Vernon, David; Lloyd-Jones, Toby J
We present two experiments that examine the effects of colour transformation between study and test (from black and white to colour and vice versa, of from incorrectly coloured to correctly coloured and vice versa) on implicit and explicit measures of memory for diagnostically coloured natural objects (e.g., yellow banana). For naming and coloured-object decision (i.e., deciding whether an object is correctly coloured), there were shorter response times to correctly coloured-objects than to black-and-white and incorrectly coloured-objects. Repetition priming was equivalent for the different stimulus types. Colour transformation did not influence priming of picture naming, but for coloured-object decision priming was evident only for objects remaining the same from study to test. This was the case for both naming and coloured-object decision as study tasks. When participants were asked to consciously recognize objects that they had named or made coloured-object decisions to previously, whilst ignoring their colour, colour transformation reduced recognition efficiency. We discuss these results in terms of the flexibility of object representations that mediate priming and recognition.
Eich, TS; Murayama, K; Castel, AD; Knowlton, BJ
© 2014 Guilford Publications, Inc. While an awareness of age-related changes in memory may help older adults gain insight into their own cognitive abilities, it may also have a negative impact on memory performance through a mechanism of stereotype threat (ST). The consequence of ST is under-performance in abilities related to the stereotype. Here, we examined the degree to which explicit and implicit memory were affected by ST across a wide age-range. We found that explicit memory was affect...
Drosopoulos, Spyridon; Wagner, Ullrich; Born, Jan
Recognition memory is considered to be supported by two different memory processes, i.e., the explicit recollection of information about a previous event and an implicit process of recognition based on a contextual sense of familiarity. Both types of memory supposedly rely on distinct memory systems. Sleep is known to enhance the consolidation of…
Drosopoulos, Spyridon; Wagner, Ullrich; Born, Jan
Recognition memory is considered to be supported by two different memory processes, i.e., the explicit recollection of information about a previous event and an implicit process of recognition based on an acontextual sense of familiarity. Both types of memory supposedly rely on distinct memory systems. Sleep is known to enhance the consolidation of memories, with the different sleep stages affecting different types of memory. In the present study, we used the process-dissociation procedure to...
Raaijmakers, J.G.W.; Ohta, N.; Izawa, C.
Mathematical models of memory are useful for describing basic processes of memory in a way that enables generalization across a number of experimental paradigms. Models that have these characteristics do not just engage in empirical curve-fitting, but may also provide explanations for puzzling
Ladd, S L; Sommer, S A; LaBerge, S; Toscano, W
Previous studies have not demonstrated a consistent relationship between precursors to acetylcholine (ACh) and memory function in normal human subjects. This experiment (N = 80, college students) employed a double-blind mixed design to test the effect of phosphatidylcholine (PCh) on explicit memory. Dose of placebo and PCh was compared at two levels (10 and 25 g) as was time of testing postingestion (60 and 90 min). With 25 g of PCh, which supplies 3.75 g of choline, significant improvement in explicit memory, as measured by a serial learning task, was observed at 90 min postingestion and slight improvement was observed at 60 min postigestion. Further analyses indicated that this improvement may have been due to the responses of slow learners. This is the first study to test the relationship between a single dose of PCh and explicit memory on normal human subjects.
Becker, E.S.; Roth, W.T.; Andrich, M.; Margraf, J.
Two experiments were conducted to study selective memory bias favoring anxiety-relevant materials in patients with anxiety disorders. In the 1st experiment, 32 patients with generalized anxiety disorder (GAD), 30 with social phobia (speaking anxiety), and 31 control participants incidentally learned
Full Text Available It is well documented that explicit memory (e.g., recognition declines with age. In contrast, many argue that implicit memory (e.g., priming is preserved in healthy aging. For example, priming on tasks such as perceptual identification is often not statistically different in groups of young and older adults. Such observations are commonly taken as evidence for distinct explicit and implicit learning/memory systems. In this article we discuss several lines of evidence that challenge this view. We describe how patterns of differential age-related decline may arise from differences in the ways in which the two forms of memory are commonly measured, and review recent research suggesting that under improved measurement methods, implicit memory is not age-invariant. Formal computational models are of considerable utility in revealing the nature of underlying systems. We report the results of applying single and multiple-systems models to data on age effects in implicit and explicit memory. Model comparison clearly favours the single-system view. Implications for the memory systems debate are discussed.
Taankvist, Jakob Haahr; Srba, Jiri; Larsen, Kim Guldstrand
Timed analysis of real-time systems can be performed using continuous (symbolic) or discrete (explicit) techniques. The explicit state-space exploration can be considerably faster for models with moderately small constants, however, at the expense of high memory consumption. In the setting of timed......-arc Petri nets, we explore new data structures for lowering the used memory: PTries for efficient storing of configurations and time darts for semi-symbolic description of the state-space. Both methods are implemented as a part of the tool TAPAAL and the experiments document at least one order of magnitude...... of memory savings while preserving comparable verification times....
Mathews, A; Mogg, K; May, J; Eysenck, M
Previous investigations of recall and recognition for threatening information in clinically anxious subjects have yielded equivocal results. The present study contrasts implicit (word completion) with explicit (cued recall) memory and shows that indices of bias for emotional material derived from the two types of memory are independent of one another. The explicit measure was correlated with trait anxiety scores, but did not clearly distinguish between subjects with clinical anxiety states and normal control subjects. On the implicit memory measure, clinically anxious subjects produced more threat word completions, but only from a set to which they had recently been exposed. These results are taken as evidence that internal representations of threat words are more readily or more persistently activated in anxiety states, although they are not necessarily better elaborated.
Full Text Available Objective: Stuttering is one of the most common speech disorders. However, its etiology is poorly understood, and is likely to be heterogeneous. Impairment of cognitive functions such as emotional memory and attention is one of the important factors. The aim of this research is to compare explicit and implicit memory between stutterers and normal individuals and also comparison of anxiety and depression between 2 groups. Materials & Methods: This is a case-control and analytical research.The participated individuals in this research were 30 male and female stutterers and the same number as the matched control group. The control group was matched for gender, age, education and bilingualism. The cue recall task performed to investigate explicit memory and the word stem completing task for implicit memory. The anxiety and depression of the individuals were measured by using general Hygiene Questionnaire (GHQ28 in this study. The performance of the individuals was measured based on positive and negative words in explicit and implicit memory and was compared with anxiety and depression score they obtained. Data was analyzed by using independent T-test, paired T-test, U-Man Witney and Willkaxon test. Results: The data indicated that stutterers recognized less emotionally positive words in explicit memory as compared with nonstutterers. Also, stutterers recognized more emotionally negative words as compared with emotionally positive words in explicit and implicit memory tasks (P<0/05. Additionally, stutterers showed more anxiety and depression as compared to nonstutterers. This difference was significant except for depression (P0.05. Conclusion: Taking into consideration the role of cognitive functions including emotional memory in motor speech programming and the difference in the function of positive versus negative emotional memories between stutterers and nonstutterers in this research, the role of emotional memory can be considered as an important
MacLeod, C; McLaughlin, K
Williams, Watts, MacLeod and Mathews' (1988) [Cognitive psychology and the emotional disorders. Chichester, Wiley] model of anxiety and cognition leads to the prediction that anxious subjects will show an implicit, but not an explicit, memory advantage for threat-related information. Mathews, Mogg, May and Eysenck (1989) [Journal of Abnormal Psychology, 98, 401-407] obtained marginally significant support for this prediction in an experiment that tested memory using word stem completion tasks following a self-referent encoding procedure. However, neither the reliability nor generality of these findings have been established. The current experiment was designed to provide a conceptual replication of Mathews et al.'s study, using different tests of implicit memory (i.e. tachistoscopic identification) and explicit memory (i.e. recognition) and an alternative type of encoding task (i.e. colour naming stimulus words). 16 generalised anxiety disorder patients, and 16 non-anxious control subjects were tested. As predicted, the anxiety patients showed a relative implicit memory advantage for threat-related stimulus words, while the two subject groups did not differ in their pattern of explicit memory performance. These results support the predictions generated by Williams et al.'s model of anxiety and cognition.
Luethi, Mathias; Meier, Beat; Sandi, Carmen
Stress is a strong modulator of memory function. However, memory is not a unitary process and stress seems to exert different effects depending on the memory type under study. Here, we explored the impact of social stress on different aspects of human memory, including tests for explicit memory and working memory (for neutral materials), as well as implicit memory (perceptual priming, contextual priming and classical conditioning for emotional stimuli). A total of 35 young adult male students were randomly assigned to either the stress or the control group, with stress being induced by the Trier Social Stress Test (TSST). Salivary cortisol levels were assessed repeatedly throughout the experiment to validate stress effects. The results support previous evidence indicating complex effects of stress on different types of memory: A pronounced working memory deficit was associated with exposure to stress. No performance differences between groups of stressed and unstressed subjects were observed in verbal explicit memory (but note that learning and recall took place within 1 h and immediately following stress) or in implicit memory for neutral stimuli. Stress enhanced classical conditioning for negative but not positive stimuli. In addition, stress improved spatial explicit memory. These results reinforce the view that acute stress can be highly disruptive for working memory processing. They provide new evidence for the facilitating effects of stress on implicit memory for negative emotional materials. Our findings are discussed with respect to their potential relevance for psychiatric disorders, such as post traumatic stress disorder.
Full Text Available Stress is a strong modulator of memory function. However, memory is not a unitary process and stress seems to exert different effects depending on the memory type under study. Here, we explored the impact of social stress on different aspects of human memory, including tests for explicit memory and working memory (for neutral materials, as well as implicit memory (perceptual priming, contextual priming and classical conditioning for emotional stimuli. A total of 35 young adult male students were randomly assigned to either the stress or the control group, with stress being induced by the Trier Social Stress Test (TSST. Salivary cortisol levels were assessed repeatedly throughout the experiment to validate stress effects. The results support previous evidence indicating complex effects of stress on different types of memory: A pronounced working memory deficit was associated with exposure to stress. No performance differences between groups of stressed and unstressed subjects were observed in verbal explicit memory (but note that learning and recall took place within 1 hour and immediately following stress or in implicit memory for neutral stimuli. Stress enhanced classical conditioning for negative but not positive stimuli. In addition, stress improved spatial explicit memory. These results reinforce the view that acute stress can be highly disruptive for working memory processing. They provide new evidence for the facilitating effects of stress on implicit memory for negative emotional materials. Our findings are discussed with respect to their potential relevance for psychiatric disorders, such as post traumatic stress disorder.
Rose, Michael; Haider, Hilde; Büchel, Christian
In incidental learning situations, contingencies are extracted from the environment without the intention to learn and can change behavior without awareness for the extracted regularity. The development of explicit access to the learned regularity is an important learning mechanism that is rarely examined. With a series of behavioral, electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) studies, we were able to show that the emergence of awareness for a hidden regularity is accompanied by an increase in neural activity and in high-frequency coupling between distant brain areas as observed with a time-frequency resolved EEG analysis. More importantly, the increase in neural coupling was observed before awareness for the learned material was established behaviorally. In addition, coupling increases were paralleled by an fMRI-signal increase in the ventral striatum and the right ventrolateral prefrontal cortex directly preceding the emergence of awareness. The involvement of this system, which has already been linked to the processing of predictions and prediction errors, indicates the relevance of a reinforcement signal to generate awareness for the learned contingencies. Thus, our data provide direct evidence for the necessity of large-scale coupling and the evaluation of a predictive stimulus value as the basis for a transition from implicit to explicit memory.
Burton, Leslie A; Rabin, Laura; Vardy, Susan Bernstein; Frohlich, Jonathan; Wyatt, Gwinne; Dimitri, Diana; Constante, Shimon; Guterman, Elan
Thirty-two participants were administered 4 verbal tasks, an Implicit Affective Task, an Implicit Neutral Task, an Explicit Affective Task, and an Explicit Neutral Task. For the Implicit Tasks, participants were timed while reading passages aloud as quickly as possible, but not so quickly that they did not understand. A target verbal passage was repeated three times, and alternated with other previously unread passages. The Implicit Affective and Neutral passages had strong affective or neutral content, respectively. The Explicit Tasks were administered at the end of testing, and consisted of multiple choice questions regarding the passages. Priming effects in terms of more rapid reading speed for the target compared to non-target passages were seen for both the Implicit Affective Task and the Implicit Neutral Task. Overall reading speed was faster for the passages with neutral compared to affective content, consistent with studies of the emotional Stroop effect. For the Explicit memory tasks, overall performance was better on the items from the repeated passage, and on the Affective compared to Neutral Task. The male subjects showed greater priming for affective material than female subjects, and a greater gain than female subjects in explicit memory for affective compared to neutral material.
Zannino, Gian Daniele; Perri, Roberta; Zabberoni, Silvia; Caltagirone, Carlo; Marra, Camillo; Carlesimo, Giovanni A
Evidence shows that amnesic patients are able to categorize new exemplars drawn from the same prototype as in previously encountered items. It is still unclear, however, whether this ability is due to a spared implicit learning system or residual explicit memory and/or working memory resources. In this study, we used a new paradigm devised expressly to rule out any possible contribution of episodic and working memory in performing a prototype distortion task. We enrolled patients with amnesic MCI and Normal Controls. Our paradigm consisted of a study phase and a test phase; two-thirds of the participants performed the study phase and all participants performed the test phase. In the study phase, participants had to judge how pleasant morphed faces, drawn from a single prototype, seemed to them. Half of the participants were shown faces drawn from the A-prototype and half from the B-prototype. A- and B-faces were opposite in a morphing space with a neutral human face at the center. In the test phase, participants had to judge the regularity of faces they had never seen before. Three different types of faces were shown in the test phase, that is, A-, B-, or neutral-faces. We expected that implicit learning of the category boundaries would lead to a category-specific increase in perceived regularity. The results confirmed our predictions. In fact, trained subjects (compared with subjects who did not undergo the study phase) assigned higher regularity scores to new faces drawn from the same prototype as the faces seen during training, and they gave lower regularity scores to new faces drawn from the opposite prototype. This effect was super imposable across subjects' groups. Copyright © 2012 Elsevier Ltd. All rights reserved.
Lorenzi, I; Giunta, F; Di Stefano, M
The study was aimed to investigate whether impending surgery, considered as a stressful life event, might interfere with memory formation like other stress and anxiety conditions do. Results do not support the hypothesis. Implicit and explicit memory performance are both unaffected by presurgery condition and seem influenced, rather, by subjects gender, education and cultural habits. Females perform generally better than males and, regardless of age and sex, higher educated individuals score higher on the explicit memory task. The habits of reading books and doing crosswords are associated to best performance on explicit and implicit memory task respectively.
Ballesteros, Soledad; Reales, José M; García, Eulalio; Carrasco, Marisa
Three experiments investigated the effects of two variables -selective attention during encoding and delay between study and test- on implicit (picture fragment completion and object naming) and explicit (free recall and recognition) memory tests. Experiments 1 and 2 consistently indicated that (a) at all delays (immediate to 1 month), picture-fragment identification threshold was lower for the attended than the unattended pictures; (b) the attended pictures were recalled and recognized better than the unattended; and (c) attention and delay interacted in both memory tests. For implicit memory, performance decreased as delay increased for both attended and unattended pictures, but priming was more pronounced and lasted longer for the attended pictures; it was still present after a 1-month delay. For explicit memory, performance decreased as delay increased for attended pictures, but for unattended pictures performance was consistent throughout delay. By using a perceptual object naming task, Experiment 3 showed reliable implicit and explicit memory for attended but not for unattended pictures. This study indicates that picture repetition priming requires attention at the time of study and that neither delay nor attention dissociate performance in explicit and implicit memory tests; both types of memory require attention, but explicit memory does so to a larger degree.
Full Text Available We present detailed experimental work involving a commercially available large scale shared memory multiple instruction stream-multiple data stream (MIMD parallel computer having a software controlled cache coherence mechanism. To make effective use of such an architecture, the programmer is responsible for designing the program's structure to match the underlying multiprocessors capabilities. We describe the techniques used to exploit our multiprocessor (the BBN TC2000 on a network simulation program, showing the resulting performance gains and the associated programming costs. We show that an efficient implementation relies heavily on the user's ability to explicitly manage the memory system.
Full Text Available Memory conformity occurs when an individual endorses what other individuals remember about past events. Research on memory conformity is currently dominated by a 'forensic' perspective, which views the phenomenon as inherently undesirable. This is because conformity not only distorts the accuracy of an individual's memory, but also produces false corroboration between individuals, effects that act to undermine criminal justice systems. There is growing awareness, however, that memory conformity may be interpreted more generally as an adaptive social behavior regulated by explicit mentalizing mechanisms. Here, we provide novel evidence in support of this emerging alternative theoretical perspective. We carried out a memory conformity experiment which revealed that explicit belief-simulation (i.e. using one's own beliefs to model what other people believe systematically biases conformity towards like-minded individuals, even when there is no objective evidence that they have a more accurate memory than dissimilar individuals. We suggest that this bias is functional, i.e. adaptive, to the extent that it fosters trust, and hence cooperation, between in-group versus out-group individuals. We conclude that memory conformity is, in more fundamental terms, a highly desirable product of explicit mentalizing mechanisms that promote adaptive forms of social learning and cooperation.
Wheeler, Rebecca; Allan, Kevin; Tsivilis, Dimitris; Martin, Douglas; Gabbert, Fiona
Memory conformity occurs when an individual endorses what other individuals remember about past events. Research on memory conformity is currently dominated by a 'forensic' perspective, which views the phenomenon as inherently undesirable. This is because conformity not only distorts the accuracy of an individual's memory, but also produces false corroboration between individuals, effects that act to undermine criminal justice systems. There is growing awareness, however, that memory conformity may be interpreted more generally as an adaptive social behavior regulated by explicit mentalizing mechanisms. Here, we provide novel evidence in support of this emerging alternative theoretical perspective. We carried out a memory conformity experiment which revealed that explicit belief-simulation (i.e. using one's own beliefs to model what other people believe) systematically biases conformity towards like-minded individuals, even when there is no objective evidence that they have a more accurate memory than dissimilar individuals. We suggest that this bias is functional, i.e. adaptive, to the extent that it fosters trust, and hence cooperation, between in-group versus out-group individuals. We conclude that memory conformity is, in more fundamental terms, a highly desirable product of explicit mentalizing mechanisms that promote adaptive forms of social learning and cooperation.
Mori, M; Graf, P
Memory research distinguishes two components of episodes--the event or item and the spatial-temporal setting or context in which it occurred. The word context is used either globally to denote the physical, social, or emotional environment at study and test or it is used locally to refer to another word or picture that was paired with a particular target. In this article, we report four experiments that investigated the influence of two different nonverbal local contexts on explicit word recognition and implicit word identification test performance. In each experiment, university students studied words that were displayed against various extra-item local contexts, and the contexts were either the same or different at study and test. What differed across experiments was the nature of the contexts: for Experiments 1 and 2, it was a band of color that stretched across the computer screen, and for Experiments 3 and 4, the context was a colored line drawing. The combined findings from all experiments provide no evidence of memory context effects (MCE) on priming. By contrast, recognition test performance showed reliable MCEs but only when the local context was a concrete drawing or when it was a color that was target-related or appropriate. The discussion compared these findings with those from previous studies that concerned the cueing effectiveness of verbal and nonverbal extra-item contexts.
Lüthi, Mathias; Meier, Beat; Sandi, Carmen
Stress is a strong modulator of memory function. However, memory is not a unitary process and stress seems to exert different effects depending on the memory type under study. Here, we explored the impact of social stress on different aspects of human memory, including tests for explicit memory and working memory (for neutral materials), as well as implicit memory (perceptual priming, contextual priming and classical conditioning for emotional stimuli). A total of 35 young adult...
Humans can acquire new information and modify it (cumulative culture) based on their learning and memory abilities, especially explicit memory, through the processes of encoding, consolidation, storage, and retrieval. Explicit memory is categorized into semantic and episodic memories. Animals have semantic memory, while episodic memory is unique to humans and essential for innovation and the evolution of culture. As both episodic and semantic memory are needed for innovation, the evolution of explicit memory influences the evolution of culture. However, previous theoretical studies have shown that environmental fluctuations influence the evolution of imitation (social learning) and innovation (individual learning) and assume that memory is not an evolutionary trait. If individuals can store and retrieve acquired information properly, they can modify it and innovate new information. Therefore, being able to store and retrieve information is essential from the perspective of cultural evolution. However, if both storage and retrieval were too costly, forgetting and relearning would have an advantage over storing and retrieving acquired information. In this study, using mathematical analysis and individual-based simulations, we investigate whether cumulative culture can promote the coevolution of costly memory and social and individual learning, assuming that cumulative culture improves the fitness of each individual. The conclusions are: (1) without cumulative culture, a social learning cost is essential for the evolution of storage-retrieval. Costly storage-retrieval can evolve with individual learning but costly social learning does not evolve. When low-cost social learning evolves, the repetition of forgetting and learning is favored more than the evolution of costly storage-retrieval, even though a cultural trait improves the fitness. (2) When cumulative culture exists and improves fitness, storage-retrieval can evolve with social and/or individual learning, which
Weber, Frederik D; Wang, Jing-Yi; Born, Jan; Inostroza, Marion
Research in rats using preferences during exploration as a measure of memory has indicated that sleep is important for the consolidation of episodic-like memory, i.e., memory for an event bound into specific spatio-temporal context. How these findings relate to human episodic memory is unclear. We used spontaneous preferences during visual exploration and verbal recall as, respectively, implicit and explicit measures of memory, to study effects of sleep on episodic memory consolidation in humans. During encoding before 10-h retention intervals that covered nighttime sleep or daytime wakefulness, two groups of young adults were presented with two episodes that were 1-h apart. Each episode entailed a spatial configuration of four different faces in a 3 × 3 grid of locations. After the retention interval, implicit spatio-temporal recall performance was assessed by eye-tracking visual exploration of another configuration of four faces of which two were from the first and second episode, respectively; of the two faces one was presented at the same location as during encoding and the other at another location. Afterward explicit verbal recall was assessed. Measures of implicit and explicit episodic memory retention were positively correlated (r = 0.57, P sleep than daytime wakefulness (P sleep group, implicit episodic memory recall was associated with increased fast spindles during nonrapid eye movement (NonREM) sleep (r = 0.62, P benefits from sleep.
Nguyen-Louie, Tam T.; Buckman, Jennifer F.; Ray, Suchismita
Background Alcohol cues can bias attention and elicit emotional reactions, especially in drinkers. Yet, little is known about how alcohol cues affect explicit and implicit memory processes, and how memory for alcohol cues is affected by acute alcohol intoxication. Methods Young adult participants (N=161) were randomly assigned to alcohol, placebo, or control beverage conditions. Following beverage consumption, they were shown neutral, emotional and alcohol-related pictures cues. Participants then completed free recall and repetition priming tasks to test explicit and implicit memory, respectively, for picture cues. Average blood alcohol concentration for the alcohol group was 74 ± 13 mg/dl when memory testing began. Two mixed linear model analyses were conducted to examine the effects of beverage condition, picture cue type, and their interaction on explicit and implicit memory. Results Picture cue type and beverage condition each significantly affected explicit recall of picture cues, whereas only picture cue type significantly influenced repetition priming. Individuals in the alcohol condition recalled significantly fewer pictures than those in other conditions, regardless of cue type. Both free recall and repetition priming were greater for emotional and alcohol-related cues compared to neutral picture cues. No interaction effects were detected. Conclusions Young adult drinkers showed enhanced explicit and implicit memory processing of alcohol cues compared to emotionally neutral cues. This enhanced processing for alcohol cues was on par with that seen for positive emotional cues. Acute alcohol intoxication did not alter this preferential memory processing for alcohol cues over neutral cues. PMID:26811126
Nguyen-Louie, Tam T; Buckman, Jennifer F; Ray, Suchismita; Bates, Marsha E
Alcohol cues can bias attention and elicit emotional reactions, especially in drinkers. Yet, little is known about how alcohol cues affect explicit and implicit memory processes, and how memory for alcohol cues is affected by acute alcohol intoxication. Young adult participants (N=161) were randomly assigned to alcohol, placebo, or control beverage conditions. Following beverage consumption, they were shown neutral, emotional and alcohol-related pictures cues. Participants then completed free recall and repetition priming tasks to test explicit and implicit memory, respectively, for picture cues. Average blood alcohol concentration for the alcohol group was 74±13mg/dl when memory testing began. Two mixed linear model analyses were conducted to examine the effects of beverage condition, picture cue type, and their interaction on explicit and implicit memory. Picture cue type and beverage condition each significantly affected explicit recall of picture cues, whereas only picture cue type significantly influenced repetition priming. Individuals in the alcohol condition recalled significantly fewer pictures than those in other conditions, regardless of cue type. Both free recall and repetition priming were greater for emotional and alcohol-related cues compared to neutral picture cues. No interaction effects were detected. Young adult drinkers showed enhanced explicit and implicit memory processing of alcohol cues compared to emotionally neutral cues. This enhanced processing for alcohol cues was on par with that seen for positive emotional cues. Acute alcohol intoxication did not alter this preferential memory processing for alcohol cues over neutral cues. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Geyer, Thomas; Mueller, Hermann J; Assumpcao, Leonardo; Gais, Steffen
In repeated visual search tasks, facilitation of reaction times (RTs) due to repetition of the spatial arrangement of items occurs independently of RT facilitation due to improvements in general task performance. Whereas the latter represents typical procedural learning, the former is a kind of implicit memory that depends on the medial temporal lobe (MTL) memory system and is impaired in patients with amnesia. A third type of memory that develops during visual search is the observers' explicit knowledge of repeated displays. Here, we used a visual search task to investigate whether procedural memory, implicit contextual cueing, and explicit knowledge of repeated configurations, which all arise independently from the same set of stimuli, are influenced by sleep. Observers participated in two experimental sessions, separated by either a nap or a controlled rest period. In each of the two sessions, they performed a visual search task in combination with an explicit recognition task. We found that (1) across sessions, MTL-independent procedural learning was more pronounced for the nap than rest group. This confirms earlier findings, albeit from different motor and perceptual tasks, showing that procedural memory can benefit from sleep. (2) Likewise, the sleep group compared with the rest group showed enhanced context-dependent configural learning in the second session. This is a novel finding, indicating that the MTL-dependent, implicit memory underlying contextual cueing is also sleep-dependent. (3) By contrast, sleep and wake groups displayed equivalent improvements in explicit recognition memory in the second session. Overall, the current study shows that sleep affects MTL-dependent as well as MTL-independent memory, but it affects different, albeit simultaneously acquired, forms of MTL-dependent memory differentially.
Casey, Sarah J; Solomons, Luke C; Steier, Joerg; Kabra, Neeraj; Burnside, Anna; Pengo, Martino F; Moxham, John; Goldstein, Laura H; Kopelman, Michael D
It has been debated whether different stages in the human sleep cycle preferentially mediate the consolidation of explicit and implicit memories, or whether all of the stages in succession are necessary for optimal consolidation. Here we investigated whether the selective deprivation of slow wave sleep (SWS) or rapid eye movement (REM) sleep over an entire night would have a specific effect on consolidation in explicit and implicit memory tasks. Participants completed a set of explicit and implicit memory tasks at night, prior to sleep. They had 1 control night of undisturbed sleep and 2 experimental nights, during which either SWS or REM sleep was selectively deprived across the entire night (sleep conditions counterbalanced across participants). Polysomnography recordings quantified precisely the amount of SWS and REM sleep that occurred during each of the sleep conditions, and spindle counts were recorded. In the morning, participants completed the experimental tasks in the same sequence as the night before. SWS deprivation disrupted the consolidation of explicit memories for visuospatial information (ηp2 = .23), and both SWS (ηp2 = .53) and REM sleep (ηp2 = .52) deprivation adversely affected explicit verbal recall. Neither SWS nor REM sleep deprivation affected aspects of short-term or working memory, and did not affect measures of verbal implicit memory. Spindle counts did not correlate significantly with memory performance. These findings demonstrate the importance of measuring the sleep cycles throughout the entire night, and the contribution of both SWS and REM sleep to memory consolidation. (PsycINFO Database Record (c) 2016 APA, all rights reserved).
Johns, Adam; Homewood, Judi; Stevenson, Richard; Taylor, Alan
This study examined differences in implicit and explicit memory performance between people with Down syndrome (DS), their siblings, children matched on mental age, and university undergraduates, using olfactory stimuli. The DS and mental-age matched participants were also compared on two tasks of executive function. The data revealed implicit…
Cousins, James N; El-Deredy, Wael; Parkes, Laura M; Hennies, Nora; Lewis, Penelope A
Memories are gradually consolidated after initial encoding, and this can sometimes lead to a transition from implicit to explicit knowledge. The exact physiological processes underlying this reorganization remain unclear. Here, we used a serial reaction time task to determine whether targeted memory reactivation (TMR) of specific memory traces during slow-wave sleep promotes the emergence of explicit knowledge. Human participants learned two 12-item sequences of button presses (A and B). These differed in both cue order and in the auditory tones associated with each of the four fingers (one sequence had four higher-pitched tones). Subsequent overnight sleep was monitored, and the tones associated with one learned sequence were replayed during slow-wave sleep. After waking, participants demonstrated greater explicit knowledge (p = 0.005) and more improved procedural skill (p = 0.04) for the cued sequence relative to the uncued sequence. Furthermore, fast spindles (13.5-15 Hz) at task-related motor regions predicted overnight enhancement in procedural skill (r = 0.71, p = 0.01). Auditory cues had no effect on post-sleep memory performance in a control group who received TMR before sleep. These findings suggest that TMR during sleep can alter memory representations and promote the emergence of explicit knowledge, supporting the notion that reactivation during sleep is a key mechanism in this process. Copyright © 2014 Cousins et al.
Fama, Rosemary; Rosenbloom, Margaret J; Sassoon, Stephanie A; Rohlfing, Torsten; Pfefferbaum, Adolf; Sullivan, Edith V
Component cognitive and motor processes contributing to diminished visuomotor procedural learning in HIV infection with comorbid chronic alcoholism (HIV+ALC) include problems with attention and explicit memory processes. The neural correlates associated with this constellation of cognitive and motor processes in HIV infection and alcoholism have yet to be delineated. Frontostriatal regions are affected in HIV infection, frontothalamocerebellar regions are affected in chronic alcoholism, and frontolimbic regions are likely affected in both; all three of these systems have the potential of contributing to both visuomotor procedural learning and explicit memory processes. Here, we examined the neural correlates of implicit memory, explicit memory, attention, and motor tests in 26 HIV+ALC (5 with comorbidity for nonalcohol drug abuse/dependence) and 19 age-range matched healthy control men. Parcellated brain volumes, including cortical, subcortical, and allocortical regions, as well as cortical sulci and ventricles, were derived using the SRI24 brain atlas. Results indicated that smaller thalamic volumes were associated with poorer performance on tests of explicit (immediate and delayed) and implicit (visuomotor procedural) memory in HIV+ALC. By contrast, smaller hippocampal volumes were associated with lower scores on explicit, but not implicit memory. Multiple regression analyses revealed that volumes of both the thalamus and the hippocampus were each unique independent predictors of explicit memory scores. This study provides evidence of a dissociation between implicit and explicit memory tasks in HIV+ALC, with selective relationships observed between hippocampal volume and explicit but not implicit memory, and highlights the relevance of the thalamus to mnemonic processes.
Garfinkel, S.N; Dienes, Zoltán; Duka, Theodora
Rationale Alcohol impairs explicit memory, whilst leaving implicit memory relatively intact. Less is known about its effects on false memories. Aim The present study examines the effects of alcohol on explicit and implicit false memories using study list repetition as a tool for modulating learning at encoding. Methods Thirty-two participants were given either an alcohol (0.6 g/kg) or placebo beverage before undergoing an encoding phase consisting of 10 lists of nine associated words (veridic...
Moon, Chung-Man; Yang, Jong-Chul; Jeong, Gwang-Woo
The functional neuroanatomy for explicit memory in conjunction with the major anxiety symptoms in patients with generalized anxiety disorder (GAD) has not yet been clearly identified. To investigate the brain activation patterns on the interaction between emotional and cognitive function during the explicit memory tasks, as well as its correlation with clinical characteristics in GAD. The participants comprised GAD patients and age-matched healthy controls. The fMR images were obtained while the participants performed an explicit memory task with neutral and anxiety-inducing words. Patients showed significantly decreased functional activities in the putamen, head of the caudate nucleus, hippocampus, and middle cingulate gyrus during the memory tasks with the neutral and anxiety-inducing words, whereas the precentral gyrus and ventrolateral prefrontal cortex were significantly increased only in the memory tasks with the anxiety-inducing words. Also, the blood oxygenation level-dependent (BOLD) signal changes in the hippocampus were positively correlated with the recognition accuracy for both neutral and anxiety-inducing words. This study identified the brain areas associated with the interaction between emotional regulation and cognitive function in the explicit memory tasks in patients with GAD. These findings would be helpful to understand the neural mechanism on the explicit memory-related cognitive deficits and emotional dysfunction with GAD symptoms. © The Foundation Acta Radiologica 2016.
Full Text Available Studies have shown a time-of-day of training effect on long-term explicit memory with a greater effect being shown in the afternoon than in the morning. However, these studies did not control the chronotype variable. Therefore, the purpose of this study was to assess if the time-of-day effect on explicit memory would continue if this variable were controlled, in addition to identifying the occurrence of a possible synchronic effect. A total of 68 undergraduates were classified as morning, intermediate, or afternoon types. The subjects listened to a list of 10 words during the training phase and immediately performed a recognition task, a procedure which they repeated twice. One week later, they underwent an unannounced recognition test. The target list and the distractor words were the same in all series. The subjects were allocated to two groups according to acquisition time: a morning group (N = 32, and an afternoon group (N = 36. One week later, some of the subjects in each of these groups were subjected to a test in the morning (N = 35 or in the afternoon (N = 33. The groups had similar chronotypes. Long-term explicit memory performance was not affected by test time-of-day or by chronotype. However, there was a training time-of-day effect [F (1,56 = 53.667; P = 0.009] with better performance for those who trained in the afternoon. Our data indicated that the advantage of training in the afternoon for long-term memory performance does not depend on chronotype and also that this performance is not affected by the synchronic effect.
Preston, Alison R.; Gabrieli, John D. E.
Using functional magnetic resonance imaging, the current study explored the differential mnemonic contributions of the hippocampus and surrounding medial temporal lobe (MTL) cortices to explicit recognition memory and configural learning. Using a task that required processing of repeated and novel visuospatial contexts across multiple trials, we examined MTL activation in relation to 3 forms of learning in a single paradigm: 1) context-independent procedural learning, 2) context-dependent con...
Full Text Available Objective: The aim of current research was to assess implicit and explicit memory bias to drug related stimuli in opiate Dependent, abstinent and normal Individuals. Method: Three groups including opiate Dependent, abstinent and normal Individuals (n=25 were selected by available sampling method. After matching on the base of age, education level and type of substance use all participants assessed by recognition task (explicit memory bias and stem completion task (implicit memory bias. Results: The analysis of data showed that opiate dependent and abstinent groups in comparison with normal individual had implicit memory bias, whereas in explicit memory only opiate dependent individuals showed bias. Conclusion: The identification of explicit and implicit memory governing addiction may have practical implications in diagnosis, treatment and prevention of substance abuse.
Kang, Heoung Keun; Jeong, Gwang Woo; Park, Tae Jin; Seo, Jeong Jin; Kim, Hyung Joong; Eun, Sung Jong; Chung, Tae Woong [Chonnam National University Medical School, Gwangju (Korea, Republic of)
hemisphere during both implicit and explicit retrieval tasks. For explicit retrieval, the lateralization index was more than twice as high as for implicit retrieval. Our findings indicate that three is neuro-anatomical dissociation between implicit and explicit retrieval of words during conceptual processing, suggesting, on the basis of cognitive neuroscience, that the performance of implicit and explicit memory-related tasks involves different mechanisms.
Garfinkel, S N; Dienes, Z; Duka, T
Alcohol impairs explicit memory, whilst leaving implicit memory relatively intact. Less is known about its effects on false memories. The present study examines the effects of alcohol on explicit and implicit false memories using study list repetition as a tool for modulating learning at encoding. Thirty-two participants were given either an alcohol (0.6 g/kg) or placebo beverage before undergoing an encoding phase consisting of 10 lists of nine associated words (veridical items). Each list was associated to a word, which was not presented at encoding (semantically associated non-studied lure; critical item), serving as the measure for false memory. Half of the lists were presented once, and half were repeated three times. The next day, participants underwent an implicit (stem completion and post hoc awareness measurements), and an explicit (free recall) task. Alcohol decreased veridical and false explicit memory for singularly presented lists compared to placebo; no group difference existed for repeated lists. Implicit veridical memory was not affected by alcohol. Awareness memory measures demonstrated in placebo participants an increased ability with repetition in rejecting false memories. The reverse was found in intoxicated participants who with repetition accepted more false memories. Alcohol appears to decrease semantic activation leading to a decline in false memories. Increased learning with repetition, which increases the rejection of false memories under placebo, is reversed under alcohol leading to a decrease in rejection of false memories. The latter effect of alcohol may be due to its ability to impair monitoring processes established at encoding.
Eich, Teal S; Metcalfe, Janet
We tested the idea that real-world situations, such as the highly strenuous exercise involved in marathon running, that impose extreme physical demands on an individual may result in neurohormonal changes that alter the functioning of memory. Marathon runners were given implicit and explicit memory tasks before or immediately after they completed a marathon. Runners tested immediately upon completing the marathon showed impairment in the explicit memory task but enhancement in the implicit memory task. This postmarathon impairment in explicit memory is similar to that seen with amnesic patients with organic brain damage. However, no previous studies have shown a simultaneous enhancement in the implicit memory task, as shown by the marathon runners in the present study. This study indicates that human memory functioning can be dynamically altered by such activities as marathon running, in which hundreds of thousands of healthy normal individuals routinely partake.
McBride, Dawn M; Thomas, Brandon J; Zimmerman, Corinne
The present study was designed to investigate the survival processing effect (Nairne, Thompson, & Pandeirada, Journal of Experimental Psychology: Learning, Memory, and Cognition, 33, 263-273, 2007) in cued implicit and explicit memory tests. The survival effect has been well established in explicit free recall and recognition tests, but has not been evident in implicit memory tests or in cued explicit tests. In Experiment 1 of the present study, we tested implicit and explicit memory for words studied in survival, moving, or pleasantness contexts in stem completion tests. In Experiment 2, we further tested these effects in implicit and explicit category production tests. Across the two experiments, with four separate memory tasks that included a total of 525 subjects, no survival processing advantage was found, replicating the results from implicit tests reported by Tse and Altarriba (Memory & Cognition, 38, 1110-1121, 2010). Thus, although the survival effect appears to be quite robust in free recall and recognition tests, it has not been replicated in cued implicit and explicit memory tests. The similar results found for the implicit and explicit tests in the present study do not support encoding elaboration explanations of the survival processing effect.
Ward, Emily J; Chun, Marvin M; Kuhl, Brice A
Repeated exposure to a visual stimulus is associated with corresponding reductions in neural activity, particularly within visual cortical areas. It has been argued that this phenomenon of repetition suppression is related to increases in processing fluency or implicit memory. However, repetition of a visual stimulus can also be considered in terms of the similarity of the pattern of neural activity elicited at each exposure--a measure that has recently been linked to explicit memory. Despite the popularity of each of these measures, direct comparisons between the two have been limited, and the extent to which they differentially (or similarly) relate to behavioral measures of memory has not been clearly established. In the present study, we compared repetition suppression and pattern similarity as predictors of both implicit and explicit memory. Using functional magnetic resonance imaging, we scanned 20 participants while they viewed and categorized repeated presentations of scenes. Repetition priming (facilitated categorization across repetitions) was used as a measure of implicit memory, and subsequent scene recognition was used as a measure of explicit memory. We found that repetition priming was predicted by repetition suppression in prefrontal, parietal, and occipitotemporal regions; however, repetition priming was not predicted by pattern similarity. In contrast, subsequent explicit memory was predicted by pattern similarity (across repetitions) in some of the same occipitotemporal regions that exhibited a relationship between priming and repetition suppression; however, explicit memory was not related to repetition suppression. This striking double dissociation indicates that repetition suppression and pattern similarity differentially track implicit and explicit learning.
Moon, Chung-Man; Jeong, Gwang-Woo
Background The neuroanatomical abnormalities associated with behavioral dysfunction on explicit memory in patients generalized anxiety disorder (GAD) have not yet been clearly identified. Purpose To investigate the regional gray matter (GM) and white matter (WM) volume alterations over the whole brain in patients with GAD, as well as the correlation between the brain structural abnormality and explicit memory dysfunction. Material and Methods Twenty patients with GAD and 20 healthy controls matched for age, sex, and education level underwent high-resolution T1-weighted magnetic resonance imaging (MRI). The participants performed the explicit memory tasks with the neutral and anxiety-inducing words. Results Patients with GAD showed significantly reduced GM volumes in the midbrain (MB), thalamus, hippocampus (Hip), insula, and superior temporal gyrus (STG); and reduced WM volumes in the MB, anterior limb of the internal capsule (ALIC), dorsolateral prefrontal cortex (DLPFC), and precentral gyrus (PrG). It is important to note that the GM volume of the Hip and the WM volume of the DLPFC were positively correlated with the recognition accuracy (%) in the explicit memory tasks with neutral and anxiety-inducing words, respectively. On the other hand, the WM volume of the PrG was negatively correlated with the reaction time in the same memory tasks. Conclusion This study demonstrated the regional volume changes on whole-brain GM and WM and the correlation between the brain structural alteration and explicit memory dysfunction in GAD patients. These findings would be helpful to understand the association between the brain structure abnormality and the functional deficit in the explicit memory in GAD.
Narme, Pauline; Peretz, Isabelle; Strub, Marie-Laure; Ergis, Anne-Marie
Normal aging affects explicit memory while leaving implicit memory relatively spared. Normal aging also modifies how emotions are processed and experienced, with increasing evidence that older adults (OAs) focus more on positive information than younger adults (YAs). The aim of the present study was to investigate how age-related changes in emotion processing influence explicit and implicit memory. We used emotional melodies that differed in terms of valence (positive or negative) and arousal (high or low). Implicit memory was assessed with a preference task exploiting exposure effects, and explicit memory with a recognition task. Results indicated that effects of valence and arousal interacted to modulate both implicit and explicit memory in YAs. In OAs, recognition was poorer than in YAs; however, recognition of positive and high-arousal (happy) studied melodies was comparable. Insofar as socioemotional selectivity theory (SST) predicts a preservation of the recognition of positive information, our findings are not fully consistent with the extension of this theory to positive melodies since recognition of low-arousal (peaceful) studied melodies was poorer in OAs. In the preference task, YAs showed stronger exposure effects than OAs, suggesting an age-related decline of implicit memory. This impairment is smaller than the one observed for explicit memory (recognition), extending to the musical domain the dissociation between explicit memory decline and implicit memory relative preservation in aging. Finally, the disproportionate preference for positive material seen in OAs did not translate into stronger exposure effects for positive material suggesting no age-related emotional bias in implicit memory. (PsycINFO Database Record (c) 2016 APA, all rights reserved).
Shanks, David R; Berry, Christopher J
This article reviews recent work aimed at developing a new framework, based on signal detection theory, for understanding the relationship between explicit (e.g., recognition) and implicit (e.g., priming) memory. Within this framework, different assumptions about sources of memorial evidence can be framed. Application to experimental results provides robust evidence for a single-system model in preference to multiple-systems models. This evidence comes from several sources including studies of the effects of amnesia and ageing on explicit and implicit memory. The framework allows a range of concepts in current memory research, such as familiarity, recollection, fluency, and source memory, to be linked to implicit memory. More generally, this work emphasizes the value of modern computational modelling techniques in the study of learning and memory.
Casey, Sarah; Solomons, Luke C.; Steier, Joerg Sebastian; Kabra, Neeraj; Burnside, Anna; Pengo, Martino F; Moxham, John; Goldstein, Laura Hilary; Kopelman, M D
Objective: It has been debated whether different stages in the human sleep cycle preferentially mediate the consolidation of explicit and implicit memories, or whether all of the stages in succession are necessary for optimal consolidation. Here we investigated whether the selective deprivation of slow wave sleep (SWS) or rapid eye movement (REM) sleep over an entire night would have a specific effect on consolidation in explicit and implicit memory tasks. Method: Participants completed a set...
Menghini, Deny; Carlesimo, Giovanni Augusto; Marotta, Luigi; Finzi, Alessandra; Vicari, Stefano
The reduced verbal long-term memory capacities often reported in dyslexics are generally interpreted as a consequence of their deficit in phonological coding. The present study was aimed at evaluating whether the learning deficit exhibited by dyslexics was restricted only to the verbal component of the long-term memory abilities or also involved…
Casey, P; Huntsdale, C; Angus, G; Janes, C
This study, using an information processing model of memory, made a detailed examination of the possible locus (loci) of any memory change in gravid and postpartum women using a battery of seven objective memory tests: implicit, incidental, explicit, semantic, short-term, working, and prospective memory. In addition, links were sought both between (a) self-reported data on sleep, health, and memory performance, and (b) these variables and objective memory performance. Five groups of women were tested (n = 22/23 per group), (1) primigravid, (2) multigravid, (3) postpartum, (4) non-pregnant parents with children, and (5) never been pregnant, on self-report and objective memory tests. The gravid and postpartum groups reported significantly more everyday forgetting than the non-pregnant groups but on the objective tests performed no differently from the non-pregnant groups on all tests. Sleep loss was a significant predictor of reported memory change, but not of any memory test performance, and may contribute to a perceived memory change. Pregnant women and new mothers generally should be confident of performing to their normal cognitive capabilities, but may be more affected than usual by a high cognitive load.
Smith, Jean Louise M.; Sáez, Leilani; Doabler, Christian T.
Students are frequently expected to complete multistep tasks within a range of academic or classroom routines and to do so independently. Students' ability to complete these tasks successfully may vary as a consequence of both their working-memory capacity and the conditions under which they are expected to learn. Crucial features in the design or…
Kerer, Manuela; Marksteiner, Josef; Hinterhuber, Hartmann; Mazzola, Guerino; Kemmler, Georg; Bliem, Harald R; Weiss, Elisabeth M
BACKGROUND/STUDY CONTEXT: Explicit memory for music was investigated by using a new test with 24 existing and 3 newly composed pieces. Ten patients with mild cognitive impairment (MCI) and 10 patients with early stage of Alzheimer's disease (AD) were compared with 23 healthy subjects, in terms of verbal memory of music by the identification of familiar music excerpts and the discrimination of distortion and original timbre of musical excerpts. MCI and Alzheimer's patients showed significantly poorer performances in tasks requiring verbal memory of musical excerpts than the healthy participants. For discrimination of musical excerpts, MCI and AD patients surprisingly performed significantly better than the healthy comparison subjects. Our results support the notion of a specialized memory system for music.
Dillon, Daniel G; Ritchey, Maureen; Johnson, Brian D; LaBar, Kevin S
The authors manipulated emotion regulation strategies at encoding and administered explicit and implicit memory tests. In Experiment 1, participants used reappraisal to enhance and decrease the personal relevance of unpleasant and neutral pictures. In Experiment 2, decrease cues were replaced with suppress cues that directed participants to inhibit emotion-expressive behavior. Across experiments, using reappraisal to enhance the personal relevance of pictures improved free recall. By contrast, attempting to suppress emotional displays tended to impair recall, especially compared to the enhance condition. Using reappraisal to decrease the personal relevance of pictures had different effects depending on picture type. Paired with unpleasant pictures, the decrease cue tended to improve recall. Paired with neutral stimuli, the decrease cue tended to impair recall. Emotion regulation did not affect perceptual priming. Results highlight dissociable effects of emotion regulation on explicit and implicit memory, as well as dissociations between regulation strategies with respect to explicit memory.
Bo, J; Borza, V.; Seidler, R. D.
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 adul...
Gilbertsen, Noreen D.; Belytschko, Ted
The implementation of a nonlinear explicit program on a vectorized, concurrent computer with shared memory is described and studied. The conflict between vectorization and concurrency is described and some guidelines are given for optimal block sizes. Several example problems are summarized to illustrate the types of speed-ups which can be achieved by reprogramming as compared to compiler optimization.
Buffett-Jerrott, Susan E; Stewart, Sherry H; Finley, G Allen; Loughlan, Heather Lee
Many laboratory-based studies indicate that benzodiazepines impair explicit memory performance, increase sedation, and impair attention. The present study was designed to extend prior lab-based findings to an applied setting in which the amnestic effects of benzodiazepines may be beneficial for users. In addition, the study extended the previous adult-focused research by examining the cognitive effects of benzodiazepines in children. The present study examined the use of a specific benzodiazepine (midazolam) as a premedicant among 40 children aged 4-6 years old having ear tube (myringotomy) surgery, who were randomly assigned to receive midazolam or placebo. Consistent with previous studies, the results indicated that midazolam causes significant amnesia on a cued recall task. In addition, free recall for post-drug events were also impaired by midazolam relative to placebo, indicating that benzodiazepine-induced amnesia occurs even for highly salient information. Overall, it appears that benzodiazepines do impair memory in a pediatric population. This amnesia was not secondary to the inattention and sedation also caused by midazolam administration. The theoretical and clinical implications of these findings are discussed, as are potential future studies.
Leritz, Elizabeth C; Grande, Laura J; Bauer, Russell M
Decades of research have provided substantial evidence of memory impairments in patients with temporal lobe epilepsy (TLE), including deficits in the encoding, storage, and retrieval of new information. These findings are not surprising, given the associated underlying neuroanatomy, including the hippocampus and surrounding medial temporal lobe structures. Because of its associated anatomic and cognitive characteristics, TLE has provided an excellent model by which to examine specific aspects of human memory functioning, including classic distinctions such as that between explicit and implicit memory. Various clinical and experimental research studies have supported the idea that both conscious and unconscious processes support memory functioning, but the role of relevant brain structures has been the subject of debate. This review is concerned with a discussion of the current status of this research and, importantly, how TLE can inform future studies of memory distinctions.
Parketny, Joanna; Towler, John; Eimer, Martin
Individuals with developmental prosopagnosia (DP) are strongly impaired in recognizing faces, but the causes of this deficit are not well understood. We employed event-related brain potentials (ERPs) to study the time-course of neural processes involved in the recognition of previously unfamiliar faces in DPs and in age-matched control participants with normal face recognition abilities. Faces of different individuals were presented sequentially in one of three possible views, and participants had to detect a specific Target Face ("Joe"). EEG was recorded during task performance to Target Faces, Nontarget Faces, or the participants' Own Face (which had to be ignored). The N250 component was measured as a marker of the match between a seen face and a stored representation in visual face memory. The subsequent P600f was measured as an index of attentional processes associated with the conscious awareness and recognition of a particular face. Target Faces elicited reliable N250 and P600f in the DP group, but both of these components emerged later in DPs than in control participants. This shows that the activation of visual face memory for previously unknown learned faces and the subsequent attentional processing and conscious recognition of these faces are delayed in DP. N250 and P600f components to Own Faces did not differ between the two groups, indicating that the processing of long-term familiar faces is less affected in DP. However, P600f components to Own Faces were absent in two participants with DP who failed to recognize their Own Face during the experiment. These results provide new evidence that face recognition deficits in DP may be linked to a delayed activation of visual face memory and explicit identity recognition mechanisms. Copyright © 2015 Elsevier Ltd. All rights reserved.
Bo, J; Borza, V; Seidler, R D
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.
Knight, Marisa; Ponzio, Allison
Although previous work has shown that emotion regulation strategies can influence memory, the mechanisms through which different strategies produce different memory outcomes are not well understood. We examined how two cognitive reappraisal strategies with similar elaboration demands but diverging effects on visual attention and emotional arousal influenced explicit memory for emotional stimuli and for the strategies used to evaluate the stimuli. At encoding, participants used reappraisal to increase and decrease the personal relevance of neutral and emotional pictures. In two experiments, recall accuracy was highest for emotional pictures featured on increase trials, intermediate for emotional pictures featured on look (respond naturally) trials, and lowest for emotional pictures featured on decrease trials. This recall pattern emerged after a short delay (15 min) and persisted over a longer delay (48 hr). Memory accuracy for the strategies used to evaluate the pictures showed a different pattern: Strategy memory was better for emotional pictures featured on decrease and increase trials than for pictures featured on look trials. Our findings show that the effects of emotion regulation on memory depend both on the particular strategy engaged and the particular aspect of memory being tested.
Zimmer, H D
Memory of size and orientation of objects was tested in explicit and implicit memory tests. Explicit memory was tested by object recognition and by recognition of the congruency of the changed sensory features. Implicit memory was tested by size assessment (Exps. 1 and 2), orientation judgement (Exps. 4 and 5), picture-fragment naming (Exp. 6), and classification (Exps. 3 and 7). Memory of sensory features was investigated by the comparison of performances of test-congruent with test-incongruent stimuli (i.e., same size or orientation vs. different size or orientation). The main result was a dissociation between these two tasks pertaining to the influence of sensory congruency on performance. However, it was in opposition to the usual relationship between the type of test and the perceptual similarity from study to test. In this study explicit, but not implicit, memory depended on sensory congruency. In the explicit tests performances were better when the stimuli were congruent than when they were incongruent. In the implicit test this variation had no influence. To get a repetition effect, it was important only that the object was repeated, and the size of this effect did not depend on sensory congruency. However, a change in another sensory feature--distortions of shape--strongly influenced the size of the repetition effect in the implicit test. Neither transfer-appropriate processing nor a system approach can easily explain this pattern of results. A multi-level, multi-token model is proposed to account for the different effects of sensory features in explicit and implicit memory.
Effting, M.; Salemink, E.; Verschuere, B.; Beckers, T.
