Processing speed and visuospatial executive function predict visual working memory ability in older adults.

PubMed

Brown, Louise A; Brockmole, James R; Gow, Alan J; Deary, Ian J

2012-01-01

BACKGROUND/STUDY CONTEXT: Visual working memory (VWM) has been shown to be particularly age sensitive. Determining which measures share variance with this cognitive ability in older adults may help to elucidate the key factors underlying the effects of aging. Predictors of VWM (measured by a modified Visual Patterns Test) were investigated in a subsample (N = 44, mean age = 73) of older adults from the Lothian Birth Cohort 1936 (LBC1936; Deary et al., 2007 , BMC Geriatrics, 7, 28). Childhood intelligence (Moray House Test) and contemporaneous measures of processing speed (four-choice reaction time), executive function (verbal fluency; block design), and spatial working memory (backward spatial span), were assessed as potential predictors. All contemporaneous measures except verbal fluency were significantly associated with VWM, and processing speed had the largest effect size (r = -.53, p < .001). In linear regression analysis, even after adjusting for childhood intelligence, processing speed and the executive measure associated with visuospatial organization accounted for 35% of the variance in VWM. Processing speed may affect VWM performance in older adults via speed of encoding and/or rate of rehearsal, while executive resources specifically associated with visuospatial material are also important.

Individual differences and predictors of forgetting in old age: the role of processing speed and working memory.

PubMed

Zimprich, Daniel; Kurtz, Tanja

2013-01-01

The goal of the present study was to examine whether individual differences in basic cognitive abilities, processing speed, and working memory, are reliable predictors of individual differences in forgetting rates in old age. The sample for the present study comprised 364 participants aged between 65 and 80 years from the Zurich Longitudinal Study on Cognitive Aging. The impact of basic cognitive abilities on forgetting was analyzed by modeling working memory and processing speed as predictors of the amount of forgetting of 27 words, which had been learned across five trials. Forgetting was measured over a 30-minute interval by using parceling and a latent change model, in which the latent difference between recall performance after five learning trials and a delayed recall was modeled. Results implied reliable individual differences in forgetting. These individual differences in forgetting were strongly related to processing speed and working memory. Moreover, an age-related effect, which was significantly stronger for forgetting than for learning, emerged even after controlling effects of processing speed and working memory.

Dietary self-control is related to the speed with which health and taste attributes are processed

PubMed Central

Sullivan, Nicolette; Hutcherson, Cendri; Harris, Alison; Rangel, Antonio

2015-01-01

We propose that self-control failures, and variation across individuals in self-control abilities, are partly due to differences in the speed with which the decision-making circuitry processes basic attributes like taste, versus more abstract attributes such as health. We test these hypotheses by combining a dietary choice task with a novel form of mouse tracking that allows us to pinpoint when different attributes are being integrated into the choice process with millisecond temporal resolution. We find that, on average, taste attributes are processed about 195 ms earlier than health attributes during the choice process. We also find that 13 - 39% of observed individual differences in self-control ability can be explained by differences in the relative speed with which taste and health attributes are processed. PMID:25515527

Dietary self-control is related to the speed with which attributes of healthfulness and tastiness are processed.

PubMed

Sullivan, Nicolette; Hutcherson, Cendri; Harris, Alison; Rangel, Antonio

2015-02-01

We propose that self-control failures, and variation across individuals in self-control abilities, are partly due to differences in the speed with which the decision-making circuitry processes basic attributes, such as tastiness, versus more abstract attributes, such as healthfulness. We tested these hypotheses by combining a dietary-choice task with a novel form of mouse tracking that allowed us to pinpoint when different attributes were being integrated into the choice process with temporal resolution at the millisecond level. We found that, on average, tastiness was processed about 195 ms earlier than healthfulness during the choice process. We also found that 13% to 39% of observed individual differences in self-control ability could be explained by differences in the relative speed with which tastiness and healthfulness were processed. © The Author(s) 2014.

Topography of Slow Sigma Power during Sleep is Associated with Processing Speed in Preschool Children.

PubMed

Doucette, Margaret R; Kurth, Salome; Chevalier, Nicolas; Munakata, Yuko; LeBourgeois, Monique K

2015-11-04

Cognitive development is influenced by maturational changes in processing speed, a construct reflecting the rapidity of executing cognitive operations. Although cognitive ability and processing speed are linked to spindles and sigma power in the sleep electroencephalogram (EEG), little is known about such associations in early childhood, a time of major neuronal refinement. We calculated EEG power for slow (10-13 Hz) and fast (13.25-17 Hz) sigma power from all-night high-density electroencephalography (EEG) in a cross-sectional sample of healthy preschool children (n = 10, 4.3 ± 1.0 years). Processing speed was assessed as simple reaction time. On average, reaction time was 1409 ± 251 ms; slow sigma power was 4.0 ± 1.5 μV²; and fast sigma power was 0.9 ± 0.2 μV². Both slow and fast sigma power predominated over central areas. Only slow sigma power was correlated with processing speed in a large parietal electrode cluster (p < 0.05, r ranging from -0.6 to -0.8), such that greater power predicted faster reaction time. Our findings indicate regional correlates between sigma power and processing speed that are specific to early childhood and provide novel insights into the neurobiological features of the EEG that may underlie developing cognitive abilities.

Cognitive Performance across the Life Course of Bolivian Forager-Farmers with Limited Schooling

ERIC Educational Resources Information Center

Gurven, Michael; Fuerstenberg, Eric; Trumble, Benjamin; Stieglitz, Jonathan; Beheim, Bret; Davis, Helen; Kaplan, Hillard

2017-01-01

Cognitive performance is characterized by at least two distinct life course trajectories. Many cognitive abilities (e.g., "effortful processing" abilities, including fluid reasoning and processing speed) improve throughout early adolescence and start declining in early adulthood, whereas other abilities (e.g., "crystallized"…

Individual differences in perceiving and recognizing faces-One element of social cognition.

PubMed

Wilhelm, Oliver; Herzmann, Grit; Kunina, Olga; Danthiir, Vanessa; Schacht, Annekathrin; Sommer, Werner

2010-09-01

Recognizing faces swiftly and accurately is of paramount importance to humans as a social species. Individual differences in the ability to perform these tasks may therefore reflect important aspects of social or emotional intelligence. Although functional models of face cognition based on group and single case studies postulate multiple component processes, little is known about the ability structure underlying individual differences in face cognition. In 2 large individual differences experiments (N = 151 and N = 209), a broad variety of face-cognition tasks were tested and the component abilities of face cognition-face perception, face memory, and the speed of face cognition-were identified and then replicated. Experiment 2 also showed that the 3 face-cognition abilities are clearly distinct from immediate and delayed memory, mental speed, general cognitive ability, and object cognition. These results converge with functional and neuroanatomical models of face cognition by demonstrating the difference between face perception and face memory. The results also underline the importance of distinguishing between speed and accuracy of face cognition. Together our results provide a first step toward establishing face-processing abilities as an independent ability reflecting elements of social intelligence. (PsycINFO Database Record (c) 2010 APA, all rights reserved).

Developmental Steps in Metaphorical Language Abilities: The Influence of Age, Gender, Cognitive Flexibility, Information Processing Speed, and Analogical Reasoning.

PubMed

Willinger, Ulrike; Deckert, Matthias; Schmöger, Michaela; Schaunig-Busch, Ines; Formann, Anton K; Auff, Eduard

2017-12-01

Metaphor is a specific type of figurative language that is used in various important fields such as in the work with children in clinical or teaching contexts. The aim of the study was to investigate the developmental course, developmental steps, and possible cognitive predictors regarding metaphor processing in childhood and early adolescence. One hundred sixty-four typically developing children (7-year-olds, 9-year-olds) and early adolescents (11-year-olds) were tested for metaphor identification, comprehension, comprehension quality, and preference by the Metaphoric Triads Task as well as for analogical reasoning, information processing speed, cognitive flexibility under time pressure, and cognitive flexibility without time pressure. Metaphor identification and comprehension consecutively increased with age. Eleven-year-olds showed significantly higher metaphor comprehension quality and preference scores than seven- and nine-year-olds, whilst these younger age groups did not differ. Age, cognitive flexibility under time pressure, information processing speed, analogical reasoning, and cognitive flexibility without time pressure significantly predicted metaphor comprehension. Metaphorical language ability shows an ongoing development and seemingly changes qualitatively at the beginning of early adolescence. These results can possibly be explained by a greater synaptic reorganization in early adolescents. Furthermore, cognitive flexibility under time pressure and information processing speed possibly facilitate the ability to adapt metaphor processing strategies in a flexible, quick, and appropriate way.

Pathways From Toddler Information Processing to Adolescent Lexical Proficiency.

PubMed

Rose, Susan A; Feldman, Judith F; Jankowski, Jeffery J

2015-01-01

This study examined the relation of 3-year core information-processing abilities to lexical growth and development. The core abilities covered four domains-memory, representational competence (cross-modal transfer), processing speed, and attention. Lexical proficiency was assessed at 3 and 13 years with the Peabody Picture Vocabulary Test (PPVT) and verbal fluency. The sample (N = 128) consisted of 43 preterms (< 1750 g) and 85 full-terms. Structural equation modeling indicated concurrent relations of toddler information processing and language proficiency and, independent of stability in language, direct predictive links between (a) 3-year cross-modal ability and 13-year PPVT and (b) 3-year processing speed and both 13-year measures, PPVT and verbal fluency. Thus, toddler information processing was related to growth in lexical proficiency from 3 to 13 years. © 2015 The Authors. Child Development © 2015 Society for Research in Child Development, Inc.

Topography of Slow Sigma Power during Sleep is Associated with Processing Speed in Preschool Children

PubMed Central

Doucette, Margaret R.; Kurth, Salome; Chevalier, Nicolas; Munakata, Yuko; LeBourgeois, Monique K.

2015-01-01

Cognitive development is influenced by maturational changes in processing speed, a construct reflecting the rapidity of executing cognitive operations. Although cognitive ability and processing speed are linked to spindles and sigma power in the sleep electroencephalogram (EEG), little is known about such associations in early childhood, a time of major neuronal refinement. We calculated EEG power for slow (10–13 Hz) and fast (13.25–17 Hz) sigma power from all-night high-density electroencephalography (EEG) in a cross-sectional sample of healthy preschool children (n = 10, 4.3 ± 1.0 years). Processing speed was assessed as simple reaction time. On average, reaction time was 1409 ± 251 ms; slow sigma power was 4.0 ± 1.5 μV2; and fast sigma power was 0.9 ± 0.2 μV2. Both slow and fast sigma power predominated over central areas. Only slow sigma power was correlated with processing speed in a large parietal electrode cluster (p < 0.05, r ranging from −0.6 to −0.8), such that greater power predicted faster reaction time. Our findings indicate regional correlates between sigma power and processing speed that are specific to early childhood and provide novel insights into the neurobiological features of the EEG that may underlie developing cognitive abilities. PMID:26556377

The Genetic and Environmental Etiologies of the Relations between Cognitive Skills and Components of Reading Ability

PubMed Central

Christopher, Micaela E.; Keenan, Janice M.; Hulslander, Jacqueline; DeFries, John C.; Miyake, Akira; Wadsworth, Sally J.; Willcutt, Erik; Pennington, Bruce; Olson, Richard K.

2016-01-01

While previous research has shown cognitive skills to be important predictors of reading ability in children, the respective roles for genetic and environmental influences on these relations is an open question. The present study explored the genetic and environmental etiologies underlying the relations between selected executive functions and cognitive abilities (working memory, inhibition, processing speed, and naming speed) with three components of reading ability (word reading, reading comprehension, and listening comprehension). Twin pairs drawn from the Colorado Front Range (n = 676; 224 monozygotic pairs; 452 dizygotic pairs) between the ages of eight and 16 (M = 11.11) were assessed on multiple measures of each cognitive and reading-related skill. Each cognitive and reading-related skill was modeled as a latent variable, and behavioral genetic analyses estimated the portions of phenotypic variance on each latent variable due to genetic, shared environmental, and nonshared environmental influences. The covariance between the cognitive skills and reading-related skills was driven primarily by genetic influences. The cognitive skills also shared large amounts of genetic variance, as did the reading-related skills. The common cognitive genetic variance was highly correlated with the common reading genetic variance, suggesting that genetic influences involved in general cognitive processing are also important for reading ability. Skill-specific genetic variance in working memory and processing speed also predicted components of reading ability. Taken together, the present study supports a genetic association between children’s cognitive ability and reading ability. PMID:26974208

Age-related decline in cognitive control: the role of fluid intelligence and processing speed

PubMed Central

2014-01-01

Background Research on cognitive control suggests an age-related decline in proactive control abilities whereas reactive control seems to remain intact. However, the reason of the differential age effect on cognitive control efficiency is still unclear. This study investigated the potential influence of fluid intelligence and processing speed on the selective age-related decline in proactive control. Eighty young and 80 healthy older adults were included in this study. The participants were submitted to a working memory recognition paradigm, assessing proactive and reactive cognitive control by manipulating the interference level across items. Results Repeated measures ANOVAs and hierarchical linear regressions indicated that the ability to appropriately use cognitive control processes during aging seems to be at least partially affected by the amount of available cognitive resources (assessed by fluid intelligence and processing speed abilities). Conclusions This study highlights the potential role of cognitive resources on the selective age-related decline in proactive control, suggesting the importance of a more exhaustive approach considering the confounding variables during cognitive control assessment. PMID:24401034

Can Training Enhance Face Cognition Abilities in Middle-Aged Adults?

PubMed Central

Dolzycka, Dominika; Herzmann, Grit; Sommer, Werner; Wilhelm, Oliver

2014-01-01

Face cognition is a crucial skill for social interaction and shows large individual differences in healthy adults, suggesting a possibility for improvement in some. We developed and tested specific training procedures for the accuracy of face memory and the speed of face cognition. Two groups each of 20 healthy middle-aged trainees practiced for 29 daily sessions of 15 minutes duration with different computerized home-based training procedures. In addition, 20 matched and 59 non-matched controls were included. Face cognition speed training enhanced performance during the training and transferred to the latent factor level as measured in a pre-post comparison. Persistence of the training effect was evidenced at the manifest level after three months. However, the training procedure influenced the speed of processing object stimuli to the same extent as face stimuli and therefore seems to have affected a more general ability of processing complex visual stimuli and not only faces. No effects of training on the accuracy of face memory were found. This study demonstrates that face-specific abilities may be hard to improve but also shows the plasticity of the speed of processing complex visual stimuli – for the first time in middle-aged, normal adults. PMID:24632743

Pathways from Toddler Information Processing to Adolescent Lexical Proficiency

ERIC Educational Resources Information Center

Rose, Susan A.; Feldman, Judith F.; Jankowski, Jeffery J.

2015-01-01

This study examined the relation of 3-year core information-processing abilities to lexical growth and development. The core abilities covered four domains--memory, representational competence (cross-modal transfer), processing speed, and attention. Lexical proficiency was assessed at 3 and 13 years with the Peabody Picture Vocabulary Test (PPVT)…

Visual processing speed in old age.

PubMed

Habekost, Thomas; Vogel, Asmus; Rostrup, Egill; Bundesen, Claus; Kyllingsbaek, Søren; Garde, Ellen; Ryberg, Charlotte; Waldemar, Gunhild

2013-04-01

Mental speed is a common concept in theories of cognitive aging, but it is difficult to get measures of the speed of a particular psychological process that are not confounded by the speed of other processes. We used Bundesen's (1990) Theory of Visual Attention (TVA) to obtain specific estimates of processing speed in the visual system controlled for the influence of response latency and individual variations of the perception threshold. A total of 33 non-demented old people (69-87 years) were tested for the ability to recognize briefly presented letters. Performance was analyzed by the TVA model. Visual processing speed decreased approximately linearly with age and was on average halved from 70 to 85 years. Less dramatic aging effects were found for the perception threshold and the visual apprehension span. In the visual domain, cognitive aging seems to be most clearly related to reductions in processing speed. © 2012 The Authors. Scandinavian Journal of Psychology © 2012 The Scandinavian Psychological Associations.

The role of auditory and cognitive factors in understanding speech in noise by normal-hearing older listeners

PubMed Central

Schoof, Tim; Rosen, Stuart

2014-01-01

Normal-hearing older adults often experience increased difficulties understanding speech in noise. In addition, they benefit less from amplitude fluctuations in the masker. These difficulties may be attributed to an age-related auditory temporal processing deficit. However, a decline in cognitive processing likely also plays an important role. This study examined the relative contribution of declines in both auditory and cognitive processing to the speech in noise performance in older adults. Participants included older (60–72 years) and younger (19–29 years) adults with normal hearing. Speech reception thresholds (SRTs) were measured for sentences in steady-state speech-shaped noise (SS), 10-Hz sinusoidally amplitude-modulated speech-shaped noise (AM), and two-talker babble. In addition, auditory temporal processing abilities were assessed by measuring thresholds for gap, amplitude-modulation, and frequency-modulation detection. Measures of processing speed, attention, working memory, Text Reception Threshold (a visual analog of the SRT), and reading ability were also obtained. Of primary interest was the extent to which the various measures correlate with listeners' abilities to perceive speech in noise. SRTs were significantly worse for older adults in the presence of two-talker babble but not SS and AM noise. In addition, older adults showed some cognitive processing declines (working memory and processing speed) although no declines in auditory temporal processing. However, working memory and processing speed did not correlate significantly with SRTs in babble. Despite declines in cognitive processing, normal-hearing older adults do not necessarily have problems understanding speech in noise as SRTs in SS and AM noise did not differ significantly between the two groups. Moreover, while older adults had higher SRTs in two-talker babble, this could not be explained by age-related cognitive declines in working memory or processing speed. PMID:25429266

Placing Inspection Time, Reaction Time, and Perceptual Speed in the Broader Context of Cognitive Ability: The VPR Model in the Lothian Birth Cohort 1936

ERIC Educational Resources Information Center

Johnson, Wendy; Deary, Ian J.

2011-01-01

The idea that information processing speed is related to cognitive ability has a long history. Much evidence has been amassed in its support, with respect to both individual differences in general intelligence and developmental trajectories. Two so-called elementary cognitive tasks, reaction time and inspection time, have been used to compile this…

Modeling the Covariance Structure of Complex Datasets Using Cognitive Models: An Application to Individual Differences and the Heritability of Cognitive Ability.

PubMed

Evans, Nathan J; Steyvers, Mark; Brown, Scott D

2018-06-05

Understanding individual differences in cognitive performance is an important part of understanding how variations in underlying cognitive processes can result in variations in task performance. However, the exploration of individual differences in the components of the decision process-such as cognitive processing speed, response caution, and motor execution speed-in previous research has been limited. Here, we assess the heritability of the components of the decision process, with heritability having been a common aspect of individual differences research within other areas of cognition. Importantly, a limitation of previous work on cognitive heritability is the underlying assumption that variability in response times solely reflects variability in the speed of cognitive processing. This assumption has been problematic in other domains, due to the confounding effects of caution and motor execution speed on observed response times. We extend a cognitive model of decision-making to account for relatedness structure in a twin study paradigm. This approach can separately quantify different contributions to the heritability of response time. Using data from the Human Connectome Project, we find strong evidence for the heritability of response caution, and more ambiguous evidence for the heritability of cognitive processing speed and motor execution speed. Our study suggests that the assumption made in previous studies-that the heritability of cognitive ability is based on cognitive processing speed-may be incorrect. More generally, our methodology provides a useful avenue for future research in complex data that aims to analyze cognitive traits across different sources of related data, whether the relation is between people, tasks, experimental phases, or methods of measurement. © 2018 Cognitive Science Society, Inc.

Revisiting the Relations between the WJ-IV Measures of Cattell-Horn-Carroll (CHC) Cognitive Abilities and Reading Achievement during the School-Age Years

ERIC Educational Resources Information Center

Cormier, Damien C.; McGrew, Kevin S.; Bulut, Okan; Funamoto, Allyson

2017-01-01

This study examined associations between broad cognitive abilities (Fluid Reasoning [Gf], Short-Term Working Memory [Gwm], Long-Term Storage and Retrieval [Glr], Processing Speed [Gs], Comprehension-Knowledge [Gc], Visual Processing [Gv], and Auditory Processing [Ga]) and reading achievement (Basic Reading Skills, Reading Rate, Reading Fluency,…

Selective Attention with Separable Stimuli Using a Speeded Task.

ERIC Educational Resources Information Center

Kolbet, Lori L.; Garvey, Jackie

The ability to allocate attentional resources to relevant aspects of a stimulus event is a critical skill needed for efficient information processing. Evidence suggests that this ability to focus on relevant information without interference is dependent on the nature of the stimulus structure of the information to be processed. To test the…

A watershed model of individual differences in fluid intelligence.

PubMed

Kievit, Rogier A; Davis, Simon W; Griffiths, John; Correia, Marta M; Cam-Can; Henson, Richard N

2016-10-01

Fluid intelligence is a crucial cognitive ability that predicts key life outcomes across the lifespan. Strong empirical links exist between fluid intelligence and processing speed on the one hand, and white matter integrity and processing speed on the other. We propose a watershed model that integrates these three explanatory levels in a principled manner in a single statistical model, with processing speed and white matter figuring as intermediate endophenotypes. We fit this model in a large (N=555) adult lifespan cohort from the Cambridge Centre for Ageing and Neuroscience (Cam-CAN) using multiple measures of processing speed, white matter health and fluid intelligence. The model fit the data well, outperforming competing models and providing evidence for a many-to-one mapping between white matter integrity, processing speed and fluid intelligence. The model can be naturally extended to integrate other cognitive domains, endophenotypes and genotypes. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Comment on Goldhammer's "Measuring Ability, Speed, or Both"

ERIC Educational Resources Information Center

Davison, Mark L.

2016-01-01

The answer to the question, "Ability, speed, or both?" may be "both at once" if speed is simply a manifestation of ability. If differences in speed are manifestations of differences in ability, then both speed and ability may reflect a single dimension best characterized by a single score. While measurement of speed has proven…

Inhibition and Updating, but Not Switching, Predict Developmental Dyslexia and Individual Variation in Reading Ability

PubMed Central

Doyle, Caoilainn; Smeaton, Alan F.; Roche, Richard A. P.; Boran, Lorraine

2018-01-01

To elucidate the core executive function profile (strengths and weaknesses in inhibition, updating, and switching) associated with dyslexia, this study explored executive function in 27 children with dyslexia and 29 age matched controls using sensitive z-mean measures of each ability and controlled for individual differences in processing speed. This study found that developmental dyslexia is associated with inhibition and updating, but not switching impairments, at the error z-mean composite level, whilst controlling for processing speed. Inhibition and updating (but not switching) error composites predicted both dyslexia likelihood and reading ability across the full range of variation from typical to atypical. The predictive relationships were such that those with poorer performance on inhibition and updating measures were significantly more likely to have a diagnosis of developmental dyslexia and also demonstrate poorer reading ability. These findings suggest that inhibition and updating abilities are associated with developmental dyslexia and predict reading ability. Future studies should explore executive function training as an intervention for children with dyslexia as core executive functions appear to be modifiable with training and may transfer to improved reading ability. PMID:29892245

Effects of lorazepam on visual perceptual abilities.

PubMed

Pompéia, S; Pradella-Hallinan, M; Manzano, G M; Bueno, O F A

2008-04-01

To evaluate the effects of an acute dose of the benzodiazepine (BZ) lorazepam in young healthy volunteers on five distinguishable visual perception abilities determined by previous factor-analytic studies. This was a double-blind, cross-over design study of acute oral doses of lorazepam (2 mg) and placebo in young healthy volunteers. We focused on a set of paper-and-pencil tests of visual perceptual abilities that load on five correlated but distinguishable factors (Spatial Visualization, Spatial Relations, Perceptual Speed, Closure Speed, and Closure Flexibility). Some other tests (DSST, immediate and delayed recall of prose; measures of subjective mood alterations) were used to control for the classic BZ-induced effects. Lorazepam impaired performance in the DSST and delayed recall of prose, increased subjective sedation and impaired tasks of all abilities except Spatial Visualization and Closure Speed. Only impairment in Perceptual Speed (Identical Pictures task) and delayed recall of prose were not explained by sedation. Acute administration of lorazepam, in a dose that impaired episodic memory, selectively affected different visual perceptual abilities before and after controlling for sedation. Central executive demands and sedation did not account for results, so impairment in the Identical Pictures task may be attributed to lorazepam's visual processing alterations. 2008 John Wiley & Sons, Ltd.

Automation and Mankind

DTIC Science & Technology

1960-08-07

limited by the cap- abilities of the human organism in the matter of control of its processes. In our time, the speeds of technological processes are...in many cases limited by conditions of control. The speed of human reaction is limited and therefore, at pre- sent, only processes of a relatively...forwiard, It can e foreseer thast automIation will comp~letely free Mans -Pn work unler conlitions’ of high texpemratures pressures,, anid nollutA-: or

Working Memory in Children With Neurocognitive Effects From Sickle Cell Disease: Contributions of the Central Executive and Processing Speed

PubMed Central

Smith, Kelsey E.; Schatz, Jeffrey

2017-01-01

Children with sickle cell disease (SCD) are at risk for working memory deficits due to multiple disease processes. We assessed working memory abilities and related functions in 32 school-age children with SCD and 85 matched comparison children using Baddeley’s working memory model as a framework. Children with SCD performed worse than controls for working memory, central executive function, and processing/rehearsal speed. Central executive function was found to mediate the relationship between SCD status and working memory, but processing speed did not. Cognitive remediation strategies that focus on central executive processes may be important for remediating working memory deficits in SCD. PMID:27759435

The Effects of Wechsler Intelligence Scale for Children-Fourth Edition Cognitive Abilities on Math Achievement

ERIC Educational Resources Information Center

Parkin, Jason R.; Beaujean, A. Alexander

2012-01-01

This study used structural equation modeling to examine the effect of Stratum III (i.e., general intelligence) and Stratum II (i.e., Comprehension-Knowledge, Fluid Reasoning, Short-Term Memory, Processing Speed, and Visual Processing) factors of the Cattell-Horn-Carroll (CHC) cognitive abilities, as operationalized by the Wechsler Intelligence…

Cognitive psychology meets psychometric theory: on the relation between process models for decision making and latent variable models for individual differences.

PubMed

van der Maas, Han L J; Molenaar, Dylan; Maris, Gunter; Kievit, Rogier A; Borsboom, Denny

2011-04-01

This article analyzes latent variable models from a cognitive psychology perspective. We start by discussing work by Tuerlinckx and De Boeck (2005), who proved that a diffusion model for 2-choice response processes entails a 2-parameter logistic item response theory (IRT) model for individual differences in the response data. Following this line of reasoning, we discuss the appropriateness of IRT for measuring abilities and bipolar traits, such as pro versus contra attitudes. Surprisingly, if a diffusion model underlies the response processes, IRT models are appropriate for bipolar traits but not for ability tests. A reconsideration of the concept of ability that is appropriate for such situations leads to a new item response model for accuracy and speed based on the idea that ability has a natural zero point. The model implies fundamentally new ways to think about guessing, response speed, and person fit in IRT. We discuss the relation between this model and existing models as well as implications for psychology and psychometrics. 2011 APA, all rights reserved

Is rapid automatized naming related to reading and mathematics for the same reason(s)? A follow-up study from kindergarten to Grade 1.

PubMed

Georgiou, George K; Tziraki, Niki; Manolitsis, George; Fella, Argyro

2013-07-01

We examined (a) what rapid automatized naming (RAN) components (articulation time and/or pause time) predict reading and mathematics ability and (b) what processing skills involved in RAN (speed of processing, response inhibition, working memory, and/or phonological awareness) may explain its relationship with reading and mathematics. A sample of 72 children were followed from the beginning of kindergarten until the end of Grade 1 and were assessed on measures of RAN, general cognitive ability, speed of processing, attention, working memory, phonological awareness, reading, and mathematics. The results indicated that pause time was the critical component in both the RAN-reading and RAN-mathematics relationships and that it shared most of its predictive variance in reading and mathematics with speed of processing and working memory. Our findings further suggested that, unlike the relationship between RAN and reading fluency in Grade 1, there is nothing in the RAN task that is uniquely related to math. Copyright © 2013 Elsevier Inc. All rights reserved.

Faster on Easy Items, More Accurate on Difficult Ones: Cognitive Ability and Performance on a Task of Varying Difficulty

ERIC Educational Resources Information Center

Dodonova, Yulia A.; Dodonov, Yury S.

2013-01-01

Using more complex items than those commonly employed within the information-processing approach, but still easier than those used in intelligence tests, this study analyzed how the association between processing speed and accuracy level changes as the difficulty of the items increases. The study involved measuring cognitive ability using Raven's…

Visual temporal processing in dyslexia and the magnocellular deficit theory: the need for speed?

PubMed

McLean, Gregor M T; Stuart, Geoffrey W; Coltheart, Veronika; Castles, Anne

2011-12-01

A controversial question in reading research is whether dyslexia is associated with impairments in the magnocellular system and, if so, how these low-level visual impairments might affect reading acquisition. This study used a novel chromatic flicker perception task to specifically explore temporal aspects of magnocellular functioning in 40 children with dyslexia and 42 age-matched controls (aged 7-11). The relationship between magnocellular temporal resolution and higher-level aspects of visual temporal processing including inspection time, single and dual-target (attentional blink) RSVP performance, go/no-go reaction time, and rapid naming was also assessed. The Dyslexia group exhibited significant deficits in magnocellular temporal resolution compared with controls, but the two groups did not differ in parvocellular temporal resolution. Despite the significant group differences, associations between magnocellular temporal resolution and reading ability were relatively weak, and links between low-level temporal resolution and reading ability did not appear specific to the magnocellular system. Factor analyses revealed that a collective Perceptual Speed factor, involving both low-level and higher-level visual temporal processing measures, accounted for unique variance in reading ability independently of phonological processing, rapid naming, and general ability.

Neonatal Brain Pathology Predicts Adverse Attention and Processing Speed Outcomes in Very Preterm and/or Very Low Birth Weight Children

PubMed Central

Murray, Andrea L; Scratch, Shannon E; Thompson, Deanne K; Inder, Terrie E; Doyle, Lex W; Anderson, Jacqueline F. I.; Anderson, Peter J

2014-01-01

Objective This study aimed to examine attention and processing speed outcomes in very preterm (VPT; <32 weeks' gestational age) or very low birth weight (VLBW; <1500 g) children, and to assess the ability of brain abnormalities measured by neonatal magnetic resonance imaging (MRI) to predict outcome in these domains. Methods A cohort of 198 children born <30 weeks' gestational age and/or <1250 g and 70 term controls were examined. Neonatal MRI scans at term equivalent age were quantitatively assessed for white matter, cortical gray matter, deep gray matter, and cerebellar abnormalities. Attention and processing speed were assessed at 7 years using standardized neuropsychological tests. Group differences were tested in attention and processing speed, and the relationships between these cognitive domains and brain abnormalities at birth were investigated. Results At 7 years of age, the VPT/VLBW group performed significantly poorer than term controls on all attention and processing speed outcomes. Associations between adverse attention and processing speed performances at 7 years and higher neonatal brain abnormality scores were found; in particular, white matter and deep gray matter abnormalities were reasonable predictors of long-term cognitive outcomes. Conclusion Attention and processing speed are significant areas of concern in VPT/VLBW children. This is the first study to show that adverse attention and processing speed outcomes at 7 years are associated with neonatal brain pathology. PMID:24708047

Verbal learning in schizopsychotic outpatients and healthy volunteers as a function of cognitive performance levels.

PubMed

Karilampi, Ulla; Helldin, Lars; Hjärthag, Fredrik; Norlander, Torsten; Archer, Trevor

2007-02-01

The aim was to analyze and compare neurocognitive test profiles related to different levels of verbal learning performance among schizopsychotic patients and healthy volunteers. A single-center patient cohort of 196 participants was compared with an equal-sized volunteer group to form three cognitive subgroups based on the shared verbal learning performance. 43.9% of the patients had normal learning ability. Despite this, all patients underperformed the volunteers on all subtests with the exception of working memory, and, for those with high learning ability, even verbal facility. All patients also presented equally poor visuomotor processing speed/efficacy. A global neurocognitive retardation of speed-related processing in schizophrenia is suggested.

Automatic detection of health changes using statistical process control techniques on measured transfer times of elderly.

PubMed

Baldewijns, Greet; Luca, Stijn; Nagels, William; Vanrumste, Bart; Croonenborghs, Tom

2015-01-01

It has been shown that gait speed and transfer times are good measures of functional ability in elderly. However, data currently acquired by systems that measure either gait speed or transfer times in the homes of elderly people require manual reviewing by healthcare workers. This reviewing process is time-consuming. To alleviate this burden, this paper proposes the use of statistical process control methods to automatically detect both positive and negative changes in transfer times. Three SPC techniques: tabular CUSUM, standardized CUSUM and EWMA, known for their ability to detect small shifts in the data, are evaluated on simulated transfer times. This analysis shows that EWMA is the best-suited method with a detection accuracy of 82% and an average detection time of 9.64 days.

Neuropsychological Profiles on the WAIS-IV of Adults With ADHD.

