Search results for "memory"
showing 10 items of 2004 documents
Machine Learning Methods for One-Session Ahead Prediction of Accesses to Page Categories
2004
This paper presents a comparison among several well-known machine learning techniques when they are used to carry out a one-session ahead prediction of page categories. We use records belonging to 18 different categories accessed by users on the citizen web portal Infoville XXI. Our first approach is focused on predicting the frequency of accesses (normalized to the unity) corresponding to the user’s next session. We have utilized Associative Memories (AMs), Classification and Regression Trees (CARTs), Multilayer Perceptrons (MLPs), and Support Vector Machines (SVMs). The Success Ratio (SR) averaged over all services is higher than 80% using any of these techniques. Nevertheless, given the …
Qualitative analysis of the Best Possible Self intervention: Underlying mechanisms that influence its efficacy.
2019
BackgroundThe Best Possible Self is a Positive Psychology Intervention which asks participants to write down about themselves in their best possible future. Previous studies have shown its efficacy to enhance wellbeing, but the mechanisms that underlie its efficacy are still unknown.ObjectiveThe aim of this study was to analyze the content of the essays of the BPS intervention and to examine how this content was related to the efficacy of the intervention to increase positive affect.MethodParticipants (N = 78) were randomized to either the Best Possible Self condition, or one of two variants of the intervention: one's best self in the present, and one's best self in the past. Qualitative an…
Three-page encoding and complexity theory for spatial graphs
2004
We construct a series of finitely presented semigroups. The centers of these semigroups encode uniquely up to rigid ambient isotopy in 3-space all non-oriented spatial graphs. This encoding is obtained by using three-page embeddings of graphs into the product of the line with the cone on three points. By exploiting three-page embeddings we introduce the notion of the three-page complexity for spatial graphs. This complexity satisfies the properties of finiteness and additivity under natural operations.
Transient oligemia is associated with long-term changes in binding densities of cortical inhibitory GABAA receptors in the rat brain
2009
Recently, we could demonstrate in rats that a short transient oligemic period of only 20-minute duration, induced by systemic hypotension, resulted in a transient decline of spatial memory capacities without any histological damage over a subsequent period of 6 months. In our present study, we checked for more subtle alterations within the highly vulnerable hippocampal CA1 subfield using quantification of neuronal cell density and semi-quantitative analysis of the ischemia-sensitive protein MAP2. Since hippocampal excitatory and inhibitory neurotransmitter receptors are crucially involved in spatial memory processes, quantitative in vitro receptor autoradiography was performed using [(3)H]M…
MEMORIA DE TRABAJO EN NIÑOS DE EDUCACIÓN INFANTIL CON Y SIN BAJO RENDIMIENTO MATEMÁTICO
2014
Abstract:This study aims to explore working memory in preschool children with and without low mathematical performance. The sample consisted of 255 children aged 5-6 years, to whom were administered neuropsychological tests of working memory and TEDI-MATH to estimate the mathematical performance. The results highlight the capacity of verbal working memory to significantly differentiate groups of children with and without problems in 8 of the 9 analyzed mathematical domains. This factor together with visuospatial working memory differentiate the group of children at risk for mathematical learning disabilities.Keywords: working memory, preschool, math performance, mathematics learning disabil…
Dissociable contributions of left and right dorsolateral prefrontal cortex in planning.
2010
It is well established that the mid-dorsolateral prefrontal cortex (dlPFC) plays a critical role in planning. Neuroimaging studies have yielded predominantly bilateral dlPFC activations, but the existence and nature of functionally specific contributions of left and right dlPFC have remained elusive. In recent experiments, 2 independent parameters have been identified which substantially determine planning: 1) the degree of interdependence between consecutive steps (search depth) and 2) the degree to which the configuration of the goal state renders the order of single steps either clearly evident or ambiguous (goal hierarchy). Thus, search depth affects the actual mental generation and eva…
Macrophage migration inhibitory factor is critically involved in basal and fluoxetine-stimulated adult hippocampal cell proliferation and in anxiety,…
2011
Intensive research is devoted to unravel the neurobiological mechanisms mediating adult hippocampal neurogenesis, its regulation by antidepressants, and its behavioral consequences. Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine that is expressed in the CNS, where its function is unknown. Here, we show, for the first time, the relevance of MIF expression for adult hippocampal neurogenesis. We identify MIF expression in neurogenic cells (in stem cells, cells undergoing proliferation, and in newly proliferated cells undergoing maturation) in the subgranular zone of the rodent dentate gyrus. A causal function for MIF in cell proliferation was shown using genetic (M…
Psychological experience of patients 3 months after a stay in the intensive care unit: A descriptive and qualitative study.
2015
Abstract Purpose The purpose was to describe psychological experiences of patients 3 months after a stay in the intensive care unit (ICU) using qualitative methods. Methods Twenty patients underwent clinical interview lasting 1 hour and completed the Impact of Event Scale—Revised and Hospital Anxiety and Depression questionnaires. All interviews were recorded and coded using thematic analysis. Results All patients (100%) reported that they could not remember their ICU stay; half reported confused memories (50%) or disorientation (50%). Negatives memories were also reported (20%-45%), namely, pain, distress, sleep difficulties, noise, fear, feeling of abandonment; 20% reported positive memor…
Funcionamiento ejecutivo y rendimiento matemático: un estudio longitudinal
2016
El objetivo del presente estudio longitudinal consistió en examinar el poder predictivo de las funciones ejecutivas de inhibición y memoria de trabajo (MT) evaluadas en Educación Infantil (T1) sobre los aspectos formales e informales del rendimiento matemático en 2º de Educación Primaria (T2). La muestra inicial estuvo conformada por 209 preescolares de 5 a 6 años, de los que un 86.12 % de los sujetos volvieron a ser evaluados en el T2 (7-8 años). En el T1, se administraron seis tareas neuropsicológicas relacionadas con las funciones ejecutivas de inhibición y MT verbal y visoespacial. En el T2, se aplicó la batería TEMA-3 (Gingsburg y Baroody, 2003) para evaluar diferentes aspectos relacio…
Gaming is related to enhanced working memory performance and task-related cortical activity
2017
Gaming experience has been suggested to lead to performance enhancements in a wide variety of working memory tasks. Previous studies have, however, mostly focused on adult expert gamers and have not included measurements of both behavioral performance and brain activity. In the current study, 167 adolescents and young adults (aged 13–24 years) with different amounts of gaming experience performed an n-back working memory task with vowels, with the sensory modality of the vowel stream switching between audition and vision at random intervals. We studied the relationship between self-reported daily gaming activity, working memory (n-back) task performance and related brain activity measured u…