Background and objectives: Avoidance behavior is central to several anxiety disorders. The current study tested whether avoidance behavior for spiders depends on a dynamic interplay between implicit and explicit processes, moderated by the availability to exert control through working memory
Boehm, Swen [ORNL; Pophale, Swaroop S [ORNL; Gorentla Venkata, Manjunath [Oak Ridge National Laboratory (ORNL)
The OpenSHMEM Library Specification has evolved consid- erably since version 1.0. Recently, non-blocking implicit Remote Memory Access (RMA) operations were introduced in OpenSHMEM 1.3. These provide a way to achieve better overlap between communication and computation. However, the implicit non-blocking operations do not pro- vide a separate handle to track and complete the individual RMA opera- tions. They are guaranteed to be completed after either a shmem quiet(), shmem barrier() or a shmem barrier all() is called. These are global com- pletion and synchronization operations. Though this semantic is expected to achieve a higher message rate for the applications, the drawback is that it does not allow fine-grained control over the completion of RMA operations. In this paper, first, we introduce non-blocking RMA operations with requests, where each operation has an explicit request to track and com- plete the operation. Second, we introduce interfaces to merge multiple requests into a single request handle. The merged request tracks multiple user-selected RMA operations, which provides the flexibility of tracking related communication operations with one request handle. Lastly, we explore the implications in terms of performance, productivity, usability and the possibility of defining different patterns of communication via merging of requests. Our experimental results show that a well designed and implemented OpenSHMEM stack can hide the overhead of allocating and managing the requests. The latency of RMA operations with requests is similar to blocking and implicit non-blocking RMA operations. We test our implementation with the Scalable Synthetic Compact Applications (SSCA #1) benchmark and observe that using RMA operations with requests and merging of these requests outperform the implementation using blocking RMA operations and implicit non-blocking operations by 49% and 74% respectively.
Schwegler, Kyrill; Ettlin, Dominik; Buser, Iris; Klaghofer, Richard; Goetzmann, Lutz; Buddeberg, Claus; Alon, Eli; Brügger, Mike; de Quervain, Dominique J-F
Remembering painful incidents has important adaptive value but may also contribute to clinical symptoms of posttraumatic stress disorder and chronic pain states. Because glucocorticoids are known to impair memory retrieval processes, we investigated whether cortisol affects recall of previously experienced pain in healthy young men. In a double-blind, placebo-controlled crossover study, 20 male participants were presented pictures, half of them combined with a heat-pain stimulus. The next day, the same pictures were shown in the absence of pain. Cortisol (20 mg) administered 1h before retention testing reduced recall of explicit contextual pain memory, whereas it did not affect pain threshold or pain tolerance. Copyright 2010 Elsevier Ltd. All rights reserved.
Romero, Nuria; Sanchez, Alvaro; Vázquez, Carmelo; Valiente, Carmen
This study examines the relationships between explicit and implicit self-esteem and self-referent memory biases in depression. We specifically tested the hypothesis that implicit self-esteem would influence depression-related memory biases via its association with explicit self-esteem. Self-esteem was assessed in patients with a current Major Depressive Disorder (MDD; n=38) and in a control group of participants who had never experienced depression (ND; n=40) by using explicit (Rosenberg Self-esteem Questionnaire) and implicit (Go/No-go Association Task) measures. A self-referent processing task of negative and positive adjectives was used to assess memory bias. Our analyses revealed that participants diagnosed with MDD showed lower levels of both explicit and implicit self-esteem in comparison to ND participants. MDD compared to ND participants also recalled a greater number of depressed self-referent adjectives and lower recall of positive self-referent information. Mediation analyses showed an indirect effect of explicit self-esteem on the relationship between implicit self-esteem and depression-related memory biases in the MDD group. These findings suggest an association between implicit and explicit self-esteem in depression that may result in negative cognitive processing, as reflected by self-referent memory biases. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Ray, Suchismita; Bates, Marsha E; Ely, Benjamin Martin
Alcohol's dissociation of implicit (unintentional) and explicit (intentional) memory processes in social drinkers was examined. It was hypothesized that an alcohol challenge would lower the percentage of words recalled and result in more retroactive interference in explicit recall tasks but would not lengthen reaction time in an implicit semantic priming task involving highly semantically similar words. Men and women completed all memory tasks in each of 2 counterbalanced sessions (alcohol challenge vs. no-alcohol) separated by 1 week. Alcohol significantly degraded processing in both explicit memory tasks, yet implicit semantic priming remained intact. A parallel distributed processing model that simulates semantic memory is presented. When this system is strongly activated, it does not appear to be altered during moderate alcohol intoxication. ((c) 2004 APA, all rights reserved)
Gareau, Alexandre; Gaudreau, Patrick
In previous research, autonomous motivation (AM) has been found to be associated with school achievement, but the relation has been largely heterogeneous across studies. AM has typically been assessed with explicit measures such as self-report questionnaires. Recent self-determination theory (SDT) research has suggested that converging implicit and explicit measures can be taken to characterize the integrative process in SDT. Drawing from dual-process theories, we contended that explicit AM is likely to promote school achievement when it is part of an integrated cognitive system that combines easily accessible mental representations (i.e., implicit AM) and efficient executive functioning. A sample of 272 university students completed a questionnaire and a lexical decision task to assess their explicit and implicit AM, respectively, and they also completed working memory capacity measures. Grades were obtained at the end of the semester to examine the short-term prospective effect of implicit and explicit AM, working memory, and their interaction. Results of moderation analyses have provided support for a synergistic interaction in which the association between explicit AM and academic achievement was positive and significant only for individuals with high level of implicit AM. Moreover, working memory was moderating the synergistic effect of explicit and implicit AM. Explicit AM was positively associated with academic achievement for students with average-to-high levels of working memory capacity, but only if their motivation operated synergistically with high implicit AM. The integrative process thus seems to hold better proprieties for achievement than the sole effect of explicit AM. Implications for SDT are outlined. © 2017 The British Psychological Society.
Eschen, A; Mattli, F; Sutter, C; Zöllig, J
The frequency of prospective and retrospective memory failures from six age groups was gathered using the Prospective and Retrospective Memory Questionnaire (PRMQ). Objective performance measures were obtained with a laboratory prospective memory task. Findings revealed more prospective than retrospective memory complaints in all age groups except in young children. While overall reported memory failures were similar in the adult groups, fewer failures were reported for the two children group...
In everyday life, motivation and learning are connected like music and dancing. Many educators realize this and work hard to improve their students' motivation. A motivated student may repeat and self-rehearse the content of a chapter more often, which leads to better learning. However, from a cognitive psychology point of view, it is still uncertain if motivation without differences in repetition or attention, affects episodic memory performance. That is, would a motivated student perform be...
Sherman, Stephanie M.; Buckley, Timothy P.; Baena, Elsa; Ryan, Lee
Many college students struggle to perform well on exams in the early morning. Although students drink caffeinated beverages to feel more awake, it is unclear whether these actually improve performance. After consuming coffee (caffeinated or decaffeinated), college-age adults completed implicit and explicit memory tasks in the early morning and late afternoon (Experiment 1). During the morning, participants ingesting caffeine demonstrated a striking improvement in explicit memory, but not impl...
Stephanie M Sherman
Full Text Available Many college students struggle to perform well on exams in the early morning. Although students drink caffeinated beverages to feel more awake, it is unclear whether these actually improve performance. After consuming coffee (caffeinated or decaffeinated, college-age adults completed implicit and explicit memory tasks in the early morning and late afternoon (Experiment 1. During the morning, participants ingesting caffeine demonstrated a striking improvement in explicit memory, but not implicit memory. Caffeine did not alter memory performance in the afternoon. In Experiment 2, participants engaged in cardiovascular exercise in order to examine whether increases in physiological arousal similarly improved memory. Despite clear increases in arousal, exercise did not improve memory performance compared to a stretching control condition. These results suggest that caffeine has a specific benefit for memory during students’ non-optimal time of day – early morning. These findings have real-world implications for students taking morning exams.
Sherman, Stephanie M; Buckley, Timothy P; Baena, Elsa; Ryan, Lee
Many college students struggle to perform well on exams in the early morning. Although students drink caffeinated beverages to feel more awake, it is unclear whether these actually improve performance. After consuming coffee (caffeinated or decaffeinated), college-age adults completed implicit and explicit memory tasks in the early morning and late afternoon (Experiment 1). During the morning, participants ingesting caffeine demonstrated a striking improvement in explicit memory, but not implicit memory. Caffeine did not alter memory performance in the afternoon. In Experiment 2, participants engaged in cardiovascular exercise in order to examine whether increases in physiological arousal similarly improved memory. Despite clear increases in physiological arousal, exercise did not improve memory performance compared to a stretching control condition. These results suggest that caffeine has a specific benefit for memory during students' non-optimal time of day - early morning. These findings have real-world implications for students taking morning exams.
Danley, William E., Jr.; Tanner, Don R.
Describes the development of a memory assessment instrument, the Perceptual Memory Test (PMT), which allows the nonverbal evaluation of various memory modalities. Compares the PMT with the Iowa Test of Musical Literacy and concludes that memory in a general sense might be important in performance on a musical assessment device. (FL)
Moon, Chung-Man; Yang, Jong-Chul; Jeong, Gwang-Woo
Generalized anxiety disorder (GAD) is associated with brain function and morphological alterations. This study investigated explicit verbal memory impairment in patients with GAD in terms of brain functional deficits in combination with morphologic changes. Seventeen patients with GAD and 17 healthy controls matched for age, sex, and education level underwent high-resolution T1-weighted MRI and fMR imaging at 3 T during explicit verbal memory tasks with emotionally neutral and anxiety-inducing words. In response to the neutral words, the patients showed significantly lower activities in the regions of the hippocampus (Hip), middle cingulate gyrus (MCG), putamen (Pu) and head of the caudate nucleus (HCd) compared with healthy controls. In response to the anxiety-inducing words, the patients showed significantly higher activities in the ventrolateral prefrontal cortex and precentral gyrus. However, they showed lower activities in the Hip, MCG, Pu and HCd. In addition, patients with GAD showed a significant reduction in gray matter volumes, especially in the regions of the Hip, midbrain, thalamus, insula and superior temporal gyrus, compared with healthy controls. This study examined a small sample sizes in each of the groups, and there was no consideration of a medication effect on brain activity and volume changes. This study provides evidence for the association between brain functional deficits and morphometric alterations in an explicit verbal memory task for patients with GAD. This finding is helpful for understanding explicit verbal memory impairment in connection with GAD symptoms. Copyright © 2015 Elsevier B.V. All rights reserved.
Francisco Lopera Restrepo
pseudodementia that can be ameliorated with antidepressive treatment. Objective: To describe explicit memory functioning in major depressive disorder. Materials and methods: Using the key words ";;major depression";;, ";;explicit memory";;, and ";;recollection memory";;, a search in PUBMED was carried out, selecting articles published after 2000. Additonal relevant scientific bibliography was also included. Results: In the neuroanatomy of the major depressive disorder fronto-subcortical networks are involved, among them prefrontal areas, the thalamus, basal ganglia, and the hippocampus. Atrophy of these structures may explain the persistence or chronicity of some cognitive symptoms of depression. Alterations of explicit, declarative or recollection memory are particularly important because of their frequency in subjects with one or more depressive episodes. The hippocampus is the cerebral structure more directly related with alterations of the explicit memory. In the hippocampus of adult animals continuous neurogenesis activity has been observed, and it is especially vulnerable to prolonged severe stress. Hippocampal volume has been found to be reduced in individuals with major depressive disorder, as compared to healthy ones. Even in the absence of marked volume reduction, there may be alterations in hippocampal function. Conclusion: Explicit memory is a psychological process with a very clear biological basis whose structure and function may be altered in the presence of major depression.
Archer, Charles J [Rochester, MN; Dozsa, Gabor [Ardsley, NY; Ratterman, Joseph D [Rochester, MN; Smith, Brian E [Rochester, MN
Methods, apparatus, and products are disclosed for performing an allreduce operation using shared memory that include: receiving, by at least one of a plurality of processing cores on a compute node, an instruction to perform an allreduce operation; establishing, by the core that received the instruction, a job status object for specifying a plurality of shared memory allreduce work units, the plurality of shared memory allreduce work units together performing the allreduce operation on the compute node; determining, by an available core on the compute node, a next shared memory allreduce work unit in the job status object; and performing, by that available core on the compute node, that next shared memory allreduce work unit.
Lang, J.W.B.; Zettler, Ingo; Ewen, C.
for implicit achievement). As a test of these theoretical ideas, we report a study in which employees (N = 241) filled out a questionnaire booklet and worked on an improved modern implicit motive measure, the operant motive test. Their supervisors rated their task and contextual performance. Results support 4...... of the 6 theoretical predictions and show that interactions between implicit motives and explicit traits increase the explained criterion variance in both task and contextual performance....... apply these ideas in the context of industrial and organizational psychology and propose that 2 explicit traits work as channels for the expression of 3 core implicit motives in task and contextual job performance (extraversion for implicit affiliation and implicit power; explicit achievement...
Bender, Michael; Woike, Barbara A; Burke, Christopher T; Dow, Emily A A
This online diary study investigated how motives interact with goal pursuit to predict daily autobiographical experiences. Participants (N =141) completed measures of implicit and explicit achievement, provided daily memories and reports of their goal pursuit during a three-week diary period. A stronger implicit achievement motive at the onset of the study was associated with more agentic (and fewer communal) autobiographical content. Goal progress was linked with using more agentic words, while goal attainability was related to using more communal words. Interactions between motives and goal pursuit on autobiographical memory suggests a trade-off: Favorable goal pursuit conditions may prompt people not motivated for achievement to shift their focus from agentic to communal themes, while individuals motivated for achievement maintain their priorities.
Volkova, Anna; Trehub, Sandra E.; Schellenberg, E. Glenn
We evaluated 6- and 7-month-olds' preference and memory for expressive recordings of sung lullabies. In Experiment 1, both age groups preferred lower-pitched to higher-pitched renditions of unfamiliar lullabies. In Experiment 2, infants were tested after 2 weeks of daily exposure to a lullaby at one pitch level. Seven-month-olds listened…
Salemink, Elske; Friese, Malte; Drake, Emily; Mackintosh, Bundy; Hoppitt, Laura
Interpretive biases play a crucial role in anxiety disorders. The aim of the current study was to examine factors that determine the relative strength of threat-related interpretive biases that are characteristic of individuals high in social anxiety. Different (dual process) models argue that both implicit and explicit processes determine information processing biases and behavior, and that their impact is moderated by the availability of executive resources such as working memory capacity (WMC). Based on these models, we expected indicators of implicit social anxiety to predict threat-related interpretive bias in individuals low, but not high in WMC. Indicators of explicit social anxiety should predict threat-related interpretive bias in individuals high, but not low in WMC. As expected, WMC moderated the impact of implicit social anxiety on threat-related interpretive bias, although the simple slope for individuals low in WMC was not statistically significant. The hypotheses regarding explicit social anxiety (with fear of negative evaluation used as an indicator) were fully supported. The clinical implications of these findings are discussed. PMID:23734123
Full Text Available Interpretive biases play a crucial role in anxiety disorders. The aim of the current study was to examine factors that determine the relative strength of threat-related interpretive biases that are characteristic of individuals high in social anxiety. Different (dual process models argue that both implicit and explicit processes determine information processing biases and behaviour, and that their impact is moderated by the availability of executive resources such as working memory capacity (WMC. Based on these models, we expected indicators of implicit social anxiety to predict threat-related interpretive bias in individuals low, but not high in WMC. Indicators of explicit social anxiety should predict threat-related interpretive bias in individuals high, but not low in WMC. As expected, WMC moderated the impact of implicit social anxiety on threat-related interpretive bias, although the simple slope for individuals low in WMC was not statistically significant. The hypotheses regarding explicit social anxiety (with fear of negative evaluation used as an indicator were fully supported. The clinical implications of these findings are discussed.
Full Text Available Introduction: The present post-eventual research study was conducted with the purpose of comparing the memory performance between two distinct groups of 50 healthy children and 50 attention deficit hyperactivity disorder (ADHD children (25 girls and 25 boys in Tehran with an age range of 10-12.Methods.The whole students were selected through simple random sampling method and were assessed in children's medical center, the Clinic of Roozbeh Hospital, and Tehran's Andishe primary school (both girls' and boys' branches. The applied tools for data gathering were the Benton test and Wechsler memory sub-test (form A.Results:The results showed a significant difference between Benton test scores and Wechsler memory sub-test scores (i.e. personal and general information, orientation, mind control, logical memory, repeating numbers straightly or reversely, learning and memory among healthy children and those with ADHD.Discussion:memory performance in children with ADHD was weaker than healthy children. In general, with regard to the memory deficit and attention disorder, these patients require both memory and attention rehabilitation for a better quality of l
Lang, Jonas W B; Zettler, Ingo; Ewen, Christian; Hülsheger, Ute R
Personality psychologists have long argued that explicit traits (as measured by questionnaires) channel the expression of implicit motives (as measured by coding imaginative verbal behavior) such that both interact in the prediction of relevant life outcome variables. In the present research, we apply these ideas in the context of industrial and organizational psychology and propose that 2 explicit traits work as channels for the expression of 3 core implicit motives in task and contextual job performance (extraversion for implicit affiliation and implicit power; explicit achievement for implicit achievement). As a test of these theoretical ideas, we report a study in which employees (N = 241) filled out a questionnaire booklet and worked on an improved modern implicit motive measure, the operant motive test. Their supervisors rated their task and contextual performance. Results support 4 of the 6 theoretical predictions and show that interactions between implicit motives and explicit traits increase the explained criterion variance in both task and contextual performance. (c) 2012 APA, all rights reserved.
Witt, Arnaud; Puspitawati, Ira; Vinter, Annie
Typically developing children aged 5 to 8 years were exposed to artificial grammar learning. Following an implicit exposure phase, half of the participants received neutral instructions at test while the other half received instructions making a direct, explicit reference to the training phase. We first aimed to assess whether implicit learning operated in the two test conditions. We then evaluated the differential impact of age on learning performances as a function of test instructions. The results showed that performance did not vary as a function of age in the implicit instructions condition, while age effects emerged when explicit instructions were employed at test. However, performance was affected differently by age and the instructions given at test, depending on whether the implicit learning of short or long units was assessed. These results suggest that the claim that the implicit learning process is independent of age needs to be revised. PMID:23326409
Yordanova, Juliana; Kirov, Roumen; Kolev, Vasil
Only some, but not all, individuals who practice tasks with dual structure, overt and covert, are able to comprehend consciously a hidden regularity. The formation of implicit representations of regularity has been proposed to be critical for subsequent awareness. However, explicit knowledge also has been predicted by the activation of executive control systems during task encoding. The present study analyzed performance patterns in participants who could comprehend task regularity and those who could not at delayed recall. Specifically, the role of practice-based knowledge of sequence for individual awareness was focused on. A lateralized variant of the visual serial response time task (SRTT) comprising structured and random blocks was practiced in implicit conditions by 109 participants before and after 10-h retention, with explicit knowledge about covert sequence tested thereafter. Sequence learning was quantified using the normalized difference between response speed in regular and subsequent random blocks. Patterns of performance dynamics were evaluated using response speed, response variability, and error rate. Major results demonstrate that (1) All participants who became aware of the sequence (solvers), gained practice-based sequence knowledge at learning or after retention, (2) Such knowledge also was accumulated during learning by participants who remained fully unaware about covert task structure, (3) Only in explicit solvers, however, was sequence-specific learning accompanied by a prominent increase in performance variability. (4) Specific features and dynamics of performance patterns distinguished different cognitive modes of SRTT processing, each of which supported subsequent knowledge awareness. It is concluded that a behavioral precursor of sequence awareness is the combination of speeded sequence processing and increased performance variability, pointing to an interaction between implicit and explicit processing systems. These results may
Full Text Available Only some, but not all, individuals who practice tasks with dual structure, overt and covert, are able to comprehend consciously a hidden regularity. The formation of implicit representations of regularity has been proposed to be critical for subsequent awareness. However, explicit knowledge also has been predicted by the activation of executive control systems during task encoding. The present study analysed performance patterns in participants who could comprehend task regularity and those who could not at delayed recall. Specifically, the role of practice-based knowledge of sequence for individual awareness was focused on.A lateralized variant of the visual serial response time task (SRTT comprising structured and random blocks was practiced in implicit conditions by 109 participants before and after 10-h retention, with explicit knowledge about covert sequence tested thereafter. Sequence learning was quantified using the normalized difference between response speed in regular and subsequent random blocks. Patterns of performance dynamics were evaluated using response speed, response variability, and error rate. Major results demonstrate that (1 All participants who became aware of the sequence (solvers, gained practice-based sequence knowledge at learning or after retention, (2 Such knowledge also was accumulated during learning by participants who remained fully unaware about covert task structure, (3 Only in explicit solvers, however, was sequence-specific learning accompanied by a prominent increase in performance variability. (4 Specific features and dynamics of performance patterns distinguished different cognitive modes of SRTT processing, each of which supported subsequent knowledge awareness.It is concluded that a behavioural precursor of sequence awareness is the combination of speeded sequence processing and increased performance variability, pointing to an interaction between implicit and explicit processing systems. These results
Colom, Roberto; Martinez-Molina, Agustin; Shih, Pei Chun; Santacreu, Jose
Multitasking performance is relevant in everyday life and job analyses highlight the influence of multitasking over several diverse occupations. Intelligence is the best single predictor of overall job performance and it is also related to individual differences in multitasking. However, it has been shown that working memory capacity (WMC) is…
Pearman, Ann; Trujillo, Amanda
Memory performance predictions are subjective estimates of possible memory task performance. The purpose of this study was to examine possible factors related to changes in word list performance predictions made by younger and older adults. Factors included memory self-efficacy, actual performance, and perceptions of performance. The current study…
Skodzik, Timo; Holling, Heinz; Pedersen, Anya
Memory problems are a frequently reported symptom in adult ADHD, and it is well-documented that adults with ADHD perform poorly on long-term memory tests. However, the cause of this effect is still controversial. The present meta-analysis examined underlying mechanisms that may lead to long-term memory impairments in adult ADHD. We performed separate meta-analyses of measures of memory acquisition and long-term memory using both verbal and visual memory tests. In addition, the influence of potential moderator variables was examined. Adults with ADHD performed significantly worse than controls on verbal but not on visual long-term memory and memory acquisition subtests. The long-term memory deficit was strongly statistically related to the memory acquisition deficit. In contrast, no retrieval problems were observable. Our results suggest that memory deficits in adult ADHD reflect a learning deficit induced at the stage of encoding. Implications for clinical and research settings are presented.
Aghaie, Reza; Zhang, Lawrence Jun
This study explored the impact of explicit teaching of reading strategies on English-as-a-foreign-language (EFL) students' reading performance in Iran. The study employed a questionnaire adapted from Chamot and O'Malley's (1994) cognitive and metacognitive strategies framework. To test the effects of explicit teaching of cognitive and…
Yogesh, Agrawel [Iowa State Univ., Ames, IA (United States)
This thesis studies memory bandwidth as a performance predictor of programs. The focus of this work is on computationally intensive programs. These programs are the most likely to access large amounts of data, stressing the memory system. Computationally intensive programs are also likely to use highly optimizing compilers to produce the fastest executables possible. Methods to reduce the amount of data traffic by increasing the average number of references to each item while it resides in the cache are explored. Increasing the average number of references to each cache item reduces the number of memory requests. Chapter 2 describes the DLX architecture. This is the architecture on which all the experiments were performed. Chapter 3 studies memory moves as a performance predictor for a group of application programs. Chapter 4 introduces a model to study the performance of programs in the presence of memory hierarchies. Chapter 5 explores some compiler optimizations that can help increase the references to each item while it resides in the cache.
Full Text Available To alleviate the performance degradation of conventional TCP in wireless networks, many schemes have been proposed so far. One category of such schemes is the Explicit Loss Notification (ELN scheme in which TCP senders are notified of wireless losses so as to avoid congestion control against those losses. Thus the key design factor of the ELN scheme is how to detect wireless losses accurately and rapidly. This paper proposes a new ELN scheme, in which wireless losses are detected by monitoring the operation of the wireless link layer. By exploiting such cross-layer design, the proposed scheme can detect wireless losses without additional transmission over the wireless link and thus achieves accurate detection with minimum delay. The proposed scheme additionally sends new information, that is, Explicit Retransmission Start Notification, in order to prevent spurious timeouts of the TCP senders. Furthermore, in order to handle packet reordering and avoid successive shrinking of a congestion window due to multiple packet drops, a new TCP modification is proposed. Through intensive simulations, it is demonstrated that the proposed scheme outperforms the other ELN schemes, and yields the throughput performance of more than 400% of TCP-Reno and 150% of Snoop in the considered environments.
Löwgren, Jonas; Eriksen, Mette Agger; Linde, Per
as an interpretation of palpability, comprising usability as well as patient empowerment and socially performative issues. We present a prototype environment for video recording during physiotherapeutical consultation which illustrates our current thoughts on explicit interaction and serves as material for further...
Jensen, Nicklas Bo; Larsen, Per; Ladelsky, Razya
Modern compilers use complex optimizations. It is often a problem for programmers to understand how source code should be written to enable optimizations. Interactive tools which guide programmers to higher performance are very important. We have developed such a tool that helps programmers modify...... their code to allow for aggressive optimization. In this paper, we extend it to support high level memory optimizations such as matrix reorganization. We evaluate the tool using two benchmarks and four dierent compilers. We show that it can guide the programmer to 22.9% higher performance....
Dzulkifli, Mariam Adawiah; Mustafar, Muhammad Faiz
Human cognition involves many mental processes that are highly interrelated, such as perception, attention, memory, and thinking. An important and core cognitive process is memory, which is commonly associated with the storing and remembering of environmental information. An interesting issue in memory research is on ways to enhance memory performance, and thus, remembering of information. Can colour result in improved memory abilities? The present paper highlights the relationship between co...
Altgassen, Mareike; Schmitz-H?bsch, Maren; Kliegel, Matthias
The purpose of the present study was to investigate event-based prospective memory performance in individuals with autism spectrum disorder and to explore possible relations between laboratory-based prospective memory performance and everyday performance. Nineteen children and adolescents with autism spectrum disorder and 19 matched neurotypical controls participated. The laboratory-based prospective memory test was embedded in a visuo-spatial working memory test and required participants to ...
Dzulkifli, Mariam Adawiah; Mustafar, Muhammad Faiz
Human cognition involves many mental processes that are highly interrelated, such as perception, attention, memory, and thinking. An important and core cognitive process is memory, which is commonly associated with the storing and remembering of environmental information. An interesting issue in memory research is on ways to enhance memory performance, and thus, remembering of information. Can colour result in improved memory abilities? The present paper highlights the relationship between colours, attention, and memory performance. The significance of colour in different settings is presented first, followed by a description on the nature of human memory. The role of attention and emotional arousal on memory performance is discussed next. The review of several studies on colours and memory are meant to explain some empirical works done in the area and related issues that arise from such studies.
Dzulkifli, Mariam Adawiah; Mustafar, Muhammad Faiz
Human cognition involves many mental processes that are highly interrelated, such as perception, attention, memory, and thinking. An important and core cognitive process is memory, which is commonly associated with the storing and remembering of environmental information. An interesting issue in memory research is on ways to enhance memory performance, and thus, remembering of information. Can colour result in improved memory abilities? The present paper highlights the relationship between colours, attention, and memory performance. The significance of colour in different settings is presented first, followed by a description on the nature of human memory. The role of attention and emotional arousal on memory performance is discussed next. The review of several studies on colours and memory are meant to explain some empirical works done in the area and related issues that arise from such studies. PMID:23983571
Sun, Lihua; Peräkylä, Jari; Holm, Katri; Haapasalo, Joonas; Lehtimäki, Kai; Ogawa, Keith H; Peltola, Jukka; Hartikainen, Kaisa M
Vagus nerve stimulation (VNS) is used for treating refractory epilepsy and major depression. While the impact of this treatment on seizures has been established, its impact on human cognition remains equivocal. The goal of this study is to elucidate the immediate effects of vagus nerve stimulation on attention, cognition, and emotional reactivity in patients with epilepsy. Twenty patients (12 male and 8 female; 45 ± 13 years old) treated with VNS due to refractory epilepsy participated in the study. Subjects performed a computer-based test of executive functions embedded with emotional distractors while their brain activity was recorded with electroencephalography. Subjects' cognitive performance, early visual event-related potential N1, and frontal alpha asymmetry were studied when cyclic vagus nerve stimulation was on and when it was off. We found that vagus nerve stimulation improved working memory performance as seen in reduced errors on a subtask that relied on working memory, odds ratio (OR) = 0.63 (95% confidence interval, CI [0.47, 0.85]) and increased N1 amplitude, F(1, 15) = 10.17, p = .006. In addition, vagus nerve stimulation resulted in longer reaction time, F(1, 16) = 8.23, p = .019, and greater frontal alpha asymmetry, F(1, 16) = 11.79, p = .003, in response to threat-related distractors. This is the first study to show immediate improvement in working memory performance in humans with clinically relevant vagus nerve stimulation. Furthermore, vagus nerve stimulation had immediate effects on emotional reactivity evidenced in behavior and brain physiology.
Siedlecki, Karen L
Visual perspective in autobiographical memories was examined in terms of reliability, consistency, and relationship to objective memory performance in a sample of 99 individuals. Autobiographical memories may be recalled from two visual perspectives--a field perspective in which individuals experience the memory through their own eyes, or an observer perspective in which individuals experience the memory from the viewpoint of an observer in which they can see themselves. Participants recalled nine word-cued memories that differed in emotional valence (positive, negative and neutral) and rated their memories on 18 scales. Results indicate that visual perspective was the most reliable memory characteristic overall and is consistently related to emotional intensity at the time of recall and amount of emotion experienced during the memory. Visual perspective is unrelated to memory for words, stories, abstract line drawings or faces.
Kaschel, Reiner; Kazén, Miguel; Kuhl, Julius
A modified event-based paradigm of prospective memory was applied to investigate intention initiation in older and younger participants under high versus low memory load (subsequent episodic word recall vs. recognition). State versus action orientation, a personality dimension related to intention enactment, was also measured. State-oriented persons show a superiority effect for the storage of intentions in an explicit format but have a paradoxical deficit in their actual enactment. We predicted an interaction between aging, personality, and memory load, with longer intention-initiation latencies and higher omission rates for older state-oriented participants under high memory load. Results were consistent with predictions and are interpreted according to current personality and prospective memory models of aging.
Benjamin R. Brown
Full Text Available An earlier investigation found that the performance of advanced students in a quantum mechanics course did not automatically improve from midterm to final exam on identical problems even when they were provided the correct solutions and their own graded exams. Here, we describe a study, which extended over four years, in which upper-level undergraduate students in a quantum physics course were given four identical problems in both the midterm exam and final exam. Approximately half of the students were given explicit incentives to correct their mistakes in the midterm exam. In particular, they could get back up to 50% of the points lost on each midterm exam problem. The solutions to the midterm exam problems were provided to all students in both groups but those who corrected their mistakes were provided the solution after they submitted their corrections to the instructor. The performance on the same problems on the final exam suggests that students who were given incentives to correct their mistakes significantly outperformed those who were not given an incentive. The incentive to correct the mistakes had greater impact on the final exam performance of students who had not performed well on the midterm exam.
Papassotiropoulos, Andreas; Stephan, Dietrich A; Huentelman, Matthew J; Hoerndli, Frederic J; Craig, David W; Pearson, John V; Huynh, Kim-Dung; Brunner, Fabienne; Corneveaux, Jason; Osborne, David; Wollmer, M Axel; Aerni, Amanda; Coluccia, Daniel; Hänggi, Jürgen; Mondadori, Christian R A; Buchmann, Andreas; Reiman, Eric M; Caselli, Richard J; Henke, Katharina; de Quervain, Dominique J-F
Human memory is a polygenic trait. We performed a genome-wide screen to identify memory-related gene variants. A genomic locus encoding the brain protein KIBRA was significantly associated with memory performance in three independent, cognitively normal cohorts from Switzerland and the United States. Gene expression studies showed that KIBRA was expressed in memory-related brain structures. Functional magnetic resonance imaging detected KIBRA allele-dependent differences in hippocampal activations during memory retrieval. Evidence from these experiments suggests a role for KIBRA in human memory.
Varnosfadrani, Azizollah Dabaghi; Basturkmen, Helen
The study looked at the effects of correction of learners' errors on learning of grammatical features. In particular, the manner of correction (explicit vs. implicit correction) was investigated. The study also focussed on the effectiveness of explicit and implicit correction of developmental early vs. developmental late features. Fifty-six…
Andringa, Sible; de Glopper, Kees; Hacquebord, Hilde
A classroom study was designed to test the hypothesis that explicit knowledge is used by second-language (L2) learners in a free written response task if that knowledge is present. Eighty-one 12-18-year-old learners of Dutch as an L2 took part in a computer-assisted language learning experiment receiving either explicit or implicit instruction…
St Clair-Thompson, Helen; Stevens, Ruth; Hunt, Alexandra; Bolder, Emma
Previous research has demonstrated close relationships between working memory and children's scholastic attainment. The aim of the present study was to explore a method of improving working memory, using memory strategy training. Two hundred and fifty-four children aged five to eight years were tested on measures of the phonological loop,…
The subject of this book is to introduce a model-based quantitative performance indicator methodology applicable for performance, cost and reliability optimization of non-volatile memories. The complex example of flash memories is used to introduce and apply the methodology. It has been developed by the author based on an industrial 2-bit to 4-bit per cell flash development project. For the first time, design and cost aspects of 3D integration of flash memory are treated in this book. Cell, array, performance and reliability effects of flash memories are introduced and analyzed. Key performance parameters are derived to handle the flash complexity. A performance and array memory model is developed and a set of performance indicators characterizing architecture, cost and durability is defined. Flash memories are selected to apply the Performance Indicator Methodology to quantify design and technology innovation. A graphical representation based on trend lines is introduced to support a requirement based pr...
Aben, L.; Kessel, M.A. van; Duivenvoorden, H.J.; Busschbach, J.J. van; Eling, P.A.T.M.; Bogert, M.A.; Ribbers, G.M.
Memory Self-Efficacy (MSE) has been shown to be related to memory performance and social participation in a healthy elderly population. This relation is unclear in stroke. As about 30% of all stroke survivors report memory complaints, there is an urgent need for effective treatment strategies.
Vandenbosch, L.; van Oosten, J.M.F.; Peter, J.
Little is known about how exposure to sexually explicit Internet material (SEIM) relates to a performance-focused orientation toward sex. Based on a three-wave panel study among adolescents (N = 1,022), we found that watching SEIM predicted a sexual performance orientation from Wave (W) 2 to W3, but
Full Text Available The present study aimed at investigating the effects of explicit and implicit recasts on Iranian EFL learners' acquisition of English relative clauses. For this purpose, 64 participants were selected out of 94 intermediate level EFL learners at Falagh language Institute, Rasht, Iran. To have homogenized groups, the researcher administered a language proficiency test (TOEFL. Then, the researchers assigned them randomly to the explicit recast group, implicit recast group, and control group. They carried out some information gap tasks within four sessions. One group received explicit recast, the other group received implicit recast and the control one got no corrective feedback, for the target linguistic errors during the task performance. A grammatical judgment test was applied as the pretest and immediate posttest. The results of a paired-samples t-test and analyses of variance (ANOVA showed that the scores of all three groups improved significantly overtime. However, the explicit recast group did significantly better than both the control group and the implicit recast group. The results of the study were elaborated in terms of counterbalance hypothesis and noticing hypothesis. The superiority of explicit recast implied a beneficial role for negative evidence in SLA and that explicit recast was a better choice than implicit recast in the L2 classroom.
Explicit symplectic integrators have been important tools for accurate and efficient approximations of mechanical systems with separable Hamiltonians. For the first time, the article proposes for arbitrary Hamiltonians similar integrators, which are explicit, of any even order, symplectic in an extended phase space, and with pleasant long time properties. They are based on a mechanical restraint that binds two copies of phase space together. Using backward error analysis, KAM theory, and addi...
Altgassen, A.M.; Schmitz-Hübsch, M.; Kliegel, M.
The purpose of the present study was to investigate event-based prospective memory performance in individuals with autism spectrum disorder and to explore possible relations between laboratory-based prospective memory performance and everyday performance. Nineteen children and adolescents with
Wright, Matthew J; Wong, Andrew L; Obermeit, Lisa C; Woo, Ellen; Schmitter-Edgecombe, Maureen; Fuster, Joaquín M
Traumatic brain injury (TBI) is associated with deficits in memory for the content of completed activities. However, TBI groups have shown variable memory for the temporal order of activities. We sought to clarify the conditions under which temporal order memory for activities is intact following TBI. Additionally, we evaluated activity source memory and the relationship between activity memory and functional outcome in TBI participants. Thus, we completed a study of activity memory with 18 severe TBI survivors and 18 healthy age- and education-matched comparison participants. Both groups performed eight activities and observed eight activities that were fashioned after routine daily tasks. Incidental encoding conditions for activities were utilized. The activities were drawn from two counterbalanced lists, and both performance and observation were randomly determined and interspersed. After all of the activities were completed, content memory (recall and recognition), source memory (conditional source identification), and temporal order memory (correlation between order reconstruction and actual order) for the activities were assessed. Functional ability was assessed via the Community Integration Questionnaire (CIQ). In terms of content memory, TBI participants recalled and recognized fewer activities than comparison participants. Recognition of performed and observed activities was strongly associated with social integration on the CIQ. There were no between- or within-group differences in temporal order or source memory, although source memory performances were near ceiling. The findings were interpreted as suggesting that temporal order memory following TBI is intact under conditions of both purposeful activity completion and incidental encoding, and that activity memory is related to functional outcomes following TBI.
Landaverde, Raphael; Zhang, Tiansheng; Coskun, Ayse K.; Herbordt, Martin
Managing memory between the CPU and GPU is a major challenge in GPU computing. A programming model, Unified Memory Access (UMA), has been recently introduced by Nvidia to simplify the complexities of memory management while claiming good overall performance. In this paper, we investigate this programming model and evaluate its performance and programming model simplifications based on our experimental results. We find that beyond on-demand data transfers to the CPU, the GPU is also able to re...
Isaki, Emi; Spaulding, Tammie J; Plante, Elena
The purpose of this study is to investigate the performance of adults with language-based learning disorders (L/LD) and normal language controls on verbal short-term and verbal working memory tasks. Eighteen adults with L/LD and 18 normal language controls were compared on verbal short-term memory and verbal working memory tasks under low, moderate, and high linguistic processing loads. Results indicate no significant group differences on all verbal short-term memory tasks and verbal working memory tasks with low and moderate language loads. Statistically significant group differences were found on the most taxing condition, the verbal working memory task involving high language processing load. The L/LD group performed significantly worse than the control group on both the processing and storage components of this task. These results support the limited capacity hypothesis for adults with L/LD. Rather than presenting with a uniform impairment in verbal memory, they exhibit verbal memory deficits only when their capacity limitations are exceeded under relatively high combined memory and language processing demands. The reader will (1) understand the relationship between increased linguistic demands and working memory, and (2) learn about working memory skills in adults with language learning disorders.
Cuttler, Carrie; Graf, Peter
Do interindividual differences in prospective memory task performance reflect individual differences in personality and lifestyle? Do the cognitive abilities known to change with age retain their power to predict episodic prospective memory task performance after controlling for personality and lifestyle variables, and do personality and lifestyle variables offer predictive power apart from that provided by cognitive ability measures? To answer these questions, we conducted a study with community-living healthy individuals (n= 141) between 18 and 81 years of age. They completed three different episodic prospective memory tasks--two laboratory tasks and one field task--as well as various measures of personality, lifestyle, and cognitive ability. The results indicated that personality and lifestyle reliably predicted who will succeed and who will fail on all three episodic prospective memory tasks. Conscientiousness predicted performance on two of the prospective memory tasks; socially prescribed perfectionism and neuroticism each predicted performance on one of the prospective memory tasks. Cognitive ability predicted performance on one of the laboratory prospective memory tasks but not on the other two prospective memory tasks. After we controlled for individual differences in personality and lifestyle variables, cognitive ability was no longer able to predict performance on the laboratory prospective memory task. By contrast, controlling for cognitive ability had no influence on the predictive power of the personality and lifestyle variables.
Altgassen, Mareike; Schmitz-Hübsch, Maren; Kliegel, Matthias
The purpose of the present study was to investigate event-based prospective memory performance in individuals with autism spectrum disorder and to explore possible relations between laboratory-based prospective memory performance and everyday performance. Nineteen children and adolescents with autism spectrum disorder and 19 matched neurotypical controls participated. The laboratory-based prospective memory test was embedded in a visuo-spatial working memory test and required participants to remember to respond to a cue-event. Everyday planning performance was assessed with proxy ratings. Although parents of the autism group rated their children's everyday performance as significantly poorer than controls' parents, no group differences were found in event-based prospective memory. Nevertheless, individual differences in laboratory-based and everyday performances were related. Clinical implications of these findings are discussed.
Full Text Available Understanding the referent of other's utterance by referring the contextual information helps in smooth communication. Although this pragmatic referential process can be observed even in infants, its underlying mechanism and relative abilities remain unclear. This study aimed to comprehend the background of the referential process by investigating whether the phonological loop affected the referent assignment. A total of 76 children (43 girls aged 3-5 years participated in a reference assignment task in which an experimenter asked them to answer explicit (e.g., "What color is this?" and ambiguous (e.g., "What about this?" questions about colorful objects. The phonological loop capacity was measured by using the forward digit span task in which children were required to repeat the numbers as an experimenter uttered them. The results showed that the scores of the forward digit span task positively predicted correct response to explicit questions and part of the ambiguous questions. That is, the phonological loop capacity did not have effects on referent assignment in response to ambiguous questions that were asked after a topic shift of the explicit questions and thus required a backward reference to the preceding explicit questions to detect the intent of the current ambiguous questions. These results suggest that although the phonological loop capacity could overtly enhance the storage of verbal information, it does not seem to directly contribute to the pragmatic referential process, which might require further social cognitive processes.
McManus, Kevin; Marsden, Emma
This study investigated the effectiveness of providing L1 explicit information (EI) with practice for making more accurate and faster interpretations of L2 French "Imparfait" (IMP). Two treatments were investigated: (a) "L2-only," providing EI about the L2 with L2 interpretation practice, and (b) "L2+L1," providing…
Full Text Available Background: Explicit and implicit memories have different cerebral origins and learning approaches. Defective emotional words processing in children with autism may affect the memory allocated to such words. The aim of this study was comparing two types of (explicit and implicit memories during processing the two types of (emotional and non-emotional words in autistic children and their healthy counterparts. Materials and Methods: The present cross sectional study was conducted on 14 autistic children, who had referred to Autism Medical Treatment Center on Tehran, and 14 healthy children in kindergartens and schools across Tehran. For the explicit memory, a list of words was presented to the subjects of our study and they were asked to repeat the words they heard one time immediately and one time with delay. For implicit memory, the subjects were asked to identify the heard words among the presented words. Statistical analysis was performed using two-way analysis of variance. Results: The results showed that the normal children have higher efficiency in explicit and implicit memory than the children with autism (p<0.01. The two-way analysis of memory type and word type showed that the former affects memory significantly (p<0.05 while word type had no significant effect. Conclusion: Autistic children suffer from impaired memory. This defect is higher in implicit memory than in the explicit memory. It is recommended to apply rehabilitation, training, learning approaches and also explicit memory for interventions of autistic children.
Gara, Alan; Salapura, Valentina; Wisniewski, Robert W
A device for copying performance counter data includes hardware path that connects a direct memory access (DMA) unit to a plurality of hardware performance counters and a memory device. Software prepares an injection packet for the DMA unit to perform copying, while the software can perform other tasks. In one aspect, the software that prepares the injection packet runs on a processing core other than the core that gathers the hardware performance data.
Stolpe, Karin; Bjorklund, Lars
This study aims to investigate the science content remembered by biology students 6 and 12 months after an ecology excursion. The students' memories were tested during a stimulated recall interview. The authors identified three different types of memories: "recall," "recognition" and "narratives." The "dual…
Hampson, Michelle; Driesen, Naomi R; Skudlarski, Pawel; Gore, John C; Constable, R. Todd
.... This study investigated the functional connectivity between the PCC and MFG/vACC during a working memory task and at rest by examining temporal correlations in magnetic resonance signal levels between the regions...
Brown, Franklin C.; Westerveld, Michael; Langfitt, John T.; Hamberger, Marla; Hamid, Hamada; Shinnar, Shlomo; Sperling, Michael R.; Devinsky, Orrin; Barr, William; Tracy, Joseph; Masur, David; Bazil, Carl W.; Spencer, Susan S.
This study examined the degree to which anxiety contributed to inconsistent material-specific memory difficulties among 243 temporal lobe epilepsy patients from the Multisite Epilepsy Study. Visual memory performance on the Rey Complex Figure Test (RCFT) was lower for those with high versus low level of anxiety, but was not found to be related to side of TLE. Verbal memory on the California Verbal Learning Test (CVLT) was significantly lower for left than right TLE patients with low anxiety, ...
Jia, Gangyong; Han, Guangjie; Wang, Hao; Yang, Xuan
In a cloud computing environment, the number of virtual machines (VMs) on a single physical server and the number of applications running on each VM are continuously growing. This has led to an enormous increase in the demand of memory capacity and subsequent increase in the energy consumption in the cloud. Lack of enough memory has become a major bottleneck for scalability and performance of virtualization interfaces in cloud computing. To address this problem, memory deduplication techniques which reduce memory demand through page sharing are being adopted. However, such techniques suffer from overheads in terms of number of online comparisons required for the memory deduplication. In this paper, we propose a static memory deduplication (SMD) technique which can reduce memory capacity requirement and provide performance optimization in cloud computing. The main innovation of SMD is that the process of page detection is performed offline, thus potentially reducing the performance cost, especially in terms of response time. In SMD, page comparisons are restricted to the code segment, which has the highest shared content. Our experimental results show that SMD efficiently reduces memory capacity requirement and improves performance. We demonstrate that, compared to other approaches, the cost in terms of the response time is negligible.
Van Swol, Lyn M
To assess performance and processes in collective and individual memory, participants watched two job candidates on video. Beforehand, half the participants were told they would be tested on their memory of the interviews, and the other half were asked to make a decision to hire one of the candidates. Afterwards, participants completed a recognition memory task in either a group or individual condition. Groups had better recognition memory than individuals. Individuals made more false positives than false negatives and groups exaggerated this. Post-hoc analysis found that groups only exaggerated the tendency towards false positives on items that reflected negatively on the job candidate. There was no significant difference between instruction conditions. When reaching consensus on the recognition task, groups tended to choose the correct answer if at least two members had the correct answer. This method of consensus is discussed as a factor in groups' superior memory performance.
Gaultney, J.F.; Kipp, K.; Kirk, G.
In acquiring mnemonic strategies, children may demonstrate a utilization deficiency phase in which they successfully execute a strategy but it does not facilitate memory performance. The present experiment suggests that utilization deficiencies are not a developmental phenomenon per se, but rather a byproduct of diminished working memory capacity…
Brown, Kirk Warren; Goodman, Robert J; Ryan, Richard M; Anālayo, Bhikkhu
Training in mindfulness, classically described as a receptive attentiveness to present events and experiences, has been shown to improve attention and working memory. Both are key to long-term memory formation, and the present three-study series used multiple methods to examine whether mindfulness would enhance episodic memory, a key form of long-term memory. In Study 1 (N = 143), a self-reported state of mindful attention predicted better recognition performance in the Remember-Know (R-K) paradigm. In Study 2 (N = 93), very brief training in a focused attention form of mindfulness also produced better recognition memory performance on the R-K task relative to a randomized, well-matched active control condition. Study 3 (N = 57) extended these findings by showing that relative to randomized active and inactive control conditions the effect of very brief mindfulness training generalized to free-recall memory performance. This study also found evidence for mediation of the mindfulness training-episodic memory relation by intrinsic motivation. These findings indicate that mindful attention can beneficially impact motivation and episodic memory, with potential implications for educational and occupational performance.
Kirk Warren Brown
Full Text Available Training in mindfulness, classically described as a receptive attentiveness to present events and experiences, has been shown to improve attention and working memory. Both are key to long-term memory formation, and the present three-study series used multiple methods to examine whether mindfulness would enhance episodic memory, a key form of long-term memory. In Study 1 (N = 143, a self-reported state of mindful attention predicted better recognition performance in the Remember-Know (R-K paradigm. In Study 2 (N = 93, very brief training in a focused attention form of mindfulness also produced better recognition memory performance on the R-K task relative to a randomized, well-matched active control condition. Study 3 (N = 57 extended these findings by showing that relative to randomized active and inactive control conditions the effect of very brief mindfulness training generalized to free-recall memory performance. This study also found evidence for mediation of the mindfulness training-episodic memory relation by intrinsic motivation. These findings indicate that mindful attention can beneficially impact motivation and episodic memory, with potential implications for educational and occupational performance.
Wu, Nan; Chen, Yulu; Yang, Jinhua; Li, Fei
The present study examined the role of working memory in the association between childhood obesity and academic performance, and further determined whether memory deficits in obese children are domain-specific to certain tasks or domain-general. A total of 227 primary school students aged 10-13 years were analyzed for weight and height, of which 159 children (44 "obese," 23 "overweight," and 92 "normal weight") filled out questionnaires on school performance and socioeconomic status. And then, all subjects finished three kinds of working memory tasks based on the digit memory task in 30 trials, which were image-generated with a series of numbers recall trial sets. After each trial set, subjects were given 5 s to recall and write down the numbers which hand appeared in the trial, in the inverse order in which they had appeared. The results showed there were significant academic performance differences among the three groups, with normal-weight children scoring higher than overweight and obese children after Bonferroni correction. A mediation model revealed a partial indirect effect of working memory in the relationship between obesity and academic performance. Although the performance of obese children in basic working memory tests was poorer than that of normal-weight children, they recalled more items than normal-weight children in working memory tasks involving with food/drink. Working memory deficits partially explain the poor academic performance of obese children. Those results indicated the obese children show domain-specific working memory deficits, whereas they recall more items than normal-weight children in working memory tasks associated with food/drink.
Wu, Nan; Chen, Yulu; Yang, Jinhua; Li, Fei
The present study examined the role of working memory in the association between childhood obesity and academic performance, and further determined whether memory deficits in obese children are domain-specific to certain tasks or domain-general. A total of 227 primary school students aged 10–13 years were analyzed for weight and height, of which 159 children (44 “obese,” 23 “overweight,” and 92 “normal weight”) filled out questionnaires on school performance and socioeconomic status. And then, all subjects finished three kinds of working memory tasks based on the digit memory task in 30 trials, which were image-generated with a series of numbers recall trial sets. After each trial set, subjects were given 5 s to recall and write down the numbers which hand appeared in the trial, in the inverse order in which they had appeared. The results showed there were significant academic performance differences among the three groups, with normal-weight children scoring higher than overweight and obese children after Bonferroni correction. A mediation model revealed a partial indirect effect of working memory in the relationship between obesity and academic performance. Although the performance of obese children in basic working memory tests was poorer than that of normal-weight children, they recalled more items than normal-weight children in working memory tasks involving with food/drink. Working memory deficits partially explain the poor academic performance of obese children. Those results indicated the obese children show domain-specific working memory deficits, whereas they recall more items than normal-weight children in working memory tasks associated with food/drink. PMID:28469593
Abdullah Talha Kabakus
Full Text Available The popularity of NoSQL databases has increased due to the need of (1 processing vast amount of data faster than the relational database management systems by taking the advantage of highly scalable architecture, (2 flexible (schema-free data structure, and, (3 low latency and high performance. Despite that memory usage is not major criteria to evaluate performance of algorithms, since these databases serve the data from memory, their memory usages are also experimented alongside the time taken to complete each operation in the paper to reveal which one uses the memory most efficiently. Currently there exists over 225 NoSQL databases that provide different features and characteristics. So it is necessary to reveal which one provides better performance for different data operations. In this paper, we experiment the widely used in-memory databases to measure their performance in terms of (1 the time taken to complete operations, and (2 how efficiently they use memory during operations. As per the results reported in this paper, there is no database that provides the best performance for all data operations. It is also proved that even though a RDMS stores its data in memory, its overall performance is worse than NoSQL databases.
Huntley, Jonathan; Bor, Daniel; Hampshire, Adam; Owen, Adrian; Howard, Robert
Chunking is a powerful encoding strategy that significantly improves working memory performance in normal young people. To investigate chunking in patients with mild Alzheimer's disease and in a control group of elderly people without cognitive impairment. People with mild Alzheimer's disease (n = 28) were recruited and divided according to Mini-Mental State Examination score into mild and very mild disease groups. A control group of 15 elderly individuals was also recruited. All participants performed digit and spatial working memory tasks requiring either unstructured sequences or structured sequences (which encourage chunking of information) to be recalled. The control group and both disease groups performed significantly better on structured trials of the digit working memory tasks, indicating successful use of chunking strategies to improve verbal working memory performance. The control and very mild disease groups also performed significantly better on structured trials of the spatial task, whereas those with mild disease demonstrated no significant difference between the structured and unstructured spatial conditions. The ability to use chunking as an encoding strategy to improve verbal working memory performance is preserved at the mild stage of Alzheimer's disease, whereas use of chunking to improve spatial working memory is impaired by this stage. Simple training in the use of chunking might be a beneficial therapeutic strategy to prolong working memory functioning in patients at the earliest stage of Alzheimer's disease.
Gara, Alan; Salapura, Valentina; Wisniewski, Robert W.
Hardware support for collecting performance counters directly to memory, in one aspect, may include a plurality of performance counters operable to collect one or more counts of one or more selected activities. A first storage element may be operable to store an address of a memory location. A second storage element may be operable to store a value indicating whether the hardware should begin copying. A state machine may be operable to detect the value in the second storage element and trigger hardware copying of data in selected one or more of the plurality of performance counters to the memory location whose address is stored in the first storage element.
Chi-Ming A. Chen
Full Text Available A relationship between working memory impairment, disordered neuronal oscillations, and abnormal prefrontal GABA function has been hypothesized in schizophrenia; however, in vivo GABA measurements and gamma band neural synchrony have not yet been compared in schizophrenia. This case–control pilot study (N = 24 compared baseline and working memory task-induced neuronal oscillations acquired with high-density electroencephalograms (EEGs to GABA levels measured in vivo with magnetic resonance spectroscopy. Working memory performance, baseline GABA level in the left dorsolateral prefrontal cortex (DLPFC, and measures of gamma oscillations from EEGs at baseline and during a working memory task were obtained. A major limitation of this study is a relatively small sample size for several analyses due to the integration of diverse methodologies and participant compliance. Working memory performance was significantly lower for patients than for controls. During the working memory task, patients (n = 7 had significantly lower amplitudes in gamma oscillations than controls (n = 9. However, both at rest and across working memory stages, there were significant correlations between gamma oscillation amplitude and left DLPFC GABA level. Peak gamma frequency during the encoding stage of the working memory task (n = 16 significantly correlated with GABA level and working memory performance. Despite gamma band amplitude deficits in patients across working memory stages, both baseline and working memory-induced gamma oscillations showed strong dependence on baseline GABA levels in patients and controls. These findings suggest a critical role for GABA function in gamma band oscillations, even under conditions of system and cognitive impairments as seen in schizophrenia.
