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Long-term Retention (long-term + retention)
Selected AbstractsPrognostic Factors Affecting Long-Term Retention of Topiramate in Patients with Chronic EpilepsyEPILEPSIA, Issue 3 2000S. D. Lhatoo Summary: Purpose: To determine the long-term retention rate of topiramate (TPM) therapy in patients with chronic epilepsy and to identify the relevant prognostic factors that influence retention. Methods: All patients with chronic epilepsy (n = 393) prescribed TPM between October 1, 1995, and December 31, 1998, at a tertiary referral centre for epilepsy were analysed. The retention rate for TPM was calculated by using Kaplan-Meier survival analysis, and the prognostic factors influencing retention were analysed by using Cox regression. Results: Of patients prescribed TPM, 30% continued taking the drug beyond 3 years. Discontinuation was mainly due to adverse events and lack of efficacy. Use of more than one new concurrent antiepileptic drug (AED) and lower maximal daily doses were more likely to result in treatment discontinuation due to adverse events. Older age at onset of epilepsy, a history of having previously taken more than one new AED [lamotrigine (LTG), gabapentin (GBP), or vigabatrin (VGB)], and lower maximal daily doses were more likely to lead to discontinuation due to lack of efficacy. Conclusions: A third of patients with chronic epilepsy started on TPM therapy will continue on treatment for >3 years. Absence of learning disabilities, late age at onset of seizures, previous use of more than one new AED, two or more concurrent AED use, and low maximal daily doses of TPM are more likely to result in discontinuation of medication. These factors should be taken into account when considering the use of TPM for the treatment of chronic epilepsy. [source] Long-term retention of coded wire tags in juvenile Arctic charr Salvelinus alpinusFISHERIES MANAGEMENT & ECOLOGY, Issue 3 2006I. KOLARI Abstract, A hatchery experiment was organised to find out if the high loss rate of coded wire tags, noticed in connection with an Arctic charr Salvelinus alpinus (L.) restocking programme, was size-dependent and also to test head moulds for future taggings. Six moulds made by Northwest Marine Technology Inc. and five moulds made at the Finnish Game and Fisheries Research Institute were used. A total of 100 charr were tagged with standard-length coded wire tags using each mould. One-summer old charr at tagging were held for 534 days and two-summer old charr for 320 days. The tag loss rate varied between 0% and 54% and was negatively related to the size of the charr at tagging. The high loss rate was connected with the poor alignment of some moulds, such that a large proportion of the tags were located in the nasal cavity instead of the nasal cartilage. Testing of the moulds and careful grading of the fish for tagging is emphasised, especially if Arctic charr smaller than 20 g in weight are to be tagged. [source] Empirical tests of the functional significance of amygdala-based modulation of hippocampal representations: evidence for multiple memory consolidation pathwaysEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 5 2007Robert J. McDonald Abstract This series of experiments evaluated the effects of amygdala damage on the acquisition and long-term retention of variants of the water task, and tested the hypothesis that the amygdala is an essential neural system for consolidation of hippocampal memories. In Experiment 1, rats with large, neurotoxic lesions of the amygdala (AMYG) showed normal acquisition on the standard spatial version of the water task, as well as normal retention and decay rate profiles on the 24-h and 30-day retention probes. In Experiment 2, AMYG rats showed normal one-trial place learning abilities and could retain this one-trial information over a 24 h delay. Experiment 3 showed that the amygdala lesions used in this study were functionally significant because AMYG rats, from Experiment 2, showed impairments in a discriminative fear conditioning to context paradigm. Experiment 4 was a critical test of the idea that the amygdala is a decisive locus for consolidation of hippocampal memories. AMYG rats were trained to sub-asymptotic levels of performance on the standard version of the water task. Following each training session, the subjects were given a post-training peripheral injection of d -amphetamine. A probe test revealed that normal subjects and AMYG rats showed similar post-training memory improvement effects. Taken together, the results show that hippocampal memory consolidation processes do not require amygdala modulation. Arguments for an alternative view are presented suggesting that there are multiple memory consolidation pathways, one of which may depend on amygdala neural circuitry. [source] Characterizing nitrogen dynamics, retention and transport in a tropical rainforest stream using an in situ15N additionFRESHWATER BIOLOGY, Issue 1 2002Jeffrey L. Merriam 1.,This study was part of the Lotic Intersite Nitrogen eXperiment (LINX); a series of identical 15NH4 tracer additions to streams throughout North America. 