PubMed

Theiling, Johanna; Petermann, Franz

2016-11-01

The aim of the study was to investigate the pattern of neuropsychological profiles on the Wechsler Adult Intelligence Scale-IV (WAIS-IV) for adults With ADHD relative to randomly matched controls and to assess overall intellectual ability discrepancies of the Full Scale Intelligence Quotient (FSIQ) and the General Ability Index (GAI). In all, 116 adults With ADHD and 116 controls between 16 and 71 years were assessed. Relative to controls, adults With ADHD show significant decrements in subtests with working memory and processing speed demands with moderate to large effect sizes and a higher GAI in comparison with the FSIQ. This suggests first that deficits identified with previous WAIS versions are robust in adults With ADHD and remain deficient when assessed with the WAIS-IV; second that the WAIS-IV reliably differentiates between patients and controls; and third that a reduction of the FSIQ is most likely due to a decrement in working memory and processing speed abilities. The findings have essential implications for the diagnostic process. © The Author(s) 2014.

The effects of an exercise program on several abilities associated with driving performance in older adults.

PubMed

Marmeleira, José F; Godinho, Mário B; Fernandes, Orlando M

2009-01-01

The purpose of this study was to investigate the effects of participation in an exercise program on several abilities associated with driving performance in older adults. Thirty-two subjects were randomly assigned to either an exercise group (60-81 years, n=16) or a control group (60-82 years, n=16). The exercise program was planned to stress perceptive, cognitive, and physical abilities. It lasted 12 weeks with a periodicity of three sessions of 60 min per week. Assessments were conducted before and after the intervention on behavioral speed (in single- and dual-task conditions), visual attention, psychomotor performance, speed perception (time-to-contact), and executive functioning. Significant positive effects were found at 12-week follow-up resulting from participation in the exercise program. Behavioral speed improvements were found in reaction time, movement time, and response time (both in single- and dual-task conditions); visual attention improvements took place in speed processing and divided attention; psychomotor performance improvements occurred in lower limb mobility. These results showed that exercise is capable of enhancing several abilities relevant for driving performance and safety in older adults and, therefore, should be promoted.

Hidden Markov Item Response Theory Models for Responses and Response Times.

PubMed

Molenaar, Dylan; Oberski, Daniel; Vermunt, Jeroen; De Boeck, Paul

2016-01-01

Current approaches to model responses and response times to psychometric tests solely focus on between-subject differences in speed and ability. Within subjects, speed and ability are assumed to be constants. Violations of this assumption are generally absorbed in the residual of the model. As a result, within-subject departures from the between-subject speed and ability level remain undetected. These departures may be of interest to the researcher as they reflect differences in the response processes adopted on the items of a test. In this article, we propose a dynamic approach for responses and response times based on hidden Markov modeling to account for within-subject differences in responses and response times. A simulation study is conducted to demonstrate acceptable parameter recovery and acceptable performance of various fit indices in distinguishing between different models. In addition, both a confirmatory and an exploratory application are presented to demonstrate the practical value of the modeling approach.

Diagnostic efficiency of an ability-focused battery.

PubMed

Miller, Justin B; Fichtenberg, Norman L; Millis, Scott R

2010-05-01

An ability-focused battery (AFB) is a selected group of well-validated neuropsychological measures that assess the conventional range of cognitive domains. This study examined the diagnostic efficiency of an AFB for use in clinical decision making with a mixed sample composed of individuals with neurological brain dysfunction and individuals referred for cognitive assessment without evidence of neurological disorders. Using logistic regression analyses and ROC curve analysis, a five-domain model composed of attention, processing speed, visual-spatial reasoning, language/verbal reasoning, and memory domain scores was fitted that had an AUC of.89 (95% CI =.84-.95). A more parsimonious two-domain model using processing speed and memory was also fitted that had an AUC of.90 (95% confidence interval =.84-.95). A model composed of a global ability score calculated from the mean of the individual domain scores was also fitted with an AUC of.88 (95% CI =.82-.94).

Impaired recognition of happy facial expressions in bipolar disorder.

PubMed

Lawlor-Savage, Linette; Sponheim, Scott R; Goghari, Vina M

2014-08-01

The ability to accurately judge facial expressions is important in social interactions. Individuals with bipolar disorder have been found to be impaired in emotion recognition; however, the specifics of the impairment are unclear. This study investigated whether facial emotion recognition difficulties in bipolar disorder reflect general cognitive, or emotion-specific, impairments. Impairment in the recognition of particular emotions and the role of processing speed in facial emotion recognition were also investigated. Clinically stable bipolar patients (n = 17) and healthy controls (n = 50) judged five facial expressions in two presentation types, time-limited and self-paced. An age recognition condition was used as an experimental control. Bipolar patients' overall facial recognition ability was unimpaired. However, patients' specific ability to judge happy expressions under time constraints was impaired. Findings suggest a deficit in happy emotion recognition impacted by processing speed. Given the limited sample size, further investigation with a larger patient sample is warranted.

NBC Contamination Survivability, Large Item Exteriors

DTIC Science & Technology

1998-04-17

environment. Ability to control temperature , relative humidity (RH), and wind speed is required. The facility must be designed to ensure safe and...2.2 Instrumentation. Measuring Devices Permissible Error of Measurement Air temperature ±0.5°C Relative humidity (RH) ±5 % Wind speed ±0.1 rm/sec Still...process, excluding monitoring, should last no longer than 75 minutes. (3) The item surface temperature is 30’C and exterior wind speed is no greater

Effects of information processing speed on learning, memory, and executive functioning in people living with HIV/AIDS.

PubMed

Fellows, Robert P; Byrd, Desiree A; Morgello, Susan

2014-01-01

It is unclear whether or to what degree literacy, aging, and other neurologic abnormalities relate to cognitive deficits among people living with HIV/AIDS in the combined antiretroviral therapy (CART) era. The primary aim of this study was to simultaneously examine the association of age, HIV-associated motor abnormalities, major depressive disorder, and reading level with information processing speed, learning, memory, and executive functions, and to determine whether processing speed mediated any of the relationships between cognitive and noncognitive variables. Participants were 186 racially and ethnically diverse men and women living with HIV/AIDS who underwent comprehensive neurological, neuropsychological, and medical evaluations. Structural equation modeling was utilized to assess the extent to which information processing speed mediated the relationship between age, motor abnormalities, major depressive disorder, and reading level with other cognitive abilities. Age, motor dysfunction, reading level, and current major depressive disorder were all significantly associated with information processing speed. Information processing speed fully mediated the effects of age on learning, memory, and executive functioning and partially mediated the effect of major depressive disorder on learning and memory. The effect of motor dysfunction on learning and memory was fully mediated by processing speed. These findings provide support for information processing speed as a primary deficit, which may account, at least in part, for many of the other cognitive abnormalities recognized in complex HIV/AIDS populations. The association of age and information processing speed may account for HIV/aging synergies in the generation of CART-era cognitive abnormalities.

Acquisition of Programming Skills

DTIC Science & Technology

1990-04-01

skills (e.g., arithmetic reasoning, work knowledge, information processing speed); and c) passive versus active learning style. Ability measures...concurrent storage and processing an individual was capable of doing), and an active learning style. Implications of the findings for the development of

Fabrication and Characterization of High Strength Al-Cu Alloys Processed Using Laser Beam Melting in Metal Powder Bed

NASA Astrophysics Data System (ADS)

Ahuja, Bhrigu; Karg, Michael; Nagulin, Konstantin Yu.; Schmidt, Michael

The proposed paper illustrates fabrication and characterization of high strength Aluminium Copper alloys processed using Laser Beam Melting process. Al-Cu alloys EN AW-2219 and EN AW-2618 are classified as wrought alloys and 2618 is typically considered difficult to weld. Laser Beam Melting (LBM) process from the family of Additive Manufacturing processes, has the unique ability to form fully dense complex 3D geometries using micro sized metallic powder in a layer by layer fabrication methodology. LBM process can most closely be associated to the conventional laser welding process, but has significant differences in terms of the typical laser intensities and scan speeds used. Due to the use of high intensities and fast scan speeds, the process induces extremely high heating and cooling rates. This property gives it a unique physical attribute and therefore its ability to process high strength Al-Cu alloys needs to be investigated. Experiments conducted during the investigations associate the induced energy density controlled by varying process parameters to the achieved relative densities of the fabricated 3D structures.

Planning Decrements in Healthy Aging: Mediation Effects of Fluid Reasoning and Working Memory Capacity.

PubMed

Köstering, Lena; Leonhart, Rainer; Stahl, Christoph; Weiller, Cornelius; Kaller, Christoph P

2016-03-01

Although age-related differences in planning ability are well known, their cognitive foundations remain a matter of contention. To elucidate the specific processes underlying planning decrements in older age, the relative contributions of fluid reasoning, working memory (WM) capacity, and processing speed to accuracy on the Tower of London (TOL) planning task were investigated. Mediation analyses were used to relate overall and search depth-related TOL accuracy from older (N = 106; 60-89 years) and younger adults (N = 69; 18-54 years) to age and measures of fluid reasoning, WM capacity, and speed. For overall planning, fluid abilities mediated the effects of age, WM capacity, and speed in older adults. By contrast, fluid abilities and WM capacity mediated each other in younger adults. For planning accuracy under low demands on the depth of search, WM capacity was specifically important in older age, whereas younger adults recruited both WM capacity and fluid reasoning. Under high search-depth-demands, fluid abilities underlay the cognitive operations critical for resolving move interdependencies in both age groups. Fluid abilities and WM capacity undergo significant changes from younger to older age in their unique contribution to planning, which might represent a mechanism whereby planning decrements in older age are brought about. © The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Enhanced visual short-term memory in action video game players.

PubMed

Blacker, Kara J; Curby, Kim M

2013-08-01

Visual short-term memory (VSTM) is critical for acquiring visual knowledge and shows marked individual variability. Previous work has illustrated a VSTM advantage among action video game players (Boot et al. Acta Psychologica 129:387-398, 2008). A growing body of literature has suggested that action video game playing can bolster visual cognitive abilities in a domain-general manner, including abilities related to visual attention and the speed of processing, providing some potential bases for this VSTM advantage. In the present study, we investigated the VSTM advantage among video game players and assessed whether enhanced processing speed can account for this advantage. Experiment 1, using simple colored stimuli, revealed that action video game players demonstrate a similar VSTM advantage over nongamers, regardless of whether they are given limited or ample time to encode items into memory. Experiment 2, using complex shapes as the stimuli to increase the processing demands of the task, replicated this VSTM advantage, irrespective of encoding duration. These findings are inconsistent with a speed-of-processing account of this advantage. An alternative, attentional account, grounded in the existing literature on the visuo-cognitive consequences of video game play, is discussed.

Perception of Non-Native Consonant Length Contrast: The Role of Attention in Phonetic Processing

ERIC Educational Resources Information Center

Porretta, Vincent J.; Tucker, Benjamin V.

2015-01-01

The present investigation examines English speakers' ability to identify and discriminate non-native consonant length contrast. Three groups (L1 English No-Instruction, L1 English Instruction, and L1 Finnish control) performed a speeded forced-choice identification task and a speeded AX discrimination task on Finnish non-words (e.g.…

Large Grain Instruction and Phonological Awareness Skill Influence Rime Sensitivity, Processing Speed, and Early Decoding Skill in Adult L2 Learners

ERIC Educational Resources Information Center

Brennan, Christine; Booth, James R.

2015-01-01

Linguistic knowledge, cognitive ability, and instruction influence how adults acquire a second orthography yet it remains unclear how different forms of instruction influence grain size sensitivity and subsequent decoding skill and speed. Thirty-seven monolingual, literate English-speaking adults were trained on a novel artificial orthography…

Biocatalysis in the Pharmaceutical Industry: The Need for Speed

PubMed Central

2017-01-01

The use of biocatalysis in the pharmaceutical industry continues to expand as a result of increased access to enzymes and the ability to engineer those enzymes to meet the demands of industrial processes. However, we are still just scratching the surface of potential biocatalytic applications. The time pressures present in pharmaceutical process development are incompatible with the long lead times required for engineering a suitable biocatalyst. Dramatic increases in the speed of protein engineering are needed to deliver on the ever increasing opportunities for industrial biocatalytic processes. PMID:28523096

Biocatalysis in the Pharmaceutical Industry: The Need for Speed.

PubMed

Truppo, Matthew D

2017-05-11

The use of biocatalysis in the pharmaceutical industry continues to expand as a result of increased access to enzymes and the ability to engineer those enzymes to meet the demands of industrial processes. However, we are still just scratching the surface of potential biocatalytic applications. The time pressures present in pharmaceutical process development are incompatible with the long lead times required for engineering a suitable biocatalyst. Dramatic increases in the speed of protein engineering are needed to deliver on the ever increasing opportunities for industrial biocatalytic processes.

Motor demands impact speed of information processing in Autism Spectrum Disorders

PubMed Central

Kenworthy, Lauren; Yerys, Benjamin E.; Weinblatt, Rachel; Abrams, Danielle N.; Wallace, Gregory L.

2015-01-01

Objective The apparent contradiction between preserved or even enhanced perceptual processing speed on inspection time tasks in autism spectrum disorders (ASD) and impaired performance on complex processing speed tasks that require motor output (e.g. Wechsler Processing Speed Index) has not yet been systematically investigated. This study investigates whether adding motor output demands to an inspection time task impairs ASD performance compared to that of typically developing control (TDC) children. Method The performance of children with ASD (n=28; mean FSIQ=115) and TDC (n=25; mean FSIQ=122) children was compared on processing speed tasks with increasing motor demand. Correlations were run between ASD task performance and Autism Diagnostic Observation Schedule (ADOS) Communication scores. Results Performance by the ASD and TDC groups on a simple perceptual processing speed task with minimal motor demand was equivalent, though it diverged (ASD worse than TDC) on two tasks with the same stimuli, but increased motor output demands. ASD performance on the moderate but not the high speeded motor output demand task was negatively correlated with ADOS communication symptoms. Conclusions These data address the apparent contradiction between preserved inspection time in the context of slowed “processing speed” in ASD. They show that processing speed is preserved when motor demands are minimized, but that increased motor output demands interfere with the ability to act on perceptual processing of simple stimuli. Reducing motor demands (e.g. through the use of computers) may increase the capacity of people with ASD to demonstrate good perceptual processing in a variety of educational, vocational and social settings. PMID:23937483

Differential Response Speed: Is It Really a Nuisance?

ERIC Educational Resources Information Center

Jeon, Minjeong

2015-01-01

It is commonly acknowledged that ability and speed are not separate constructs but interact with each other. Traditionally, the ability-speed interplay has been seen as a problem to be conquered and a number of psychometric methods have been developed to deal with the interplay between ability and speed and to obtain more pure ability measures.…

A dynamic processes study of PM retention by trees under different wind conditions.

PubMed

Xie, Changkun; Kan, Liyan; Guo, Jiankang; Jin, Sijia; Li, Zhigang; Chen, Dan; Li, Xin; Che, Shengquan

2018-02-01

Particulate matter (PM) is one of the most serious environmental problems, exacerbating respiratory and vascular illnesses. Plants have the ability to reduce non-point source PM pollution through retention on leaves and branches. Studies of the dynamic processes of PM retention by plants and the mechanisms influencing this process will help to improve the efficiency of urban greening for PM reduction. We examined dynamic processes of PM retention and the major factors influencing PM retention by six trees with different branch structure characteristics in wind tunnel experiments at three different wind speeds. The results showed that the changes of PM numbers retained by plant leaves over time were complex dynamic processes for which maximum values could exceed minimum values by over 10 times. The average value of PM measured in multiple periods and situations can be considered a reliable indicator of the ability of the plant to retain PM. The dynamic processes were similar for PM 10 and PM 2.5 . They could be clustered into three groups simulated by continually-rising, inverse U-shaped, and U-shaped polynomial functions, respectively. The processes were the synthetic effect of characteristics such as species, wind speed, period of exposure and their interactions. Continually-rising functions always explained PM retention in species with extremely complex branch structure. Inverse U-shaped processes explained PM retention in species with relatively simple branch structure and gentle wind. The U-shaped processes mainly explained PM retention at high wind speeds and in species with a relatively simple crown. These results indicate that using plants with complex crowns in urban greening and decreasing wind speed in plant communities increases the chance of continually-rising or inverse U-shaped relationships, which have a positive effect in reducing PM pollution. Copyright © 2017 Elsevier Ltd. All rights reserved.

Some Viable Techniques for Assessing and Counselling Cognitive Processing Weakness

ERIC Educational Resources Information Center

Haruna, Abubakar Sadiq

2016-01-01

Cognitive Processing weakness (CPW) is a psychological problem that impedes students' ability to learn effectively in a normal school setting. Such weakness may include; auditory, visual, conceptual, sequential, speed and attention processing. This paper therefore examines the basic assessment or diagnostic approaches such as Diagnosis by…

Are Auditory and Visual Processing Deficits Related to Developmental Dyslexia?

ERIC Educational Resources Information Center

Georgiou, George K.; Papadopoulos, Timothy C.; Zarouna, Elena; Parrila, Rauno

2012-01-01

The purpose of this study was to examine if children with dyslexia learning to read a consistent orthography (Greek) experience auditory and visual processing deficits and if these deficits are associated with phonological awareness, rapid naming speed and orthographic processing. We administered measures of general cognitive ability, phonological…

Mental Abilities and School Achievement: A Test of a Mediation Hypothesis

ERIC Educational Resources Information Center

Vock, Miriam; Preckel, Franzis; Holling, Heinz

2011-01-01

This study analyzes the interplay of four cognitive abilities--reasoning, divergent thinking, mental speed, and short-term memory--and their impact on academic achievement in school in a sample of adolescents in grades seven to 10 (N = 1135). Based on information processing approaches to intelligence, we tested a mediation hypothesis, which states…

Gaining control: changing relations between executive control and processing speed and their relevance for mathematics achievement over course of the preschool period

PubMed Central

Clark, Caron A. C.; Nelson, Jennifer Mize; Garza, John; Sheffield, Tiffany D.; Wiebe, Sandra A.; Espy, Kimberly Andrews

2014-01-01

Early executive control (EC) predicts a range of academic outcomes and shows particularly strong associations with children's mathematics achievement. Nonetheless, a major challenge for EC research lies in distinguishing EC from related cognitive constructs that also are linked to achievement outcomes. Developmental cascade models suggest that children's information processing speed is a driving mechanism in cognitive development that supports gains in working memory, inhibitory control and associated cognitive abilities. Accordingly, individual differences in early executive task performance and their relation to mathematics may reflect, at least in part, underlying variation in children's processing speed. The aims of this study were to: (1) examine the degree of overlap between EC and processing speed at different preschool age points; and (2) determine whether EC uniquely predicts children's mathematics achievement after accounting for individual differences in processing speed. As part of a longitudinal, cohort-sequential study, 388 children (50% boys; 44% from low income households) completed the same battery of EC tasks at ages 3, 3.75, 4.5, and 5.25 years. Several of the tasks incorporated baseline speeded naming conditions with minimal EC demands. Multidimensional latent models were used to isolate the variance in executive task performance that did not overlap with baseline processing speed, covarying for child language proficiency. Models for separate age points showed that, while EC did not form a coherent latent factor independent of processing speed at age 3 years, it did emerge as a distinct factor by age 5.25. Although EC at age 3 showed no distinct relation with mathematics achievement independent of processing speed, EC at ages 3.75, 4.5, and 5.25 showed independent, prospective links with mathematics achievement. Findings suggest that EC and processing speed are tightly intertwined in early childhood. As EC becomes progressively decoupled from processing speed with age, it begins to take on unique, discriminative importance for children's mathematics achievement. PMID:24596563

Measuring Ability, Speed, or Both? Challenges, Psychometric Solutions, and What Can Be Gained from Experimental Control

ERIC Educational Resources Information Center

Goldhammer, Frank

2015-01-01

The main challenge of ability tests relates to the difficulty of items, whereas speed tests demand that test takers complete very easy items quickly. This article proposes a conceptual framework to represent how performance depends on both between-person differences in speed and ability and the speed-ability compromise within persons. Related…

Cognitive Risk Factors for Specific Learning Disorder: Processing Speed, Temporal Processing, and Working Memory.

PubMed

Moll, Kristina; Göbel, Silke M; Gooch, Debbie; Landerl, Karin; Snowling, Margaret J

2016-01-01

High comorbidity rates between reading disorder (RD) and mathematics disorder (MD) indicate that, although the cognitive core deficits underlying these disorders are distinct, additional domain-general risk factors might be shared between the disorders. Three domain-general cognitive abilities were investigated in children with RD and MD: processing speed, temporal processing, and working memory. Since attention problems frequently co-occur with learning disorders, the study examined whether these three factors, which are known to be associated with attention problems, account for the comorbidity between these disorders. The sample comprised 99 primary school children in four groups: children with RD, children with MD, children with both disorders (RD+MD), and typically developing children (TD controls). Measures of processing speed, temporal processing, and memory were analyzed in a series of ANCOVAs including attention ratings as covariate. All three risk factors were associated with poor attention. After controlling for attention, associations with RD and MD differed: Although deficits in verbal memory were associated with both RD and MD, reduced processing speed was related to RD, but not MD; and the association with RD was restricted to processing speed for familiar nameable symbols. In contrast, impairments in temporal processing and visuospatial memory were associated with MD, but not RD. © Hammill Institute on Disabilities 2014.

Planning or something else? Examining neuropsychological predictors of Zoo Map performance.

PubMed

Oosterman, Joukje M; Wijers, Marijn; Kessels, Roy P C

2013-01-01

The Zoo Map Test of the Behavioral Assessment of the Dysexecutive Syndrome battery is often applied to measure planning ability as part of executive function. Successful performance on this test is, however, dependent on various cognitive functions, and deficient Zoo Map performance does therefore not necessarily imply selectively disrupted planning abilities. To address this important issue, we examined whether planning is still the most important predictor of Zoo Map performance in a heterogeneous sample of neurologic and psychiatric outpatients (N = 71). In addition to the Zoo Map Test, the patients completed other neuropsychological tests of planning, inhibition, processing speed, and episodic memory. Planning was the strongest predictor of the total raw score and inappropriate places visited, and no additional contribution of other cognitive scores was found. One exception to this was the total time, which was associated with processing speed. Overall, our findings indicate that the Zoo Map Test is a valid indicator of planning ability in a heterogeneous patient sample.

White matter and information processing speed following treatment with cranial-spinal radiation for pediatric brain tumor.

PubMed

Scantlebury, Nadia; Bouffet, Eric; Laughlin, Suzanne; Strother, Douglas; McConnell, Dina; Hukin, Juliette; Fryer, Christopher; Laperriere, Normand; Montour-Proulx, Isabelle; Keene, Daniel; Fleming, Adam; Jabado, Nada; Liu, Fang; Riggs, Lily; Law, Nicole; Mabbott, Donald J

2016-05-01

We compared the structure of specific white matter tracts and information processing speed between children treated for posterior fossa tumors with cranial-spinal radiation (n = 30), or with surgery +/- focal radiation (n = 29), and healthy children (n = 37). Probabilistic diffusion tensor imaging (DTI) tractography was used to delineate the inferior longitudinal fasciculi, optic radiation, inferior frontal occipital fasciculi, and uncinate fasciculi bilaterally. Information processing speed was measured using the coding and symbol search subtests of the Wechsler Intelligence Scales, and visual matching, pair cancellation, and rapid picture naming subtests of the Woodcock-Johnson Test of Cognitive Ability, 3rd revision. We examined group differences using repeated measures MANOVAs and path analyses were used to test the relations between treatment, white matter structure of the tracts, and information processing speed. DTI indices of the optic radiations, the inferior longitudinal fasciculi, and the inferior fronto-occipital fasciculi differed between children treated with cranial-spinal radiation and children treated with surgery +/- focal radiation, and healthy controls (p = .045). Children treated with cranial-spinal radiation also exhibited lower processing speed scores relative to healthy control subjects (p = .002). Notably, we observed that group differences in information processing speed were related to the structure of the right optic radiation (p = .002). We show that cranial-spinal radiation may have a negative impact on information processing speed via insult to the right optic radiations. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Characterizing Literacy and Cognitive Function during Pregnancy and Postpartum.

PubMed

Yee, Lynn M; Kamel, Leslie A; Quader, Zara; Rajan, Priya V; Taylor, Shaneah M; O'Conor, Rachel; Wolf, Michael S; Simon, Melissa A

2017-07-01

Objective  The objective of this study was to characterize health literacy and cognitive function in a diverse cohort of pregnant women. Methods  Pregnant and postpartum women underwent in-depth assessments of health literacy/numeracy and the cognitive domains of verbal ability, working memory, long-term memory, processing speed, and inductive reasoning. Differences by demographic characteristics and gestational age were assessed using chi-square tests and multivariable logistic regression. Results  In this cohort of pregnant ( N  = 77) or postpartum ( N  = 24) women, 41.6% had limited health literacy/numeracy. Women were more likely to score in the lowest quartile for literacy and verbal ability if they were less educated, younger, nonwhite or had Medicaid. These factors were associated with low scores for long-term memory, processing speed, and inductive reasoning. Although there were no differences in literacy or cognitive function by parity or gestational age, postpartum women were more likely to score in the lowest quartile for processing speed (adjusted odds ratio [aOR]: 3.79, 95% confidence interval [CI]: 1.32-10.93) and inductive reasoning (aOR: 4.07, 95% CI: 1.21-13.70). Conclusion  Although postpartum status was associated with reduced inductive reasoning and processing speed, there were no differences in cognitive function across pregnancy. Practice Implications  Postpartum maternal learning may require enhanced support. In addition, cognitive skills and health literacy may be a mediator of perinatal outcomes inequities. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Development of Components of Reading Skill.

ERIC Educational Resources Information Center

Curtis, Mary E.

1980-01-01

Verbal coding and listening comprehension ability differed among skilled and less skilled readers in second, third, and fifth grades. As verbal coding speed increased, comprehension skill became the more important predictor of reading skill. Apparently, verbal coding processes, which are slow, inhibit other reading processes. (Author/CP)

Processing speed enhances model-based over model-free reinforcement learning in the presence of high working memory functioning

PubMed Central

Schad, Daniel J.; Jünger, Elisabeth; Sebold, Miriam; Garbusow, Maria; Bernhardt, Nadine; Javadi, Amir-Homayoun; Zimmermann, Ulrich S.; Smolka, Michael N.; Heinz, Andreas; Rapp, Michael A.; Huys, Quentin J. M.

2014-01-01

Theories of decision-making and its neural substrates have long assumed the existence of two distinct and competing valuation systems, variously described as goal-directed vs. habitual, or, more recently and based on statistical arguments, as model-free vs. model-based reinforcement-learning. Though both have been shown to control choices, the cognitive abilities associated with these systems are under ongoing investigation. Here we examine the link to cognitive abilities, and find that individual differences in processing speed covary with a shift from model-free to model-based choice control in the presence of above-average working memory function. This suggests shared cognitive and neural processes; provides a bridge between literatures on intelligence and valuation; and may guide the development of process models of different valuation components. Furthermore, it provides a rationale for individual differences in the tendency to deploy valuation systems, which may be important for understanding the manifold neuropsychiatric diseases associated with malfunctions of valuation. PMID:25566131

Sex Differences in Processing Speed: Developmental Effects in Males and Females

ERIC Educational Resources Information Center

Camarata, Stephen; Woodcock, Richard

2006-01-01

The purpose of this study was to compare the cognitive abilities and selected achievement performance of females and males across the lifespan on standardization samples of broad cognitive abilities in 1987 participants (1102 females, 885 males) from the WJ III, 4253 participants (2014 males, 2239 females) from the WJ-R, and 4225 participants…

Improved Processing Speed: Online Computer-Based Cognitive Training in Older Adults

ERIC Educational Resources Information Center

Simpson, Tamara; Camfield, David; Pipingas, Andrew; Macpherson, Helen; Stough, Con

2012-01-01

In an increasingly aging population, a number of adults are concerned about declines in their cognitive abilities. Online computer-based cognitive training programs have been proposed as an accessible means by which the elderly may improve their cognitive abilities; yet, more research is needed in order to assess the efficacy of these programs. In…

Reading comprehension skills of young adults with childhood diagnoses of dyslexia.

PubMed

Ransby, Marilyn J; Swanson, H Lee

2003-01-01

This study explores the contribution of cognitive processes to comprehension skills in adults who suffered from childhood developmental dyslexia (CD). The performance of adults with CD (ages 17 to 23), chronological age-matched (CA) adults, and reading level-matched (RL) children was compared on measures of phonological processing, naming speed, working memory (WM), general knowledge, vocabulary, and comprehension. The results showed that adults with CD scored lower on measures of phonological processing, naming speed, WM, general knowledge, and vocabulary when compared to CA readers but were comparable to RL children on the majority of process measures. Phonological processing, naming speed, vocabulary, general knowledge, and listening comprehension contributed independent variance to reading comprehension accuracy, whereas WM, intelligence, phonological processing, and listening comprehension contributed independent variance to comprehension fluency. Adults with CD scored lower than CA adults and higher than RL children on measures of lexical processing, WM, and listening comprehension when word recognition and intelligence were partialed from the analysis. In summary, constraints in phonological processing and naming speed mediate only some of the influence of high-order processes on reading comprehension. Furthermore, adults with CD experience difficulties in WM, listening comprehension, and vocabulary independently of their word recognition problems and intellectual ability.

Cognitive performance across the life course of Bolivian forager-farmers with limited schooling.

PubMed

Gurven, Michael; Fuerstenberg, Eric; Trumble, Benjamin; Stieglitz, Jonathan; Beheim, Bret; Davis, Helen; Kaplan, Hillard

2017-01-01

Cognitive performance is characterized by at least two distinct life course trajectories. Many cognitive abilities (e.g., "effortful processing" abilities, including fluid reasoning and processing speed) improve throughout early adolescence and start declining in early adulthood, whereas other abilities (e.g., "crystallized" abilities like vocabulary breadth) improve throughout adult life, remaining robust even at late ages. Although schooling may impact performance and cognitive "reserve," it has been argued that these age patterns of cognitive performance are human universals. Here we examine age patterns of cognitive performance among Tsimane forager-horticulturalists of Bolivia and test whether schooling is related to differences in cognitive performance over the life course to assess models of active versus passive cognitive reserve. We used a battery of eight tasks to assess a range of latent cognitive traits reflecting attention, processing speed, verbal declarative memory, and semantic fluency (n = 919 individuals, 49.9% female). Tsimane cognitive abilities show similar age-related differences as observed in industrialized populations: higher throughout adolescence and only slightly lower in later adulthood for semantic fluency but substantially lower performance beginning in early adulthood for all other abilities. Schooling is associated with greater cognitive abilities at all ages controlling for sex but has no attenuating effect on cognitive performance in late adulthood, consistent with models of passive cognitive reserve. We interpret the minimal attenuation of semantic fluency late in life in light of evolutionary theories of postreproductive life span, which emphasize indirect fitness contributions of older adults through the transfer of information, labor, and food to descendant kin. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Oxidative Stress, Motor Abilities, and Behavioral Adjustment in Children Treated for Acute Lymphoblastic Leukemia.

PubMed

Hockenberry, Marilyn J; Krull, Kevin R; Insel, Kathleen C; Harris, Lynnette L; Gundy, Patricia M; Adkins, Kristin B; Pasvogel, Alice E; Taylor, Olga A; Koerner, Kari M; Montgomery, David W; Ross, Adam K; Hill, Adam; Moore, Ida M

2015-09-01

To examine associations among oxidative stress, fine and visual-motor abilities, and behavioral adjustment in children receiving chemotherapy for acute lymphoblastic leukemia (ALL)
. A prospective, repeated-measures design
. Two pediatric oncology settings in the southwestern United States. 89 children with ALL were followed from diagnosis to the end of chemotherapy. Serial cerebrospinal fluid samples were collected during scheduled lumbar punctures and analyzed for oxidative stress biomarkers. Children completed fine motor dexterity, visual processing speed, and visual-motor integration measures at three time points. Parents completed child behavior ratings at the same times. Oxidative stress, fine motor dexterity, visual processing, visual-motor integration, and behavioral adjustment
. Children with ALL had below-average fine motor dexterity, visual processing speed, and visual-motor integration following the induction phase of ALL therapy. By end of therapy, visual processing speed normalized, and fine motor dexterity and visual-motor integration remained below average. Oxidative stress measures correlated with fine motor dexterity and visual-motor integration. Decreased motor functioning was associated with increased hyperactivity and anxiety
. Oxidative stress occurs following chemo-therapy for childhood ALL and is related to impaired fine motor skills and visual symptoms
. Early intervention should be considered to prevent fine motor and visual-spatial deficits, as well as behavioral problems.

A Measure of Inspection Time in 4-Year-Old Children: The Benny Bee IT Task

ERIC Educational Resources Information Center

Williams, Sarah E.; Turley, Christopher; Nettelbeck, Ted; Burns, Nicholas R.

2009-01-01

Inspection time (IT) measures speed of information processing without the confounding influence of motor speed. While IT has been found to relate to cognitive abilities in adults and older children, no measure of IT has been validated for use with children younger than 6 years. This study examined the validity of a new measure of IT for preschool…

How neuroscience can inform the study of individual differences in cognitive abilities

PubMed Central

McFarland, Dennis J.

