewpoint, implicating a relationship between eye movement behavior in the service of a hippocampal binding function. These findings suggest that a compromised hippocampal system disrupts the ability to bind item features within and across study repetitions, ultimately disrupting recognition when it requires access to flexible relational representations. PMID:25834058

  6. Treatment of age-related memory complaints with Ginkgo biloba extract: a randomized double blind placebo-controlled study.

    PubMed

    Brautigam, M R; Blommaert, F A; Verleye, G; Castermans, J; Jansen Steur, E N; Kleijnen, J

    1998-12-01

    A growing number of people is subject to age-related cognitive impairment due to the proportional increase of the ageing population. Therefore, there is a growing interest in cognition-enhancing substances. The efficacy of an alcohol/water extract of Ginkgo biloba in elderly individuals with memory- and/or concentration complaints was tested in a randomized, double-blind, placebo-controlled study by using both subjective and objective parameters. After a wash-out period of 4 weeks 241 non-institutionalised patients in the age range 55-86 years were randomly allocated to receive either Ginkgo biloba alcohol/water extract in a high dose (HD), a low dose (LD) or a placebo (PL) for 24 weeks. Patients were assessed using a psychometric testbattery in the following order: Expended Mental Control Test (EMCT) measuring attention and concentration, Benton Test of Visual Retention-Revised (measures short term visual memory), Rey Test part 1 (measures short term memory and learning curve), Beck Depressive Inventory (BDI) measuring the presence and severeness of a depression in order to exclude depressive patients and Rey Test part 2 (measures long term memory: recognition). Furthermore, subjective perception of memory and concentration was measured. 197 patients completed the study (mean MMSE score: 26.29). In the subjective test, the EMCT, the Rey 1 and Rey 2 no significant differences in improvement in time between the groups were observed. In the Benton test increases of 18%, 26% and 11% (expressed as percentage of baseline scores) were observed in the HD, LD and PL respectively (MANOVA; p = 0.0076). No substantial correlation was observed between subjective perception of the severeness of memory complaints and the objective test results. No differences in the number of (gastrointestinal) side effects were observed between placebo and verum groups. These results indicate that the use of Ginkgo extracts in elderly individuals with cognitive impairment might be promising

  7. The effect of resveratrol on beta amyloid-induced memory impairment involves inhibition of phosphodiesterase-4 related signaling.

    PubMed

    Wang, Gang; Chen, Ling; Pan, Xiaoyu; Chen, Jiechun; Wang, Liqun; Wang, Weijie; Cheng, Ruochuan; Wu, Fan; Feng, Xiaoqing; Yu, Yingcong; Zhang, Han-Ting; O'Donnell, James M; Xu, Ying

    2016-04-01

    Resveratrol, a natural polyphenol found in red wine, has wide spectrum of pharmacological properties including antioxidative and antiaging activities. Beta amyloid peptides (Aβ) are known to involve cognitive impairment, neuroinflammatory and apoptotic processes in Alzheimer's disease (AD). Activation of cAMP and/or cGMP activities can improve memory performance and decrease the neuroinflammation and apoptosis. However, it remains unknown whether the memory enhancing effect of resveratrol on AD associated cognitive disorders is related to the inhibition of phosphodiesterase 4 (PDE4) subtypes and subsequent increases in intracellular cAMP and/or cGMP activities. This study investigated the effect of resveratrol on Aβ1-42-induced cognitive impairment and the participation of PDE4 subtypes related cAMP or cGMP signaling. Mice microinfused with Aβ1-42 into bilateral CA1 subregions displayed learning and memory impairment, as evidenced by reduced memory acquisition and retrieval in the water maze and retention in the passive avoidance tasks; it was also significant that neuroinflammatory and pro-apoptotic factors were increased in Aβ1-42-treated mice. Aβ1-42-treated mice also increased in PDE4A, 4B and 4D expression, and decreased in PKA level. However, PKA inhibitor H89, but not PKG inhibitor KT5823, prevented resveratrol's effects on these parameters. Resveratrol also reversed Aβ1-42-induced decreases in phosphorylated cAMP response-element binding protein (pCREB), brain derived neurotrophic factor (BDNF) and anti-apoptotic factor BCl-2 expression, which were reversed by H89. These findings suggest that resveratrol reversing Aβ-induced learning and memory disorder may involve the regulation of neuronal inflammation and apoptosis via PDE4 subtypes related cAMP-CREB-BDNF signaling. PMID:26980711

