scholarly journals Mental Mechanisms for Topics Identification

2014 ◽  
Vol 2014 ◽  
pp. 1-11
Author(s):  
Louis Massey

Topics identification (TI) is the process that consists in determining the main themes present in natural language documents. The current TI modeling paradigm aims at acquiring semantic information from statistic properties of large text datasets. We investigate the mental mechanisms responsible for the identification of topics in a single document given existing knowledge. Our main hypothesis is that topics are the result of accumulated neural activation of loosely organized information stored in long-term memory (LTM). We experimentally tested our hypothesis with a computational model that simulates LTM activation. The model assumes activation decay as an unavoidable phenomenon originating from the bioelectric nature of neural systems. Since decay should negatively affect the quality of topics, the model predicts the presence of short-term memory (STM) to keep the focus of attention on a few words, with the expected outcome of restoring quality to a baseline level. Our experiments measured topics quality of over 300 documents with various decay rates and STM capacity. Our results showed that accumulated activation of loosely organized information was an effective mental computational commodity to identify topics. It was furthermore confirmed that rapid decay is detrimental to topics quality but that limited capacity STM restores quality to a baseline level, even exceeding it slightly.

2019 ◽  
Vol 29 (3) ◽  
pp. 438-448
Author(s):  
Mei-yung Leung ◽  
Chendi Wang ◽  
Timothy CY Kwok

Supporting facilities (SF) including handrails, signage, finishes, furniture and recreational facilities facilitate the daily life of older persons. Memory loss is one of the most common signs of dementia affecting the daily life of older persons. Therefore, they may need special SF in residential homes. In order to improve the quality of daily life of older people with dementia, this study aims to investigate the effects of SF on the memory loss of those living in care and attention (C&A) homes. A questionnaire survey was conducted among elderly C&A home residents aged 65 and above in Hong Kong. A Supporting Facilities-Memory Loss model was established based on correlation and regression analyses. The model confirmed the following: (1) none of the SF items affects long-term memory loss; (2) satisfaction with signage, finishes and furniture leads to a reduction of short-term memory loss; (3) satisfaction with handrails, signage and finishes enhances spatial memory and (4) satisfaction with the location of signage reduces time confusion. Practical recommendations are proposed, including using large and well-placed signage with pictograms and icons, avoiding the removal and modification of furniture, enhancing colour contrasts between different functional rooms, installing handrails with a consideration for orientation strategies, and so on.


2016 ◽  
Vol 39 ◽  
Author(s):  
Mary C. Potter

AbstractRapid serial visual presentation (RSVP) of words or pictured scenes provides evidence for a large-capacity conceptual short-term memory (CSTM) that momentarily provides rich associated material from long-term memory, permitting rapid chunking (Potter 1993; 2009; 2012). In perception of scenes as well as language comprehension, we make use of knowledge that briefly exceeds the supposed limits of working memory.


2020 ◽  
Vol 29 (4) ◽  
pp. 710-727
Author(s):  
Beula M. Magimairaj ◽  
Naveen K. Nagaraj ◽  
Alexander V. Sergeev ◽  
Natalie J. Benafield

Objectives School-age children with and without parent-reported listening difficulties (LiD) were compared on auditory processing, language, memory, and attention abilities. The objective was to extend what is known so far in the literature about children with LiD by using multiple measures and selective novel measures across the above areas. Design Twenty-six children who were reported by their parents as having LiD and 26 age-matched typically developing children completed clinical tests of auditory processing and multiple measures of language, attention, and memory. All children had normal-range pure-tone hearing thresholds bilaterally. Group differences were examined. Results In addition to significantly poorer speech-perception-in-noise scores, children with LiD had reduced speed and accuracy of word retrieval from long-term memory, poorer short-term memory, sentence recall, and inferencing ability. Statistically significant group differences were of moderate effect size; however, standard test scores of children with LiD were not clinically poor. No statistically significant group differences were observed in attention, working memory capacity, vocabulary, and nonverbal IQ. Conclusions Mild signal-to-noise ratio loss, as reflected by the group mean of children with LiD, supported the children's functional listening problems. In addition, children's relative weakness in select areas of language performance, short-term memory, and long-term memory lexical retrieval speed and accuracy added to previous research on evidence-based areas that need to be evaluated in children with LiD who almost always have heterogenous profiles. Importantly, the functional difficulties faced by children with LiD in relation to their test results indicated, to some extent, that commonly used assessments may not be adequately capturing the children's listening challenges. Supplemental Material https://doi.org/10.23641/asha.12808607


2010 ◽  
Vol 24 (4) ◽  
pp. 249-252 ◽  
Author(s):  
Márk Molnár ◽  
Roland Boha ◽  
Balázs Czigler ◽  
Zsófia Anna Gaál

This review surveys relevant and recent data of the pertinent literature regarding the acute effect of alcohol on various kinds of memory processes with special emphasis on working memory. The characteristics of different types of long-term memory (LTM) and short-term memory (STM) processes are summarized with an attempt to relate these to various structures in the brain. LTM is typically impaired by chronic alcohol intake but according to some data a single dose of ethanol may have long lasting effects if administered at a critically important age. The most commonly seen deleterious acute effect of alcohol to STM appears following large doses of ethanol in conditions of “binge drinking” causing the “blackout” phenomenon. However, with the application of various techniques and well-structured behavioral paradigms it is possible to detect, albeit occasionally, subtle changes of cognitive processes even as a result of a low dose of alcohol. These data may be important for the consideration of legal consequences of low-dose ethanol intake in conditions such as driving, etc.