Riby, Leigh M; Law, Anna S; McLaughlin, Jennifer; Murray, Jennifer
Previous research has found that the ingestion of glucose boosts task performance in the memory domain (including tasks tapping episodic, semantic, and working memory). The present pilot study tested the hypothesis that glucose ingestion would enhance performance on a test of prospective memory. In a between-subjects design, 56 adults ranging from 17 to 80 years of age performed a computerized prospective memory task and an attention (filler) task after 25 g of glucose or a sweetness-matched placebo. Blood glucose measurements were also taken to assess the impact of individual differences on glucose regulation. After the drink containing glucose, cognitive facilitation was observed on the prospective memory task after excluding subjects with impaired fasting glucose level. Specifically, subjects receiving glucose were 19% more accurate than subjects receiving a placebo, a trend that was marginally nonsignificant, F₁,₄₁ = 3.4, P = .07, but that had a medium effect size, d = 0.58. Subjects receiving glucose were also significantly faster on the prospective memory task, F₁,₃₅ = 4.8, P glucose (indicative of poor glucose regulation) was associated with slower prospective memory responding, F₁,₃₅ = 4.4, P memory and executive functioning can benefit from the increased provision of glucose to the brain. Copyright © 2011 Elsevier Inc. All rights reserved.
Ferreri, Laura; Rodriguez-Fornells, Antoni
Music represents a special type of reward involving the recruitment of the mesolimbic dopaminergic system. According to recent theories on episodic memory formation, as dopamine strengthens the synaptic potentiation produced by learning, stimuli triggering dopamine release could result in long-term memory improvements. Here, we behaviourally test whether music-related reward responses could modulate episodic memory performance. Thirty participants rated (in terms of arousal, familiarity, emotional valence, and reward) and encoded unfamiliar classical music excerpts. Twenty-four hours later, their episodic memory was tested (old/new recognition and remember/know paradigm). Results revealed an influence of music-related reward responses on memory: excerpts rated as more rewarding were significantly better recognized and remembered. Furthermore, inter-individual differences in the ability to experience musical reward, measured through the Barcelona Music Reward Questionnaire, positively predicted memory performance. Taken together, these findings shed new light on the relationship between music, reward and memory, showing for the first time that music-driven reward responses are directly implicated in higher cognitive functions and can account for individual differences in memory performance.
Returning and recurring cultural forms, ancestral incarnations, theatrical imaginations, and racial memories in African plays construct a specific kind of historicity - the conjuring of the dead and the revitalization of cosmic energy or spiritual power. These formations perpetuate the construction of Africa and African-ness ...
Osman, Homira; Sullivan, Jessica R
The objectives of this study were to determine (a) whether school-age children with typical hearing demonstrate poorer auditory working memory performance in multitalker babble at degraded signal-to-noise ratios than in quiet; and (b) whether the amount of cognitive demand of the task contributed to differences in performance in noise. It was hypothesized that stressing the working memory system with the presence of noise would impede working memory processes in real time and result in poorer working memory performance in degraded conditions. Twenty children with typical hearing between 8 and 10 years old were tested using 4 auditory working memory tasks (Forward Digit Recall, Backward Digit Recall, Listening Recall Primary, and Listening Recall Secondary). Stimuli were from the standardized Working Memory Test Battery for Children. Each task was administered in quiet and in 4-talker babble noise at 0 dB and -5 dB signal-to-noise ratios. Children's auditory working memory performance was systematically decreased in the presence of multitalker babble noise compared with quiet. Differences between low-complexity and high-complexity tasks were observed, with children performing more poorly on tasks with greater storage and processing demands. There was no interaction between noise and complexity of task. All tasks were negatively impacted similarly by the addition of noise. Auditory working memory performance was negatively impacted by the presence of multitalker babble noise. Regardless of complexity of task, noise had a similar effect on performance. These findings suggest that the addition of noise inhibits auditory working memory processes in real time for school-age children.
Huda S. Muhammad
Full Text Available The gap between CPU and memory speed has always been a critical concern that motivated researchers to study and analyze the performance of memory hierarchical architectures. In the early stages of the design cycle, performance evaluation methodologies can be used to leverage exploration at the architectural level and assist in making early design tradeoffs. In this paper, we use simulation platforms developed using the VisualSim tool to compare the performance of two memory architectures, namely, the Direct Connect architecture of the Opteron, and the Shared Bus of the Xeon multicore processors. Key variations exist between the two memory architectures and both design approaches provide rich platforms that call for the early use of virtual system prototyping and simulation techniques to assess performance at an early stage in the design cycle.
Schicktanz, Nathalie; Schwegler, Kyrill; Fastenrath, Matthias; Spalek, Klara; Milnik, Annette; Papassotiropoulos, Andreas; Nyffeler, Thomas; de Quervain, Dominique J-F
Cognitive functions, such as working memory, depend on neuronal excitability in a distributed network of cortical regions. It is not known, however, if interindividual differences in cortical excitability are related to differences in working memory performance. In the present transcranial magnetic stimulation study, which included 188 healthy young subjects, we show that participants with lower resting motor threshold, which is related to higher corticospinal excitability, had increased 2-back working memory performance. The findings may help to better understand the link between cortical excitability and cognitive functions and may also have important clinical implications with regard to conditions of altered cortical excitability.
Shrestha, Sunil; Su, Chun-Yi; White, Amanda M.; Manzano Franco, Joseph B.; Marquez, Andres; Feo, John T.
In the age of massive parallelism, the focus of performance analysis has switched from the processor and related structures to the memory and I/O resources. Adapting to this new reality, a performance analysis tool has to provide a way to analyze resource usage to pinpoint existing and potential problems in a given application. This paper provides an overview of the Memory Observant Data Analysis (MODA) tool, a memory-centric tool first implemented on the Cray XMT supercomputer. Throughout the paper, MODA's capabilities have been showcased with experiments done on matrix multiply and Graph-500 application codes.
Landaverde, Raphael; Zhang, Tiansheng; Coskun, Ayse K; Herbordt, Martin
Managing memory between the CPU and GPU is a major challenge in GPU computing. A programming model, Unified Memory Access (UMA), has been recently introduced by Nvidia to simplify the complexities of memory management while claiming good overall performance. In this paper, we investigate this programming model and evaluate its performance and programming model simplifications based on our experimental results. We find that beyond on-demand data transfers to the CPU, the GPU is also able to request subsets of data it requires on demand. This feature allows UMA to outperform full data transfer methods for certain parallel applications and small data sizes. We also find, however, that for the majority of applications and memory access patterns, the performance overheads associated with UMA are significant, while the simplifications to the programming model restrict flexibility for adding future optimizations.
Killough, Cynthia M; Thompson, Laura A; Morgan, Gin
Performing music in front of others can be stressful, even for experienced performers. The physiological effects of stress, namely, increases in cortisol and sympathetic nervous system activity, have been shown to have detrimental effects on cognition, particularly working memory. This study used an audition-like performance scenario to elicit a stress response in performers who differed in their degree of musical experience. We expected that participants with more musical experience would be better able to regulate their stress response, would report lower levels of anxiety, insecurity, and nervousness, and would show better working memory following the stressor, compared to participants with less musical experience. Although we did not find differences between more and less experienced performers in their sympathetic nervous system activity or their self-reported feelings of anxiety and nervousness, we did find some important differences: following the stressor, more experienced performers were less insecure, they showed better regulation of their cortisol response, and they demonstrated better working memory.
Shyles, Daniel [University of Tennessee (UT); Dongarra, Jack J. [University of Tennessee, Knoxville (UTK); Guidry, Mike W. [ORNL; Tomov, Stanimire Z. [ORNL; Billings, Jay Jay [ORNL; Brock, Benjamin A. [ORNL; Haidar Ahmad, Azzam A. [ORNL
Abstract—We demonstrate the systematic implementation of recently-developed fast explicit kinetic integration algorithms that solve efficiently N coupled ordinary differential equations (subject to initial conditions) on modern GPUs. We take representative test cases (Type Ia supernova explosions) and demonstrate two or more orders of magnitude increase in efficiency for solving such systems (of realistic thermonuclear networks coupled to fluid dynamics). This implies that important coupled, multiphysics problems in various scientific and technical disciplines that were intractable, or could be simulated only with highly schematic kinetic networks, are now computationally feasible. As examples of such applications we present the computational techniques developed for our ongoing deployment of these new methods on modern GPU accelerators. We show that similarly to many other scientific applications, ranging from national security to medical advances, the computation can be split into many independent computational tasks, each of relatively small-size. As the size of each individual task does not provide sufficient parallelism for the underlying hardware, especially for accelerators, these tasks must be computed concurrently as a single routine, that we call batched routine, in order to saturate the hardware with enough work.
Brown, Franklin C.; Westerveld, Michael; Langfitt, John T.; Hamberger, Marla; Hamid, Hamada; Shinnar, Shlomo; Sperling, Michael R.; Devinsky, Orrin; Barr, William; Tracy, Joseph; Masur, David; Bazil, Carl W.; Spencer, Susan S.
This study examined the degree to which anxiety contributed to inconsistent material-specific memory difficulties among 243 temporal lobe epilepsy patients from the Multisite Epilepsy Study. Visual memory performance on the Rey Complex Figure Test (RCFT) was lower for those with high versus low level of anxiety, but was not found to be related to side of TLE. Verbal memory on the California Verbal Learning Test (CVLT) was significantly lower for left than right TLE patients with low anxiety, but equally impaired for those with high anxiety. These results suggest that we can place more confidence in the ability of verbal memory tests like the CVLT to lateralize to left TLE for those with low anxiety, but that verbal memory will be less likely to produce lateralizing information for those with high anxiety. This suggests that more caution is needed when interpreting verbal memory tests for those with high anxiety. These results indicated that RCFT performance was significantly affected by anxiety and did not lateralize to either side, regardless of anxiety level. This study adds to the existing literature which suggests that drawing-based visual memory tests do not lateralize among TLE patients, regardless of anxiety level. PMID:24291525
Brown, Franklin C; Westerveld, Michael; Langfitt, John T; Hamberger, Marla; Hamid, Hamada; Shinnar, Shlomo; Sperling, Michael R; Devinsky, Orrin; Barr, William; Tracy, Joseph; Masur, David; Bazil, Carl W; Spencer, Susan S
This study examined the degree to which anxiety contributed to inconsistent material-specific memory difficulties among 243 patients with temporal lobe epilepsy from the Multisite Epilepsy Study. Visual memory performance on the Rey Complex Figure Test (RCFT) was poorer for those with high versus low levels of anxiety but was not found to be related to the TLE side. The verbal memory score on the California Verbal Learning Test (CVLT) was significantly lower for patients with left-sided TLE than for patients with right-sided TLE with low anxiety levels but equally impaired for those with high anxiety levels. These results suggest that we can place more confidence in the ability of verbal memory tests like the CVLT to lateralize to left-sided TLE for those with low anxiety levels, but that verbal memory will be less likely to produce lateralizing information for those with high anxiety levels. This suggests that more caution is needed when interpreting verbal memory tests for those with high anxiety levels. These results indicated that RCFT performance was significantly affected by anxiety and did not lateralize to either side, regardless of anxiety levels. This study adds to the existing literature which suggests that drawing-based visual memory tests do not lateralize among patients with TLE, regardless of anxiety levels. © 2013.
Jin, Hao-Qiang; Jost, Gabriele; Biegel, Bryan A. (Technical Monitor)
The purpose of this study is to evaluate the feasibility of remote memory access (RMA) programming on shared memory parallel computers. We discuss different RMA based implementations of selected CFD application benchmark kernels and compare them to corresponding message passing based codes. For the message-passing implementation we use MPI point-to-point and global communication routines. For the RMA based approach we consider two different libraries supporting this programming model. One is a shared memory parallelization library (SMPlib) developed at NASA Ames, the other is the MPI-2 extensions to the MPI Standard. We give timing comparisons for the different implementation strategies and discuss the performance.
Hülür, Gizem; Hertzog, Christopher; Pearman, Ann; Ram, Nilam; Gerstorf, Denis
Clinical diagnostic criteria for memory loss in adults typically assume that subjective memory ratings accurately reflect compromised memory functioning. Research has documented small positive between-person associations between subjective memory and memory performance in older adults. Less is known, however, about whether within-person fluctuations in subjective memory covary with within-person variance in memory performance and depressive symptoms. The present study applied multilevel models of change to nine waves of data from 27,395 participants of the Health and Retirement Study (HRS; mean age at baseline = 63.78; SD = 10.30; 58% women) to examine whether subjective memory is associated with both between-person differences and within-person variability in memory performance and depressive symptoms and explored the moderating role of known correlates (age, gender, education, and functional limitations). Results revealed that across persons, level of subjective memory indeed covaried with level of memory performance and depressive symptoms, with small-to-moderate between-person standardized effect sizes (0.19 for memory performance and 0.21 for depressive symptoms). Within individuals, occasions when participants scored higher than usual on a test of episodic memory or reported fewer-than-average depressive symptoms generated above-average subjective memory. At the within-person level, subjective memory ratings became more sensitive to within-person alterations in memory performance over time and those suffering from functional limitations were more sensitive to within-person alterations in memory performance and depressive symptoms. We take our results to suggest that within-person changes in subjective memory in part reflect monitoring flux in one’s own memory functioning, but are also influenced by flux in depressive symptoms. PMID:25244464
Regan, J. E.
Two hypotheses concerning the way in which short-term memory interacts with another task in a dual task situation are considered. It is noted that when two tasks are combined, the activity of controlling and organizing performance on both tasks simultaneously may compete with either task for a resource; this resource may be space in a central mechanism or general processing capacity or it may be some task-specific resource. If a special relationship exists between short-term memory and control, especially if there is an identity relationship between short-term and a central controlling mechanism, then short-term memory performance should show a decrement in a dual task situation. Even if short-term memory does not have any particular identity with a controlling mechanism, but both tasks draw on some common resource or resources, then a tradeoff between the two tasks in allocating resources is possible and could be reflected in performance. The persistent concurrence cost in memory performance in these experiments suggests that short-term memory may have a unique status in the information processing system.
Altgassen, A.M.; Kretschmer, A.; Schnitzspahn, K.M.
Studies on prospective memory (PM) development in adolescents point to age-related increases through to adulthood. The goal of the present study was to examine whether instructing adolescents to engage in an episodic prospection of themselves executing future actions (i.e., future thinking) when forming an intention would improve their PM performance and reduce age-related differences. Further, we set out to explore whether future thinking instructions result in stronger memory traces and/or ...
Sona Matloubi; Ali Mohammadzadeh; Zahra Jafari; Alireza Akbarzade Baghban
Background and Aim: Music exists in all cultures; many scientists are seeking to understand how music effects cognitive development such as comprehension, memory, and reading skills. More recently, a considerable number of neuroscience studies on music have been developed. This study aimed to investigate the effects of null and positive background music in comparison with silence on auditory-verbal memory performance.Methods: Forty young adults (male and female) with normal hearing, aged betw...
Alkozei, Anna; Smith, Ryan; Dailey, Natalie S; Bajaj, Sahil; Killgore, William D S
Acute exposure to light within the blue wavelengths has been shown to enhance alertness and vigilance, and lead to improved speed on reaction time tasks, possibly due to activation of the noradrenergic system. It remains unclear, however, whether the effects of blue light extend beyond simple alertness processes to also enhance other aspects of cognition, such as memory performance. The aim of this study was to investigate the effects of a thirty minute pulse of blue light versus placebo (amber light) exposure in healthy normally rested individuals in the morning during verbal memory consolidation (i.e., 1.5 hours after memory acquisition) using an abbreviated version of the California Verbal Learning Test (CVLT-II). At delayed recall, individuals who received blue light (n = 12) during the consolidation period showed significantly better long-delay verbal recall than individuals who received amber light exposure (n = 18), while controlling for the effects of general intelligence, depressive symptoms and habitual wake time. These findings extend previous work demonstrating the effect of blue light on brain activation and alertness to further demonstrate its effectiveness at facilitating better memory consolidation and subsequent retention of verbal material. Although preliminary, these findings point to a potential application of blue wavelength light to optimize memory performance in healthy populations. It remains to be determined whether blue light exposure may also enhance performance in clinical populations with memory deficits.
Full Text Available Acute exposure to light within the blue wavelengths has been shown to enhance alertness and vigilance, and lead to improved speed on reaction time tasks, possibly due to activation of the noradrenergic system. It remains unclear, however, whether the effects of blue light extend beyond simple alertness processes to also enhance other aspects of cognition, such as memory performance. The aim of this study was to investigate the effects of a thirty minute pulse of blue light versus placebo (amber light exposure in healthy normally rested individuals in the morning during verbal memory consolidation (i.e., 1.5 hours after memory acquisition using an abbreviated version of the California Verbal Learning Test (CVLT-II. At delayed recall, individuals who received blue light (n = 12 during the consolidation period showed significantly better long-delay verbal recall than individuals who received amber light exposure (n = 18, while controlling for the effects of general intelligence, depressive symptoms and habitual wake time. These findings extend previous work demonstrating the effect of blue light on brain activation and alertness to further demonstrate its effectiveness at facilitating better memory consolidation and subsequent retention of verbal material. Although preliminary, these findings point to a potential application of blue wavelength light to optimize memory performance in healthy populations. It remains to be determined whether blue light exposure may also enhance performance in clinical populations with memory deficits.
Berggren, Nick; Curtis, Hannah M; Derakshan, Nazanin
It is a widely observed finding that emotion and anxiety interact; highly stressed or anxious individuals show robust attentional biases towards external negative information. More generally, research has suggested that exposure to threatening stimuli, as well as the experience of acute stress, also may impair top-down attentional control and working memory. In the current study, we investigated how the influence of emotion and anxiety may interact to influence working memory performance. Participants were required to encode the orientation of four simple shapes, eight, or four shapes while filtering out four other irrelevant shapes from memory. Before memory displays, an irrelevant neutral or fearful face cue also was presented. Memory performance was found to interact with self-reported state anxiety and cue valence; on neutral cue trials, state anxiety was negatively correlated with performance. This effect was absent following a fear cue. In addition, filtering efficiency was negatively associated with state anxiety solely following a fear cue. Our findings suggest that state anxiety's influence to visual working memory can be strongly modulated by external signals to threat. Most crucially, rather than anxious individuals having greater difficulty rejecting external threatening information, we observed that external threat may in its own right generally impair filtering efficiency in anxious individuals.
Zanto, Theodore P; Gazzaley, Adam
Our ability to focus attention on task-relevant information and ignore distractions is reflected by differential enhancement and suppression of neural activity in sensory cortex (i.e., top-down modulation). Such selective, goal-directed modulation of activity may be intimately related to memory, such that the focus of attention biases the likelihood of successfully maintaining relevant information by limiting interference from irrelevant stimuli. Despite recent studies elucidating the mechanistic overlap between attention and memory, the relationship between top-down modulation of visual processing during working memory (WM) encoding, and subsequent recognition performance has not yet been established. Here, we provide neurophysiological evidence in healthy, young adults that top-down modulation of early visual processing (memory, motion direction and color. Moreover, attention to irrelevant stimuli was reflected neurally during the WM maintenance period as an increased memory load. These results suggest that neural enhancement of relevant information is not the primary determinant of high-level performance, but rather optimal WM performance is dependent on effectively filtering irrelevant information through neural suppression to prevent overloading a limited memory capacity.
Barral, Sandra; Cosentino, Stephanie; Costa, Rosann
Research to understand variability at the highest end of the cognitive performance distribution has been scarce. Our aim was to define a cognitive endophenotype based on exceptional episodic memory (EM) performance and to investigate familial aggregation of EM in families from the Long Life Family...... Study (LLFS). Using a sample of 1911 nondemented offspring of long-lived probands, we created a quantitative phenotype, EM (memory z ≥ 1.5), and classified LLFS families as EM and non-EM families based on the number of EM offspring. We then assessed differences in memory performance between LLFS...... relatives in the parental generation of EM families and those in non-EM families using multivariate analysis adjusted for APOE Apolipoprotein E genotype. LLFS relatives in the proband generation from EM families showed better EM performance than those from non-EM families (β = 0.74, standard error = 0.19, p...
Full Text Available The utilization of game elements in a non-game context is currently used in a vast range of different domains. However, research on game elements’ effects in cognitive tasks is still sparse. Thus, in this study we implemented three game elements, namely, progress bar, level indicator, and a thematic setting, in a working memory training task. We evaluated the impact of game elements on user performance and perceived state of flow when compared to a conventional version of the task. Participants interacting with game elements showed higher scores in the working memory training task than participants from a control group who completed the working memory training task without the game elements. Moreover, game elements facilitated the individuals’ performance closer to their maximum working memory capacity. Finally, the perceived flow did not differ between the two groups, which indicates that game elements can induce better performance without changing the perception of being “in the zone”, that is without an increase in anxiety or boredom. This empirical study indicates that certain game elements can improve the performance and efficiency in a working memory task by increasing users’ ability and willingness to train at their optimal performance level.
Vannest, Jennifer; Szaflarski, Jerzy P; Privitera, Michael D; Schefft, Bruce K; Holland, Scott K
Memory difficulties are a frequent cognitive complaint of patients with chronic epilepsy. Previous studies have suggested that the presence of a seizure focus causes reorganization of brain mechanisms underlying memory function. Here we examine whether seizure onset in the left hemisphere and onset in the right hemisphere have different effects on memory lateralization and whether longer duration of epilepsy is associated with increased lateralization of memory functions to the unaffected hemisphere. We hypothesized that hemisphere of onset and duration of epilepsy would influence plasticity of memory mechanisms, similar to the plasticity observed for language mechanisms. Healthy controls (HC, N = 10) and patients with epilepsy (N = 23, 11 with a left- and 12 with a right-hemisphere focus) performed a scene-encoding fMRI task at 4 T. Active voxels (relative to scrambled image viewing) were identified for each participant. Memory laterality indices (LIs) were calculated in three regions of interest (ROIs) designed on the basis of HC group data: a functional ROI, an anatomical-hippocampal ROI, and an anatomical-medial temporal ROI encompassing hippocampus and parahippocampal gyrus. In healthy controls, LIs were suggestive of slight left lateralization of encoding memory for pictures. Patients with right hemisphere epilepsy showed a nonsignificant increase in degree of left lateralization. In contrast, patients with left hemispheric epilepsy showed right-lateralized activation, differing significantly from controls and from patients with right hemispheric epilepsy. Neuropsychological measures of memory (WMS-III Story Recall) across epilepsy patients predicted LIs in the anatomical ROIs: higher scores were associated with more left-lateralized medial temporal fMRI activation. Neither age of onset nor duration of epilepsy was significantly related to LI. These results indicate that focal epilepsy may influence the functional neuroanatomy of memory function.
Chalabaev, Aïna; Brisswalter, Jeanick; Radel, Rémi; Coombes, Stephen A; Easthope, Christopher; Clément-Guillotin, Corentin
Previous evidence shows that stereotype threat impairs complex motor skills through increased conscious monitoring of task performance. Given that one-step motor skills may not be susceptible to these processes, we examined whether performance on a simple strength task may be reduced under stereotype threat. Forty females and males performed maximum voluntary contractions under stereotypical or nullified-stereotype conditions. Results showed that the velocity of force production within the first milliseconds of the contraction decreased in females when the negative stereotype was induced, whereas maximal force did not change. In males, the stereotype induction only increased maximal force. These findings suggest that stereotype threat may impair motor skills in the absence of explicit monitoring processes, by influencing the planning stage of force production.
Reaves, Sarah; Graham, Brittany; Grahn, Jessica; Rabannifard, Parissa; Duarte, Audrey
Whether we are explicitly listening to it or not, music is prevalent in our environment. Surprisingly, little is known about the effect of environmental music on concurrent cognitive functioning and whether young and older adults are differentially affected by music. Here, we investigated the impact of background music on a concurrent paired associate learning task in healthy young and older adults. Young and older adults listened to music or to silence while simultaneously studying face-name pairs. Participants' memory for the pairs was then tested while listening to either the same or different music. Participants also made subjective ratings about how distracting they found each song to be. Despite the fact that all participants rated music as more distracting to their performance than silence, only older adults' associative memory performance was impaired by music. These results are most consistent with the theory that older adults' failure to inhibit processing of distracting task-irrelevant information, in this case background music, contributes to their memory impairments. These data have important practical implications for older adults' ability to perform cognitively demanding tasks even in what many consider to be an unobtrusive environment. © The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: firstname.lastname@example.org.
Pearman, Ann; Lachman, Margie E
The current study examined cardiovascular reactivity and recovery during memory testing in a sample of 28 younger and 28 older adults. Heart rate (HR) levels were measured before, during, and after a memory test (word list recall). Contrary to prediction, older adults did not have a blunted cardiovascular response to memory tasks compared to younger adults. Word list recall performance was predicted by both Age and an Age x HR recovery interaction. As expected, younger adults performed better on the word list task than older adults. In addition, older adults with better posttest HR recovery performed significantly better than older adults with poor posttest HR recovery, whereas HR recovery differences in younger adults were inconsequential. These relationships were not affected by subjective appraisals of anxiety and task difficulty. Overall, cardiac dysregulation, seen here as low HR recovery, represents an important, potentially modifiable, factor in memory performance in older adults. In addition to being beneficial to overall health, interventions designed to help older adults regulate their HR responses may help offset certain memory declines.
Jiang, Cunmei; Lim, Vanessa K; Wang, Hang; Hamm, Jeff P
Music processing is influenced by pitch perception and memory. Additionally these features interact, with pitch memory performance decreasing as the perceived distance between two pitches decreases...
Brown, Benjamin R.; Mason, Andrew; Singh, Chandralekha
An earlier investigation found that the performance of advanced students in a quantum mechanics course did not automatically improve from midterm to final exam on identical problems even when they were provided the correct solutions and their own graded exams. Here, we describe a study, which extended over four years, in which upper-level…
In this paper we review the currently achievable performances of holographic memories stored in photorefractive crystals. We discuss the dependence of the memory performances on the material peculiarities in three major aspects: storage capacity, data transfer rate,and image fidelity. In the recent years the research at Beijing Polytechnic University on the photorefractive holographic storage has been focused to the optimization of the storage capacity and diffraction efficiency, as well as the influence of noises on the fidelity of reconstructed images. Our research shows again that the realization of volume holographic storage technology requests materials with perfect properties.
Wu, Nan; Chen, Yulu; YANG, JINHUA; Li, Fei
The present study examined the role of working memory in the association between childhood obesity and academic performance, and further determined whether memory deficits in obese children are domain-specific to certain tasks or domain-general. A total of 227 primary school students aged 10–13 years were analyzed for weight and height, of which 159 children (44 “obese,” 23 “overweight,” and 92 “normal weight”) filled out questionnaires on school performance and socioeconomic status. And then...
Yokosawa, Koichi; Kimura, Keisuke; Chitose, Ryota; Momiki, Takuya; Kuriki, Shinya
Alpha-band rhythm is thought to be involved in memory processes, similarly to other spontaneous brain rhythms. Ten right-handed healthy volunteers participated in our proposed sequential short-term memory task that provides a serial position effect in accuracy rate. We recorded alpha-band rhythms by magnetoencephalography during performance of the task and observed that the amplitude of the rhythm was suppressed dramatically in the memory recall period. The suppressed region was estimated to be in the occipital lobe, suggesting that alpha-band rhythm is suppressed by activation of the occipital attentional network. Additionally, the alpha-band suppression reflected accuracy rate, that is, the amplitude was suppressed more when recalling items with higher accuracy rate. The sensors with a significant correlation between alpha-band amplitude and accuracy rate were located widely from the frontal to occipital regions mainly in the right hemisphere. The results suggests that alpha-band rhythm is involved in memory recall and can be index of memory performance.
Sancho Pitarch, Jose Carlos [Los Alamos National Laboratory; Kerbyson, Darren [Los Alamos National Laboratory; Lang, Mike [Los Alamos National Laboratory
Increasing the core-count on current and future processors is posing critical challenges to the memory subsystem to efficiently handle concurrent memory requests. The current trend to cope with this challenge is to increase the number of memory channels available to the processor's memory controller. In this paper we investigate the effectiveness of this approach on the performance of parallel scientific applications. Specifically, we explore the trade-off between employing multiple memory channels per memory controller and the use of multiple memory controllers. Experiments conducted on two current state-of-the-art multicore processors, a 6-core AMD Istanbul and a 4-core Intel Nehalem-EP, for a wide range of production applications shows that there is a diminishing return when increasing the number of memory channels per memory controller. In addition, we show that this performance degradation can be efficiently addressed by increasing the ratio of memory controllers to channels while keeping the number of memory channels constant. Significant performance improvements can be achieved in this scheme, up to 28%, in the case of using two memory controllers with each with one channel compared with one controller with two memory channels.
Studte, Sara; Bridger, Emma; Mecklinger, Axel
Many studies have shown that sleep improves memory performance, and that even short naps during the day are beneficial. Certain physiological components of sleep such as spindles and slow-wave-sleep are thought to be particularly important for memory consolidation. The aim of this experiment was to reveal the role of naps for hippocampus-dependent associative memory (AM) and hippocampus-independent item memory (IM) alongside their corresponding ERP old/new effects. Participants learnt single words and word-pairs before performing an IM- and an AM-test (baseline). One group was subsequently allowed to nap (∼90min) while the other watched DVDs (control group). Afterwards, both groups performed a final IM- and AM-test for the learned stimuli (posttest). IM performance decreased for both groups, while AM performance decreased for the control group but remained constant for the nap group, consistent with predictions concerning the selective impact of napping on hippocampus-dependent recognition. Putative ERP correlates of familiarity and recollection were observed in the IM posttest, whereas only the later recollection-related effect was present in the AM test. Notably, none of these effects varied with group. Positive correlations were observed between spindle density during slow-wave-sleep and AM posttest performance as well as between spindle density during non-REM sleep and AM baseline performance, showing that successful learning and retrieval both before and after sleep relates to spindle density during nap sleep. Together, these results speak for a selective beneficial impact of naps on hippocampus-dependent memories. Copyright © 2015 Elsevier Inc. All rights reserved.
Vogels, WWA; Dekker, MR; Brouwer, WH; de Jong, R
The primary purpose of the study was to identify event-based prospective-memory tasks that provide sensitive and reliable tools for assessing effects of normal aging in prospective-memory performance. Four prospective-memory tasks were selected from the literature or were newly developed, with the
Mitropoulou, Vivian; Harvey, Phillip D; Zegarelli, Gayle; New, Antonia S; Silverman, Jeremy M; Siever, Larry J
Cognitive deficits consistently have been reported in schizophrenia patients and in patients with schizotypal personality disorder. For this study, the authors wanted to identify which of the domains of cognitive impairment represent "core" deficits of schizophrenia, comparing subjects with schizotypal personality disorder to two comparison groups: healthy volunteers and patients with personality disorders unrelated to schizophrenia. Three groups completed a neuropsychological battery: patients with DSM-III-R schizotypal personality disorder (N=82); patients with DSM-III-R personality disorders unrelated to schizophrenia (i.e., a personality disorder other than schizotypal, schizoid, or paranoid [N=44]); and healthy volunteers (N=63). The battery included the California Verbal Learning Test, Trailmaking Test parts A and B, the Dot test of working memory, the Stroop Color and Word Test, the Paced Auditory Serial Addition Test, the WMS visual reproduction test, and the WAIS-R vocabulary and block design. Normative standards for performance that controlled for age, gender, and education were created from the scores of the healthy volunteers. Overall, schizotypal personality disorder patients performed significantly worse than the healthy volunteers and those with personality disorders unrelated to schizophrenia. Specifically, patients with schizotypal personality disorder demonstrated impaired performance on the Paced Auditory Serial Addition Test, WMS visual reproduction test, Dot test, and California Verbal Learning Test. In addition, in a regression analysis, performance on the Paced Auditory Serial Addition Test demonstrated the largest effect size. Indeed, it accounted for unique variance above and beyond all other cognitive measures, since controlling for Paced Auditory Serial Addition Test performance abolished group differences across all other measures. Patients with schizotypal personality disorder demonstrated moderate cognitive impairment compared with
Irwin, Rita L.; Rogers, Tony; Wan, Yuh-Yao
Addresses the need for making connections between cultures, especially among Aboriginal and dominant cultures. Focuses on these themes: cultural memory, cultural performance, and cultural translation. Highlights three Aboriginal cultures on three continents (South Australia, Canada, and Taiwan) to encourage art educators and students to engage in…
Jackson, Margaret C.; Linden, David E. J.; Roberts, Mark V.; Kriegeskorte, Nikolaus; Haenschel, Corinna
A number of studies have shown that visual working memory (WM) is poorer for complex versus simple items, traditionally accounted for by higher information load placing greater demands on encoding and storage capacity limits. Other research suggests that it may not be complexity that determines WM performance per se, but rather increased…
Travis, Scott; Coupland, Nicholas J; Silversone, Peter H; Huang, Yushan; Fujiwara, Esther; Carter, Rawle; Seres, Peter; Malykhin, Nikolai V
Magnetic resonance imaging (MRI) has shown lower hippocampal volume in major depressive disorder (MDD). Patients with MDD have consistently demonstrated worse performance than healthy controls a number of memory tests. Memory functions within the hippocampus in healthy younger subjects appear to be linked to cornu ammonis (CA1-3) and dentate gyrus (DG) subfields. Therefore, the main goal of the present study was to investigate whether memory deficits in MDD patients are related to reduction in hippocampal subfields volumes, particularly DG and CA 1-3. 15 MDD patients meeting DSM-IV criteria for MDD with moderate or severe episodes were recruited, together with 15 healthy controls. We used T2-weighted 2D Fast Spin Echo (FSE) and T1-weighted 3D MPRAGE sequences at 4.7 T to compare hippocampal subfield volumes at 0.09 μl voxel volume. Participants were administered the Wechsler Memory Scale. MDD patients underperformed in several episodic visual memory tasks, as well as in visual working memory, compared to healthy controls. Global hippocampal volumes were similar between groups; however, MDD patients showed significantly reduced DG volumes within the hippocampal body. Duration of depression correlated with MDD patients׳ total volumes in the hippocampal body and CA1-3 and DG subfields within it. Our study sample was relatively small and the majority of patients were on antidepressant treatment. Our findings suggest that DG volumes in particular may be worthy of further study to further elucidate their precise role in MDD, both by itself as well as in relation to memory. Copyright © 2014 Elsevier B.V. All rights reserved.
National Aeronautics and Space Administration — We propose a comprehensive and systematic contingency plan generation framework to deal with lost communication in UAVs. ATC regulations are explicitly incorporated...
Full Text Available In order to compare the use of a structured self-report questionnaire with direct questioning about memory problems, 71 healthy and independent aged individuals (63 women from the community without risk factors for cognitive deficits were objectively asked about subjective memory complaints (SMC, given the Memory Complaint Questionnaire (MAC-Q and then submitted to the Rey Auditory Verbal Learning Test (RAVLT. SMC positively correlated with higher scores on MAC-Q, although a significant percentage of the sample had SMC and lower scores on MAC-Q and also no SMC and higher scores on MAC-Q. Performance on RAVLT was significantly worse (p<0.05 for the group presenting SMC but not for the group with higher scores on the MAC-Q. We conclude that direct questioning maybe more clinically significant than a self report questionnaire, at least for elderly persons from the community without risk factors for cognitive decline or depression.
Donohoe, R T; Benton, D
The hypothesis that the ability to control blood glucose levels influence memory and other aspects of cognition was considered. Individual differences in the ability to control blood glucose were measured by giving a glucose tolerance test (GTT) to 46 young adult females. A factor analysis of a series of measures of glucose tolerance produced four dimensions. A week later, having eaten their normal breakfast, they took tests of memory, reaction times and vigilance. The speed with which blood glucose increased, having its lowest point in the GTT, was associated with memory measured a week later. While performing the tests those with higher levels of blood glucose on arrival in the laboratory had quicker reaction times when monitoring eight but not four, two or one lamps. The finding was interpreted as demonstrating that higher levels of blood glucose specially influence tasks placing higher demands on the brain.
Full Text Available Background and Aim: Music exists in all cultures; many scientists are seeking to understand how music effects cognitive development such as comprehension, memory, and reading skills. More recently, a considerable number of neuroscience studies on music have been developed. This study aimed to investigate the effects of null and positive background music in comparison with silence on auditory-verbal memory performance.Methods: Forty young adults (male and female with normal hearing, aged between 18 and 26, participated in this comparative-analysis study. An auditory and speech evaluation was conducted in order to investigate the effects of background music on working memory. Subsequently, the Rey auditory-verbal learning test was performed for three conditions: silence, positive, and null music.Results: The mean score of the Rey auditory-verbal learning test in silence condition was higher than the positive music condition (p=0.003 and the null music condition (p=0.01. The tests results did not reveal any gender differences.Conclusion: It seems that the presence of competitive music (positive and null music and the orientation of auditory attention have negative effects on the performance of verbal working memory. It is possibly owing to the intervention of music with verbal information processing in the brain.
Novick, Andrew M; Miiller, Leah C; Forster, Gina L; Watt, Michael J
Adolescent social stress is associated with increased incidence of mental illnesses in adulthood that are characterized by deficits in cognitive focus and flexibility. Such enhanced vulnerability may be due to psychosocial stress-induced disruption of the developing mesocortical dopamine system, which plays a fundamental role in facilitating complex cognitive processes such as spatial working memory. Adolescent rats exposed to repeated social defeat as a model of social stress develop dopaminergic hypofunction in the medial prefrontal cortex as adults. To evaluate a direct link between adolescent social stress and later deficits in cognitive function, the present study tested the effects of adolescent social defeat on two separate tests of spatial working memory performance. Adult rats exposed to adolescent social defeat and their controls were trained on either the delayed win-shift task or the delayed alternating T-Maze task and then challenged with various delay periods. To evaluate potential differences in motivation for the food reward used in memory tasks, consumption and conditioned place preference for sweetened condensed milk were tested in a separate cohort of previously defeated rats and controls. Compared to controls, adult rats defeated in adolescence showed a delay-dependent deficit in spatial working memory performance, committing more errors at a 90 s and 5 min delay period on the T-maze and win-shift tasks, respectively. Observed memory deficits were likely independent of differences in reward motivation, as conditioned place preference for the palatable food used on both tasks was similar between the adolescent social defeat group and control. The results demonstrate that severe social stressors during adolescence can produce long term deficits in aspects of cognitive function. Given the dependence of spatial working memory on prefrontal dopamine, pharmacologically reversing dopaminergic deficiencies caused by adolescent social stress has the
Yuri G. Pavlov
Full Text Available The aim of this research is to study the relationship betweenfrontal midline theta rhythm changes and individual differences in working memory performance.Methods. The methods involve behavioural testing on the basis of the program for a presentation of stimulus and registration of answers «PsyTask»; method of EEG (electroencephalography; a technique of measurement of efficiency of working memory; the comparative analysis. Software packages EEGLab for Matlab and Fieldtrip are applied while data processing.Results. After the behavioral test all subjects were separated into 2 groups according to their performance: with «highly productive» and «low productive» memory. Specially prepared author’s complete set of the tasks which complexity varied from average to ultrahigh level was offered to participants of experiment –students and employees of the Ural Federal University and Ural Legal Institute of the Ministry of Internal Affairs. Working memory tasks included sets of verbal stimuli for memorizing in strict order without any mental manipulation and sets of similar stimuli for memorizing in alphabetical order (with manipulations. Measured characteristics of theta-rhythm of EEG during information deduction in memory were compared of two groups’ representatives. The obtained data has shown rather uniform and similar dynamics of decrease in quantity of right answers in process of increasing tasks’ complexity. However, changes of a thetarhythm in different groups had sharply expressed distinctions. «Highly productive» examinees have systematic expansion of a theta-rhythm in the central assignments with stabilisation on the most difficult tasks; «low productive» – while tasks performance of average complexity, a sharp falling of theta-rhythm activity is observed after achievement of its maximum activation.Scientific novelty. The working memory «overload» effect and its EEG correlates are demonstrated on a big sample of
Full Text Available This study investigates the influence of an actual music stand on the evaluation of a videotaped audio-visual solo instrumental performance. Previous research has provided evidence that the presence of a score or music stand (obstructing the audience's view of the performer might negatively influence the evaluation of the performance. However, due to methodological ambiguities, results in previous studies cannot be regarded as definitive. Thus, we conducted a replication study of Williamon (1999 with better control over confounding variables (e.g., varying levels of technical proficiency in different conditions. A violoncello player performed two pieces for solo instrument: once with a music stand on stage (pretending to play from score and once without. The level of technical proficiency was kept constant in both performance presentations by the use of a pre-recorded, well-rehearsed performance from memory. Audio tracks were synchronized with the performance movements in a playback paradigm. Based on the performance evaluations from a web-based experiment (N = 471 participants, we found a significant but small effect size for the main effect of performance presentation (with vs. without music stand (d = 0.23. We conclude that the audience's appreciation of a particular performance from memory might be based on factors other than the objective performance quality.
Full Text Available Executive functioning (e.g., working memory is tightly intertwined with self-regulation. For example, food cue-elicited craving has been found to impair working memory performance. Furthermore, current dieters have been found to show lower working memory performance than non-dieters. Recent research, however, suggests that it is crucial to consider dieting success in addition to current dieting status or restrained eating in order to reveal cognitive mechanisms that are associated with successful eating-related self-regulation. The current study investigated food cue-related working memory performance as a function of dieting status and dieting success in female students. Participants performed an n-back task with pictures of food and neutral objects. Reaction time in response to food pictures was slower than in response to neutral pictures, whereas omission errors did not differ between picture types. Current food craving was increased after performing the food block, but not after the neutral block. There was an indirect effect of current dieting status on higher food craving after the food block, which was mediated by slower reaction time to food vs. neutral pictures. Furthermore, higher dieting success was associated with fewer omission errors in the food vs. neutral block in current dieters. There were no relationships of restrained eating with current food craving and task performance. Results further highlight the need to differentiate between successful and unsuccessful dieting in addition to current dieting status or restrained eating when examining possible mechanisms of overeating or successful restraint. Although palatable food cues induce food craving regardless of dieting success, they may boost executive functioning in successful dieters, which helps them to overcome these temptations.
Altgassen, Mareike; Kretschmer, Anett; Schnitzspahn, Katharina Marlene
Studies on prospective memory (PM) development in adolescents point to age-related increases through to adulthood. The goal of the present study was to examine whether instructing adolescents to engage in an episodic prospection of themselves executing future actions (i.e., future thinking) when forming an intention would improve their PM performance and reduce age-related differences. Further, we set out to explore whether future thinking instructions result in stronger memory traces and/or stronger cue-context associations by evaluating retrospective memory for the PM cues after task completion and monitoring costs during PM task processing. Adolescents and young adults were allocated to either the future thinking, repeated-encoding or standard condition. As expected, adolescents had fewer correct PM responses than young adults. Across age groups, PM performance in the standard condition was lower than in the other encoding conditions. Importantly, the results indicate a significant interaction of age by encoding condition. While adolescents benefited most from future thinking instructions, young adults performed best in the repeated-encoding condition. The results also indicate that the beneficial effects of future thinking may result from deeper intention-encoding through the simulation of future task performance.
A storage scheme based on racetrack memory, where the information can be coded in a domain or a skyrmion, seems to be an alternative to conventional hard disk drive for high density storage. Here, we perform a full micromagnetic study of the performance of synthetic antiferromagnetic (SAF) racetrack memory in terms of velocity and sensitivity to defects by using experimental parameters. We find that, to stabilize a SAF skyrmion, the Dzyaloshinskii–Moriya interaction in the top and the bottom ferromagnet should have an opposite sign. The velocity of SAF skyrmions and SAF Néel domain walls are of the same order and can reach values larger than 1200 m s−1 if a spin–orbit torque from the spin-Hall effect with opposite sign is applied to both ferromagnets. The presence of disordered anisotropy in the form of randomly distributed grains introduces a threshold current for both SAF skyrmions and SAF domain walls motions.
Heineken, E; Gekeler, C
Memory achievement is generally confounded with motivational factors in memory research. Therefore, the interpretation of age specific differences in recall renders difficult. The effect of a mnemonic device (method of loci) on recall is studied in a multitrial free recall experiment with 48 seniors aged from 60 to 92. Recall, performance in "Pauli"-tasks as an indicator of general achievement motivation, and subjective organization are measured. The experiment is planned as a three-factorial randomized group design with the factors "mnemonic device", "age", and "concreteness of learning material". The mnemonic device has a strong effect on recall as well as on performance "Pauli"-tasks. Its effect on recall is attributed to the increased achievement motivation.
Full Text Available Working memory (WM represents the brain's ability to maintain information in a readily available state for short periods of time. This study examines the resting-state cortical activity patterns that are most associated with performance on a difficult working-memory task.Magnetoencephalographic (MEG band-passed (delta/theta (1-7 Hz, alpha (8-13 Hz, beta (14-30 Hz and sensor based regional power was collected in a population of adult men (18-28 yrs, n = 24 in both an eyes-closed and eyes-open resting state. The normalized power within each resting state condition as well as the normalized change in power between eyes closed and open (zECO were correlated with performance on a WM task. The regional and band-limited measures that were most associated with performance were then combined using singular value decomposition (SVD to determine the degree to which zECO power was associated with performance on the three-back verbal WM task.Changes in power from eyes closed to open revealed a significant decrease in power in all band-widths that was most pronounced in the posterior brain regions (delta/theta band. zECO right posterior frontal and parietal cortex delta/theta power were found to be inversely correlated with three-back working memory performance. The SVD evaluation of the most correlated zECO metrics then provided a singular measure that was highly correlated with three-back performance (r = -0.73, p<0.0001.Our results indicate that there is an association between WM performance and changes in resting-state power (right posterior frontal and parietal delta/theta power. Moreover, an SVD of the most associated zECO measures produces a composite resting-state metric of regional neural oscillatory power that has an improved association with WM performance. To our knowledge, this is the first investigation that has found that changes in resting state electromagnetic neural patterns are highly associated with verbal working memory
Wang, Jinn-Rong; Hsieh, Shulan
The present study aimed to investigate the effectiveness of the frontal-midline theta (fmθ) activity uptraining protocol on attention and working memory performance of older and younger participants. Thirty-two participants were recruited. Participants within each age group were randomly assigned to either the neurofeedback training (fmθ uptraining) group or the sham-neurofeedback training group. There was a significant improvement in orienting scores in the older neurofeedback training group. In addition, there was a significant improvement in conflict scores in both the older and young neurofeedback training groups. However, alerting scores failed to increase. In addition, the fmθ training was found to improve working memory function in the older participants. The results further showed that fmθ training can modulate resting EEG for both neurofeedback groups. Our study demonstrated that fmθ uptraining improved attention and working memory performance and theta activity in the resting state for normal aging adults. In addition, younger participants also benefited from the present protocol in terms of improving their executive function. The current findings contribute to a better understanding of the mechanisms underlying neurofeedback training in cognitive function, and suggest that the fmθ uptraining protocol is an effective intervention program for cognitive aging. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.
Frenzel, J. F.
The increased use of on-chip cache memories has led researchers to investigate their performance in the presence of manufacturing defects. Several techniques for yield improvement are discussed and results are presented which indicate that set-associativity may be used to provide defect tolerance as well as improve the cache performance. Tradeoffs between several cache organizations and replacement strategies are investigated and it is shown that token-based replacement may be a suitable alternative to the widely-used LRU strategy.
Barch, Deanna M; Carter, Cameron S; Gold, James M; Johnson, Sheri L; Kring, Ann M; MacDonald, Angus W; Pizzagalli, Diego A; Ragland, J Daniel; Silverstein, Steven M; Strauss, Milton E
Motivational and hedonic impairments are core features of a variety of types of psychopathology. An important aspect of motivational function is reinforcement learning (RL), including implicit (i.e., outside of conscious awareness) and explicit (i.e., including explicit representations about potential reward associations) learning, as well as both positive reinforcement (learning about actions that lead to reward) and punishment (learning to avoid actions that lead to loss). Here we present data from paradigms designed to assess both positive and negative components of both implicit and explicit RL, examine performance on each of these tasks among individuals with schizophrenia, schizoaffective disorder, and bipolar disorder with psychosis, and examine their relative relationships to specific symptom domains transdiagnostically. None of the diagnostic groups differed significantly from controls on the implicit RL tasks in either bias toward a rewarded response or bias away from a punished response. However, on the explicit RL task, both the individuals with schizophrenia and schizoaffective disorder performed significantly worse than controls, but the individuals with bipolar did not. Worse performance on the explicit RL task, but not the implicit RL task, was related to worse motivation and pleasure symptoms across all diagnostic categories. Performance on explicit RL, but not implicit RL, was related to working memory, which accounted for some of the diagnostic group differences. However, working memory did not account for the relationship of explicit RL to motivation and pleasure symptoms. These findings suggest transdiagnostic relationships across the spectrum of psychotic disorders between motivation and pleasure impairments and explicit RL. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
Kreitz, Carina; Furley, Philip; Memmert, Daniel; Simons, Daniel J
Working memory and attention are closely related constructs. Models of working memory often incorporate an attention component, and some even equate working memory and attentional control. Although some attention-related processes, including inhibitory control of response conflict and interference resolution, are strongly associated with working memory, for other aspects of attention the link is less clear. We examined the association between working-memory performance and attentional breadth, the ability to spread attention spatially. If the link between attention and working memory is broader than inhibitory and interference resolution processes, then working-memory performance might also be associated with other attentional abilities, including attentional breadth. We tested 123 participants on a variety of working-memory and attentional-breadth measures, finding a strong correlation between performances on these two types of tasks. This finding demonstrates that the link between working memory and attention extends beyond inhibitory processes.
Cevik, V.; Altun, A.
This study aims to investigate how working memory (WM) performances and instructional strategy choices affect learners' complex cognitive task performance in online environments. Three different e-learning environments were designed based on Merrill's (2006a) model of instructional strategies. The lack of experimental research on his framework is…
Full Text Available A number of neuropsychological studies have revealed that memory problems are relatively common in patients with multiple sclerosis (MS. It may be useful to compare MS with conditions such as Huntington's disease (HD, which have been referred to as subcortical dementia. A characteristic of these conditions may be an impairment in implicit (unconscious memory, but not in explicit (conscious memory. The present study examined the functioning of explicit and implicit memory in MS. Results showed that implicit memory was not significantly impaired in the MS subjects, and that they were impaired on recall but not recognition. A correlation was found between implicit memory performance and disability status in MS patients. Findings also suggest the possibility of long-term priming of implicit memory in the control subjects. The implications of these results are discussed.
Sukkari, Dalal E.
The polar decomposition of a dense matrix is an important operation in linear algebra. It can be directly calculated through the singular value decomposition (SVD) or iteratively using the QR dynamically-weighted Halley algorithm (QDWH). The former is difficult to parallelize due to the preponderant number of memory-bound operations during the bidiagonal reduction. We investigate the latter scenario, which performs more floating-point operations but exposes at the same time more parallelism, and therefore, runs closer to the theoretical peak performance of the system, thanks to more compute-bound matrix operations. Profiling results show the performance scalability of QDWH for calculating the polar decomposition using around 9200 MPI processes on well and ill-conditioned matrices of 100K×100K problem size. We study then the performance impact of the QDWH-based polar decomposition as a pre-processing step toward calculating the SVD itself. The new distributed-memory implementation of the QDWH-SVD solver achieves up to five-fold speedup against current state-of-the-art vendor SVD implementations. © Springer International Publishing Switzerland 2016.
Prevatt, Frances; Welles, Theresa L.; Li, Huijun; Proctor, Briley
The impact of memory and anxiety on math performance was analyzed in a sample of 115 college undergraduates, all of whom had a diagnosed learning disability. The direct effects of memory and anxiety on math performance were first examined, followed by an examination of whether anxiety moderates the relationship between memory and math. Both memory…
Silva, Luis Humberto Rodríguez; Roehr-Brackin, Karen
This article draws on an approach that conceptualizes L2 learning difficulty in terms of implicit and explicit knowledge. In a study with first language Mexican Spanish university-level learners (n = 30), their teachers (n = 11), and applied linguistics experts (n = 3), we investigated the relationship between (a) these groups' difficulty…
Asifuzzaman, Kazi; Pavlovic, Milan; Radulovic, Milan; Zaragoza, David; Kwon, Ohseong; Ryoo, Kyung-Chang; Radojkovic, Petar
In high-performance computing (HPC), significant effort is invested in research and development of novel memory technologies. One of them is Spin Transfer Torque Magnetic Random Access Memory (STT-MRAM) --- byte-addressable, high-endurance non-volatile memory with slightly higher access time than DRAM. In this study, we conduct a preliminary assessment of HPC system performance impact with STT-MRAM main memory with recent industry estimations. Reliable timing parameters of STT-MRAM devices ar...
Wang, Hua; Nie, Feiping; Huang, Heng; Risacher, Shannon; Ding, Chris; Saykin, Andrew J.; Shen, Li
Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by progressive impairment of memory and other cognitive functions, which makes regression analysis a suitable model to study whether neuroimaging measures can help predict memory performance and track the progression of AD. Existing memory performance prediction methods via regression, however, do not take into account either the interconnected structures within imaging data or those among memory scores, which inevitably r...
Djomehri, M. Jahed; Rizk, Yehia M.
