scholarly journals Improving the integrative memory model by integrating the temporal dynamics of memory

2019 ◽  
Vol 42 ◽  
Author(s):  
Jonathan Curot ◽  
Emmanuel J. Barbeau

Abstract Despite highlighting the role of the attribution system and proposing a coherent large-scale architecture of declarative memory, the integrative memory model would be more “integrative” if the temporal dynamics of the interactions between its components was clarified. This is necessary to make predictions in patients with brain injury and hypothesize dissociations.

Neurosurgery ◽  
2017 ◽  
Vol 64 (CN_suppl_1) ◽  
pp. 288-289 ◽  
Author(s):  
Andrew Phillip Carlson ◽  
Mohammad Abbas ◽  
Rob Alunday ◽  
Fares Qeadank ◽  
C William Shuttleworth

Abstract INTRODUCTION Retrospective clinical data support a therapeutic effect of ketamine in suppression of CSD. Animal and slice data strongly support this targeted efficacy on CSD. We present the results of the first prospective clinical trial testing the role of ketamine used for clinical sedation on occurrence of CSD after brain injury. METHODS 10 subjects with aneurysmal subarachnoid hemorrhage (SAH) or severe traumatic brain injury (TBI) or were recruited. A 1 × 6 ECog strip was placed at the time of craniotomy and subjects were then placed on a randomized alternating 6 hour schedule of ketamine or other sedation agent. Ketamine dose was adjusted to clinical effect and left at a subanesthetic basal dose if no sedation was required (0.1mg/kg/h.) CSD was scored using standard criteria, blinded to ketamine dosing. Occurrence of CSD was then compared to the hourly dose of ketamine to determine the effect of ketamine on CSD occurrence. RESULTS >Successful ECog recordings were obtained in all 10 subjects 8 with SAH and 2 with TBI. There was a total of 1642 hours of observations with adequate ECog 833 off ketamine and 809 on ketamine. Hours on doses of less than 1.15 mg/kg/h were associated with a highly significant increased risk of CSD compared with hours on doses of 1.15 mg/kg/h or more (OR = 13.838, 95% CI = 1.99-1000). A decrease of 0.15 mg/kg/h in dose was found to be associated with two-fold increase in the odds of CSDs (OR = 1.973, 95% CI = 1.265-3.503). There was no significant effect of ketamine on the mean duration of depression after CSD (F = 2.62, P = 0.11). CONCLUSION Ketamine effectively inhibits CSD after acute neurologic injury (SAH and TBI) in a dose dependent fashion. These data also demonstrate the feasibility of using CSD as a surrogate measure in future studies prior to large-scale studies of CSD directed therapy on outcome.


2013 ◽  
Author(s):  
Elisabeth J. Ploran ◽  
Ericka Rovira ◽  
James C. Thompson ◽  
Raja Parasuraman

2017 ◽  
Vol 13 (1) ◽  
pp. 4486-4494 ◽  
Author(s):  
G.El Damrawi ◽  
F. Gharghar

Cerium oxide in borate glasses of composition xCeO2·(50 − x)PbO·50B2O3 plays an important role in changing both microstructure and magnetic behaviors of the system. The structural role of CeO2 as an effective agent for cluster and crystal formation in borate network is clearly evidenced by XRD technique. Both structure and size of well-formed cerium separated clusters have an effective influence on the structural properties. The cluster aggregations are documented to be found in different range ordered structures, intermediate and long range orders are the most structures in which cerium phases are involved. The nano-sized crystallized cerium species in lead borate phase are evidenced to have magnetic behavior.  The criteria of building new specific borate phase enriched with cerium as ferrimagnetism has been found to keep the magnetization in large scale even at extremely high temperature. Treating the glass thermally or exposing it to an effective dose of ionized radiation is evidenced to have an essential change in magnetic properties. Thermal heat treatment for some of investigated materials is observed to play dual roles in the glass matrix. It can not only enhance alignment processes of the magnetic moment but also increases the capacity of the crystallite species in the magnetic phases. On the other hand, reverse processes are remarked under the effect of irradiation. The magnetization was found to be lowered, since several types of the trap centers which are regarded as defective states can be produced by effect of ionized radiation. 


e-Finanse ◽  
2018 ◽  
Vol 14 (4) ◽  
pp. 67-76
Author(s):  
Piotr Bartkiewicz

AbstractThe article presents the results of the review of the empirical literature regarding the impact of quantitative easing (QE) on emerging markets (EMs). The subject is of interest to policymakers and researchers due to the increasingly larger role of EMs in the world economy and the large-scale capital flows occurring after 2009. The review is conducted in a systematic manner and takes into consideration different methodological choices, samples and measurement issues. The paper puts the summarized results in the context of transmission channels identified in the literature. There are few distinct methodological approaches present in the literature. While there is a consensus regarding the direction of the impact of QE on EMs, its size and durability have not yet been assessed with sufficient precision. In addition, there are clear gaps in the empirical findings, not least related to relative underrepresentation of the CEE region (in particular, Poland).


2020 ◽  
Author(s):  
Rui Sun ◽  
Disa Sauter

Getting old is generally seen as unappealing, yet aging confers considerable advantages in several psychological domains (North & Fiske, 2015). In particular, older adults are better off emotionally than younger adults, with aging associated with the so-called “age advantages,” that is, more positive and less negative emotional experiences (Carstensen et al., 2011). Although the age advantages are well established, it is less clear whether they occur under conditions of prolonged stress. In a recent study, Carstensen et al (2020) demonstrated that the age advantages persist during the COVID-19 pandemic, suggesting that older adults are able to utilise cognitive and behavioural strategies to ameliorate even sustained stress. Here, we build on Carstensen and colleagues’ work with two studies. In Study 1, we provide a large-scale test of the robustness of Carstensen and colleagues’ finding that older individuals experience more positive and less negative emotions during the COVID-19 pandemic. We measured positive and negative emotions along with age information in 23,629 participants in 63 countries in April-May 2020. In Study 2, we provide a comparison of the age advantages using representative samples collected before and during the COVID-19 pandemic. We demonstrate that older people experience less negative emotion than younger people during the prolonged stress of the COVID-19 pandemic. However, the advantage of older adults was diminished during the pandemic, pointing to a likely role of older adults use of situation selection strategies (Charles, 2010).


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