1978 ◽  
Vol 10 (2) ◽  
pp. 141-148
Author(s):  
Mary Anne Herndon

In a model of the functioning of short term memory, the encoding of information for subsequent storage in long term memory is simulated. In the encoding process, semantically equivalent paragraphs are detected for recombination into a macro information unit. This recombination process can be used to relieve the limited storage capacity constraint of short term memory and subsequently increase processing efficiency. The results of the simulation give a favorable indication of the success for the use of cluster analysis as a tool to simulate the encoding function in the detection of semantically similar paragraphs.


2017 ◽  
Vol 14 (1) ◽  
pp. 172988141769231 ◽  
Author(s):  
Ning An ◽  
Shi-Ying Sun ◽  
Xiao-Guang Zhao ◽  
Zeng-Guang Hou

Visual tracking is a challenging computer vision task due to the significant observation changes of the target. By contrast, the tracking task is relatively easy for humans. In this article, we propose a tracker inspired by the cognitive psychological memory mechanism, which decomposes the tracking task into sensory memory register, short-term memory tracker, and long-term memory tracker like humans. The sensory memory register captures information with three-dimensional perception; the short-term memory tracker builds the highly plastic observation model via memory rehearsal; the long-term memory tracker builds the highly stable observation model via memory encoding and retrieval. With the cooperative models, the tracker can easily handle various tracking scenarios. In addition, an appearance-shape learning method is proposed to update the two-dimensional appearance model and three-dimensional shape model appropriately. Extensive experimental results on a large-scale benchmark data set demonstrate that the proposed method outperforms the state-of-the-art two-dimensional and three-dimensional trackers in terms of efficiency, accuracy, and robustness.


2005 ◽  
Vol 85 (1) ◽  
pp. 8-18 ◽  
Author(s):  
Jill C Heathcock ◽  
Anjana N Bhat ◽  
Michele A Lobo ◽  
James (Cole) Galloway

Abstract Background and Purpose. Infants born preterm differ in their spontaneous kicking, as well as their learning and memory abilities in the mobile paradigm, compared with infants born full-term. In the mobile paradigm, a supine infant's ankle is tethered to a mobile so that leg kicks cause a proportional amount of mobile movement. The purpose of this study was to investigate the relative kicking frequency of the tethered (right) and nontethered (left) legs in these 2 groups of infants. Subjects. Ten infants born full-term and 10 infants born preterm (<33 weeks gestational age, <2,500 g) and 10 comparison infants participated in the study. Methods. The relative kicking frequencies of the tethered and nontethered legs were analyzed during learning and short-term and long-term memory periods of the mobile paradigm. Results. Infants born full-term showed an increase in the relative kicking frequency of the tethered leg during the learning period and the short-term memory period but not for the long-term memory period. Infants born preterm did not show a change in kicking pattern for learning or memory periods, and consistently kicked both legs in relatively equal amounts. Discussion and Conclusion. Infants born full-term adapted their baseline kicking frequencies in a task-specific manner to move the mobile and then retained this adaptation for the short-term memory period. In contrast, infants born preterm showed no adaptation, suggesting a lack of purposeful leg control. This lack of control may reflect a general decrease in the ability of infants born preterm to use their limb movements to interact with their environment. As such, the mobile paradigm may be clinically useful in the early assessment and intervention of infants born preterm and at risk for future impairment.


1974 ◽  
Vol 38 (2) ◽  
pp. 495-501
Author(s):  
Gilbert B. Tunnell ◽  
Philippe R. Falkenberg

Manipulation of the context in a short-term memory paradigm produces changes in the ability to recognize the same material from long-term memory 24 hr. later. If immediate recall is accurate, later recognition is improved if this recall is conducted with the same context as occurred at learning. If immediate recall is completely inaccurate, later recognition is improved if this recall is conducted with different context than was present at learning. Short-term recall did not need to be accurate to transfer the learned nonsense trigrams to long-term memory. Manipulation of context 24 hr. after learning had no effect on recognition. Results are discussed in terms of the Waugh and Norman memory model, Tulving's encoding specificity hypothesis, and interference theory.


Author(s):  
Robert J. Biersner

Twenty-one U.S. Navy divers were given several standard visual tests, the Purdue Peg-board, the Bennett Hand Tool Dexterity Test, and the Wechsler Memory Scale while breathing air or 30% nitrous oxide. The results showed that visual function, fine and gross motor performance, and long-term memory were normal under nitrous oxide, while learning and short-term memory were significantly impaired. The subjective effects of breathing nitrous oxide were similar to those experienced during compressed air narcosis. The selective impairment of short-term memory suggests that divers might be able to perform useful work at depths deeper than those currently authorized, provided the tasks were well learned and practiced.


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