The presentation discusses recent studies on the performance of the two parallel versions of the aerodynamics CFD code, OVERFLOW_MPI and _MLP. Developed at NASA Ames, the serial version, OVERFLOW, is a multidimensional Navier-Stokes flow solver based on overset (Chimera) grid technology. The code has recently been parallelized in two ways. One is based on the explicit message-passing interface (MPI) across processors and uses the _MPI communication package. This approach is primarily suited for distributed memory systems and workstation clusters. The second, termed the multi-level parallel (MLP) method, is simple and uses shared memory for all communications. The _MLP code is suitable on distributed-shared memory systems. For both methods, the message passing takes place across the processors or processes at the advancement of each time step. This procedure is, in effect, the Chimera boundary conditions update, which is done in an explicit "Jacobi" style. In contrast, the update in the serial code is done in more of the "Gauss-Sidel" fashion. The programming efforts for the _MPI code is more complicated than for the _MLP code; the former requires modification of the outer and some inner shells of the serial code, whereas the latter focuses only on the outer shell of the code. The _MPI version offers a great deal of flexibility in distributing grid zones across a specified number of processors in order to achieve load balancing. The approach is capable of partitioning zones across multiple processors or sending each zone and/or cluster of several zones into a single processor. The message passing across the processors consists of Chimera boundary and/or an overlap of "halo" boundary points for each partitioned zone. The MLP version is a new coarse-grain parallel concept at the zonal and intra-zonal levels. A grouping strategy is used to distribute zones into several groups forming sub-processes which will run in parallel. The total volume of grid points in each
Full Text Available Performing two cognitively demanding tasks at the same time is known to decrease performance. The current study investigates the underlying executive functions of a dual-tasking situation involving the simultaneous performance of decision making under explicit risk and a working memory task. It is suggested that making a decision and performing a working memory task at the same time should particularly require monitoring - an executive control process supervising behavior and the state of processing on two tasks. To test the role of a supervisory/monitoring function in such a dual-tasking situation we investigated 122 participants with the Game of Dice Task plus 2-back task (GDT plus 2-back task. This dual task requires participants to make decisions under risk and to perform a 2-back working memory task at the same time. Furthermore, a task measuring a set of several executive functions gathered in the term concept formation (Modified Card Sorting Test, MCST and the newly developed Balanced Switching Task (BST, measuring monitoring in particular, were used. The results demonstrate that concept formation and monitoring are involved in the simultaneous performance of decision making under risk and a working memory task. In particular, the mediation analysis revealed that BST performance partially mediates the influence of MCST performance on the GDT plus 2-back task. These findings suggest that monitoring is one important subfunction for superior performance in a dual-tasking situation including decision making under risk and a working memory task.
Cheie, Lavinia; MacLeod, Colin; Miclea, Mircea; Visu-Petra, Laura
The preparatory attentional and memory processes theory (PAM) of prospective memory (PM) proposes that prospective remembering is influenced by the variation in the availability of WM resources. Consequently, PM should be impaired when WM resources are reduced either by direct WM manipulation or by individual differences associated with restricted WM performance. Our study tested this prediction in school-age children by examining the independent and interactive effects of three factors known to deplete availability of WM resources: increased processing demands of a concurrent arithmetic task, additional WM span requirements, and high trait anxiety. A sample of 10-year-old children (N = 128) performed a PM task, embedded in an ongoing arithmetic task, which progressively imposed greater WM processing demands. Half of these participants also concurrently carried out an embedded WM span task. The results supported the PAM hypothesis, showing that children's PM was compromised by the restriction of WM resources, whether this resulted from increasing the processing demands on the ongoing task, from imposing additional WM span requirements, or from high trait anxiety. However, these WM-depleting factors exerted additive effects rather than an interactive impact, suggesting that they might each deplete different aspects of WM resource availability necessary for prospective remembering. Overall findings imply that children's PM success is not only associated to their WM capacity but it mostly depends upon how many of those WM resources are available to be devoted to the PM requirement.
... it has to decide what is worth remembering. Memory is the process of storing and then remembering this information. There are different types of memory. Short-term memory stores information for a few ...
Manipulations that induce disfluency during encoding generally produce lower memory predictions for the disfluent condition than for the fluent condition. Similar to other manipulations of disfluency, generating lies takes longer and requires more mental effort than does telling the truth; hence, a manipulation of lie generation might produce patterns similar to other types of fluency for memory predictions. The current study systematically investigates the effect of a lie-generation manipulation on both actual and predicted memory performance. In a series of experiments, participants told the truth or generated plausible lies to general knowledge questions and made item-by-item predictions about their subsequent memory performance during encoding, followed by a free recall test. Participants consistently predicted their memory performance to be higher for truth than for lies (Experiments 1 through 4), despite their typically superior actual memory performance for lies than for the truth (Experiments 1 through 3), producing double dissociations between memory and metamemory. Moreover, lying led to longer response latencies than did telling the truth, showing that generating lies is in fact objectively more disfluent. An additional experiment compared memory predictions for truth and lie trials via a scenario about the lie-generation manipulation used in the present study, which revealed superior memory predictions of truth than of lies, providing proof for a priori beliefs about the effects of lying on predicted memory (Experiment 5). The effects of the current lie-generation manipulation on metamemory are discussed in light of experience-based and theory-based processes on making judgments of learning. Theoretical and practical implications of this experimental paradigm are also considered. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
de Quervain, Dominique J-F; Papassotiropoulos, Andreas
Experimental work in animals has shown that memory formation depends on a cascade of molecular events. Here we show that variability of human memory performance is related to variability in genes encoding proteins of this signaling cascade, including the NMDA and metabotrobic glutamate receptors, adenylyl cyclase, CAMKII, PKA, and PKC. The individual profile of genetic variability in these signaling molecules correlated significantly with episodic memory performance (P < 0.00001). Moreover, functional MRI during memory formation revealed that this genetic profile correlated with activations in memory-related brain regions, including the hippocampus and parahippocampal gyrus. The present study indicates that genetic variability in the human homologues of memory-related signaling molecules contributes to interindividual differences in human memory performance and memory-related brain activations.
Steenbergen, Bert; van der Kamp, John; Verneau, Marion; Jongbloed-Pereboom, Marjolein; Masters, Rich S W
Motor skills can be learned in an explicit or an implicit manner. Explicit learning places high demands on working memory capacity, but engagement of working memory is largely circumvented when skills are learned implicitly. We propose that individuals with impaired movement dynamics may benefit from implicit learning methods when acquiring sports-related motor skills. We discuss converging evidence that individuals with cerebral palsy and children born prematurely have compromised working memory capacity. This may in part explain the difficulties they encounter when learning motor and other skills. We also review tentative evidence that older people, whose movement dynamics deteriorate, can implicitly learn sports-related motor skills and that this results in more durable performance gains than explicit learning. Individuals with altered movement dynamics and compromised working memory can benefit from implicit motor learning. We conclude with an appeal for more extensive evaluation of the merits of implicit motor learning in individuals with impaired movement dynamics.
Psychological impact of unexpected explicit recall of events occurring during surgery performed under sedation, regional anaesthesia, and general anaesthesia: data from the Anesthesia Awareness Registry.
Kent, C D; Mashour, G A; Metzger, N A; Posner, K L; Domino, K B
Anaesthetic awareness is a recognized complication of general anaesthesia (GA) and is associated with post-traumatic stress disorder (PTSD). Although complete amnesia for intraprocedural events during sedation and regional anaesthesia (RA) may occur, explicit recall is expected by anaesthesia providers. Consequently, the possibility that there could be psychological consequences associated with unexpected explicit recall of events during sedation and RA has not been investigated. This study investigated the psychological sequelae of unexpected explicit recall of events during sedation/RA that was reported to the Anesthesia Awareness Registry. The Registry recruited subjects who self-identified as having had anaesthetic awareness. Inclusion criteria were a patient-reported awareness experience in 1990 or later and availability of medical records. The sensations experienced by the subjects during their procedure and the acute and persistent psychological sequelae attributed to this explicit recall were assessed for patients receiving sedation/RA and those receiving GA. Among the patients fulfilling the inclusion criteria, medical record review identified 27 sedation/RA and 50 GA cases. Most patients experienced distress (78% of sedation/RA vs 94% of GA). Approximately 40% of patients with sedation/RA had persistent psychological sequelae, similar to GA patients. Some sedation/RA patients reported an adverse impact on their job performance (15%), family relationships (11%), and friendships (11%), and 15% reported being diagnosed with PTSD. Patients who self-reported to the Registry unexpected explicit recall of events during sedation/RA experienced distress and persistent psychological sequelae comparable with those who had reported anaesthetic awareness during GA. Further study is warranted to determine if patients reporting distress with explicit recall after sedation/RA require psychiatric follow-up.
Glienke, Katharina; Piefke, Martina
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. Copyright © 2016
Altmeyer, Michael; Schweizer, Karl; Reiss, Siegbert; Ren, Xuezhu; Schreiner, Michael
Performance in working memory and short-term memory tasks was employed for predicting performance in a long-term memory task in order to find out about the underlying processes. The types of memory were represented by versions of the Posner Task, the Backward Counting Task and the Sternberg Task serving as measures of long-term memory, working…
Oertel-Knöchel, Viola; Reinke, Britta; Matura, Silke; Prvulovic, David; Linden, David E J; van de Ven, Vincent
In this study, we sought to examine the intrinsic functional organization of the episodic memory network during rest in bipolar disorder (BD). The previous work suggests that deficits in intrinsic functional connectivity may account for impaired memory performance. We hypothesized that regions involved in episodic memory processing would reveal aberrant functional connectivity in patients with bipolar disorder. We examined 21 patients with BD and 21 healthy matched controls who underwent functional magnetic resonance imaging (fMRI) during a resting condition. We did a seed-based functional connectivity analysis (SBA), using the regions of the episodic memory network that showed a significantly different activation pattern during task-related fMRI as seeds. The functional connectivity scores (FC) were further correlated with episodic memory task performance. Our results revealed decreased FC scores within frontal areas and between frontal and temporal/hippocampal/limbic regions in BD patients in comparison with controls. We observed higher FC in BD patients compared with controls between frontal and limbic regions. The decrease in fronto-frontal functional connectivity in BD patients showed a significant positive association with episodic memory performance. The association between task-independent dysfunctional frontal-limbic FC and episodic memory performance may be relevant for current pathophysiological models of the disease. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
Vineyard, Craig Michael [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Verzi, Stephen Joseph [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
As high performance computing architectures pursue more computational power there is a need for increased memory capacity and bandwidth as well. A multi-level memory (MLM) architecture addresses this need by combining multiple memory types with different characteristics as varying levels of the same architecture. How to efficiently utilize this memory infrastructure is an unknown challenge, and in this research we sought to investigate whether neural inspired approaches can meaningfully help with memory management. In particular we explored neurogenesis inspired re- source allocation, and were able to show a neural inspired mixed controller policy can beneficially impact how MLM architectures utilize memory.
Full Text Available The motivation of this research was to evaluate the main memory performance of a hybrid super computer such as the Convey HC-x, and ascertain how the controller performs in several access scenarios, vis-à-vis hand-coded memory prefetches. Such memory patterns are very useful in stencil computations. The theoretical bandwidth of the memory of the Convey is compared with the results of our measurements. The accurate study of the memory subsystem is particularly useful for users when they are developing their application-specific personality. Experiments were performed to measure the bandwidth between the coprocessor and the memory subsystem. The experiments aimed mainly at measuring the reading access speed of the memory from Application Engines (FPGAs. Different ways of accessing data were used in order to find the most efficient way to access memory. This way was proposed for future work in the Convey HC-x. When performing a series of accesses to memory, non-uniform latencies occur. The Memory Controller of the Convey HC-x in the coprocessor attempts to cover this latency. We measure memory efficiency as a ratio of the number of memory accesses and the number of execution cycles. The result of this measurement converges to one in most cases. In addition, we performed experiments with hand-coded memory accesses. The analysis of the experimental results shows how the memory subsystem and Memory Controllers work. From this work we conclude that the memory controllers do an excellent job, largely because (transparently to the user they seem to cache large amounts of data, and hence hand-coding is not needed in most situations.
Sozda, Christopher N; Muir, James J; Springer, Utaka S; Partovi, Diana; Cole, Michael A
Memory complaints are particularly salient among veterans who experience combat-related mild traumatic brain injuries and/or trauma exposure, and represent a primary barrier to successful societal reintegration and everyday functioning. Anecdotally within clinical practice, verbal learning and memory performance frequently appears differentially reduced versus visual learning and memory scores. We sought to empirically investigate the robustness of a verbal versus visual learning and memory discrepancy and to explore potential mechanisms for a verbal/visual performance split. Participants consisted of 103 veterans with reported history of mild traumatic brain injuries returning home from U.S. military Operations Enduring Freedom and Iraqi Freedom referred for outpatient neuropsychological evaluation. Findings indicate that visual learning and memory abilities were largely intact while verbal learning and memory performance was significantly reduced in comparison, residing at approximately 1.1 SD below the mean for verbal learning and approximately 1.4 SD below the mean for verbal memory. This difference was not observed in verbal versus visual fluency performance, nor was it associated with estimated premorbid verbal abilities or traumatic brain injury history. In our sample, symptoms of depression, but not posttraumatic stress disorder, were significantly associated with reduced composite verbal learning and memory performance. Verbal learning and memory performance may benefit from targeted treatment of depressive symptomatology. Also, because visual learning and memory functions may remain intact, these might be emphasized when applying neurocognitive rehabilitation interventions to compensate for observed verbal learning and memory difficulties.
Full Text Available The binge drinking (BD pattern of alcohol consumption is prevalent during adolescence, a period characterized by critical changes to the structural and functional development of brain areas related with memory and cognition. There is considerable evidence of the cognitive dysfunctions caused by the neurotoxic effects of BD in the not-yet-adult brain. Thus, the aim of the present study was to evaluate the effects of different blood alcohol concentrations (BAC on memory during late adolescence (18–19 years old in males and females with a history of BD. The sample consisted of 154 adolescents (67 males and 87 females that were classified as refrainers if they had never previously drunk alcoholic drinks and as binge drinkers if they had drunk six or more standard drink units in a row for men or five or more for women at a minimum frequency of three occasions in a month, throughout the previous 12 months. After intake of a high acute dose of alcohol by binge drinkers or a control refreshment by refrainers and binge drinkers, subjects were distributed into four groups for each gender according to their BAC: BAC0-R (0 g/L, in refrainers, BAC0-BD (0 g/L, in binge drinkers, BAC1 (0.3 – 0.5 g/L, in binge drinkers or BAC2 (0.54 – 1.1 g/L, in binge drinkers. The subjects’ immediate visual memory and working memory were then measured according to the Wechsler Memory Scale (WMS-III. The BAC1 group showed lower scores of immediate visual memory but not of working memory, while lower performance in both memories were found in the BAC2 group. Therefore, the brain of binge drinkers with moderate BAC could be employing compensatory mechanisms from additional brain areas to perform a working memory task adequately, but these resources would be undermined when BAC is higher (>0.5 g/L. No gender differences were found in BAC-related lower performance in immediate visual memory and working memory. In conclusion, immediate visual memory is more sensitive than
After decades of relentless progress, the silicon CMOS industry is approaching a stall in device performance for both logic and memory devices due to fundamental scaling limitations. In order to reinforce the accelerating pace, novel materials with unique properties are being proposed on an urgent basis. This list includes one dimensional nanotubes, quasi one dimensional nanowires, two dimensional atomistically thin layered materials like graphene, hexagonal boron nitride and the more recently the rich family of transition metal di-chalcogenides comprising of MoS2, WSe2, WS2 and many more for logic applications and organic and inorganic ferroelectrics, phase change materials and magnetic materials for memory applications. Only time will tell who will win, but exploring these novel materials allow us to revisit the fundamentals and strengthen our understanding which will ultimately be beneficial for high performance device design. While there has been growing interest in two-dimensional (2D) crystals other than graphene, evaluating their potential usefulness for electronic applications is still in its infancies due to the lack of a complete picture of their performance potential. The fact that the 2-D layered semiconducting di-chalcogenides need to be connected to the "outside" world in order to capitalize on their ultimate potential immediately emphasizes the importance of a thorough understanding of the contacts. This thesis demonstrate that through a proper understanding and design of source/drain contacts and the right choice of number of MoS2 layers the excellent intrinsic properties of this 2D material can be harvested. A comprehensive experimental study on the dependence of carrier mobility on the layer thickness of back gated multilayer MoS 2 field effect transistors is also provided. A resistor network model that comprises of Thomas-Fermi charge screening and interlayer coupling is used to explain the non-monotonic trend in the extracted field effect
McAlister, Courtney; Schmitter-Edgecombe, Maureen
This study examined content and temporal order memory for subject-performed activities in an incidental learning condition in cognitively healthy individuals with Parkinson's disease (PD) (N = 20) and controls (N = 20). Participant's free recall of activities provided a measure of content memory. Temporal order memory was assessed with a reconstruction task of activities. Self- and informant-reports of everyday memory were used to examine the relationship between everyday memory, and content and temporal order memory. Individuals with PD recalled fewer activities although recognition memory was intact. Temporal order memory was also impaired for individuals with PD. For the PD group, both self- and informant-reports of changes in current memory abilities were strongly associated with temporal order memory but not content memory for activities. These findings suggest that there is a strong link between everyday memory abilities and temporal order memory for activities, and support the need for additional study of temporal order memory abilities in PD. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: email@example.com.
Sumner, Jennifer A; Mineka, Susan; McAdams, Dan P
Reduced autobiographical memory specificity (AMS) is an important cognitive marker in depression that is typically measured with the Autobiographical Memory Test (AMT; Williams & Broadbent, 1986). The AMT is widely used, but the over-reliance on a single methodology for assessing AMS is a limitation in the field. The current study investigated memory narratives as an alternative measure of AMS in an undergraduate student sample selected for being high or low on a measure of depressive symptoms (N=55). We employed a multi-method design to compare narrative- and AMT-based measures of AMS. Participants generated personally significant self-defining memory narratives, and also completed two versions of the AMT (with and without instructions to retrieve specific memories). Greater AMS in self-defining memory narratives correlated with greater AMS in performance on both versions of the AMT in the full sample, and the patterns of relationships between the different AMS measures were generally similar in low and high dysphoric participants. Furthermore, AMS in self-defining memory narratives was prospectively associated with depressive symptom levels. Specifically, greater AMS in self-defining memory narratives predicted fewer depressive symptoms at a 10-week follow-up over and above baseline symptom levels. Implications for future research and clinical applications are discussed.
Mürner-Lavanchy I; Ritter B C; Spencer-Smith M M; Perrig W J; Schroth G.; Steinlin M; Everts R
Working memory is crucial for meeting the challenges of daily life and performing academic tasks such as reading or arithmetic. Very preterm born children are at risk of low working memory capacity. The aim of this study was to examine the visuospatial working memory network of school aged preterm children and to determine the effect of age and performance on the neural working memory network. Working memory was assessed in 41 very preterm born children and 36 term born controls (aged 7 12 ye...
Pansky, Ainat; Goldsmith, Morris
In two experiments, we examined whether relative retrieval fluency (the relative ease or difficulty of answering questions from memory) would be translated, via metacognitive monitoring and control processes, into an overt effect on the controlled behavior-that is, the decision whether to answer a question or abstain. Before answering a target set of multiple-choice general-knowledge questions (intermediate-difficulty questions in Exp. 1, deceptive questions in Exp. 2), the participants first answered either a set of difficult questions or a set of easy questions. For each question, they provided a forced-report answer, followed by a subjective assessment of the likelihood that their answer was correct (confidence) and by a free-report control decision-whether or not to report the answer for a potential monetary bonus (or penalty). The participants' ability to answer the target questions (forced-report proportion correct) was unaffected by the initial question difficulty. However, a predicted metacognitive contrast effect was observed: When the target questions were preceded by a set of difficult rather than easy questions, the participants were more confident in their answers to the target questions, and hence were more likely to report them, thus increasing the quantity of freely reported correct information. The option of free report was more beneficial after initial question difficulty than after initial question ease, in terms of both the gain in accuracy (Exp. 2) and a smaller cost in quantity (Exps. 1 and 2). These results demonstrate that changes in subjective experience can influence metacognitive monitoring and control, thereby affecting free-report memory performance independently of forced-report performance.
Sepeta, Leigh N.; Casaletto, Kaitlin Blackstone; Terwilliger, Virginia; Facella-Ervolini, Joy; Sady, Maegan; Mayo, Jessica; Gaillard, William D.; Berl, Madison M.
Objective Learning and memory are essential for academic success and everyday functioning, but the pattern of memory skills and its relationship to executive functioning in children with focal epilepsy is not fully delineated. We address a gap in the literature by examining the relationship between memory and executive functioning in a pediatric focal epilepsy population. Methods Seventy children with focal epilepsy and 70 typically developing children matched on age, intellectual functioning, and gender underwent neuropsychological assessment, including measures of intelligence (WASI/DAS), as well as visual (CMS Dot Locations) and verbal episodic memory (WRAML Story Memory and CVLT-C). Executive functioning was measured directly (WISC-IV Digit Span Backward; CELF-IV Recalling Sentences) and by parent report (Behavior Rating Inventory of Executive Function (BRIEF)). Results Children with focal epilepsy had lower delayed free recall scores than controls across visual and verbal memory tasks (p = 0.02; partial η2 = .12). In contrast, recognition memory performance was similar for patients and controls (p = 0.36; partial η2 = .03). Children with focal epilepsy demonstrated difficulties in working memory (p = 0.02; partial η2 = .08) and planning/organization (p = 0.02) compared to controls. Working memory predicted 9–19% of the variance in delayed free recall for verbal and visual memory; organization predicted 9–10% of the variance in verbal memory. Patients with both left and right focal epilepsy demonstrated more difficulty on verbal versus visual tasks (p = 0.002). Memory performance did not differ by location of seizure foci (temporal vs. extra-temporal, frontal vs. extra-frontal). Significance Children with focal epilepsy demonstrated memory ability within age-level expectations, but delayed free recall was inefficient compared to typically developing controls. Memory difficulties were not related to general cognitive impairment or seizure localization
Stanley, Matthew L.; Simpson, Sean L.; Dagenbach, Dale; Lyday, Robert G.; Burdette, Jonathan H.; Laurienti, Paul J.
Working memory is a complex psychological construct referring to the temporary storage and active processing of information. We used functional connectivity brain network metrics quantifying local and global efficiency of information transfer for predicting individual variability in working memory performance on an n-back task in both young (n = 14) and older (n = 15) adults. Individual differences in both local and global efficiency during the working memory task were significant predictors of working memory performance in addition to age (and an interaction between age and global efficiency). Decreases in local efficiency during the working memory task were associated with better working memory performance in both age cohorts. In contrast, increases in global efficiency were associated with much better working performance for young participants; however, increases in global efficiency were associated with a slight decrease in working memory performance for older participants. Individual differences in local and global efficiency during resting-state sessions were not significant predictors of working memory performance. Significant group whole-brain functional network decreases in local efficiency also were observed during the working memory task compared to rest, whereas no significant differences were observed in network global efficiency. These results are discussed in relation to recently developed models of age-related differences in working memory. PMID:25875001
Deanna Baldock; Miller, Justin B.; Leger, Gabriel C.; Sarah Jane Banks
Background: Patients with frontotemporal dementia (FTD) typically have initial deficits in language or changes in personality, while the defining characteristic of Alzheimer's disease (AD) is memory impairment. Neuropsychological findings in the two diseases tend to differ, but can be confounded by verbal impairment in FTD impacting performance on memory tests in these patients. Methods: Twenty-seven patients with FTD and 102 patients with AD underwent a neuropsychological assessment before d...
Schumacher, Jorn; The ATLAS collaboration; Borga, Andrea; Boterenbrood, Hendrik; Chen, Hucheng; Chen, Kai; Drake, Gary; Francis, David; Gorini, Benedetto; Lanni, Francesco; Lehmann Miotto, Giovanna; Levinson, Lorne; Narevicius, Julia; Roich, Alexander; Ryu, Soo; Schreuder, Frans Philip; Vandelli, Wainer; Zhang, Jinlong; Vermeulen, Jos
Experiments in high-energy physics (HEP) and related fields often impose constraints and challenges on data acquisition systems. As a result, these systems are implemented as unique mixtures of custom and commercial-off-the-shelf electronics (COTS), involving and connecting radiation-hard devices, large high-performance networks, and computing farms. FELIX, the Frontend Link Exchange, is a new PC-based general purpose data routing device for the data-acquisition system of the ATLAS experiment at CERN. Performance is a very crucial point for devices like FELIX, which have to be capable of processing tens of gigabyte of data per second. Thus it is important to understand the performance limitations for typical workloads on modern hardware. We present an analysis of a packet processing algorithm that is used in FELIX, and show how the PC system's memory architecture plays a key factor in the overall data throughput achieved by the application. Finally, we present optimizations that increase the processing throug...
Laier, Christian; Schulte, Frank P; Brand, Matthias
Some individuals report problems during and after Internet sex engagement, such as missing sleep and forgetting appointments, which are associated with negative life consequences. One mechanism potentially leading to these kinds of problems is that sexual arousal during Internet sex might interfere with working memory (WM) capacity, resulting in a neglect of relevant environmental information and therefore disadvantageous decision making. In this study, 28 healthy individuals performed 4 experimental manipulations of a pictorial 4-back WM task with neutral, negative, positive, or pornographic stimuli. Participants also rated 100 pornographic pictures with respect to sexual arousal and indicated masturbation urges previous to and following pornographic picture presentation. Results revealed worse WM performance in the pornographic picture condition of the 4-back task compared with the three remaining picture conditions. Furthermore, hierarchical regression analysis indicated an explanation of variance of the sensitivity in the pornographic picture condition by the subjective rating of the pornographic pictures as well as by a moderation effect of masturbation urges. Results contribute to the view that indicators of sexual arousal due to pornographic picture processing interfere with WM performance. Findings are discussed with respect to Internet sex addiction because WM interference by addiction-related cues is well known from substance dependencies.
Zanto, Theodore P; Chadick, James Z; Gazzaley, Adam
Alpha band (8-12 Hz) phase dynamics in the visual cortex are thought to reflect fluctuations in cortical excitability that influences perceptual processing. As such, visual stimuli are better detected when their onset is concurrent with specific phases of the alpha cycle. However, it is unclear whether alpha phase differentially influences cognitive performance at specific times relative to stimulus onset (i.e., is the influence of phase maximal before, at, or after stimulus onset?). To address this, participants performed a delayed-recognition, working memory (WM) task for visual motion direction during two separate visits. The first visit utilized functional magnetic resonance (fMRI) imaging to identify neural regions associated with task performance. Replicating previous studies, fMRI data showed engagement of visual cortical area V5, as well as a prefrontal cortical region, the inferior frontal junction (IFJ). During the second visit, transcranial magnetic stimulation (TMS) was applied separately to both the right IFJ and right V5 (with the vertex as a control region) while electroencephalography (EEG) was simultaneously recorded. During each trial, a single pulse of TMS (spTMS) was applied at one of six time points (-200, -100, -50, 0, 80, 160 ms) relative to the encoded stimulus onset. Results demonstrated a relationship between the phase of the posterior alpha signal prior to stimulus encoding and subsequent response times to the memory probe two seconds later. Specifically, spTMS to V5, and not the IFJ or vertex, yielded faster response times, indicating improved WM performance, when delivered during the peak, compared to the trough, of the alpha cycle, but only when spTMS was applied 100 ms prior to stimulus onset. These faster responses to the probe correlated with decreased early event related potential (ERP) amplitudes (i.e., P1) to the probe stimuli. Moreover, participants that were least affected by spTMS exhibited greater functional connectivity
Full Text Available In-memory database systems are among the most recent and most promising Big Data technologies, being developed and released either as brand new distributed systems or as extensions of old monolith (centralized database systems. As name suggests, in-memory systems cache all the data into special memory structures. Many are part of the NewSQL strand and target to bridge the gap between OLTP and OLAP into so-called Hybrid Transactional Analytical Systems (HTAP. This paper aims to test the performance of using such type of systems for TPCH analytical workloads. Performance is analyzed in terms of data loading, memory footprint and execution time of the TPCH query set for three in-memory data systems: Oracle, SQL Server and MemSQL. Tests are subsequently deployed on classical on-disk architectures and results compared to in-memory solutions. As in-memory is an enterprise edition feature, associated costs are also considered.
Franz, A., LLNL
The numerical simulation of chemically reacting flows is a topic, that has attracted a great deal of current research At the heart of numerical reactive flow simulations are large sets of coupled, nonlinear Partial Differential Equations (PDES). Due to the stiffness that is usually present, explicit time differencing schemes are not used despite their inherent simplicity and efficiency on parallel and vector machines, since these schemes require prohibitively small numerical stepsizes. Implicit time differencing schemes, although possessing good stability characteristics, introduce a great deal of computational overhead necessary to solve the simultaneous algebraic system at each timestep. This thesis examines an algorithm based on a preconditioned time differencing scheme. The algorithm is explicit and permits a large stable time step. An investigation of the algorithm`s accuracy, stability and performance on a parallel architecture is presented
Saliasi, Emi; Geerligs, Linda; Lorist, Monicque M.; Maurits, Natasha M.
While some elderly show deteriorations in cognitive performance, others achieve performance levels comparable to young adults. To examine whether age-related changes in brain activity varied with working memory performance efficiency, we recorded electroencephalography (EEG) from young and older
Full Text Available Working memory is crucial for meeting the challenges of daily life and performing academic tasks, such as reading or arithmetic. Very preterm born children are at risk of low working memory capacity. The aim of this study was to examine the visuospatial working memory network of school-aged preterm children and to determine the effect of age and performance on the neural working memory network. Working memory was assessed in 41 very preterm born children and 36 term born controls (aged 7–12 years using functional magnetic resonance imaging (fMRI and neuropsychological assessment. While preterm children and controls showed equal working memory performance, preterm children showed less involvement of the right middle frontal gyrus, but higher fMRI activation in superior frontal regions than controls. The younger and low-performing preterm children presented an atypical working memory network whereas the older high-performing preterm children recruited a working memory network similar to the controls. Results suggest that younger and low-performing preterm children show signs of less neural efficiency in frontal brain areas. With increasing age and performance, compensational mechanisms seem to occur, so that in preterm children, the typical visuospatial working memory network is established by the age of 12 years.
Mürner-Lavanchy, I; Ritter, B C; Spencer-Smith, M M; Perrig, W J; Schroth, G; Steinlin, M; Everts, R
Working memory is crucial for meeting the challenges of daily life and performing academic tasks, such as reading or arithmetic. Very preterm born children are at risk of low working memory capacity. The aim of this study was to examine the visuospatial working memory network of school-aged preterm children and to determine the effect of age and performance on the neural working memory network. Working memory was assessed in 41 very preterm born children and 36 term born controls (aged 7-12 years) using functional magnetic resonance imaging (fMRI) and neuropsychological assessment. While preterm children and controls showed equal working memory performance, preterm children showed less involvement of the right middle frontal gyrus, but higher fMRI activation in superior frontal regions than controls. The younger and low-performing preterm children presented an atypical working memory network whereas the older high-performing preterm children recruited a working memory network similar to the controls. Results suggest that younger and low-performing preterm children show signs of less neural efficiency in frontal brain areas. With increasing age and performance, compensational mechanisms seem to occur, so that in preterm children, the typical visuospatial working memory network is established by the age of 12 years. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.
de Quervain, Dominique J.-F.; Papassotiropoulos, Andreas
Experimental work in animals has shown that memory formation depends on a cascade of molecular events. Here we show that variability of human memory performance is related to variability in genes encoding proteins of this signaling cascade, including the NMDA and metabotrobic glutamate receptors, adenylyl cyclase, CAMKII, PKA, and PKC. The individual profile of genetic variability in these signaling molecules correlated significantly with episodic memory performance (P < 0.00001). Moreover, f...
Piras, F; Caltagirone, C; Spalletta, G
Research on the neural basis of working memory (WM) has generally focused on cortical regions, specifically frontal and parietal areas. Comparatively, evidence of a possible involvement of deep gray matter structures, that are parts of cortico-cortical circuits linking anterior and posterior cortical areas, is far less clear. The goal of the present study is to test the hypothesis that individual structural variations within deep gray matter structures may affect the cortical networks involved in WM. To this aim, a large sample (n=181) of healthy subjects underwent a high-resolution structural magnetic resonance imaging (MRI) and a diffusion tensor imaging (DTI) scan protocol. Data of micro- (mean diffusivity, MD) and macro- (volume) structural variations of six bilateral deep gray matter structures (thalamus, caudate nucleus, putamen, hippocampus, amygdala and pallidum) and lateral ventriculi volume were analyzed in association with score in a WM (the so-called n-back task) and other neuropsychological tasks. Results showed that increased MD of bilateral thalami was the only structural parameter that significantly correlated with reduced WM performance. In particular, a voxel-by-voxel analysis revealed that the greater percentage of voxels showing significant anticorrelation between WM score and MD values were localized in those thalamic nuclei projecting to prefrontal and posterior parietal cortices. Results highlight the specific involvement of thalamus microstructure, not volume, in modulating WM performance, possibly by regulating the connections among cortical areas that are recruited during WM tasks. Copyright © 2010 IBRO. Published by Elsevier Ltd. All rights reserved.
Engel de Abreu, Pascale M J; Puglisi, Marina L; Cruz-Santos, Anabela; Befi-Lopes, Debora M; Martin, Romain
This cross-cultural study investigates the impact of background experience on four verbal and visuo-spatial working memory (WM) tasks. A total of 84 children from low-income families were recruited from the following groups: (1) Portuguese immigrant children from Luxembourg impoverished in terms of language experience; (2) Brazilian children deprived in terms of scholastic background; (3) Portuguese children from Portugal with no disadvantage in either scholastic or language background. Children were matched on age, gender, fluid intelligence, and socioeconomic status and completed four simple and complex span tasks of WM and a vocabulary measure. Results indicate that, despite large differences in their backgrounds and language abilities, the groups exhibited comparable performance on the visuo-spatial tasks dot matrix and odd-one-out and on the verbal simple span task digit recall. Group differences emerged on the verbal complex span task counting recall with children from Luxembourg and Portugal outperforming children from disadvantaged schools in Brazil. The study suggests that whereas contributions of prior knowledge to digit span, dot matrix, and odd-one-out are likely to be minimal, background experience can affect performance on counting recall. Implications for testing WM capacity in children growing up in poverty are discussed.
Geldorp, B. van; Bergmann, H.C.; Robertson, J.; Wester, A.J.; Kessels, R.P.C.
Both neuroimaging work and studies investigating amnesic patients have shown involvement of the medial temporal lobe during working memory tasks, especially when multiple items or features have to be associated. However, so far no study has examined the relationship between working memory and
Geldorp, B. van; Bergmann, H.; Robertson, J.; Wester, A.J.; Kessels, R.P.C.
Both neuroimaging work and studies investigating amnesic patients have shown involvement of the medial temporal lobe during working memory tasks, especially when multiple items or features have to be associated. However, so far no study has examined the relationship between working memory and
Full Text Available Background: Patients with frontotemporal dementia (FTD typically have initial deficits in language or changes in personality, while the defining characteristic of Alzheimer's disease (AD is memory impairment. Neuropsychological findings in the two diseases tend to differ, but can be confounded by verbal impairment in FTD impacting performance on memory tests in these patients. Methods: Twenty-seven patients with FTD and 102 patients with AD underwent a neuropsychological assessment before diagnosis. By utilizing analogous versions of a verbal and nonverbal memory test, we demonstrated differences in these two modalities between AD and FTD. Discussion: Better differentiation between AD and FTD is found in a nonverbal memory test, possibly because it eliminates the confounding variable of language deficits found in patients with FTD. These results highlight the importance of nonverbal learning tests with multiple learning trials in diagnostic testing.
Pillai, Roshni; Yathiraj, Asha
The study evaluated whether there exists a difference/relation in the way four different memory skills (memory score, sequencing score, memory span, & sequencing span) are processed through the auditory modality, visual modality and combined modalities. Four memory skills were evaluated on 30 typically developing children aged 7 years and 8 years across three modality conditions (auditory, visual, & auditory-visual). Analogous auditory and visual stimuli were presented to evaluate the three modality conditions across the two age groups. The children obtained significantly higher memory scores through the auditory modality compared to the visual modality. Likewise, their memory scores were significantly higher through the auditory-visual modality condition than through the visual modality. However, no effect of modality was observed on the sequencing scores as well as for the memory and the sequencing span. A good agreement was seen between the different modality conditions that were studied (auditory, visual, & auditory-visual) for the different memory skills measures (memory scores, sequencing scores, memory span, & sequencing span). A relatively lower agreement was noted only between the auditory and visual modalities as well as between the visual and auditory-visual modality conditions for the memory scores, measured using Bland-Altman plots. The study highlights the efficacy of using analogous stimuli to assess the auditory, visual as well as combined modalities. The study supports the view that the performance of children on different memory skills was better through the auditory modality compared to the visual modality. Copyright © 2017 Elsevier B.V. All rights reserved.
Alavash, Mohsen; Doebler, Philipp; Holling, Heinz; Thiel, Christiane M; Gießing, Carsten
Is there one optimal topology of functional brain networks at rest from which our cognitive performance would profit? Previous studies suggest that functional integration of resting state brain networks is an important biomarker for cognitive performance. However, it is still unknown whether higher network integration is an unspecific predictor for good cognitive performance or, alternatively, whether specific network organization during rest predicts only specific cognitive abilities. Here, we investigated the relationship between network integration at rest and cognitive performance using two tasks that measured different aspects of working memory; one task assessed visual-spatial and the other numerical working memory. Network clustering, modularity and efficiency were computed to capture network integration on different levels of network organization, and to statistically compare their correlations with the performance in each working memory test. The results revealed that each working memory aspect profits from a different resting state topology, and the tests showed significantly different correlations with each of the measures of network integration. While higher global network integration and modularity predicted significantly better performance in visual-spatial working memory, both measures showed no significant correlation with numerical working memory performance. In contrast, numerical working memory was superior in subjects with highly clustered brain networks, predominantly in the intraparietal sulcus, a core brain region of the working memory network. Our findings suggest that a specific balance between local and global functional integration of resting state brain networks facilitates special aspects of cognitive performance. In the context of working memory, while visual-spatial performance is facilitated by globally integrated functional resting state brain networks, numerical working memory profits from increased capacities for local processing
Bisby, James A; Brewin, Chris R; Leitz, Julie R; Valerie Curran, H
Post-traumatic stress disorder is characterised by repeated intrusive imagery of the traumatic event. Despite alcohol's impairing effect on memory and frequent involvement in real-life trauma, virtually nothing is known of the interaction between alcohol and trauma memory. We aimed to investigate the acute alcohol effects on spontaneous memories following a trauma film as well as explicit memory for the film. Utilising an independent-group double-blind design, 48 healthy volunteers were randomly allocated to receive alcohol of 0.4 or 0.8 g/kg or a matched placebo drink. A stressful film was viewed post-drink. Skin conductance was monitored throughout and mood and dissociative symptoms were indexed. Volunteers recorded their spontaneous memories of the film daily in an online diary over the following week. Their explicit memory for both gist and details of the film was tested on day 7. Intriguingly, an inverted 'U' alcohol dose-response was observed on intrusive memories with a low dose of alcohol increasing memory intrusions while a high dose decreased intrusions. In contrast, explicit memory performance after 7 days showed a linear dose-response effect of alcohol with both recall and recognition decreasing as dose increased. These findings highlight a striking differential pattern of alcohol's effects on spontaneous memories as compared with explicit memories. Alcohol's effect on spontaneous memories may reflect a dose-dependent impairment of two separate memory systems integral to the processing of different aspects of a traumatic event.
This Oracle Press guide shows, step-by-step, how to optimize database performance and cut transaction processing time using Oracle Database 12c Release 2 In-Memory. Oracle Database 12c Release 2 In-Memory: Tips and Techniques for Maximum Performance features hands-on instructions, best practices, and expert tips from an Oracle enterprise architect. You will learn how to deploy the software, use In-Memory Advisor, build queries, and interoperate with Oracle RAC and Multitenant. A complete chapter of case studies illustrates real-world applications. • Configure Oracle Database 12c and construct In-Memory enabled databases • Edit and control In-Memory options from the graphical interface • Implement In-Memory with Oracle Real Application Clusters • Use the In-Memory Advisor to determine what objects to keep In-Memory • Optimize In-Memory queries using groups, expressions, and aggregations • Maximize performance using Oracle Exadata Database Machine and In-Memory option • Use Swingbench to create d...
Liebowitz, Matt; Spies, Rynardt
Covering the latest VMware vSphere software, an essential book aimed at solving vSphere performance problems before they happen VMware vSphere is the industry's most widely deployed virtualization solution. However, if you improperly deploy vSphere, performance problems occur. Aimed at VMware administrators and engineers and written by a team of VMware experts, this resource provides guidance on common CPU, memory, storage, and network-related problems. Plus, step-by-step instructions walk you through techniques for solving problems and shed light on possible causes behind the problems. Divu
Nissim, Nicole R.; O’Shea, Andrew M.; Bryant, Vaughn; Porges, Eric C.; Cohen, Ronald; Woods, Adam J.
Working memory is an executive memory process that allows transitional information to be held and manipulated temporarily in memory stores before being forgotten or encoded into long-term memory. Working memory is necessary for everyday decision-making and problem solving, making it a fundamental process in the daily lives of older adults. Working memory relies heavily on frontal lobe structures and is known to decline with age. The current study aimed to determine the neural correlates of decreased working memory performance in the frontal lobes by comparing cortical thickness and cortical surface area from two demographically matched groups of healthy older adults, free from cognitive impairment, with high versus low N-Back working memory performance (N = 56; average age = 70.29 ± 10.64). High-resolution structural T1-weighted images (1 mm isotropic voxels) were obtained on a 3T Philips MRI scanner. When compared to high performers, low performers exhibited significantly decreased cortical surface area in three frontal lobe regions lateralized to the right hemisphere: medial orbital frontal gyrus, inferior frontal gyrus, and superior frontal gyrus (FDR p working memory function. PMID:28101053
McDougall, Graham Joseph; Pituch, Keenan A; Stanton, Marietta P; Chang, Wanchen
After age 65, the incidence of episodic memory decline in males is greater than in females. We explored the influence of anxiety and depression on objective and subjective memory performance in a diverse sample of community-residing older adults. The study was a secondary analysis of data on three samples of adults from two states, Ohio and Texas: a community sample (n = 177); a retirement community sample (n = 97); and the SeniorWISE Study (n = 265). The sample of 529 adults was 74% female, the average age was 76.58 years (range = 59-100 years), and educational attainment was 13.12 years (±3.68); 68% were Caucasian, and 17% had depressive symptoms. We found no memory performance differences by gender. Males and females were similarly classified into the four memory performance groups, with almost half of each gender in the poor memory category. Even though males had greater years of education, they used fewer compensatory memory strategies. The observed gender differences in memory were subjective evaluations, specifically metamemory. Age was not a significant predictor of cognition or memory performance, nor did males have greater memory impairment than females.
Sünram-Lea, Sandra I; Foster, Jonathan K; Durlach, Paula; Perez, Catalina
Memory for a list of 20 words can be enhanced by preceding learning by consumption of 25 g of glucose, compared with consumption of an equally sweet aspartame solution (Psychopharmacology 137 (1998) 259; Psychopharmacology 157 (2001) 46). However, using this anterograde administration procedure, it is impossible to separate whether glucose affects encoding, consolidation, or retrieval. The present placebo-controlled, double-blind study investigated the effect of anterograde and retrograde administration on memory performance in healthy young participants. In order to evaluate whether post-acquisition administration of glucose can improve memory performance and to compare possible differences in the size of the effect, participants were administered 25 g of glucose immediately before or immediately after presentation of a word list. Moreover, in order to investigate whether the effect of glucose administration on memory performance is time-dependent, a third group received 25 g of glucose 15 min before learning the word list. Word- list recall was tested 30 min and 24 h after word list presentation. Measures of spatial memory performance and working memory were also evaluated. The results of this study showed that both pre- and post-acquisition oral glucose administration (25 g) can improve memory performance. However, as the time interval between anterograde glucose administration and memory encoding increased, the glucose memory facilitation effect decreased. This study provides evidence that glucose enhances memory performance in healthy young people even when it is given after learning has taken place, and that this effect is observed at least up to 24 h after glucose administration. Moreover, it provides evidence that the effect of glucose on memory performance may be time-dependent, as the enhancement of retention was decreased when the administration-learning interval was increased. Copyright 2002 Elsevier Science B.V.
Zanto, Theodore P; Gazzaley, Adam
...., top-down modulation). Such selective, goal-directed modulation of activity may be intimately related to memory, such that the focus of attention biases the likelihood of successfully maintaining relevant information...
Best, T; Bryan, J; Burns, N
To investigate the effects of glucose, or a combination of saccharides, or a placebo on the memory performance of middle-aged adults. A double-blind, placebo controlled design was used. A population-based sample of 45 men and women (aged 40-63 years) completed a series of memory tasks following administration of a single dose of either glucose, a combination of saccharides or placebo. Memory tasks included immediate and delayed recall, recognition, short-term memory, working memory, and a test of general cognitive ability. There were no statistically significant effects of treatments on any of the outcome measures. The pattern of means in the combination of saccharides group suggests potential enhancement effects of memory performance in middle-aged adults that deserves further investigation.
Köpke, Barbara; Nespoulous, Jean-Luc
International audience; Simultaneous interpreting is generally assumed to be particularly demanding with respect to cognitive resources like attention and working memory, which are thought to gradually increase with professional practice. Experimental data to corroborate such an assumption is still sparse, however. Here we report an in-depth investigation of working memory capacity among 21 professional interpreters (experts), 18 second-year interpreting students (novices) and two control gro...
Marquez de la Plata, C.; Lacritz, L.H.; Mitschke, R.; Ness, P; Agostini, M.; Diaz-Arrastia, R.; Cullum, C M
There is relatively little research pertaining to neuropsychological assessment of Spanish-speaking individuals with intractable temporal lobe epilepsy (TLE). The current study examined verbal and visual memory performances in 38 primarily Spanish-speaking patients with TLE (Right = 15, Left = 23) of similar epilepsy duration to determine if lateralizing differences can be found using verbal and nonverbal memory tests. On a test specifically designed to assess auditory learning and memory amo...
Full Text Available Brain-derived neurotrophic factor (BDNF is involved in numerous cognitive functions including learning and memory. BDNF plays an important role in synaptic plasticity in humans and rats with BDNF shown to be essential for the formation of long-term memories. We previously identified a significant association between the BDNF Val66Met polymorphism (rs6265 and long-term visual memory (p-value = 0.003 in a small cohort (n = 181 comprised of healthy individuals who had been phenotyped for various aspects of memory function. In this study, we have extended the cohort to 597 individuals and examined multiple genetic variants across both the BDNF and BDNF-AS genes for association with visual memory performance as assessed by the Wechsler Memory Scale—Fourth Edition subtests Visual Reproduction I and II (VR I and II. VR I assesses immediate visual memory, whereas VR II assesses long-term visual memory. Genetic association analyses were performed for 34 single nucleotide polymorphisms genotyped on Illumina OmniExpress BeadChip arrays with the immediate and long-term visual memory phenotypes. While none of the BDNF and BDNF-AS variants were shown to be significant for immediate visual memory, we found 10 variants (including the Val66Met polymorphism (p-value = 0.006 that were nominally associated, and three variants (two variants in BDNF and one variant in the BDNF-AS locus that were significantly associated with long-term visual memory. Our data therefore suggests a potential role for BDNF, and its anti-sense transcript BDNF-AS, in long-term visual memory performance.
Avgan, Nesli; Sutherland, Heidi G; Spriggens, Lauren K; Yu, Chieh; Ibrahim, Omar; Bellis, Claire; Haupt, Larisa M; Shum, David H K; Griffiths, Lyn R
Brain-derived neurotrophic factor (BDNF) is involved in numerous cognitive functions including learning and memory. BDNF plays an important role in synaptic plasticity in humans and rats with BDNF shown to be essential for the formation of long-term memories. We previously identified a significant association between the BDNF Val66Met polymorphism (rs6265) and long-term visual memory (p-value = 0.003) in a small cohort (n = 181) comprised of healthy individuals who had been phenotyped for various aspects of memory function. In this study, we have extended the cohort to 597 individuals and examined multiple genetic variants across both the BDNF and BDNF-AS genes for association with visual memory performance as assessed by the Wechsler Memory Scale-Fourth Edition subtests Visual Reproduction I and II (VR I and II). VR I assesses immediate visual memory, whereas VR II assesses long-term visual memory. Genetic association analyses were performed for 34 single nucleotide polymorphisms genotyped on Illumina OmniExpress BeadChip arrays with the immediate and long-term visual memory phenotypes. While none of the BDNF and BDNF-AS variants were shown to be significant for immediate visual memory, we found 10 variants (including the Val66Met polymorphism (p-value = 0.006)) that were nominally associated, and three variants (two variants in BDNF and one variant in the BDNF-AS locus) that were significantly associated with long-term visual memory. Our data therefore suggests a potential role for BDNF, and its anti-sense transcript BDNF-AS, in long-term visual memory performance.
Schmitter-Edgecombe, Maureen; Seelye, Adriana M
Few studies have investigated the complex nature of everyday activity memory following traumatic brain injury (TBI). This study examined recovery of content and temporal order memory for performed activities during the first year in individuals who suffered moderate to severe TBI. TBI and control participants completed eight different cognitive activities at baseline (i.e., acutely following injury for TBI) and then again approximately one year later (follow-up). Participants' free recall of the activities provided a measure of content memory. Temporal order memory was assessed with a reconstruction task. Self-report and informant report of everyday memory problems at follow-up were used to examine the relationship between activity memory performances and everyday memory. TBI participants showed significant recovery in both content and temporal order memory for activities during the first year. Despite showing significant recovery, the TBI group's activity memory performances remained poorer than that of controls at follow-up. Greater self- and informant report of everyday memory difficulties was associated with poorer temporal order memory but not content memory for activities. These findings demonstrate recovery in multiple memory processes that support activity memory following moderate to severe TBI. The findings also suggest a stronger link between everyday memory abilities and temporal order memory for activities than activity memory content in a TBI population.
Altgassen, Mareike; Vetter, Nora C; Phillips, Louise H; Akgün, Canan; Kliegel, Matthias
Research indicates ongoing development of prospective memory as well as theory of mind and executive functions across late childhood and adolescence. However, so far the interplay of these processes has not been investigated. Therefore, the purpose of the current study was to investigate whether theory of mind and executive control processes (specifically updating, switching, and inhibition) predict prospective memory development across adolescence. In total, 42 adolescents and 41 young adults participated in this study. Young adults outperformed adolescents on tasks of prospective memory, theory of mind, and executive functions. Switching and theory of mind predicted prospective memory performance in adolescents. Copyright © 2014 Elsevier Inc. All rights reserved.
K. M. Volkers
Full Text Available Background. Physical performances and cognition are positively related in cognitively healthy people. The aim of this study was to examine whether physical performances are related to specific cognitive functioning in older people with mild to severe cognitive impairment. Methods. This cross-sectional study included 134 people with a mild to severe cognitive impairment (mean age 82 years. Multiple linear regression was performed, after controlling for covariates and the level of global cognition, with the performances on mobility, strength, aerobic fitness, and balance as predictors and working memory and episodic memory as dependent variables. Results. The full models explain 49–57% of the variance in working memory and 40–43% of episodic memory. Strength, aerobic fitness, and balance are significantly associated with working memory, explaining 3–7% of its variance, irrespective of the severity of the cognitive impairment. Physical performance is not related to episodic memory in older people with mild to severe cognitive impairment. Conclusions. Physical performance is associated with working memory in older people with cognitive impairment. Future studies should investigate whether physical exercise for increased physical performance can improve cognitive functioning. This trial is registered with ClinicalTrials.gov NTR1482.
Owens, Matthew; Stevenson, Jim; Norgate, Roger; Hadwin, Julie A
Working memory skills are positively associated with academic performance. In contrast, high levels of trait anxiety are linked with educational underachievement. Based on Eysenck and Calvo's (1992) processing efficiency theory (PET), the present study investigated whether associations between anxiety and educational achievement were mediated via poor working memory performance. Fifty children aged 11-12 years completed verbal (backwards digit span; tapping the phonological store/central executive) and spatial (Corsi blocks; tapping the visuospatial sketchpad/central executive) working memory tasks. Trait anxiety was measured using the State-Trait Anxiety Inventory for Children. Academic performance was assessed using school administered tests of reasoning (Cognitive Abilities Test) and attainment (Standard Assessment Tests). The results showed that the association between trait anxiety and academic performance was significantly mediated by verbal working memory for three of the six academic performance measures (math, quantitative and non-verbal reasoning). Spatial working memory did not significantly mediate the relationship between trait anxiety and academic performance. On average verbal working memory accounted for 51% of the association between trait anxiety and academic performance, while spatial working memory only accounted for 9%. The findings indicate that PET is a useful framework to assess the impact of children's anxiety on educational achievement.
Reddi, Arumalla V.
Analyzes computer terminal memory performance in terms of overflow probability and average queueing delay, and presents new method to derive a closed expression for data arrivals with Erlangly distributed interarrival times and an approach to derive steady state probability expressions of the terminal memory content process. Twenty references are…
Shelton, Amy L.; Marchette, Steven A.
Testing spatial memory within the same environment used for learning produces interference between one's immediate representation of current position and the to-be-retrieved position. In a series of 3 experiments, we show that "current position" and its influence on memory performance can be driven by conceptual factors in an ambiguous…
Lais Dos Santos Vinholi e Silva
Full Text Available Background Memory complaints are quite common among the elderly; yet, the clinical relevance of these complaints to diagnose cognitive decline is debatable, since several different factors could be associated with them. Objective The present paper examined the correlations between memory complaints, depressive symptoms and cognitive performance in a group of 301 elderly individuals who lived in the district of Ermelino Matarazzo, São Paulo, and who participated in the population-based survey entitled Profiles of Frailty in Elderly Brazilians by the FIBRA Network. Methods Cognitive performance was assessed with the memorization test involving 10 common pictures, the Mini Mental State Examination (MMSE, the Verbal Fluency (VF test, and the Clock Drawing Test, which comprise the Brief Cognitive Screening Battery (BCSB. Memory complaints were assessed with the Memory Complaint Questionnaire (MAC-Q, and depressive symptoms with the Geriatric Depression Scale (GDS. Results Female participants had higher rates of memory complaints when compared to male participants (p = 0.013. Subjects with less years of schooling had more severe memory complaints and poorer cognitive performance than those with more years of schooling (p < 0.003. The presence of depressive symptoms was associated with poorer memory assessment scores (r = 0.39, p < 0.001. Discussion Memory complaints were correlated with sex, schooling and depressive symptoms among elderly individuals residing in the community. No correlation was found between complaints and cognitive performance.
Pacheco, Jennifer; Beevers, Christopher G.; McGeary, John E.; Schnyer, David M.