  8. The effect of resveratrol on beta amyloid-induced memory impairment involves inhibition of phosphodiesterase-4 related signaling

    PubMed Central

    Wang, Gang; Chen, Ling; Pan, Xiaoyu; Chen, Jiechun; Wang, Liqun; Wang, Weijie; Cheng, Ruochuan; Wu, Fan; Feng, Xiaoqing; Yu, Yingcong; Zhang, Han-Ting; O'Donnell, James M.; Xu, Ying

    2016-01-01

    Resveratrol, a natural polyphenol found in red wine, has wide spectrum of pharmacological properties including antioxidative and antiaging activities. Beta amyloid peptides (Aβ) are known to involve cognitive impairment, neuroinflammatory and apoptotic processes in Alzheimer's disease (AD). Activation of cAMP and/or cGMP activities can improve memory performance and decrease the neuroinflammation and apoptosis. However, it remains unknown whether the memory enhancing effect of resveratrol on AD associated cognitive disorders is related to the inhibition of phosphodiesterase 4 (PDE4) subtypes and subsequent increases in intracellular cAMP and/or cGMP activities. This study investigated the effect of resveratrol on Aβ1-42-induced cognitive impairment and the participation of PDE4 subtypes related cAMP or cGMP signaling. Mice microinfused with Aβ1-42 into bilateral CA1 subregions displayed learning and memory impairment, as evidenced by reduced memory acquisition and retrieval in the water maze and retention in the passive avoidance tasks; it was also significant that neuroinflammatory and pro-apoptotic factors were increased in Aβ1-42-treated mice. Aβ1-42-treated mice also increased in PDE4A, 4B and 4D expression, and decreased in PKA level. However, PKA inhibitor H89, but not PKG inhibitor KT5823, prevented resveratrol's effects on these parameters. Resveratrol also reversed Aβ1-42-induced decreases in phosphorylated cAMP response-element binding protein (pCREB), brain derived neurotrophic factor (BDNF) and anti-apoptotic factor BCl-2 expression, which were reversed by H89. These findings suggest that resveratrol reversing Aβ-induced learning and memory disorder may involve the regulation of neuronal inflammation and apoptosis via PDE4 subtypes related cAMP-CREB-BDNF signaling. PMID:26980711

  9. Medial Prefrontal Functional Connectivity--Relation to Memory Self-Appraisal Accuracy in Older Adults with and without Memory Disorders

    ERIC Educational Resources Information Center

    Ries, Michele L.; McLaren, Donald G.; Bendlin, Barbara B.; Xu, Guofan; Rowley, Howard A.; Birn, Rasmus; Kastman, Erik K.; Sager, Mark A.; Asthana, Sanjay; Johnson, Sterling C.

    2012-01-01

    It is tentatively estimated that 25% of people with early Alzheimer's disease (AD) show impaired awareness of disease-related changes in their own cognition. Research examining both normative self-awareness and altered awareness resulting from brain disease or injury points to the central role of the medial prefrontal cortex (MPFC) in generating…

  10. Characteristics Of Ferroelectric Logic Gates Using a Spice-Based Model

    NASA Technical Reports Server (NTRS)

    MacLeod, Todd C.; Phillips, Thomas A.; Ho, Fat D.

    2005-01-01

    A SPICE-based model of an n-channel ferroelectric field effect transistor has been developed based on both theoretical and empirical data. This model was used to generate the I-V characteristic of several logic gates. The use of ferroelectric field effect transistors in memory circuits is being developed by several organizations. The use of FFETs in other circuits, both analog and digital needs to be better understood. The ability of FFETs to have different characteristics depending on the initial polarization can be used to create logic gates. These gates can have properties not available to standard CMOS logic gates, such as memory, reconfigurability and memory. This paper investigates basic properties of FFET logic gates. It models FFET inverter, NAND gate and multi-input NAND gate. The I-V characteristics of the gates are presented as well as transfer characteristics and timing. The model used is a SPICE-based model developed from empirical data from actual Ferroelectric transistors. It simulates all major characteristics of the ferroelectric transistor, including polarization, hysteresis and decay. Contrasts are made of the differences between FFET logic gates and CMOS logic gates. FFET parameters are varied to show the effect on the overall gate. A recodigurable gate is investigated which is not possible with CMOS circuits. The paper concludes that FFETs can be used in logic gates and have several advantages over standard CMOS gates.