2018-01-01

Theories of human mental abilities should be consistent with what is known in neuroscience. Currently tests of human mental abilities are modeled by cognitive constructs such as attention, working memory, and speed of information processing. These constructs are in turn related to a single general ability. However brains are very complex systems and whether most of the variability between the operations of different brains can be ascribed to a single factor is questionable. Research in neuroscience suggests that psychological processes such at perception, attention, decision and executive control are emergent properties of interacting distributed networks. The modules that make up these networks use similar computational processes that involve multiple forms of neural plasticity, each having different time constants. Accordingly these networks might best be characterized in terms of the information they process rather than in terms of abstract psychological processes such as working memory and executive control. PMID:28195556

Speed discrimination predicts word but not pseudo-word reading rate in adults and children

PubMed Central

Main, Keith L.; Pestilli, Franco; Mezer, Aviv; Yeatman, Jason; Martin, Ryan; Phipps, Stephanie; Wandell, Brian

2014-01-01

Word familiarity may affect magnocellular processes of word recognition. To explore this idea, we measured reading rate, speed-discrimination, and contrast detection thresholds in adults and children with a wide range of reading abilities. We found that speed-discrimination thresholds are higher in children than in adults and are correlated with age. Speed discrimination thresholds are also correlated with reading rate, but only for words, not for pseudo-words. Conversely, we found no correlation between contrast sensitivity and reading rate and no correlation between speed discrimination thresholds WASI subtest scores. These findings support the position that reading rate is influenced by magnocellular circuitry attuned to the recognition of familiar word-forms. PMID:25278418

Structural encoding processes contribute to individual differences in face and object cognition: Inferences from psychometric test performance and event-related brain potentials.

PubMed

Nowparast Rostami, Hadiseh; Sommer, Werner; Zhou, Changsong; Wilhelm, Oliver; Hildebrandt, Andrea

2017-10-01

The enhanced N1 component in event-related potentials (ERP) to face stimuli, termed N170, is considered to indicate the structural encoding of faces. Previously, individual differences in the latency of the N170 have been related to face and object cognition abilities. By orthogonally manipulating content domain (faces vs objects) and task demands (easy/speed vs difficult/accuracy) in both psychometric and EEG tasks, we investigated the uniqueness of the processes underlying face cognition as compared with object cognition and the extent to which the N1/N170 component can explain individual differences in face and object cognition abilities. Data were recorded from N = 198 healthy young adults. Structural equation modeling (SEM) confirmed that the accuracies of face perception (FP) and memory are specific abilities above general object cognition; in contrast, the speed of face processing was not differentiable from the speed of object cognition. Although there was considerable domain-general variance in the N170 shared with the N1, there was significant face-specific variance in the N170. The brain-behavior relationship showed that faster face-specific processes for structural encoding of faces are associated with higher accuracy in both perceiving and memorizing faces. Moreover, in difficult task conditions, qualitatively different processes are additionally needed for recognizing face and object stimuli as compared with easy tasks. The difficulty-dependent variance components in the N170 amplitude were related with both face and object memory (OM) performance. We discuss implications for understanding individual differences in face cognition. Copyright © 2017 Elsevier Ltd. All rights reserved.

Brain training game boosts executive functions, working memory and processing speed in the young adults: a randomized controlled trial.

PubMed

Nouchi, Rui; Taki, Yasuyuki; Takeuchi, Hikaru; Hashizume, Hiroshi; Nozawa, Takayuki; Kambara, Toshimune; Sekiguchi, Atsushi; Miyauchi, Carlos Makoto; Kotozaki, Yuka; Nouchi, Haruka; Kawashima, Ryuta

2013-01-01

Do brain training games work? The beneficial effects of brain training games are expected to transfer to other cognitive functions. Yet in all honesty, beneficial transfer effects of the commercial brain training games in young adults have little scientific basis. Here we investigated the impact of the brain training game (Brain Age) on a wide range of cognitive functions in young adults. We conducted a double-blind (de facto masking) randomized controlled trial using a popular brain training game (Brain Age) and a popular puzzle game (Tetris). Thirty-two volunteers were recruited through an advertisement in the local newspaper and randomly assigned to either of two game groups (Brain Age, Tetris). Participants in both the Brain Age and the Tetris groups played their game for about 15 minutes per day, at least 5 days per week, for 4 weeks. Measures of the cognitive functions were conducted before and after training. Measures of the cognitive functions fell into eight categories (fluid intelligence, executive function, working memory, short-term memory, attention, processing speed, visual ability, and reading ability). Our results showed that commercial brain training game improves executive functions, working memory, and processing speed in young adults. Moreover, the popular puzzle game can engender improvement attention and visuo-spatial ability compared to playing the brain training game. The present study showed the scientific evidence which the brain training game had the beneficial effects on cognitive functions (executive functions, working memory and processing speed) in the healthy young adults. Our results do not indicate that everyone should play brain training games. However, the commercial brain training game might be a simple and convenient means to improve some cognitive functions. We believe that our findings are highly relevant to applications in educational and clinical fields. UMIN Clinical Trial Registry 000005618.

The impact of social activities, social networks, social support and social relationships on the cognitive functioning of healthy older adults: a systematic review.

PubMed

Kelly, Michelle E; Duff, Hollie; Kelly, Sara; McHugh Power, Joanna E; Brennan, Sabina; Lawlor, Brian A; Loughrey, David G

2017-12-19

Social relationships, which are contingent on access to social networks, promote engagement in social activities and provide access to social support. These social factors have been shown to positively impact health outcomes. In the current systematic review, we offer a comprehensive overview of the impact of social activities, social networks and social support on the cognitive functioning of healthy older adults (50+) and examine the differential effects of aspects of social relationships on various cognitive domains. We followed PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines, and collated data from randomised controlled trials (RCTs), genetic and observational studies. Independent variables of interest included subjective measures of social activities, social networks, and social support, and composite measures of social relationships (CMSR). The primary outcome of interest was cognitive function divided into domains of episodic memory, semantic memory, overall memory ability, working memory, verbal fluency, reasoning, attention, processing speed, visuospatial abilities, overall executive functioning and global cognition. Thirty-nine studies were included in the review; three RCTs, 34 observational studies, and two genetic studies. Evidence suggests a relationship between (1) social activity and global cognition and overall executive functioning, working memory, visuospatial abilities and processing speed but not episodic memory, verbal fluency, reasoning or attention; (2) social networks and global cognition but not episodic memory, attention or processing speed; (3) social support and global cognition and episodic memory but not attention or processing speed; and (4) CMSR and episodic memory and verbal fluency but not global cognition. The results support prior conclusions that there is an association between social relationships and cognitive function but the exact nature of this association remains unclear. Implications of the findings are discussed and suggestions for future research provided. PROSPERO 2012: CRD42012003248 .

Brain Training Game Boosts Executive Functions, Working Memory and Processing Speed in the Young Adults: A Randomized Controlled Trial

PubMed Central

Nouchi, Rui; Taki, Yasuyuki; Takeuchi, Hikaru; Hashizume, Hiroshi; Nozawa, Takayuki; Kambara, Toshimune; Sekiguchi, Atsushi; Miyauchi, Carlos Makoto; Kotozaki, Yuka; Nouchi, Haruka; Kawashima, Ryuta

2013-01-01

Background Do brain training games work? The beneficial effects of brain training games are expected to transfer to other cognitive functions. Yet in all honesty, beneficial transfer effects of the commercial brain training games in young adults have little scientific basis. Here we investigated the impact of the brain training game (Brain Age) on a wide range of cognitive functions in young adults. Methods We conducted a double-blind (de facto masking) randomized controlled trial using a popular brain training game (Brain Age) and a popular puzzle game (Tetris). Thirty-two volunteers were recruited through an advertisement in the local newspaper and randomly assigned to either of two game groups (Brain Age, Tetris). Participants in both the Brain Age and the Tetris groups played their game for about 15 minutes per day, at least 5 days per week, for 4 weeks. Measures of the cognitive functions were conducted before and after training. Measures of the cognitive functions fell into eight categories (fluid intelligence, executive function, working memory, short-term memory, attention, processing speed, visual ability, and reading ability). Results and Discussion Our results showed that commercial brain training game improves executive functions, working memory, and processing speed in young adults. Moreover, the popular puzzle game can engender improvement attention and visuo-spatial ability compared to playing the brain training game. The present study showed the scientific evidence which the brain training game had the beneficial effects on cognitive functions (executive functions, working memory and processing speed) in the healthy young adults. Conclusions Our results do not indicate that everyone should play brain training games. However, the commercial brain training game might be a simple and convenient means to improve some cognitive functions. We believe that our findings are highly relevant to applications in educational and clinical fields. Trial Registration UMIN Clinical Trial Registry 000005618. PMID:23405164

Large grain instruction and phonological awareness skill influence rime sensitivity, processing speed, and early decoding skill in adult L2 learners

PubMed Central

Brennan, Christine; Booth, James R.

2016-01-01

Linguistic knowledge, cognitive ability, and instruction influence how adults acquire a second orthography yet it remains unclear how different forms of instruction influence grain size sensitivity and subsequent decoding skill and speed. Thirty-seven monolingual, literate English-speaking adults were trained on a novel artificial orthography given initial instruction that directed attention to either large or small grain size units (i.e., words or letters). We examined how initial instruction influenced processing speed (i.e., reaction time (RT)) and sensitivity to different orthographic grain sizes (i.e., rimes and letters). Directing attention to large grain size units during initial instruction resulted in higher accuracy for rimes, whereas directing attention to smaller grain size units resulted in slower RTs across all measures. Additionally, phonological awareness skill modulated early learning effects, compensating for the limitations of the initial instruction provided. Collectively, these findings suggest that when adults are learning to read a second orthography, consideration should be given to how initial instruction directs attention to different grain sizes and inherent phonological awareness ability. PMID:27829705

Numerical Processing Efficiency Improved in Experienced Mental Abacus Children

ERIC Educational Resources Information Center

Wang, Yunqi; Geng, Fengji; Hu, Yuzheng; Du, Fenglei; Chen, Feiyan

2013-01-01

Experienced mental abacus (MA) users are able to perform mental arithmetic calculations with unusual speed and accuracy. However, it remains unclear whether their extraordinary gains in mental arithmetic ability are accompanied by an improvement in numerical processing efficiency. To address this question, the present study, using a numerical…

Visual Processing Deficits in Children with Slow RAN Performance

ERIC Educational Resources Information Center

Stainthorp, Rhona; Stuart, Morag; Powell, Daisy; Quinlan, Philip; Garwood, Holly

2010-01-01

Two groups of 8- to 10-year-olds differing in rapid automatized naming speed but matched for age, verbal and nonverbal ability, phonological awareness, phonological memory, and visual acuity participated in four experiments investigating early visual processing. As low RAN children had significantly slower simple reaction times (SRT) this was…

The Impact of Feedback on Self-Rated Driving Ability and Driving Self-Regulation among Older Adults

ERIC Educational Resources Information Center

Ackerman, Michelle L.; Crowe, Michael; Vance, David E.; Wadley, Virginia G.; Owsley, Cynthia; Ball, Karlene K.

2011-01-01

In 129 community-dwelling older adults, feedback regarding qualification for an insurance discount (based on a visual speed of processing test; Useful Field of View) was examined as a prospective predictor of change in self-reported driving ability, driving avoidance, and driving exposure over 3 months, along with physical, visual, health, and…

WISC-IV Profile in High-Functioning Autism Spectrum Disorders: Impaired Processing Speed Is Associated with Increased Autism Communication Symptoms and Decreased Adaptive Communication Abilities

ERIC Educational Resources Information Center

Oliveras-Rentas, Rafael E.; Kenworthy, Lauren; Roberson, Richard B.; Martin, Alex; Wallace, Gregory L.

2012-01-01

Changes in the Wechsler Intelligence Scales for Children-IV (WISC-IV) may affect the IQ profile characteristic of autism spectrum disorders (ASD). Moreover, the association of particular component cognitive abilities (unlike overall IQ) with symptomatology and adaptive functioning in ASD remains unclear. This archival study characterizes the…

Basic Information Processing Abilities at 11 years Account for Deficits in IQ Associated with Preterm Birth.

PubMed

Rose, Susan A; Feldman, Judith F; Jankowski, Jeffery J; Van Rossem, Ronan

2011-07-01

Although it is well established that preterms as a group do poorly relative to their full-term peers on tests of global cognitive functioning, the basis for this relative deficiency is less understood. The present paper examines preterm deficits in core cognitive abilities and determines their role in mediating preterm/full-term differences in IQ. The performance of 11-year-old children born preterm (birth weight <1750g) and their full-term controls were compared on a large battery of 15 tasks, covering four basic cognitive domains -- memory, attention, speed of processing and representational competence. The validity of these four domains was established using latent variables and confirmatory factor analysis (CFA). Preterms showed pervasive deficits within and across domains. Additionally, preterm deficits in IQ were completely mediated by these four cognitive domains in a structural equation model involving a cascade from elementary abilities (attention and speed), to more complex abilities (memory and representational competence), to IQ. The similarity of findings to those obtained with this cohort in infancy and toddlerhood suggest that preterm deficits persist - across time, across task, and from the non-verbal to the verbal period.

Basic Information Processing Abilities at 11 years Account for Deficits in IQ Associated with Preterm Birth

PubMed Central

Rose, Susan A.; Feldman, Judith F.; Jankowski, Jeffery J.; Van Rossem, Ronan

2011-01-01

Although it is well established that preterms as a group do poorly relative to their full-term peers on tests of global cognitive functioning, the basis for this relative deficiency is less understood. The present paper examines preterm deficits in core cognitive abilities and determines their role in mediating preterm/full-term differences in IQ. The performance of 11-year-old children born preterm (birth weight <1750g) and their full-term controls were compared on a large battery of 15 tasks, covering four basic cognitive domains -- memory, attention, speed of processing and representational competence. The validity of these four domains was established using latent variables and confirmatory factor analysis (CFA). Preterms showed pervasive deficits within and across domains. Additionally, preterm deficits in IQ were completely mediated by these four cognitive domains in a structural equation model involving a cascade from elementary abilities (attention and speed), to more complex abilities (memory and representational competence), to IQ. The similarity of findings to those obtained with this cohort in infancy and toddlerhood suggest that preterm deficits persist – across time, across task, and from the non-verbal to the verbal period. PMID:21643482

Information Processing in Toddlers: Continuity from Infancy and Persistence of Preterm Deficits

ERIC Educational Resources Information Center

Rose, Susan A.; Feldman, Judith F.; Jankowski, Jeffery J.

2009-01-01

The present report assesses information processing in the toddler years (24 and 36 months), using a cohort of preterms (less than 1750 g) and full-terms initially seen in infancy. The children received a battery of tasks tapping 11 specific abilities from four domains--memory, processing speed, attention, and representational competence. The same…

Age Effects in Information Processing.

ERIC Educational Resources Information Center

Furukawa, James M.; And Others

Attempts to modify or ameliorate the effects of declining cognitive abilities of the elderly have met with limited success. To focus on the effects of age in cognitive processing capacity (CPC), Furukawa's (1977) CPC test was administered individually to 3 age groups (16-30, 31-45, and 45-60) of 15 subjects each. Speed of processing old and new…

The Complexities of Complex Memory Span: Storage and Processing Deficits in Specific Language Impairment

ERIC Educational Resources Information Center

Archibald, Lisa M. D.; Gathercole, Susan E.

2007-01-01

This study investigated the verbal and visuospatial processing and storage skills of children with SLI and typically developing children. Fourteen school-age children with SLI, and two groups of typically developing children matched either for age or language abilities, completed measures of processing speed and storage capacity, and a set of…

Real-time polarization-sensitive optical coherence tomography data processing with parallel computing

PubMed Central

Liu, Gangjun; Zhang, Jun; Yu, Lingfeng; Xie, Tuqiang; Chen, Zhongping

2010-01-01

With the increase of the A-line speed of optical coherence tomography (OCT) systems, real-time processing of acquired data has become a bottleneck. The shared-memory parallel computing technique is used to process OCT data in real time. The real-time processing power of a quad-core personal computer (PC) is analyzed. It is shown that the quad-core PC could provide real-time OCT data processing ability of more than 80K A-lines per second. A real-time, fiber-based, swept source polarization-sensitive OCT system with 20K A-line speed is demonstrated with this technique. The real-time 2D and 3D polarization-sensitive imaging of chicken muscle and pig tendon is also demonstrated. PMID:19904337

A learning-based autonomous driver: emulate human driver's intelligence in low-speed car following

NASA Astrophysics Data System (ADS)

Wei, Junqing; Dolan, John M.; Litkouhi, Bakhtiar

2010-04-01

In this paper, an offline learning mechanism based on the genetic algorithm is proposed for autonomous vehicles to emulate human driver behaviors. The autonomous driving ability is implemented based on a Prediction- and Cost function-Based algorithm (PCB). PCB is designed to emulate a human driver's decision process, which is modeled as traffic scenario prediction and evaluation. This paper focuses on using a learning algorithm to optimize PCB with very limited training data, so that PCB can have the ability to predict and evaluate traffic scenarios similarly to human drivers. 80 seconds of human driving data was collected in low-speed (< 30miles/h) car-following scenarios. In the low-speed car-following tests, PCB was able to perform more human-like carfollowing after learning. A more general 120 kilometer-long simulation showed that PCB performs robustly even in scenarios that are not part of the training set.

Does participation in art classes influence performance on two different cognitive tasks?

PubMed

Schindler, Manuel; Maihöfner, Christian; Bolwerk, Anne; Lang, Frieder R

2017-04-01

Effects of two mentally stimulating art interventions on processing speed and visuo-spatial cognition were compared in three samples. In a randomized 10-week art intervention study with a pre-post follow-up design, 113 adults (27 healthy older adults with subjective memory complaints, 50 healthy older adults and 36 healthy younger adults) were randomly assigned to one of two groups: visual art production or cognitive art evaluation, where the participants either produced or evaluated art. ANOVAs with repeated measures were computed to observe effects on the Symbol-Digit Test, and the Stick Test. Significant Time effects were found with regard to processing speed and visuo-spatial cognition. Additionally, there was found a significant Time × Sample interaction for processing speed. The effects proved robust after testing for education and adding sex as additional factor. Mental stimulation by participation in art classes leads to an improvement of processing speed and visuo-spatial cognition. Further investigation is required to improve understanding of the potential impact of art intervention on cognitive abilities across adulthood.

Adaptive-optics optical coherence tomography processing using a graphics processing unit.

PubMed

Shafer, Brandon A; Kriske, Jeffery E; Kocaoglu, Omer P; Turner, Timothy L; Liu, Zhuolin; Lee, John Jaehwan; Miller, Donald T

2014-01-01

Graphics processing units are increasingly being used for scientific computing for their powerful parallel processing abilities, and moderate price compared to super computers and computing grids. In this paper we have used a general purpose graphics processing unit to process adaptive-optics optical coherence tomography (AOOCT) images in real time. Increasing the processing speed of AOOCT is an essential step in moving the super high resolution technology closer to clinical viability.

Utility of the General Ability Index (GAI) and Cognitive Proficiency Index (CPI) with Survivors of Pediatric Brain Tumors: Comparison to Full Scale IQ and Premorbid IQ Estimates

PubMed Central

Kahalley, Lisa S.; Winter-Greenberg, Amanda; Stancel, Heather; Ris, M. Douglas; Gragert, Marsha

2016-01-01

Introduction Pediatric brain tumor survivors are at risk for working memory and processing speed impairment. The General Ability Index (GAI) provides an estimate of intellectual functioning that is less influenced by working memory and processing speed than a Full Scale IQ (FSIQ). The Cognitive Proficiency Index (CPI) provides a measure of efficient information processing derived from working memory and processing speed tasks. We examined the utility of the GAI and CPI to quantify neurocognitive outcomes in a sample of pediatric brain tumor survivors. Methods GAI, CPI, and FSIQ scores from the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV) were examined for 57 pediatric brain tumor survivors (ages 6–16) treated with cranial radiation therapy (RT). Results GAI scores were higher than FSIQ and CPI scores, both p < .001. Lower CPI scores were associated with history of craniospinal irradiation and time since RT. Lower FSIQ and GAI scores were associated with higher RT dose and time since RT. The rate of clinically significant GAI-FSIQ discrepancies in our sample was greater than observed in the WISC-IV standardization sample, p < .001. Estimated premorbid IQ scores were higher than GAI, p < .01, and FSIQ scores, p < .001. Conclusions Pediatric brain tumor survivors exhibit weaker cognitive proficiency than expected for age, while general reasoning ability remains relatively spared. The GAI may be useful to quantify the intellectual potential of a survivor when appropriate accommodations are in place for relative cognitive proficiency weaknesses. The CPI may be a particularly sensitive outcome measure of treatment-related cognitive change in this population. PMID:27295192

Cohort Differences in Cognitive Aging in the Longitudinal Aging Study Amsterdam.

PubMed

Brailean, Anamaria; Huisman, Martijn; Prince, Martin; Prina, A Matthew; Deeg, Dorly J H; Comijs, Hannie

2016-09-30

This study aims to examine cohort differences in cognitive performance and rates of change in episodic memory, processing speed, inductive reasoning, and general cognitive performance and to investigate whether these cohort effects may be accounted for by education attainment. The first cohort (N = 705) was born between 1920 and 1930, whereas the second cohort (N = 646) was born between 1931 and 1941. Both birth cohorts were aged 65 to 75 years at baseline and were followed up 3 and 6 years later. Data were analyzed using linear mixed models. The later born cohort had better general cognitive performance, inductive reasoning, and processing speed at baseline, but cohort differences in inductive reasoning and general cognitive performance disappeared after adjusting for education. The later born cohort showed steeper decline in processing speed. Memory decline was steeper in the earlier born cohort but only from Time 1 to Time 3 when the same memory test was administered. Education did not account for cohort differences in cognitive decline. The later born cohort showed better initial performance in certain cognitive abilities, but no better preservation of cognitive abilities overtime compared with the earlier born cohort. These findings carry implications for healthy cognitive aging. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America.

Training and Older Workers: Implications for U.S. Competitiveness. Contract Report.

ERIC Educational Resources Information Center

Rothstein, Frances R.; Ratte, Donna J.

Age-related changes in functional ability and work attitude affect job performance, but many variables affect the extent and timing of change for different older workers. Declines due to age occur in sensory/perceptual processes; strength, speed and accuracy of movement, and balance; and cognitive processes. Individuals can compensate for some…

Cognitive Risk Factors for Specific Learning Disorder: Processing Speed, Temporal Processing, and Working Memory

ERIC Educational Resources Information Center

Moll, Kristina; Göbel, Silke M.; Gooch, Debbie; Landerl, Karin; Snowling, Margaret J.

2016-01-01

High comorbidity rates between reading disorder (RD) and mathematics disorder (MD) indicate that, although the cognitive core deficits underlying these disorders are distinct, additional domain-general risk factors might be shared between the disorders. Three domain-general cognitive abilities were investigated in children with RD and MD:…

Cognitive Proficiency Index for the Canadian Edition of the Wechsler Intelligence Scale for Children-Fourth Edition

ERIC Educational Resources Information Center

Saklofske, Donald H.; Zhu, Jianjun; Coalson, Diane L.; Raiford, Susan E.; Weiss, Lawrence G.

2010-01-01

The Cognitive Proficiency Index (CPI) developed for the most recent Wechsler intelligence scales comprises the working memory and processing speed subtests. It reflects the proficiency and efficiency of cognitive processing and provides another lens for analyzing children's abilities assessed by the Wechsler Intelligence Scale for Children--Fourth…

A Tablet for Healthy Ageing: The Effect of a Tablet Computer Training Intervention on Cognitive Abilities in Older Adults.

PubMed

Vaportzis, Eleftheria; Martin, Mike; Gow, Alan J

2017-08-01

To test the efficacy of a tablet computer training intervention to improve cognitive abilities of older adults. Prospective randomized controlled trial. Community-based aging intervention study, Edinburgh, UK. Forty-eight healthy older adults aged 65 to 76 years were recruited at baseline with no or minimal tablet experience; 43 completed follow-up testing. Twenty-two participants attended a weekly 2-hour class for 10 weeks during which they learned how to use a tablet and various applications on it. A battery of cognitive tests from the WAIS-IV measuring the domains of Verbal Comprehension, Perceptual Processing, Working Memory, and Processing Speed, as well as health, psychological, and well-being measures. A 2 × 2 mixed model ANOVA suggested that the tablet intervention group (N = 22) showed greater improvements in Processing Speed (η 2  = 0.10) compared with controls (N = 21), but did not differ in Verbal Comprehension, Perceptual Processing, or Working Memory (η 2 ranged from -0.03 to 0.04). Engagement in a new mentally challenging activity (tablet training) was associated with improved processing speed. Acquiring skills in later life, including those related to adopting new technologies, may therefore have the potential to reduce or delay cognitive changes associated with ageing. It is important to understand how the development of these skills might further facilitate everyday activities, and also improve older adults' quality of life. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Goal neglect, fluid intelligence and processing speed: Manipulating instruction load and inter-stimulus interval.

PubMed

Iveson, Matthew H; Della Sala, Sergio; Anderson, Mike; MacPherson, Sarah E

2017-05-01

Goal maintenance is the process where task rules and instructions are kept active to exert their control on behavior. When this process fails, an individual may ignore a rule while performing the task, despite being able to describe it after task completion. Previous research has suggested that the goal maintenance system is limited by the number of concurrent rules which can be maintained during a task, and that this limit is dependent on an individual's level of fluid intelligence. However, the speed at which an individual can process information may also limit their ability to use task rules when the task demands them. In the present study, four experiments manipulated the number of instructions to be maintained by younger and older adults and examined whether performance on a rapid letter-monitoring task was predicted by individual differences in fluid intelligence or processing speed. Fluid intelligence played little role in determining how frequently rules were ignored during the task, regardless of the number of rules to be maintained. In contrast, processing speed predicted the rate of goal neglect in older adults, where increasing the presentation rate of the letter-monitoring task increased goal neglect. These findings suggest that goal maintenance may be limited by the speed at which it can operate. Copyright © 2017. Published by Elsevier B.V.

Cognitive Processing Speed, Working Memory, and the Intelligibility of Hearing Aid-Processed Speech in Persons with Hearing Impairment

PubMed Central

Yumba, Wycliffe Kabaywe

2017-01-01

Previous studies have demonstrated that successful listening with advanced signal processing in digital hearing aids is associated with individual cognitive capacity, particularly working memory capacity (WMC). This study aimed to examine the relationship between cognitive abilities (cognitive processing speed and WMC) and individual listeners’ responses to digital signal processing settings in adverse listening conditions. A total of 194 native Swedish speakers (83 women and 111 men), aged 33–80 years (mean = 60.75 years, SD = 8.89), with bilateral, symmetrical mild to moderate sensorineural hearing loss who had completed a lexical decision speed test (measuring cognitive processing speed) and semantic word-pair span test (SWPST, capturing WMC) participated in this study. The Hagerman test (capturing speech recognition in noise) was conducted using an experimental hearing aid with three digital signal processing settings: (1) linear amplification without noise reduction (NoP), (2) linear amplification with noise reduction (NR), and (3) non-linear amplification without NR (“fast-acting compression”). The results showed that cognitive processing speed was a better predictor of speech intelligibility in noise, regardless of the types of signal processing algorithms used. That is, there was a stronger association between cognitive processing speed and NR outcomes and fast-acting compression outcomes (in steady state noise). We observed a weaker relationship between working memory and NR, but WMC did not relate to fast-acting compression. WMC was a relatively weaker predictor of speech intelligibility in noise. These findings might have been different if the participants had been provided with training and or allowed to acclimatize to binary masking noise reduction or fast-acting compression. PMID:28861009

The puzzle of processing speed, memory, and executive function impairments in schizophrenia: fitting the pieces together.

PubMed

Knowles, Emma E M; Weiser, Mark; David, Anthony S; Glahn, David C; Davidson, Michael; Reichenberg, Abraham

2015-12-01

Substantial impairment in performance on the digit-symbol substitution task in patients with schizophrenia is well established, which has been widely interpreted as denoting a specific impairment in processing speed. However, other higher order cognitive functions might be more critical to performance on this task. To date, this idea has not been rigorously investigated in patients with schizophrenia. Neuropsychological measures of processing speed, memory, and executive functioning were completed by 125 patients with schizophrenia and 272 control subjects. We implemented a series of confirmatory factor and structural regression modeling to build an integrated model of processing speed, memory, and executive function with which to deconstruct the digit-symbol substitution task and characterize discrepancies between patients with schizophrenia and control subjects. The overall structure of the processing speed, memory, and executive function model was the same across groups (χ(2) = 208.86, p > .05), but the contribution of the specific cognitive domains to coding task performance differed significantly. When completing the task, control subjects relied on executive function and, indirectly, on working memory ability, whereas patients with schizophrenia used an alternative set of cognitive operations whereby they relied on the same processes required to complete verbal fluency tasks. Successful coding task performance relies predominantly on executive function, rather than processing speed or memory. Patients with schizophrenia perform poorly on this task because of an apparent lack of appropriate executive function input; they rely instead on an alternative cognitive pathway. Copyright © 2015 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Dietary patterns and cognitive ability among 12- to 13 year-old adolescents in Selangor, Malaysia.

PubMed

Nurliyana, Abdul Razak; Mohd Nasir, Mohd Taib; Zalilah, Mohd Shariff; Rohani, Abdullah

2015-02-01

The present study aimed to identify dietary patterns and determine the relationship between dietary patterns and cognitive ability among 12- to 13 year-old Malay adolescents in the urban areas of Gombak district in Selangor, Malaysia. Data on sociodemographic background were obtained from parents. Height and weight were measured and BMI-for-age was determined. Adolescents were interviewed on their habitual dietary intakes using a semi-quantitative FFQ. Cognitive ability was assessed using the Wechsler Nonverbal Scale of Ability in a one-to-one manner. Dietary patterns were constructed using principal component analysis based on thirty-eight food groups of the semi-quantitative FFQ. Urban secondary public schools in the district of Gombak in Selangor, Malaysia. Malay adolescents aged 12 to 13 years (n 416). The mean general cognitive ability score was 101·8 (sd 12·4). Four major dietary patterns were identified and labelled as 'refined-grain pattern', 'snack-food pattern', 'plant-based food pattern' and 'high-energy food pattern'. These dietary patterns explained 39·1 % of the variance in the habitual dietary intakes of the adolescents. The refined-grain pattern was negatively associated with processing speed, which is a construct of general cognitive ability. The high-energy food pattern was negatively associated with general cognitive ability, perceptual reasoning and processing speed. Monthly household income and parents' educational attainment were positively associated with all of the cognitive measures. In multivariate analysis, only the high-energy food pattern was found to contribute significantly towards general cognitive ability after controlling for socio-economic status. Consumption of foods in the high-energy food pattern contributed towards general cognitive ability after controlling for socio-economic status. However, the contribution was small.

Latent change models of adult cognition: are changes in processing speed and working memory associated with changes in episodic memory?

PubMed

Hertzog, Christopher; Dixon, Roger A; Hultsch, David F; MacDonald, Stuart W S

2003-12-01

The authors used 6-year longitudinal data from the Victoria Longitudinal Study (VLS) to investigate individual differences in amount of episodic memory change. Latent change models revealed reliable individual differences in cognitive change. Changes in episodic memory were significantly correlated with changes in other cognitive variables, including speed and working memory. A structural equation model for the latent change scores showed that changes in speed and working memory predicted changes in episodic memory, as expected by processing resource theory. However, these effects were best modeled as being mediated by changes in induction and fact retrieval. Dissociations were detected between cross-sectional ability correlations and longitudinal changes. Shuffling the tasks used to define the Working Memory latent variable altered patterns of change correlations.

Learning to Control Actions: Transfer Effects following a Procedural Cognitive Control Computerized Training

PubMed Central

Shahar, Nitzan; Meiran, Nachshon

2015-01-01

Few studies have addressed action control training. In the current study, participants were trained over 19 days in an adaptive training task that demanded constant switching, maintenance and updating of novel action rules. Participants completed an executive functions battery before and after training that estimated processing speed, working memory updating, set-shifting, response inhibition and fluid intelligence. Participants in the training group showed greater improvement than a no-contact control group in processing speed, indicated by reduced reaction times in speeded classification tasks. No other systematic group differences were found across the different pre-post measurements. Ex-Gaussian fitting of the reaction-time distribution revealed that the reaction time reduction observed among trained participants was restricted to the right tail of the distribution, previously shown to be related to working memory. Furthermore, training effects were only found in classification tasks that required participants to maintain novel stimulus-response rules in mind, supporting the notion that the training improved working memory abilities. Training benefits were maintained in a 10-month follow-up, indicating relatively long-lasting effects. The authors conclude that training improved action-related working memory abilities. PMID:25799443

High-speed spectral domain optical coherence tomography using non-uniform fast Fourier transform

PubMed Central

Chan, Kenny K. H.; Tang, Shuo

2010-01-01

The useful imaging range in spectral domain optical coherence tomography (SD-OCT) is often limited by the depth dependent sensitivity fall-off. Processing SD-OCT data with the non-uniform fast Fourier transform (NFFT) can improve the sensitivity fall-off at maximum depth by greater than 5dB concurrently with a 30 fold decrease in processing time compared to the fast Fourier transform with cubic spline interpolation method. NFFT can also improve local signal to noise ratio (SNR) and reduce image artifacts introduced in post-processing. Combined with parallel processing, NFFT is shown to have the ability to process up to 90k A-lines per second. High-speed SD-OCT imaging is demonstrated at camera-limited 100 frames per second on an ex-vivo squid eye. PMID:21258551

Predicting Word Reading and Comprehension with Executive Function and Speed Measures Across Development: A Latent Variable Analysis

PubMed Central

Christopher, Micaela E.; Miyake, Akira; Keenan, Janice M.; Pennington, Bruce; DeFries, John C.; Wadsworth, Sally J.; Willcutt, Erik; Olson, Richard K.