Older adults show extensive variability in cognitive performance, including episodic memory. A portion of this variability could potentially be explained by genetic factors. Recent literature shows that the neurotransmitter serotonin plays an important role in memory processes, as enhancements of brain serotonin have led to memory improvement. Here, we have begun to explore genetic contributions to the performance and underlying brain activity associated with source memory monitoring. Using a source recognition memory task during fMRI scanning, this study offers evidence that older adults who carry a short allele (S-car) of the serotonin transporter linked polymorphic region (5-HTTLPR) in the SLC6A4 gene show specific deficits in source memory monitoring relative to older adults who are homozygous for the long allele (LL). These deficits are accompanied by less neural activity in regions of prefrontal cortex that have been shown to support accurate memory monitoring. Moreover, while the older adult LL group’s behavioral performance does not differ from younger adults, their brain activation reveals evidence of compensatory activation that likely supports their higher performance level. These results provide preliminary evidence that the long-allele homozygous profile is cognitively beneficial to older adults, particularly for memory functioning. PMID:22705442
Ram-Tsur, Ronit; Faust, Miriam; Zivotofsky, Ari Z.
The present study investigates the performance of persons with reading disabilities (PRD) on a variety of sequential visual-comparison tasks that have different working-memory requirements. In addition, mediating relationships between the sequential comparison process and attention and memory skills were looked for. Our findings suggest that PRD…
Bayliss, Donna M.; Jarrold, Christopher
This study examined the contribution of individual differences in rate of forgetting to variation in working memory performance in children. One hundred and twelve children (mean age 9 years 4 months) completed 2 tasks designed to measure forgetting, as well as measures of working memory, processing efficiency, and short-term storage ability.…
Bouman, Z.; Hendriks, M.P.H.; Schmand, B.A.; Kessels, R.P.C.; Aldenkamp, A.P.
INTRODUCTION: Recognition and visual working memory tasks from the Wechsler Memory Scale-Fourth Edition (WMS-IV) have previously been documented as useful indicators for suboptimal performance. The present study examined the clinical utility of the Dutch version of the WMS-IV (WMS-IV-NL) for the
Nijdam, Mirjam J; de Vries, Giel-Jan; Gersons, Berthold P R; Olff, Miranda
Neuropsychological studies have consistently demonstrated impaired verbal memory in posttraumatic stress disorder (PTSD). Trauma-focused treatment for PTSD is thought to rely on memory, but it is largely unknown whether treatment outcome is influenced by memory performance. The aim of the study, therefore, was to examine the relationship between verbal memory performance and treatment response to trauma-focused psychotherapy. Participants were referred to our outpatient clinic and recruited between December 2003 and January 2009 upon diagnosis of PTSD according to DSM-IV. Secondary analyses of a randomized controlled trial comparing eye movement desensitization and reprocessing therapy (n = 70) and brief eclectic psychotherapy (n = 70), a cognitive-behavioral intervention, are reported. Response to treatment was measured by self-reported PTSD symptom severity (Impact of Event Scale-Revised) over 17 weeks. Pretreatment verbal memory measures (California Verbal Learning Test, Rivermead Behavioral Memory Test) were included in the mixed linear model analyses in order to investigate the influence of memory on treatment outcome. Pretreatment encoding, short-term retrieval, long-term retrieval, and recognition performance were significantly associated with treatment response in terms of self-reported PTSD symptom severity for both treatments (P ≤ .013). Receiver operating characteristic curves predicting treatment response with pretreatment memory indices showed that 75.6% of the patients could be correctly classified as responder. Poor verbal memory performance represents a risk factor for worse treatment response to trauma-focused psychotherapy. Memory measures can be helpful in determining which patients are unable to benefit from trauma-focused psychotherapy. Future research should explore how treatment perspectives of patients with poor verbal memory can be improved. ISRCTN.com identifier: ISRCTN64872147. © Copyright 2015 Physicians Postgraduate Press, Inc.
Osaka, Mariko; Yaoi, Ken; Minamoto, Takehiro; Osaka, Naoyuki
The present study investigated when emotion modulates working memory from the perspective of neural activation. Using fMRI, we measured brain activity during the encoding and retrieval phases of a reading span test (RST) that used emotional contexts. The emotional RST required participants to read sentences that elicited negative, neural or positive emotional states while they were memorizing target words from the sentences. Compared with the neutral RST, the negative RST activated the right amygdala during the reading phase. Significant activation was also found in the parahippocampal gyrus, albeit only after activation of the amygdala became comparable to that in the neutral RST. In contrast, the positive RST activated the substantia nigra during the reading phase relative to the neutral RST. These findings suggest that negative and positive emotions modulate working memory through distinctive neural circuits. We also discuss possible relationships between emotional modulation and working memory capacity.
Osaka, Mariko; Yaoi, Ken; Minamoto, Takehiro; Osaka, Naoyuki
The present study investigated when emotion modulates working memory from the perspective of neural activation. Using fMRI, we measured brain activity during the encoding and retrieval phases of a reading span test (RST) that used emotional contexts. The emotional RST required participants to read sentences that elicited negative, neural or positive emotional states while they were memorizing target words from the sentences. Compared with the neutral RST, the negative RST activated the right amygdala during the reading phase. Significant activation was also found in the parahippocampal gyrus, albeit only after activation of the amygdala became comparable to that in the neutral RST. In contrast, the positive RST activated the substantia nigra during the reading phase relative to the neutral RST. These findings suggest that negative and positive emotions modulate working memory through distinctive neural circuits. We also discuss possible relationships between emotional modulation and working memory capacity. PMID:23459220
Jonkman, Lisa M; Hurks, Petra P; Schleepen, Tamara M J
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.
Correia, Stephen; Cohen, Ronald; Gongvatana, Assawin; Ross, Skye; Olchowski, James; Devlin, Kathryn; Tashima, Karen; Navia, Bradford; Delamonte, Suzanne
Chronic systemic immune activation and inflammatory processes have been linked to brain dysfunction in medically stable HIV-infected people. We investigated the association between verbal memory performance and plasma concentrations of 13 cytokines measured using multiplexed bead array immunoassay in 74 HIV-seropositive individuals and 50 HIV-seronegative controls. Memory performance was positively related to levels of IL-8 and IFN-γ, and negatively related to IL-10 and IL-18 and to hepatitis C infection. Memory performance was not significantly related to HIV disease markers. The results indicate the importance of systemic immune and inflammatory markers to neurocognitive function in chronic and stable HIV disease. © 2013.
Cicchetti, Dante; Rogosch, Fred A.; Howe, Mark L.; Toth, Sheree L.
This investigation examined basic memory processes, cortisol, and dissociation in maltreated children. School-aged children (age range = 6-13), 143 maltreated and 174 nonmaltreated, were administered the California Verbal Learning Test-Children (D. C. Delis, J. H. Kramer, E. Kaplan, & B. A. Ober, 1994) in a week-long camp setting, daily…
Altgassen, A.M.; Kretschmer, A.; Schnitzspahn, K.M.
Studies on prospective memory (PM) development in adolescents point to age-related increases through to adulthood. The goal of the present study was to examine whether instructing adolescents to engage in an episodic prospection of themselves executing future actions (i.e., future thinking) when
Zimmermann, Thomas D; Meier, Beat
In the present study, the trajectory of prospective memory across the lifespan was investigated in a total of 200 participants from five age groups (4- to 6-year-old children, 13- to 14-year-old adolescents, 19- to 26-year-old adults, 55- to 65-year-old adults, and 65- to 75-year-old adults). In an event-based prospective memory task the prospective and the retrospective components were assessed separately. For the prospective component, the results showed better performance for adolescents and young adults than for children and 65- to 75-year-old adults. In addition, participants belonging to the latter group were more likely to forget the retrospective component after having noticed the prospective memory targets. Overall, these results indicate that across the lifespan prospective memory performance follows a similar inverted u-shape function as is well known for retrospective episodic memory.
Barral, Sandra; Cosentino, Stephanie; Christensen, Kaare
IMPORTANCE: There are genetic influences on memory ability as we age, but no specific genes have been identified. OBJECTIVE: To use a cognitive endophenotype, exceptional episodic memory (EEM) performance, derived from nondemented offspring from the Long Life Family Study (LLFS) to identify genetic...... or more offspring that exhibited exceptional memory performance were used for genome-wide linkage analysis. Adjusted multivariate linear analyses in the 40-megabase region encompassing the linkage peak were conducted using 4 independent replication data sets that included 4006 nondemented elderly...... individuals. Results of the individual replication cohorts were combined by meta-analysis. MAIN OUTCOME MEASURE: Episodic memory scores computed as the mean of the 2 standardized measures of Logical Memory IA and IIA. RESULTS: Heritability estimates indicated a significant genetic component for EEM (h2 = 0...
Schnitzspahn, Katharina Marlene; Kliegel, Matthias
This study investigated age effects in prospective memory performance within older adults. The first aim was to explore this issue by examining event- and time-based prospective memory performance in two age groups: young-old (60-75 years) and old-old adults (76-90 years). Moreover, this study for the first time investigated whether forming implementation intentions could be used to improve prospective memory in young-old and old-old adults. Results showed a general effect of age in prospective memory performance for both task types. In addition, no general effect of implementation intentions in prospective memory performance across both task types and age groups was found. However, testing implementation intention effects separately for both age groups revealed that the formation of implementation intentions enhanced prospective memory only for the young-old adults, but did not substantially affect the performance in the time-based task and even impaired it in the event-based task for the old-old adults. Findings indicate that the formation of implementation intentions might be a powerful memory strategy for young-old adults, but not for the very old.
Sarah Nadine Meissner
Full Text Available Although implicit motor sequence learning is rather well understood in young adults, effects of aging on this kind of learning are controversial. There is first evidence that working memory (WM might play a role in implicit motor sequence learning in young adults as well as in adults above the age of 65. However the knowledge about the development of these processes across the adult life span is rather limited. As the average age of our population continues to rise, a better understanding of age-related changes in motor sequence learning and potentially mediating cognitive processes takes on increasing significance. Therefore, we investigated aging effects on implicit motor sequence learning and WM. Sixty adults (18-71 years completed verbal and visuospatial n-back tasks and were trained on a serial reaction time task. Randomly varying trials served as control condition. To further assess consolidation indicated by off-line improvement and reduced susceptibility to interference, reaction times (RTs were determined 1 h after initial learning. Young and older but not middle-aged adults showed motor sequence learning. Nine out of 20 older adults (compared to one young/one middle-aged exhibited some evidence of sequence awareness. After 1 h, young and middle-aged adults showed off-line improvement. However, RT facilitation was not specific to sequence trials. Importantly, susceptibility to interference was reduced in young and older adults indicating the occurrence of consolidation. Although WM performance declined in older participants when load was high, it was not significantly related to sequence learning. The data reveal a decline in motor sequence learning in middle-aged but not in older adults. The use of explicit learning strategies in older adults might account for the latter result.
Schroeder, Susan A.; Cornicelli, Louis; Fulton, David C.; Merchant, Steven S.
Although research has advanced methods for clarifying factors that relate to customer satisfaction, they have not been embraced by leisure researchers. Using results from a survey of wild turkey hunters, we applied traditional and revised importance-performance (IPA/RIPA), importance-grid analysis (IGA), and penalty-reward-contrast analysis (PRCA) to examine how activity-specific factors influenced satisfaction. Results suggested differences between the explicit and implicit importance of factors related to turkey hunting. Opportunities to kill turkeys were explicitly rated as less important than seeing, hearing, or calling in turkeys, but opportunities for harvest had relatively higher levels of implicit importance. PRCA identified “calling turkeys in” and “hearing gobbling” as minimum requirements that cause dissatisfaction if not fulfilled, but do not provide satisfaction, whereas “seeing turkeys” and an “opportunity to kill a turkey” related to both satisfaction and dissatisfaction. RIPA, IGA, and PRCA could provide valuable insights about factors that may improve satisfaction for leisure participants.
Full Text Available Episodic memory is typically better for items coupled with monetary reward or punishment during encoding. It is yet unclear whether memory is also enhanced for everyday objects with appetitive or aversive values learned through a lifetime of experience, and to what extent episodic memory enhancement for motivational and neutral items is attributable to attention. In a first experiment, we investigated attention to everyday motivational objects using eye-tracking during free-viewing and subsequently tested episodic memory using a remember/know procedure. Attention was directed more to aversive stimuli, as evidenced by longer viewing durations, whereas recollection was higher for both appetitive and aversive objects. In the second experiment, we manipulated the visual contrast of neutral objects through changes of contrast to further dissociate attention and memory encoding. While objects presented with high visual contrast were looked at longer, recollection was best for objects presented in unmodified, medium contrast. Generalized logistic mixed models on recollection performance showed that attention as measured by eye movements did not enhance subsequent memory, while motivational value (Experiment 1 and visual contrast (Experiment 2 had quadratic effects in opposite directions. Our findings suggest that an enhancement of incidental memory encoding for appetitive items can occur without an increase in attention and, vice versa, that enhanced attention towards salient neutral objects is not necessarily associated with memory improvement. Together, our results provide evidence for a double dissociation of attention and memory effects under certain conditions.
Schoo, Linda A; van Zandvoort, Martine J E; Reijmer, Yael D; Biessels, Geert Jan; Kappelle, L Jaap; Postma, Albert
Reconstructing the temporal order of events is a crucial part of episodic memory. The temporal dimension, however, is often discarded in clinical settings, and measurements of true temporal aspects of episodic memory are scarce. The present study assessed temporal memory in stroke patients and in age- and education-matched healthy controls. Both groups underwent a standardized neuropsychological examination. We asked participants afterwards to reconstruct the order of tests they had performed, measured in absolute temporal order (event placed on correct moment in sequence) and relative temporal order (event placed correctly relative to directly preceding and following events). The aim of the study was to examine how serial-position curve effects (measuring absolute temporal order anchored in exact time) and how relative temporal order memory (anchored to other events) may differ in a group of cerebral stroke patients. Another aim was to link temporal order memory deficits with established neuropsychological measures of cognitive functioning. Although item identification was comparable in both groups, absolute temporal order memory was impaired in patients: A total of 43% of the patients lacked the expected primacy and recency effects (serial position effect). In addition, relative temporal order memory was affected in this group as well, F(1, 70) = 4.08, p < .05; 25% of the patients were impaired in reconstructing the relative temporal order (p = .019, Fisher's Exact Test). Both absolute and relative temporal order memory performance related to the domains of executive functioning and memory. Our results suggest that it is important to test both absolute and relative temporal order memory, especially because these types of memory depend on different anchors, either on time or on adjacent events.
MOHAMMED FAIZ ABOALMAALY
Full Text Available With the continuous revolution of multicore architecture, several parallel programming platforms have been introduced in order to pave the way for fast and efficient development of parallel algorithms. Back into its categories, parallel computing can be done through two forms: Data-Level Parallelism (DLP or Task-Level Parallelism (TLP. The former can be done by the distribution of data among the available processing elements while the latter is based on executing independent tasks concurrently. Most of the parallel programming platforms have built-in techniques to distribute the data among processors, these techniques are technically known as automatic distribution (scheduling. However, due to their wide range of purposes, variation of data types, amount of distributed data, possibility of extra computational overhead and other hardware-dependent factors, manual distribution could achieve better outcomes in terms of performance when compared to the automatic distribution. In this paper, this assumption is investigated by conducting a comparison between automatic and our newly proposed manual distribution of data among threads in parallel. Empirical results of matrix addition and matrix multiplication show a considerable performance gain when manual distribution is applied against automatic distribution.
T. den Heijer (Tom); M.I. Geerlings (Miriam); F.H. de Jong (Frank); L.J. Launer (Lenore); H.A.P. Pols (Huib); M.M.B. Breteler (Monique); A. Hofman (Albert)
textabstractBACKGROUND: Estrogens may prevent cognitive decline and Alzheimer disease. Animal study findings have shown beneficial effects of estrogen on the brain, particularly on the hippocampus, a structure related to memory performance and early Alzheimer disease. OBJECTIVE:
De Haan, Edward H. F; Appels, Bregje; Aleman, André; Postma, Albert
... using visual and auditory presentation and writing and vocalization as encoding activities. The results show a similar memory performance in all conditions apart from the one in which visually presented words had to be written down...
Alice Milani Nespollo
Full Text Available ABSTRACT Objective: to verify the correlation between health condition and memory performance of older adult women in the community. Method: Analytical cross-sectional study developed with 28 older adult women living in Cuiabá-MT. They answered the Mini-Mental State Examination (MMSE, and a shortened Geriatric Depression Scale (GDS-15 to screen for dementia and depression symptoms. Memory skills were assessed through Rey Auditory Verbal Learning Test (RAVLT. Results: The mean age was 66.36 years and 75% of the participants had educational level higher than 7 years. The MMSE mean score was 28.45. The correlations found were: educational level and immediate memory (r = 0.49; p = 0.008; delayed recall and immediate memory (r = 0.71; p < 0.001; memory recognition and immediate memory (r = 0.43; p = 0.021 and recognition memory with delayed recall (r = 0.47; p = 0.012. Conclusion: High scores in the MMSE and a satisfactory health perception among the participants were evident. There was no correlation between memory performance and health perception.
Cammisuli, Davide Maria; Sportiello, Marco Timpano
Memory system turns out to be one of the cognitive domains most severely impaired in schizophrenia. Within the theoretical framework of cognitive psychopathology, we compared the performance of schizophrenia patients on the Wechsler Memory Scale-IV with that in matched patients with Obsessive-compulsive disorder and that in healthy control subjects to establish the specific nature of memory deficits in schizophrenia. 30 schizophrenia patients, 30 obsessive-compulsive disorder patients and 40 healthy controls completed the Wechsler Memory Scale-IV. Schizophrenia symptom severity was assessed by the Positive and Negative Syndrome Scale (PANSS). Performances on memory battery including Indexes and subtests scores were compared by a One-Way ANOVA (Scheffé post-hoc test). Spearman Rank correlations were performed between scores on PANSS subscales and symptoms and WMS-IV Indexes and subtests, respectively. Schizophrenia patients showed a memory profile characterized by mild difficulties in auditory memory and visual working memory and poor functioning of visual, immediate and delayed memory. As expected, schizophrenia patients scored lower than healthy controls on all WMS-IV measures. With regard to the WMS-IV Indexes, schizophrenia patients performed worse on Auditory Memory, Visual Memory, Immediate and Delayed Memory than Obsessive-compulsive disorder patients but not on Visual Working Memory. Such a pattern was made even clearer for specific tasks such as immediate and delayed recall and spatial recall and memory for visual details, as revealed by the lowest scores on Logical Memory (immediate and delayed conditions) and Designs (immediate condition) subtests, respectively. Significant negative correlations between Logical Memory I and II were found with PANSS Excitement symptom as well as between DE I and PANSS Tension symptom. Significant positive correlations between LM II and PANSS Blunted affect and Poor rapport symptoms as well as DE I and PANSS Blunted affect
Zanto, Theodore P.; Gazzaley, Adam
Our ability to focus attention on task-relevant information and ignore distractions is reflected by differential enhancement and suppression of neural activity in sensory cortex (i.e., top-down modulation). Such selective, goal-directed modulation of activity may be intimately related to memory, such that the focus of attention biases the likelihood of successfully maintaining relevant information by limiting interference from irrelevant stimuli. Despite recent studies elucidating the mechani...
Kessel, van L.
In their performance Timelining, Brennan Gerard and Ryan Kelly explore the ways in which intimate relationships are constituted in time. The performance consists of a memory game in which two performers retrace their shared history as a couple. Throughout the performance, the various actions
Van Rooijen, Maaike; Verhoeven, Ludo; Steenbergen, Bert
Early numeracy is an important precursor for arithmetic performance, academic proficiency, and work success. Besides their apparent motor difficulties, children with cerebral palsy (CP) often show additional cognitive disturbances. In this study, we examine whether working memory, non-verbal intelligence, linguistic skills, counting and fine motor skills are positively related to the early numeracy performance of 6-year-old children with CP. A total of 56 children (M = 6.0, SD = 0.61, 37 boys) from Dutch special education schools participated in this cross-sectional study. Of the total group, 81% of the children have the spastic type of CP (33% unilateral and 66% bilateral), 9% have been diagnosed as having diskinetic CP, 8% have been diagnosed as having spastic and diskinetic CP and 2% have been diagnosed as having a combination of diskinetic and atactic CP. The children completed standardized tests assessing early numeracy performance, working memory, non-verbal intelligence, sentence understanding and fine motor skills. In addition, an experimental task was administered to examine their basic counting performance. Structural equation modeling showed that working memory and fine motor skills were significantly related to the early numeracy performance of the children (β = .79 and p memory and early numeracy (β = .57, p memory for early numeracy performance in children with CP and they warrant further research into the efficacy of intervention programs aimed at working memory training.
Riccio, Cynthia A; Cash, Deborah L; Cohen, Morris J
The purpose of this study was to examine learning and memory in children with Specific Language Impairment (SLI) as compared to 30 normally functioning children on the Children's Memory Scale. Results indicated that children in the SLI group exhibited impaired performance on the Attention/Concentration Index (working memory), as well as significantly lower scores on both the immediate and delayed auditory/verbal indices and subtests relative to the control group. In contrast, no between group differences emerged for the visual/non-verbal indices and subtests. Results demonstrated that children with SLI possess normal ability to process, maintain and manipulate visual/non-verbal information in working memory along with normal ability to store and retrieve visual/non-verbal material from long-term storage. These results provide support for the contention that children with SLI have a "diminished verbal capacity" to process, organize, and maintain auditory information in working memory.
Curiel, Ashley R; Miller, Karen J; Pollard, Karen; Kim, Jeanne; Kravitz, Jena; Small, Gary W
Aims The current study sought to explore the relationship between state and trait anxiety and delayed verbal memory performance in APOE-4 carriers and noncarriers who were aged 50 years and above. Materials & methods The study was a retrospective analysis of 267 participants aged 50 years and above who had completed genetic testing for APOE status, the State-Trait Anxiety Inventory, and a comprehensive neuropsychological battery that included three delayed verbal memory measures (Wechsler Memory Scale – 3rd Edition, Logical Memory and Verbal Pairs subtests and the Buschke Selective Reminding Test). Results An inverse relationship was found between state anxiety and delayed verbal memory performance. No difference in level of anxiety was found between APOE-4 carriers versus noncarriers. Conclusion State anxiety, but not trait anxiety, was found to have an inverse relationship with delayed verbal memory performance. For example, as self-reported state anxiety increased, delayed verbal memory scores decreased. This relationship did not appear to be influenced by the presence or absence of the APOE-4 allele. PMID:22905036
Full Text Available Graphics processors (GPU -- Graphic Processor Units recently have gained a lot of interest as an efficient platform for general-purpose computation. Cellular Automata approach which is inherently parallel gives the opportunity to implement high performance simulations. This paper presents how shared memory in GPU can be used to improve performance for Cellular Automata models. In our previous works, we proposed algorithms for Cellular Automata model that use only a GPU global memory. Using a profiling tool, we found bottlenecks in our approach. We introduce modifications that takes an advantage of fast shared memory. The modified algorithm is presented in details, and the results of profiling and performance test are demonstrated. Our unique achievement is comparing the efficiency of the same algorithm working with a global and shared memory.
Lee, Kerry; Ning, Flora; Goh, Hui Chin
Although the effects of achievement goals and working memory on academic performance are well established, it is not clear whether they jointly affect academic performance. Children from Primary 4 and 6 (N = 608) were administered (a) measures of working memory and updating from the automated working memory battery and a running span task, (b)…
Ribordy Lambert, Farfalla; Lavenex, Pierre; Banta Lavenex, Pamela
Allocentric spatial memory, "where" with respect to the surrounding environment, is one of the three fundamental components of episodic memory: what, where, when. Whereas basic allocentric spatial memory abilities are reliably observed in children after 2 years of age, coinciding with the offset of infantile amnesia, the resolution of allocentric spatial memory acquired over repeated trials improves from 2 to 4 years of age. Here, we first show that single-trial allocentric spatial memory performance improves in children from 3.5 to 7 years of age, during the typical period of childhood amnesia. Second, we show that large individual variation exists in children's performance at this age. Third, and most importantly, we show that improvements in single-trial allocentric spatial memory performance are due to an increasing ability to spatially and temporally separate locations and events. Such improvements in spatial and temporal processing abilities may contribute to the gradual offset of childhood amnesia. © 2016 Wiley Periodicals, Inc.
Buckert, Magdalena; Kudielka, Brigitte M; Reuter, Martin; Fiebach, Christian J
One of the most widely studied genetic polymorphisms regarding cognitive and emotional phenotypes is the COMT Val158Met polymorphism that influences dopamine availability in the prefrontal cortex (PFC). The PFC is the key brain structure for higher cognitive functions such as working memory, as well as an important regulatory site and target of the psychoendocrine stress response. Dopamine is thought to influence PFC functions in an inverted u-shaped manner. Thus, a stress-related increase in prefrontal dopamine is hypothesized to exert differential effects on working memory performance depending on the genetically determined baseline dopamine level in the PFC. Thirty-three healthy young subjects homozygous for the COMT Val158Met polymorphism were selected from a larger pre-genotyped sample. They performed an n-back working memory task after exposure to a laboratory psychosocial stress induction paradigm (The Trier Social Stress Test for Groups; TSST-G). Under stress, working memory performance of Met homozygotes was significantly worse than working memory performance of Val homozygotes. Importantly, this genotype effect was restricted to the medium difficulty level of the n-back task. Our results demonstrate that working memory performance under stress is influenced by genetic variation in prefrontal dopamine levels. More generally, our results point to the importance of considering the complex interaction of genes, environment, and task variables. Copyright © 2012 Elsevier Ltd. All rights reserved.
Vercammen, Charlotte; Goossens, Tine; Wouters, Jan; van Wieringen, Astrid
The main objective of this study is to investigate memory task performance in different age groups, irrespective of hearing status. Data are collected on a short-term memory task (WAIS-III Digit Span forward) and two working memory tasks (WAIS-III Digit Span backward and the Reading Span Test). The tasks are administered to young (20-30 years, n = 56), middle-aged (50-60 years, n = 47), and older participants (70-80 years, n = 16) with normal hearing thresholds. All participants have passed a cognitive screening task (Montreal Cognitive Assessment (MoCA)). Young participants perform significantly better than middle-aged participants, while middle-aged and older participants perform similarly on the three memory tasks. Our data show that older clinically normal hearing persons perform equally well on the memory tasks as middle-aged persons. However, even under optimal conditions of preserved sensory processing, changes in memory performance occur. Based on our data, these changes set in before middle age.
Sprague, Samantha A; McBee, Matthew T; Sellers, Eric W
The purpose of the present study is to evaluate the relationship between working memory and BCI performance. Participants took part in two separate sessions. The first session consisted of three computerized tasks. The List Sorting Working Memory Task was used to measure working memory, the Picture Vocabulary Test was used to measure general intelligence, and the Dimensional Change Card Sort Test was used to measure executive function, specifically cognitive flexibility. The second session consisted of a P300-based BCI copy-spelling task. The results indicate that both working memory and general intelligence are significant predictors of BCI performance. This suggests that working memory training could be used to improve performance on a BCI task. Working memory training may help to reduce a portion of the individual differences that exist in BCI performance allowing for a wider range of users to successfully operate the BCI system as well as increase the BCI performance of current users. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.
Mazzoni, Pietro; Wexler, Nancy S
Human movement can be guided automatically (implicit control) or attentively (explicit control). Explicit control may be engaged when learning a new movement, while implicit control enables simultaneous execution of multiple actions. Explicit and implicit control can often be assigned arbitrarily: we can simultaneously drive a car and tune the radio, seamlessly allocating implicit or explicit control to either action. This flexibility suggests that sensorimotor signals, including those that encode spatially overlapping perception and behavior, can be accurately segregated to explicit and implicit control processes. We tested human subjects' ability to segregate sensorimotor signals to parallel control processes by requiring dual (explicit and implicit) control of the same reaching movement and testing for interference between these processes. Healthy control subjects were able to engage dual explicit and implicit motor control without degradation of performance compared to explicit or implicit control alone. We then asked whether segregation of explicit and implicit motor control can be selectively disrupted by studying dual-control performance in subjects with no clinically manifest neurologic deficits in the presymptomatic stage of Huntington's disease (HD). These subjects performed successfully under either explicit or implicit control alone, but were impaired in the dual-control condition. The human nervous system can exert dual control on a single action, and is therefore able to accurately segregate sensorimotor signals to explicit and implicit control. The impairment observed in the presymptomatic stage of HD points to a possible crucial contribution of the striatum to the segregation of sensorimotor signals to multiple control processes.
Full Text Available Human movement can be guided automatically (implicit control or attentively (explicit control. Explicit control may be engaged when learning a new movement, while implicit control enables simultaneous execution of multiple actions. Explicit and implicit control can often be assigned arbitrarily: we can simultaneously drive a car and tune the radio, seamlessly allocating implicit or explicit control to either action. This flexibility suggests that sensorimotor signals, including those that encode spatially overlapping perception and behavior, can be accurately segregated to explicit and implicit control processes.We tested human subjects' ability to segregate sensorimotor signals to parallel control processes by requiring dual (explicit and implicit control of the same reaching movement and testing for interference between these processes. Healthy control subjects were able to engage dual explicit and implicit motor control without degradation of performance compared to explicit or implicit control alone. We then asked whether segregation of explicit and implicit motor control can be selectively disrupted by studying dual-control performance in subjects with no clinically manifest neurologic deficits in the presymptomatic stage of Huntington's disease (HD. These subjects performed successfully under either explicit or implicit control alone, but were impaired in the dual-control condition.The human nervous system can exert dual control on a single action, and is therefore able to accurately segregate sensorimotor signals to explicit and implicit control. The impairment observed in the presymptomatic stage of HD points to a possible crucial contribution of the striatum to the segregation of sensorimotor signals to multiple control processes.
Tam, Shu K E; Hasan, Sibah; Hughes, Steven; Hankins, Mark W; Foster, Russell G; Bannerman, David M; Peirson, Stuart N
Acute light exposure exerts various effects on physiology and behaviour. Although the effects of light on brain network activity in humans are well demonstrated, the effects of light on cognitive performance are inconclusive, with the size, as well as direction, of the effect depending on the nature of the task. Similarly, in nocturnal rodents, bright light can either facilitate or disrupt performance depending on the type of task employed. Crucially, it is unclear whether the effects of light on behavioural performance are mediated via the classical image-forming rods and cones or the melanopsin-expressing photosensitive retinal ganglion cells. Here, we investigate the modulatory effects of light on memory performance in mice using the spontaneous object recognition task. Importantly, we examine which photoreceptors are required to mediate the effects of light on memory performance. By using a cross-over design, we show that object recognition memory is disrupted when the test phase is conducted under a bright light (350 lux), regardless of the light level in the sample phase (10 or 350 lux), demonstrating that exposure to a bright light at the time of test, rather than at the time of encoding, impairs performance. Strikingly, the modulatory effect of light on memory performance is completely abolished in both melanopsin-deficient and rodless-coneless mice. Our findings provide direct evidence that melanopsin-driven and rod/cone-driven photoresponses are integrated in order to mediate the effect of light on memory performance. © 2016 The Authors.
Browne, Wendy V; Hindmarsh, Peter C; Pasterski, Vickie; Hughes, Ieuan A; Acerini, Carlo L; Spencer, Debra; Neufeld, Sharon; Hines, Melissa
Individuals with classic congenital adrenal hyperplasia (CAH) experience impaired glucocorticoid production and are treated postnatally with glucocorticoids. Prior research with animals and other human populations indicates that glucocorticoids can influence memory, particularly working memory. We tested the hypothesis that children with CAH would show reduced working memory. Children in the United Kingdom, aged 7-11years, with classical CAH (31 girls, 26 boys) were compared to their unaffected relatives (30 girls, 20 boys) on a test of working memory, the Digit Span test. Vocabulary was also assessed to measure verbal intelligence for control purposes. Children with CAH showed reduced working memory performance compared to controls, on both components of the Digit Span test: p=.008 for Digit Span Forward, and p=.027 for Digit Span Backward, and on a composite score, p=.004. These differences were of moderate size (d=.53 to .70). Similar differences were also seen in a subset of 23 matched pairs of children with CAH and their relatives (d=.78 to .92). There were no group differences on Vocabulary. Glucocorticoid abnormality, including treatment effects, could be responsible for the reduced Digit Span performance in children with CAH. Other factors related to CAH, such as salt-wasting crises, could also be involved. Additional research is needed to identify the cause of the memory reduction, which will help to determine if more rapid diagnosis or more precise glucocorticoid treatment would help prevent memory reduction. Educational interventions might also be considered for children with CAH. Copyright © 2014 Elsevier Inc. All rights reserved.
Sajid, Irfan; Ahmad, Saara; Emad, Shaista; Batool, Zehra; Khaliq, Saima; Anis, Lubna; Tabassum, Saiqa; Madiha, Syeda; Liaquat, Laraib; Sadir, Sadia; Perveen, Tahira; Haider, Saida
Energy drinks enhance physical endurance and cognitive ability. The ingredients present in these drinks are considered as ergogenic and have memory boosting effects. In the present study effects of taurine administration for one week was monitored on physical exercise and memory performance in rats. Animals were divided into two groups namely control and test. Taurine was injected intraperitoneally to the test group at the dose of 100mg/kg. After one week of treatment rats were subjected to physical exercise and memory task. Results of this study revealed that rats injected with taurine for one week exhibited improved muscular strength as well as enhanced memory performance in Morris water maze and elevated plus maze. Biomarker of lipid peroxidation was significantly reduced in brain and plasma of test animals. Taurine administration also resulted in higher levels of corticosterone in this study. The results highlight the significance of taurine ingestion in energy demanding and challenging situations in athletes and young subjects.
Lindeløv, Jonas Kristoffer; Overgaard, Rikke; Overgaard, Morten
Working memory impairment is prevalent in brain injured patients across lesion aetiologies and severities. Unfortunately, rehabilitation efforts for this impairment have hitherto yielded small or no effects. Here we show in a randomized actively controlled trial that working memory performance can...... be effectively restored by suggesting to hypnotized patients that they have regained their pre-injury level of working memory functioning. Following four 1-h sessions, 27 patients had a medium-sized improvement relative to 22 active controls (Bayes factors of 342 and 37.5 on the two aggregate outcome measures...... group was crossed over to the working memory suggestion and showed superior improvement. By the end of the study, both groups reached a performance level at or above the healthy population mean with standardized mean differences between 1.55 and 2.03 relative to the passive control group. We conclude...
Bäckman, L; Hill, R D; Herlitz, A; Fratiglioni, L; Winblad, B
Whether individual differences in demographic, psychometric, and biological domains can predict episodic memory in dementia was investigated. Mildly to moderately demented very old persons performed episodic memory tasks (free recall and recognition of slowly and rapidly presented random words, free and cued recall of organizable words, and recognition of dated and contemporary famous faces). A factor analysis of the memory measures yielded 2 factors, 1 indexing recall and 1 recognition. Controlling for severity of dementia, only 2 predictors contributed to performance: (a) Block Design (a marker of fluid intelligence) was positively related to recall, and (b) age was negatively related to recognition. Although these results are similar to data reported on predictors of episodic memory in normal aging, (a) the number of predictive variables appears to be reduced in dementia, and (b) age seems to affect recall and recognition differentially in normal aging and dementia.
Full Text Available Short-term memory requires the coordination of sub-processes like encoding, retention, retrieval and comparison of stored material to subsequent input. Neuronal oscillations have an inherent time structure, can effectively coordinate synaptic integration of large neuron populations and could therefore organize and integrate distributed sub-processes in time and space. We observed field potential oscillations (14-95Hz in ventral prefrontal cortex of monkeys performing a visual memory task. Stimulus-selective and performance-dependent oscillations occurred simultaneously at 65-95Hz and 14-50Hz, the latter being phase-locked throughout memory maintenance. We propose that prefrontal oscillatory activity may be instrumental for the dynamical integration of local and global neuronal processes underlying short-term memory.
Brand, Judith, Ed.
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,…
Lydia T.S. Yee
Full Text Available Traditionally, it has been proposed that the hippocampus and adjacent medial temporal lobe cortical structures are selectively critical for long-term declarative memory, which entails memory for inter-item and item-context relationships. Whether the hippocampus might also contribute to short-term retention of relational memory representations has remained controversial. In two experiments, we revisit this question by testing memory for relationships among items embedded in scenes using a standard working memory trial structure in which a sample stimulus is followed by a brief delay and the corresponding test stimulus. In each experimental block, eight trials using different exemplars of the same scene were presented. The exemplars contained the same items but with different spatial relationships among them. By repeating the pictures across trials, any potential contributions of item or scene memory to performance were minimized, and relational memory could be assessed more directly than has been done previously. When test displays were presented, participants indicated whether any of the item-location relationships had changed. Then, regardless of their responses (and whether any item did change its location, participants indicated on a forced-choice test, which item might have moved, guessing if necessary. Amnesic patients were impaired on the change detection test, and were frequently unable to specify the change after having reported correctly that a change had taken place. Comparison participants, by contrast, frequently identified the change even when they failed to report the mismatch, an outcome that speaks to the sensitivity of the change specification measure. These results confirm past reports of hippocampal contributions to short-term retention of relational memory representations, and suggest that the role of the hippocampus in memory has more to do with relational memory requirements than the length of a retention interval.
Singer, Philipp; Hauser, Jonas; Llano Lopez, Luis; Peleg-Raibstein, Daria; Feldon, Joram; Gargiulo, Pascual A; Yee, Benjamin K
Prepulse inhibition (PPI) of the acoustic startle reflex refers to the attenuation of the startle response to an intense pulse stimulus when it is shortly preceded by a weak non-startling prepulse stimulus. It is a well-established high-throughput translational measure of pre-attentive sensory gating, and its impairment is detected in several neuropsychiatric diseases including schizophrenia. It has been hypothesized that PPI might be associated with, or predictive of, cognitive deficiency in such diseases, and therefore provide an efficient assay for screening drugs with potential pro-cognitive efficacy. Free from any predetermined disease model, the present study evaluated in a homogeneous cohort of inbred C57BL/6 mice the presence of a statistical link between PPI expression and cognitive performance. Performance indices in a spatial reference memory test and a working memory test conducted in the Morris water maze, and contextual fear conditioning were correlated against pre-existing baseline PPI expression. A specific correlative link between working memory and PPI induced by weak (but not strong) prepulse was revealed. In addition, a correlation between habituation of the startle reflex and reference memory was identified for the first time: a stronger overt habituation effect was associated with superior spatial search accuracy. The PPI paradigm thus provides two independent predictors of dissociable cognitive traits in normal C57BL/6 mice; and they might serve as potential markers for high-throughput evaluation of potential cognitive enhancers, especially in the context of schizophrenia where deficits in startle habituation and PPI co-exist. Copyright © 2012 Elsevier B.V. All rights reserved.
Seadatee-Shamir, Abootaleb; Soleimanian, AliAkbar; Zahmatkesh, Zeinab; Mahdian, Hossein
The relationship among WMC (working memory capacity), reading performance and academic achievement is both logically and theoretically undisputable. However, what may not be as obvious is that such capacity and performance, and as a result, achievement, could be higher among ECBL (early childhood bilingual) students. To reaffirm the obvious and…
Bendtsen, Claus Nørgaard; Krink, Thiemo
Real-world problems are often nonstationary and can cause cyclic, repetitive patterns in the search landscape. For this class of problems, we introduce a new GA with dynamic explicit memory, which showed superior performance compared to a classic GA and a previously introduced memory-based GA...... for two dynamic benchmark problems...
Evans, Theodore A; Perdue, Bonnie; Beran, Michael J
Prospective memory is remembering to do something at a future time. A growing body of research supports that prospective memory may exist in nonhuman animals, but the methods used to test nonhuman prospective memory differ from those used with humans. The current work tests prospective memory in chimpanzees using a method that closely approximates a typical human paradigm. In these experiments, the prospective memory cue was embedded within an ongoing task. Tokens representing food items could be used in one of two ways: in a matching task with pictures of items (the ongoing task) or to request a food item hidden in a different location at the beginning of the trial. Chimpanzees had to disengage from the ongoing task in order to use the appropriate token to obtain a higher preference food item. In Experiment 1, chimpanzees effectively matched tokens to pictures, when appropriate, and disengaged from the ongoing task when the token matched the hidden item. In Experiment 2, performance did not differ when the target item was either hidden or visible. This suggested no effect of cognitive load on either the prospective memory task or the ongoing task, but performance was near ceiling, which may have contributed to this outcome. In Experiment 3, we created a more challenging version of the task. More errors on the matching task occurred before the prospective memory had been carried out, and this difference seemed to be limited to the hidden condition. This finding parallels results from human studies and suggests that working memory load and prospective memory may have a similar relationship in nonhuman primates.
Theodore A Evans
Full Text Available Prospective memory is remembering to do something at a future time. A growing body of research supports that prospective memory may exist in nonhuman animals, but the methods used to test nonhuman prospective memory differ from those used with humans. The current work tests prospective memory in chimpanzees using a method that closely approximates a typical human paradigm. In these experiments, the prospective memory cue was embedded within an ongoing task. Tokens representing food items could be used in one of two ways: in a matching task with pictures of items (the ongoing task or to request a food item hidden in a different location at the beginning of the trial. Chimpanzees had to disengage from the ongoing task in order to use the appropriate token to obtain a higher preference food item. In Experiment 1, chimpanzees effectively matched tokens to pictures, when appropriate, and disengaged from the ongoing task when the token matched the hidden item. In Experiment 2, performance did not differ when the target item was either hidden or visible. This suggested no effect of cognitive load on either the prospective memory task or the ongoing task, but performance was near ceiling, which may have contributed to this outcome. In Experiment 3, we created a more challenging version of the task. More errors on the matching task occurred before the prospective memory had been carried out, and this difference seemed to be limited to the hidden condition. This finding parallels results from human studies and suggests that working memory load and prospective memory may have a similar relationship in nonhuman primates.
Zalla, Tiziana; Daprati, Elena; Sav, Anca-Maria; Chaste, Pauline; Nico, Daniele; Leboyer, Marion
Memory for action is enhanced if individuals are allowed to perform the corresponding movements, compared to when they simply listen to them (enactment effect). Previous studies have shown that individuals with Autism Spectrum Disorders (ASD) have difficulties with processes involving the self, such as autobiographical memories and self performed actions. The present study aimed at assessing memory for action in Asperger Syndrome (AS). We investigated whether adults with AS would benefit from the enactment effect when recalling a list of previously performed items vs. items that were only visually and verbally experienced through three experimental tasks (Free Recall, Old/New Recognition and Source Memory). The results showed that while performance on Recognition and Source Memory tasks was preserved in individuals with AS, the enactment effect for self-performed actions was not consistently present, as revealed by the lower number of performed actions being recalled on the Free Recall test, as compared to adults with typical development. Subtle difficulties in encoding specific motor and proprioceptive signals during action execution in individuals with AS might affect retrieval of relevant personal episodic information. These disturbances might be associated to an impaired action monitoring system. PMID:20967277
Full Text Available Memory for action is enhanced if individuals are allowed to perform the corresponding movements, compared to when they simply listen to them (enactment effect. Previous studies have shown that individuals with Autism Spectrum Disorders (ASD have difficulties with processes involving the self, such as autobiographical memories and self performed actions. The present study aimed at assessing memory for action in Asperger Syndrome (AS. We investigated whether adults with AS would benefit from the enactment effect when recalling a list of previously performed items vs. items that were only visually and verbally experienced through three experimental tasks (Free Recall, Old/New Recognition and Source Memory. The results showed that while performance on Recognition and Source Memory tasks was preserved in individuals with AS, the enactment effect for self-performed actions was not consistently present, as revealed by the lower number of performed actions being recalled on the Free Recall test, as compared to adults with typical development. Subtle difficulties in encoding specific motor and proprioceptive signals during action execution in individuals with AS might affect retrieval of relevant personal episodic information. These disturbances might be associated to an impaired action monitoring system.
Foster, Erin R; McDaniel, Mark A; Repovs, Grega; Hershey, Tamara
Prospective memory is a complex cognitive construct ubiquitous in everyday life that is thought to sometimes rely on executive skills commonly affected by Parkinson's disease (PD). The present study investigated the effect of PD on prospective memory tasks with varying demand on executive control processes, namely on the amount of strategic attentional monitoring required for intention retrieval. Individuals with PD but without dementia and healthy adults performed laboratory event-based prospective memory tasks that varied in whether strategic attentional monitoring (nonfocal condition) or spontaneous processes (focal condition) were primarily involved in intention retrieval. Participants also completed a questionnaire rating their frequency of prospective memory failures in everyday life for both self-cued and environment-cued tasks. PD participants performed worse than non-PD participants in the nonfocal, but not focal, condition of the laboratory task. They also reported more everyday failures than non-PD participants for self-cued, but not environment-cued, prospective memory tasks. Thus, nondemented individuals with PD are preferentially impaired on prospective memory tasks for which higher levels of executive control are needed to support intention retrieval. This pattern is consistent across laboratory and reported real-world performance.
Walsh, Megan; Montojo, Caroline A; Sheu, Yi-Shin; Marchette, Steven A; Harrison, Daniel M; Newsome, Scott D; Zhou, Feng; Shelton, Amy L; Courtney, Susan M
Re-entrant circuits involving communication between the frontal cortex and other brain areas have been hypothesized to be necessary for maintaining the sustained patterns of neural activity that represent information in working memory, but evidence has so far been indirect. If working memory maintenance indeed depends on such temporally precise and robust long-distance communication, then performance on a delayed recognition task should be highly dependent on the microstructural integrity of white-matter tracts connecting sensory areas with prefrontal cortex. This study explored the effect of variations in white-matter microstructure on working memory performance in two separate groups of participants: patients with multiple sclerosis and age- and sex-matched healthy adults. Functional magnetic resonance imaging was performed to reveal cortical regions involved in spatial and object working memory, which, in turn, were used to define specific frontal to extrastriate white-matter tracts of interest via diffusion tensor tractography. After factoring out variance due to age and the microstructure of a control tract (the corticospinal tract), the number of errors produced in the object working memory task was specifically related to the microstructure of the inferior frontal-occipital fasciculus. This result held for both groups, independently, providing a within-study replication with two different types of white-matter structural variability: multiple sclerosis-related damage and normal variation. The results demonstrate the importance of interactions between specific regions of the prefrontal cortex and sensory cortices for a nonspatial working memory task that preferentially activates those regions.
Guez, Jonathan; Saar-Ashkenazy, Rotem; Mualem, Liran; Efrati, Matan; Keha, Eldad
The effect of emotional arousal on memory presents a complex pattern with previous studies reporting conflicting results of both improved and reduced memory performance following arousal manipulations. In this study we further tested the effect of negative emotional arousal (NEA) on individual-item recognition and associative recognition of neutral stimuli in healthy participants, and hypothesized that NEA will particularly impair associative memory performance. The current study consists of two experiments; in both, participants studied a list of word-pairs and were then tested for items (items recognition test), and for associations (associative recognition test). In the first experiment, the arousal manipulation was induced by flashing emotionally-negative or neutral pictures between study-pairs while in the second experiment arousal was induced by presenting emotionally-negative or neutral pictures between lists. The results of the two experiments converged and supported an associative memory deficit observed under NEA conditions. We suggest that NEA is associated with an altered ability to bind one stimulus to another as a result of impaired recollection, resulting in poorer associative memory performance. The current study findings may contribute to the understanding of the mechanism underlying memory impairments reported in disorders associated with traumatic stress.
Full Text Available The effect of emotional arousal on memory presents a complex pattern with previous studies reporting conflicting results of both improved and reduced memory performance following arousal manipulations. In this study we further tested the effect of negative emotional arousal (NEA on individual-item recognition and associative recognition of neutral stimuli in healthy participants, and hypothesized that NEA will particularly impair associative memory performance. The current study consists of two experiments; in both, participants studied a list of word-pairs and were then tested for items (items recognition test, and for associations (associative recognition test. In the first experiment, the arousal manipulation was induced by flashing emotionally-negative or neutral pictures between study-pairs while in the second experiment arousal was induced by presenting emotionally-negative or neutral pictures between lists. The results of the two experiments converged and supported an associative memory deficit observed under NEA conditions. We suggest that NEA is associated with an altered ability to bind one stimulus to another as a result of impaired recollection, resulting in poorer associative memory performance. The current study findings may contribute to the understanding of the mechanism underlying memory impairments reported in disorders associated with traumatic stress.
Murray, Alexandra M; Nobre, Anna C; Stokes, Mark G
Visual short-term memory (VSTM) is limited in capacity. Therefore, it is important to encode only visual information that is most likely to be relevant to behaviour. Here we asked which aspects of selective biasing of VSTM encoding predict subsequent memory-based performance. We measured EEG during a selective VSTM encoding task, in which we varied parametrically the memory load and the precision of recall required to compare a remembered item to a subsequent probe item. On half the trials, a spatial cue indicated that participants only needed to encode items from one hemifield. We observed a typical sequence of markers of anticipatory spatial attention: early attention directing negativity (EDAN), anterior attention directing negativity (ADAN), late directing attention positivity (LDAP); as well as of VSTM maintenance: contralateral delay activity (CDA). We found that individual differences in preparatory brain activity (EDAN/ADAN) predicted cue-related changes in recall accuracy, indexed by memory-probe discrimination sensitivity (d'). Importantly, our parametric manipulation of memory-probe similarity also allowed us to model the behavioural data for each participant, providing estimates for the quality of the memory representation and the probability that an item could be retrieved. We found that selective encoding primarily increased the probability of accurate memory recall; that ERP markers of preparatory attention predicted the cue-related changes in recall probability. Copyright © 2011. Published by Elsevier Ltd.
McNeil, Jessica; Cameron, Jameason D; Finlayson, Graham; Blundell, John E; Doucet, Éric
Increases in energy, lipid and carbohydrate intakes during the luteal phase have been previously observed. However, it is not known whether this is due to phase-dependent variations in the reward value of certain foods. Moreover, increases in olfactory sensitivity have been proposed and may be involved in these changes in food reward. Therefore, we examined olfactory performance and the reward value of foods varying in fat content and taste. Seventeen women (Body mass index: 22.3±1.6 kg/m(2); Body fat-DXA: 28.5±6.8%) were recruited to participate in 3 identical sessions, performed during distinct phases of the menstrual cycle - early follicular/menstruation, late follicular/ovulation and mid-luteal - verified by plasma sex-steroid hormones and oral temperature. Food preference, implicit wanting, and explicit wanting and liking for visual food cues, varying in fat content and taste, were measured with a validated experimental platform involving a forced choice computer task. Odour threshold, odour discrimination, odour identification and total odour scores were measured using odourized pens. Ad libitum energy and macronutrient intake was measured with a validated food menu. Results showed greater total odour scores (pfoods (pfoods. Copyright © 2013 Elsevier Inc. All rights reserved.
Filbey, Francesca M; McQueeny, Tim; Kadamangudi, Shrinath; Bice, Collette; Ketcherside, Ariel
Combined use of marijuana (MJ) and tobacco is highly prevalent in today's population. Individual use of either substance is linked to structural brain changes and altered cognitive function, especially with consistent reports of hippocampal volume deficits and poorer memory performance. However, the combined effects of MJ and tobacco on hippocampal structure and on learning and memory processes remain unknown. In this study, we examined both the individual and combined effects of MJ and tobacco on hippocampal volumes and memory performance in four groups of adults taken from two larger studies: MJ-only users (n=36), nicotine-only (Nic-only, n=19), combined marijuana and nicotine users (MJ+Nic, n=19) and non-using healthy controls (n=16). Total bilateral hippocampal volumes and memory performance (WMS-III logical memory) were compared across groups controlling for total brain size and recent alcohol use. Results found MJ and MJ+Nic groups had smaller total hippocampal volumes compared to Nic-only and controls. No significant difference between groups was found between immediate and delayed story recall. However, the controls showed a trend for larger hippocampal volumes being associated with better memory scores, while MJ+Nic users showed a unique inversion, whereby smaller hippocampal volume was associated with better memory. Overall, results suggest abnormalities in the brain-behavior relationships underlying memory processes with combined use of marijuana and nicotine use. Further research will need to address these complex interactions between MJ and nicotine. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.
Jiang, Cunmei; Lim, Vanessa K; Wang, Hang; Hamm, Jeff P
Music processing is influenced by pitch perception and memory. Additionally these features interact, with pitch memory performance decreasing as the perceived distance between two pitches decreases. This study examined whether or not the difficulty of pitch discrimination influences pitch retention by testing individuals with congenital amusia. Pitch discrimination difficulty was equated by determining an individual's threshold with a two down one up staircase procedure and using this to create conditions where two pitches (the standard and the comparison tones) differed by 1x, 2x, and 3x the threshold setting. For comparison with the literature a condition that employed a constant pitch difference of four semitones was also included. The results showed that pitch memory performance improved as the discrimination between the standard and the comparison tones was made easier for both amusic and control groups, and more importantly, that amusics did not show any pitch retention deficits when the discrimination difficulty was equated. In contrast, consistent with previous literature, amusics performed worse than controls when the physical pitch distance was held constant at four semitones. This impaired performance has been interpreted as evidence for pitch memory impairment in the past. However, employing a constant pitch distance always makes the difference closer to the discrimination threshold for the amusic group than for the control group. Therefore, reduced performance in this condition may simply reflect differences in the perceptual difficulty of the discrimination. The findings indicate the importance of equating the discrimination difficulty when investigating memory.
Lye, T.C.; Creasey, H.; Kril, J.J. [University of Sydney and Concord Hospital, Centre for Education and Research on Ageing, Sydney, New South Wales (Australia); Grayson, D.A. [University of Sydney, School of Psychology, Sydney (Australia); Piguet, O. [University of Sydney and Concord Hospital, Centre for Education and Research on Ageing, Sydney, New South Wales (Australia); Prince of Wales Medical Research Institute and the University of New South Wales, Sydney (Australia); Bennett, H.P. [Prince of Wales Medical Research Institute and the University of New South Wales, Sydney (Australia); Ridley, L.J. [Concord Hospital, Department of Radiology, Sydney (Australia); Broe, G.A. [Prince of Wales Medical Research Institute and the University of New South Wales, Sydney (Australia); Prince of Wales Hospital, Sydney (Australia)
A number of different methods have been employed to correct hippocampal volumes for individual variation in head size. Researchers have previously used qualitative visual inspection to gauge hippocampal atrophy. The purpose of this study was to determine the best measure(s) of hippocampal size for predicting memory functioning in 102 community-dwelling individuals over 80 years of age. Hippocampal size was estimated using magnetic resonance imaging (MRI) volumetry and qualitative visual assessment. Right and left hippocampal volumes were adjusted by three different estimates of head size: total intracranial volume (TICV), whole-brain volume including ventricles (WB+V) and a more refined measure of whole-brain volume with ventricles extracted (WB). We compared the relative efficacy of these three volumetric adjustment methods and visual ratings of hippocampal size in predicting memory performance using linear regression. All four measures of hippocampal size were significant predictors of memory performance. TICV-adjusted volumes performed most poorly in accounting for variance in memory scores. Hippocampal volumes adjusted by either measure of whole-brain volume performed equally well, although qualitative visual ratings of the hippocampus were at least as effective as the volumetric measures in predicting memory performance in community-dwelling individuals in the ninth or tenth decade of life. (orig.)