15NH4Cl was added at tracer levels to a Puerto Rican stream for 42 days. Throughout the addition, and for several weeks afterwards, samples were collected to determine the uptake, retention and transformation pathways of nitrogen in the stream. 2.,Ammonium uptake was very rapid. Nitrification was immediate, and was a very significant transformation pathway, accounting for over 50% of total NH4 uptake. The large fraction of NH4 uptake accounted for by nitrification (a process that provides energy to the microbes involved) suggests that energy limitation of net primary production, rather than N limitation, drives N dynamics in this stream. 3.,There was a slightly increased 15N label in dissolved organic nitrogen (DON) the day after the 15NH4 addition was stopped. This DO15N was < 0.02% of DON concentration in the stream water at the time, suggesting that nearly all of the DON found in-stream is allochthonous, or that in-stream DON production is very slow. 4.,Leptophlebiidae and Atya appear to be selectively feeding or selectively assimilating a very highly labelled fraction of the epilithon, as the label found in the consumers became much higher than the label found in the food source. 5.,A large spate (>20-fold increase in discharge) surprisingly removed only 37% of in-stream fine benthic organic matter (FBOM), leaves and epilithon. The fraction that was washed out travelled downstream a long distance (>220 m) or was washed onto the stream banks. 6.,While uptake of 15NH4 was very rapid, retention was low. Quebrada Bisley retained only 17.9% of the added 15N after 42 days of 15N addition. Most of this was in FBOM and epilithon. Turnover rates for these pools were about 3 weeks. The short turnover times of the primary retention pools suggest that long-term retention (>1 month) is minimal, and is probably the result of N incorporation into shrimp biomass, which accounted for < 1% of the added 15N. [source] Neural correlates of the spacing effect in explicit verbal semantic encoding support the deficient-processing theoryHUMAN BRAIN MAPPING, Issue 4 2010Daniel E. Callan Abstract Spaced presentations of to-be-learned items during encoding leads to superior long-term retention over massed presentations. Despite over a century of research, the psychological and neural basis of this spacing effect however is still under investigation. To test the hypotheses that the spacing effect results either from reduction in encoding-related verbal maintenance rehearsal in massed relative to spaced presentations (deficient processing hypothesis) or from greater encoding-related elaborative rehearsal of relational information in spaced relative to massed presentations (encoding variability hypothesis), we designed a vocabulary learning experiment in which subjects encoded paired-associates, each composed of a known word paired with a novel word, in both spaced and massed conditions during functional magnetic resonance imaging. As expected, recall performance in delayed cued-recall tests was significantly better for spaced over massed conditions. Analysis of brain activity during encoding revealed that the left frontal operculum, known to be involved in encoding via verbal maintenance rehearsal, was associated with greater performance-related increased activity in the spaced relative to massed condition. Consistent with the deficient processing hypothesis, a significant decrease in activity with subsequent episodes of presentation was found in the frontal operculum for the massed but not the spaced condition. Our results suggest that the spacing effect is mediated by activity in the frontal operculum, presumably by encoding-related increased verbal maintenance rehearsal, which facilitates binding of phonological and word level verbal information for transfer into long-term memory. Hum Brain Mapp, 2010. © 2009 Wiley-Liss, Inc. [source] Verbal memory improved by D -amphetamine: influence of the testing effectHUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 5 2010Inge Zeeuws Abstract Objective The improvement of long-term retention of verbal memory after an acute administration of D -amphetamine in recall and recognition tasks has been ascribed to an influence of the drug on memory consolidation. Because recent research has demonstrated that intermediate testing is of overriding importance for retention, we investigated whether D -amphetamine modulates the repeated testing effect in verbal long-term recognition. Method Forty men participated in two double blind placebo controlled studies. In Experiment 1, we manipulated the number of recognition tests and in Experiment 2, we compared repeated with nonrepeated testing of the same items. Results Drug effects were observed on delayed tests only, leaving immediate recognition unaffected. Number of intermediate recognition tests and repeated