2012-01-01

The present study explored whether different executive control and speed measures (working memory, inhibition, processing speed, and naming speed) independently predict individual differences in word reading and reading comprehension. Although previous studies suggest these cognitive constructs are important for reading, we analyze the constructs simultaneously to test whether each is a unique predictor. We used latent variables from 483 participants (ages 8 to 16) to portion each cognitive and reading construct into its unique and shared variance. In these models we address two specific issues: (a) given that our wide age range may span the theoretical transition from “learning to read” to “reading to learn,” we first test whether the relation between word reading and reading comprehension is stable across two age groups (ages 8 to 10 and 11 to 16); and (b) the main theoretical question of interest: whether what is shared and what is separable for word reading and reading comprehension are associated with individual differences in working memory, inhibition, and measures of processing and naming speed. The results indicated that: (a) the relation between word reading and reading comprehension is largely invariant across the age groups; (b) working memory and general processing speed, but not inhibition or the speeded naming of non-alphanumeric stimuli, are unique predictors of both word reading and comprehension, with working memory equally important for both reading abilities and processing speed more important for word reading. These results have implications for understanding why reading comprehension and word reading are highly correlated yet separable. PMID:22352396

Phonological Processing Skills as Predictors of Literacy amongst Arabic Speaking Bahraini Children

ERIC Educational Resources Information Center

al Mannai, Haya; Everatt, John

2005-01-01

This paper reports a study of the reading and spelling skills of grades 1-3 Arabic-speaking children in Bahrain. Children were tested on their literacy skills (single word reading and spelling), their ability to decode letter strings (non-word reading) and measures of phonological awareness, short-term memory, speed of processing and non-verbal…

An Information-Processing Approach to the Development of Reading for Comprehension. Final Report.

ERIC Educational Resources Information Center

Schadler, Margaret; Juola, James F.

This paper is a summary of research on the perceptual and memory processes related to reading, their developmental progress in children, and the reading abilities in adults. Reported among the results of the various studies are the following: (1) developmental changes in reading after second grade primarily improve speed of coding, (2) reading…

Cognitive performance across the life course of Bolivian forager-farmers with limited schooling

PubMed Central

Gurven, Michael; Fuerstenberg, Eric; Trumble, Ben; Stieglitz, Jonathan; Beheim, Bret; Davis, Helen; Kaplan, Hillard

2016-01-01

Cognitive performance is characterized by at least two distinct life course trajectories. Many cognitive abilities (e.g. “effortful processing” abilities including fluid reasoning, and processing speed) improve throughout early adolescence and start declining in early adulthood, while other abilities (e.g. “crystallized” abilities like vocabulary breadth) improve throughout adult life, remaining robust even at late ages. Although schooling may impact performance and cognitive “reserve”, it has been argued that these age patterns of cognitive performance are human universals. Here we examine age patterns of cognitive performance among Tsimane forager-horticulturalists of Bolivia, and test whether schooling is related to differences in cognitive performance over the life course to assess models of active vs. passive cognitive reserve. We used a battery of eight tasks to assess a range of latent cognitive traits reflecting attention, processing speed, verbal declarative memory and semantic fluency (n=919 individuals, 49.9% female). Tsimane cognitive abilities show similar age-related differences as observed in industrialized populations: higher throughout adolescence and only slightly lower in later adulthood for semantic fluency, but substantially lower performance beginning in early adulthood for all other abilities. Schooling is associated with greater cognitive abilities at all ages controlling for sex, but has no attenuating effect on cognitive performance in late adulthood, consistent with models of passive cognitive reserve. We interpret the minimal attenuation of semantic fluency late in life in light of evolutionary theories of post-reproductive lifespan, which emphasize indirect fitness contributions of older adults through the transfer of information, labor and food to descendant kin. PMID:27584668

Information Processing from Infancy to 11 Years: Continuities and Prediction of IQ

PubMed Central

Rose, Susan A.; Feldman, Judith F.; Jankowski, Jeffery J.; Van Rossem, Ronan

2012-01-01

This study provides the first direct evidence of cognitive continuity for multiple specific information processing abilities from infancy and toddlerhood to pre-adolescence, and provides support for the view that infant abilities and form the basis of later childhood abilities. Data from a large sample of children (N = 131) were obtained at five different time points (7, 12, 24, 36 months, and 11 years) for a large battery of tasks representing four cognitive domains (attention, processing speed, memory, and representational competence). Structural equation models of continuity were assessed for each domain, in which it was assumed that infant abilities → toddler abilities → 11-year abilities. Abilities at each age were represented by latent variables, which minimize task-specific variance and measurement error. The model for each domain fit the data. Moreover, abilities from the three age periods predicted global outcome, with infant, toddler, and contemporaneous 11-year measures, respectively, accounting for 12.3%, 18.5%, and 45.2% of the variance in 11-year IQ. These findings strengthen contentions that specific cognitive abilities that can be identified in infancy show long-term continuity and contribute importantly to later cognitive competence. PMID:23162179

Egg incubation effects generate positive correlations between size, speed and learning ability in young lizards.

PubMed

Amiel, Joshua Johnstone; Lindström, Tom; Shine, Richard

2014-03-01

Previous studies have suggested that body size and locomotor performance are targets of Darwinian selection in reptiles. However, much of the variation in these traits may derive from phenotypically plastic responses to incubation temperature, rather than from underlying genetic variation. Intriguingly, incubation temperature may also influence cognitive traits such as learning ability. Therefore, we might expect correlations between a reptile's size, locomotor speed and learning ability either due to selection on all of these traits or due to environmental effects during egg incubation. In the present study, we incubated lizard eggs (Scincidae: Bassiana duperreyi) under 'hot' and 'cold' thermal regimes and then assessed differences in hatchling body size, running speed and learning ability. We measured learning ability using a Y-maze and a food reward. We found high correlations between size, speed and learning ability, using two different metrics to quantify learning (time to solution, and directness of route), and showed that environmental effects (incubation temperature) cause these correlations. If widespread, such correlations challenge any simple interpretation of fitness advantages due to body size or speed within a population; for example, survivors may be larger and faster than nonsurvivors because of differences in learning ability, not because of their size or speed.

Cognitive domains that predict time to diagnosis in prodromal Huntington disease.

PubMed

Harrington, Deborah Lynn; Smith, Megan M; Zhang, Ying; Carlozzi, Noelle E; Paulsen, Jane S

2012-06-01

Prodromal Huntington's disease (prHD) is associated with a myriad of cognitive changes but the domains that best predict time to clinical diagnosis have not been studied. This is a notable gap because some domains may be more sensitive to cognitive decline, which would inform clinical trials. The present study sought to characterise cognitive domains underlying a large test battery and for the first time, evaluate their ability to predict time to diagnosis. Participants included gene negative and gene positive prHD participants who were enrolled in the PREDICT-HD study. The CAG-age product (CAP) score was the measure of an individual's genetic signature. A factor analysis of 18 tests was performed to identify sets of measures or latent factors that elucidated core constructs of tests. Factor scores were then fit to a survival model to evaluate their ability to predict time to diagnosis. Six factors were identified: (1) speed/inhibition, (2) verbal working memory, (3) motor planning/speed, (4) attention-information integration, (5) sensory-perceptual processing and (6) verbal learning/memory. Factor scores were sensitive to worsening of cognitive functioning in prHD, typically more so than performances on individual tests comprising the factors. Only the motor planning/speed and sensory-perceptual processing factors predicted time to diagnosis, after controlling for CAP scores and motor symptoms. Conclusions The results suggest that motor planning/speed and sensory-perceptual processing are important markers of disease prognosis. The findings also have implications for using composite indices of cognition in preventive Huntington's disease trials where they may be more sensitive than individual tests.

Brain Responses to Emotional Images Related to Cognitive Ability in Older Adults

PubMed Central

Foster, Shannon M.; Davis, Hasker P.; Kisley, Michael A.

2013-01-01

Older adults have been shown to exhibit a positivity effect in processing of emotional stimuli, seemingly focusing more on positive than negative information. Whether this reflects purposeful changes or an unintended side-effect of declining cognitive abilities is unclear. For the present study older adults displaying a wide range of cognitive abilities completed measures of attention, visual and verbal memory, executive functioning, and processing speed, as well as a socioemotional measure of time perspective. Regression analyses examined the ability of these variables to predict neural responsivity to select emotional stimuli as measured with the late positive potential (LPP), an event-related brain potential (ERP). Stronger cognitive functioning was associated with higher LPP amplitude in response to negative images (i.e., greater processing). This does not support a voluntary avoidance of negative information processing in older adults for this particular measure of attentional allocation. A model is proposed to reconcile this finding with the extant literature that has demonstrated positivity effects in measures of later, controlled attentional allocation. PMID:23276213

Age-Related Decline in Anticipatory Motor Planning and Its Relation to Cognitive and Motor Skill Proficiency.

PubMed

Stöckel, Tino; Wunsch, Kathrin; Hughes, Charmayne M L

2017-01-01

Anticipatory motor planning abilities mature as children grow older, develop throughout childhood and are likely to be stable till the late sixties. In the seventh decade of life, motor planning performance dramatically declines, with anticipatory motor planning abilities falling to levels of those exhibited by children. At present, the processes enabling successful anticipatory motor planning in general, as do the cognitive processes mediating these age-related changes, remain elusive. Thus, the aim of the present study was (a) to identify cognitive and motor functions that are most affected by normal aging and (b) to elucidate key (cognitive and motor) factors that are critical for successful motor planning performance in young ( n = 40, mean age = 23.1 ± 2.6 years) and older adults ( n = 37, mean age = 73.5 ± 7.1 years). Results indicate that normal aging is associated with a marked decline in all aspects of cognitive and motor functioning tested. However, age-related declines were more apparent for fine motor dexterity, processing speed and cognitive flexibility. Furthermore, up to 64% of the variance in motor planning performance across age groups could be explained by the cognitive functions processing speed, response planning and cognitive flexibility. It can be postulated that anticipatory motor planning abilities are strongly influenced by cognitive control processes, which seem to be key mechanisms to compensate for age-related decline. These findings support the general therapeutic and preventive value of cognitive-motor training programs to reduce adverse effects associated with high age.

Which Working Memory Functions Predict Intelligence?

ERIC Educational Resources Information Center

Oberauer, Klaus; Sub, Heinz-Martin; Wilhelm, Oliver; Wittmann, Werner W.

2008-01-01

Investigates the relationship between three factors of working memory (storage and processing, relational integration, and supervision) and four factors of intelligence (reasoning, speed, memory, and creativity) using structural equation models. Relational integration predicted reasoning ability at least as well as the storage-and-processing…

Dual N-Back Working Memory Training in Healthy Adults: A Randomized Comparison to Processing Speed Training

PubMed Central

Lawlor-Savage, Linette; Goghari, Vina M.

2016-01-01

Enhancing cognitive ability is an attractive concept, particularly for middle-aged adults interested in maintaining cognitive functioning and preventing age-related declines. Computerized working memory training has been investigated as a safe method of cognitive enhancement in younger and older adults, although few studies have considered the potential impact of working memory training on middle-aged adults. This study investigated dual n-back working memory training in healthy adults aged 30–60. Fifty-seven adults completed measures of working memory, processing speed, and fluid intelligence before and after a 5-week web-based dual n-back or active control (processing speed) training program. Results: Repeated measures multivariate analysis of variance failed to identify improvements across the three cognitive composites, working memory, processing speed, and fluid intelligence, after training. Follow-up Bayesian analyses supported null findings for training effects for each individual composite. Findings suggest that dual n-back working memory training may not benefit working memory or fluid intelligence in healthy adults. Further investigation is necessary to clarify if other forms of working memory training may be beneficial, and what factors impact training-related benefits, should they occur, in this population. PMID:27043141

Integrated, nonvolatile, high-speed analog random access memory

NASA Technical Reports Server (NTRS)

Katti, Romney R. (Inventor); Wu, Jiin-Chuan (Inventor); Stadler, Henry L. (Inventor)

1994-01-01

This invention provides an integrated, non-volatile, high-speed random access memory. A magnetically switchable ferromagnetic or ferrimagnetic layer is sandwiched between an electrical conductor which provides the ability to magnetize the magnetically switchable layer and a magneto resistive or Hall effect material which allows sensing the magnetic field which emanates from the magnetization of the magnetically switchable layer. By using this integrated three-layer form, the writing process, which is controlled by the conductor, is separated from the storage medium in the magnetic layer and from the readback process which is controlled by the magnetoresistive layer. A circuit for implementing the memory in CMOS or the like is disclosed.

Useful field of view test.

PubMed

Wood, Joanne M; Owsley, Cynthia

2014-01-01

The useful field of view test was developed to reflect the visual difficulties that older adults experience with everyday tasks. Importantly, the useful field of view test (UFOV) is one of the most extensively researched and promising predictor tests for a range of driving outcomes measures, including driving ability and crash risk as well as other everyday tasks. Currently available commercial versions of the test can be administered using personal computers; these measure the speed of visual processing for rapid detection and localization of targets under conditions of divided visual attention and in the presence and absence of visual clutter. The test is believed to assess higher-order cognitive abilities, but performance also relies on visual sensory function because in order for targets to be attended to, they must be visible. The format of the UFOV has been modified over the years; the original version estimated the spatial extent of useful field of view, while the latest version measures visual processing speed. While deficits in the useful field of view are associated with functional impairments in everyday activities in older adults, there is also emerging evidence from several research groups that improvements in visual processing speed can be achieved through training. These improvements have been shown to reduce crash risk, and can have a positive impact on health and functional well-being, with the potential to increase the mobility and hence the independence of older adults. © 2014 S. Karger AG, Basel

Evaluation of Tests of Processing Speed, Spatial Ability, and Working Memory for use in Military Occupational Classification

DTIC Science & Technology

2013-12-01

61 .62 .01 Operations Specialist 1,676 .74 .73 .72 .74 .02 Dental Technician 516 .63 .61 .62 .64 .02 Personnelman 942 .62 .63 .60 .63 .03...2 obviously apply to a mix of clerical and non-clerical occupations (i.e., Signalman, Radioman, Operations Specialist, and Dental Technician). More...Stachowski, & Dressel, 2011; Russell, Le, & Putka, 2007), Marine Corps ( Carey , 1994), and Navy (Held et al., 2002; Held et al., 2004). 9 Coding Speed

Humans do not have direct access to retinal flow during walking

PubMed Central

Souman, Jan L.; Freeman, Tom C.A.; Eikmeier, Verena; Ernst, Marc O.

2013-01-01

Perceived visual speed has been reported to be reduced during walking. This reduction has been attributed to a partial subtraction of walking speed from visual speed (Durgin & Gigone, 2007; Durgin, Gigone, & Scott, 2005). We tested whether observers still have access to the retinal flow before subtraction takes place. Observers performed a 2IFC visual speed discrimination task while walking on a treadmill. In one condition, walking speed was identical in the two intervals, while in a second condition walking speed differed between intervals. If observers have access to the retinal flow before subtraction, any changes in walking speed across intervals should not affect their ability to discriminate retinal flow speed. Contrary to this “direct-access hypothesis”, we found that observers were worse at discrimination when walking speed differed between intervals. The results therefore suggest that observers do not have access to retinal flow before subtraction. We also found that the amount of subtraction depended on the visual speed presented, suggesting that the interaction between the processing of visual input and of self-motion is more complex than previously proposed. PMID:20884509

Reading accuracy and speed of vowelized and unvowelized scripts among dyslexic readers of Hebrew: the road not taken.

PubMed

Schiff, Rachel; Katzir, Tami; Shoshan, Noa

2013-07-01

The present study examined the effects of orthographic transparency on reading ability of children with dyslexia in two Hebrew scripts. The study explored the reading accuracy and speed of vowelized and unvowelized Hebrew words of fourth-grade children with dyslexia. A comparison was made to typically developing readers of two age groups: a group matched by chronological age and a group of children who are 2 years younger, presumably at the end of the reading acquisition process. An additional purpose was to investigate the role of vowelization in the reading ability of unvowelized script among readers with dyslexia in an attempt to assess whether vowelization plays a mediating role for reading speed of unvowelized scripts. The present study found no significant differences in reading accuracy and speed between vowelized and unvowelized scripts among fourth-grade readers with dyslexia. The reading speed of fourth-graders with dyslexia was similar to typically developing second-graders for both the vowelized and unvowelized words. However, fourth-grade children with dyslexia performed lower than the typically developing second-graders in the reading accuracy of vowelized script. Furthermore, for readers with dyslexia, accuracy in reading both vowelized and unvowelized words mediated the reading speed of unvowelized scripts. These results may be a sign that Hebrew-speaking children with dyslexia have severe difficulties that prevent them from developing strategies for more efficient reading.

Automatic Data Processing Equipment (ADPE) acquisition plan for the medical sciences

NASA Technical Reports Server (NTRS)

1979-01-01

An effective mechanism for meeting the SLSD/MSD data handling/processing requirements for Shuttle is discussed. The ability to meet these requirements depends upon the availability of a general purpose high speed digital computer system. This system is expected to implement those data base management and processing functions required across all SLSD/MSD programs during training, laboratory operations/analysis, simulations, mission operations, and post mission analysis/reporting.

The selective use of functional optical variables in the control of forward speed

NASA Technical Reports Server (NTRS)

Johnson, Walter W.; Awe, Cynthia A.

1994-01-01

Previous work on the perception and control of simulated vehicle speed has examined the contributions of optical flow rate (angular visual speed) and texture, or edge rate (frequency of passing terrain objects or markings) on the perception and control of forward speed. However, these studies have not examined the ability to selectively use edge rate or flow rate. The two studies presented here show that this ability is far greater for pilots than non-pilots, as would be expected since pilots must control vehicular speed over a variety of altitudes where flow rates change independently of forward speed. These studies also show that this ability to selectively use these variables is linked to the visual contextual information about the relative validity (linkage with speed) of the two variables. Subjective judgment data also indicated that awareness of altitude and ground texture density did not mediate ground speed awareness.

Carotid disease at age 73 and cognitive change from age 70 to 76 years: A longitudinal cohort study

PubMed Central

Allerhand, Michael; Eadie, Elizabeth; Thomas, Avril; Corley, Janey; Pattie, Alison; Taylor, Adele; Shenkin, Susan D; Cox, Simon; Gow, Alan; Starr, John M; Deary, Ian J

2016-01-01

Cognitive decline and carotid artery atheroma are common at older ages. In community-dwelling subjects, we assessed cognition at ages 70, 73 and 76 and carotid Doppler ultrasound at age 73, to determine whether carotid stenosis was related to cognitive decline. We used latent growth curve models to examine associations between four carotid measures (internal carotid artery stenosis, velocity, pulsatility and resistivity indices) and four cognitive ability domains (memory, visuospatial function, crystallised intelligence, processing speed) adjusted for cognitive ability at age 11, current age, gender and vascular risk factors. Amongst 866 participants, carotid stenosis (median 12.96%) was not associated with cognitive abilities at age 70 or cognitive decline from age 70 to 76. Increased ICA pulsatility and resistivity indices were associated with slower processing speed (both P < 0.001) and worse visuospatial function (P = 0.036, 0.031, respectively) at age 70, and declining crystallised intelligence from ages 70 to 76 (P = 0.008, 0.006, respectively). The findings suggest that vascular stiffening, rather than carotid luminal narrowing, adversely influences cognitive ageing and provides a potential target for ameliorating age-related cognitive decline. PMID:28155579

Carotid disease at age 73 and cognitive change from age 70 to 76 years: A longitudinal cohort study.

PubMed

Wardlaw, Joanna M; Allerhand, Michael; Eadie, Elizabeth; Thomas, Avril; Corley, Janey; Pattie, Alison; Taylor, Adele; Shenkin, Susan D; Cox, Simon; Gow, Alan; Starr, John M; Deary, Ian J

2017-08-01

Cognitive decline and carotid artery atheroma are common at older ages. In community-dwelling subjects, we assessed cognition at ages 70, 73 and 76 and carotid Doppler ultrasound at age 73, to determine whether carotid stenosis was related to cognitive decline. We used latent growth curve models to examine associations between four carotid measures (internal carotid artery stenosis, velocity, pulsatility and resistivity indices) and four cognitive ability domains (memory, visuospatial function, crystallised intelligence, processing speed) adjusted for cognitive ability at age 11, current age, gender and vascular risk factors. Amongst 866 participants, carotid stenosis (median 12.96%) was not associated with cognitive abilities at age 70 or cognitive decline from age 70 to 76. Increased ICA pulsatility and resistivity indices were associated with slower processing speed (both P < 0.001) and worse visuospatial function ( P = 0.036, 0.031, respectively) at age 70, and declining crystallised intelligence from ages 70 to 76 ( P = 0.008, 0.006, respectively). The findings suggest that vascular stiffening, rather than carotid luminal narrowing, adversely influences cognitive ageing and provides a potential target for ameliorating age-related cognitive decline.

What’s the Story? The Tale of Reading Fluency Told at Speed

PubMed Central

Benjamin, Christopher F. A.; Gaab, Nadine

2012-01-01

Fluent readers process written text rapidly and accurately, and comprehend what they read. Historically, reading fluency has been modeled as the product of discrete skills such as single word decoding. More recent conceptualizations emphasize that fluent reading is the product of competency in, and the coordination of, multiple cognitive sub-skills (a multi-componential view). In this study, we examined how the pattern of activation in core reading regions changes as the ability to read fluently is manipulated through reading speed. We evaluated 13 right-handed adults with a novel fMRI task assessing fluent sentence reading and lower-order letter reading at each participant’s normal fluent reading speed, as well as constrained (slowed) and accelerated reading speeds. Comparing fluent reading conditions with rest revealed regions including bilateral occipito-fusiform, left middle temporal, and inferior frontal gyral clusters across reading speeds. The selectivity of these regions’ responses to fluent sentence reading was shown by comparison with the letter reading task. Region of interest analyses showed that at constrained and accelerated speeds these regions responded significantly more to fluent sentence reading. Critically, as reading speed increased, activation increased in a single reading-related region: occipital/fusiform cortex (left > right). These results demonstrate that while brain regions engaged in reading respond selectively during fluent reading, these regions respond differently as the ability to read fluently is manipulated. Implications for our understanding of reading fluency, reading development, and reading disorders are discussed. PMID:21954000

Knowing a Lot for One's Age: Vocabulary Skill and Not Age Is Associated with Anticipatory Incremental Sentence Interpretation in Children and Adults

ERIC Educational Resources Information Center

Borovsky, Arielle; Elman, Jeffrey L.; Fernald, Anne

2012-01-01

Adults can incrementally combine information from speech with astonishing speed to anticipate future words. Concurrently, a growing body of work suggests that vocabulary ability is crucially related to lexical processing skills in children. However, little is known about this relationship with predictive sentence processing in children or adults.…

Associations between cognitive and gait performance during single- and dual-task walking in people with Parkinson disease.

PubMed

Stegemöller, Elizabeth L; Wilson, Jonathan P; Hazamy, Audrey; Shelley, Mack C; Okun, Michael S; Altmann, Lori J P; Hass, Chris J

2014-06-01

Cognitive impairments in Parkinson disease (PD) manifest as deficits in speed of processing, working memory, and executive function and attention abilities. The gait impairment in PD is well documented to include reduced speed, shortened step lengths, and increased step-to-step variability. However, there is a paucity of research examining the relationship between overground walking and cognitive performance in people with PD. This study sought to examine the relationship between both the mean and variability of gait spatiotemporal parameters and cognitive performance across a broad range of cognitive domains. A cross-sectional design was used. Thirty-five participants with no dementia and diagnosed with idiopathic PD completed a battery of 12 cognitive tests that yielded 3 orthogonal factors: processing speed, working memory, and executive function and attention. Participants completed 10 trials of overground walking (single-task walking) and 5 trials of overground walking while counting backward by 3's (dual-task walking). All gait measures were impaired by the dual task. Cognitive processing speed correlated with stride length and walking speed. Executive function correlated with step width variability. There were no significant associations with working memory. Regression models relating speed of processing to gait spatiotemporal variables revealed that including dual-task costs in the model significantly improved the fit of the model. Participants with PD were tested only in the on-medication state. Different characteristics of gait are related to distinct types of cognitive processing, which may be differentially affected by dual-task walking due to the pathology of PD. © 2014 American Physical Therapy Association.

Associations between cognitive abilities and life satisfaction in the oldest-old. Results from the longitudinal population study Good Aging in Skåne

PubMed Central

Enkvist, Åsa; Ekström, Henrik; Elmståhl, Sölve

2013-01-01

Introduction Studies on the associations between cognitive abilities and life satisfaction (LS) in the oldest-old are few. The aim of this study was to explore whether abilities in six different cognitive domains could predict LS in the oldest-old 3 years later. Methods The study population consisted of 681 individuals aged 78–98 years, drawn from the longitudinal population study “Good Aging in Skåne,” which is part of a national survey (The Swedish National Study on Aging and Care). Scores on 13 cognitive tests were related to scores on Neugartens’ LS index A (LSI-A) 3 years later. The cognitive tests were added into six different cognitive domains. A multiple regression analysis was constructed for each cognitive domain separately, with scores on the LSI-A as the dependent variable. The model was adjusted stepwise for sex, age, education, functional capacity, and depressive mood. Results Significant correlations were found between digit cancellation, word recall, verbal fluency (VF) A, VF animals, VF occupations, and mental rotations at baseline, as well as LSI-A at follow-up. The domains of spatial abilities (B = 0.453, P = 0.014) and processing speed (B = 0.118, P = 0.020) remained significantly associated with LSI-A 3 years later after adjustment. Conclusion The cognitive domains of spatial abilities and processing speed predicted LS 3 years later in the oldest-old. Clinical implications are discussed. PMID:23874091

Retinal microvascular network geometry and cognitive abilities in community-dwelling older people: The Lothian Birth Cohort 1936 study

PubMed Central

McGrory, Sarah; Taylor, Adele M; Kirin, Mirna; Corley, Janie; Pattie, Alison; Cox, Simon R; Dhillon, Baljean; Wardlaw, Joanna M; Doubal, Fergus N; Starr, John M; Trucco, Emanuele; MacGillivray, Thomas J; Deary, Ian J

2017-01-01

Aim To examine the relationship between retinal vascular morphology and cognitive abilities in a narrow-age cohort of community-dwelling older people. Methods Digital retinal images taken at age ∼73 years from 683 participants of the Lothian Birth Cohort 1936 (LBC1936) were analysed with Singapore I Vessel Assessment (SIVA) software. Multiple regression models were applied to determine cross-sectional associations between retinal vascular parameters and general cognitive ability (g), memory, processing speed, visuospatial ability, crystallised cognitive ability and change in IQ from childhood to older age. Results After adjustment for cognitive ability at age 11 years and cardiovascular risk factors, venular length-to-diameter ratio was nominally significantly associated with processing speed (β=−0.116, p=0.01) and g (β=−0.079, p=0.04). Arteriolar length-to-diameter ratio was associated with visuospatial ability (β=0.092, p=0.04). Decreased arteriolar junctional exponent deviation and increased arteriolar branching coefficient values were associated with less relative decline in IQ between childhood and older age (arteriolar junctional exponent deviation: β=−0.101, p=0.02; arteriolar branching coefficient: β=0.089, p=0.04). Data are presented as standardised β coefficients (β) reflecting change in cognitive domain score associated with an increase of 1 SD unit in retinal parameter. None of these nominally significant associations remained significant after correction for multiple statistical testing. Conclusions Retinal parameters contributed <1% of the variance in the majority of associations observed. Whereas retinal analysis may have potential for early detection of some types of age-related cognitive decline and dementia, our results present little evidence that retinal vascular features are associated with non-pathological cognitive ageing. PMID:28400371

Psychological and Physiological Processes in Figure-Tracing Abilities Measured Using a Tablet Computer: A Study with 7 and 9 Years Old Children

PubMed Central

Giammarco, Enrico; Di Sano, Sergio; Aureli, Tiziana; Cerratti, Paola; Fanò-Illic, Giorgio; Pietrangelo, Tiziana

2016-01-01

The present study investigated the use of a tablet computer to assess figure-tracing skills and their relationships with psychological (visual–perceptual processes, cognitive processes, handwriting skills) and physiological (body mass index, isometric strength of arms) parameters with school-children of second (7–8-year-olds) and fourth (9–10-year-olds) grades. We were also interested in gender differences. The task required tracing of geometric figures on a template, shown on a tablet screen in light gray, for the segments that make up the target figure, one at a time. This figure-tracing tablet test allows acquisition and automated analysis of four parameters: number of strokes (pen lift) for each segment; oscillations of lines drawn with respect to reference lines; pressure of pen on tablet; and average speed of tracing. The results show a trade-off between speed and quality for the tablet parameters, with higher speed associated with more oscillations with respect to the reference lines, and lower number of strokes for each segment, in both male and female children. The involvement of visual–motor integration on the ability to reduce the oscillations in this tablet test was only seen for the male children, while both the male and female children showed a relationship between oscillations and more general/abstract visual–spatial processes. These data confirm the role of visual–motor processes in this figure-tracing tablet test only for male children, while more general visual–spatial processes influence the performance in the tablet test for both sexes. We conclude that the test proposed is useful to screen for grapho-motor difficulties. PMID:27803678

Adaptive functioning following pediatric traumatic brain injury: Relationship to executive function and processing speed.

PubMed

Shultz, Emily L; Hoskinson, Kristen R; Keim, Madelaine C; Dennis, Maureen; Taylor, H Gerry; Bigler, Erin D; Rubin, Kenneth H; Vannatta, Kathryn; Gerhardt, Cynthia A; Stancin, Terry; Yeates, Keith Owen

2016-10-01

Pediatric traumatic brain injury (TBI) may affect children's ability to perform everyday tasks (i.e., adaptive functioning). Guided by the American Association for Intellectual and Developmental Disabilities (AAIDD) model, we explored the association between TBI and adaptive functioning at increasing levels of specificity (global, AAIDD domains, and subscales). We also examined the contributions of executive function and processing speed as mediators of TBI's effects on adaptive functioning. Children (ages 8-13) with severe TBI (STBI; n = 19), mild-moderate TBI (MTBI; n = 50), or orthopedic injury (OI; n = 60) completed measures of executive function (TEA-Ch) and processing speed (WISC-IV) an average of 2.7 years postinjury (SD = 1.2; range: 1-5.3). Parents rated children's adaptive functioning (ABAS-II, BASC-2, CASP). STBI had lower global adaptive functioning (η2 = .04-.08) than the MTBI and OI groups, which typically did not differ. Deficits in the STBI group were particularly evident in the social domain, with specific deficits in social participation, leisure, and social adjustment (η2 = .06-.09). Jointly, executive function and processing speed were mediators of STBI's effects on global adaptive functioning and in conceptual and social domains. In the STBI group, executive function mediated social functioning, and processing speed mediated social participation. Children with STBI experience deficits in adaptive functioning, particularly in social adjustment, with less pronounced deficits in conceptual and practical skills. Executive function and processing speed may mediate the effects of STBI on adaptive functioning. Targeting adaptive functioning and associated cognitive deficits for intervention may enhance quality of life for pediatric TBI survivors. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Adaptive functioning following pediatric traumatic brain injury: Relationship to executive function and processing speed

PubMed Central

Shultz, Emily; Robinson, Kristen E.; Keim, Madelaine; Dennis, Maureen; Taylor, H. Gerry; Bigler, Erin D.; Rubin, Kenneth H.; Vannatta, Kathryn; Gerhardt, Cynthia A.; Stancin, Terry; Yeates, Keith Owen

2016-01-01

Objective Pediatric traumatic brain injury (TBI) may affect children’s ability to perform everyday tasks (i.e., adaptive functioning). Guided by the American Association for Intellectual and Developmental Disabilities (AAIDD) model, we explored the association between TBI and adaptive functioning at increasing levels of specificity (global, AAIDD domains, and subscales). We also examined the contributions of executive function and processing speed as mediators of TBI’s effects on adaptive functioning. Method Children (ages 8–13) with severe TBI (STBI; n=19), mild-moderate TBI (MTBI; n=50), or orthopedic injury (OI; n=60) completed measures of executive function (TEA-Ch) and processing speed (WISC-IV) an average of 2.7 years post-injury (SD = 1.2; range: 1–5.3). Parents rated children’s adaptive functioning (ABAS-II, BASC-2, CASP). Results STBI had lower global adaptive functioning (η2 = .04–.08) than the MTBI and OI groups, which typically did not differ. Deficits in the STBI group were particularly evident in the social domain, with specific deficits in social participation, leisure, and social adjustment (η2 = .06–.09). Jointly, executive function and processing speed were mediators of STBI’s effects on global adaptive functioning and in conceptual and social domains. In the STBI group, executive function mediated social functioning, and processing speed mediated social participation. Conclusions Children with STBI experience deficits in adaptive functioning, particularly in social adjustment, with less pronounced deficits in conceptual and practical skills. Executive function and processing speed may mediate the effects of STBI on adaptive functioning. Targeting adaptive functioning and associated cognitive deficits for intervention may enhance quality of life for pediatric TBI survivors. PMID:27182708

Level of Cognitive Performance as a Correlate and Predictor of Health Behaviors that Protect against Cognitive Decline in Late Life: The Path through Life Study

ERIC Educational Resources Information Center

Anstey, Kaarin J.; Low, Lee-Fay; Christensen, Helen; Sachdev, Perminder

2009-01-01

There is a lack of information on how cognitive ability relates to both health behaviors and change in health behaviors over time. This study examined verbal ability and processing speed as predictors of health behaviors in the PATH Through Life Study that includes cohorts aged in their 20s, 40s and 60s. Higher cognitive scores were associated…

Why Does Rapid Naming Predict Chinese Word Reading?