Allen, Mark S; Laborde, Sylvain; Walter, Emma E
This prospective study explored the potential mediating role of health-related behavior (alcohol involvement, diet, television viewing, and physical activity) in the association between personality and change in memory performance over 2 years. A nationally representative sample of 8,376 U.K. participants aged 55 years and older (4,572 women, 3,804 men) completed self-report measures of personality and health-related behavior in 2010, and completed a memory performance task in 2010 and 2012. After removing variance associated with potential confounding variables, neuroticism and agreeableness had negative associations, and openness and conscientiousness positive associations with change in memory performance. There were no moderation effects by age, sex, education level, or ethnicity. Multiple mediator models demonstrated that physical activity, television viewing, and alcohol intake mediated associations between personality and change in memory performance. These findings provide evidence that the association between personality and memory performance in older adults can be explained, in part, through health-related behavior.
Full Text Available Music processing is influenced by pitch perception and memory. Additionally these features interact, with pitch memory performance decreasing as the perceived distance between two pitches decreases. This study examined whether or not the difficulty of pitch discrimination influences pitch retention by testing individuals with congenital amusia. Pitch discrimination difficulty was equated by determining an individual's threshold with a two down one up staircase procedure and using this to create conditions where two pitches (the standard and the comparison tones differed by 1x, 2x, and 3x the threshold setting. For comparison with the literature a condition that employed a constant pitch difference of four semitones was also included. The results showed that pitch memory performance improved as the discrimination between the standard and the comparison tones was made easier for both amusic and control groups, and more importantly, that amusics did not show any pitch retention deficits when the discrimination difficulty was equated. In contrast, consistent with previous literature, amusics performed worse than controls when the physical pitch distance was held constant at four semitones. This impaired performance has been interpreted as evidence for pitch memory impairment in the past. However, employing a constant pitch distance always makes the difference closer to the discrimination threshold for the amusic group than for the control group. Therefore, reduced performance in this condition may simply reflect differences in the perceptual difficulty of the discrimination. The findings indicate the importance of equating the discrimination difficulty when investigating memory.
McDougall, Graham J; Mackert, Michael; Becker, Heather
Health literacy is associated with cognitive function across multiple domains in older adults, and these older adults may face special memory and cognitive challenges that can limit their health literacy and, in turn, their ability to live independently. The aim of this study was to evaluate if an association existed among health literacy, memory performance, and performance-based functional ability in community-residing older adults. Forty-five adults participated in this study. Designed to reflect everyday memory, the Rivermead Behavioral Memory Test (RBMT) bridges laboratory-based measures of memory and assessments obtained by self-report and observation. The RBMT classifies individuals into four categories of memory performance: normal, poor, mildly impaired, and severely impaired. The participants were recruited in the two categories of normal (≥22) or impaired (≤16) category on the RBMT. The sample consisted of 14 who were in the impaired category and 31 in the normal group. Their average age was 77.11 years, and their average number of years of education was 15.33 years. Health literacy scores measured with the Rapid Estimate of Adult Literacy in Medicine. Health literacy scores were high (M = 65.09, SD = 2.80). Thirty-four participants or 76% of the sample scored a 66 out of a possible score of 80. Pearson correlations were calculated for the study variables. Health literacy scores with education and cognition (.30), memory performance groups (normal vs. poor; .25), and performance-based instrumental activities (.50) were associated significantly. The development of a broader assortment of health literacy instruments would improve the ability of researchers to both compare studies and build on the knowledge and results of others.
Kessels, Roy P C; Remmerswaal, Madieke; Wilson, Barbara A
Although patients with Alzheimer dementia (AD) have impaired explicit memory, more automatic, implicit aspects of learning and memory may be relatively preserved. However, neuropsychological tests for the assessment of implicit memory are lacking. This study examines a newly developed test, the Implicit Memory Test, in 28 patients with severe AD (mini-mental state examination 5 to 12) and 22 cognitively unimpaired matched controls (mini-mental state examination 25 to 29). The Implicit Memory Test consists of visually presented word (stem-completion) and picture (fragmented picture identification) subtests, each comprising 3 learning trials and a delayed test. Explicit memory was also assessed, using the verbal paired-associate learning subtest from the Wechsler Memory Scale and the Visual Association Test. Patients with AD obtained a floor performance on both explicit memory tests, whereas a significant learning curve was found for both the stem-completion and the fragmented pictures subtests of the Implicit Memory Test. Delayed testing on the fragmented pictures subtest showed a preserved performance that may have been mediated by implicit learning. Delayed performance on the stem-completion subtest, however, showed clear memory decay that suggests contamination by explicit memory function, at least in the controls. These findings extend the earlier results on word-stem completion and fragmented picture identification in patients with mild-to-moderate AD and indicate that residual learning capacity can be assessed in severe AD.
Almela, M.; Hidalgo, V.; van der Meij, L.; Villada, C.; Pulopulos, M. M.; Salvador, A.
Age-related memory decline has been associated with a faulty regulation of the hypothalamus-pituitary-adrenal axis (HPA-axis). The aim of this study was to investigate whether the magnitude of the stress-induced cortisol increase is related to memory performance when memory is measured in
Kliegel, Matthias; Jager, Theodor
The present study investigated event-based prospective memory in five age groups of preschoolers (i.e., 2-, 3-, 4-, 5-, and 6-year-olds). Applying a laboratory-controlled prospective memory procedure, the data showed that event-based prospective memory performance improves across the preschool years, at least between 3 and 6 years of age. However,…
Greneche, Jerome; Krieger, Jean; Bertrand, Frederic; Erhardt, Christine; Maumy, Myriam; Tassi, Patricia
Both working and immediate memories were assessed every 4 h by specific short-term memory tasks over sustained wakefulness in 12 patients with obstructive sleep apnea and hypopnea syndrome (OSAHS) and 10 healthy controls. Results indicated that OSAHS patients exhibited lower working memory performances than controls on both backward digit span and…
Greenwood, Pamela M.; Sundararajan, Ramya; Lin, Ming-Kuan; Kumar, Reshma; Fryxell, Karl J.; Parasuraman, Raja
We investigated the relation between the two systems of visuospatial attention and working memory by examining the effect of normal variation in cholinergic and noradrenergic genes on working memory performance under attentional manipulation. We previously reported that working memory for location was impaired following large location precues,…
Goghari, Vina M; MacDonald, Angus W; Sponheim, Scott R
Diffuse structural abnormalities in the prefrontal cortex have been reported in both schizophrenia patients and their nonpsychotic biological relatives. Additionally, working memory difficulties have long been documented in schizophrenia patients and have been associated with the genetic liability for the disorder. The present analysis investigated the relationship between prefrontal regional grey matter volumes and two facets of working memory in schizophrenia using a family study. Structural neuroimaging scans provided measurements of rostral middle, superior, and inferior prefrontal cortical grey matter volumes. Participants also completed a spatial working memory task that measured both short-term maintenance and manipulation of material in memory. Both schizophrenia patients and relatives had reduced superior and inferior frontal grey matter volumes. Schizophrenia patients demonstrated a spatial working memory deficit compared to both controls and relatives, with no greater impairment when required to manipulate material. Smaller prefrontal volumes in schizophrenia patients were associated with worse working memory performance. These relationships were absent in the nonpsychotic relatives and controls. Despite normative behavioural performance, nonpsychotic relatives demonstrated abnormalities in brain structure similar to those found in schizophrenia patients. Manipulation abilities were not more impaired than maintenance in schizophrenia patients. Consistent with other neuroimaging research, our results suggest that direct measures of the underlying biology may be more sensitive to the effects of the genetic liability for schizophrenia than behavioural measures. PMID:24529364
Smeets, T; Jelicic, M; Merckelbach, H; Peters, M; Fett, A; Taverniers, J; Henquet, C; Dautzenberg, J
Research on the effect of acute stress and high levels of glucocorticoids on memory has largely focused on memory tasks involving the medial temporal lobe (e.g., declarative memory). Less is known, however, about the effects of stress and glucocorticoids on more strategic memory processes regulated by the prefrontal cortex (e.g., source monitoring). In the current study, the authors investigated whether exposure to acute psychosocial stress would result in altered source monitoring performance relative to the performance of a nonstressed control group. To this end, the authors assigned nonsmoking, healthy, young men to either a stress (n = 22) or a control (n = 18) condition, after which the men were given an internal source monitoring test. Results show that relative to control participants, stressed participants made fewer source monitoring errors. This study suggests that stress may have differential effects on memory, depending on whether the memory test is regulated by the prefrontal cortex or the medial temporal lobe. 2006 APA, all rights reserved
The Structured Memory Access (SMS) architecture implementation presented in this thesis is formulated with the intention of alleviating two well-known inefficiencies that exist in current scalar computer architectures: address generation overhead and memory bandwidth utilization. Furthermore, the SMA architecture introduces an additional level of parallelism which is not present in current pipelined supercomputers, namely, overlapped execution of the access process and execute process on two distinct special-purpose, asynchronously-coupled processors. Each processor executes a separate instruction stream to perform its specific task which, together, are functionally equivalent in a conventional program. Our simulation results show that, for typical numerical programs, the access processor (MAP) is capable of achieving slip, i.e., running sufficiently ahead of the execute processor (CP) so that operand fetch requests for data items required by the CP are issued early enough and rapidly enough for the CP rarely to experience any memory access wait time. In this manner the SMA tolerates long memory access time, albeit high bandwidth, paths to memory without sacrificing performance. Speedups relative to the Cray-1 in scalar mode often exceed two, due to dual processing and reductions in memory wait time. 17 refs., 11 figs., 3 tabs.
Marquez de la Plata, C; Lacritz, L H; Mitschke, R; Van Ness, P; Agostini, M; Diaz-Arrastia, R; Cullum, C M
There is relatively little research pertaining to neuropsychological assessment of Spanish-speaking individuals with intractable temporal lobe epilepsy (TLE). The current study examined verbal and visual memory performances in 38 primarily Spanish-speaking patients with TLE (Right = 15, Left = 23) of similar epilepsy duration to determine if lateralizing differences can be found using verbal and nonverbal memory tests. On a test specifically designed to assess auditory learning and memory among Spanish-speaking individuals, the Spanish Verbal Learning Test (SVLT), patients with left TLE performed significantly worse than patients with right TLE. In contrast, no significant differences in story or visual memory were seen using common memory tests translated into Spanish. Similar to what has been found in English speakers, these results show that verbal memory differences can be seen between left and right sided TLE patients who are Spanish-speaking to aid in providing lateralizing information; however, these differences may be best detected using tests developed for and standardized on Spanish-speaking patients.
Vecchio, F; Miraglia, F; Quaranta, D; Granata, G; Romanello, R; Marra, C; Bramanti, P; Rossini, P M
Functional brain abnormalities including memory loss are found to be associated with pathological changes in connectivity and network neural structures. Alzheimer's disease (AD) interferes with memory formation from the molecular level, to synaptic functions and neural networks organization. Here, we determined whether brain connectivity of resting-state networks correlate with memory in patients affected by AD and in subjects with mild cognitive impairment (MCI). One hundred and forty-four subjects were recruited: 70 AD (MMSE Mini Mental State Evaluation 21.4), 50 MCI (MMSE 25.2) and 24 healthy subjects (MMSE 29.8). Undirected and weighted cortical brain network was built to evaluate graph core measures to obtain Small World parameters. eLORETA lagged linear connectivity as extracted by electroencephalogram (EEG) signals was used to weight the network. A high statistical correlation between Small World and memory performance was found. Namely, higher Small World characteristic in EEG gamma frequency band during the resting state, better performance in short-term memory as evaluated by the digit span tests. Such Small World pattern might represent a biomarker of working memory impairment in older people both in physiological and pathological conditions. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.
Injoque-Ricle, Irene; Barreyro, Juan Pablo; Formoso, Jesica; Jaichenco, Virginia I
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.
Gilchrist, Amanda L; Duarte, Audrey; Verhaeghen, Paul
Research with younger adults has shown that retrospective cues can be used to orient top-down attention toward relevant items in working memory. We examined whether older adults could take advantage of these cues to improve memory performance. Younger and older adults were presented with visual arrays of five colored shapes; during maintenance, participants were presented either with an informative cue based on an object feature (here, object shape or color) that would be probed, or with an uninformative, neutral cue. Although older adults were less accurate overall, both age groups benefited from the presentation of an informative, feature-based cue relative to a neutral cue. Surprisingly, we also observed differences in the effectiveness of shape versus color cues and their effects upon post-cue memory load. These results suggest that older adults can use top-down attention to remove irrelevant items from visual working memory, provided that task-relevant features function as cues.
Pottage, Claire L; Schaefer, Alexandre
The emotional enhancement of memory is often thought to be determined by attention. However, recent evidence using divided attention paradigms suggests that attention does not play a significant role in the formation of memories for aversive pictures. We report a study that investigated this question using a paradigm in which participants had to encode lists of randomly intermixed negative and neutral pictures under conditions of full attention and divided attention followed by a free recall test. Attention was divided by a highly demanding concurrent task tapping visual processing resources. Results showed that the advantage in recall for aversive pictures was still present in the DA condition. However, mediation analyses also revealed that concurrent task performance significantly mediated the emotional enhancement of memory under divided attention. This finding suggests that visual attentional processes play a significant role in the formation of emotional memories. PsycINFO Database Record (c) 2012 APA, all rights reserved
Zinke, K.; Altgassen, A.M.; Mackinlay, R,J,; Rizzo, P.; Drechsler, R.; Kliegel, M.
The current study investigated prospective memory (PM) performance in children with attention deficit/hyperactivity disorder (ADHD) and controls and aimed at exploring possible underlying factors of PM performance. Twenty-two children with ADHD and 39 age- and ability-matched typically developing
High-performance non-volatile polymer ferroelectric memory are fabricated on banknotes using poly(vinylidene fluoride trifluoroethylene). The devices show excellent performance with high remnant polarization, low operating voltages, low leakage, high mobility, and long retention times. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Dirk, Judith; Schmiedek, Florian
Children experience good and bad days in their performance. Although this phenomenon is well-known to teachers, parents, and students it has not been investigated empirically. We examined whether children's working memory performance varies systematically from day to day and to which extent fluctuations at faster timescales (i.e., occasions,…
Schnitzspahn, Katharina M.; Stahl, Christoph; Zeintl, Melanie; Kaller, Christoph P.; Kliegel, Matthias
Prospective memory performance shows a decline in late adulthood. The present article examines the role of 3 main executive function facets (i.e., shifting, updating, and inhibition) as possible developmental mechanisms associated with these age effects. One hundred seventy-five young and 110 older adults performed a battery of cognitive tests…
Huang, Tracy; Loft, Shayne; Humphreys, Michael S.
"Time-based prospective memory" (PM) refers to performing intended actions at a future time. Participants with time-based PM tasks can be slower to perform ongoing tasks (costs) than participants without PM tasks because internal control is required to maintain the PM intention or to make prospective-timing estimates. However, external…
Osman, Homira; Sullivan, Jessica R.
Purpose: The objectives of this study were to determine (a) whether school-age children with typical hearing demonstrate poorer auditory working memory performance in multitalker babble at degraded signal-to-noise ratios than in quiet; and (b) whether the amount of cognitive demand of the task contributed to differences in performance in noise. It…
Schouten, Eveline A.; Schiemanck, Sven K.; Brand, Nico; Post, Marcel W. M.
We investigated the relationship between ischemic lesion characteristics (hemispheric side, cortical and subcortical level, volume) and memory performance, 1 year after stroke. Verbal and visual memory of 86 patients with stroke were assessed with Rey Auditory-Verbal Learning Test and the Doors
Full Text Available The present study aimed to elucidate the neuro-cognitive processes underlying age-related differences in working memory. Young and middle-aged participants performed a two-choice task with low and a 2-back task with high working memory load. The P300, an event-related potential reflecting controlled stimulus-response processing in working memory, and the underlying neuronal sources of expected age-related differences were analyzed using sLORETA. Response speed was generally slower for the middle-aged than the young group. Under low working memory load the middle-aged participants traded speed for accuracy. The middle-aged were less efficient in the 2-back task as they responded slower while the error rates did not differ for groups. An age-related decline of the P300 amplitude and characteristic topographical differences were especially evident in the 2-back task. A more detailed analysis of the P300 in non-target trials revealed that amplitudes in the young but not middle-aged group differentiate between correctly detected vs. missed targets in the following trial. For these trials, source analysis revealed higher activation for the young vs. middle-aged group in brain areas which support working memory processes. The relationship between P300 and overt performance was validated by significant correlations. To sum up, under high working memory load the young group showed an increased neuronal activity before a successful detected target, while the middle-aged group showed the same neuronal pattern regardless of whether a subsequent target will be detected or missed. This stable memory trace before detected targets was reflected by a specific activation enhancement in brain areas which orchestrate maintenance, update, storage and retrieval of information in working memory.
Vingerhoets, G; Miatton, M; Vonck, K; Seurinck, R; Boon, P
We investigated the relationship between material-specific memory performance elicited during the Wada test, or intracarotid amobarbital procedure (IAP), and classic neuropsychological assessment in 89 surgical candidates with refractory medial temporal lobe epilepsy (MTLE). The neuropsychological battery included measures of simple and complex verbal and visual memory, whereas the IAP material consisted of verbal and dually encodable stimuli. Neuropsychological testing revealed that reduced verbal memory performance was associated with left-sided MTLE, whereas visual memory tasks revealed no differences between patients with left-sided and right-sided MTLE. During IAP, memory performance was worse with the ipsilesional hemisphere, regardless of lesion side. Most importantly, performance on verbal memory tests was significantly, but moderately, correlated with left hemispheric IAP performance, indicating that memory tasks using verbal material are a valid marker of left hemispheric integrity in left language-dominant MTLE patients and significantly predict left hemispheric memory performance during IAP. In contrast, performance on classic visual memory tests is unrelated to right hemispheric IAP performance, suggesting that the currently used visual memory stimuli do not reflect right hemispheric sensitivity.
Duncko, Roman; Johnson, Linda; Merikangas, Kathleen; Grillon, Christian
Effects of acute stress exposure on learning and memory have been frequently studied in both animals and humans. However, only a few studies have focused specifically on working memory performance and the available data are equivocal. The present study examined working memory performance during the Sternberg item recognition task after exposure to a predominantly adrenergic stressor. Twenty four healthy subjects were randomly assigned to a stress group or a control group. The stress group was exposed to the cold pressor stress test (CPS; i.e. insertion of the dominant hand into ice water for 60s),while 37 degrees C warm water was used with the control group. Twenty minutes after the stress exposure, working memory performance was tested with the Sternberg item recognition task with three levels of cognitive load. Sympathetic nervous system and hypothalamic pituitary adrenocortical (HPA) axis activation during CPS, were assessed by measuring heart rate and salivary cortisol before and during (heart rate) or 30 min after (cortisol) the stress procedure. Exposure to the CPS test was associated with a significant increase in heart rate but no increase in salivary cortisol. Participants exposed to the stress procedure showed significantly shorter reaction times during trials with higher cognitive load but tended to show higher false alarm rates than control subjects. The present results indicate that exposure to CPS can be associated with signs of both enhanced and impaired working memory performance. The observed behavioral pattern might represent a form of streamlined information processing advantageous in a threatening situation.
Full Text Available Background Some studies have shown working memory impairment following stressful situations. Also, researchers have found that working memory performance depends on many different factors such as emotional load of stimuli and gender. Objectives The present study aimed to determine the effects of stress induction on visual working memory (VWM performance among female and male university students. Methods This quasi-experimental research employed a posttest with only control group design (within-group study. A total of 62 university students (32 males and 30 females were randomly selected and allocated to experimental and control groups (mean age of 23.73. Using cold presser test (CPT, stress was induced and then, an n-back task was implemented to evaluate visual working memory function (such as the number of true items, time reactions, and the number of wrong items through emotional and non-emotional pictures. 100 pictures were selected from the international affective picture system (IASP with different valences. Results Results showed that stress impaired different visual working memory functions (P < 0.002 for true scores, P < 0.001 for reaction time, and P < 0.002 for wrong items. Conclusions In general, stress significantly decreases the VWM performances. On the one hand, females were strongly impressed by stress more than males and on the other hand, the VWM performance was better for emotional stimuli than non-emotional stimuli.
Full Text Available This study examined language proficiency and age of language acquisition influences on working memory performance in bilinguals. Bilingual subjects were administered reading span task in parallel versions for their first and second language. In Experiment 1, language proficiency effect was tested by examination of low and highly proficient second language speakers. In Experiment 2, age of language acquisition was examined by comparing the performance of proficient second language speakers who acquired second language either early or later in their lives. Both proficiency and age of language acquisition were found to affect bilingual working memory performance, and the proficiency effect was observed even at very high levels of language competence. The results support the notion of working memory as a domain that is influenced both by a general pool of resources and certain domain specific factors.
Hubbard, Kurt K; Blyler, Diane
Research involving working memory has indicated that stress and anxiety compete for attentional resources when a person engages in attention-dependent cognitive processing. The purpose of this study was to investigate the impact of perceived stress and state anxiety on working memory and academic performance among health science students and to explore whether the reduction of stress and anxiety was achieved through progressive muscle relaxation (PMR) training. A convenience sample of 128 graduate students participated in this study. Using an experimental pretest-posttest design, we randomly assigned participants to a PMR group or a control group. Results indicated that PMR reduced state anxiety, F(1, 126) = 15.58, p academic performance in the treatment group. The results of this study contribute to the literature on Attentional Control Theory by clarifying the process through which working memory and anxiety affect cognitive performance. Copyright © 2016 by the American Occupational Therapy Association, Inc.
Recent research suggests that chewing gum may increase alertness and lead to changes in cognitive performance. The present study examined effects of chewing gum on these functions within the context of a single study. This study had four main aims. The first was to examine whether chewing gum improved learning and memory of information in a story. The second aim was to determine whether chewing gum improved test performance on a validated intellectual task (the Alice Heim task). A third aim was to determine whether chewing gum improved performance on short memory tasks (immediate and delayed recall of a list of words, delayed recognition memory, retrieval from semantic memory, and a working memory task). The final aim was to determine whether chewing gum improved mood (alertness, calm and hedonic tone). A cross-over design was used with gum and no-gum sessions being on consecutive weeks. In each week, volunteers attended for two sessions, two days apart. The first session assessed mood, immediate recall of information from a story and performance on short memory tasks. The second session assessed mood, delayed recall of information from a story and performance of an intelligence test (the Alice Heim test). There were no significant effects of chewing gum on any aspect of recall of the story. Chewing gum improved the accuracy of performing the Alice Heim test which confirms the benefits of gum on test performance seen in an earlier study. Chewing gum had no significant effect on the short memory tasks. Chewing gum increased alertness at the end of the test session in both parts of the study. This effect was in the region of a 10% increase and was highly significant (P < 0.001). The results of this study showed that chewing gum increases alertness. In contrast, no significant effects of chewing gum were observed in the memory tasks. Intellectual performance was improved in the gum condition. Overall, the results suggest further research on the alerting effects of
Moisala, M; Salmela, V; Hietajärvi, L; Carlson, S; Vuontela, V; Lonka, K; Hakkarainen, K; Salmela-Aro, K; Alho, K
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 using functional magnetic resonance imaging (fMRI). The results revealed that the extent of daily gaming activity was related to enhancements in both performance accuracy and speed during the most demanding (2-back) level of the working memory task. This improved working memory performance was accompanied by enhanced recruitment of a fronto-parietal cortical network, especially the dorsolateral prefrontal cortex. In contrast, during the less demanding (1-back) level of the task, gaming was associated with decreased activity in the same cortical regions. Our results suggest that a greater degree of daily gaming experience is associated with better working memory functioning and task difficulty-dependent modulation in fronto-parietal brain activity already in adolescence and even when non-expert gamers are studied. The direction of causality within this association cannot be inferred with certainty due to the correlational nature of the current study. Copyright © 2016 Elsevier B.V. All rights reserved.
McKendrick, Ryan; Ayaz, Hasan; Olmstead, Ryan; Parasuraman, Raja
To better understand the mechanisms by which working memory training can augment human performance we continuously monitored trainees with near infrared spectroscopy (NIRS) while they performed a dual verbal-spatial working memory task. Linear mixed effects models were used to model the changes in cerebral hemodynamic response as a result of time spent training working memory. Nonlinear increases in left dorsolateral prefrontal cortex (DLPFC) and right ventrolateral prefrontal cortex (VLPFC) were observed with increased exposure to working memory training. Adaptive and yoked training groups also showed differential effects in rostral prefrontal cortex with increased exposure to working memory training. There was also a significant negative relationship between verbal working memory performance and bilateral VLPFC activation. These results are interpreted in terms of decreased proactive interference, increased neural efficiency, reduced mental workload for stimulus processing, and increased working memory capacity with training. Copyright © 2013 Elsevier Inc. All rights reserved.
Gour, Natalina; Ranjeva, Jean-Philippe; Ceccaldi, Mathieu; Confort-Gouny, Sylviane; Barbeau, Emmanuel; Soulier, Elisabeth; Guye, Maxime; Didic, Mira; Felician, Olivier
Spontaneous fluctuations in the blood oxygenation level-dependent (BOLD) signal, as measured by functional magnetic resonance imaging (fMRI) at rest, exhibit a temporally coherent activity thought to reflect functionally relevant networks. Antero-mesial temporal structures are the site of early pathological changes in Alzheimer's disease and have been shown to be critical for declarative memory. Our study aimed at exploring the functional impact of basal connectivity of an anterior temporal network (ATN) on declarative memory. A heterogeneous group of subjects with varying performance on tasks assessing memory was therefore selected, including healthy subjects and patients with isolated memory complaint, amnestic Mild Cognitive Impairment (aMCI) and mild Alzheimer's disease (AD). Using Independent Component Analysis on resting-state fMRI, we extracted a relevant anterior temporal network (ATN) composed of the perirhinal and entorhinal cortex, the hippocampal head, the amygdala and the lateral temporal cortex extending to the temporal pole. A default mode network and an executive-control network were also selected to serve as control networks. We first compared basal functional connectivity of the ATN between patients and control subjects. Relative to controls, patients exhibited significantly increased functional connectivity in the ATN during rest. Specifically, voxel-based analysis revealed an increase within the inferior and superior temporal gyrus and the uncus. In the patient group, positive correlations between averaged connectivity values of ATN and performance on anterograde and retrograde object-based memory tasks were observed, while no correlation was found with other evaluated cognitive measures. These correlations were specific to the ATN, as no correlation between performance on memory tasks and the other selected networks was found. Taken together, these findings provide evidence that basal connectivity inside the ATN network has a functional role in
Jung, Ji Hyung; Kim, Sunghwan; Kim, Hyeonjung; Park, Jongnam; Oh, Joon Hak
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. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Hedman, L; Klingberg, T; Enochsson, L; Kjellin, A; Felländer-Tsai, L
This study addresses for the first time the relationship between working memory and performance measures in image-guided instrument navigation with Minimally Invasive Surgical Trainer-Virtual Reality (MIST-VR) and GI Mentor II (a simulator for gastroendoscopy). In light of recent research on simulator training, it is now prime time to ask why in a search for mechanisms rather than show repeatedly that conventional curriculum for simulation training has effect. The participants in this study were 28 Swedish medical students taking their course in basic surgery. Visual and verbal working memory span scores were assessed by a validated computer program (RoboMemo) and correlated with visual-spatial ability (MRT-A test), total flow experience (flow scale), mental strain (Borg scale), and performance scores in manipulation and diathermy (MD) using Procedicus MIST-VR and GI Mentor 11 (exercises 1 and 3). Significant Pearson's r correlations were obtained between visual working memory span scores for visual data link (a RoboMemo exercise) and movement economy (r = -0.417; p memory span scores in rotating data link (another RoboMemo exercise) and both total time (r = -0.467; p memory for surgical novices may be important for performance in virtual simulator training with two well-known and validated simulators.
Jones, Gary; Macken, Bill
Studies using tests such as digit span and nonword repetition have implicated short-term memory across a range of developmental domains. Such tests ostensibly assess specialized processes for the short-term manipulation and maintenance of information that are often argued to enable long-term learning. However, there is considerable evidence for an influence of long-term linguistic learning on performance in short-term memory tasks that brings into question the role of a specialized short-term memory system separate from long-term knowledge. Using natural language corpora, we show experimentally and computationally that performance on three widely used measures of short-term memory (digit span, nonword repetition, and sentence recall) can be predicted from simple associative learning operating on the linguistic environment to which a typical child may have been exposed. The findings support the broad view that short-term verbal memory performance reflects the application of long-term language knowledge to the experimental setting.
Manktelow, Anne E; Menon, David K; Sahakian, Barbara J; Stamatakis, Emmanuel A
Traumatic brain injury (TBI) often results in cognitive impairments for patients. The aim of this proof of concept study was to establish the nature of abnormalities, in terms of activity and connectivity, in the working memory network of TBI patients and how these relate to compromised behavioral outcomes. Further, this study examined the neural correlates of working memory improvement following the administration of methylphenidate. We report behavioral, functional and structural MRI data from a group of 15 Healthy Controls (HC) and a group of 15 TBI patients, acquired during the execution of the N-back task. The patients were studied on two occasions after the administration of either placebo or 30 mg of methylphenidate. Between group tests revealed a significant difference in performance when HCs were compared to TBI patients on placebo [F(1, 28) = 4.426, p working memory network and (b) Methylphenidate improves the cognitive outcomes on a working memory task. Therefore, we conclude that methylphenidate may render the working memory network in a TBI group more consistent with that of an intact working memory network.
Oedekoven, Christiane S H; Jansen, Andreas; Keidel, James L; Kircher, Tilo; Leube, Dirk
Associative memory is essential to everyday activities, such as the binding of faces and corresponding names to form single bits of information. However, this ability often becomes impaired with increasing age. The most important neural substrate of associative memory is the hippocampus, a structure crucially implicated in the pathogenesis of Alzheimer's disease (AD). The main aim of this study was to compare neural correlates of associative memory in healthy aging and mild cognitive impairment (MCI), an at-risk state for AD. We used fMRI to investigate differences in brain activation and connectivity between young controls (n = 20), elderly controls (n = 32) and MCI patients (n = 21) during associative memory retrieval. We observed lower hippocampal activation in MCI patients than control groups during a face-name recognition task, and the magnitude of this decrement was correlated with lower associative memory performance. Further, increased activation in precentral regions in all older adults indicated a stronger involvement of the task positive network (TPN) with age. Finally, functional connectivity analysis revealed a stronger link of hippocampal and striatal components in older adults in comparison to young controls, regardless of memory impairment. In elderly controls, this went hand-in-hand with a stronger activation of striatal areas. Increased TPN activation may be linked to greater reliance on cognitive control in both older groups, while increased functional connectivity between the hippocampus and the striatum may suggest dedifferentiation, especially in elderly controls.
Manktelow, Anne E.; Menon, David K.; Sahakian, Barbara J.; Stamatakis, Emmanuel A.
Traumatic brain injury (TBI) often results in cognitive impairments for patients. The aim of this proof of concept study was to establish the nature of abnormalities, in terms of activity and connectivity, in the working memory network of TBI patients and how these relate to compromised behavioral outcomes. Further, this study examined the neural correlates of working memory improvement following the administration of methylphenidate. We report behavioral, functional and structural MRI data from a group of 15 Healthy Controls (HC) and a group of 15 TBI patients, acquired during the execution of the N-back task. The patients were studied on two occasions after the administration of either placebo or 30 mg of methylphenidate. Between group tests revealed a significant difference in performance when HCs were compared to TBI patients on placebo [F(1, 28) = 4.426, p memory network and (b) Methylphenidate improves the cognitive outcomes on a working memory task. Therefore, we conclude that methylphenidate may render the working memory network in a TBI group more consistent with that of an intact working memory network. PMID:28424597
Przybylski, Steven A
An authoritative book for hardware and software designers. Caches are by far the simplest and most effective mechanism for improving computer performance. This innovative book exposes the characteristics of performance-optimal single and multi-level cache hierarchies by approaching the cache design process through the novel perspective of minimizing execution times. It presents useful data on the relative performance of a wide spectrum of machines and offers empirical and analytical evaluations of the underlying phenomena. This book will help computer professionals appreciate the impact of ca
Li, Xianchun; Cheng, Xiaojun; Li, Jiaying; Pan, Yafeng; Hu, Yi; Ku, Yixuan
Previous studies have shown enhanced memory performance resulting from extensive action video game playing. The mechanisms underlying the cognitive benefit were investigated in the current study. We presented two types of retro-cues, with variable intervals to memory array (Task 1) or test array (Task 2), during the retention interval in a change detection task. In Task 1, action video game players demonstrated steady performance while non-action video game players showed decreased performance as cues occurred later, indicating their performance difference increased as the cue-to-memory-array intervals became longer. In Task 2, both participant groups increased their performance at similar rates as cues presented later, implying the performance difference in two groups were irrespective of the test-array-to-cue intervals. These findings suggested that memory benefit from game plays is not attributable to the higher ability of overcoming interference from the test array, but to the interactions between the two processes of protection from decay and resistance from interference, or from alternative hypotheses. Implications for future studies were discussed.
Huiberts, L M; Smolders, K C H J; de Kort, Y A W
This study examined whether diurnal non-image forming (NIF) effects of illuminance level on cognitive task performance depend on task difficulty and time of day. We employed a balanced crossover design with two 60-min sessions of 200 vs. 1000 lux at eye level. Digit-span task difficulty was manipulated within subjects (forward (FDST) vs. backward (BDST) digit-span task), n-back task difficulty was manipulated between subjects (n=1, 2, or 3). Bright light exposure improved FDST performance during the final measurement block, especially in the afternoon. In contrast, BDST performance deteriorated slightly under bright light in the afternoon. Two-back performance was significantly worse under bright light in the afternoon, while no effect of illuminance level was found on 3-back performance. Thus, the more difficult BDST was affected differently by light intensity as compared to the easier FDST. N-back accuracy, however, did not confirm this role of task difficulty. Future studies should investigate whether similar results hold for other types of tasks and how other variables (e.g., time of day, physiological arousal, or other task characteristics) may influence the direction and magnitude of NIF effects on performance. Copyright © 2015 Elsevier B.V. All rights reserved.
Meyerhoff, Hauke S; Huff, Markus
Human long-term memory for visual objects and scenes is tremendous. Here, we test how auditory information contributes to long-term memory performance for realistic scenes. In a total of six experiments, we manipulated the presentation modality (auditory, visual, audio-visual) as well as semantic congruency and temporal synchrony between auditory and visual information of brief filmic clips. Our results show that audio-visual clips generally elicit more accurate memory performance than unimodal clips. This advantage even increases with congruent visual and auditory information. However, violations of audio-visual synchrony hardly have any influence on memory performance. Memory performance remained intact even with a sequential presentation of auditory and visual information, but finally declined when the matching tracks of one scene were presented separately with intervening tracks during learning. With respect to memory performance, our results therefore show that audio-visual integration is sensitive to semantic congruency but remarkably robust against asymmetries between different modalities.
Elmose, Mette; Happé, Francesca
Self-awareness was investigated by assessing accuracy of judging own memory performance in a group of children with autism spectrum disorder (ASD) compared with a group of typically developing (TD) children. Effects of stimulus type (social vs. nonsocial), and availability of feedback information as the task progressed, were examined. Results overall showed comparable levels and patterns of accuracy in the ASD and TD groups. A trend level effect (p = 061, d = 0.60) was found, with ASD participants being more accurate in judging own memory for nonsocial than social stimuli and the opposite pattern for TD participants. These findings suggest that awareness of own memory can be good in children with ASD. It is discussed how this finding may be interpreted, and it is suggested that further investigation into the relation between content, frequency, and quality of self-awareness, and the context of self-awareness, is needed. © 2014 International Society for Autism Research, Wiley Periodicals, Inc.
Giulia De' Lorenzis
Full Text Available The paper analyzes some architectural projects performed in Berlin after the fall of the Wall. All the realizations have had as its object the theme of memory: the Jüdisches Museum by Daniel Libeskind, the Denkmal für die ermordeten Juden Europas of Peter Eisenman and Richard Serra, and the under construction Memorial entitled Bürger in Bewegung of Milla und Partner and Sasha Waltz. In each of the examples, the overcoming of the traditional typical celebratory and explanatory forms of the classically intended monument, has been found in favour of a remembrance idea that, if tends to be more tangible and concrete on one side; on the other introduce, in the same memorial dimension, the most evanescent and nuanced path of the performative experience.
Finney, Steven A; Palmer, Caroline
Research on the effects of context and task on learning and memory has included approaches that emphasize processes during learning (e.g., Craik & Tulving, 1975) and approaches that emphasize a match of conditions during learning with conditions during a later test of memory (e.g., Morris, Bransford, & Franks, 1977; Proteau, 1992; Tulving & Thomson, 1973). We investigated the effects of auditory context on learning and retrieval in three experiments on memorized music performance (a form of serial recall). Auditory feedback (presence or absence) was manipulated while pianists learned musical pieces from notation and when they later played the pieces from memory. Auditory feedback during learning significantly improved later recall. However, auditory feedback at test did not significantly affect recall, nor was there an interaction between conditions at learning and test. Auditory feedback in music performance appears to be a contextual factor that affects learning but is relatively independent of retrieval conditions.
Gardener, Samantha L; Sohrabi, Hamid R; Shen, Kai-Kai; Rainey-Smith, Stephanie R; Weinborn, Michael; Bates, Kristyn A; Shah, Tejal; Foster, Jonathan K; Lenzo, Nat; Salvado, Olivier; Laske, Christoph; Laws, Simon M; Taddei, Kevin; Verdile, Giuseppe; Martins, Ralph N
Increasing evidence suggests that Alzheimer's disease (AD) sufferers show region-specific reductions in cerebral glucose metabolism, as measured by [18F]-fluoro-2-deoxyglucose positron emission tomography (18F-FDG PET). We investigated preclinical disease stage by cross-sectionally examining the association between global cognition, verbal and visual memory, and 18F-FDG PET standardized uptake value ratio (SUVR) in 43 healthy control individuals, subsequently focusing on differences between subjective memory complainers and non-memory complainers. The 18F-FDG PET regions of interest investigated include the hippocampus, amygdala, posterior cingulate, superior parietal, entorhinal cortices, frontal cortex, temporal cortex, and inferior parietal region. In the cohort as a whole, verbal logical memory immediate recall was positively associated with 18F-FDG PET SUVR in both the left hippocampus and right amygdala. There were no associations observed between global cognition, delayed recall in logical memory, or visual reproduction and 18F-FDG PET SUVR. Following stratification of the cohort into subjective memory complainers and non-complainers, verbal logical memory immediate recall was positively associated with 18F-FDG PET SUVR in the right amygdala in those with subjective memory complaints. There were no significant associations observed in non-memory complainers between 18F-FDG PET SUVR in regions of interest and cognitive performance. We observed subjective memory complaint-specific associations between 18F-FDG PET SUVR and immediate verbal memory performance in our cohort, however found no associations between delayed recall of verbal memory performance or visual memory performance. It is here argued that the neural mechanisms underlying verbal and visual memory performance may in fact differ in their pathways, and the characteristic reduction of 18F-FDG PET SUVR observed in this and previous studies likely reflects the pathophysiological changes in specific
Starc, Martina; Anticevic, Alan; Repovš, Grega
Pupillometry provides an accessible option to track working memory processes with high temporal resolution. Several studies showed that pupil size increases with the number of items held in working memory; however, no study has explored whether pupil size also reflects the quality of working memory representations. To address this question, we used a spatial working memory task to investigate the relationship of pupil size with spatial precision of responses and indicators of reliance on generalized spatial categories. We asked 30 participants (15 female, aged 19-31) to remember the position of targets presented at various locations along a hidden radial grid. After a delay, participants indicated the remembered location with a high-precision joystick providing a parametric measure of trial-to-trial accuracy. We recorded participants' pupil dilations continuously during task performance. Results showed a significant relation between pupil dilation during preparation/early encoding and the precision of responses, possibly reflecting the attentional resources devoted to memory encoding. In contrast, pupil dilation at late maintenance and response predicted larger shifts of responses toward prototypical locations, possibly reflecting larger reliance on categorical representation. On an intraindividual level, smaller pupil dilations during encoding predicted larger dilations during late maintenance and response. On an interindividual level, participants relying more on categorical representation also produced larger precision errors. The results confirm the link between pupil size and the quality of spatial working memory representation. They suggest compensatory strategies of spatial working memory performance-loss of precise spatial representation likely increases reliance on generalized spatial categories. © 2017 Society for Psychophysiological Research.
Root, James C; Ryan, Elizabeth; Barnett, Gregory; Andreotti, Charissa; Bolutayo, Kemi; Ahles, Tim
While forgetfulness is widely reported by breast cancer survivors, studies documenting objective memory performance yield mixed, largely inconsistent, results. Failure to find consistent, objective memory issues may be due to the possibility that cancer survivors misattribute their experience of forgetfulness to primary memory issues rather than to difficulties in attention at the time of learning. To clarify potential attention issues, factor scores for Attention Span, Learning Efficiency, Delayed Memory, and Inaccurate Memory were analyzed for the California Verbal Learning Test-Second Edition (CVLT-II) in 64 clinically referred breast cancer survivors with self-reported cognitive complaints; item analysis was conducted to clarify specific contributors to observed effects, and contrasts between learning and recall trials were compared with normative data. Performance on broader cognitive domains is also reported. The Attention Span factor, but not Learning Efficiency, Delayed Memory, or Inaccurate Memory factors, was significantly affected in this clinical sample. Contrasts between trials were consistent with normative data and did not indicate greater loss of information over time than in the normative sample. Results of this analysis suggest that attentional dysfunction may contribute to subjective and objective memory complaints in breast cancer survivors. These results are discussed in the context of broader cognitive effects following treatment for clinicians who may see cancer survivors for assessment. Copyright © 2014 John Wiley & Sons, Ltd.
Duke, Robert A.; Davis, Carla M.
Using two sequential key press sequences, we tested the extent to which subjects' performance on a digital piano keyboard changed between the end of training and retest on subsequent days. We found consistent, significant improvements attributable to sleep-based consolidation effects, indicating that learning continued after the cessation of…
Sherer, Mark; Davis, Lynne C; Sander, Angelle M; Nick, Todd G; Luo, Chunqiao; Pastorek, Nicholas; Hanks, Robin
(1) To examine the rate of poor performance validity in a large, multicenter, prospectively accrued cohort of community dwelling persons with medically documented traumatic brain injury (TBI), (2) to identify factors associated with Word Memory Test (WMT) performance in persons with TBI. This was a prospective cohort, observational study of 491 persons with medically documented TBI. Participants were administered a battery of cognitive tests, questionnaires on emotional distress and post-concussive symptoms, and a performance validity test (WMT). Additional data were collected by interview and review of medical records. One hundred and seventeen participants showed poor performance validity using the standard cutoff. Variable cluster analysis was conducted as a data reduction strategy. Findings revealed that the 10 cognitive tests and questionnaires could be summarized as 4 indices of emotional distress, speed of cognitive processing, verbal memory, and verbal fluency. Regression models revealed that verbal memory, emotional distress, age, and injury severity (time to follow commands) made unique contribution to prediction of poor performance validity. Poor performance validity was common in a research sample of persons with medically documented TBI who were not evaluated in conjunction with litigation, compensation claims, or current report of symptoms. Poor performance validity was associated with poor performance on cognitive tests, greater emotional distress, lower injury severity, and greater age. Many participants expected to have residual deficits based on initial injury severity showed poor performance validity.
Full Text Available The dorsolateral prefrontal cortex (DLPFC plays a key role in working memory. Evidence indicates that transcranial magnetic stimulation (TMS over the DLPFC can interfere with working memory performance. Here we investigated for how long continuous theta-burst stimulation (cTBS over the DLPFC decreases working memory performance and whether the effect of cTBS on performance depends on working memory load. Forty healthy young subjects received either cTBS over the left DLPFC or sham stimulation before performing a 2-, and 3-back working memory letter task. An additional 0-back condition served as a non-memory-related control, measuring general attention. cTBS over the left DLPFC significantly impaired 2-back working memory performance for about 15 min, whereas 3-back and 0-back performances were not significantly affected. Our results indicate that the effect of left DLPFC cTBS on working memory performance lasts for roughly 15 min and depends on working memory load.
Schicktanz, Nathalie; Fastenrath, Matthias; Milnik, Annette; Spalek, Klara; Auschra, Bianca; Nyffeler, Thomas; Papassotiropoulos, Andreas; de Quervain, Dominique J.-F.; Schwegler, Kyrill
The dorsolateral prefrontal cortex (DLPFC) plays a key role in working memory. Evidence indicates that transcranial magnetic stimulation (TMS) over the DLPFC can interfere with working memory performance. Here we investigated for how long continuous theta-burst stimulation (cTBS) over the DLPFC decreases working memory performance and whether the effect of cTBS on performance depends on working memory load. Forty healthy young subjects received either cTBS over the left DLPFC or sham stimulation before performing a 2-, and 3-back working memory letter task. An additional 0-back condition served as a non-memory-related control, measuring general attention. cTBS over the left DLPFC significantly impaired 2-back working memory performance for about 15 min, whereas 3-back and 0-back performances were not significantly affected. Our results indicate that the effect of left DLPFC cTBS on working memory performance lasts for roughly 15 min and depends on working memory load. PMID:25781012
Kazemi Tari, Somayeh
Although many researchers have worked on memory development, still little is known about what develops in memory development. When one reviews the literature about memory, she encounters many types of memories such as short term vs. long term memory, working memory, explicit vs. implicit memory, trans-saccadic memory, autobiographical memory,…
Cash, Carla D.; Allen, Sarah E.; Simmons, Amy L.; Duke, Robert A.
This study was designed to investigate the extent to which the presentation of an auditory model prior to learning a novel melody affects performance during active practice and the overnight consolidation of procedural memory. During evening training sessions, 32 nonpianist musicians practiced a 13-note keyboard melody with their left…
Ramos, Brian P; Colgan, Leslie A; Nou, Eric; Arnsten, Amy F T
Previous studies using a mixed beta1 and beta2 adrenergic antagonist, propanolol, have indicated that beta adrenoceptors have little effect on the cognitive functioning of the prefrontal cortex. However, recent studies have suggested that endogenous stimulation of beta1 adrenoceptors impairs working memory in both rats and monkeys. Since propanolol has no effect on cognition, we hypothesized that activation of beta2 adrenoceptors might improve performance in a working memory task. We tested this hypothesis by observing the effects of the beta2 agonist, clenbuterol, on spatial working memory performance. Clenbuterol was either infused directly into the prefrontal cortex (rats) or administered systemically (monkeys). Results demonstrated that clenbuterol improved performance in many young and aged rats and monkeys who performed poorly under control conditions. Actions at beta2 adrenoceptors were confirmed by challenging the clenbuterol response with the beta2 adrenergic antagonist, ICI 118,551. The effects of clenbuterol were not universal and depended on the cognitive status of the animal: the drug moderately improved only a subset of animals with working memory impairment.
This study investigated the effects of crowding combined with mood on working memory performance among college students. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web…
Kyttala, Minna; Lehto, Juhani E.
Passive and active visuospatial working memory (VSWM) were investigated in relation to maths performance. The mental rotation task was employed as a measure of active VSWM whereas passive VSWM was investigated using a modified Corsi Blocks task and a matrix pattern task. The Raven Progressive Matrices Test measured fluid intelligence. A total of…
Fay, Marua; Müller, Oliver; vom Brocke, Jan
Recent growth in data volume, variety, and velocity led to an increased demand for high-performance data processing and analytics solutions. In-memory computing (IMC) enables organizations to boost their information processing capacity, and is widely acknowledged to be one of the leading strategi...
Baum, Carolyn Manville; And Others
A study of 133 control subjects and 141 with senile dementia of the Alzheimer type (SDAT) was designed to determine if language, motor planning, and memory were discrete components of performance. It found that patterns were highly individualized, which suggests that apraxia contributes significantly to dysfunction in some people with SDAT. (JOW)
SMITH, RONALD G.
THIS STUDY WAS CONDUCTED DURING 1966 TO DETERMINE THE EFFECTS OF MAGNESIUM PEMOLINE (A COMBINATION OF 2-IMINO-5-PHENYL-4-OXAZOLIDINONE AND MAGNESIUM HYDROXIDE) ON A VARIETY OF HUMAN LEARNING, MEMORY, AND PERFORMANCE TASKS. MAGNESIUM PEMOLINE (25 OR 37.5 MG) OR A PLACEBO WAS ADMINISTERED ORALLY ON A DOUBLE-BLIND BASIS TO INTELLIGENCE-MATCHED GROUPS…
Kundey, Shannon M. A.; De Los Reyes, Andres; Rowan, James D.; Lee, Bern; Delise, Justin; Molina, Sabrina; Cogdill, Lindsay
When learning highly organized sequential patterns of information, humans and nonhuman animals learn rules regarding the hierarchical structures of these sequences. In three experiments, we explored the role of working memory in college students' sequential pattern learning and performance in a computerized task involving a sequential…
Introduction: This study has aimed to investigate the relationship between the development of working memory and performance on arithmetic activities. Method: We conducted a 3-year longitudinal study of a sample of 90 children, that was followed during the first, second and third year of primary school. All children were tested on measures of WM…
The present study sets out to explore the distinctive roles played by two working memory (WM) components in various aspects of L2 task-based speech planning and performance. A group of 40 post-intermediate proficiency level Chinese EFL learners took part in the empirical study. Following the tenets and basic principles of the…
Nagel, Irene E.; Preuschhof, Claudia; Li, Shu-Chen; Nyberg, Lars; Backman, Lars; Lindenberger, Ulman; Heekeren, Hauke R.
Individual differences in working memory (WM) performance have rarely been related to individual differences in the functional responsivity of the WM brain network. By neglecting person-to-person variation, comparisons of network activity between younger and older adults using functional imaging techniques often confound differences in activity…
Vestergaard, Martin; Madsen, Kathrine Skak; Baare, William F. C.; Skimminge, Arnold; Ejersbo, Lisser Rye; Ramsoy, Thomas Z.; Gerlach, Christian; Akeson, Per; Paulson, Olaf B.; Jernigan, Terry L.
During childhood and adolescence, ongoing white matter maturation in the fronto-parietal cortices and connecting fiber tracts is measurable with diffusion-weighted imaging. Important questions remain, however, about the links between these changes and developing cognitive functions. Spatial working memory (SWM) performance improves significantly…
Bell, Martha Ann
Fifty 8-month-old infants participated in a study of the interrelations among cognition, temperament, and electrophysiology. Better performance on a working memory task (assessed using a looking version of the A-not-B task) was associated with increases in frontal-parietal EEG coherence from baseline to task, as well as elevated levels of…
Morasch, Katherine C.; Bell, Martha Ann
This study of infant declarative memory concurrently examined brain-electrical activity and deferred imitation performance in 10-month-old infants. Continuous electroencephalogram (EEG) measures were collected throughout the activity-matched baseline, encoding (modeling) and retrieval (delayed test) phases of a within-subjects deferred imitation…
Cutumisu, Maria; Schwartz, Daniel L.
This paper presents a novel examination of the impact of students' feedback choices and performance on their feedback memory. An empirical study was designed to collect the choices to seek critical feedback from a hundred and six Grade 8 middle-school students via Posterlet, a digital assessment game in which students design posters. Upon…
Chasteen, Alison L; Pichora-Fuller, M Kathleen; Dupuis, Kate; Smith, Sherri; Singh, Gurjit
Memory and hearing are critical domains that interact during older adults' daily communication and social encounters. To develop a more comprehensive picture of how aging influences performance in these domains, the roles of social variables such as views of aging and self-perceived abilities need greater examination. The present study investigates the linkages between views of aging, self-perceived abilities, and performance within and across the domains of memory and hearing, connections that have never been examined together within the same sample of older adults. For both domains, 301 older adults completed measures of their views of aging, their self-perceived abilities and behavioral tests. Using structural equation modeling, we tested a hypothesized model in which older adults' negative views of aging predicted their performance in the domains of memory and hearing through negatively affecting their self-perceived abilities in those domains. Although this model achieved adequate fit, an alternative model in which hearing performance predicted self-perceived hearing also was supported. Both models indicate that hearing influences memory with respect to both behavioral and self-perception measures and that negative views of aging influence self-perceptions in both domains. These results highlight the importance of views of aging and self-perceptions of abilities within and across these domains. (c) 2015 APA, all rights reserved).
Full Text Available The left dorsolateral prefrontal cortex (DLPFC is involved in encoding and retrieval of episodic memories, and thus, is frequently targeted in non-invasive brain stimulation paradigms, aiming for its functional modulation. Anodal transcranial direct current stimulation (tDCS, that boosts neuronal excitability in stimulated cortical areas, has been found to increase cognitive skills differentially, depending on the initial performance. We hypothesize that the benefit of tDCS on verbal episodic memory can be extrapolated from the participants’ baseline performance. In the present randomized, double-blind, parallel group study, healthy young adults (n = 43 received either real anodal or sham tDCS over their left DLPFC during the encoding phase of a verbal episodic memory task. Forty words were presented visually thrice with immediate vocal retrieval after each block and an additional delayed recall. We conducted a moderation analysis to test the modulating effect of initial episodic memory retrieval, adjusted for primacy and recency effects, on delayed recall under real or sham stimulation. Despite the absence of a significantly beneficial tDCS effect at the group level, we found that the number of remembered midlist words in the first retrieval significantly moderated the stimulation effect in such a way that initially low performers experienced the highest gain from real stimulation. These results suggest that anodal tDCS to the left DLPFC improves memory functions only so far. While only marginal stimulation-induced gains occur in cognitively unimpaired populations, greater stimulation benefits might be expected in individuals with clinically relevant deficiencies in the verbal episodic memory domain.