  11. Molecular Mechanism for Age-Related Memory Loss: The Histone-Binding Protein RbAp48

    PubMed Central

    Pavlopoulos, Elias; Jones, Sidonie; Kosmidis, Stylianos; Close, Maggie; Kim, Carla; Kovalerchik, Olga; Small, Scott A.; Kandel, Eric R.

    2016-01-01

    To distinguish age-related memory loss more explicitly from Alzheimer’s disease (AD), we have explored its molecular underpinning in the dentate gyrus (DG), a subregion of the hippocampal formation thought to be targeted by aging. We carried out a gene expression study in human postmortem tissue harvested from both DG and entorhinal cortex (EC), a neighboring subregion unaffected by aging and known to be the site of onset of AD. Using expression in the EC for normalization, we identified 17 genes that manifested reliable age-related changes in the DG. The most significant change was an age-related decline in RbAp48, a histone-binding protein that modifies histone acetylation. To test whether the RbAp48 decline could be responsible for age-related memory loss, we turned to mice and found that, consistent with humans, RbAp48 was less abundant in the DG of old than in young mice. We next generated a transgenic mouse that expressed a dominant-negative inhibitor of RbAp48 in the adult forebrain. Inhibition of RbAp48 in young mice caused hippocampus-dependent memory deficits similar to those associated with aging, as measured by novel object recognition and Morris water maze tests. Functional magnetic resonance imaging studies showed that within the hippocampal formation, dysfunction was selectively observed in the DG, and this corresponded to a regionally selective decrease in histone acetylation. Up-regulation of RbAp48 in the DG of aged wild-type mice ameliorated age-related hippocampus-based memory loss and age-related abnormalities in histone acetylation. Together, these findings show that the DG is a hippocampal subregion targeted by aging, and identify molecular mechanisms of cognitive aging that could serve as valid targets for therapeutic intervention. PMID:23986399

  12. Molecular mechanism for age-related memory loss: the histone-binding protein RbAp48.

    PubMed

    Pavlopoulos, Elias; Jones, Sidonie; Kosmidis, Stylianos; Close, Maggie; Kim, Carla; Kovalerchik, Olga; Small, Scott A; Kandel, Eric R

    2013-08-28

    To distinguish age-related memory loss more explicitly from Alzheimer's disease (AD), we have explored its molecular underpinning in the dentate gyrus (DG), a subregion of the hippocampal formation thought to be targeted by aging. We carried out a gene expression study in human postmortem tissue harvested from both DG and entorhinal cortex (EC), a neighboring subregion unaffected by aging and known to be the site of onset of AD. Using expression in the EC for normalization, we identified 17 genes that manifested reliable age-related changes in the DG. The most significant change was an age-related decline in RbAp48, a histone-binding protein that modifies histone acetylation. To test whether the RbAp48 decline could be responsible for age-related memory loss, we turned to mice and found that, consistent with humans, RbAp48 was less abundant in the DG of old than in young mice. We next generated a transgenic mouse that expressed a dominant-negative inhibitor of RbAp48 in the adult forebrain. Inhibition of RbAp48 in young mice caused hippocampus-dependent memory deficits similar to those associated with aging, as measured by novel object recognition and Morris water maze tests. Functional magnetic resonance imaging studies showed that within the hippocampal formation, dysfunction was selectively observed in the DG, and this corresponded to a regionally selective decrease in histone acetylation. Up-regulation of RbAp48 in the DG of aged wild-type mice ameliorated age-related hippocampus-based memory loss and age-related abnormalities in histone acetylation. Together, these findings show that the DG is a hippocampal subregion targeted by aging, and identify molecular mechanisms of cognitive aging that could serve as valid targets for therapeutic intervention. PMID:23986399

  13. Early auditory evoked potential is modulated by selective attention and related to individual differences in visual working memory capacity.