ERIC Educational Resources Information Center

Shum, Kathy Kar-man; Au, Terry Kit-fong

2017-01-01

Rapid automatized naming (RAN) robustly predicts early reading abilities across languages, but its underlying mechanism remains unclear. This study found that RAN associated significantly with processing speed but not with phonological awareness or orthographic knowledge in 89 Hong Kong Chinese second-graders. RAN overlaps more with processing…

Relating 7-Month-Olds Visuo-Spatial Working Memory to Other Basic Mental Skills Assessed with Two Different Versions of the Habituation-Dishabituation Paradigm

ERIC Educational Resources Information Center

Ropeter, Anna; Pauen, Sabina

2013-01-01

This study examines the relationship between various basic mental processing abilities in infancy. Two groups of 7-month-olds received the same delayed-response task to assess visuo-spatial working memory, but two different habituation-dishabituation tasks to assess processing speed and recognition memory. The single-stimulus group ("N"…

Age-Related Decline in Anticipatory Motor Planning and Its Relation to Cognitive and Motor Skill Proficiency

PubMed Central

Stöckel, Tino; Wunsch, Kathrin; Hughes, Charmayne M. L.

2017-01-01

Anticipatory motor planning abilities mature as children grow older, develop throughout childhood and are likely to be stable till the late sixties. In the seventh decade of life, motor planning performance dramatically declines, with anticipatory motor planning abilities falling to levels of those exhibited by children. At present, the processes enabling successful anticipatory motor planning in general, as do the cognitive processes mediating these age-related changes, remain elusive. Thus, the aim of the present study was (a) to identify cognitive and motor functions that are most affected by normal aging and (b) to elucidate key (cognitive and motor) factors that are critical for successful motor planning performance in young (n = 40, mean age = 23.1 ± 2.6 years) and older adults (n = 37, mean age = 73.5 ± 7.1 years). Results indicate that normal aging is associated with a marked decline in all aspects of cognitive and motor functioning tested. However, age-related declines were more apparent for fine motor dexterity, processing speed and cognitive flexibility. Furthermore, up to 64% of the variance in motor planning performance across age groups could be explained by the cognitive functions processing speed, response planning and cognitive flexibility. It can be postulated that anticipatory motor planning abilities are strongly influenced by cognitive control processes, which seem to be key mechanisms to compensate for age-related decline. These findings support the general therapeutic and preventive value of cognitive-motor training programs to reduce adverse effects associated with high age. PMID:28928653

Brain metabolite levels and language abilities in preschool children.

PubMed

Lebel, Catherine; MacMaster, Frank P; Dewey, Deborah

2016-10-01

Language acquisition occurs rapidly during early childhood and lays the foundation for future reading success. However, little is known about the brain-language relationships in young children. The goal of this study was to investigate relationships between brain metabolites and prereading language abilities in healthy preschool-aged children. Participants were 67 healthy children aged 3.0-5.4 years scanned on a 3T GE MR750w MRI scanner using short echo proton spectroscopy with a voxel placed in the anterior cingulate gyrus ( n  = 56) and/or near the left angular gyrus ( n  = 45). Children completed the NEPSY-II Phonological Processing and Speeded Naming subtests at the same time as their MRI scan. We calculated glutamate, glutamine, creatine/phosphocreatine, choline, inositol, and NAA concentrations, and correlated these with language skills. In the anterior cingulate, Phonological Processing Scaled Scores were significantly correlated with glutamate, creatine, and inositol concentrations. In the left angular gyrus, Speeded Naming Combined Scaled Scores showed trend correlations with choline and glutamine concentrations. For the first time, we demonstrate relationships between brain metabolites and prereading language abilities in young children. Our results show relationships between language and inositol and glutamate that may reflect glial differences underlying language function, and a relationship of language with creatine. The trend between Speeded Naming and choline is consistent with previous research in older children and adults; however, larger sample sizes are needed to confirm whether this relationship is indeed significant in young children. These findings help understand the brain basis of language, and may ultimately lead to earlier and more effective interventions for reading disabilities.

Predictors of Long-Term Victimization After Early Pediatric Traumatic Brain Injury.

PubMed

Hung, Anna H; Cassedy, Amy; Schultz, Hanna M; Yeates, Keith Owen; Taylor, Hudson Gerry; Stancin, Terry; Walz, Nicolay Chertkoff; Wade, Shari L

2017-01-01

Pediatric traumatic brain injuries (TBIs) adversely affect long-term functional and social outcomes. Limited research suggests children with TBI are more likely to be victimized by peers than noninjured children. Deficits in social information processing (SIP), cognitive ability, and executive functioning (EF) may contribute to increased victimization risk. This study examined rates of peer victimization/bullying in children with early TBI compared with children with orthopedic injuries (OIs) and the role of processing speed, executive function (EF), and SIP as mediators of the association of TBI and peer victimization. Children ages 10 to 14 years who sustained a complicated mild/moderate or severe TBI (N = 58) or OI (N = 72) during early childhood (ages 3-7 yr) and their parents participated in a longitudinal prospective follow-up 6.8 years postinjury. SIP, EF and processing speed, and peer victimization were assessed. Parents of children with severe TBI reported greater rates of peer victimization than parents of children with OIs. Children with severe TBI demonstrated greater EF deficits than children with complicated mild/moderate TBI or OI and poorer processing speed than children with OI. No significant indirect relationships were found between groups and any outcome variables to indicate mediation. Based on parent report, children with severe TBI have higher risk of peer victimization than those with less severe injuries. In addition, children with severe TBI have more impaired EF and cognitive ability than counterparts with less severe TBI. Further research is needed to explore predictors of long-term victimization after early TBI to create interventions aimed at providing social, emotional, and behavioral skill building for victimized youth.

Memory Skills of Deaf Learners: Implications and Applications

ERIC Educational Resources Information Center

Hamilton, Harley

2011-01-01

The author reviews research on working memory and short-term memory abilities of deaf individuals, delineating strengths and weaknesses. Among the areas of weakness that are reviewed are sequential recall, processing speed, attention, and memory load. Areas of strengths include free recall, visuospatial recall, imagery, and dual encoding.…

Memory Skills of Deaf Learners: Implications and Applications

ERIC Educational Resources Information Center

Hamilton, Harley

2011-01-01

This paper will review research on working memory and short-term memory abilities of deaf individuals delineating strengths and weaknesses. The areas of memory reviewed include weaknesses such as sequential recall, processing speed, attention, and memory load. Strengths include free recall, visuospatial recall, imagery and dual encoding.…

Human Intelligence: An Introduction to Advances in Theory and Research.

ERIC Educational Resources Information Center

Lohman, David F.

1989-01-01

Recent advances in three research traditions are summarized: trait theories of intelligence, information-processing theories of intelligence, and general theories of thinking. Work on fluid and crystallized abilities by J. Horn and R. Snow, mental speed, spatial visualization, cognitive psychology, artificial intelligence, and the construct of…

Infant Attention and Early Childhood Executive Function

ERIC Educational Resources Information Center

Cuevas, Kimberly; Bell, Martha Ann

2014-01-01

Individual differences in infant attention are theorized to reflect the speed of information processing and are related to later cognitive abilities (i.e., memory, language, and intelligence). This study provides the first systematic longitudinal analysis of infant attention and early childhood executive function (EF; e.g., working memory,…

Exploring Expressive Vocabulary Variability in Two-Year-Olds: The Role of Working Memory.

PubMed

Newbury, Jayne; Klee, Thomas; Stokes, Stephanie F; Moran, Catherine

2015-12-01

This study explored whether measures of working memory ability contribute to the wide variation in 2-year-olds' expressive vocabulary skills. Seventy-nine children (aged 24-30 months) were assessed by using standardized tests of vocabulary and visual cognition, a processing speed measure, and behavioral measures of verbal working memory and phonological short-term memory. Strong correlations were observed between phonological short-term memory, verbal working memory, and expressive vocabulary. Speed of spoken word recognition showed a moderate significant correlation with expressive vocabulary. In a multivariate regression model for expressive vocabulary, the most powerful predictor was a measure of phonological short-term memory (accounting for 66% unique variance), followed by verbal working memory (6%), sex (2%), and age (1%). Processing speed did not add significant unique variance. These findings confirm previous research positing a strong role for phonological short-term memory in early expressive vocabulary acquisition. They also extend previous research in two ways. First, a unique association between verbal working memory and expressive vocabulary in 2-year-olds was observed. Second, processing speed was not a unique predictor of variance in expressive vocabulary when included alongside measures of working memory.

Quantitative multi-modal MRI of the Hippocampus and cognitive ability in community-dwelling older subjects.

PubMed

Aribisala, Benjamin S; Royle, Natalie A; Maniega, Susana Muñoz; Valdés Hernández, Maria C; Murray, Catherine; Penke, Lars; Gow, Alan; Starr, John M; Bastin, Mark E; Deary, Ian J; Wardlaw, Joanna M

2014-04-01

Hippocampal structural integrity is commonly quantified using volumetric measurements derived from brain magnetic resonance imaging (MRI). Previously reported associations with cognitive decline have not been consistent. We investigate hippocampal integrity using quantitative MRI techniques and its association with cognitive abilities in older age. Participants from the Lothian Birth Cohort 1936 underwent brain MRI at mean age 73 years. Longitudinal relaxation time (T1), magnetization transfer ratio (MTR), fractional anisotropy (FA) and mean diffusivity (MD) were measured in the hippocampus. General factors of fluid-type intelligence (g), cognitive processing speed (speed) and memory were obtained at age 73 years, as well as childhood IQ test results at age 11 years. Amongst 565 older adults, multivariate linear regression showed that, after correcting for ICV, gender and age 11 IQ, larger left hippocampal volume was significantly associated with better memory ability (β = .11, p = .003), but not with speed or g. Using quantitative MRI and after correcting for multiple testing, higher T1 and MD were significantly associated with lower scores of g (β range = -.11 to -.14, p < .001), speed (β range = -.15 to -.20, p < .001) and memory (β range = -.10 to -.12, p < .001). Higher MTR and FA in the hippocampus were also significantly associated with higher scores of g (β range = .17 to .18, p < .0001) and speed (β range = .10 to .15, p < .0001), but not memory. Quantitative multi-modal MRI assessments were more sensitive at detecting cognition-hippocampal integrity associations than volumetric measurements, resulting in stronger associations between MRI biomarkers and age-related cognition changes. Copyright © 2014. Published by Elsevier Ltd.

High-speed event detector for embedded nanopore bio-systems.

PubMed

Huang, Yiyun; Magierowski, Sebastian; Ghafar-Zadeh, Ebrahim; Wang, Chengjie

2015-08-01

Biological measurements of microscopic phenomena often deal with discrete-event signals. The ability to automatically carry out such measurements at high-speed in a miniature embedded system is desirable but compromised by high-frequency noise along with practical constraints on filter quality and sampler resolution. This paper presents a real-time event-detection method in the context of nanopore sensing that helps to mitigate these drawbacks and allows accurate signal processing in an embedded system. Simulations show at least a 10× improvement over existing on-line detection methods.

The STEP model: Characterizing simultaneous time effects on practice for flight simulator performance among middle-aged and older pilots

PubMed Central

Kennedy, Quinn; Taylor, Joy; Noda, Art; Yesavage, Jerome; Lazzeroni, Laura C.

2015-01-01

Understanding the possible effects of the number of practice sessions (practice) and time between practice sessions (interval) among middle-aged and older adults in real world tasks has important implications for skill maintenance. Prior training and cognitive ability may impact practice and interval effects on real world tasks. In this study, we took advantage of existing practice data from five simulated flights among 263 middle-aged and older pilots with varying levels of flight expertise (defined by FAA proficiency ratings). We developed a new STEP (Simultaneous Time Effects on Practice) model to: (1) model the simultaneous effects of practice and interval on performance of the five flights, and (2) examine the effects of selected covariates (age, flight expertise, and three composite measures of cognitive ability). The STEP model demonstrated consistent positive practice effects, negative interval effects, and predicted covariate effects. Age negatively moderated the beneficial effects of practice. Additionally, cognitive processing speed and intra-individual variability (IIV) in processing speed moderated the benefits of practice and/or the negative influence of interval for particular flight performance measures. Expertise did not interact with either practice or interval. Results indicate that practice and interval effects occur in simulated flight tasks. However, processing speed and IIV may influence these effects, even among high functioning adults. Results have implications for the design and assessment of training interventions targeted at middle-aged and older adults for complex real world tasks. PMID:26280383

Evaluation of Tests of Perceptual Speed/Accuracy and Spatial Ability for Use in Military Occupational Classification

DTIC Science & Technology

2014-08-22

uncomplicated and inci- dental to the ability being measured. Process- based measures like CS that do not rely on learned content have contributed to military...operations specialist, and dental technician) ratings. These ratings are clearly different from mechanical ratings where AO is, on the face of it, more...performance criteria in studies conducted by the Army (Anderson et al., 2011; Russell, Le, & Putka, 2007), Marine Corps ( Carey , 1994), and Navy (Held, Fedak

The Relationship between a Linear Combination of Intelligence, Musical Background, Rhythm Ability and Tapping Ability to Typewriting Speed and Accuracy.

ERIC Educational Resources Information Center

Fante, Cheryl H.

This study was conducted in an attempt to identify any predictor or combination of predictors of a beginning typewriting student's success. Variables of intelligence, rhythmic ability, musical background, and tapping ability were combined to study their relationship to typewriting speed and accuracy. A sample of 109 high school students was…

The relationship between change in cognition and change in functional ability in schizophrenia during cognitive and psychosocial rehabilitation.

PubMed

Rispaud, Samuel G; Rose, Jennifer; Kurtz, Matthew M

2016-10-30

While a wealth of studies have evaluated cross-sectional links between cognition and functioning in schizophrenia, few have investigated the relationship between change in cognition and change in functioning in the context of treatment trials targeted at cognition. Identifying cognitive skills that, when improved, predict improvement in functioning will guide the development of more targeted rehabilitation for this population. The present study identifies the relationship between change in specific cognitive skills and change in functional ability during one year of cognitive rehabilitation. Ninety-six individuals with schizophrenia were assessed with a battery of cognitive measures and a measure of performance-based functioning before and after cognitive training consisting of either drill-and-practice cognitive remediation or computer skills training. Results revealed that while working and episodic memory, problem-solving, and processing speed skills all improved during the trial, only improved working memory and processing speed skills predicted improvement in functional ability. Secondary analyses revealed these relationships were driven by individuals who showed a moderate level (SD≥0.5) of cognitive improvement during the trial. These findings suggest that while a variety of cognitive skills may improve during training targeted at cognition, only improvements in a subset of cognitive functions may translate into functional gains. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Initial Cognitive Performance Predicts Longitudinal Aviator Performance

PubMed Central

Jo, Booil; Adamson, Maheen M.; Kennedy, Quinn; Noda, Art; Hernandez, Beatriz; Zeitzer, Jamie M.; Friedman, Leah F.; Fairchild, Kaci; Scanlon, Blake K.; Murphy, Greer M.; Taylor, Joy L.

2011-01-01

Objectives. The goal of the study was to improve prediction of longitudinal flight simulator performance by studying cognitive factors that may moderate the influence of chronological age. Method. We examined age-related change in aviation performance in aircraft pilots in relation to baseline cognitive ability measures and aviation expertise. Participants were aircraft pilots (N = 276) aged 40–77.9. Flight simulator performance and cognition were tested yearly; there were an average of 4.3 (± 2.7; range 1–13) data points per participant. Each participant was classified into one of the three levels of aviation expertise based on Federal Aviation Administration pilot proficiency ratings: least, moderate, or high expertise. Results. Addition of measures of cognitive processing speed and executive function to a model of age-related change in aviation performance significantly improved the model. Processing speed and executive function performance interacted such that the slowest rate of decline in flight simulator performance was found in aviators with the highest scores on tests of these abilities. Expertise was beneficial to pilots across the age range studied; however, expertise did not show evidence of reducing the effect of age. Discussion. These data suggest that longitudinal performance on an important real-world activity can be predicted by initial assessment of relevant cognitive abilities. PMID:21586627

Nutritional status and cognitive function in community-living rural Bangladeshi older adults: data from the poverty and health in ageing project.

PubMed

Ferdous, Tamanna; Cederholm, Tommy; Kabir, Zarina Nahar; Hamadani, Jena Derakhshani; Wahlin, Ake

2010-05-01

To investigate the association between nutritional status and general and specific (fluid and crystallized) cognitive functioning in a group of older people living in a rural area in Bangladesh. Cross-sectional study. Matlab, Bangladesh. Four hundred fifty-seven randomly selected persons aged 60 and older (mean age 69.5 +/- 6.8), 55% female. Nutritional status was evaluated using a modified form of the Mini Nutritional Assessment (MNA). General cognitive function was assessed using the Bangla Adaptation of the Mini-Mental State Examination, and a word synonym test was used to test semantic memory function (a crystallized ability). To assess cognitive processing speed (a fluid ability), "cross balls" and "complete boxes" tests (scores/time unit) were used. Clinical diagnoses were registered. Structured questionnaires were used to assess demographic and socioeconomic status of the participants. Twenty-six percent of the participants were undernourished, and 62% were at risk of malnutrition according to the MNA. The MNA scores were significantly lower in women than in men (P=.01). Women performed worse than men in all three cognitive tasks (P<.001). Poorer cognitive performance was independently associated with older age, female sex, illiteracy, visual impairment, severity of disease, and depressive symptoms. There were significant associations between better nutritional status and better cognitive performance tests of general ability and processing speed, whereas semantic memory appeared to be less affected. The association between nutritional status and cognitive function involves general and specific cognitive abilities, with fluid ability seeming to be affected but crystalized functions being relatively spared.

Virtual reality in the assessment of selected cognitive function after brain injury.

PubMed

Zhang, L; Abreu, B C; Masel, B; Scheibel, R S; Christiansen, C H; Huddleston, N; Ottenbacher, K J

2001-08-01

To assess selected cognitive functions of persons with traumatic brain injury using a computer-simulated virtual reality environment. A computer-simulated virtual kitchen was used to assess the ability of 30 patients with brain injury and 30 volunteers without brain injury to process and sequence information. The overall assessment score was based on the number of correct responses and the time needed to complete daily living tasks. Identical daily living tasks were tested and scored in participants with and without brain injury. Each subject was evaluated twice within 7 to 10 days. A total of 30 tasks were categorized as follows: information processing, problem solving, logical sequencing, and speed of responding. Persons with brain injuries consistently demonstrated a significant decrease in the ability to process information (P = 0.04-0.01), identify logical sequencing (P = 0.04-0.01), and complete the overall assessment (P < 0.01), compared with volunteers without brain injury. The time needed to process tasks, representing speed of cognitive responding, was also significantly different between the two groups (P < 0.01). A computer-generated virtual reality environment represents a reproducible tool to assess selected cognitive functions and can be used as a supplement to traditional rehabilitation assessment in persons with acquired brain injury.

New Enhanced Artificial Bee Colony (JA-ABC5) Algorithm with Application for Reactive Power Optimization

PubMed Central

2015-01-01

The standard artificial bee colony (ABC) algorithm involves exploration and exploitation processes which need to be balanced for enhanced performance. This paper proposes a new modified ABC algorithm named JA-ABC5 to enhance convergence speed and improve the ability to reach the global optimum by balancing exploration and exploitation processes. New stages have been proposed at the earlier stages of the algorithm to increase the exploitation process. Besides that, modified mutation equations have also been introduced in the employed and onlooker-bees phases to balance the two processes. The performance of JA-ABC5 has been analyzed on 27 commonly used benchmark functions and tested to optimize the reactive power optimization problem. The performance results have clearly shown that the newly proposed algorithm has outperformed other compared algorithms in terms of convergence speed and global optimum achievement. PMID:25879054

New enhanced artificial bee colony (JA-ABC5) algorithm with application for reactive power optimization.

PubMed

Sulaiman, Noorazliza; Mohamad-Saleh, Junita; Abro, Abdul Ghani

2015-01-01

The standard artificial bee colony (ABC) algorithm involves exploration and exploitation processes which need to be balanced for enhanced performance. This paper proposes a new modified ABC algorithm named JA-ABC5 to enhance convergence speed and improve the ability to reach the global optimum by balancing exploration and exploitation processes. New stages have been proposed at the earlier stages of the algorithm to increase the exploitation process. Besides that, modified mutation equations have also been introduced in the employed and onlooker-bees phases to balance the two processes. The performance of JA-ABC5 has been analyzed on 27 commonly used benchmark functions and tested to optimize the reactive power optimization problem. The performance results have clearly shown that the newly proposed algorithm has outperformed other compared algorithms in terms of convergence speed and global optimum achievement.

The Value of Response Times in Item Response Modeling

ERIC Educational Resources Information Center

Molenaar, Dylan

2015-01-01

A new and very interesting approach to the analysis of responses and response times is proposed by Goldhammer (this issue). In his approach, differences in the speed-ability compromise within respondents are considered to confound the differences in ability between respondents. These confounding effects of speed on the inferences about ability can…

Pathways from Prematurity and Infant Abilities to Later Cognition

ERIC Educational Resources Information Center

Rose, Susan A.; Feldman, Judith F.; Jankowski, Jeffery J.; Van Rossem, Ronan

2005-01-01

This study examined the relation of information processing in 7-month-old preterms ([less than] 1750g at birth) and full-terms to Bayley Mental Development Indexes (MDIs) at 2 and 3 years. The infant measures were drawn from four cognitive domains: attention, speed, memory, and representational competence. Structural equation modeling showed that…

Pragmatic Abilities in Adults with and without Dyslexia: A Pilot Study

ERIC Educational Resources Information Center

Griffiths, Catherine C. B.

2007-01-01

This study examines well-compensated adults with dyslexia to see if they experience more problems with pragmatic awareness than the normal population. Social interaction requires an individual to process language at speed by using working memory efficiently, in order to understand the intended, rather than literal, meaning between speaker and…

Cognitive Reserve and Social Capital Accrued in Early and Midlife Moderate the Relation of Psychological Stress to Cognitive Performance in Old Age.

PubMed

Ihle, Andreas; Oris, Michel; Sauter, Julia; Rimmele, Ulrike; Kliegel, Matthias

2018-06-05

The present study set out to investigate the relation of psychological stress to cognitive performance and its interplay with key life course markers of cognitive reserve and social capital in a large sample of older adults. We assessed cognitive performance (verbal abilities and processing speed) and psychological stress in 2,812 older adults. The Participants reported information on education, occupation, leisure activities, family, and close friends. Greater psychological stress was significantly related to lower performance in verbal abilities and processing speed. Moderation analyses suggested that the relations of psychological stress to cognitive performance were reduced in individuals with higher education, a higher cognitive level of the first profession practiced after education, a larger number of midlife leisure activities, a larger number of significant family members, and a larger number of close friends. Cognitive reserve and social capital accrued in early and midlife may reduce the detrimental influences of psychological stress on cognitive functioning in old age. © 2018 S. Karger AG, Basel.

Potential effect of skull thickening on the associations between cognition and brain atrophy in ageing.

PubMed

Aribisala, Benjamin Segun; Royle, Natalie A; Valdés Hernández, Maria C; Murray, Catherine; Penke, Lars; Gow, Alan; Maniega, Susana Muñoz; Starr, John M; Bastin, Mark; Deary, Ian; Wardlaw, Joanna

2014-09-01

intracranial volume (ICV) is commonly used as a marker of premorbid brain size in neuroimaging studies as it is thought to remain fixed throughout adulthood. However, inner skull table thickening would encroach on ICV and could mask actual brain atrophy. we investigated the effect that thickening might have on the associations between brain atrophy and cognition. the sample comprised 57 non-demented older adults who underwent structural brain MRI at mean age 72.7 ± 0.7 years and were assessed on cognitive ability at mean age 11 and 73 years. Principal component analysis was used to derive factors of general cognitive ability (g), information processing speed and memory from the recorded cognitive ability data. The total brain tissue volume and ICV with (estimated original ICV) and without (current ICV) adjusting for the effects of inner table skull thickening were measured. General linear modelling was used to test for associations. all cognitive ability variables were significantly (P < 0.01) associated with percentage total brain volume in ICV measured without adjusting for skull thickening (g: η(2) = 0.177, speed: η(2) = 0.264 and memory: η(2) = 0.132). After accounting for skull thickening, only speed was significantly associated with percentage total brain volume in ICV (η(2) = 0.085, P = 0.034), not g or memory. not accounting for skull thickening when computing ICV can distort the association between brain atrophy and cognitive ability in old age. Larger samples are required to determine the true effect. © The Author 2014. Published by Oxford University Press on behalf of the British Geriatrics Society. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Control of Walking Speed in Children With Cerebral Palsy.

PubMed

Davids, Jon R; Cung, Nina Q; Chen, Suzy; Sison-Williamson, Mitell; Bagley, Anita M

2017-03-21

Children's ability to control the speed of gait is important for a wide range of activities. It is thought that the ability to increase the speed of gait for children with cerebral palsy (CP) is common. This study considered 3 hypotheses: (1) most ambulatory children with CP can increase gait speed, (2) the characteristics of free (self-selected) and fast walking are related to motor impairment level, and (3) the strategies used to increase gait speed are distinct among these levels. A retrospective review of time-distance parameters (TDPs) for 212 subjects with CP and 34 typically developing subjects walking at free and fast speeds was performed. Only children who could increase their gait speed above the minimal clinically important difference were defined as having a fast walk. Analysis of variance was used to compare TDPs of children with CP, among Gross Motor Function Classification System (GMFCS) levels, and children in typically developing group. Eight-five percent of the CP group (GMFCS I, II, III; 96%, 99%, and 34%, respectively) could increase gait speed on demand. At free speed, children at GMFCS I and II were significantly faster than children at GMFCS level III. At free speed, children at GMFCS I and II had significantly greater stride length than those at GMFCS levels III. At free speed, children at GMFCS level III had significantly lower cadence than those at GMFCS I and II. There were no significant differences in cadence among GMFCS levels at fast speeds. There were no significant differences among GMFCS levels for percent change in any TDP between free and fast walking. Almost all children with CP at GMFCS levels I and II can control the speed of gait, however, only one-third at GMFCS III level have this ability. This study suggests that children at GMFCS III level can be divided into 2 groups based on their ability to control gait speed; however, the prognostic significance of such categorization remains to be determined. Diagnostic level II.

Using implicit association tests in age-heterogeneous samples: The importance of cognitive abilities and quad model processes.

PubMed

Wrzus, Cornelia; Egloff, Boris; Riediger, Michaela

2017-08-01

Implicit association tests (IATs) are increasingly used to indirectly assess people's traits, attitudes, or other characteristics. In addition to measuring traits or attitudes, IAT scores also reflect differences in cognitive abilities because scores are based on reaction times (RTs) and errors. As cognitive abilities change with age, questions arise concerning the usage and interpretation of IATs for people of different age. To address these questions, the current study examined how cognitive abilities and cognitive processes (i.e., quad model parameters) contribute to IAT results in a large age-heterogeneous sample. Participants (N = 549; 51% female) in an age-stratified sample (range = 12-88 years) completed different IATs and 2 tasks to assess cognitive processing speed and verbal ability. From the IAT data, D2-scores were computed based on RTs, and quad process parameters (activation of associations, overcoming bias, detection, guessing) were estimated from individual error rates. Substantial IAT scores and quad processes except guessing varied with age. Quad processes AC and D predicted D2-scores of the content-specific IAT. Importantly, the effects of cognitive abilities and quad processes on IAT scores were not significantly moderated by participants' age. These findings suggest that IATs seem suitable for age-heterogeneous studies from adolescence to old age when IATs are constructed and analyzed appropriately, for example with D-scores and process parameters. We offer further insight into how D-scoring controls for method effects in IATs and what IAT scores capture in addition to implicit representations of characteristics. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

INDIVIDUAL DIFFERENCES IN TASK-SPECIFIC PAIRED ASSOCIATES LEARNING IN OLDER ADULTS: THE ROLE OF PROCESSING SPEED AND WORKING MEMORY

PubMed Central

Kurtz, Tanja; Mogle, Jacqueline; Sliwinski, Martin J.; Hofer, Scott M.

2013-01-01

Background The role of processing speed and working memory was investigated in terms of individual differences in task-specific paired associates learning in a sample of older adults. Task-specific learning, as distinct from content-oriented item-specific learning, refers to gains in performance due to repeated practice on a learning task in which the to-be-learned material changes over trials. Methods Learning trajectories were modeled within an intensive repeated-measures design based on participants obtained from an opt-in internet-based sampling service (Mage = 65.3, SD = 4.81). Participants completed an eight-item paired associates task daily over a seven-day period. Results Results indicated that a three-parameter hyperbolic model (i.e., initial level, learning rate, and asymptotic performance) best described learning trajectory. After controlling for age-related effects, both higher working memory and higher processing speed had a positive effect on all three learning parameters. Conclusion These results emphasize the role of cognitive abilities for individual differences in task-specific learning of older adults. PMID:24151913

Coupled changes in brain white matter microstructure and fluid intelligence in later life.

PubMed

Ritchie, Stuart J; Bastin, Mark E; Tucker-Drob, Elliot M; Maniega, Susana Muñoz; Engelhardt, Laura E; Cox, Simon R; Royle, Natalie A; Gow, Alan J; Corley, Janie; Pattie, Alison; Taylor, Adele M; Valdés Hernández, Maria Del C; Starr, John M; Wardlaw, Joanna M; Deary, Ian J

2015-06-03

Understanding aging-related cognitive decline is of growing importance in aging societies, but relatively little is known about its neural substrates. Measures of white matter microstructure are known to correlate cross-sectionally with cognitive ability measures, but only a few small studies have tested for longitudinal relations among these variables. We tested whether there were coupled changes in brain white matter microstructure indexed by fractional anisotropy (FA) and three broad cognitive domains (fluid intelligence, processing speed, and memory) in a large cohort of human participants with longitudinal diffusion tensor MRI and detailed cognitive data taken at ages 73 years (n = 731) and 76 years (n = 488). Longitudinal changes in white matter microstructure were coupled with changes in fluid intelligence, but not with processing speed or memory. Individuals with higher baseline white matter FA showed less subsequent decline in processing speed. Our results provide evidence for a longitudinal link between changes in white matter microstructure and aging-related cognitive decline during the eighth decade of life. They are consistent with theoretical perspectives positing that a corticocortical "disconnection" partly explains cognitive aging. Copyright © 2015 Ritchie et al.

Neurobehavioural sequelae following cranial irradiation and chemotherapy in children: an analysis of risk factors.

PubMed

Anderson, V; Godber, T; Smibert, E; Ekert, H

1997-01-01

Neurobehavioural deficits are commonly reported following treatment for childhood cancers. This study examined the impact of cranial irradiation (CRT) and chemotherapy in children, aiming to identify factors detrimental to long-term outcome. The study compared survivors of acute lymphoblastic leukemia (ALL), treated with CRT and chemotherapy (CRT group: n = 100), survivors of cancers treated with chemotherapy only (n = 50) and healthy controls (n = 100) for intelligence, academic achievement, information processing, learning, and executive function. CRT and chemotherapy in combination were associated with reduced intelligence, educational skill, immediate memory, processing speed, and executive function. Children treated with chemotherapy alone exhibited subtle information processing deficits. Within the CRT group, younger age at treatment was predictive of deficits in non-verbal ability, educational skills and executive functions. High dose CRT was associated with poorer information processing and lower arithmetic ability.

Physical and electrical properties of melt-spun Fe-Si (3–8 wt%) soft magnetic ribbons

DOE PAGES

Overman, Nicole R.; Jiang, Xiujuan; Kukkadapu, Ravi K.; ...