Habich, Annegret; Klöppel, Stefan; Abdulkadir, Ahmed; Scheller, Elisa; Nissen, Christoph; Peter, Jessica
The left dorsolateral prefrontal cortex (DLPFC) is involved in encoding and retrieval of episodic memories, and thus, is frequently targeted in non-invasive brain stimulation paradigms, aiming for its functional modulation. Anodal transcranial direct current stimulation (tDCS), that boosts neuronal excitability in stimulated cortical areas, has been found to increase cognitive skills differentially, depending on the initial performance. We hypothesize that the benefit of tDCS on verbal episodic memory can be extrapolated from the participants' baseline performance. In the present randomized, double-blind, parallel group study, healthy young adults ( n = 43) received either real anodal or sham tDCS over their left DLPFC during the encoding phase of a verbal episodic memory task. Forty words were presented visually thrice with immediate vocal retrieval after each block and an additional delayed recall. We conducted a moderation analysis to test the modulating effect of initial episodic memory retrieval, adjusted for primacy and recency effects, on delayed recall under real or sham stimulation. Despite the absence of a significantly beneficial tDCS effect at the group level, we found that the number of remembered midlist words in the first retrieval significantly moderated the stimulation effect in such a way that initially low performers experienced the highest gain from real stimulation. These results suggest that anodal tDCS to the left DLPFC improves memory functions only so far. While only marginal stimulation-induced gains occur in cognitively unimpaired populations, greater stimulation benefits might be expected in individuals with clinically relevant deficiencies in the verbal episodic memory domain.
Esther Yuet Ying Lau
Full Text Available The main objective was to study the impact of a daytime sleep opportunity on working memory and the mechanism behind such impact. This study adopted an experimental design in a sleep research laboratory. Eighty healthy college students (Age:17-23, 36 males were randomized to either have a polysomnography-monitored daytime sleep opportunity (Nap-group, n=40 or stay awake (Wake-group, n=40 between the two assessment sessions. All participants completed a sleep diary and wore an actigraph-watch for 5 days before and one day after the assessment sessions. They completed the state-measurement of sleepiness and affect, in addition to a psychomotor vigilance test and a working memory task before and after the nap/wake sessions. The two groups did not differ in their sleep characteristics prior to and after the lab visit. The Nap-group had higher accuracy on the working memory task, fewer lapses on the psychomotor vigilance test and lower state-sleepiness than the Wake-group. Within the Nap-group, working memory accuracy was positively correlated with duration of rapid eye movement sleep (REM and total sleep time during the nap. Our findings suggested that "sleep gain" during a daytime sleep opportunity had significant positive impact on working memory performance, without affecting subsequent nighttime sleep in young adult, and such impact was associated with the duration of REM. While REM abnormality has long been noted in pathological conditions (e.g. depression, which are also presented with cognitive dysfunctions (e.g. working memory deficits, this was the first evidence showing working memory enhancement associated with REM in daytime napping in college students, who likely had habitual short sleep duration but were otherwise generally healthy.
Lau, Esther Yuet Ying; Wong, Mark Lawrence; Lau, Kristy Nga Ting; Hui, Florence Wai Ying; Tseng, Chia-huei
The main objective was to study the impact of a daytime sleep opportunity on working memory and the mechanism behind such impact. This study adopted an experimental design in a sleep research laboratory. Eighty healthy college students (Age:17-23, 36 males) were randomized to either have a polysomnography-monitored daytime sleep opportunity (Nap-group, n=40) or stay awake (Wake-group, n=40) between the two assessment sessions. All participants completed a sleep diary and wore an actigraph-watch for 5 days before and one day after the assessment sessions. They completed the state-measurement of sleepiness and affect, in addition to a psychomotor vigilance test and a working memory task before and after the nap/wake sessions. The two groups did not differ in their sleep characteristics prior to and after the lab visit. The Nap-group had higher accuracy on the working memory task, fewer lapses on the psychomotor vigilance test and lower state-sleepiness than the Wake-group. Within the Nap-group, working memory accuracy was positively correlated with duration of rapid eye movement sleep (REM) and total sleep time during the nap. Our findings suggested that "sleep gain" during a daytime sleep opportunity had significant positive impact on working memory performance, without affecting subsequent nighttime sleep in young adult, and such impact was associated with the duration of REM. While REM abnormality has long been noted in pathological conditions (e.g. depression), which are also presented with cognitive dysfunctions (e.g. working memory deficits), this was the first evidence showing working memory enhancement associated with REM in daytime napping in college students, who likely had habitual short sleep duration but were otherwise generally healthy.
Rathmann1, Christian; Fleczok1, Benjamin; Otibar1, Dennis; Kuhlenkötter, Bernd
Shape memory alloys possess an array of unique functional properties which are influenced by a complex interaction of different factors. Due to thermal sensitivity, slight changes in temperature may cause the properties to change significantly. This poses a huge challenge especially for the use of shape memory alloys as actuators. The displacement is the key performance indicator, which has to be of equal or better quality compared to conventional actuators. One problem of shape memory alloys is the change in functional fatigue in the first cycles, which makes it rather difficult to design the actuator. Therefore, the reduction of this shakedown effect is crucial. For this reason, this paper investigates the effect of electrical heat treatment as a method for pre-aging. This topic has so far been little investigated so that the investigations focus on identifying important factors and effects by using the design of experiments.
Palladino, Paola; De Beni, Rossana
Older adults appear to have problems in mental imagery which seem to influence memory, such as in the recall of concrete words. However, the effects of imagery instruction on old participants' memory are quite inconsistent (Richardson, 1980; Salthouse, 1992). Two experiments explored the effects of aging on the nature of mental images generated from non-related nouns, and their memory. A sample of 234 participants, young (20-22 years) young-old (55-65 years), old (66-75 years) and old-old (>75 years), were recruited from universities and recreation centres. In Experiment 1 participants were required to generate mental images and describe them accurately in 40 s. Mental images were classified as general, specific-contextual and self-referred. Details were distinguished between relevant, information useful for describing a mental image and irrelevant, information which is not pertinent, or useful for describing a mental image. A final memory task was proposed. In Experiment 2 evocation and description time was manipulated in order to reduce the production of irrelevant detail: a shorter condition (evocation+description time=20 s) and a longer condition (evocation+description time=40 s). Results show that older adults produce a higher number of general and self-referred images but a lower number of specific images;report a greater quantity of irrelevant detail;recall a lower number of items. Decrease in evocation and description time reduced the irrelevant details and increased older adults' memory performance.
Miotto, Eliane C; Savage, Cary R; Evans, Jonathan J; Wilson, Barbara A; Martin, Maria G M; Balardin, Joana B; Barros, Fabio G; Garrido, Griselda; Teixeira, Manoel J; Amaro Junior, Edson
Memory deficit is a frequent cognitive disorder following acquired prefrontal cortex lesions. In the present study, we investigated the brain correlates of a short semantic strategy training and memory performance of patients with distinct prefrontal cortex lesions using fMRI and cognitive tests. Twenty-one adult patients with post-acute prefrontal cortex (PFC) lesions, twelve with left dorsolateral PFC (LPFC) and nine with bilateral orbitofrontal cortex (BOFC) were assessed before and after a short cognitive semantic training using a verbal memory encoding paradigm during scanning and neuropsychological tests outside the scanner. After the semantic strategy training both groups of patients showed significant behavioral improvement in verbal memory recall and use of semantic strategies. In the LPFC group, greater activity in left inferior and medial frontal gyrus, precentral gyrus and insula was found after training. For the BOFC group, a greater activation was found in the left parietal cortex, right cingulated and precuneus after training. The activation of these specific areas in the memory and executive networks following cognitive training was associated to compensatory brain mechanisms and application of the semantic strategy. Copyright © 2012 Elsevier B.V. All rights reserved.
Redshaw, Jonathan; Henry, Julie D; Suddendorf, Thomas
Previous time-based prospective memory research, both with children and with other groups, has measured the ability to perform an action with the arrival of a time-dependent yet still event-based cue (e.g., the occurrence of a specific clock pattern) while also engaged in an ongoing activity. Here we introduce a novel means of operationalizing time-based prospective memory and assess children's growing capacities when the availability of an event-based cue is varied. Preschoolers aged 3, 4, and 5years (N=72) were required to ring a bell when a familiar 1-min sand timer had completed a cycle under four conditions. In a 2×2 within-participants design, the timer was either visible or hidden and was either presented in the context of a single task or embedded within a dual picture-naming task. Children were more likely to ring the bell before 2min had elapsed in the visible-timer and single-task conditions, with performance improving with age across all conditions. These results suggest a divergence in the development of time-based prospective memory in the presence versus absence of event-based cues, and they also suggest that performance on typical time-based tasks may be partly driven by event-based prospective memory. Copyright © 2016 Elsevier Inc. All rights reserved.
Full Text Available Judgment of learning (JOL plays a pivotal role in self-regulated learning. Although the JOLs are in general accurate, important deviations from memory performance are often reported, especially when the JOLs are made immediately after learning. Nevertheless, existing studies have not clearly dissociated the neural processes underlying subjective JOL and objective memory. In the present study, participants were asked to study a list of words that would be tested one day later. Immediately after learning, participants predicted how likely they would remember that item. Critically, the JOL was performed on only half of the studied items to avoid its contamination on subsequent memory. We found that during encoding, compared to items later judged as will be forgotten, those judged as will be remembered showed stronger activities in the default-mode network, including the ventromedial prefrontal cortex (PFC and posterior cingulate cortex, as well as weaker functional connectivity between the left dorsolateral PFC and the visual cortex. The exact opposite pattern was found when comparing items that were actually remembered with that were later forgotten. These important neural dissociations between JOL and memory performance shed light on the neural mechanisms of human metamemory bias.
Sapkota, Raju P; Pardhan, Shahina; van der Linde, Ian
Visuo-manual interaction in visual short-term memory (VSTM) has been investigated little, despite its importance in everyday tasks requiring the coordination of visual perception and manual action. This study examines the influence of a manual action performed during stimulus learning on a subsequent VSTM test for object appearance. The memory display comprised a sequence of briefly presented 1/f noise discs (i.e., possessing spectral properties akin to natural images), wherein each new stimulus was presented at a unique screen location. Participants either did (or did not) perform a concurrent manual action (spatial tapping) task requiring that a hand-held stylus be moved to a position on a touch tablet that corresponded (or did not correspond) to the screen position of each new stimulus as it appeared. At test, a single stimulus was presented, either at one of the original screen positions, or at a new position. Two factors were examined: the execution (or otherwise) of spatial tapping at a corresponding or non-corresponding position, and the presentation of test stimuli either at their original spatial positions, or at new positions. We find that spatial tapping at corresponding positions elevates VSTM performance by more than 15%, but this occurs only when stimulus positions are matched from memory to test display. Our findings suggest that multimodal attentional focus during stimulus encoding (incorporating visual, spatial, and manual components) leads to stronger, more robust memory representations. We posit several possible explanations for this effect. © 2012 The British Psychological Society.
Mahmood, Omar M; Jacobus, Joanna; Bava, Sunita; Scarlett, Anthony; Tapert, Susan F
Lifetime alcohol hangover and withdrawal symptoms in youth have been shown to predict poorer recall of verbal and nonverbal information, as well as reduced visuospatial skills. Some evidence has suggested that negative effects of alcohol on the brain may be buffered in part by potential neuroprotective properties of cannabinoids. We hypothesized that a history of more alcohol hangover symptoms would predict worse performances on measures of verbal and visual memory, and that this relationship would be moderated by marijuana involvement. Participants were 130 adolescents (65 with histories of heavy marijuana use, and 65 non-marijuana-using controls), ranging in age from 15.7 to 19.1 years. Neuropsychological tests for visual and verbal memory and interviews assessing lifetime and recent substance use, hangover/withdrawal symptoms, and abuse and dependence criteria were administered. Regression models revealed that greater alcohol hangover symptoms predicted worse verbal learning (p Verbal Learning Test, Second Edition) scores for non-marijuana users, but alcohol hangover symptoms were not linked to performance among marijuana users. Alcohol hangover symptoms did not predict visual memory in either group. Results confirm previous studies linking adolescent heavy drinking to reduced verbal learning and memory performance. However, this relationship is not seen in adolescents with similar levels of alcohol involvement who also are heavy users of marijuana.
Smith, Michael E; McEvoy, Linda K; Gevins, Alan
This study examined how sleep loss affects neurophysiologic signals related to attention and working memory. Subjective sleepiness, resting-state electroencephalogram, and behavior and electroencephalogram during performance of working-memory tasks were recorded in a within-subject, repeated-measures design. Data collection occurred in a computerized laboratory setting. Sixteen healthy adults (mean age, 26 years; 8 female) Data from alert daytime baseline tests were compared with data from tests during a late-night, extended-wakefulness session that spanned up to 21 hours of sleep deprivation. Alertness measured both subjectively and electrophysiologically decreased monotonically with increasing sleep deprivation. A lack of alertness-related changes in electroencephalographic measures of the overall mental effort exerted during task execution indicated that participants attempted to maintain high levels of performance throughout the late-night tests. Despite such continued effort, responses became slower, more variable, and more error prone within 1 hour after participants' normal time of sleep onset. This behavior failure was accompanied by significant degradation of event-related brain potentials related to the transient focusing of attention. Moderate sleep loss compromises the function of neural circuits critical to subsecond attention allocation during working-memory tasks, even when an effort is made to maintain wakefulness and performance. Multivariate analyses indicate that combinations of working-memory-related behavior and neurophysiologic measures can be sensitive enough to permit reliable detection of such effects of sleep loss in individuals. Similar methods might prove useful for assessment of functional alertness in patients with sleep disorders.
Zinke, Katharina; Altgassen, Mareike; Mackinlay, Rachael J; Rizzo, Patrizia; Drechsler, Renate; Kliegel, Matthias
The current study investigated prospective memory (PM) performance in children with attention deficit/hyperactivity disorder (ADHD) and controls and aimed at exploring possible underlying factors of PM performance. Twenty-two children with ADHD and 39 age- and ability-matched typically developing children performed a computerized time-based PM task. As predicted, children with ADHD had fewer correct PM responses than controls. Neither differences in overall ongoing task performance nor, remarkably, differences in overall frequency and accuracy of time monitoring were found. Exploratory analyses suggest that individual differences in time monitoring in the final interval before target times may be related to PM performance in ADHD.
Tezduyar, T. E.; Liou, J.
The adaptive implicit-explicit (AIE) approach is presented for the finite-element solution of various problems in computational fluid mechanics. In the AIE approach, the elements are dynamically (adaptively) arranged into differently treated groups. The differences in treatment could be based on considerations such as the cost efficiency, the type of spatial or temporal discretization employed, the choice of field equations, etc. Several numerical tests are performed to demonstrate that this approach can achieve substantial savings in CPU time and memory.
Full Text Available Variation of the gene coding for D2 receptors (DRD2 has been associated with risk for schizophrenia and with working memory deficits. A functional intronic SNP (rs1076560 predicts relative expression of the two D2 receptors isoforms, D2S (mainly pre-synaptic and D2L (mainly post-synaptic. However, the effect of functional genetic variation of DRD2 on striatal dopamine D2 signaling and on its correlation with prefrontal activity during working memory in humans is not known.Thirty-seven healthy subjects were genotyped for rs1076560 (G>T and underwent SPECT with [123I]IBZM (which binds primarily to post-synaptic D2 receptors and with [123I]FP-CIT (which binds to pre-synaptic dopamine transporters, whose activity and density is also regulated by pre-synaptic D2 receptors, as well as BOLD fMRI during N-Back working memory.Subjects carrying the T allele (previously associated with reduced D2S expression had striatal reductions of [123I]IBZM and of [123I]FP-CIT binding. DRD2 genotype also differentially predicted the correlation between striatal dopamine D2 signaling (as identified with factor analysis of the two radiotracers and activity of the prefrontal cortex during working memory as measured with BOLD fMRI, which was positive in GG subjects and negative in GT.Our results demonstrate that this functional SNP within DRD2 predicts striatal binding of the two radiotracers to dopamine transporters and D2 receptors as well as the correlation between striatal D2 signaling with prefrontal cortex activity during performance of a working memory task. These data are consistent with the possibility that the balance of excitatory/inhibitory modulation of striatal neurons may also affect striatal outputs in relationship with prefrontal activity during working memory performance within the cortico-striatal-thalamic-cortical pathway.
Kopasz, Marta; Loessl, Barbara; Valerius, Gabriele; Koenig, Eva; Matthaeas, Nora; Hornyak, Magdolna; Kloepfer, Corinna; Nissen, Christoph; Riemann, Dieter; Voderholzer, Ulrich
Growing evidence indicates that sleep facilitates learning and memory processing. Sleep curtailment is increasingly common in adolescents. The aim of this study was to examine the effects of short-term sleep curtailment on declarative memory consolidation in adolescents. A randomized, cross-over study design was chosen. Twenty-two healthy subjects, aged 14-16 years, spent three consecutive nights in the sleep laboratory with a bedtime of 9 h during the first night (adaptation), 4 h during the second (partial sleep curtailment) and 9 h during the third night (recovery). The control condition consisted of three consecutive nights with bedtimes of 9 h. Both experimental conditions were separated by at least 3 weeks. The acquisition phase for the declarative tests was between 16:00 and 18:00 hours before the second night. Memory performance was examined in the morning after the recovery night. Executive function, attention and concentration were also assessed to control for any possible effects of tiredness. During the 4-h night, we observed a curtailment of 50% of non-rapid eye movement (non-REM), 5% of slow wave sleep (SWS) and 70% of REM sleep compared with the control night. Partial sleep curtailment of one night did not influence declarative memory retrieval significantly. Recall in the paired-associate word list task was correlated positively with percentage of non-REM sleep in the recovery night. Declarative memory consolidation does not appear to be influenced by short-term sleep curtailment in adolescents. This may be explained by the high ability of adolescents to compensate for acute sleep loss. The correlation between non-REM sleep and declarative memory performance supports earlier findings.
An experiment was designed to investigate the effects of translation and performance on memory of words of Sign Language as a second language. An intermediate class of Sign Language learners, whose first language was Japanese, was required to carried out four tasks : translating from Japanese word into Sign Language word, oral reading of Japanese word, translating from Sign Language word into Japanese word, and performing (expressing) of Sign Language word. The subjects were then asked unexpe...
Full Text Available Age-related memory decline has been associated with a faulty regulation of the hypothalamus-pituitary-adrenal axis (HPA-axis. The aim of this study was to investigate whether the magnitude of the stress-induced cortisol increase is related to memory performance when memory is measured in non-stressful conditions. To do so, declarative and working memory performance were measured in 31 men and 35 women between 55 and 77 years of age. On a different day, the magnitude of their cortisol response to acute psychosocial stress was measured. The relationship between the cortisol response and memory performance was U shaped: a low cortisol response to stress was related to poorer declarative and working memory performance, whereas those who did not increase their cortisol levels and those who had the largest cortisol increase had better declarative and working memory capabilities. Sex did not moderate these relationships. These results suggest that a low cortisol response to stress could reflect a defective HPA-axis response to stressors that is accompanied by poorer memory performance. Conversely, a high cortisol response seems to reflect a correct functioning of the HPA-axis and may protect against memory deficits in the later stages of human life.
Differential working memory performance as support for the Kraepelinian dichotomy between schizophrenia and bipolar disorder? An experimental neuropsychological study using circuit-specific working memory tasks.
Zilles, David; Jung, Raphael; Gruber, Eva; Falkai, Peter; Gruber, Oliver
The traditional clinical dichotomy of schizophrenia and bipolar disorder has been challenged by recent findings of an at least in part common genetic basis. The investigation of neurocognitive functions like working memory may thereby contribute to elucidate common versus distinct pathophysiological processes of the major psychoses. To date direct comparisons of working memory functioning in schizophrenia and bipolar disorder have been rare and moreover have revealed inconsistent findings. In this study we aimed to further clarify the diagnostic specificity of working memory deficits in schizophrenia and bipolar disorder. Fifty patients with schizophrenia, 23 patients with bipolar disorder and 53 healthy controls were tested with regard to specific dysfunctions of verbal and visuospatial working memory components using a set of well-characterized, brain circuit-specific paradigms with established brain-behaviour relationships. Patients with schizophrenia showed marked deficits across different working memory domains while bipolar patients performed intermediate with no significant differences compared to the control group. Working memory performance of patients with schizophrenia and bipolar disorder significantly differed in only one particular task requiring articulatory rehearsal of verbal information. While these results do not provide unequivocal support for the Kraepelinian dichotomy, they are consistent with recent findings suggesting the existence of a specific subgroup of schizophrenia patients phenotypically characterized by selective deficits of the articulatory rehearsal mechanism of verbal working memory.
Schoeni, Anna; Roser, Katharina; Röösli, Martin
The aim of this study is to investigate whether memory performance in adolescents is affected by radiofrequency electromagnetic fields (RF-EMF) from wireless device use or by the wireless device use itself due to non-radiation related factors in that context. We conducted a prospective cohort study with 439 adolescents. Verbal and figural memory tasks at baseline and after one year were completed using a standardized, computerized cognitive test battery. Use of wireless devices was inquired by questionnaire and operator recorded mobile phone use data was obtained for a subgroup of 234 adolescents. RF-EMF dose measures considering various factors affecting RF-EMF exposure were computed for the brain and the whole body. Data were analysed using a longitudinal approach, to investigate whether cumulative exposure over one year was related to changes in memory performance. All analyses were adjusted for relevant confounders. The kappa coefficients between cumulative mobile phone call duration and RF-EMF brain and whole body dose were 0.62 and 0.67, respectively for the whole sample and 0.48 and 0.28, respectively for the sample with operator data. In linear exposure-response models an interquartile increase in cumulative operator recorded mobile phone call duration was associated with a decrease in figural memory performance score by -0.15 (95% CI: -0.33, 0.03) units. For cumulative RF-EMF brain and whole body dose corresponding decreases in figural memory scores were -0.26 (95% CI: -0.42, -0.10) and -0.40 (95% CI: -0.79, -0.01), respectively. No exposure-response associations were observed for sending text messages and duration of gaming, which produces tiny RF-EMF emissions. A change in memory performance over one year was negatively associated with cumulative duration of wireless phone use and more strongly with RF-EMF dose. This may indicate that RF-EMF exposure affects memory performance. Copyright © 2015 Elsevier Ltd. All rights reserved.
Lin, Tzu-Wei; Chen, Shean-Jen; Huang, Tung-Yi; Chang, Chia-Yuan; Chuang, Jih-Ing; Wu, Fong-Sen; Kuo, Yu-Min; Jen, Chauying J
Different exercise paradigms show differential effects on various forms of memory. We hypothesize that the differential effects of exercises on memory performance are caused by different neuroplasticity changes in relevant brain regions in response to different exercise trainings. We examined the effects of treadmill running (TR) and wheel running (WR) on the Pavlovian fear conditioning task that assesses learning and memory performance associated with the amygdala (cued conditioning) and both the amygdala and hippocampus (contextual conditioning). The skeletal muscle citrate synthase activity, an indicator of aerobic capacity, was elevated in rats received 4 w of TR, but not WR. While both TR and WR elevated the contextual conditional response, only TR facilitated the cued conditional response. Using a single-neuron labeling technique, we found that while both TR and MR enlarged the dendritic field and increased the spine density in hippocampal CA3 neurons, only TR showed these effects in basolateral amygdalar neurons. Moreover, both types of exercise upregulated synaptic proteins (i.e., TrkB and SNAP-25) in the hippocampus; however only TR showed similar effects in the amygdala. Injection of K252a, a TrkB kinase inhibitor, in the dorsal hippocampus or basolateral amygdala abolished the exercise-facilitated contextual or cued fear learning and memory performance, respectively, regardless of the types of exercise. In summary, our results supported that different types of exercise affect the performance of learning and memory via BDNF-TrkB signaling and neuroplasticity in specific brain regions. The brain region-specific neuronal adaptations are possibly induced by various levels of intensity/stress elicited by different types of exercise. Copyright © 2011 Elsevier Inc. All rights reserved.
Ding, Hui; Qin, Wen; Jiang, Tianzi; Zhang, Yunting; Yu, Chunshui
We aimed to investigate the relationship between structural variations in the cerebellum and individual differences in working memory performance as assessed by average reaction time (RT) and correction rate (CR) on a 3-back task. High-resolution T1-weighted magnetic resonance images were acquired in 311 healthy young adults. Voxel-based morphometry (VBM) was used to identify cerebellar areas with volumes correlated to working memory performance when controlling for age, gender, years of education and handedness. We found that RT was positively correlated with the grey matter volume (GMV) bilaterally in cerebellar lobules IV/V, VI and VIII, in vermis VII/VIII and in left Crus I; CR was positively correlated with the GMV in the left lobule VI and Crus I. These findings suggest that RT on a working memory task is related to structural variation in both motor and cognitive subregions of the cerebellum, while CR is mainly associated with the cognitive subregions. Our findings provide further evidence that the cerebellum contributes to working memory function. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.
Enge, Sören; Fleischhauer, Monika; Lesch, Klaus-Peter; Reif, Andreas; Strobel, Alexander
Emerging evidence from studies using, for example, acute tryptophan depletion or investigating genetic variation of genes related to the serotonin signaling pathway suggest a role of serotonin in executive functions such as top-down attention, working memory and inhibitory control. In the current study, we aimed at extending this evidence by using the n-back task to examine working memory performance of 130 participants via behavioral and neurophysiological indices and by focusing on variations within genes encoding key regulators of the serotonergic system: the serotonin transporter gene-linked polymorphic region (5-HTTLPR) and a repeat polymorphism in the transcriptional control region of the monoamine-oxidase gene (MAOA-uVNTR). Because serotonin and norepinephrine systems have been shown to be structurally and functionally highly interrelated, we also examined a novel polymorphism in the promoter region of the norepinephrine transporter gene (NET -3081) in anticipation of epistatic effects. We found that carriers of 5-HTTLPR and MAOA-uVNTR alleles recently implicated in executive processing showed a more efficient executive control of working memory-related performance as evidenced by reaction time, error rate as well as N2 and P3b event-related potential measures. This impact was further supported by interactions with the NET polymorphism. Linking serotonergic influence to mechanisms of inhibitory response control implicated in working memory, our results provide further support for and add new evidence concerning the importance of serotonergic neuromodulation in executive functioning. Copyright Â© 2011 Elsevier Ltd. All rights reserved.
Ellmore, Timothy M; Ng, Kenneth; Reichert, Chelsea P
Sustained and elevated activity during the working memory delay period has long been considered the primary neural correlate for maintaining information over short time intervals. This idea has recently been reinterpreted in light of findings generated from multiple neural recording modalities and levels of analysis. To further investigate the sustained or transient nature of activity, the temporal-spectral evolution (TSE) of delay period activity was examined in humans with high density EEG during performance of a Sternberg working memory paradigm with a relatively long six second delay and with novel scenes as stimuli. Multiple analyses were conducted using different trial window durations and different baseline periods for TSE computation. Sensor level analyses revealed transient rather than sustained activity during delay periods. Specifically, the consistent finding among the analyses was that high amplitude activity encompassing the theta range was found early in the first three seconds of the delay period. These increases in activity early in the delay period correlated positively with subsequent ability to distinguish new from old probe scenes. Source level signal estimation implicated a right parietal region of transient early delay activity that correlated positively with working memory ability. This pattern of results adds to recent evidence that transient rather than sustained delay period activity supports visual working memory performance. The findings are discussed in relation to synchronous and desynchronous intra- and inter-regional neural transmission, and choosing an optimal baseline for expressing temporal-spectral delay activity change.
Yang, Jing; Li, Ping
Are explicit versus implicit learning mechanisms reflected in the brain as distinct neural structures, as previous research indicates, or are they distinguished by brain networks that involve overlapping systems with differential connectivity? In this functional MRI study we examined the neural correlates of explicit and implicit learning of artificial grammar sequences. Using effective connectivity analyses we found that brain networks of different connectivity underlie the two types of learning: while both processes involve activation in a set of cortical and subcortical structures, explicit learners engage a network that uses the insula as a key mediator whereas implicit learners evoke a direct frontal-striatal network. Individual differences in working memory also differentially impact the two types of sequence learning. PMID:22952624
James Hugo Smith-Spark
Full Text Available Prospective memory (PM is memory for delayed intentions. While deleterious effects of acute doses of alcohol on PM have been documented previously using between-subjects comparisons, the current study adopted a single blind placebo-controlled within-subjects design to explore whether the extent to which alcohol-related impairments in PM are mediated by executive functions (EFs. To this end, 52 male social drinkers with no history of substance-related treatment were tested using two parallel versions of a clinical measure of PM (the Memory for Intentions Test; Raskin, Buckheit & Sherrod, 2010, and a battery of EF measures. Testing took place on two occasions, with the order of administration of the alcohol and placebo conditions being fully counterbalanced. Overall, PM was worse under alcohol and participants showed deficits on five of the six subscales making up the clinical test. Hierarchical multiple regression analyses demonstrated that EFs did not predict PM performance decrements overall but did predict performance when time cues were presented and when verbal responses were required. Phonemic fluency was the strongest of the EF predictors; a greater capacity to gain controlled access to information in long-term memory predicted a smaller difference between placebo- and alcohol-related performance on both the time cue and verbal response scales. Prospective memory is crucial to compliance with, and response to, both therapy programmes and alcohol harm prevention campaigns. The results indicate that individual differences in cognitive function need to be taken into account when designing such interventions in order to increase their effectiveness.
MacPherson, Sarah E; Turner, Martha S; Bozzali, Marco; Cipolotti, Lisa; Shallice, Tim
Memory deficits in patients with frontal lobe lesions are most apparent on free recall tasks that require the selection, initiation, and implementation of retrieval strategies. The effect of frontal lesions on recognition memory performance is less clear with some studies reporting recognition memory impairments but others not. The majority of these studies do not directly compare recall and recognition within the same group of frontal patients, assessing only recall or recognition memory performance. Other studies that do compare recall and recognition in the same frontal group do not consider recall or recognition tests that are comparable for difficulty. Recognition memory impairments may not be reported because recognition memory tasks are less demanding. This study aimed to investigate recall and recognition impairments in the same group of 47 frontal patients and 78 healthy controls. The Doors and People Test was administered as a neuropsychological test of memory as it assesses both verbal and visual recall and recognition using subtests that are matched for difficulty. Significant verbal and visual recall and recognition impairments were found in the frontal patients. These results demonstrate that when frontal patients are assessed on recall and recognition memory tests of comparable difficulty, memory impairments are found on both types of episodic memory test. (c) 2016 APA, all rights reserved).
Drake, Christopher L; Roehrs, Timothy; Turner, Lauren; Scofield, Holly M; Roth, Thomas
Caffeine has been shown to reverse some of the performance-impairing effects of ethanol. However, it is not known whether this antagonistic effect of caffeine is mediated by a reduction in sleepiness. The present study assessed physiological alertness/sleepiness, memory, and psychomotor performance following the administration of placebo, ethanol, and caffeine+ethanol combinations. A total of 13 healthy individuals (21-35 years old) underwent four conditions presented in a Latin Square Design: placebo-placebo, ethanol (0.5 g/kg)-placebo, ethanol (0.5 g/kg)-caffeine 150 mg, and ethanol (0.5 g/kg)-caffeine 300-mg. The Multiple Sleep Latency Test (MSLT), psychomotor performance battery, memory test, and mood/sleepiness questionnaires were administered following each condition. The peak breadth ethanol concentration (BrEC) was 0.043+/-0.0197% and did not differ among the three caffeine treatments. As expected, ethanol reduced mean latency on the MSLT. The lowest caffeine dose reversed this effect and the highest dose increased mean latency (greater alertness) significantly beyond placebo levels. Ethanol also impaired psychomotor performance and memory. The 300-mg caffeine dose restored performance and memory measures to placebo levels. Although visual analog ratings of dizziness were increased by ethanol, they were not diminished by either caffeine dose. In conclusion, Low-dose caffeine prevented the sleepiness and performance impairment associated with a moderate dose of ethanol. Thus, caffeine, similar to other stimulants, can reverse the physiologically sedating effects of ethanol, although other negative effects remain.
Macpherson, S; Turner, M; Bozzali, M.; Cipolotti, L.; Shallice, T.
Objective: Memory deficits in patients with frontal lobe lesions are most apparent on free recall tasks that require the selection, initiation, and implementation of retrieval strategies. The effect of frontal lesions on recognition memory performance is less clear with some studies reporting recognition memory impairments but others not. The majority of these studies do not directly compare recall and recognition within the same group of frontal patients, assessing only recall or recognition...
Greenwood, Pamela M.; Sundararajan, Ramya; Lin, Ming-Kuan; Kumar, Reshma; Fryxell, Karl J.; Parasuraman, Raja
We investigated the relation between the two systems of visuospatial attention and working memory by examining the effect of normal variation in cholinergic and noradrenergic genes on working memory performance under attentional manipulation. We previously reported that working memory for location was impaired following large location precues, indicating the scale of visuospatial attention has a role in forming the mental representation of the target. In one of the first studies to compare ef...
Costa, Alberto; Peppe, Antonella; Zabberoni, Silvia; Serafini, Francesca; Barban, Francesco; Scalici, Francesco; Caltagirone, Carlo; Carlesimo, Giovanni Augusto
Prospective memory (PM) is the ability to keep in memory and realize future intentions. We aimed at investigating whether in Parkinson's disease (PD) PM deficits are related to mild cognitive impairment (MCI). Other aims were to investigate the cognitive abilities underlying PM performance, and the association between PM performance and measures of daily living functioning. The study included 15 PD patients with single domain MCI, 15 with multiple domain MCI, 17 PD patients without cognitive disorders (PDNC) and 25 healthy controls (HCs). All subjects were administered a PM procedure that included focal (PM cue is processed in the ongoing task) and nonfocal (PM cue is not processed in the ongoing task) conditions. PD patients were administered an extensive neuropsychological battery and scales to assess daily living abilities. PD patients with MCI (both single and multiple domains) showed lower accuracy on all PM conditions than both HC and PDNC patients. This was predicted by their scores on shifting indices. Conversely, PM accuracy of PDNC patients was comparable to HCs. Regression analyses revealed that PD patients' PM performance significantly predicted scores on daily living scales Conclusions: Results suggest that PM efficiency is not tout-court reduced in PD patients, but it specifically depends on the presence of MCI. Moreover, decreased executive functioning, but not episodic memory failure, accounts for a significant proportion of variance in PM performance. Finally, PM accuracy indices were found to be associated with measures of global daily living functioning and management of medication. (c) 2015 APA, all rights reserved).
Buhle, Jason; Wager, Tor D
It is widely assumed that distraction reduces pain. Similarly, it is assumed that pain distracts from concurrent, unrelated cognitive processing, reducing performance on difficult tasks. Taken together, these assumptions suggest pain processing and cognitive function engage an overlapping set of domain-general, capacity-limited mental resources. However, experimental tests of this proposal have yielded mixed results, leading to alternative proposals that challenge the common model of a bidirectional relationship between concurrent pain and task performance. We tested these contrasting positions using a novel concurrent pain and executive working memory paradigm. Both task difficulty and nociceptive stimulus intensity were individually calibrated for each participant. Participants reported less pain during the working memory task than a visually matched control condition. Conversely, increasing levels of heat incrementally reduced task performance. Path analyses showed that variations in pain completely mediated this effect, and that even within a given heat level, trial-by-trial fluctuations in pain predicted decrements in performance. In sum, these findings argue that overlapping cognitive resources play a role in both pain processing and executive working memory. Future studies could use this paradigm to understand more precisely which components of executive function or other cognitive resources contribute to the experience of pain. Copyright 2009 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.
Deptuch, Gregory [Fermilab; Hoff, James [Fermilab; Jindariani, Sergo [Fermilab; Liu, Tiehui [Fermilab; Olsen, Jamieson [Fermilab; Tran, Nhan [Fermilab; Joshi, Siddhartha [Northwestern U.; Li, Dawei [Northwestern U.; Ogrenci-Memik, Seda [Northwestern U.
Extremely fast pattern recognition capabilities are necessary to find and fit billions of tracks at the hardware trigger level produced every second anticipated at high luminosity LHC (HL-LHC) running conditions. Associative Memory (AM) based approaches for fast pattern recognition have been proposed as a potential solution to the tracking trigger. However, at the HL-LHC, there is much less time available and speed performance must be improved over previous systems while maintaining a comparable number of patterns. The Vertically Integrated Pattern Recognition Associative Memory (VIPRAM) Project aims to achieve the target pattern density and performance goal using 3DIC technology. The first step taken in the VIPRAM work was the development of a 2D prototype (protoVIPRAM00) in which the associative memory building blocks were designed to be compatible with the 3D integration. In this paper, we present the results from extensive performance studies of the protoVIPRAM00 chip in both realistic HL-LHC and extreme conditions. Results indicate that the chip operates at the design frequency of 100 MHz with perfect correctness in realistic conditions and conclude that the building blocks are ready for 3D stacking. We also present performance boundary characterization of the chip under extreme conditions.
Lindeløv, Jonas K; Overgaard, Rikke; Overgaard, Morten
Working memory impairment is prevalent in brain injured patients across lesion aetiologies and severities. Unfortunately, rehabilitation efforts for this impairment have hitherto yielded small or no effects. Here we show in a randomized actively controlled trial that working memory performance can be effectively restored by suggesting to hypnotized patients that they have regained their pre-injury level of working memory functioning. Following four 1-h sessions, 27 patients had a medium-sized improvement relative to 22 active controls (Bayes factors of 342 and 37.5 on the two aggregate outcome measures) and a very large improvement relative to 19 passive controls (Bayes factor = 1.7 × 1013). This was a long-term effect as revealed by no deterioration following a 6.7 week no-contact period (Bayes factors = 7.1 and 1.3 in favour of no change). To control for participant-specific effects, the active control group was crossed over to the working memory suggestion and showed superior improvement. By the end of the study, both groups reached a performance level at or above the healthy population mean with standardized mean differences between 1.55 and 2.03 relative to the passive control group. We conclude that, if framed correctly, hypnotic suggestion can effectively improve working memory following acquired brain injury. The speed and consistency with which this improvement occurred, indicate that there may be a residual capacity for normal information processing in the injured brain. © The Author (2017). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: firstname.lastname@example.org.
Ring, Melanie; Gaigg, Sebastian B; Bowler, Dermot M
This study tested implicit and explicit spatial relational memory in Autism Spectrum Disorder (ASD). Participants were asked to study pictures of rooms and pictures of daily objects for which locations were highlighted in the rooms. Participants were later tested for their memory of the object locations either by being asked to place objects back into their original locations or into new locations. Proportions of times when participants choose the previously studied locations for the objects irrespective of the instruction were used to derive indices of explicit and implicit memory [process-dissociation procedure, Jacoby, 1991, 1998]. In addition, participants performed object and location recognition and source memory tasks where they were asked about which locations belonged to the objects and which objects to the locations. The data revealed difficulty for ASD individuals in actively retrieving object locations (explicit memory) but not in subconsciously remembering them (implicit memory). These difficulties cannot be explained by difficulties in memory for objects or locations per se (i.e., the difficulty pertains to object-location relations). Together these observations lend further support to the idea that ASD is characterised by relatively circumscribed difficulties in relational rather than item-specific memory processes and show that these difficulties extend to the domain of spatial information. They also lend further support to the idea that memory difficulties in ASD can be reduced when support is provided at test. © 2015 International Society for Autism Research, Wiley Periodicals, Inc.
Tsai, Chia-Liang; Chang, Yu-Kai; Hung, Tsung-Min; Tseng, Yu-Ting; Chen, Tzu-Chi
The objective of this study was to investigate the mechanisms underlying the deficit in visuospatial working memory (VSWM) seen in children with developmental coordination disorder (DCD) and to compare brain activity while performing a VSWM task in children with DCD and typically developing children. Behavioural performance and event-related potentials (ERPs) were recorded in 24 children (12 males, 12 females; mean age 139 mo, SD 4 mo) with DCD (as determined by a score ERP data suggests that children with DCD have deficits of visuospatial working memory owing to fewer resources being allocated to comparison of spatial locations, less effort allotted to the response selection, and less neural processing employed during the retrieval process phase. © The Authors. Developmental Medicine & Child Neurology © 2012 Mac Keith Press.
Lee, Kerry; Ng, Swee-Fong; Ng, Ee-Lynn; Lim, Zee-Ying
Previous studies on individual differences in mathematical abilities have shown that working memory contributes to early arithmetic performance. In this study, we extended the investigation to algebraic word problem solving. A total of 151 10-year-olds were administered algebraic word problems and measures of working memory, intelligence quotient (IQ), and reading ability. Regression results were consistent with findings from the arithmetic literature showing that a literacy composite measure provided greater contribution than did executive function capacity. However, a series of path analyses showed that the overall contribution of executive function was comparable to that of literacy; the effect of executive function was mediated by that of literacy. Both the phonological loop and the visual spatial sketchpad failed to contribute directly; they contributed only indirectly by way of literacy and performance IQ, respectively.
Many theories addressing the complex anxiety-cognition interaction are built upon the notion that working memory is vulnerable to the effects of anxiety. However, most research has utilised studies of trait anxiety which does not allow direct inferences to be made between affect and cognitive performance, or exclude confounds such as pre-existing individual differences. As a result, a systematic review was undertaken to explore the neuropsychological consequences of experimentally-induced sta...
Miranda, B.; Madureira, S.; Verdelho, A.
. A question about self-perceived memory impairment was used as a measure for presence of memory complaints. Cognitive performance was analysed test-by-test and in three main domains: memory, executive functions and speed/motor control. The Geriatric Depression Scale (GDS) was used as a measure of depressive...... symptoms. RESULTS: Six hundred and thirty-eight subjects were included in this study. No association was found between memory complaints and the severity of WMC. Subjects with memory complaints (n = 399) had a higher GDS score [t((637)) = -7.15; ptests......OBJECTIVES: To determine whether self-perceived memory impairment is associated with the severity of white matter changes (WMC) and is related to cognitive impairment. METHODS: Data were drawn from the multinational Leukoaraiosis and Disability Study (LADIS), which investigates the impact of WMC...
Chevalier, Nicolas; James, Tiffany D.; Wiebe, Sandra A.; Nelson, Jennifer Mize; Espy, Kimberly Andrews
The present study addressed whether developmental improvement in working memory span task performance relies upon a growing ability to proactively plan response sequences during childhood. Two hundred thirteen children completed a working memory span task in which they used a touchscreen to reproduce orally presented sequences of animal names.…
Tu, Hsiao-Wei; Hampton, Robert R
Multiple memory systems often act together to generate behavior, preventing a simple one-to-one mapping between cognitive processes and performance in specific tests. Process dissociation procedures (PDPs) have been adopted in both humans and monkeys to quantify one-trial memory and habit, with the assumption that these two processes make independent contributions to performance. Violations of this independence assumption could produce artificial dissociations. Evidence for independence has been reported in humans, but similar tests have not been conducted with monkeys until now. In a within-subjects design using a matching-to-sample task, we manipulated one-trial memory strength and habit strength simultaneously. Memory delay intervals and encoding conditions affected one-trial memory scores without affecting habit scores. In contrast, biased reinforcement selectively changed habit scores but not one-trial memory scores. This behavioral double dissociation clearly shows that one-trial memory and habit can be manipulated independently, validating PDP as a valuable tool for cross-species studies of learning and memory and reinforcing the view that one-trial memory and habits are served by distinct brain systems.
Missaire, Mégane; Fraize, Nicolas; Joseph, Mickaël Antoine; Hamieh, Al Mahdy; Parmentier, Régis; Marighetto, Aline; Salin, Paul Antoine; Malleret, Gaël
A distinction has always been made between long-term and short-term memory (also now called working memory, WM). The obvious difference between these two kinds of memory concerns the duration of information storage: information is supposedly transiently stored in WM while it is considered durably consolidated into long-term memory. It is well acknowledged that the content of WM is erased and reset after a short time, to prevent irrelevant information from proactively interfering with newly stored information. In the present study, we used typical WM radial maze tasks to question the brief lifespan of spatial WM content in rodents. Groups of rats were submitted to one of two different WM tasks in a radial maze: a WM task involving the repetitive presentation of a same pair of arms expected to induce a high level of proactive interference (PI) (HIWM task), or a task using a different pair in each trial expected to induce a low level of PI (LIWM task). Performance was effectively lower in the HIWM group than in LIWM in the final trial of each training session, indicative of a "within-session/short-term" PI effect. However, we also observed a different "between-session/long-term" PI effect between the two groups: while performance of LIWM trained rats remained stable over days, the performance of HIWM rats dropped after 10 days of training, and this impairment was visible from the very first trial of the day, hence not attributable to within-session PI. We also showed that a 24 hour-gap across training sessions known to allow consolidation processes to unfold, was a necessary and sufficient condition for the long-term PI effect to occur. These findings suggest that in the HIWM task, WM content was not entirely reset between training sessions and that, in specific conditions, WM content can outlast its purpose by being stored more permanently, generating a long-term deleterious effect of PI. The alternative explanation is that WM content could be transferred and stored
Euler, Matthew J; Wiltshire, Travis J; Niermeyer, Madison A; Butner, Jonathan E
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. Copyright © 2016 Elsevier B.V. All rights reserved.
Zamroziewicz, Marta; Raskin, Sarah A; Tennen, Howard; Austad, Carol S; Wood, Rebecca M; Fallahi, Carolyn R; Dager, Alecia D; Sawyer, Broderick; Leen, Samantha; Pearlson, Godfrey D
Traditional college students are at a critical juncture in the development of prospective memory (PM). Their brains are vulnerable to the effects of alcohol. There were 123 third and fourth year college students, 19-23 years old, who completed the Self-Rating Effects of Alcohol (SREA), Modified Timeline Follow-back (TFLB), Brief Young Adult Alcohol Consequences Scale (BYAACS), and Alcohol Effects Questionnaire (AEQ) once per month on a secure online database, as reported elsewhere (Dager et al., 2013). Data from the 6 months immediately before memory testing were averaged. In a single testing session participants were administered the Mini International Neuropsychiatric Interview-Diagnostic and Statistical Manual for Mental Disorders-Fourth Edition-Text Revision (MINI-DSM-IV-TR), measures of PM (event-based and time-based), and retrospective memory (RM). Based on the average score of six consecutive monthly responses to the SREA, TLFB, and AEQ, students were classified as nondrinkers, light drinkers, or heavy drinkers (as defined previously; Dager et al., 2013). Alcohol-induced amnesia (blackout) was measured with the BYAACS. We found a relationship between these alcohol use classifications and time-based PM, such that participants who were classified as heavier drinkers were more likely to forget to perform the time-based PM task. We also found that self-reported alcohol-induced amnesia (blackouts) during the month immediately preceding memory testing was associated with lower performance on the event-based PM task. Participants' ability to recall the RM tasks suggested the PM items were successfully encoded even when they were not carried out, and we observed no relationship between alcohol use and RM performance. Heavy alcohol use in college students may be related to impairments in PM. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
Hamel, Raphaël; Trempe, Maxime; Bernier, Pierre-Michel
Upon exposure to a new sensorimotor relationship, motor behaviors iteratively change early in adaptation but eventually stabilize as adaptation proceeds. Behavioral work suggests that motor memory consolidation is initiated upon the attainment of asymptotic levels of performance. Separate lines of evidence point to a critical role of the primary motor cortex (M1) in consolidation. However, a causal relationship between M1 activity during asymptote and consolidation has yet to be demonstrated. The present study investigated this issue in male and female participants using single-pulse transcranial magnetic stimulation (TMS) to interfere with postmovement activity in M1 in two behavioral phases of a ramp-and-hold visuomotor adaptation paradigm. TMS was either provided after each trial of the ramp phase of adaptation when a gradual increase in the visuomotor rotation caused movements to be changing, or after each trial of the hold phase of adaptation when the rotation was held constant and movements tended to stabilize. Consolidation was assessed by measuring performance on the same task 24 h later. Results revealed that TMS did not influence adaptation to the new visuomotor relationship in either condition. Critically, however, TMS disruption of M1 activity selectively impaired consolidation of motor memories when it was provided during the hold phase of adaptation. This effect did not take place when TMS was delivered over adjacent dorsal premotor cortex or when motor behaviors in late adaptation were prevented from plateauing. Together, these data suggest that the impaired consolidation stemmed from interference with mechanisms of repetition-dependent plasticity in M1.SIGNIFICANCE STATEMENT The present work demonstrates that TMS disruption of M1 activity impairs the consolidation of motor memories selectively when performance reaches asymptotic levels during sensorimotor adaptation. These findings provide evidence for a causal contribution of M1 to motor memory
Logan, S Wood; Fischman, Mark G
In two experiments we examined the relationship between end-state comfort effects and memory performance in serial and free recall. In Experiment 1, 24 university students completed a bimanual end-state comfort task and a memory task. Participants viewed a series of 11 letters, then performed the bimanual overturned glass task in which they simultaneously moved two glasses from an upper shelf to a lower shelf, and then recalled the letters in either serial or free recall conditions. Memory recall was evaluated based on the presence or absence of primacy and recency effects. The end-state comfort effect was assessed by the percentage of initial hand positions that allowed the hands to end up in a comfortable thumbs-up posture. The end-state comfort effect was present in both memory conditions. The results revealed the disappearance of the recency effect in serial and free recall, although the effect was much stronger during serial recall. In Experiment 2, we asked whether simpler motor tasks might bring back the recency effect. Forty-eight participants completed either a bimanual or unimanual task that involved moving non-descript plastic cylinder(s) from an upper shelf to a lower shelf. An unexpected finding was that even after performance of the simpler motor tasks, the recency effect was still absent. The disappearance of the recency effect, regardless of the complexity of the motor task, suggests a reciprocal influence of physical action and cognitive processes, which we interpret as a basic concurrence cost. Copyright © 2011 Elsevier B.V. All rights reserved.
Steenbergen, B.; Kamp, J. van der; Verneau, M.; Jongbloed-Pereboom, M.; Masters, R.S.
PURPOSE: Motor skills can be learned in an explicit or an implicit manner. Explicit learning places high demands on working memory capacity, but engagement of working memory is largely circumvented when skills are learned implicitly. We propose that individuals with impaired movement dynamics may
Steenbergen, B.; Kamp, J. van der; Verneau, M.; Jongbloed-Pereboom, M.; Masters, R.S.W.
Purpose - Motor skills can be learned in an explicit or an implicit manner. Explicit learning places high demands on working memory capacity, but engagement of working memory is largely circumvented when skills are learned implicitly. We propose that individuals with impaired movement dynamics may
Nielsen, Martin Bjerre; Krenk, Steen
A two‐node free‐floating beam element capable of undergoing arbitrary large displacements and finite rotations is presented in explicit form. The configuration of the beam in three‐dimensional space is represented by the global components of the position of the beam nodes and an associated set of...... interpolation of kinematic variables, resulting in a locking‐free formulation in terms of three explicit matrices. A set of classic benchmark examples illustrates excellent performance of the explicit beam element. Copyright © 2014 John Wiley & Sons, Ltd....
Owens, Matthew; Stevenson, Jim; Hadwin, Julie A; Norgate, Roger
Cognitive interference theories (e.g. attentional control theory, processing efficiency theory) suggest that high levels of trait anxiety predict adverse effects on the performance of cognitive tasks, particularly those that make high demands on cognitive resources. We tested an interaction hypothesis to determine whether a combination of high anxiety and low working memory capacity (WMC) would predict variance in demanding cognitive test scores. Ninety six adolescents (12- to 14-years-old) participated in the study, which measured self-report levels of trait anxiety, working memory, and cognitive test performance. As hypothesized, we found that the anxiety-WMC interaction explained a significant amount of variance in cognitive test performance (ΔR(2) .07, p .10). In contrast, trait anxiety was negatively related to test performance in adolescents with low WMC (β = -.35, p < .05) and positively related to test performance in those with high WMC (β = .49, p < .01). The results of this study suggest that WMC moderates the relationship between anxiety and cognitive test performance and may be a determinant factor in explaining some discrepancies found in the literature. Further research is needed to fully understand the mechanisms involved. © 2012 The British Psychological Society.
Vaccarino, Sophie R; Rajji, Tarek K; Gildengers, Ariel G; Waters, Sarah E S; Butters, Meryl A; Menon, Mahesh; Blumberger, Daniel M; Voineskos, Aristotle N; Miranda, Dielle; Mulsant, Benoit H
Older patients with bipolar disorder (BD) present with variable degrees of cognitive impairment. Over time, stress, mood episodes, and comorbidities increase the body's allostatic load. We assessed the extent to which allostatic load vs more traditional measures of medical burden account for the heterogeneity in cognition in this population. Thirty-five older euthymic patients with BD and 30 age-equated, gender-equated, and education-equated comparison participants were administered a comprehensive assessment including a neuropsychological battery, and 9 physiological measures to determine allostatic load. The relationship among allostatic load, medical burden, and cognition was assessed. Compared with the mentally healthy comparators, patients were impaired globally, and in 4 cognitive domains-information-processing speed / executive functioning, delayed memory, language, and visuomotor ability, and presented with greater medical burden but not a different allostatic load. Allostatic load, but not medical burden, was associated with delayed memory performance both in a correlational analysis and in a multivariate regression analysis. Euthymic older patients with BD are impaired on several cognitive domains and have high medical burden. Their memory performance is more strongly associated with allostatic load than with traditional measures of medical burden. These findings need to be replicated and extended longitudinally. Copyright © 2017 John Wiley & Sons, Ltd.
Fernández-Ballesteros, Rocío; Bustillos, Antonio; Huici, Carmen
BACKGROUND/STUDY CONTEXT: The aim of this research is to explore whether segments of seniors might be immune to aging stereotypes of the older adult group. Stereotype threat research indicates that older adults show low memory recall under conditions of stereotype threat. Stereotype internalization theory (Levy, 2009) predicts that a positive perception of aging has favorable effects on the behavior and health of older people. A total of 112 older adult participants (62% women, aged 55 to 78) attending the University Programme for Older Adults were assigned to one of two conditions: stereotype threat condition and positive information condition. A control group was included from participants in the same program (n = 34; 61% women, aged 55 to 78). Individual differences in self-perception of aging were considered as continuous variable. Participants with better self-perception of aging showed better memory performance than those with poorer self-perception of aging in the stereotype threat condition and control condition. However, no differences were found in the positive information condition between participants with high and low self-perception of aging. These results indicate that positive self-perception of aging moderates the effects of stereotype threat, and that positive information promotes better memory performance for those older adults with a poorer self-perception of aging. As expected, individuals with a positive perception of their own aging were less vulnerable to the activation of a negative older adult stereotype in the stereotype threat condition.