    PubMed

    Giuliano, Ryan J; Karns, Christina M; Neville, Helen J; Hillyard, Steven A

    2014-12-01

    A growing body of research suggests that the predictive power of working memory (WM) capacity for measures of intellectual aptitude is due to the ability to control attention and select relevant information. Crucially, attentional mechanisms implicated in controlling access to WM are assumed to be domain-general, yet reports of enhanced attentional abilities in individuals with larger WM capacities are primarily within the visual domain. Here, we directly test the link between WM capacity and early attentional gating across sensory domains, hypothesizing that measures of visual WM capacity should predict an individual's capacity to allocate auditory selective attention. To address this question, auditory ERPs were recorded in a linguistic dichotic listening task, and individual differences in ERP modulations by attention were correlated with estimates of WM capacity obtained in a separate visual change detection task. Auditory selective attention enhanced ERP amplitudes at an early latency (ca. 70-90 msec), with larger P1 components elicited by linguistic probes embedded in an attended narrative. Moreover, this effect was associated with greater individual estimates of visual WM capacity. These findings support the view that domain-general attentional control mechanisms underlie the wide variation of WM capacity across individuals. PMID:25000526

  14. Age and gender-related differences in a spatial memory task in humans.

    PubMed

    León, Irene; Tascón, Laura; Cimadevilla, José Manuel

    2016-06-01

    Cognitive skills decline with age. Our ability to keep oriented in our surrounding environment was demonstrated to be influenced by factors like age and gender. Introduction of virtual reality based tasks improved assessment of spatial memory in humans. In this study, spatial orientation was assessed in a virtual memory task in order to determine the effect of aging and gender on navigational skills. Subjects from 45 to 74 years of age were organized in three groups (45-54, 55-64, 65-74 years old). Two levels of difficulty were considered. Results showed that males outperformed females in 65-74 years-old group. In addition to this, females showed a more noticeable poor performance in spatial memory than males, since memory differences appeared between all age groups. On the other hand, 65-74 year-old males showed an impaired performance in comparison with 45-54 year-old group. These results support that spatial memory becomes less accurate as we age and gender is an important factor influencing spatial orientation skills. PMID:26965569

  15. Mechanisms Underlying Age- and Performance-related Differences in Working Memory

    PubMed Central

    Daffner, Kirk R.; Chong, Hyemi; Sun, Xue; Tarbi, Elise C.; Riis, Jenna L.; McGinnis, Scott M.; Holcomb, Phillip J.

    2011-01-01

    This study took advantage of the subsecond temporal resolution of ERPs to investigate mechanisms underlying age- and performance-related differences in working memory. Young and old subjects participated in a verbal n-back task with three levels of difficulty. Each group was divided into high and low performers based on accuracy under the 2-back condition. Both old subjects and low-performing young subjects exhibited impairments in preliminary mismatch/match detection operations (indexed by the anterior N2 component). This may have undermined the quality of information available for the subsequent decision-making process (indexed by the P3 component), necessitating the appropriation of more resources. Additional anterior and right hemisphere activity was recruited by old subjects. Neural efficiency and the capacity to allocate more resources to decision-making differed between high and low performers in both age groups. Under low demand conditions, high performers executed the task utilizing fewer resources than low performers (indexed by the P3 amplitude). As task requirements increased, high-performing young and old subjects were able to appropriate additional resources to decision-making, whereas their low-performing counterparts allocated fewer resources. Higher task demands increased utilization of processing capacity for operations other than decision-making (e.g., sustained attention) that depend upon a shared pool of limited resources. As demands increased, all groups allocated additional resources to the process of sustaining attention (indexed by the posterior slow wave). Demands appeared to have exceeded capacity in low performers, leading to a reduction of resources available to the decision-making process, which likely contributed to a decline in performance. PMID:20617886

  16. Event-related theta activity reflects memory processes in pronoun resolution.

    PubMed

    Heine, Angela; Tamm, Sascha; Hofmann, Markus; Bösel, Rainer M; Jacobs, Arthur M

    2006-12-18

    A recent eye-tracking study reported a reverse effect of a noun's lexical frequency in the context of the resolution of coreferring pronouns. Investigating the neurophysiological basis of this effect, the present electroencephalographic study found differential patterns in theta activation when participants read pronouns referring to nouns of different frequency classes. Evoked theta power after pronoun onset increased with the frequency of the critical noun. This finding suggests differential load on memory resources depending on the nouns' frequency. Elevated attention promoting memory encoding for low-frequency words is assumed to facilitate the resolution of pronouns. Location of sources of differential theta activity in the parahippocampal region is accounted for by its role in an association network that mediates memory processes. PMID:17179854