2017-12-13

Fe-Si alloys ranging from 3 to 8 wt% Si were rapidly solidified using melt spinning. Wheel speeds of 30 m/s and 40 m/s were employed to vary cooling rates. Mössbauer spectroscopic studies indicated the Si content significantly influenced the number of Fe sites, relative abundance of various Fe species, and internal magnetic fields/structural environments. Wheel speed altered Fe speciation only in the 3 wt% sample. Scanning electron microscopy confirmed that increasing the wheel speed refined both the ribbon thickness and grain size. Electron backscatter diffraction results suggest tailoring melt spinning process parameters and alloy chemistry may offer the ability tomore » manipulate {001} texture development. In conclusion, electrical resistivity measurements were observed to increase in response to elevated Si content. Increased hardness was correlated to elevated Si content and wheel speed.« less

Physical and electrical properties of melt-spun Fe-Si (3–8 wt.%) soft magnetic ribbons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Overman, Nicole R.; Jiang, Xiujuan; Kukkadapu, Ravi K.

Fe-Si alloys ranging from 3 to 8 wt% Si were rapidly solidified using melt spinning. Wheel speeds of 30 m/s and 40 m/s were employed to vary cooling rates. Mössbauer spectroscopic studies indicated the Si content significantly influenced the number of Fe sites, relative abundance of various Fe species, and internal magnetic fields/structural environments. Wheel speed altered Fe speciation only in the 3 wt% sample. Scanning electron microscopy confirmed that increasing the wheel speed refined both the ribbon thickness and grain size. Electron backscatter diffraction results suggest tailoring melt spinning process parameters and alloy chemistry may offer the ability tomore » manipulate {001} texture development. Electrical resistivity measurements were observed to increase in response to elevated Si content. Increased hardness was correlated to elevated Si content and wheel speed.« less

Physical and electrical properties of melt-spun Fe-Si (3–8 wt%) soft magnetic ribbons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Overman, Nicole R.; Jiang, Xiujuan; Kukkadapu, Ravi K.

Fe-Si alloys ranging from 3 to 8 wt% Si were rapidly solidified using melt spinning. Wheel speeds of 30 m/s and 40 m/s were employed to vary cooling rates. Mössbauer spectroscopic studies indicated the Si content significantly influenced the number of Fe sites, relative abundance of various Fe species, and internal magnetic fields/structural environments. Wheel speed altered Fe speciation only in the 3 wt% sample. Scanning electron microscopy confirmed that increasing the wheel speed refined both the ribbon thickness and grain size. Electron backscatter diffraction results suggest tailoring melt spinning process parameters and alloy chemistry may offer the ability tomore » manipulate {001} texture development. In conclusion, electrical resistivity measurements were observed to increase in response to elevated Si content. Increased hardness was correlated to elevated Si content and wheel speed.« less

Scientific Visualization in High Speed Network Environments

NASA Technical Reports Server (NTRS)

Vaziri, Arsi; Kutler, Paul (Technical Monitor)

1997-01-01

In several cases, new visualization techniques have vastly increased the researcher's ability to analyze and comprehend data. Similarly, the role of networks in providing an efficient supercomputing environment have become more critical and continue to grow at a faster rate than the increase in the processing capabilities of supercomputers. A close relationship between scientific visualization and high-speed networks in providing an important link to support efficient supercomputing is identified. The two technologies are driven by the increasing complexities and volume of supercomputer data. The interaction of scientific visualization and high-speed networks in a Computational Fluid Dynamics simulation/visualization environment are given. Current capabilities supported by high speed networks, supercomputers, and high-performance graphics workstations at the Numerical Aerodynamic Simulation Facility (NAS) at NASA Ames Research Center are described. Applied research in providing a supercomputer visualization environment to support future computational requirements are summarized.

The STEP model: Characterizing simultaneous time effects on practice for flight simulator performance among middle-aged and older pilots.

PubMed

Kennedy, Quinn; Taylor, Joy; Noda, Art; Yesavage, Jerome; Lazzeroni, Laura C

2015-09-01

Understanding the possible effects of the number of practice sessions (practice) and time between practice sessions (interval) among middle-aged and older adults in real-world tasks has important implications for skill maintenance. Prior training and cognitive ability may impact practice and interval effects on real-world tasks. In this study, we took advantage of existing practice data from 5 simulated flights among 263 middle-aged and older pilots with varying levels of flight expertise (defined by U.S. Federal Aviation Administration proficiency ratings). We developed a new Simultaneous Time Effects on Practice (STEP) model: (a) to model the simultaneous effects of practice and interval on performance of the 5 flights, and (b) to examine the effects of selected covariates (i.e., age, flight expertise, and 3 composite measures of cognitive ability). The STEP model demonstrated consistent positive practice effects, negative interval effects, and predicted covariate effects. Age negatively moderated the beneficial effects of practice. Additionally, cognitive processing speed and intraindividual variability (IIV) in processing speed moderated the benefits of practice and/or the negative influence of interval for particular flight performance measures. Expertise did not interact with practice or interval. Results indicated that practice and interval effects occur in simulated flight tasks. However, processing speed and IIV may influence these effects, even among high-functioning adults. Results have implications for the design and assessment of training interventions targeted at middle-aged and older adults for complex real-world tasks. (c) 2015 APA, all rights reserved).

Explaining the association between music training and reading in adults.

PubMed

Swaminathan, Swathi; Schellenberg, E Glenn; Venkatesan, Kirthika

2018-06-01

We sought to clarify whether the positive association between music lessons and reading ability is explained better by shared resources for processing pitch and temporal information, or by general cognitive abilities. Participants were native and nonnative speakers of English with varying levels of music training. We measured reading ability (comprehension and speed), music-perception skills (melody and rhythm), general cognitive ability (nonverbal intelligence, short-term memory, and working memory), and socioeconomic status (SES; family income, parents' education). Reading ability was associated positively with music training, English as a native language, and general cognitive ability. The association between reading and music training was significant after SES, native language, and music-perception skills were controlled. After general cognitive abilities were held constant, however, there was no longer an association between reading and music training. These findings suggest that the association between reading ability and music training is a consequence of general cognitive abilities. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Exploring Expressive Vocabulary Variability in Two-Year-Olds: The Role of Working Memory

ERIC Educational Resources Information Center

Newbury, Jayne; Klee, Thomas; Stokes, Stephanie F.; Moran, Catherine

2015-01-01

Purpose: This study explored whether measures of working memory ability contribute to the wide variation in 2-year-olds' expressive vocabulary skills. Method: Seventy-nine children (aged 24-30 months) were assessed by using standardized tests of vocabulary and visual cognition, a processing speed measure, and behavioral measures of verbal working…

A Cognitive Cascade in Infancy: Pathways from Prematurity to Later Mental Development

ERIC Educational Resources Information Center

Rose, Susan A.; Feldman, Judith F.; Jankowski, Jeffery J.; Rossem, Ronan V.

2008-01-01

Using data from a longitudinal study of preterms and full-terms, the present study examined the structure of infant cognition at 12 months, the extent to which five 12-month abilities (attention, processing speed, recognition, recall, and representational competence) mediated the relation from prematurity to mental development at 2-3 years, and…

Factors influencing laser cutting of wood

Treesearch

V.G. Barnekov; C.W. McMillin; H.A. Huber

1986-01-01

Factors influencing the ability of lasers to cut wood may be generally classified into these three areas: 1) characteristics of the laser beam; 2) equipment and processing variables; and 3) properties of the workpiece. Effects of beam power, mode, polarization, and stability are discussed as are aspects of optics, location of focal point, feed speed, gas-jet assist...

L2 Speaking Development during Study Abroad: Fluency, Accuracy, Complexity, and Underlying Cognitive Factors

ERIC Educational Resources Information Center

Leonard, Karen Ruth; Shea, Christine E.

2017-01-01

We take a multidimensional perspective on the development of second language (L2) speaking ability and examine how changes in the underlying cognitive variables of linguistic knowledge and processing speed interact with complexity, fluency, and accuracy over the course of a 3-month Spanish study abroad session. Study abroad provides a unique…

Acute and Chronic Altitude-Induced Cognitive Dysfunction in Children and Adolescents.

PubMed

Rimoldi, Stefano F; Rexhaj, Emrush; Duplain, Hervé; Urben, Sébastien; Billieux, Joël; Allemann, Yves; Romero, Catherine; Ayaviri, Alejandro; Salinas, Carlos; Villena, Mercedes; Scherrer, Urs; Sartori, Claudio

2016-02-01

To assess whether exposure to high altitude induces cognitive dysfunction in young healthy European children and adolescents during acute, short-term exposure to an altitude of 3450 m and in an age-matched European population permanently living at this altitude. We tested executive function (inhibition, shifting, and working memory), memory (verbal, short-term visuospatial, and verbal episodic memory), and speed processing ability in: (1) 48 healthy nonacclimatized European children and adolescents, 24 hours after arrival at high altitude and 3 months after return to low altitude; (2) 21 matched European subjects permanently living at high altitude; and (3) a matched control group tested twice at low altitude. Short-term hypoxia significantly impaired all but 2 (visuospatial memory and processing speed) of the neuropsychological abilities that were tested. These impairments were even more severe in the children permanently living at high altitude. Three months after return to low altitude, the neuropsychological performances significantly improved and were comparable with those observed in the control group tested only at low altitude. Acute short-term exposure to an altitude at which major tourist destinations are located induces marked executive and memory deficits in healthy children. These deficits are equally marked or more severe in children permanently living at high altitude and are expected to impair their learning abilities. Copyright © 2016 Elsevier Inc. All rights reserved.

The ACTIVE conceptual framework as a structural equation model.

PubMed

Gross, Alden L; Payne, Brennan R; Casanova, Ramon; Davoudzadeh, Pega; Dzierzewski, Joseph M; Farias, Sarah; Giovannetti, Tania; Ip, Edward H; Marsiske, Michael; Rebok, George W; Schaie, K Warner; Thomas, Kelsey; Willis, Sherry; Jones, Richard N

2018-01-01

Background/Study Context: Conceptual frameworks are analytic models at a high level of abstraction. Their operationalization can inform randomized trial design and sample size considerations. The Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) conceptual framework was empirically tested using structural equation modeling (N=2,802). ACTIVE was guided by a conceptual framework for cognitive training in which proximal cognitive abilities (memory, inductive reasoning, speed of processing) mediate treatment-related improvement in primary outcomes (everyday problem-solving, difficulty with activities of daily living, everyday speed, driving difficulty), which in turn lead to improved secondary outcomes (health-related quality of life, health service utilization, mobility). Measurement models for each proximal, primary, and secondary outcome were developed and tested using baseline data. Each construct was then combined in one model to evaluate fit (RMSEA, CFI, normalized residuals of each indicator). To expand the conceptual model and potentially inform future trials, evidence of modification of structural model parameters was evaluated by age, years of education, sex, race, and self-rated health status. Preconceived measurement models for memory, reasoning, speed of processing, everyday problem-solving, instrumental activities of daily living (IADL) difficulty, everyday speed, driving difficulty, and health-related quality of life each fit well to the data (all RMSEA < .05; all CFI > .95). Fit of the full model was excellent (RMSEA = .038; CFI = .924). In contrast with previous findings from ACTIVE regarding who benefits from training, interaction testing revealed associations between proximal abilities and primary outcomes are stronger on average by nonwhite race, worse health, older age, and less education (p < .005). Empirical data confirm the hypothesized ACTIVE conceptual model. Findings suggest that the types of people who show intervention effects on cognitive performance potentially may be different from those with the greatest chance of transfer to real-world activities.

The Interaction of High-Speed Turbulence with Flames

NASA Astrophysics Data System (ADS)

Poludnenko, Alexei Y.; Oran, E. S.

2010-01-01

Interaction of flames with turbulence occurs in systems ranging from chemical flames on Earth to thermonuclear burning fronts, which are presently believed to be the key component of the explosion mechanism powering the type Ia supernovae. A number of important questions remains concerning the dynamics of turbulent flames in the presence of high-speed turbulence, the flame structure and stability, as well as the ability of the turbulent cascade to penetrate and disrupt the flame creating the distributed mode of burning. We present results of a systematic study of the dynamics and properties of turbulent flames formed under the action of high-speed turbulence using a simplified one-step kinetics similar to the one used to describe hydrogen combustion. This approach makes large-scale highly resolved simulations computationally feasible and it allows one to focus on the process of the turbulence-flame interaction in a simplified controlled setting. Numerical simulations were performed using the massively parallel reactive-flow code Athena-RFX. We discuss global properties of the turbulent flame in this regime (flame width, speed, etc.) and the internal structure of the flame brush. A method is presented for directly reconstructing the internal flame structure and it is shown that correct characterization of the flame regime can be very sensitive to the proper choice of the diagnostic method. We discuss the ability of the turbulent cascade to penetrate the internal flame structure. Finally, we also consider the processes that determine the turbulent burning velocity and identify two distinct regimes of flame evolution. This work was supported in part by the National Research Council, Naval Research Laboratory, and the Office of Naval Research, and by the National Science Foundation through the TeraGrid resources.

The numerical simulation and experiment on extrusion roller embossing of light diffusion plate with micro-structure

NASA Astrophysics Data System (ADS)

Zang, Gongzheng; Fu, Zhihong; Zhang, Lei; Wan, Yue

2018-01-01

Extrusion roller embossing process has demonstrated the ability to produce polymer film with micro-structure. However the influence of various parameters on the forming quality has not been understood clearly. In this paper, a light diffusion plate with semi cylindrical micro-structure array as the research object, the influence of the main processing parameters such as roller speed, pressuring distance and polymer film temperature to the rolling quality was investigated in detail by simulation and experimental methods. The results show that the thickness of the light diffusion plate and the micro-structure fitting diameter increases with the increasing of the roll speed and the polymer film temperature, and decreases with the increasing of the pressing distance. Besides, the simulation results conformed well to the experimental results.

Relationships Between Oral Reading Rates for Letters, Words, and Simple Text, and the Development of Reading Ability.

ERIC Educational Resources Information Center

Biemiller, Andrew

The development of oral reading speed in the early elementary years and an examination of some underlying abilities that may be involved in individual differences in reading speed and ability are the concerns of this study. Cross-sectional and longitudinal data relating the time required to read orally 50 unrelated letters, 50 unrelated words, and…

Integrated diversification of locomotion and feeding in labrid fishes.

PubMed

Collar, David C; Wainwright, Peter C; Alfaro, Michael E

2008-02-23

An organism's performance of any ecological task involves coordination of multiple functional systems. Feeding performance is influenced by locomotor abilities which are used during search and capture of prey, as well as cranial mechanics, which affect prey capture and processing. But, does this integration of functional systems manifest itself during evolution? We asked whether the locomotor and feeding systems evolved in association in one of the most prominent and diverse reef fish radiations, the Labridae. We examined features of the pectoral fins that affect swimming performance and aspects of the skull that describe force and motion of the jaws. We applied a recent phylogeny, calculated independent contrasts for 60 nodes and performed principal components analyses separately on contrasts for fin and skull traits. The major axes of fin and skull diversification are highly correlated; modifications of the skull to amplify the speed of jaw movements are correlated with changes in the pectoral fins that increase swimming speed, and increases in force capacity of the skull are associated with changes towards fins that produce high thrust at slow speeds. These results indicate that the labrid radiation involved a strong connection between locomotion and feeding abilities.

Lithium and cognition in those with bipolar disorder.

PubMed

Paterson, Amelia; Parker, Gordon

2017-03-01

Although a percentage of patients report cognitive side-effects when taking lithium, it can be difficult to determine from the literature whether any cognitive changes reflect lithium itself, the lithium serum level, residual mood symptoms, the underlying nature of bipolar disorder, or biological alterations such as hypothyroidism. This review was carried out to synthesize and evaluate relevant literature examining any cognitive impact of lithium in those with bipolar disorder. The effect of lithium in those with bipolar disorder was examined across the cognitive domains of attention, psychomotor speed, processing speed, working memory, intellectual functioning, verbal memory, visual memory, and executive functioning by reviewing the published empirical literature. Any impact of hypothyroidism and lithium toxicity was also examined. The literature supports the conclusion that lithium has a distinct impact on psychomotor speed in participants with bipolar disorder. In contrast, there appears to be no impact on attention. Any impact of lithium on memory in patients with bipolar disorder is unclear as the literature is contradictory and any such effect may be overshadowed by the greater impact of residual mood symptoms. The impact on processing speed, intellectual abilities, and executive functioning also remains unclear. Several clinical management strategies are recommended.

Barriers to physical activity between adults with stroke and their care partners.

PubMed

Zalewski, Kathryn R; Dvorak, Leah

2011-10-01

Healthy living includes meeting daily physical activity guidelines. This study compares daily physical activity rates and barriers to physical activity for people with stroke and their partners (spouse or significant other). Physical abilities, energy expenditure, daily steps, and barriers to physical activity are evaluated in people who have completed stroke rehabilitation and their partners. Twenty pairs of adults (mean age 69.7 years) participated. Participants with stroke were classified as sedentary, averaging 2,990 (± 2,488) steps per day. Their partners are classified as low active, averaging 6,378 (± 2,149) steps per day. For stroke survivors, physical abilities were positively correlated to daily activity rates. The number of steps walked per day was moderately correlated to 6-minute walk tests (r = 0.550, P < .05), comfortable gait speeds (r = 0.588, P < .05), and fast gait speeds (r = 0.677, P < .01). For care partners, physical abilities were not correlated to daily physical activity. People with stroke report lack of skill as a primary barrier; their partners report lack of time. The relationship between physical ability and physical activity is reinforced with this study. The impact of stroke on the family, particularly on time demands of the primary caregiver, suggests the needs of the care partner may not be adequately addressed in the rehabilitation process.

Using modified fruit fly optimisation algorithm to perform the function test and case studies

NASA Astrophysics Data System (ADS)

Pan, Wen-Tsao

2013-06-01

Evolutionary computation is a computing mode established by practically simulating natural evolutionary processes based on the concept of Darwinian Theory, and it is a common research method. The main contribution of this paper was to reinforce the function of searching for the optimised solution using the fruit fly optimization algorithm (FOA), in order to avoid the acquisition of local extremum solutions. The evolutionary computation has grown to include the concepts of animal foraging behaviour and group behaviour. This study discussed three common evolutionary computation methods and compared them with the modified fruit fly optimization algorithm (MFOA). It further investigated the ability of the three mathematical functions in computing extreme values, as well as the algorithm execution speed and the forecast ability of the forecasting model built using the optimised general regression neural network (GRNN) parameters. The findings indicated that there was no obvious difference between particle swarm optimization and the MFOA in regards to the ability to compute extreme values; however, they were both better than the artificial fish swarm algorithm and FOA. In addition, the MFOA performed better than the particle swarm optimization in regards to the algorithm execution speed, and the forecast ability of the forecasting model built using the MFOA's GRNN parameters was better than that of the other three forecasting models.

Intervention for a multi-character processing deficit in a Greek-speaking child with surface dyslexia.

PubMed

Niolaki, Georgia Z; Masterson, Jackie

2013-01-01

A case study with a 12-year-old boy, R.F., who was a monolingual speaker of Greek is reported. R.F. showed slow word reading and a difficulty in spelling irregular words but not nonwords. Assessments revealed that R.F. did not appear to have a phonological deficit, but indicated impaired multicharacter processing ability for visually presented letter arrays. On the basis of previous research linking multicharacter processing and reading we developed an intervention aimed at improving R.F.'s ability to report letter arrays of increasing length. Following a 9-week programme, improvement was observed, and investigation of R.F.'s reading revealed gains in single word reading speed and accuracy. The findings support the significance of intervention studies for testing hypotheses regarding causal relationships among cognitive processes and the notion of specific profiles of developmental dyslexia/dysgraphia in both opaque and transparent orthographies.

Multicomponent analysis of a digital Trail Making Test.

PubMed

Fellows, Robert P; Dahmen, Jessamyn; Cook, Diane; Schmitter-Edgecombe, Maureen

2017-01-01

The purpose of the current study was to use a newly developed digital tablet-based variant of the TMT to isolate component cognitive processes underlying TMT performance. Similar to the paper-based trail making test, this digital variant consists of two conditions, Part A and Part B. However, this digital version automatically collects additional data to create component subtest scores to isolate cognitive abilities. Specifically, in addition to the total time to completion and number of errors, the digital Trail Making Test (dTMT) records several unique components including the number of pauses, pause duration, lifts, lift duration, time inside each circle, and time between circles. Participants were community-dwelling older adults who completed a neuropsychological evaluation including measures of processing speed, inhibitory control, visual working memory/sequencing, and set-switching. The abilities underlying TMT performance were assessed through regression analyses of component scores from the dTMT with traditional neuropsychological measures. Results revealed significant correlations between paper and digital variants of Part A (r s  = .541, p < .001) and paper and digital versions of Part B (r s  = .799, p < .001). Regression analyses with traditional neuropsychological measures revealed that Part A components were best predicted by speeded processing, while inhibitory control and visual/spatial sequencing were predictors of specific components of Part B. Exploratory analyses revealed that specific dTMT-B components were associated with a performance-based medication management task. Taken together, these results elucidate specific cognitive abilities underlying TMT performance, as well as the utility of isolating digital components.

Cognitive Abilities Underlying Reading Accuracy, Fluency and Spelling Acquisition in Korean Hangul Learners from Grades 1 to 4: A Cross-Sectional Study.

PubMed

Park, Hyun-Rin; Uno, Akira

2015-08-01

The purpose of this cross-sectional study was to examine the cognitive abilities that predict reading and spelling performance in Korean children in Grades 1 to 4, depending on expertise and reading experience. As a result, visual cognition, phonological awareness, naming speed and receptive vocabulary significantly predicted reading accuracy in children in Grades 1 and 2, whereas visual cognition, phonological awareness and rapid naming speed did not predict reading accuracy in children in higher grades. For reading, fluency, phonological awareness, rapid naming speed and receptive vocabulary were crucial abilities in children in Grades 1 to 3, whereas phonological awareness was not a significant predictor in children in Grade 4. In spelling, reading ability and receptive vocabulary were the most important abilities for accurate Hangul spelling. The results suggested that the degree of cognitive abilities required for reading and spelling changed depending on expertise and reading experience. Copyright © 2015 John Wiley & Sons, Ltd.

Cognitive Predictors of Calculations and Number Line Estimation with Whole Numbers and Fractions among At-Risk Students

ERIC Educational Resources Information Center

Namkung, Jessica M.; Fuchs, Lynn S.

2015-01-01

The purpose of this study was to examine the cognitive predictors of calculations and number line estimation with whole numbers and fractions. At-risk 4th-grade students (N = 139) were assessed on 7 domain-general abilities (i.e., working memory, processing speed, concept formation, language, attentive behavior, and nonverbal reasoning) and…

Cognitive Predictors of Calculations and Number Line Estimation with Whole Numbers and Fractions among At-Risk Students

ERIC Educational Resources Information Center

Namkung, Jessica M.; Fuchs, Lynn S.

2016-01-01

The purpose of this study was to examine the cognitive predictors of calculations and number line estimation with whole numbers and fractions. At-risk 4th-grade students (N = 139) were assessed on 6 domain-general abilities (i.e., working memory, processing speed, concept formation, language, attentive behavior, and nonverbal reasoning) and…

White Matter Maturation Supports the Development of Reasoning Ability through Its Influence on Processing Speed

ERIC Educational Resources Information Center

Ferrer, Emilio; Whitaker, Kirstie J.; Steele, Joel S.; Green, Chloe T.; Wendelken, Carter; Bunge, Silvia A.

2013-01-01

The structure of the human brain changes in several ways throughout childhood and adolescence. Perhaps the most salient of these changes is the strengthening of white matter tracts that enable distal brain regions to communicate with one another more quickly and efficiently. Here, we sought to understand whether and how white matter changes…

Dynamic modeling of GMA fillet welding using cross-correlation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hellinga, M.; Huissoon, J.; Kerr, H.

1996-12-31

The feasibility of employing the cross-correlation system identification technique as a dynamic modeling method for the GMAW process was examined. This approach has the advantages of modeling speed, the ability to operate in low signal to noise environments, the ease of digital implementation, and the lack of model order assumption, making it ideal in a welding application. The width of the weld pool was the parameter investigated as a function of torch travel speed. Both on-line and off-line width measurements were used to identify the impulse response. Experimental results are presented and comparisons made with both step and ramp response.

The Relationship between the Current Waveform just before the Current Zero and the Interruption Ability in the High-speed VCB

NASA Astrophysics Data System (ADS)

Niwa, Yoshimitsu; Matsuzaki, Jun; Yokokura, Kunio

The high-speed vacuum circuit breaker, which forced the fault current to zero was investigated. The test circuit breaker consisted of a vacuum interrupter and a high frequency current source. The vacuum interrupter, which had the axial magnetic field electrode and the disk shape electrode, was tested. The arcing period of the high-speed vacuum circuit breaker is much shorter than that of conventional circuit breaker. The arc behavior of the test electrodes immediately after the contact separation was observed by a high-speed video camcorder. The relation between the current waveform just before the current zero and the interruption ability by varying the high frequency current source was investigated experimentally. The results demonstrate the interruption ability and the arc behavior of the high-speed vacuum circuit breaker. The high current interruption was made possible by the low current period just before the current zero, although the arcing time is short and the arc is concentrated.

Balance ability and cognitive impairment influence sustained walking in an assisted living facility.

PubMed

Bowen, Mary Elizabeth; Crenshaw, Jeremy; Stanhope, Steven J

The purpose of this study was to determine the influence of cognitive impairment (CI), 1 gait quality, and balance ability on walking distance and speed in an assisted living facility. This was a longitudinal cohort study of institutionalized older adults (N = 26; 555 observations) followed for up to 8 months. Hierarchical linear modeling statistical techniques were used to examine the effects of gait quality and balance ability (using the Tinetti Gait and Balance Test) and cognitive status (using the Montreal Cognitive Assessment) on walking activity (distance, sustained distance, sustained speed). The latter were measured objectively and continuously by a real-time locating system (RTLS). A one-point increase in balance ability was associated with an 8% increase in sustained walking distance (p = 0.03) and a 4% increase in sustained gait speed (p = 0.00). Gait quality was associated with decreased sustained gait speed (p = 0.03). Residents with moderate (ERR = 2.34;p = 0.01) or severe CI (trend with an ERR = 1.62; p = 0.06) had longer sustained walking distances at slower speeds when compared to residents with no CI. After accounting for cognitive status, it was balance ability, not gait quality, that was a determinant of sustained walking distances and speeds. Therefore, balance interventions for older adults in assisted living may enable sustained walking activity. Given that CI was associated with more sustained walking, limiting sustained walking in the form of wandering behavior, especially for those with balance impairments, may prevent adverse events, including fall-related injury. Published by Elsevier B.V.

How muscle fiber lengths and velocities affect muscle force generation as humans walk and run at different speeds

PubMed Central

Arnold, Edith M.; Hamner, Samuel R.; Seth, Ajay; Millard, Matthew; Delp, Scott L.

2013-01-01

SUMMARY The lengths and velocities of muscle fibers have a dramatic effect on muscle force generation. It is unknown, however, whether the lengths and velocities of lower limb muscle fibers substantially affect the ability of muscles to generate force during walking and running. We examined this issue by developing simulations of muscle–tendon dynamics to calculate the lengths and velocities of muscle fibers from electromyographic recordings of 11 lower limb muscles and kinematic measurements of the hip, knee and ankle made as five subjects walked at speeds of 1.0–1.75 m s−1 and ran at speeds of 2.0–5.0 m s−1. We analyzed the simulated fiber lengths, fiber velocities and forces to evaluate the influence of force–length and force–velocity properties on force generation at different walking and running speeds. The simulations revealed that force generation ability (i.e. the force generated per unit of activation) of eight of the 11 muscles was significantly affected by walking or running speed. Soleus force generation ability decreased with increasing walking speed, but the transition from walking to running increased the force generation ability by reducing fiber velocities. Our results demonstrate the influence of soleus muscle architecture on the walk-to-run transition and the effects of muscle–tendon compliance on the plantarflexors' ability to generate ankle moment and power. The study presents data that permit lower limb muscles to be studied in unprecedented detail by relating muscle fiber dynamics and force generation to the mechanical demands of walking and running. PMID:23470656

Interaction of attentional and motor control processes in handwriting.

PubMed

Brown, T L; Donnenwirth, E E

1990-01-01

The interaction between attentional capacity, motor control processes, and strategic adaptations to changing task demands was investigated in handwriting, a continuous (rather than discrete) skilled performance. Twenty-four subjects completed 12 two-minute handwriting samples under instructions stressing speeded handwriting, normal handwriting, or highly legible handwriting. For half of the writing samples, a concurrent auditory monitoring task was imposed. Subjects copied either familiar (English) or unfamiliar (Latin) passages. Writing speed, legibility ratings, errors in writing and in the secondary auditory task, and a derived measure of the average number of characters held in short-term memory during each sample ("planning unit size") were the dependent variables. The results indicated that the ability to adapt to instructions stressing speed or legibility was substantially constrained by the concurrent listening task and by text familiarity. Interactions between instructions, task concurrence, and text familiarity in the legibility ratings, combined with further analyses of planning unit size, indicated that information throughput from temporary storage mechanisms to motor processes mediated the loss of flexibility effect. Overall, the results suggest that strategic adaptations of a skilled performance to changing task circumstances are sensitive to concurrent attentional demands and that departures from "normal" or "modal" performance require attention.

BBMerge – Accurate paired shotgun read merging via overlap

DOE PAGES

Bushnell, Brian; Rood, Jonathan; Singer, Esther

2017-10-26

Merging paired-end shotgun reads generated on high-throughput sequencing platforms can substantially improve various subsequent bioinformatics processes, including genome assembly, binning, mapping, annotation, and clustering for taxonomic analysis. With the inexorable growth of sequence data volume and CPU core counts, the speed and scalability of read-processing tools becomes ever-more important. The accuracy of shotgun read merging is crucial as well, as errors introduced by incorrect merging percolate through to reduce the quality of downstream analysis. Thus, we designed a new tool to maximize accuracy and minimize processing time, allowing the use of read merging on larger datasets, and in analyses highlymore » sensitive to errors. We present BBMerge, a new merging tool for paired-end shotgun sequence data. We benchmark BBMerge by comparison with eight other widely used merging tools, assessing speed, accuracy and scalability. Evaluations of both synthetic and real-world datasets demonstrate that BBMerge produces merged shotgun reads with greater accuracy and at higher speed than any existing merging tool examined. BBMerge also provides the ability to merge non-overlapping shotgun read pairs by using k-mer frequency information to assemble the unsequenced gap between reads, achieving a significantly higher merge rate while maintaining or increasing accuracy.« less

BBMerge – Accurate paired shotgun read merging via overlap

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bushnell, Brian; Rood, Jonathan; Singer, Esther

Merging paired-end shotgun reads generated on high-throughput sequencing platforms can substantially improve various subsequent bioinformatics processes, including genome assembly, binning, mapping, annotation, and clustering for taxonomic analysis. With the inexorable growth of sequence data volume and CPU core counts, the speed and scalability of read-processing tools becomes ever-more important. The accuracy of shotgun read merging is crucial as well, as errors introduced by incorrect merging percolate through to reduce the quality of downstream analysis. Thus, we designed a new tool to maximize accuracy and minimize processing time, allowing the use of read merging on larger datasets, and in analyses highlymore » sensitive to errors. We present BBMerge, a new merging tool for paired-end shotgun sequence data. We benchmark BBMerge by comparison with eight other widely used merging tools, assessing speed, accuracy and scalability. Evaluations of both synthetic and real-world datasets demonstrate that BBMerge produces merged shotgun reads with greater accuracy and at higher speed than any existing merging tool examined. BBMerge also provides the ability to merge non-overlapping shotgun read pairs by using k-mer frequency information to assemble the unsequenced gap between reads, achieving a significantly higher merge rate while maintaining or increasing accuracy.« less

Demonstration of paper cutting using single emitter laser diode and infrared-absorbing ink.

PubMed

Pagès, Hubert; Piombini, Hervé; Enguehard, Franck; Acher, Olivier

2005-04-04

We show that conventional paper can be cut using a 1W laser diode, provided the cutting lines are first traced using a proper ink. The ink should absorb the laser light, and penetrate deep into the paper. An "invisible ink" that is transparent in the visible range and absorbing in the infrared has been successfully tested. The paper is tidily cut. The laser power required to cut the paper is proportional to the displacement speed of the paper. Cutting speeds exceeding 3 cm.s-1.W-1 have been demonstrated. At higher speeds, the paper is not cut through, but easy-tearable lines and easy-folding lines are obtained. The whole inking and laser cutting process may be integrated into next generations of personal inkjet printers and expand document creation abilities.

High speed automated microtomography of nuclear emulsions and recent application

NASA Astrophysics Data System (ADS)

Tioukov, V.; Aleksandrov, A.; Consiglio, L.; De Lellis, G.; Vladymyrov, M.

2015-12-01

The development of high-speed automatic scanning systems was the key-factor for massive and successful emulsions application for big neutrino experiments like OPERA. The emulsion detector simplicity, the unprecedented sub-micron spatial resolution and the unique ability to provide intrinsically 3-dimensional spatial information make it a perfect device for short-living particles study, where the event topology should be precisely reconstructed in a 10-100 um scale vertex region. Recently the exceptional technological progress in image processing and automation together with intensive R&D done by Italian and Japanese microscopy groups permit to increase the scanning speed to unbelievable few years ago m2/day scale and so greatly extend the range of the possible applications for emulsion-based detectors to other fields like: medical imaging, directional dark matter search, nuclear physics, geological and industrial applications.