Krause-Utz, A; Oei, N Y L; Niedtfeld, I; Bohus, M; Spinhoven, P; Schmahl, C; Elzinga, B M
Emotion dysregulation, characterized by heightened emotional arousal and increased emotional sensitivity, is a core feature of borderline personality disorder (BPD). Although current theories emphasize the disruptive potential of negative emotions on cognitive functioning in BPD, behavioral and neurobiological data on this relationship are still lacking. Using functional magnetic resonance imaging (fMRI), neural activity was investigated in 22 unmedicated BPD patients and 22 healthy participants (matched for age, education and intelligence) performing an adapted Sternberg working memory task, while being distracted by emotional (negatively arousing) and neutral pictures from the International Affective Picture System (IAPS). Emotional distraction was associated with significantly higher activation in the amygdala and decreased activation in the dorsolateral prefrontal cortex (DLPFC), extending findings of previous studies in healthy individuals. Patients with BPD showed significantly longer reaction times (RTs) along with significantly higher activation in the amygdala and insula during emotional distraction compared to healthy participants, suggesting that they were more distracted by emotional pictures during the working memory task. Moreover, in the group of BPD patients, a significant negative correlation was found between activation in limbic brain regions and self-reports of current dissociative states. Our findings suggest hyper-responsiveness to emotionally distracting pictures in BPD patients that negatively affects working memory performance. This stresses the importance of emotion dysregulation in the context of cognitive functioning. Moreover, our findings suggest that dissociative states have a dampening effect on neural reactivity during emotional challenge in BPD.
Sala-Llonch, Roser; Junqué, Carme; Arenaza-Urquijo, Eider M; Vidal-Piñeiro, Dídac; Valls-Pedret, Cinta; Palacios, Eva M; Domènech, Sara; Salvà, Antoni; Bargalló, Nuria; Bartrés-Faz, David
We used resting-functional magnetic resonance imaging data from 98 healthy older adults to analyze how local and global measures of functional brain connectivity are affected by age, and whether they are related to differences in memory performance. Whole-brain networks were created individually by parcellating the brain into 90 cerebral regions and obtaining pairwise connectivity. First, we studied age-associations in interregional connectivity and their relationship with the length of the connections. Aging was associated with less connectivity in the long-range connections of fronto-parietal and fronto-occipital systems and with higher connectivity of the short-range connections within frontal, parietal, and occipital lobes. We also used the graph theory to measure functional integration and segregation. The pattern of the overall age-related correlations presented positive correlations of average minimum path length (r = 0.380, p = 0.008) and of global clustering coefficients (r = 0.454, p memory functions. In conclusion, we found that older participants showed lower connectivity of long-range connections together with higher functional segregation of these same connections, which appeared to indicate a more local clustering of information processing. Higher local clustering in older participants was negatively related to memory performance. Copyright © 2014 Elsevier Inc. All rights reserved.
Fatemeh Bazzaz Monsef
Full Text Available Background and Objectives: Cognitive functions are one of the most important effective factors in students with dyscalculia. The present research aims to investigate the effectiveness of neurocognitive rehabilitation program on math performance and working memory of students with dyscalculia. Methods: This study was a quasi-experimental study with pretest-posttest design. Thirty elementary students with dyscalculia were selected using convenience sampling, and then the experimental and control groups (each 15 individuals, were matched in terms of age, gender, intelligence, and school grade. The subjects of the experimental group received twenty 45-minute sessions of neurocognitive rehabilitation. To collect the data, Wechsler Intelligence Scale (WISC-R test, Iran Key Math Diagnostic test, Digit Span test, Counting Span task, and Corsi Blocks task, were used. Results: In this study, the results of covariance analysis showed that the scores of the experimental group in working memory (digit span, counting span posttest and in Key-Math posttest, were higher than the control group. Conclusion: The results of this study is indicative of the effectiveness of cognitive rehabilitation in working memory (phonological loop, central executive and math performance (operation and applications in students with dyscalculia.
Full Text Available Genetic factors underlie a substantial proportion of individual differences in cognitive functions in humans, including processes related to episodic and working memory. While genetic association studies have proposed several candidate memory genes, these currently explain only a minor fraction of the phenotypic variance. Here, we performed genome-wide screening on 13 episodic and working memory phenotypes in 1,318 participants of the Berlin Aging Study II aged 60 years or older. The analyses highlight a number of novel single nucleotide polymorphisms (SNPs associated with memory performance, including one located in a putative regulatory region of microRNA (miRNA hsa-mir-138-5p (rs9882688, P-value = 7.8x10-9. Expression quantitative trait locus analyses on next-generation RNA-sequencing data revealed that rs9882688 genotypes show a significant correlation with the expression levels of this miRNA in 309 human lymphoblastoid cell lines (P-value = 5x10-4. In silico modeling of other top-ranking GWAS signals identified an additional memory-associated SNP in the 3' untranslated region (3'UTR of DCP1B, a gene encoding a core component of the mRNA decapping complex in humans, predicted to interfere with hsa-mir-138-5p binding. This prediction was confirmed in vitro by luciferase assays showing differential binding of hsa-mir-138-5p to 3'UTR reporter constructs in two human cell lines (HEK293: P-value = 0.0470; SH-SY5Y: P-value = 0.0866. Finally, expression profiling of hsa-mir-138-5p and DCP1B mRNA in human post-mortem brain tissue revealed that both molecules are expressed simultaneously in frontal cortex and hippocampus, suggesting that the proposed interaction between hsa-mir-138-5p and DCP1B may also take place in vivo. In summary, by combining unbiased genome-wide screening with extensive in silico modeling, in vitro functional assays, and gene expression profiling, our study identified miRNA-138 as a potential molecular regulator of human memory
Sampaio, J.; Cubukcu, M.; Cros, V.; Reyren, N., E-mail: email@example.com [Unité Mixte de Physique, CNRS, Thales, Univ. Paris-Sud, Université Paris-Saclay, 91767, Palaiseau (France); Khvalkovskiy, A. V. [Samsung Electronics, Semiconductor R& D Center (Grandis), San Jose, California 95134 (United States); Moscow Institute of Physics and Technology, State University, Moscow 141700 (Russian Federation); Kuteifan, M.; Lomakin, V. [Department of Electrical and Computer Engineering, University of California at San Diego, La Jolla, California 92093-0407 (United States); Apalkov, D. [Samsung Electronics, Semiconductor R& D Center (Grandis), San Jose, California 95134 (United States)
In order to increase the thermal stability of a magnetic random access memory cell, materials with high spin-orbit interaction are often introduced in the storage layer. As a side effect, a strong Dzyaloshinskii-Moriya interaction (DMI) may arise in such systems. Here, we investigate the impact of DMI on the magnetic cell performance, using micromagnetic simulations. We find that DMI strongly promotes non-uniform magnetization states and non-uniform switching modes of the magnetic layer. It appears to be detrimental for both the thermal stability of the cell and its switching current, leading to considerable deterioration of the cell performance even for a moderate DMI amplitude.
Hudetz, J A; Hudetz, A G; Klayman, J
This study tested the hypothesis that relaxation by guided imagery improves working-memory performance of healthy participants. 30 volunteers (both sexes, ages 17-56 years) were randomly assigned to one of three groups and administered the WAIS-III Letter-Number Sequencing Test before and after 10-min. treatment with guided imagery or popular music. The control group received no treatment. Groups' test scores were not different before treatment. The mean increased after relaxation by guided imagery but not after music or no treatment. This result supports the hypothesis that working-memory scores on the test are enhanced by guided imagery and implies that human information processing may be enhanced by prior relaxation.
Cody, Meghan W.; Teachman, Bethany A.
Despite predictions following from cognitive theories of anxiety, evidence for memory biases in social anxiety has been mixed. This study extends previous research by using stimuli relevant to participants’ concerns and allowing time for post-event processing. Participants high (n = 42) or low (n = 39) in social anxiety symptoms gave speeches and received standardized feedback on their and a confederate’s performance. Participants then took recognition and recall tests for the feedback immediately after it was given and after a two-day delay. Results showed no recall biases. However, the hypothesized recognition biases were found: the high social anxiety group remembered the confederate’s feedback more positively than their own, remembered their negative feedback as worse than the low group, and diminished positive feedback over time. Moreover, post-event processing mediated the relationship between social anxiety and memory for negative feedback. Results suggest that biased recognition of social feedback is linked to social anxiety. PMID:20399601
Gordon-Salant, Sandra; Cole, Stacey Samuels
This study aimed to determine if younger and older listeners with normal hearing who differ on working memory span perform differently on speech recognition tests in noise. Older adults typically exhibit poorer speech recognition scores in noise than younger adults, which is attributed primarily to poorer hearing sensitivity and more limited working memory capacity in older than younger adults. Previous studies typically tested older listeners with poorer hearing sensitivity and shorter working memory spans than younger listeners, making it difficult to discern the importance of working memory capacity on speech recognition. This investigation controlled for hearing sensitivity and compared speech recognition performance in noise by younger and older listeners who were subdivided into high and low working memory groups. Performance patterns were compared for different speech materials to assess whether or not the effect of working memory capacity varies with the demands of the specific speech test. The authors hypothesized that (1) normal-hearing listeners with low working memory span would exhibit poorer speech recognition performance in noise than those with high working memory span; (2) older listeners with normal hearing would show poorer speech recognition scores than younger listeners with normal hearing, when the two age groups were matched for working memory span; and (3) an interaction between age and working memory would be observed for speech materials that provide contextual cues. Twenty-eight older (61 to 75 years) and 25 younger (18 to 25 years) normal-hearing listeners were assigned to groups based on age and working memory status. Northwestern University Auditory Test No. 6 words and Institute of Electrical and Electronics Engineers sentences were presented in noise using an adaptive procedure to measure the signal-to-noise ratio corresponding to 50% correct performance. Cognitive ability was evaluated with two tests of working memory (Listening
Ducrocq, Emmanuel; Wilson, Mark; Smith, Tim J; Derakshan, Nazanin
Optimum levels of attentional control are essential to prevent athletes from experiencing performance breakdowns under pressure. The current study explored whether training attentional control using the adaptive dual n-back paradigm, designed to directly target processing efficiency of the main executive functions of working memory (WM), would result in transferrable effects on sports performance outcomes. A total of 30 tennis players were allocated to an adaptive WM training or active control group and underwent 10 days of training. Measures of WM capacity as well as performance and objective gaze indices of attentional control in a tennis volley task were assessed in low- and high-pressure posttraining conditions. Results revealed significant benefits of training on WM capacity, quiet eye offset, and tennis performance in the high-pressure condition. Our results confirm and extend previous findings supporting the transfer of cognitive training benefits to objective measures of sports performance under pressure.
Full Text Available Steroids are important neuromodulators influencing cognitive performance and synaptic plasticity. While the majority of literature concerns adrenal- and gonadectomized animals, very little is known about the natural endogenous release of hormones during learning. Therefore, we measured blood and brain (hippocampus, prefrontal cortex testosterone, estradiol, and corticosterone concentrations of intact male rats undergoing a spatial learning paradigm which is known to reinforce hippocampal plasticity. We found significant modulations of all investigated hormones over the training course. Corticosterone and testosterone were correlated manifold with behaviour, while estradiol expressed fewer correlations. In the recall session, testosterone was tightly coupled to reference memory performance, which is crucial for reinforcement of synaptic plasticity in the dentate gyrus. Intriguingly, prefrontal cortex and hippocampal levels related differentially to reference memory performance. Correlations of testosterone and corticosterone switched from unspecific activity to specific cognitive functions over training. Correspondingly, exogenous application of testosterone revealed different effects on synaptic and neuronal plasticity in trained versus untrained animals. While hippocampal long-term potentiation (LTP of the field excitatory postsynaptic potential (fEPSP was prolonged in untrained rats, both the fEPSP- and the population spike amplitude-LTP was impaired in trained rats. Behavioural performance was unaffected, but correlations of hippocampal field potentials with behaviour were decoupled in treated rats. The data provide important evidence that besides adrenal, also gonadal steroids play a mechanistic role in linking synaptic plasticity to cognitive performance.
Nishiura, Daisuke; Furuichi, Mikito; Sakaguchi, Hide
The computational performance of a smoothed particle hydrodynamics (SPH) simulation is investigated for three types of current shared-memory parallel computer devices: many integrated core (MIC) processors, graphics processing units (GPUs), and multi-core CPUs. We are especially interested in efficient shared-memory allocation methods for each chipset, because the efficient data access patterns differ between compute unified device architecture (CUDA) programming for GPUs and OpenMP programming for MIC processors and multi-core CPUs. We first introduce several parallel implementation techniques for the SPH code, and then examine these on our target computer architectures to determine the most effective algorithms for each processor unit. In addition, we evaluate the effective computing performance and power efficiency of the SPH simulation on each architecture, as these are critical metrics for overall performance in a multi-device environment. In our benchmark test, the GPU is found to produce the best arithmetic performance as a standalone device unit, and gives the most efficient power consumption. The multi-core CPU obtains the most effective computing performance. The computational speed of the MIC processor on Xeon Phi approached that of two Xeon CPUs. This indicates that using MICs is an attractive choice for existing SPH codes on multi-core CPUs parallelized by OpenMP, as it gains computational acceleration without the need for significant changes to the source code.
Ploetz, Danielle M; Mazur-Mosiewicz, Anya; Kirkwood, Michael W; Sherman, Elisabeth M S; Brooks, Brian L
Despite increasing interest in the use of performance validity tests with youth, relatively little is known about how children and adolescents with neurological diagnoses perform on these measures. The purpose of this study was to examine performance on the Test of Memory Malingering (TOMM) in a general pediatric neurologic sample. Data were obtained from 266 consecutive patients (mean age = 13.0, SD = 3.7, range = 5-18) referred for a neuropsychological assessment in a tertiary care pediatric hospital. As part of a broader neuropsychological battery, patients were administered the TOMM. In this sample, 94% of children passed the TOMM. Pass rate was 87% for 5-7 year-olds but was ≥ 90% for all other ages. Children with a history of stroke had the lowest pass rate (86%), with other diagnostic groups scoring ≥ 90%, including epilepsy, traumatic brain injury, and hydrocephalus. Lower TOMM performance was related to slower processing speed and weaker memory performance. The results support using the TOMM with children and adolescents who have neurological diagnoses. Caution may still be warranted when interpreting scores in those who are younger and/or who have more significant cognitive difficulty.
Full Text Available The goal of the study was to investigate the relationship between domain-general working memory capacity and domain-specific creativity amongst experienced soccer players. We administered the automated operation span task in combination with a domain-specific soccer creativity task to a group of 61 experienced soccer players to address the question whether an athlete’s domain-specific creativity is restricted by their domain-general cognitive abilities (i.e. working memory capacity. Given that previous studies have either found a positive correlation, a negative correlation, or no correlation between working memory capacity and creativity, we analyzed the data in an exploratory manner by following recent recommendations to report effect-size estimations and their precision in form of 95% confidence intervals. The pattern of results provided evidence that domain-general working memory capacity is not associated with creativity in a soccer-specific creativity task. This pattern of results suggests that future research and theorizing on the role of working memory in everyday creative performance needs to distinguish between different types of creative performance while also taking the role of domain-specific experience into account.
Furley, Philip; Memmert, Daniel
The goal of the study was to investigate the relationship between domain-general working memory capacity and domain-specific creativity amongst experienced soccer players. We administered the automated operation span task in combination with a domain-specific soccer creativity task to a group of 61 experienced soccer players to address the question whether an athlete's domain-specific creativity is restricted by their domain-general cognitive abilities (i.e., working memory capacity). Given that previous studies have either found a positive correlation, a negative correlation, or no correlation between working memory capacity and creativity, we analyzed the data in an exploratory manner by following recent recommendations to report effect-size estimations and their precision in form of 95% confidence intervals. The pattern of results provided evidence that domain-general working memory capacity is not associated with creativity in a soccer-specific creativity task. This pattern of results suggests that future research and theorizing on the role of working memory in everyday creative performance needs to distinguish between different types of creative performance while also taking the role of domain-specific experience into account.
Theppitak, Chalermsiri; Lai, Viet; Izumi, Hiroyuki; Higuchi, Yoshiyuki; Kumudini, Ganga; Movahed, Mehrnoosh; Kumashiro, Masaharu; Fujiki, Nobuhiro
Objectives: The aim of this study was to investigate whether the combination of extension of the encoding time and repetition of a test trial would improve the visual recognition memory performance in older adults. Methods...
Vanessa P. Rowe; Sébastien Lagacé; Katherine Guérard
The present study is a replication of Chum, Bekkering, Dodd, and Pratt (2007). Motor and visual codes interact to facilitate visuospatial memory performance. Psychonomic Bulletin & Review, 14, 1189-1193.
Vanessa P. Rowe
Full Text Available The present study is a replication of Chum, Bekkering, Dodd, and Pratt (2007. Motor and visual codes interact to facilitate visuospatial memory performance. Psychonomic Bulletin & Review, 14, 1189-1193.
Ackermann, Sandra; Heck, Angela; Rasch, Björn; Papassotiropoulos, Andreas; de Quervain, Dominique J-F
Glucocorticoids, stress hormones released from the adrenal cortex, are important players in the regulation of emotional memory. Specifically, in animals and in humans, glucocorticoids enhance memory consolidation of emotionally arousing experiences, but impair memory retrieval. These glucocorticoid actions are partly mediated by glucocorticoid receptors in the hippocampus, amygdala and prefrontal cortex, key brain regions for emotional memory. In a recent study in patients who underwent cardiac surgery, the BclI polymorphism of the glucocorticoid receptor gene (NR3C1) was associated with traumatic memories and posttraumatic stress disorder symptoms after intensive care therapy. Based on this finding, we investigated if the BclI polymorphism is also associated with emotional memory in healthy young subjects (N=841). We used a picture-learning task consisting of learning and recalling neutral and emotional photographs on two consecutive days. The BclI variant was associated with short-delay recall of emotional pictures on both days, with GG carriers showing increased emotional memory performance as compared to GC and CC carriers. We did not detect a genotype-dependent difference in recall performance for neutral pictures. These findings suggest that the Bcll polymorphism contributes to inter-individual differences in emotional memory also in healthy humans. Copyright © 2012 Elsevier Ltd. All rights reserved.
Kuschpel, Maxim S.; Liu, Shuyan; Schad, Daniel J.; Heinzel, Stephan; Heinz, Andreas; Rapp, Michael A.
The interruption of learning processes by breaks filled with diverse activities is common in everyday life. We investigated the effects of active computer gaming and passive relaxation (rest and music) breaks on working memory performance. Young adults were exposed to breaks involving (i) eyes-open resting, (ii) listening to music and (iii) playing the video game “Angry Birds” before performing the n-back working memory task. Based on linear mixed-effects modeling, we found that playing the “...
Kline, Julia E; Poggensee, Katherine; Ferris, Daniel P
When humans walk in everyday life, they typically perform a range of cognitive tasks while they are on the move. Past studies examining performance changes in dual cognitive-motor tasks during walking have produced a variety of results. These discrepancies may be related to the type of cognitive task chosen, differences in the walking speeds studied, or lack of controlling for walking speed. The goal of this study was to determine how young, healthy subjects performed a spatial working memory task over a range of walking speeds. We used high-density electroencephalography to determine if electrocortical activity mirrored changes in cognitive performance across speeds. Subjects stood (0.0 m/s) and walked (0.4, 0.8, 1.2, and 1.6 m/s) with and without performing a Brooks spatial working memory task. We hypothesized that performance of the spatial working memory task and the associated electrocortical activity would decrease significantly with walking speed. Across speeds, the spatial working memory task caused subjects to step more widely compared with walking without the task. This is typically a sign that humans are adapting their gait dynamics to increase gait stability. Several cortical areas exhibited power fluctuations time-locked to memory encoding during the cognitive task. In the somatosensory association cortex, alpha power increased prior to stimulus presentation and decreased during memory encoding. There were small significant reductions in theta power in the right superior parietal lobule and the posterior cingulate cortex around memory encoding. However, the subjects did not show a significant change in cognitive task performance or electrocortical activity with walking speed. These findings indicate that in young, healthy subjects walking speed does not affect performance of a spatial working memory task. These subjects can devote adequate cortical resources to spatial cognition when needed, regardless of walking speed.
Forkstam, Christian; Petersson, Karl Magnus
The human brain supports acquisition mechanisms that can extract structural regularities implicitly from experience without the induction of an explicit model. Reber defined the process by which an individual comes to respond appropriately to the statistical structure of the input ensemble as implicit learning. He argued that the capacity to generalize to new input is based on the acquisition of abstract representations that reflect underlying structural regularities in the acquisition input. We focus this review of the implicit learning literature on studies published during 2004 and 2005. We will not review studies of repetition priming ('implicit memory'). Instead we focus on two commonly used experimental paradigms: the serial reaction time task and artificial grammar learning. Previous comprehensive reviews can be found in Seger's 1994 article and the Handbook of Implicit Learning. Emerging themes include the interaction between implicit and explicit processes, the role of the medial temporal lobe, developmental aspects of implicit learning, age-dependence, the role of sleep and consolidation. The attempts to characterize the interaction between implicit and explicit learning are promising although not well understood. The same can be said about the role of sleep and consolidation. Despite the fact that lesion studies have relatively consistently suggested that the medial temporal lobe memory system is not necessary for implicit learning, a number of functional magnetic resonance studies have reported medial temporal lobe activation in implicit learning. This issue merits further research. Finally, the clinical relevance of implicit learning remains to be determined.
Jiang, Caihong; Rau, Pei-Luen Patrick
Using event-related potentials (ERPs), we examined the time course of 39 healthy novice drivers during a blocked working memory task (numerical N-back) under acute social stress or control conditions, which were induced by the Trier Social Stress Task (TSST) or control procedure. Subjective measures were used to assess stress manipulation throughout the experiment. An elevated negative effect in response to a stress condition indicated a successful stress induction. The behavioral results showed that the stress group had a longer response time and larger differences in accuracy than the control group. On a neural level, the control group had larger P3 amplitude in the 1-back condition than in the 2-back condition; this load effect, however, disappeared in the stress group. These results revealed that acute social stress had a disruptive effect on both working memory behavioral performance and cognitive neural process. These findings provide us with a basis to understand the correlation between acute stress and cognitive processes of working memory at a cognitive neural level. Copyright © 2017 Elsevier B.V. All rights reserved.
Casoli, Tiziana; Di Stefano, Giuseppina; Fattoretti, Patrizia; Giorgetti, Belinda; Balietti, Marta; Lattanzio, Fabrizia; Aicardi, Giorgio; Platano, Daniela
Previous studies have shown that messenger RNA (mRNA) of the dynamin-binding protein (DNMBP), a scaffold protein regulating actin cytoskeleton and synaptic vesicle pools, is lower in neuropathologically-confirmed Alzheimer's brains. Here we investigated whether a deficit in long term memory formation during physiological aging is also associated with lower DNMBP expression. Hippocampal DNMBP mRNA was quantified by quantitative real time reverse transcriptase polymerase chain reaction (qRT-PCR) following inhibitory avoidance task in aged (26- to 27-month-old) rats that, according to memory performance, were ranked as good responders (GR) and bad responders (BR), in adult (3-month-old), late-adult (19-month-old), and aged (26-27-month-old) naive animals. We found that DNMBP mRNA levels were significantly higher in naive adults versus late adult and aged naive rats, in GR versus BR, and in pooled GR and BR versus aged-matched controls. Our data provide the first evidence that hippocampal DNMBP mRNA expression is reduced during physiological aging, and suggest that the capability to increase the expression of this mRNA may be a requirement for preserving long term memory formation during aging. Copyright © 2012 Elsevier Inc. All rights reserved.
Gordon, Evan M; Stollstorff, Melanie; Vaidya, Chandan J
Many researchers have noted that the functional architecture of the human brain is relatively invariant during task performance and the resting state. Indeed, intrinsic connectivity networks (ICNs) revealed by resting-state functional connectivity analyses are spatially similar to regions activated during cognitive tasks. This suggests that patterns of task-related activation in individual subjects may result from the engagement of one or more of these ICNs; however, this has not been tested. We used a novel analysis, spatial multiple regression, to test whether the patterns of activation during an N-back working memory task could be well described by a linear combination of ICNs delineated using Independent Components Analysis at rest. We found that across subjects, the cingulo-opercular Set Maintenance ICN, as well as right and left Frontoparietal Control ICNs, were reliably activated during working memory, while Default Mode and Visual ICNs were reliably deactivated. Further, involvement of Set Maintenance, Frontoparietal Control, and Dorsal Attention ICNs was sensitive to varying working memory load. Finally, the degree of left Frontoparietal Control network activation predicted response speed, while activation in both left Frontoparietal Control and Dorsal Attention networks predicted task accuracy. These results suggest that a close relationship between resting-state networks and task-evoked activation is functionally relevant for behavior, and that spatial multiple regression analysis is a suitable method for revealing that relationship. Copyright © 2011 Wiley-Liss, Inc.
Passolunghi, Maria C; Caviola, Sara; De Agostini, Ruggero; Perin, Chiara; Mammarella, Irene C
Mathematics anxiety (MA) has been defined as "a feeling of tension and anxiety that interferes with the manipulation of numbers and the solving of math problems in a wide variety of ordinary life and academic situations." Previous studies have suggested that a notable proportion of children in primary and secondary school suffer from MA, which is negatively correlated with calculation skills. The processing efficiency and attentional control theories suggest that working memory (WM) also plays an important part in such anxious feelings. The present study aimed to analyze the academic achievement and cognitive profiles of students with high math anxiety (HMA) and low math anxiety (LMA). Specifically, 32 students with HMA and 34 with LMA matched for age, gender, generalized anxiety, and vocabulary attending sixth to eighth grades were selected from a larger sample. The two groups were tested on reading decoding, reading comprehension, mathematics achievement, and on verbal short-term memory and WM. Our findings showed that HMA students were weak in several measures of mathematics achievement, but not in reading and writing skills, and that students with HMA reported lower scores on short-term memory and WM performances (with associated difficulties in inhibiting irrelevant information) than children with LMA. In addition, a logistic regression showed that weaknesses in inhibitory control and fact retrieval were the strongest variables for classifying children as having HMA or LMA.
Maria Chiara ePassolunghi
Full Text Available Mathematics anxiety (MA has been defined as a feeling of tension and anxiety that interferes with the manipulation of numbers and the solving of math problems in a wide variety of ordinary life and academic situations. Previous studies have suggested that a notable proportion of children in primary and secondary school suffer from MA, which is negatively correlated with calculation skills. The processing efficiency and attentional control theories suggest that working memory (WM also plays an important part in such anxious feelings.The present study aimed to analyze the academic achievement and cognitive profiles of students with high math anxiety (HMA and low math anxiety (LMA. Specifically, 32 students with HMA and 34 with LMA matched for age, gender, generalized anxiety, and vocabulary attending sixth to eighth grades were selected from a larger sample. The two groups were tested on reading decoding, reading comprehension, mathematics achievement, and on verbal short-term memory and WM. Our findings showed that HMA students were weak in several measures of mathematics achievement, but not in reading and writing skills, and that students with HMA reported lower scores on short-term memory and WM performances (with associated difficulties in inhibiting irrelevant information than children with LMA. In addition, a logistic regression showed that weaknesses in inhibitory control and fact retrieval were the strongest variables for classifying children as having HMA or LMA.
Gordon, Evan M.; Stollstorff, Melanie; Vaidya, Chandan J.
Many researchers have noted that the functional architecture of the human brain is relatively invariant during task performance and the resting state. Indeed, intrinsic connectivity networks (ICNs) revealed by resting-state functional connectivity analyses are spatially similar to regions activated during cognitive tasks. This suggests that patterns of task-related activation in individual subjects may result from the engagement of one or more of these ICNs; however, this has not been tested. We used a novel analysis, spatial multiple regression, to test whether the patterns of activation during an N-back working memory task could be well described by a linear combination of ICNs delineated using Independent Components Analysis at rest. We found that across subjects, the cingulo-opercular Set Maintenance ICN, as well as right and left Frontoparietal Control ICNs, were reliably activated during working memory, while Default Mode and Visual ICNs were reliably deactivated. Further, involvement of Set Maintenance, Frontoparietal Control, and Dorsal Attention ICNs was sensitive to varying working memory load. Finally, the degree of left Frontoparietal Control network activation predicted response speed, while activation in both left Frontoparietal Control and Dorsal Attention networks predicted task accuracy. These results suggest that a close relationship between resting-state networks and task-evoked activation is functionally relevant for behavior, and that spatial multiple regression analysis is a suitable method for revealing that relationship. PMID:21761505
Full Text Available Transcranial direct current stimulation (tDCS has been put forward as a non-pharmacological alternative for alleviating cognitive decline in old age. Although results have shown some promise, little is known about the optimal stimulation parameters for modulation in the cognitive domain. In this study, the effects of tDCS over the dorsolateral prefrontal cortex (dlPFC on working memory performance were investigated in thirty older adults. An N-back task assessed working memory before, during and after anodal tDCS at a current strength of 1mA and 2mA, in addition to sham stimulation. The study used a single-blind, cross-over design. The results revealed no significant effect of tDCS on accuracy or response times during or after stimulation, for any of the current strengths. These results suggest that a single session of tDCS over the dlPFC is unlikely to improve working memory, as assessed by an N-back task, in old age.
Leer, Arne; Engelhard, Iris M; Lenaert, Bert; Struyf, Dieter; Vervliet, Bram; Hermans, Dirk
Eye Movement Desensitization and Reprocessing (EMDR) therapy for posttraumatic stress disorder involves making eye movements (EMs) during recall of a traumatic image. Experimental studies have shown that the dual task decreases self-reported memory vividness and emotionality. However valuable, these data are prone to demand effects and little can be inferred about the mechanism(s) underlying the observed effects. The current research aimed to fill this lacuna by providing two objective tests of memory performance. Experiment I involved a stimulus discrimination task. Findings were that EM during stimulus recall not only reduces self-reported memory vividness, but also slows down reaction time in a task that requires participants to discriminate the stimulus from perceptually similar stimuli. Experiment II involved a fear conditioning paradigm. It was shown that EM during recall of a threatening stimulus intensifies fearful responding to a perceptually similar yet non-threat-related stimulus, as evidenced by increases in danger expectancies and skin conductance responses. The latter result was not corroborated by startle EMG data. Together, the findings suggest that the EM manipulation renders stimulus attributes less accessible for future recall. Copyright © 2017 Elsevier Ltd. All rights reserved.
Sohel, Nazmul; Tuokko, Holly; Griffith, Lauren; Raina, Parminder
the objectives of this study were: (i) to estimate the rate of discrepancy between participant single-item self-reports of good memory and poor performance on a list-learning task and (ii) to identify the factors including age, gender and health status that influence these discrepant classifications. in total, 14,172 individuals, aged 45-85, were selected from the 2008-09 Canadian Community Health Survey on Healthy Aging. We examined the individual characteristics of participants with and without discrepancies between memory self-reports and performance with a generalised linear model, adjusting for potential covariates. the mean age of respondents was 62.9 years with 56.7% being female, 53.8% having post-secondary graduation and 83% being born in Canada. Higher discrepant classification rates we observed for younger people (6.77 versus 3.65 for lowest and highest group), female (5.90 versus 3.68) and with higher education (6.17 versus 3.52). Discrepant classification rates adjusted with all covariates were higher for those without chronic diseases (5.37 [95% Confidence Interval (CI): 4.16, 6.90] versus 4.05 95% CI: 3.38, 4.86; P = 0.0127), those who did not drink alcohol (5.87 95% CI: 4.69, 7.32 versus 3.70 95% CI: 3.00, 4.55; P memory and memory performance differ in a substantial proportion of the population. Therefore, relying on a self-reported memory status may not accurately capture those experiencing memory difficulties. © The Author 2015. Published by Oxford University Press on behalf of the British Geriatrics Society. All rights reserved. For Permissions, please email: firstname.lastname@example.org.
O'Callaghan, Michael J.
The principles underlying optical correlators and Fourier transform optical memories are well understood. The components and materials they depend upon are gradually becoming available, bringing these technologies closer to commercialization. As efforts are made to obtain the best possible performance from these systems it becomes increasingly important to understand how their detailed operation differs from simple idealized models. Spatial light modulators (SLMs) used in correlators display sets of discrete data rather than continuous 2D functions, and the optical Fourier transform of these SLMs is influenced by the shape and fill-factor of the SLM's pixels. As a consequence, optical correlators perform a function that is more complex than the simple idealized correlation operation. The performance of Fourier transform optical memories is similarly affected. Here we investigate the operation of such optical systems incorporating pixelated SLMs. Examples are presented which highlight differences between the functions actually performed by these systems and the simple conceptual models of their operation. The output of these systems is commonly detected using pixelated CCD or CMOS imagers, the effect of imager pixel fill-factor is also examined.
Full Text Available Kopiez et al. (this volume empirically investigated the effect of playing from memory (more specifically, playing with a conspicuously visible music stand on the evaluation of audiovisual recordings of solo instrumental performances. Their study, a replication of Williamon (1999, corroborates the finding that the presence of a music stand has a small but significant negative effect on performance evaluations. In this commentary, I present some possible explanations for this effect and discuss relevant implications for future research and for professional performers. I also provide some suggestions for improving the experimental design, such as using a better measure of musical sophistication, controlling for the potential visual distractor effect of the music stand, and developing a more comprehensive and statistically robust scale for evaluating performances.
Nespollo, Alice Milani; Marcon, Samira Reschetti; Lima, Nathalie Vilma Pollo de; Dias, Tatiane Lebre; Espinosa, Mariano Martínez
to verify the correlation between health condition and memory performance of older adult women in the community. Analytical cross-sectional study developed with 28 older adult women living in Cuiabá-MT. They answered the Mini-Mental State Examination (MMSE), and a shortened Geriatric Depression Scale (GDS-15) to screen for dementia and depression symptoms. Memory skills were assessed through Rey Auditory Verbal Learning Test (RAVLT). The mean age was 66.36 years and 75% of the participants had educational level higher than 7 years. The MMSE mean score was 28.45. The correlations found were: educational level and immediate memory (r = 0.49; p = 0.008); delayed recall and immediate memory (r = 0.71; p habilidades de memória ocorreu por meio do Teste de Aprendizagem Auditivo-Verbal de Rey (RAVLT). A idade média foi de 66,36 anos e 75% possuíam escolaridade maior que sete anos. A média do MEEM foi 28,45. As correlações encontradas foram: escolaridade e memória imediata (r = 0,49; p = 0,008); evocação tardia e memória de reconhecimento com memória imediata (r = 0,71; p < 0,001 e r = 0,43; p = 0,021) e memória de reconhecimento com evocação tardia (r = 0,47; p = 0,012). Evidenciou-se escore elevado no MEEM e percepção de saúde satisfatória entre os participantes. Não houve correlação entre desempenho da memória e percepção de saúde.
Studte, Sara; Bridger, Emma; Mecklinger, Axel
The consolidation of new associations is thought to depend in part on physiological processes engaged during non-REM (NREM) sleep, such as slow oscillations and sleep spindles. Moreover, NREM sleep is thought to selectively benefit associations that are adaptive for the future. In line with this, the current study investigated whether different reward cues at encoding are associated with changes in sleep physiology and memory retention. Participants' associative memory was tested after learning a list of arbitrarily paired words both before and after taking a 90-min nap. During learning, word-pairs were preceded by a cue indicating either a high or a low reward for correct memory performance at test. The motivation manipulation successfully impacted retention such that memory declined to a greater extent from pre- to post sleep for low rewarded than for high rewarded word-pairs. In line with previous studies, positive correlations between spindle density during NREM sleep and general memory performance pre- and post-sleep were found. In addition to this, however, a selective positive relationship between memory performance for highly rewarded word-pairs at posttest and spindle density during NREM sleep was also observed. These results support the view that motivationally salient memories are preferentially consolidated and that sleep spindles may be an important underlying mechanism for selective consolidation. Copyright © 2016 Elsevier Inc. All rights reserved.
Shen, J; Zhang, G; Yao, L; Zhao, X
Working memory refers to the ability to temporarily store and manipulate information that is necessary for complex cognition activities. Previous studies have demonstrated that working memory capacity can be improved by behavioral training, and brain activities in the frontal and parietal cortices and the connections between these regions are also altered by training. Our recent neurofeedback training has proven that the regulation of the left dorsal lateral prefrontal cortex (DLPFC) activity using real-time functional magnetic resonance imaging (rtfMRI) can improve working memory performance. However, how working memory training promotes interaction between brain regions and whether this promotion correlates with performance improvement remain unclear. In this study, we employed structural equation modeling (SEM) to calculate the interactions between the regions within the working memory network during neurofeedback training. The results revealed that the direct effect of the frontoparietal connection in the left hemisphere was enhanced by the rtfMRI training. Specifically, the increase in the path from the left DLPFC to the left inferior parietal lobule (IPL) was positively correlated with improved performance in verbal working memory. These findings demonstrate the important role of the frontoparietal connection in working memory training and suggest that increases in frontoparietal connectivity might be a key factor associated with behavioral improvement. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.
Resmini, Eugenia; Santos, Alicia; Gómez-Anson, Beatriz; Vives, Yolanda; Pires, Patricia; Crespo, Iris; Portella, Maria J; de Juan-Delago, Manel; Barahona, Maria-José; Webb, Susan M
Cushing's syndrome (CS) affects cognition and memory. Our objective was to evaluate memory and hippocampal volumes (HV) on 3-tesla magnetic resonance imaging (3T MRI) in CS patients and controls. Thirty-three CS patients (11 active, 22 cured) and 34 controls matched for age, sex, and education underwent Rey Auditory Verbal Learning Test and Rey-Osterrieth Complex Figure memory tests. Gray matter and HV were calculated on 3T MRI, using FreeSurfer image analyses software. No differences in HV were observed between active and cured CS or controls. Memory performance was worse in CS patients than controls (P verbal (P = 0.02) and visual memory (P = 0.04) than controls. In 12 CS patients, memory was below normative cutoff values for verbal (n = 6, cured), visual memory (n = 10, six cured) or both (n = 4); these patients with severe memory impairments showed smaller HV compared with their matched controls (P = 0.02 with verbal impairment; P = 0.03 with visual impairment). They were older (P = 0.04), had shorter education (P = 0.02), and showed a trend toward longer duration of hypercortisolism (P = 0.07) than the remaining CS patients. Total (P = 0.004) and cortical (P = 0.03) brain gray matter volumes were decreased in CS compared with controls, indicating brain atrophy, whereas subcortical gray matter (which includes HV) was reduced only in the 12 patients with severe memory impairment. Verbal and visual memory is worse in CS patients than controls, even after biochemical cure. HV was decreased only in those whose memory scores were below normative cutoff values.
Full Text Available The existence of structural, control, and data hazards presents a major challenge in designing an advanced pipeline/superscalar microprocessor. An efficient memory hierarchy cache-RAM-Disk design greatly enhances the microprocessor's performance. However, there are complex relationships among the memory hierarchy and the functional units in the microprocessor. Most past architectural design simulations focus on the instruction hazard detection/prevention scheme from the viewpoint of function units. This paper emphasizes that additional inboard memory can be well utilized to handle the hazardous conditions. When the instruction meets hazardous issues, the memory latency can be utilized to prevent performance degradation due to the hazard prevention mechanism. By using the proposed technique, a better architectural design can be rapidly validated by an FPGA at the start of the design stage. In this paper, the simulation results prove that our proposed methodology has a better performance and less power consumption compared to the conventional hazard prevention technique.
Full Text Available Working memory is sensitive to aging-related decline. Evidence exists that aging is accompanied by a reorganization of the working-memory circuitry, but the underlying neurocognitive mechanisms are unclear. In this study, we examined aging-related changes in prefrontal activation during working-memory performance using functional Near-Infrared Spectroscopy (fNIRS, a noninvasive neuroimaging technique. Seventeen healthy young (21-32 years and 17 healthy older adults (64-81 years performed a verbal working-memory task (n-back. Oxygenated and deoxygenated hemoglobin concentration changes were registered by two fNIRS channels located over the left and right prefrontal cortex. Increased working-memory load resulted in worse performance compared to the control condition in older adults, but not in young participants. In both young and older adults, prefrontal activation increased with rising working-memory load. Young adults showed slight right-hemispheric dominance at low levels of working-memory load, while no hemispheric differences were apparent in older adults. Analysis of the time-activation curve during the high working-memory load condition revealed a continuous increase of the hemodynamic response in the young. In contrast to that, a quadratic pattern of activation was found in the older participants. Based on these results it could be hypothesized that young adults were better able to keep the prefrontal cortex recruited over a prolonged period of time. To conclude, already at low levels of working-memory load do older adults recruit both hemispheres, possibly in an attempt to compensate for the observed aging-related decline in performance. Also, our study shows that aging effects on the time course of the hemodynamic response must be taken into account in the interpretation of the results of neuroimaging studies that rely on blood oxygen levels, such as fMRI.
Taub, J M
Effects of habitual variations in napping on psychomotor performance, short-term memory and subjective states were investigated. The subjects were 32 healthy male university students who napped twice or more weekly in themorning and at night. Sixteen were randomly assigned to a control group and 16 to a nap(treatment) group. The experiment comprised two conditions of electrographically (EEG) recorded sleep for the nap group and two EEG monitored conditions of wakefulness for the controls. These conditions were scheduled from 9:35 to 11:35 a.m. and 12 hr later between 9:35 p.m. and 11:35 p.m. Measurements were obtained from: (a) a continuous 10-min auditory reaction time task, (b) a free recall task of short-term memory, (c) an activation-mood adjective check list, and (d) the Stanford Sleepiness scale. Except for memory the dependent variables of waking function were assessed 20 min before and 20 min after all conditions. Following each sleep condition the nap group as opposed to the controls showed a statistically significant improvement in reaction time performance, higher short-term retention, less reported sleepiness and elevated subjective states reflected by fice factors on the adjective mood-activation check list. Among the correlations computed the largest significant coefficients were of stage 4 and REM with posttreatment Stanford Sleepiness ratings. After naps, increased postdormital sleepiness was correlated with stage 4 and decreased sleepiness with REM sleep. Although few strikingly divergent functional effects were associated with morning and nocturanal naps, these did covary with sleep psychophysiology. It is postulated that the phase, the EEG-sleep stages and possibly the duration of accustomed naps are less salient factors influencing performance when the time since awakening until behavioral assessment can be kept constant.
Vestergaard, Martin; Madsen, Kathrine Skak; Baaré, William F C
During childhood and adolescence, ongoing white matter maturation in the fronto-parietal cortices and connecting fiber tracts is measurable with diffusion-weighted imaging. Important questions remain, however, about the links between these changes and developing cognitive functions. Spatial working...... memory (SWM) performance improves significantly throughout the childhood years, and several lines of evidence implicate the left fronto-parietal cortices and connecting fiber tracts in SWM processing. Here we report results from a study of 76 typically developing children, 7 to 13 years of age. We...
Mesripour, Azadeh; Moghimi, Fatemeh; Rafieian-Kopaie, Mahmoud
Cinnamomum zeylanicum (cinnamon) has a wide range of beneficial effects including mild glucose lowering activity. The aim of the present study was to investigate whether cinnamon bark extract has the potential to improve memory performance and glucose profiles in diabetic mice. Memory was assessed by the novel object recognition task in male Balb/c mice. In this method, the difference between exploration time of a familiar object and a novel object was considered as an index of memory performance (recognition index, RI). The water extract was prepared by boiling cinnamon bark for 15 min. Alloxan induced diabetes in animals (serum glucose levels were 322 ± 7.5 mg/dL), and also impaired memory performance (RI= -3.3% ± 3.3) which differed significantly from control animals (RI = 32% ± 6.5). Although treatment with cinnamon only reduced fasting blood glucose level moderately but it improved memory performance remarkably (RI = 25.5% ± 5.6). Oxidative stress following administration of cinnamon extract was lower in diabetic mice. It was concluded that cinnamon water extract could be a useful alternative medicine in diabetic patients' daily regimen which not only reduces blood glucose levels but also improves memory performance and lipid peroxidation level.
The article proposes an approach, broadly inspired by culturally inclusive pedagogy, to facilitate international student academic adaptation based on rendering tacit aspects of local learning cultures explicit to international full degree students, rather than adapting them. Preliminary findings...... are presented from a focus group-based exploratory study of international student experiences at different stages of their studies at a Danish business school, one of Denmark’s most international universities. The data show how a major source of confusion for these students has to do with the tacit logics...... and expectations that shape how the formal steps of the learning cycle are understood and enacted locally, notably how learning and assessment moments are defined and related to one another. Theoretically, the article draws on tacit knowledge and sense-making theories to analyse student narratives...
Imam, Neena [ORNL; Humble, Travis S. [ORNL; McCaskey, Alex [ORNL; Schrock, Jonathan [ORNL; Hamilton, Kathleen E. [ORNL
A content-addressable memory (CAM) stores key-value associations such that the key is recalled by providing its associated value. While CAM recall is traditionally performed using recurrent neural network models, we show how to solve this problem using adiabatic quantum optimization. Our approach maps the recurrent neural network to a commercially available quantum processing unit by taking advantage of the common underlying Ising spin model. We then assess the accuracy of the quantum processor to store key-value associations by quantifying recall performance against an ensemble of problem sets. We observe that different learning rules from the neural network community influence recall accuracy but performance appears to be limited by potential noise in the processor. The strong connection established between quantum processors and neural network problems supports the growing intersection of these two ideas.
Full Text Available The goal of this study is to investigate the role of working memory capacity in L2 attainment and performance. The study uses an L1 reading span task to measure working memory of a group of 59 high- intermediate/advanced learners of English, and a film retelling task to measure their oral production. The analysis first showed a moderate to high correlation between proficiency measured by a general proficiency test and learners’ fluency, lexical complexity, and accuracy but not structural complexity on the retelling task. Secondly, no correlation was found between overall proficiency and working memory. Thirdly, a weak correlation was found between fluency and lexical complexity, and working memory. When the group was split into top and bottom levels of proficiency, moderate correlations were found between lexical complexity and working memory only for the high-proficiency group. The results are discussed in the light of previous research.El objetivo de este estudio es investigar el rol de la capacidad de memoria operativa en la proficiencia y la producción en una L2. El estudio utiliza una tarea de reading span en la L1 para medir la memoria operativa de un grupo de 59 estudiantes de inglés de nivel intermedio alto/avanzado, y una tarea narrativa para medir su producción oral. Los análisis muestran correlaciones significativas entre la proficiencia medida por un test de proficiencia general y la fluidez, complejidad léxica, y corrección, aunque no con la complejidad estructural. Las correlaciones también son positivas y significativas entre la memoria operativa y la fluidez y complejidad léxica, pero no se observa una correlación significativa entre la proficiencia general y la memoria operativa. Cuando se divide el grupo entre los niveles más altos y más bajos se encuentran correlaciones moderadas entre la complejidad léxica y la memoria operativa sólo para el grupo de proficiencia alta. Los resultados se analizan en base a los
Ihne, Jessica L; Gallagher, Natalie M; Sullivan, Marie; Callicott, Joseph H; Green, Adam E
Perhaps the most widely studied effect to emerge from the combination of neuroimaging and human genetics is the association of the COMT-Val(108/158)Met polymorphism with prefrontal activity during working memory. COMT-Val is a putative risk factor in schizophrenia, which is characterized by disordered prefrontal function. Work in healthy populations has sought to characterize mechanisms by which the valine (Val) allele may lead to disadvantaged prefrontal cognition. Lower activity in methionine (Met) carriers has been interpreted as advantageous neural efficiency. Notably, however, studies reporting COMT effects on neural efficiency have generally not reported working memory performance effects. Those studies have employed relatively low/easy working memory loads. Higher loads are known to elicit individual differences in working memory performance that are not visible at lower loads. If COMT-Met confers greater neural efficiency when working memory is easy, a reasonable prediction is that Met carriers will be better able to cope with increasing demand for neural resources when working memory becomes difficult. To our knowledge, this prediction has thus far gone untested. Here, we tested performance on three working memory tasks. Performance on each task was measured at multiple levels of load/difficulty, including loads more demanding than those used in prior studies. We found no genotype-by-load interactions or main effects of COMT genotype on accuracy or reaction time. Indeed, even testing for performance differences at each load of each task failed to find a single significant effect of COMT genotype. Thus, even if COMT genotype has the effects on prefrontal efficiency that prior work has suggested, such effects may not directly impact high-load working memory ability. The present findings accord with previous evidence that behavioral effects of COMT are small or nonexistent and, more broadly, with a growing consensus that substantial effects on phenotype will
Bailey, Jennifer A; Penhune, Virginia B
Behavioural and neuroimaging studies provide evidence for a possible "sensitive" period in childhood development during which musical training results in long-lasting changes in brain structure and auditory and motor performance. Previous work from our laboratory has shown that adult musicians who begin training before the age of 7 (early-trained; ET) perform better on a visuomotor task than those who begin after the age of 7 (late-trained; LT), even when matched on total years of musical training and experience. Two questions were raised regarding the findings from this experiment. First, would this group performance difference be observed using a more familiar, musically relevant task such as auditory rhythms? Second, would cognitive abilities mediate this difference in task performance? To address these questions, ET and LT musicians, matched on years of musical training, hours of current practice and experience, were tested on an auditory rhythm synchronization task. The task consisted of six woodblock rhythms of varying levels of metrical complexity. In addition, participants were tested on cognitive subtests measuring vocabulary, working memory and pattern recognition. The two groups of musicians differed in their performance of the rhythm task, such that the ET musicians were better at reproducing the temporal structure of the rhythms. There were no group differences on the cognitive measures. Interestingly, across both groups, individual task performance correlated with auditory working memory abilities and years of formal training. These results support the idea of a sensitive period during the early years of childhood for developing sensorimotor synchronization abilities via musical training.
Trikojat, K; Buske-Kirschbaum, A; Plessow, F; Schmitt, J; Fischer, R
In previous research, patients with seasonal allergic rhinitis (SAR) showed poorer school and work performance during periods of acute allergic inflammation, supporting the idea of an impact of SAR on cognitive functions. However, the specific cognitive domains particularly vulnerable to inflammatory processes are unclear. In this study, the influence of SAR on memory and multitasking performance, as two potentially vulnerable cognitive domains essential in everyday life functioning, was investigated in patients with SAR. Non-medicated patients with SAR (n = 41) and healthy non-allergic controls (n = 42) performed a dual-task paradigm and a verbal learning and memory test during and out of symptomatic allergy periods (pollen vs. non-pollen season). Disease-related factors (e.g. symptom severity, duration of symptoms, duration of disease) and allergy-related quality of life were evaluated as potential influences of cognitive performance. During the symptomatic allergy period, patients showed (1) poorer performance in word list-based learning (P = 0.028) and (2) a general slowing in processing speed (P multitasking. Yet, typical parameters indicating specific multitasking costs were not affected. A significant negative association was found between learning performance and duration of disease (r = -0.451, P = 0.004), whereas symptom severity (r = 0.326; P = 0.037) and quality of life (r = 0.379; P = 0.015) were positively associated with multitasking strategy. Our findings suggest that SAR has a differentiated and complex impact on cognitive functions, which should be considered in the management of SAR symptoms. They also call attention to the importance of selecting sensitive measures and carefully interpreting cognitive outcomes. © 2017 John Wiley & Sons Ltd.
Full Text Available BACKGROUND: Sleep facilitates off-line consolidation of memories, as shown for learning of motor skills in the absence of concomitant distractors. We often perform complex tasks focusing our attention mostly on one single part of them. However, we are equally able to skillfully perform other concurrent tasks. One may even improve performance on disregarded parts of complex tasks, which were learned implicitly. In the present study we investigated the role of sleep in the off-line consolidation of procedural skills when attention is diverted from the procedural task because of interference from a concurrent task. METHODOLOGY/PRINCIPAL FINDINGS: We used a dual-task paradigm containing (i procedural serial reaction time task (SRTT, which was labeled as subordinate and unimportant and (ii declarative word-pair association task (WPAT, performed concomitantly. The WPAT served as a masked distractor to SRTT and was strongly reinforced by the instructions. One experimental and three control groups were tested. The experimental group was re-tested after two nights of sleep (sleep group, SG. The first control group had sleep deprivation on the first post-learning night (nighttime-awake group, NA, the second control group was tested in the morning and then re-tested after 12-hours (daytime-awake group, DA; the third one had the same assignments as DA but with a subsequent, instead of a concomitant, WPAT (daytime-awake-subsequent-WPAT group, DAs. We found SRTT performance gains in SG but not in NA and DA groups. Furthermore, SG reached similar learning gains in SRTT as the DAs group, which gained in SRTT performance because of post-training interference from the declarative task. CONCLUSIONS/SIGNIFICANCE: The results demonstrate that sleep allows off-line consolidation, which is resistant to deteriorating effects of a reinforced distractor on the implicit procedural learning and allowing for gains which are consistent with those produced when inhibited
Working memory (WM) is fundamental to many aspects of human life, including learning, speech and text comprehension, prospection and future planning, and explicit "system 2" forms of reasoning, as well as overlapping...
Geraci, Lisa; Hughes, Matthew L; Miller, Tyler M; De Forrest, Ross L
Negative aging stereotypes can lead older adults to perform poorly on memory tests. Yet, memory performance can be improved if older adults have a single successful experience on a cognitive test prior to participating in a memory experiment (Geraci & Miller, 2013, Psychology and Aging, 28, 340-345). The current study examined the effects of different types of prior task experience on subsequent memory performance. Before participating in a verbal free recall experiment, older adults in Experiment 1 successfully completed either a verbal or a visual cognitive task or no task. In Experiment 2, they successfully completed either a motor task or no task before participating in the free recall experiment. Results from Experiment 1 showed that relative to control (no prior task), participants who had prior success, either on a verbal or a visual task, had better subsequent recall performance. Experiment 2 showed that prior success on a motor task, however, did not lead to a later memory advantage relative to control. These findings demonstrate that older adults' memory can be improved by a successful prior task experience so long as that experience is in a cognitive domain.
Van Hedger, Stephen C; Heald, Shannon L M; Nusbaum, Howard C
Most individuals have reliable long-term memories for the pitch of familiar music recordings. This pitch memory (1) appears to be normally distributed in the population, (2) does not depend on explicit musical training, and (3) only seems to be weakly related to differences in listening frequency estimates. The present experiment was designed to assess whether individual differences in auditory working memory could explain variance in long-term pitch memory for music recordings. In Experiment 1, participants first completed a musical note adjustment task that has been previously used to assess working