  17. Black phosphorus nonvolatile transistor memory

    NASA Astrophysics Data System (ADS)

    Lee, Dain; Choi, Yongsuk; Hwang, Euyheon; Kang, Moon Sung; Lee, Seungwoo; Cho, Jeong Ho

    2016-04-01

    We demonstrated nanofloating gate transistor memory devices (NFGTMs) using mechanically-exfoliated few-layered black phosphorus (BP) channels and gold nanoparticle (AuNPs) charge trapping layers. The resulting BP-NFGTMs exhibited excellent memory performances, including the five-level data storage, large memory window (58.2 V), stable retention (104 s), and cyclic endurance (1000 cycles).We demonstrated nanofloating gate transistor memory devices (NFGTMs) using mechanically-exfoliated few-layered black phosphorus (BP) channels and gold nanoparticle (AuNPs) charge trapping layers. The resulting BP-NFGTMs exhibited excellent memory performances, including the five-level data storage, large memory window (58.2 V), stable retention (104 s), and cyclic endurance (1000 cycles). Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr02078j

  18. Cyclic Nucleotide-Gated Channels, Calmodulin, Adenylyl Cyclase, and Calcium/Calmodulin-Dependent Protein Kinase II Are Required for Late, but Not Early, Long-Term Memory Formation in the Honeybee

    ERIC Educational Resources Information Center

    Matsumoto, Yukihisa; Sandoz, Jean-Christophe; Devaud, Jean-Marc; Lormant, Flore; Mizunami, Makoto; Giurfa, Martin

    2014-01-01

    Memory is a dynamic process that allows encoding, storage, and retrieval of information acquired through individual experience. In the honeybee "Apis mellifera," olfactory conditioning of the proboscis extension response (PER) has shown that besides short-term memory (STM) and mid-term memory (MTM), two phases of long-term memory (LTM)…

  19. Vertical bloch line memory

    NASA Technical Reports Server (NTRS)

    Katti, R.; Wu, J.; Stadler, H.

    1990-01-01

    Vertical Bloch Line (VBL) memory is a recently conceived, integrated, solid-state, block-access, VLSI memory which offers the potential of 1Gbit/sq cm real storage density, gigabit per second data rates, and sub-millisecond average access times simultaneously at relatively low mass, volume, and power values when compared to alternative technologies. VBL's are micromagnetic structures within magnetic domain walls which can be manipulated using magnetic fields from integrated conductors. The presence or absence of VBL pairs are used to store binary information. At present, efforts are being directed at developing a single-chip memory using 25Mbit/sq cm technology in magnetic garnet material which integrates, at a single operating point, the writing, storage, reading, and amplification functions needed in a memory. This paper describes the current design architecture, functional elements, and supercomputer simulation results which are used to assist the design process. The current design architecture uses three metal layers, two ion implantation steps for modulating the thickness of the magnetic layer, one ion implantation step for assisting propagation in the major line track, one NiFe soft magnetic layer, one CoPt hard magnetic layer, and one reflective Cr layer for facilitating magneto-optic observation of magnetic structure. Data are stored in a series of elongated magnetic domains, called stripes, which serve as storage sites for arrays of VBL pairs. The ends of these stripes are placed near conductors which serve as VBL read/write gates. A major line track is present to provide a source and propagation path for magnetic bubbles. Writing and reading, respectively, are achieved by converting magnetic bubbles to VBL's and vice versa. The output function is effected by stretching a magnetic bubble and detecting it magnetoresistively. Experimental results from the past design cycle created four design goals for the current design cycle. First, the bias field ranges

  20. [Neuroanatomical Networks Supporting Memory and Their Relation to Amnesia; a View from the Thalamus].

    PubMed

    Nishio, Yoshiyuki; Mori, Etsuro

    2015-12-01

    The anterior and mediodorsal thalamic nuclei form neuroanatomical networks supporting memory along with the mammillary body, medial temporal structures, prefrontal cortices and posterior cingulate cortex. In this review article, we discuss human diencephalic amnesic syndromes, including Wernicke-Korsakoff syndrome and amnesia associated with thalamic infarcts, and animal neuropsychological studies from a neuroanatomical network perspective. In addition, we suggest future research directions for understanding the functional roles of the anterior and mediodorsal thalamic nuclei in memory function based on findings from recent animal studies. PMID:26618762