Speed Pressure in Conflict Situations Impedes Inhibitory Action Control in Parkinson’s Disease

PubMed Central

Van Wouwe, N.C.; van den Wildenberg, W.P.M.; Claassen, D.O.; Kanoff, K.; Bashore, T.R.; Wylie, S.A.

2014-01-01

Parkinson’s disease (PD) is a neurodegenerative basal ganglia disease that disrupts cognitive control processes involved in response selection. The current study investigated the effects of PD on the ability to resolve conflicts during response selection when performance emphasized response speed versus response accuracy. Twenty-one (21) PD patients and 21 healthy controls (HC) completed a Simon conflict task, and a subset of 10 participants from each group provided simultaneous movement-related potential (MRP) data to track patterns of motor cortex activation and inhibition associated with the successful resolution of conflicting response tendencies. Both groups adjusted performance strategically to emphasize response speed or accuracy (i.e., speed-accuracy effect). For HC, interference from a conflicting response was reduced when response accuracy rather than speed was prioritized. For PD patients, however, there was a reduction in interference, but it was not statistically significant. The conceptual framework of the Dual-Process Activation-Suppression (DPAS) model revealed that the groups experienced similar susceptibility to making fast impulsive errors in conflict trials irrespective of speed-accuracy instructions, but PD patients were less proficient and delayed compared to HC at suppressing the interference from these incorrect response tendencies, especially under speed pressure. Analysis of MRPs on response conflict trials showed attenuated inhibition of the motor cortex controlling the conflicting impulsive response tendency in PD patients compared to HC. These results further confirm the detrimental effects of PD inhibitory control mechanisms and their exacerbation when patients perform under speed pressure. The results also suggest that a downstream effect of inhibitory dysfunction in PD is diminished inhibition of motor cortex controlling conflicting response tendencies. PMID:25017503

Speed of Language Comprehension at 18 Months Old Predicts School-Relevant Outcomes at 54 Months Old in Children Born Preterm.

PubMed

Marchman, Virginia A; Loi, Elizabeth C; Adams, Katherine A; Ashland, Melanie; Fernald, Anne; Feldman, Heidi M

2018-04-01

Identifying which preterm (PT) children are at increased risk of language and learning differences increases opportunities for participation in interventions that improve outcomes. Speed in spoken language comprehension at early stages of language development requires information processing skills that may form the foundation for later language and school-relevant skills. In children born full-term, speed of comprehending words in an eye-tracking task at 2 years old predicted language and nonverbal cognition at 8 years old. Here, we explore the extent to which speed of language comprehension at 1.5 years old predicts both verbal and nonverbal outcomes at 4.5 years old in children born PT. Participants were children born PT (n = 47; ≤32 weeks gestation). Children were tested in the "looking-while-listening" task at 18 months old, adjusted for prematurity, to generate a measure of speed of language comprehension. Parent report and direct assessments of language were also administered. Children were later retested on a test battery of school-relevant skills at 4.5 years old. Speed of language comprehension at 18 months old predicted significant unique variance (12%-31%) in receptive vocabulary, global language abilities, and nonverbal intelligence quotient (IQ) at 4.5 years, controlling for socioeconomic status, gestational age, and medical complications of PT birth. Speed of language comprehension remained uniquely predictive (5%-12%) when also controlling for children's language skills at 18 months old. Individual differences in speed of spoken language comprehension may serve as a marker for neuropsychological processes that are critical for the development of school-relevant linguistic skills and nonverbal IQ in children born PT.

Adaptive Neuro-Fuzzy Determination of the Effect of Experimental Parameters on Vehicle Agent Speed Relative to Vehicle Intruder.

PubMed

Shamshirband, Shahaboddin; Banjanovic-Mehmedovic, Lejla; Bosankic, Ivan; Kasapovic, Suad; Abdul Wahab, Ainuddin Wahid Bin

2016-01-01

Intelligent Transportation Systems rely on understanding, predicting and affecting the interactions between vehicles. The goal of this paper is to choose a small subset from the larger set so that the resulting regression model is simple, yet have good predictive ability for Vehicle agent speed relative to Vehicle intruder. The method of ANFIS (adaptive neuro fuzzy inference system) was applied to the data resulting from these measurements. The ANFIS process for variable selection was implemented in order to detect the predominant variables affecting the prediction of agent speed relative to intruder. This process includes several ways to discover a subset of the total set of recorded parameters, showing good predictive capability. The ANFIS network was used to perform a variable search. Then, it was used to determine how 9 parameters (Intruder Front sensors active (boolean), Intruder Rear sensors active (boolean), Agent Front sensors active (boolean), Agent Rear sensors active (boolean), RSSI signal intensity/strength (integer), Elapsed time (in seconds), Distance between Agent and Intruder (m), Angle of Agent relative to Intruder (angle between vehicles °), Altitude difference between Agent and Intruder (m)) influence prediction of agent speed relative to intruder. The results indicated that distance between Vehicle agent and Vehicle intruder (m) and angle of Vehicle agent relative to Vehicle Intruder (angle between vehicles °) is the most influential parameters to Vehicle agent speed relative to Vehicle intruder.

Shallow and deep orthographies in Hebrew: the role of vowelization in reading development for unvowelized scripts.

PubMed

Schiff, Rachel

2012-12-01

The present study explored the speed, accuracy, and reading comprehension of vowelized versus unvowelized scripts among 126 native Hebrew speaking children in second, fourth, and sixth grades. Findings indicated that second graders read and comprehended vowelized scripts significantly more accurately and more quickly than unvowelized scripts, whereas among fourth and sixth graders reading of unvowelized scripts developed to a greater degree than the reading of vowelized scripts. An analysis of the mediation effect for children's mastery of vowelized reading speed and accuracy on their mastery of unvowelized reading speed and comprehension revealed that in second grade, reading accuracy of vowelized words mediated the reading speed and comprehension of unvowelized scripts. In the fourth grade, accuracy in reading both vowelized and unvowelized words mediated the reading speed and comprehension of unvowelized scripts. By sixth grade, accuracy in reading vowelized words offered no mediating effect, either on reading speed or comprehension of unvowelized scripts. The current outcomes thus suggest that young Hebrew readers undergo a scaffolding process, where vowelization serves as the foundation for building initial reading abilities and is essential for successful and meaningful decoding of unvowelized scripts.

Social strain and executive function across the lifespan: The dark (and light) sides of social engagement

PubMed Central

Tun, Patricia A.; Miller-Martinez, Dana; Lachman, Margie E.; Seeman, Teresa

2012-01-01

We investigated how the association between social strain and cognitive efficiency varies with task demands across adulthood, from latencies on simpler speeded tasks to tests involving executive function. Participants (N= 3280) were drawn from the MIDUS survey, a large, diverse national sample of adults who completed cognitive tests including speeded task-switching (Tun & Lachman, 2008). After controlling for demographic and health variables, we found that higher levels of reported social strain were associated with slower processing speed, particularly for the complex task-switching test relative to simpler speeded tests. Effects of strain were greatest for those with the lowest general cognitive ability. Moreover, those with very high levels of social strain but low levels of social support gave the poorest task-switching performance. These findings provide further evidence for the complex relationship between the social environment and cognition across adulthood, particularly the association between efficiency of executive functions and negative social interactions. PMID:22873285

Gait speed using powered robotic exoskeletons after spinal cord injury: a systematic review and correlational study.

PubMed

Louie, Dennis R; Eng, Janice J; Lam, Tania

2015-10-14

Powered robotic exoskeletons are an emerging technology of wearable orthoses that can be used as an assistive device to enable non-ambulatory individuals with spinal cord injury (SCI) to walk, or as a rehabilitation tool to improve walking ability in ambulatory individuals with SCI. No studies to date have systematically reviewed the literature on the efficacy of powered exoskeletons on restoring walking function. Our objective was to systematically review the literature to determine the gait speed attained by individuals with SCI when using a powered exoskeleton to walk, factors influencing this speed, and characteristics of studies involving a powered exoskeleton (e.g. inclusion criteria, screening, and training processes). A systematic search in computerized databases was conducted to identify articles that reported on walking outcomes when using a powered exoskeleton. Individual gait speed data from each study was extracted. Pearson correlations were performed between gait speed and 1) age, 2) years post-injury, 3) injury level, and 4) number of training sessions. Fifteen articles met inclusion criteria, 14 of which investigated the powered exoskeleton as an assistive device for non-ambulatory individuals and one which used it as a training intervention for ambulatory individuals with SCI. The mean gait speed attained by non-ambulatory participants (n = 84) while wearing a powered exoskeleton was 0.26 m/s, with the majority having a thoracic-level motor-complete injury. Twelve articles reported individual data for the non-ambulatory participants, from which a positive correlation was found between gait speed and 1) age (r = 0.27, 95 % CI 0.02-0.48, p = 0.03, 63 participants), 2) injury level (r = 0.27, 95 % CI 0.02-0.48, p = 0.03, 63 participants), and 3) training sessions (r = 0.41, 95 % CI 0.16-0.61, p = 0.002, 55 participants). In conclusion, powered exoskeletons can provide non-ambulatory individuals with thoracic-level motor-complete SCI the ability to walk at modest speeds. This speed is related to level of injury as well as training time.

Hatha Yoga Practice Improves Attention and Processing Speed in Older Adults: Results from an 8-Week Randomized Control Trial.

PubMed

Gothe, Neha P; Kramer, Arthur F; McAuley, Edward

2017-01-01

Age-related cognitive decline is well documented across various aspects of cognitive function, including attention and processing speed, and lifestyle behaviors such as physical activity play an important role in preventing cognitive decline and maintaining or even improving cognitive function. The purpose of this study was to evaluate the effects of an 8-week Hatha yoga intervention on attention and processing speed among older adults. Participants (n = 118; mean age, 62 ± 5.59) were randomly assigned to an 8-week Hatha yoga group or a stretching control group and completed cognitive assessments-Attention Network Task, Trail Making Test parts A and B, and Pattern Comparison Test-at baseline and after the 8-week intervention. Analyses of covariance revealed significantly faster reaction times for the yoga group on the Attention Network Task's neutral, congruent, and incongruent conditions (p ≤ 0.04). The yoga intervention also improved participants' visuospatial and perceptual processing on the Trail Making Test part B (p = 0.002) and pattern comparison (p < 0.001) tests. These results suggest that yoga practice that includes postures, breathing, and meditative exercises lead to improved attentional and information processing abilities. Although the underlying mechanisms remain largely speculative, more systematic trials are needed to explore the extent of cognitive benefits and their neurobiological mechanisms.

Software Accelerates Computing Time for Complex Math

NASA Technical Reports Server (NTRS)

2014-01-01

Ames Research Center awarded Newark, Delaware-based EM Photonics Inc. SBIR funding to utilize graphic processing unit (GPU) technology- traditionally used for computer video games-to develop high-computing software called CULA. The software gives users the ability to run complex algorithms on personal computers with greater speed. As a result of the NASA collaboration, the number of employees at the company has increased 10 percent.

Individual Differences in Time Estimation Related to Cognitive Ability, Speed of Information Processing and Working Memory

ERIC Educational Resources Information Center

Fink, A.; Neubauer, A. C.

2005-01-01

In experimental time estimation research, it has consistently been found that the more a person is engaged in some kind of demanding cognitive activity within a given period of time, the more experienced duration of this time interval decreases. However, the role of individual differences has been largely ignored in this field of research. In a…

Reading Development in an Orthographically Regular Language: Effects of Length, Frequency, Lexicality and Global Processing Ability

ERIC Educational Resources Information Center

Zoccolotti, Pierluigi; De Luca, Maria; Di Filippo, Gloria; Judica, Anna; Martelli, Marialuisa

2009-01-01

The acquisition of reading skill was studied in 503 Italian children in first to eighth grade using a task that required reading of lists of words and non-words. Analysis of the metric characteristics of the measures indicated that reading speed but not accuracy was normally distributed across all ages considered. The role of specific effects…

Toward a research-based assessment of dyslexia: using cognitive measures to identify reading disabilities.

PubMed

Bell, Sherry Mee; McCallum, R Steve; Cox, Elizabeth A

2003-01-01

One hundred five participants from a random sample of elementary and middle school children completed measures of reading achievement and cognitive abilities presumed, based on a synthesis of current dyslexia research, to underlie reading. Factor analyses of these cognitive variables (including auditory processing, phonological awareness, short-term auditory memory, visual memory, rapid automatized naming, and visual processing speed) produced three empirically and theoretically derived factors (auditory processing, visual processing/speed, and memory), each of which contributed to the prediction of reading and spelling skills. Factor scores from the three factors combined predicted 85% of the variance associated with letter/sight word naming, 70% of the variance associated with reading comprehension, 73% for spelling, and 61% for phonetic decoding. The auditory processing factor was the strongest predictor, accounting for 27% to 43% of the variance across the different achievement areas. The results provide practitioner and researcher with theoretical and empirical support for the inclusion of measures of the three factors, in addition to specific measures of reading achievement, in a standardized assessment of dyslexia. Guidelines for a thorough, research-based assessment are provided.

Speed kills: ineffective avian escape responses to oncoming vehicles

PubMed Central

DeVault, Travis L.; Blackwell, Bradley F.; Seamans, Thomas W.; Lima, Steven L.; Fernández-Juricic, Esteban

2015-01-01

Animal–vehicle collisions cause high levels of vertebrate mortality worldwide, and what goes wrong when animals fail to escape and ultimately collide with vehicles is not well understood. We investigated alert and escape behaviours of captive brown-headed cowbirds (Molothrus ater) in response to virtual vehicle approaches of different sizes and at speeds ranging from 60 to 360 km h−1. Alert and flight initiation distances remained similar across vehicle speeds, and accordingly, alert and flight initiation times decreased at higher vehicle speeds. Thus, avoidance behaviours in cowbirds appeared to be based on distance rather than time available for escape, particularly at 60–150 km h−1; however, at higher speeds (more than or equal to 180 km h−1) no trend in response behaviour was discernible. As vehicle speed increased, cowbirds did not have enough time to assess the approaching vehicle, and cowbirds generally did not initiate flight with enough time to avoid collision when vehicle speed exceeded 120 km h−1. Although potentially effective for evading predators, the decision-making process used by cowbirds in our study appears maladaptive in the context of avoiding fast-moving vehicles. Our methodological approach and findings provide a framework to assess how novel management strategies could affect escape rules, and the sensory and cognitive abilities animals use to avoid vehicle collisions. PMID:25567648

Blood Glucose, Diet-Based Glycemic Load and Cognitive Aging Among Dementia-Free Older Adults

PubMed Central

Andel, Ross; McEvoy, Cathy; Dahl Aslan, Anna K.; Finkel, Deborah; Pedersen, Nancy L.

2015-01-01

Background. Although evidence indicates that Type II Diabetes is related to abnormal brain aging, the influence of elevated blood glucose on long-term cognitive change is unclear. In addition, the relationship between diet-based glycemic load and cognitive aging has not been extensively studied. The focus of this study was to investigate the influence of diet-based glycemic load and blood glucose on cognitive aging in older adults followed for up to 16 years. Methods. Eight-hundred and thirty-eight cognitively healthy adults aged ≥50 years (M = 63.1, SD = 8.3) from the Swedish Adoption/Twin Study of Aging were studied. Mixed effects growth models were utilized to assess overall performance and change in general cognitive functioning, perceptual speed, memory, verbal ability, and spatial ability as a function of baseline blood glucose and diet-based glycemic load. Results. High blood glucose was related to poorer overall performance on perceptual speed as well as greater rates of decline in general cognitive ability, perceptual speed, verbal ability, and spatial ability. Diet-based glycemic load was related to poorer overall performance in perceptual speed and spatial ability. Conclusion. Diet-based glycemic load and, in particular, elevated blood glucose appear important for cognitive performance/cognitive aging. Blood glucose control (perhaps through low glycemic load diets) may be an important target in the detection and prevention of age-related cognitive decline. PMID:25149688

Do mental speed and musical abilities interact?

PubMed

Gruhn, Wilfried; Galley, Niels; Kluth, Christine

2003-11-01

The relation between mental speed and musical ability was investigated. Seventeen subjects aged 3-7 years were divided into two subgroups: one (G1; n = 9) consisted of children who participated in an early childhood music program and who received informal musical guidance, but no special training; the other (G2; n = 8) consisted of highly talented young violin players who received intensive parental support and special training by daily deliberate practice. Mental and musical abilities of both groups were controlled by standardized tests (Kaufman's ABC and Gordon's PMMA) and compared with data taken from recordings of saccadic eye movement using online identification from an electrooculogram (EOG). Results of EOG measurement are referred to as "mental speed," which correlates highly with general mental abilities (intelligence). These results were compared with EOG scores taken from a larger sample of children of the same age range (n = 82) who received no music instruction. The grand average of their scores served as a reference line for mental speed, which is normally expected to be performed by an equivalent age group. Data in the two experimental groups did not differ statistically; however, all musically experienced children had a highly significant advantage in mental age (P <0.01) compared to the reference line of the normal population who did not exhibit any effect of training and practice. This indicates strong interaction between mental speed and music ability, which can be interpreted in terms of the expertise model and cognitive transfer effects.

An examination of iconic memory in children with autism spectrum disorders.

PubMed

McMorris, Carly A; Brown, Stephanie M; Bebko, James M

2013-08-01

Iconic memory is the ability to accurately recall a number of items after a very brief visual exposure. Previous research has examined these capabilities in typically developing (TD) children and individuals with intellectual disabilities (ID); however, there is limited research on these abilities in children with Autism Spectrum Disorders (ASD). Twenty-one TD and eighteen ASD children were presented with circular visual arrays of letters for 100 ms and were asked to recall as many letters as possible or a single letter that was cued for recall. Groups did not differ in the number of items recalled, the rate of information decay, or speed of information processing. These findings suggest that iconic memory is an intact skill for children with ASD, a result that has implications for subsequent information processing.

[Visual perception abilities in children with reading disabilities].

PubMed

Werpup-Stüwe, Lina; Petermann, Franz

2015-05-01

Visual perceptual abilities are increasingly being neglected in research concerning reading disabilities. This study measures the visual perceptual abilities of children with disabilities in reading. The visual perceptual abilities of 35 children with specific reading disorder and 30 controls were compared using the German version of the Developmental Test of Visual Perception – Adolescent and Adult (DTVP-A). 11 % of the children with specific reading disorder show clinically relevant performance on the DTVP-A. The perceptual abilities of both groups differ significantly. No significant group differences exist after controlling for general IQ or Perceptional Reasoning Index, but they do remain after controlling for Verbal Comprehension, Working Memory, and Processing Speed Index. The number of children with reading difficulties suffering from visual perceptual disorders has been underestimated. For this reason, visual perceptual abilities should always be tested when making a reading disorder diagnosis. Profiles of IQ-test results of children suffering from reading and visual perceptual disorders should be interpreted carefully.

Behavioural system identification of visual flight speed control in Drosophila melanogaster

PubMed Central

Rohrseitz, Nicola; Fry, Steven N.

2011-01-01

Behavioural control in many animals involves complex mechanisms with intricate sensory-motor feedback loops. Modelling allows functional aspects to be captured without relying on a description of the underlying complex, and often unknown, mechanisms. A wide range of engineering techniques are available for modelling, but their ability to describe time-continuous processes is rarely exploited to describe sensory-motor control mechanisms in biological systems. We performed a system identification of visual flight speed control in the fruitfly Drosophila, based on an extensive dataset of open-loop responses previously measured under free flight conditions. We identified a second-order under-damped control model with just six free parameters that well describes both the transient and steady-state characteristics of the open-loop data. We then used the identified control model to predict flight speed responses after a visual perturbation under closed-loop conditions and validated the model with behavioural measurements performed in free-flying flies under the same closed-loop conditions. Our system identification of the fruitfly's flight speed response uncovers the high-level control strategy of a fundamental flight control reflex without depending on assumptions about the underlying physiological mechanisms. The results are relevant for future investigations of the underlying neuromotor processing mechanisms, as well as for the design of biomimetic robots, such as micro-air vehicles. PMID:20525744

Behavioural system identification of visual flight speed control in Drosophila melanogaster.

PubMed

Rohrseitz, Nicola; Fry, Steven N

2011-02-06

Behavioural control in many animals involves complex mechanisms with intricate sensory-motor feedback loops. Modelling allows functional aspects to be captured without relying on a description of the underlying complex, and often unknown, mechanisms. A wide range of engineering techniques are available for modelling, but their ability to describe time-continuous processes is rarely exploited to describe sensory-motor control mechanisms in biological systems. We performed a system identification of visual flight speed control in the fruitfly Drosophila, based on an extensive dataset of open-loop responses previously measured under free flight conditions. We identified a second-order under-damped control model with just six free parameters that well describes both the transient and steady-state characteristics of the open-loop data. We then used the identified control model to predict flight speed responses after a visual perturbation under closed-loop conditions and validated the model with behavioural measurements performed in free-flying flies under the same closed-loop conditions. Our system identification of the fruitfly's flight speed response uncovers the high-level control strategy of a fundamental flight control reflex without depending on assumptions about the underlying physiological mechanisms. The results are relevant for future investigations of the underlying neuromotor processing mechanisms, as well as for the design of biomimetic robots, such as micro-air vehicles.

Within-Hemifield Competition in Early Visual Areas Limits the Ability to Track Multiple Objects with Attention

PubMed Central

Alvarez, George A.; Cavanagh, Patrick

2014-01-01

It is much easier to divide attention across the left and right visual hemifields than within the same visual hemifield. Here we investigate whether this benefit of dividing attention across separate visual fields is evident at early cortical processing stages. We measured the steady-state visual evoked potential, an oscillatory response of the visual cortex elicited by flickering stimuli, of moving targets and distractors while human observers performed a tracking task. The amplitude of responses at the target frequencies was larger than that of the distractor frequencies when participants tracked two targets in separate hemifields, indicating that attention can modulate early visual processing when it is divided across hemifields. However, these attentional modulations disappeared when both targets were tracked within the same hemifield. These effects were not due to differences in task performance, because accuracy was matched across the tracking conditions by adjusting target speed (with control conditions ruling out effects due to speed alone). To investigate later processing stages, we examined the P3 component over central-parietal scalp sites that was elicited by the test probe at the end of the trial. The P3 amplitude was larger for probes on targets than on distractors, regardless of whether attention was divided across or within a hemifield, indicating that these higher-level processes were not constrained by visual hemifield. These results suggest that modulating early processing stages enables more efficient target tracking, and that within-hemifield competition limits the ability to modulate multiple target representations within the hemifield maps of the early visual cortex. PMID:25164651

How vocabulary size in two languages relates to efficiency in spoken word recognition by young Spanish-English bilinguals

PubMed Central

Marchman, Virginia A.; Fernald, Anne; Hurtado, Nereyda

2010-01-01

Research using online comprehension measures with monolingual children shows that speed and accuracy of spoken word recognition are correlated with lexical development. Here we examined speech processing efficiency in relation to vocabulary development in bilingual children learning both Spanish and English (n=26; 2;6 yrs). Between-language associations were weak: vocabulary size in Spanish was uncorrelated with vocabulary in English, and children’s facility in online comprehension in Spanish was unrelated to their facility in English. Instead, efficiency of online processing in one language was significantly related to vocabulary size in that language, after controlling for processing speed and vocabulary size in the other language. These links between efficiency of lexical access and vocabulary knowledge in bilinguals parallel those previously reported for Spanish and English monolinguals, suggesting that children’s ability to abstract information from the input in building a working lexicon relates fundamentally to mechanisms underlying the construction of language. PMID:19726000

Processing changes across reading encounters.

PubMed

Levy, B A; Newell, S; Snyder, J; Timmins, K

1986-10-01

Five experiments examined changes in the processing of a text across reading encounters. Experiment 1 showed that reading speed increased systematically across encounters, with no loss in the extensiveness of analyses of the printed text, as indicated by the ability to detect nonword errors embedded within that passage. Experiment 2 replicated this improved reading fluency with experience and showed that it occurred even with typescript changes across trials, thus indicating that a primed visual operations explanation cannot account for the effect. The third and fourth experiments then extended the study of the familiarity effect to higher level processing, as indicated by the detection of word errors. Familiarity facilitated the detection of these violations at the syntactic-semantic levels. Finally, Experiment 5 showed that these higher level violations continued to be well detected over a series of reading encounters with the same text. The results indicate that prior experience improves reading speed, with no attenuation of analysis of the printed words or of the passage's message.

Investigation of speed estimation using single loop detectors.

DOT National Transportation Integrated Search

2008-05-15

The ability to collect or estimate accurate speed information is of great importance to a large number of : Intelligent Transportation Systems (ITS) applications. Estimating speeds from the widely used single : inductive loop sensor has been a diffic...

The role of neuropsychological performance in the relationship between chronic pain and functional physical impairment.

PubMed

Pulles, Wiesje L J A; Oosterman, Joukje M

2011-12-01

  In this study, the relationship between pain intensity, neuropsychological, and physical function in adult chronic pain patients was examined.   Thirty participants with chronic pain completed neuropsychological tests tapping mental processing speed, memory, and executive function. Pain intensity was measured with three visual analog scales and the Pain Rating Index of the McGill Pain Questionnaire. A grip strength test, the 6-minute walk test, the Unipedal Stance Test and the Lifting Low Test were administered in order to obtain a performance-based measure of physical capacity. Self-reported physical ability was assessed with the Disability Rating Index and the Short Form-36 Physical Functioning, and Role Physical scales. Psychosocial function was examined using the Mental Health and Role Emotional subscales of the Short Form-36.   The study was set in two outpatient physical therapy clinics in The Netherlands.   The analysis showed that a lower mental processing speed was related to a higher level of pain, as well as to a lower performance-based and self-reported physical functioning. In addition, both performance-based and self-reported physical function revealed an inverse correlation with pain intensity. Psychosocial function turned out to be an important mediator of the relationship between pain and self-reported, but not performance-based, physical function. Mental processing speed, on the other hand, was found to mediate the relationship between pain and performance-based physical functioning.   The results suggest that in chronic pain patients, mental processing speed mediates the relationship between pain and physical function. Wiley Periodicals, Inc.

Investigating Phonological Awareness and Naming Speed as Predictors of Reading in Arabic

ERIC Educational Resources Information Center

Tibi, Sana; Kirby, John R.

2018-01-01

Wolf and Bowers (1999) described a model in which phonological awareness (PA) and naming speed (NS) make independent contributions to reading ability. We tested this model in a sample of 201 Grade 3 Arabic-speaking children in Dubai, United Arab Emirates. Measures of general cognitive ability, vocabulary, PA, NS, word reading, and reading…

High speed automated microtomography of nuclear emulsions and recent application

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tioukov, V.; Aleksandrov, A.; Consiglio, L.

2015-12-31

The development of high-speed automatic scanning systems was the key-factor for massive and successful emulsions application for big neutrino experiments like OPERA. The emulsion detector simplicity, the unprecedented sub-micron spatial resolution and the unique ability to provide intrinsically 3-dimensional spatial information make it a perfect device for short-living particles study, where the event topology should be precisely reconstructed in a 10-100 um scale vertex region. Recently the exceptional technological progress in image processing and automation together with intensive R&D done by Italian and Japanese microscopy groups permit to increase the scanning speed to unbelievable few years ago m{sup 2}/day scalemore » and so greatly extend the range of the possible applications for emulsion-based detectors to other fields like: medical imaging, directional dark matter search, nuclear physics, geological and industrial applications.« less

Effects of Technology on Experienced Job Characteristics and Job Satisfaction.

DTIC Science & Technology

1980-07-01

Ability to discriminate between odors (sense of smell) 23. Ability to discriminate between salty , sour, sweet (sense of taste ) 24. Ability to remember...Ability to estimate speed Ability to estimate quality Sense of touch Sense of smell Sense of taste Cognitive .833 Ability to remember names Ability to

Numerical magnitude processing in abacus-trained children with superior mathematical ability: an EEG study*

PubMed Central

Huang, Jian; Du, Feng-lei; Yao, Yuan; Wan, Qun; Wang, Xiao-song; Chen, Fei-yan

2015-01-01

Distance effect has been regarded as the best established marker of basic numerical magnitude processes and is related to individual mathematical abilities. A larger behavioral distance effect is suggested to be concomitant with lower mathematical achievement in children. However, the relationship between distance effect and superior mathematical abilities is unclear. One could get superior mathematical abilities by acquiring the skill of abacus-based mental calculation (AMC), which can be used to solve calculation problems with exceptional speed and high accuracy. In the current study, we explore the relationship between distance effect and superior mathematical abilities by examining whether and how the AMC training modifies numerical magnitude processing. Thus, mathematical competencies were tested in 18 abacus-trained children (who accepted the AMC training) and 18 non-trained children. Electroencephalography (EEG) waveforms were recorded when these children executed numerical comparison tasks in both Arabic digit and dot array forms. We found that: (a) the abacus-trained group had superior mathematical abilities than their peers; (b) distance effects were found both in behavioral results and on EEG waveforms; (c) the distance effect size of the average amplitude on the late negative-going component was different between groups in the digit task, with a larger effect size for abacus-trained children; (d) both the behavioral and EEG distance effects were modulated by the notation. These results revealed that the neural substrates of magnitude processing were modified by AMC training, and suggested that the mechanism of the representation of numerical magnitude for children with superior mathematical abilities was different from their peers. In addition, the results provide evidence for a view of non-abstract numerical representation. PMID:26238541

Unstable behaviour of RPT when testing turbine characteristics in the laboratory

NASA Astrophysics Data System (ADS)

Nielsen, T. K.; Fjørtoft Svarstad, M.

2014-03-01

A reversible pump turbine is a machine that can operate in three modes of operation i.e. in pumping mode. in turbine mode and in phase compensating mode (idle speed). Reversible pump turbines have an increasing importance for regulation purposes for obtaining power balance in electric power systems. Especially in grids dominated by thermal energy. reversible pump turbines improve the overall power regulating ability. Increased use of renewables (wind-. wave- and tidal power plants) will utterly demand better regulation ability of the traditional water power systems. enhancing the use of reversible pump turbines. A reversible pump turbine is known for having incredible steep speed - flow characteristics. As the speed increases the flow decreases more than that of a Francis turbines with the same specific speed. The steep characteristics might cause severe stability problems in turbine mode of operation. Stability in idle speed is a necessity for phasing in the generator to the electric grid. In the design process of a power plant. system dynamic simulations must be performed in order to check the system stability. The turbine characteristics will have to be modelled with certain accuracy even before one knows the exact turbine design and have measured characteristics. A representation of the RPT characteristics for system dynamic simulation purposes is suggested and compared with measured characteristics. The model shows good agreement with RPT characteristics measured in The Waterpower Laboratory. Because of the S-shaped characteristics. there is a stability issue involved when measuring these characteristics. Without special measures. it is impossible to achieve stable conditions in certain operational points. The paper discusses the mechanism when using a throttle to achieve system stability. even if the turbine characteristics imply instability.

Impact of the Ability to Divide Attention on Reading Performance in Glaucoma.

PubMed

Swenor, Bonnielin K; Varadaraj, Varshini; Dave, Paulomi; West, Sheila K; Rubin, Gary S; Ramulu, Pradeep Y

2017-05-01

To determine if the ability to divide attention affects the relationship between glaucoma-related vision loss and reading speed. Better eye mean deviation (MD), contrast sensitivity (CS), and better-eye distance visual acuity (VA) were measured in 28 participants with glaucoma and 21 controls. Reading speeds were assessed using MNRead, IRest, and sustained silent reading tests (words per minute, wpm). The ability to divide attention was measured using the Brief Test of Attention (BTA; scored 0-10). Multivariable linear regression models were used to determine the relationship between visual factors and reading speeds. Effect modification by BTA score (low BTA: <7; high BTA: ≥7) was examined. Worse CS (per 0.1 log unit) was associated with slower maximum reading speed on MNRead test for participants with low BTA scores (β = -9 wpm; 95% confidence interval [CI]: -16, -2), but not for those with high BTA scores (β = -2 wpm; 95% CI: -6, +2). Similarly, for the IRest test, worse CS was associated with slower reading speeds (β = -12 wpm; 95% CI: -20, -4) among those with low, but not high BTA scores (β = -4 wpm; 95% CI: -10, +2). For the sustained silent reading test, glaucoma status (versus controls), worse visual field (VF) MD (per 5 dB), and worse CS were associated with 39%, 21%, and 19% slower reading speeds, respectively, for those with low BTA scores (P < 0.05), but these associations were not significant among those with high BTA scores (P > 0.1 for all). Decreased ability to divide attention, indicated by lower BTA scores, is associated with slower reading speeds in glaucoma with reduced CS and VF defects.

Impact of the Ability to Divide Attention on Reading Performance in Glaucoma

PubMed Central

Swenor, Bonnielin K.; Varadaraj, Varshini; Dave, Paulomi; West, Sheila K.; Rubin, Gary S.; Ramulu, Pradeep Y.