testing of the same items were not affected by D -amphetamine. Conclusions We conclude that the D -amphetamine memory enhancement is not related to the testing effect. This result supports that D -amphetamine modulates other aspects of the consolidation process, probably related to context effects. Copyright © 2010 John Wiley & Sons, Ltd. [source] Verbal memory performance improved via an acute administration of D -amphetamineHUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 5 2007Inge Zeeuws Abstract Background An improved long-term retention of verbal memory was observed after an acute D -amphetamine administration. It was proposed that D -amphetamine modulates consolidation, but a possible drug effect on retrieval could not be rejected. Objectives We want to provide additional support for the consolidation hypothesis, and investigate whether an influence on intervening retrieval can be refuted. Methods Thirty-six male paid volunteers participated in a double blind, counterbalanced, placebo-controlled design in which the number of intermediate free recall tests was manipulated. Results A significant D -amphetamine facilitation effect on recall performance emerged 1 h and 1 day after list learning. In line with the consolidation hypothesis, no effect was found on immediate tests. Importantly, the number of intermediate retrievals did not affect the magnitude of the drug effect, suggesting that the D -amphetamine facilitation effect is independent of retrieval. Conclusion The D -amphetamine facilitation effect on verbal memory does not involve a modulation of the initial encoding or short-term memory (STM) processes. Moreover, the drug does not enhance long-term retention by acting on intervening retrieval processes. The current findings are in line with the conjecture of an involvement of the consolidation process in the D -amphetamine facilitation effect on verbal memory in healthy humans. Copyright © 2007 John Wiley & Sons, Ltd. [source] The Effect of Frequency of Input-Enhancements on Word Learning and Text ComprehensionLANGUAGE LEARNING, Issue 2 2007Susanne Rott Research on second language lexical development during reading has found positive effects for word frequency, the provision of glosses, and elaborative word processing. However, findings have been inconclusive regarding the effect of such intervention tasks on long-term retention. Likewise, few studies have looked at the cumulative effect of interventions on word learning or text comprehension. This investigation sought to assess the effect of increased frequency of target words (TWs) comparing lexical gain of words that occurred once (F1) or four times (F4) in the input passage. The study further investigated the combined effect of frequency (F4) and semantic or visual enhancements. It compared the following reading conditions: (a) TWs were glossed four times in the text (four-gloss: 4G); (b) TWs were first glossed, then retrieved in the first language, and bolded twice (gloss-retrieval: GR); and (c) TWs were first glossed and then bolded three times (gloss-bolding: GB). In addition, the study assessed the effect of these interventions on long-term retention (4,6 weeks) of lexical knowledge and on text comprehension. Findings revealed that the GR and 4G reading conditions resulted in more productive word gain than the GB condition or when readers encountered a TW only once. Repeated visual enhancements seemed to have no effect on strengthening word encoding. The comprehension of main ideas was highest when the TW was glossed four times followed by the gloss-bolding reading condition and the gloss-retrieval task. [source] Levodopa: Faster and better word learning in normal humansANNALS OF NEUROLOGY, Issue 1 2004Stefan Knecht MD Dopamine is a potent modulator of learning and has been implicated in the encoding of stimulus salience. Repetition, however, as required for the acquisition and reacquisition of sensorimotor or cognitive skills (e.g., in aphasia therapy), decreases salience. We here tested whether increasing brain levels of dopamine during repetitive training improves learning success. Forty healthy humans took 100mg of the dopamine precursor levodopa or placebo daily for 5 days in a randomized double-blind and parallel-group design. Ninety minutes later on each day, subjects were trained on an artificial vocabulary using a high-frequency repetitive approach. Levodopa significantly enhanced the speed, overall success, and long-term retention of novel word learning in a dose-dependent manner. These findings indicate new ways to potentiate learning in a variety of domains if conventional training alone fails. [source] Using tests to enhance 8th grade students' retention of U.S. history facts,,APPLIED COGNITIVE PSYCHOLOGY, Issue 6 2009Shana K. Carpenter Laboratory studies show that retention of information can be powerfully enhanced through testing, but evidence for their utility to promote long-term retention of course information is limited. We assessed 8th grade students' retention of U.S. history facts. Facts were reviewed after 1 week, 16 weeks or not reviewed at all. Some facts were reviewed by testing (Who assassinated president Abraham Lincoln?) followed by feedback (John Wilkes Booth), while others were re-studied. Nine months later, all students received a test covering all of the facts. Facts reviewed through testing were retained significantly better than facts reviewed through re-studying, and nearly twice as well as those given no review. The best retention occurred for facts that were reviewed by testing after a 16-week time interval. Although the gain in item was numerically small, due to floor effects, these results support the notion that testing can enhance long-term retention of course knowledge. Copyright © 2008 John Wiley & Sons, Ltd. [source] Does adaptive training work?APPLIED COGNITIVE PSYCHOLOGY, Issue 2 2009Claudia Metzler-Baddeley People intuitively alter the allocation of study time between items of varying difficulty, and such adaptive learning methods are widely used in education and in commercially available memory training programs. We investigated the effectiveness of a computer-based adaptive learning system that utilises spacing and repetition effects by presenting difficult items with short gaps to establish fast learning, and easy items with long intervals to optimise long-term retention. The immediate and delayed effects of adaptive training on cued recall were investigated relative to a control condition of non-adaptive, random spacing. Adaptive training produced significantly higher immediate and delayed recall rates than random spacing. These results encourage the use of adaptive training in education and rehabilitation. Copyright © 2008 John Wiley & Sons, Ltd. [source] A tissue-engineered suburethral sling in an animal model of stress urinary incontinenceBJU INTERNATIONAL, Issue 4 2005Tracy W. Cannon OBJECTIVE To create and evaluate the functional effects of a tissue-engineered sling in an animal model of stress urinary incontinence (SUI). MATERIALS AND METHODS Twenty female Sprague-Dawley rats were divided into four equal groups: a control group (C) had no intervention before the leak-point pressure (LPP) was measured; a denervated group (D) had bilateral proximal sciatic nerve transection (PSNT) and periurethral dissection with no sling placed; group S had concomitant bilateral PSNT and a suburethral sling of small intestinal submucosa (SIS) placed; and group (M) had concomitant bilateral PSNT with implantation of a tissue-engineered sling. The suburethral sling was placed via a transabdominal approach with the sling sutured to the pubic bone. Tissue-engineered slings were prepared with muscle-derived cells obtained via the pre-plate technique and subsequently seeded for 2 weeks on a SIS scaffold. Suburethral slings were implanted 2 weeks before LPP testing, using the vertical-tilt method. RESULTS Surgically placing a suburethral sling is feasible in the female rat, with few complications. LPPs from both sling groups (S and M) were not significantly different from untreated controls (C). The S, M and C groups all had significantly higher LPPs than group D. Importantly, no rat from either sling group (S and M) had signs of urinary retention. CONCLUSIONS Placing tissue-engineered slings in an animal model of SUI resulted in LPP values that were not significantly different from those in untreated control or SIS (S) groups. These data show that incorporating muscle stem cells into SIS slings does not adversely alter the advantageous mechanical properties of the SIS sling in a model of SUI, and provide the basis for future functional studies of tissue-engineered sling materials with long-term retention. [source] Emotional arousal enhances declarative memory in patients with Alzheimer's diseaseACTA NEUROLOGICA SCANDINAVICA, Issue 6 2007C. Satler Objective,,, To verify whether the long-term retention of an emotionally arousing story is stronger than the retention of a neutral story, and the enhancing effects of emotional arousal on declarative memory in Alzheimer's disease (AD) patients. Method,,, Twenty subjects (10 with AD and 10 controls matched for age and educational level) were studied. After the audiovisual presentation (neutral story), the subjects rated the narrative's emotionality. Later, they answered a multiple-choice questionnaire about the stories. Two weeks later, they watched the emotionally arousing story. Results,,, Subjects who watched the emotionally arousing story assigned a score of emotionality higher than the subjects in the neutral group (P = 0.023). In addition, the participants remembered more details of the arousing story, and had a higher score in the questionnaire (P < 0.001). Conclusions,,, We demonstrated that an emotionally arousing content enhances long-term declarative memory in AD. Furthermore, present finding supports the use of this instrument for clinical and research purposes. [source] | |||||||||||||