2017-01-01

Purpose To determine if the ability to divide attention affects the relationship between glaucoma-related vision loss and reading speed. Methods Better eye mean deviation (MD), contrast sensitivity (CS), and better-eye distance visual acuity (VA) were measured in 28 participants with glaucoma and 21 controls. Reading speeds were assessed using MNRead, IRest, and sustained silent reading tests (words per minute, wpm). The ability to divide attention was measured using the Brief Test of Attention (BTA; scored 0–10). Multivariable linear regression models were used to determine the relationship between visual factors and reading speeds. Effect modification by BTA score (low BTA: <7; high BTA: ≥7) was examined. Results Worse CS (per 0.1 log unit) was associated with slower maximum reading speed on MNRead test for participants with low BTA scores (β = −9 wpm; 95% confidence interval [CI]: −16, −2), but not for those with high BTA scores (β = −2 wpm; 95% CI: −6, +2). Similarly, for the IRest test, worse CS was associated with slower reading speeds (β = −12 wpm; 95% CI: −20, −4) among those with low, but not high BTA scores (β = −4 wpm; 95% CI: −10, +2). For the sustained silent reading test, glaucoma status (versus controls), worse visual field (VF) MD (per 5 dB), and worse CS were associated with 39%, 21%, and 19% slower reading speeds, respectively, for those with low BTA scores (P < 0.05), but these associations were not significant among those with high BTA scores (P > 0.1 for all). Conclusions Decreased ability to divide attention, indicated by lower BTA scores, is associated with slower reading speeds in glaucoma with reduced CS and VF defects. PMID:28460047

Speeding up biomolecular interactions by molecular sledding

DOE PAGES

Turkin, Alexander; Zhang, Lei; Marcozzi, Alessio; ...

2015-10-07

In numerous biological processes associations involve a protein with its binding partner, an event that is preceded by a diffusion-mediated search bringing the two partners together. Often hindered by crowding in biologically relevant environments, three-dimensional diffusion can be slow and result in long bimolecular association times. Moreover, the initial association step between two binding partners often represents a rate-limiting step in biotechnologically relevant reactions. We also demonstrate the practical use of an 11-a.a. DNA-interacting peptide derived from adenovirus to reduce the dimensionality of diffusional search processes and speed up associations between biological macromolecules. We functionalize binding partners with the peptidemore » and demonstrate that the ability of the peptide to one-dimensionally diffuse along DNA results in a 20-fold reduction in reaction time. We also show that modifying PCR primers with the peptide sled enables significant acceleration of standard PCR reactions.« less

Oral and Hand Movement Speeds are Associated with Expressive Language Ability in Children with Speech Sound Disorder

PubMed Central

Peter, Beate

2013-01-01

This study tested the hypothesis that children with speech sound disorder have generalized slowed motor speeds. It evaluated associations among oral and hand motor speeds and measures of speech (articulation and phonology) and language (receptive vocabulary, sentence comprehension, sentence imitation), in 11 children with moderate to severe SSD and 11 controls. Syllable durations from a syllable repetition task served as an estimate of maximal oral movement speed. In two imitation tasks, nonwords and clapped rhythms, unstressed vowel durations and quarter-note clap intervals served as estimates of oral and hand movement speed, respectively. Syllable durations were significantly correlated with vowel durations and hand clap intervals. Sentence imitation was correlated with all three timed movement measures. Clustering on syllable repetition durations produced three clusters that also differed in sentence imitation scores. Results are consistent with limited movement speeds across motor systems and SSD subtypes defined by motor speeds as a corollary of expressive language abilities. PMID:22411590

Selective Use of Optical Variables to Control Forward Speed

NASA Technical Reports Server (NTRS)

Johnson, Walter W.; Awe, Cynthia A.; Hart, Sandra G. (Technical Monitor)

1994-01-01

Previous work on the perception and control of simulated vehicle speed has examined the contributions of optical flow rate (angular visual speed) and texture, or edge rate (frequency of passing terrain objects or markings) on the perception and control of forward speed. However, these studies have not examined the ability to selectively use edge rate or flow rate. The two studies reported here show that subjects found it very difficult to arbitrarily direct attention to one or the other of these variables; but that the ability to selectively use these variables is linked to the visual contextual information about the relative validity (linkage with speed) of the two variables. The selectivity also resulted in different velocity adaptation levels for events in which flow rate and edge rate specified forward speed. Finally, the role of visual context in directing attention was further buttressed by the finding that the incorrect perception of changes in ground texture density tended to be coupled with incorrect perceptions of changes in forward speed.

Oral and hand movement speeds are associated with expressive language ability in children with speech sound disorder.

PubMed

Peter, Beate

2012-12-01

This study tested the hypothesis that children with speech sound disorder have generalized slowed motor speeds. It evaluated associations among oral and hand motor speeds and measures of speech (articulation and phonology) and language (receptive vocabulary, sentence comprehension, sentence imitation), in 11 children with moderate to severe SSD and 11 controls. Syllable durations from a syllable repetition task served as an estimate of maximal oral movement speed. In two imitation tasks, nonwords and clapped rhythms, unstressed vowel durations and quarter-note clap intervals served as estimates of oral and hand movement speed, respectively. Syllable durations were significantly correlated with vowel durations and hand clap intervals. Sentence imitation was correlated with all three timed movement measures. Clustering on syllable repetition durations produced three clusters that also differed in sentence imitation scores. Results are consistent with limited movement speeds across motor systems and SSD subtypes defined by motor speeds as a corollary of expressive language abilities.

The development of sentence interpretation: effects of perceptual, attentional and semantic interference.

PubMed

Leech, Robert; Aydelott, Jennifer; Symons, Germaine; Carnevale, Julia; Dick, Frederic

2007-11-01

How does the development and consolidation of perceptual, attentional, and higher cognitive abilities interact with language acquisition and processing? We explored children's (ages 5-17) and adults' (ages 18-51) comprehension of morphosyntactically varied sentences under several competing speech conditions that varied in the degree of attentional demands, auditory masking, and semantic interference. We also evaluated the relationship between subjects' syntactic comprehension and their word reading efficiency and general 'speed of processing'. We found that the interactions between perceptual and attentional processes and complex sentence interpretation changed considerably over the course of development. Perceptual masking of the speech signal had an early and lasting impact on comprehension, particularly for more complex sentence structures. In contrast, increased attentional demand in the absence of energetic auditory masking primarily affected younger children's comprehension of difficult sentence types. Finally, the predictability of syntactic comprehension abilities by external measures of development and expertise is contingent upon the perceptual, attentional, and semantic milieu in which language processing takes place.

Cognitive correlates of verbal memory and verbal fluency in schizophrenia, and differential effects of various clinical symptoms between male and female patients.

PubMed

Brébion, Gildas; Villalta-Gil, Victoria; Autonell, Jaume; Cervilla, Jorge; Dolz, Montserrat; Foix, Alexandrina; Haro, Josep Maria; Usall, Judith; Vilaplana, Miriam; Ochoa, Susana

2013-06-01

Impairment of higher cognitive functions in patients with schizophrenia might stem from perturbation of more basic functions, such as processing speed. Various clinical symptoms might affect cognitive efficiency as well. Notably, previous research has revealed the role of affective symptoms on memory performance in this population, and suggested sex-specific effects. We conducted a post-hoc analysis of an extensive neuropsychological study of 88 patients with schizophrenia. Regression analyses were conducted on verbal memory and verbal fluency data to investigate the contribution of semantic organisation and processing speed to performance. The role of negative and affective symptoms and of attention disorders in verbal memory and verbal fluency was investigated separately in male and female patients. Semantic clustering contributed to verbal recall, and a measure of reading speed contributed to verbal recall as well as to phonological and semantic fluency. Negative symptoms affected verbal recall and verbal fluency in the male patients, whereas attention disorders affected these abilities in the female patients. Furthermore, depression affected verbal recall in women, whereas anxiety affected it in men. These results confirm the association of processing speed with cognitive efficiency in patients with schizophrenia. They also confirm the previously observed sex-specific associations of depression and anxiety with memory performance in these patients, and suggest that negative symptoms and attention disorders likewise are related to cognitive efficiency differently in men and women. Copyright © 2013 Elsevier B.V. All rights reserved.

A Randomized Clinical Trial of Cognitive Enhancement Therapy for Adults with Autism Spectrum Disorders

DTIC Science & Technology

2013-10-01

changes in brain function have indicated significant increases in brain activity supporting theory of mind and emotion regulation abilities in...depicted in the scenarios; adults with ASD have previously shown hypoactivation in the temporo- parietal-junction theory of mind (ToM) network when...treatment MRI data have been collected with processing speed, perspective-taking, theory of mind , and emotion regulation fMRI measures on participants

Processing speed, attention, and working memory after treatment for medulloblastoma: an international, prospective, and longitudinal study.

PubMed

Palmer, Shawna L; Armstrong, Carol; Onar-Thomas, Arzu; Wu, Shengjie; Wallace, Dana; Bonner, Melanie J; Schreiber, Jane; Swain, Michelle; Chapieski, Lynn; Mabbott, Donald; Knight, Sarah; Boyle, Robyn; Gajjar, Amar

2013-10-01

The current study prospectively examined processing speed (PS), broad attention (BA), and working memory (WM) ability of patients diagnosed with medulloblastoma over a 5-year period. The study included 126 patients, ages 3 to 21 years at diagnosis, enrolled onto a collaborative protocol for medulloblastoma. Patients were treated with postsurgical risk-adapted craniospinal irradiation (n = 36 high risk [HR]; n = 90 average risk) followed by four cycles of high-dose chemotherapy with stem-cell support. Patients completed 509 neuropsychological evaluations using the Woodcock-Johnson Tests of Cognitive Abilities Third Edition (median of three observations per patient). Linear mixed effects models revealed that younger age at diagnosis, HR classification, and higher baseline scores were significantly associated with poorer outcomes in PS. Patients treated as HR and those with higher baseline scores are estimated to have less favorable outcomes in WM and BA over time. Parent education and marital status were significantly associated with BA and WM baseline scores but not change over time. Of the three key domains, PS was estimated to have the lowest scores at 5 years after diagnosis. Identifying cognitive domains most vulnerable to decline should guide researchers who are aiming to develop efficacious cognitive intervention and rehabilitation programs, thereby improving the quality of survivorship for the pediatric medulloblastoma population.

Cognitive functions in preschool children with specific language impairment.

PubMed

Reichenbach, Katrin; Bastian, Laura; Rohrbach, Saskia; Gross, Manfred; Sarrar, Lea

2016-07-01

A growing body of research has focused on executive functions in children with specific language impairment (SLI). However, results show limited convergence, particularly in preschool age. The current neuropsychological study compared performance of cognitive functions focused on executive components and working memory in preschool children with SLI to typically developing controls. Performance on the measures cognitive flexibility, inhibition, processing speed and phonological short-term memory was assessed. The monolingual, Caucasian study sample consisted of 30 children with SLI (Mage = 63.3 months, SD = 4.3 months) and 30 healthy controls (Mage = 62.2 months, SD = 3.7 months). Groups were matched for age and nonverbal IQ. Socioeconomic status of the participating families was included. Children with SLI had significantly poorer abilities of phonological short-term memory than matched controls. A tendency of poorer abilities in the SLI group was found for inhibition and processing speed. We confirmed phonological short-term memory to be a reliable marker of SLI in preschoolers. Our results do not give definite support for impaired executive function in SLI, possibly owing to limited sensitivity of test instruments in this age group. We argue for a standardization of executive function tests for research use. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Cognitive abilities and functional capacity in older adults: results from the modified Scales of Independent Behavior-Revised.

PubMed

Tan, Jing Ee; Hultsch, David F; Strauss, Esther

2009-04-01

The relationship between cognitive and functional abilities was examined in a sample of community-dwelling older adults. Self and informant (e.g., spouse) reports of participants' functional status were obtained on the modified Scales of Independent Behavior-Revised (mSIB-R). Participants also completed measures of processing speed, episodic memory, executive functioning, and verbal ability. Results showed that the mSIB-R correlated positively with cognitive variables. Hierarchical regression analyses suggested that each mSIB-R factor is predicted by somewhat different cognitive variables, after adjusting for demographic, health, and motor variables. This report-based measure was as accurate as a performance-based measure in classifying cognitive groups. Informant social/cognitive engagement and self physical/environment engagement factors showed the most promise in this regard. The findings reveal links between cognitive and functional abilities in a sample with varying degrees of cognitive impairment.

Associations of physical activity with driving-related cognitive abilities in older drivers: an exploratory study.

PubMed

Marmeleira, José; Ferreira, Inês; Melo, Filipe; Godinho, Mário

2012-10-01

The purpose of this study was to examine the associations between hysical activity and driving-related cognitive abilities of older drivers. Thirty-eight female and male drivers ages 61 to 81 years (M = 70.2, SD = 5.0) responded to the International Physical Activity Questionnaire and were assessed on a battery of neuropsychological tests, which included measures of visual attention, executive functioning, mental status, visuospatial ability, and memory. A higher amount of reported physical activity was significantly correlated with better scores on tests of visual processing speed and divided visual attention. Higher amounts of physical activity was significantly associated with a better composite score for visual attention, but its correlation with the composite score for executive functioning was not significant. These findings support the hypothesis that pzhysical activity is associated with preservation of specific driving-related cognitive abilities of older adults.

Epilepsy & IQ: the clinical utility of the Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) indices in the neuropsychological assessment of people with epilepsy.

PubMed

Baxendale, Sallie; McGrath, Katherine; Thompson, Pamela J

2014-01-01

We examined Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) General Ability Index (GAI) and Full Scale Intelligence Quotient (FSIQ) discrepancies in 100 epilepsy patients; 44% had a significant GAI > FSIQ discrepancy. GAI-FSIQ discrepancies were correlated with the number of antiepileptic drugs taken and duration of epilepsy. Individual antiepileptic drugs differentially interfere with the expression of underlying intellectual ability in this group. FSIQ may significantly underestimate levels of general intellectual ability in people with epilepsy. Inaccurate representations of FSIQ due to selective impairments in working memory and reduced processing speed obscure the contextual interpretation of performance on other neuropsychological tests, and subtle localizing and lateralizing signs may be missed as a result.

Accelerating phylogenetics computing on the desktop: experiments with executing UPGMA in programmable logic.

PubMed

Davis, J P; Akella, S; Waddell, P H

2004-01-01

Having greater computational power on the desktop for processing taxa data sets has been a dream of biologists/statisticians involved in phylogenetics data analysis. Many existing algorithms have been highly optimized-one example being Felsenstein's PHYLIP code, written in C, for UPGMA and neighbor joining algorithms. However, the ability to process more than a few tens of taxa in a reasonable amount of time using conventional computers has not yielded a satisfactory speedup in data processing, making it difficult for phylogenetics practitioners to quickly explore data sets-such as might be done from a laptop computer. We discuss the application of custom computing techniques to phylogenetics. In particular, we apply this technology to speed up UPGMA algorithm execution by a factor of a hundred, against that of PHYLIP code running on the same PC. We report on these experiments and discuss how custom computing techniques can be used to not only accelerate phylogenetics algorithm performance on the desktop, but also on larger, high-performance computing engines, thus enabling the high-speed processing of data sets involving thousands of taxa.

Efficacy of a Computer-Assisted Cognitive Rehabilitation Intervention in Relapsing-Remitting Multiple Sclerosis Patients: A Multicenter Randomized Controlled Trial

PubMed Central

Kosmidis, Mary H.; Zampakis, Petros; Malefaki, Sonia; Ntoskou, Katerina; Nousia, Anastasia; Bakirtzis, Christos; Papathanasopoulos, Panagiotis

2017-01-01

Cognitive impairment is frequently encountered in multiple sclerosis (MS) affecting between 40–65% of individuals, irrespective of disease duration and severity of physical disability. In the present multicenter randomized controlled trial, fifty-eight clinically stable RRMS patients with mild to moderate cognitive impairment and relatively low disability status were randomized to receive either computer-assisted (RehaCom) functional cognitive training with an emphasis on episodic memory, information processing speed/attention, and executive functions for 10 weeks (IG; n = 32) or standard clinical care (CG; n = 26). Outcome measures included a flexible comprehensive neuropsychological battery of tests sensitive to MS patient deficits and feedback regarding personal benefit gained from the intervention on four verbal questions. Only the IG group showed significant improvements in verbal and visuospatial episodic memory, processing speed/attention, and executive functioning from pre - to postassessment. Moreover, the improvement obtained on attention was retained over 6 months providing evidence on the long-term benefits of this intervention. Group by time interactions revealed significant improvements in composite cognitive domain scores in the IG relative to the demographically and clinically matched CG for verbal episodic memory, processing speed, verbal fluency, and attention. Treated patients rated the intervention positively and were more confident about their cognitive abilities following treatment. PMID:29463950

Co-morbid depressive disorder is associated with better neurocognitive performance in first episode schizophrenia spectrum.

PubMed

Herniman, Sarah E; Cotton, Sue M; Killackey, Eóin; Hester, Robert; Allott, Kelly A

2018-03-15

Both major depressive disorder (MDD) and first episode schizophrenia spectrum (FES) are associated with significant neurocognitive deficits. However, it remains unclear whether the neurocognitive deficits in individuals with FES are more severe if there is comorbid depressive disorder. The aim of this study was to compare the neurocognitive profiles between those with and without full-threshold depressive disorder in FES. This study involved secondary analysis of baseline data from a randomized controlled trial of vocational intervention for young people with first-episode psychosis (N = 82; age range: 15-25 years). Those with full-threshold depressive disorder (n = 24) had significantly better information processing speed than those without full-threshold depressive disorder. Severity of depressive symptoms was also associated with better information processing speed. In additional to the cross-sectional design, limitations of this study include the absence of assessing insight as a potential mediator. After the first psychotic episode, it could be speculated that those with better information processing speed may be more likely to develop full-threshold depressive disorder, as their ability to efficiently process information may allow them to be more aware of their situations and environments, and consequently to have greater insight into the devastating consequences of FES. Such novel findings support the examination of full-threshold depressive disorder in relation to neurocognitive performance across illness phases in future work. Copyright © 2018 Elsevier B.V. All rights reserved.

The ACTIVE conceptual framework as a structural equation model

PubMed Central

Gross, Alden L.; Payne, Brennan R.; Casanova, Ramon; Davoudzadeh, Pega; Dzierzewski, Joseph M.; Farias, Sarah; Giovannetti, Tania; Ip, Edward H.; Marsiske, Michael; Rebok, George W.; Schaie, K. Warner; Thomas, Kelsey; Willis, Sherry; Jones, Richard N.

2018-01-01

Background/Study Context Conceptual frameworks are analytic models at a high level of abstraction. Their operationalization can inform randomized trial design and sample size considerations. Methods The Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) conceptual framework was empirically tested using structural equation modeling (N=2,802). ACTIVE was guided by a conceptual framework for cognitive training in which proximal cognitive abilities (memory, inductive reasoning, speed of processing) mediate treatment-related improvement in primary outcomes (everyday problem-solving, difficulty with activities of daily living, everyday speed, driving difficulty), which in turn lead to improved secondary outcomes (health-related quality of life, health service utilization, mobility). Measurement models for each proximal, primary, and secondary outcome were developed and tested using baseline data. Each construct was then combined in one model to evaluate fit (RMSEA, CFI, normalized residuals of each indicator). To expand the conceptual model and potentially inform future trials, evidence of modification of structural model parameters was evaluated by age, years of education, sex, race, and self-rated health status. Results Preconceived measurement models for memory, reasoning, speed of processing, everyday problem-solving, instrumental activities of daily living (IADL) difficulty, everyday speed, driving difficulty, and health-related quality of life each fit well to the data (all RMSEA < .05; all CFI > .95). Fit of the full model was excellent (RMSEA = .038; CFI = .924). In contrast with previous findings from ACTIVE regarding who benefits from training, interaction testing revealed associations between proximal abilities and primary outcomes are stronger on average by nonwhite race, worse health, older age, and less education (p < .005). Conclusions Empirical data confirm the hypothesized ACTIVE conceptual model. Findings suggest that the types of people who show intervention effects on cognitive performance potentially may be different from those with the greatest chance of transfer to real-world activities. PMID:29303475

The contributions of balance to gait capacity and motor function in chronic stroke.

PubMed

Lee, Kyoung Bo; Lim, Seong Hoon; Kim, Young Dong; Yang, Byung Il; Kim, Kyung Hoon; Lee, Kang Sung; Kim, Eun Ja; Hwang, Byong Yong

2016-06-01

[Purpose] The aim of this study was to identify the contributions of balance to gait and motor function in chronic stroke. [Subjects and Methods] Twenty-three outpatients participated in a cross-sectional assessment. Gait ability was assessed using the functional ambulation category, self-paced 10-m walking speed, and fastest 10-m walking speed. Standing balance and trunk control measures included the Berg Balance Scale and the Trunk Impairment Scale. Univariate and multivariate regression analyses were performed. [Results] Balance was the best predictor of the FAC, self-paced walking speed, and fastest walking speed, accounting for 57% to 61% of the variances. Additionally, the total score of TIS was the only predictor of the motor function of the lower limbs and the dynamic balance of TIS was a predictor of the motor function of the upper limbs, accounting for 41% and 29% of the variance, respectively. [Conclusion] This study demonstrated the relative contribution of standing balance and trunk balance to gait ability and motor function. They show that balance has a high power of explanation of gait ability and that trunk balance is a determinant of motor function rather than gait ability.

The contributions of balance to gait capacity and motor function in chronic stroke

PubMed Central

Lee, Kyoung Bo; Lim, Seong Hoon; Kim, Young Dong; Yang, Byung Il; Kim, Kyung Hoon; Lee, Kang Sung; Kim, Eun Ja; Hwang, Byong Yong

2016-01-01

[Purpose] The aim of this study was to identify the contributions of balance to gait and motor function in chronic stroke. [Subjects and Methods] Twenty-three outpatients participated in a cross-sectional assessment. Gait ability was assessed using the functional ambulation category, self-paced 10-m walking speed, and fastest 10-m walking speed. Standing balance and trunk control measures included the Berg Balance Scale and the Trunk Impairment Scale. Univariate and multivariate regression analyses were performed. [Results] Balance was the best predictor of the FAC, self-paced walking speed, and fastest walking speed, accounting for 57% to 61% of the variances. Additionally, the total score of TIS was the only predictor of the motor function of the lower limbs and the dynamic balance of TIS was a predictor of the motor function of the upper limbs, accounting for 41% and 29% of the variance, respectively. [Conclusion] This study demonstrated the relative contribution of standing balance and trunk balance to gait ability and motor function. They show that balance has a high power of explanation of gait ability and that trunk balance is a determinant of motor function rather than gait ability. PMID:27390395

Improving Sprint Performance in Soccer: Effectiveness of Jump Squat and Olympic Push Press Exercises

PubMed Central

Loturco, Irineu; Pereira, Lucas Adriano; Kobal, Ronaldo; Maldonado, Thiago; Piazzi, Alessandro Fromer; Bottino, Altamiro; Kitamura, Katia; Cal Abad, Cesar Cavinato; de Arruda, Miguel; Nakamura, Fabio Yuzo

2016-01-01

Training at the optimum power load (OPL) is an effective way to improve neuromuscular abilities of highly trained athletes. The purpose of this study was to test the effects of training using the jump squat (JS) or Olympic push-press (OPP) exercises at the OPL during a short-term preseason on speed-power related abilities in high-level under-20 soccer players. The players were divided into two training groups: JS group (JSG) and OPP group (OPPG). Both groups undertook 12 power-oriented sessions, using solely JS or OPP exercises. Pre- and post-6 weeks of training, athletes performed squat jump (SJ), countermovement jump (CMJ), sprinting speed (5, 10, 20 and 30 m), change of direction (COD) and speed tests. To calculate the transfer effect coefficient (TEC) between JS and MPP OPP and the speed in 5, 10, 20, and 30 m, the ratio between the result gain (effect size [ES]) in the untrained exercise and result gain in the trained exercise was calculated. Magnitude based inference and ES were used to test the meaningful effects. The TEC between JS and VEL 5, 10, 20, and 30 m ranged from 0.77 to 1.29, while the only TEC which could be calculated between OPP and VEL 5 was rather low (0.2). In addition, the training effects of JS on jumping and speed related abilities were superior (ES ranging from small to large) to those caused by OPP (trivial ES). To conclude, the JS exercise is superior to the OPP for improving speed-power abilities in elite young soccer players. PMID:27100085

Improving Sprint Performance in Soccer: Effectiveness of Jump Squat and Olympic Push Press Exercises.

PubMed

Loturco, Irineu; Pereira, Lucas Adriano; Kobal, Ronaldo; Maldonado, Thiago; Piazzi, Alessandro Fromer; Bottino, Altamiro; Kitamura, Katia; Cal Abad, Cesar Cavinato; de Arruda, Miguel; Nakamura, Fabio Yuzo

2016-01-01

Training at the optimum power load (OPL) is an effective way to improve neuromuscular abilities of highly trained athletes. The purpose of this study was to test the effects of training using the jump squat (JS) or Olympic push-press (OPP) exercises at the OPL during a short-term preseason on speed-power related abilities in high-level under-20 soccer players. The players were divided into two training groups: JS group (JSG) and OPP group (OPPG). Both groups undertook 12 power-oriented sessions, using solely JS or OPP exercises. Pre- and post-6 weeks of training, athletes performed squat jump (SJ), countermovement jump (CMJ), sprinting speed (5, 10, 20 and 30 m), change of direction (COD) and speed tests. To calculate the transfer effect coefficient (TEC) between JS and MPP OPP and the speed in 5, 10, 20, and 30 m, the ratio between the result gain (effect size [ES]) in the untrained exercise and result gain in the trained exercise was calculated. Magnitude based inference and ES were used to test the meaningful effects. The TEC between JS and VEL 5, 10, 20, and 30 m ranged from 0.77 to 1.29, while the only TEC which could be calculated between OPP and VEL 5 was rather low (0.2). In addition, the training effects of JS on jumping and speed related abilities were superior (ES ranging from small to large) to those caused by OPP (trivial ES). To conclude, the JS exercise is superior to the OPP for improving speed-power abilities in elite young soccer players.

Wavelet-space correlation imaging for high-speed MRI without motion monitoring or data segmentation.

PubMed

Li, Yu; Wang, Hui; Tkach, Jean; Roach, David; Woods, Jason; Dumoulin, Charles

2015-12-01

This study aims to (i) develop a new high-speed MRI approach by implementing correlation imaging in wavelet-space, and (ii) demonstrate the ability of wavelet-space correlation imaging to image human anatomy with involuntary or physiological motion. Correlation imaging is a high-speed MRI framework in which image reconstruction relies on quantification of data correlation. The presented work integrates correlation imaging with a wavelet transform technique developed originally in the field of signal and image processing. This provides a new high-speed MRI approach to motion-free data collection without motion monitoring or data segmentation. The new approach, called "wavelet-space correlation imaging", is investigated in brain imaging with involuntary motion and chest imaging with free-breathing. Wavelet-space correlation imaging can exceed the speed limit of conventional parallel imaging methods. Using this approach with high acceleration factors (6 for brain MRI, 16 for cardiac MRI, and 8 for lung MRI), motion-free images can be generated in static brain MRI with involuntary motion and nonsegmented dynamic cardiac/lung MRI with free-breathing. Wavelet-space correlation imaging enables high-speed MRI in the presence of involuntary motion or physiological dynamics without motion monitoring or data segmentation. © 2014 Wiley Periodicals, Inc.

Wavelet-space Correlation Imaging for High-speed MRI without Motion Monitoring or Data Segmentation

PubMed Central

Li, Yu; Wang, Hui; Tkach, Jean; Roach, David; Woods, Jason; Dumoulin, Charles

2014-01-01

Purpose This study aims to 1) develop a new high-speed MRI approach by implementing correlation imaging in wavelet-space, and 2) demonstrate the ability of wavelet-space correlation imaging to image human anatomy with involuntary or physiological motion. Methods Correlation imaging is a high-speed MRI framework in which image reconstruction relies on quantification of data correlation. The presented work integrates correlation imaging with a wavelet transform technique developed originally in the field of signal and image processing. This provides a new high-speed MRI approach to motion-free data collection without motion monitoring or data segmentation. The new approach, called “wavelet-space correlation imaging”, is investigated in brain imaging with involuntary motion and chest imaging with free-breathing. Results Wavelet-space correlation imaging can exceed the speed limit of conventional parallel imaging methods. Using this approach with high acceleration factors (6 for brain MRI, 16 for cardiac MRI and 8 for lung MRI), motion-free images can be generated in static brain MRI with involuntary motion and nonsegmented dynamic cardiac/lung MRI with free-breathing. Conclusion Wavelet-space correlation imaging enables high-speed MRI in the presence of involuntary motion or physiological dynamics without motion monitoring or data segmentation. PMID:25470230

A Diffusion Model Analysis of Magnitude Comparison in Children with and without Dyscalculia: Care of Response and Ability Are Related to Both Mathematical Achievement and Stimuli.

PubMed

Szardenings, Carsten; Kuhn, Jörg-Tobias; Ranger, Jochen; Holling, Heinz

2017-01-01

The respective roles of the approximate number system (ANS) and an access deficit (AD) in developmental dyscalculia (DD) are not well-known. Most studies rely on response times (RTs) or accuracy (error rates) separately. We analyzed the results of two samples of elementary school children in symbolic magnitude comparison (MC) and non-symbolic MC using a diffusion model. This approach uses the joint distribution of both RTs and accuracy in order to synthesize measures closer to ability and response caution or response conservatism. The latter can be understood in the context of the speed-accuracy tradeoff: It expresses how much a subject trades in speed for improved accuracy. We found significant effects of DD on both ability (negative) and response caution (positive) in MC tasks and a negative interaction of DD with symbolic task material on ability. These results support that DD subjects suffer from both an impaired ANS and an AD and in particular support that slower RTs of children with DD are indeed related to impaired processing of numerical information. An interaction effect of symbolic task material and DD (low mathematical ability) on response caution could not be refuted. However, in a sample more representative of the general population we found a negative association of mathematical ability and response caution in symbolic but not in non-symbolic task material. The observed differences in response behavior highlight the importance of accounting for response caution in the analysis of MC tasks. The results as a whole present a good example of the benefits of a diffusion model analysis.

A Diffusion Model Analysis of Magnitude Comparison in Children with and without Dyscalculia: Care of Response and Ability Are Related to Both Mathematical Achievement and Stimuli

PubMed Central

Szardenings, Carsten; Kuhn, Jörg-Tobias; Ranger, Jochen; Holling, Heinz

2018-01-01

The respective roles of the approximate number system (ANS) and an access deficit (AD) in developmental dyscalculia (DD) are not well-known. Most studies rely on response times (RTs) or accuracy (error rates) separately. We analyzed the results of two samples of elementary school children in symbolic magnitude comparison (MC) and non-symbolic MC using a diffusion model. This approach uses the joint distribution of both RTs and accuracy in order to synthesize measures closer to ability and response caution or response conservatism. The latter can be understood in the context of the speed-accuracy tradeoff: It expresses how much a subject trades in speed for improved accuracy. We found significant effects of DD on both ability (negative) and response caution (positive) in MC tasks and a negative interaction of DD with symbolic task material on ability. These results support that DD subjects suffer from both an impaired ANS and an AD and in particular support that slower RTs of children with DD are indeed related to impaired processing of numerical information. An interaction effect of symbolic task material and DD (low mathematical ability) on response caution could not be refuted. However, in a sample more representative of the general population we found a negative association of mathematical ability and response caution in symbolic but not in non-symbolic task material. The observed differences in response behavior highlight the importance of accounting for response caution in the analysis of MC tasks. The results as a whole present a good example of the benefits of a diffusion model analysis. PMID:29379450

Contextual analysis of fluid intelligence.

PubMed

Salthouse, Timothy A; Pink, Jeffrey E; Tucker-Drob, Elliot M

2008-01-01

The nature of fluid intelligence was investigated by identifying variables that were, and were not, significantly related to this construct. Relevant information was obtained from three sources: re-analyses of data from previous studies, a study in which 791 adults performed storage-plus-processing working memory tasks, and a study in which 236 adults performed a variety of working memory, updating, and cognitive control tasks. The results suggest that fluid intelligence represents a broad individual difference dimension contributing to diverse types of controlled or effortful processing. The analyses also revealed that very few of the age-related effects on the target variables were statistically independent of effects on established cognitive abilities, which suggests most of the age-related influences on a wide variety of cognitive control variables overlap with age-related influences on cognitive abilities such as fluid intelligence, episodic memory, and perceptual speed.

Bioprinting towards Physiologically Relevant Tissue Models for Pharmaceutics.

PubMed

Peng, Weijie; Unutmaz, Derya; Ozbolat, Ibrahim T

2016-09-01

Improving the ability to predict the efficacy and toxicity of drug candidates earlier in the drug discovery process will speed up the introduction of new drugs into clinics. 3D in vitro systems have significantly advanced the drug screening process as 3D tissue models can closely mimic native tissues and, in some cases, the physiological response to drugs. Among various in vitro systems, bioprinting is a highly promising technology possessing several advantages such as tailored microarchitecture, high-throughput capability, coculture ability, and low risk of cross-contamination. In this opinion article, we discuss the currently available tissue models in pharmaceutics along with their limitations and highlight the possibilities of bioprinting physiologically relevant tissue models, which hold great potential in drug testing, high-throughput screening, and disease modeling. Copyright © 2016 Elsevier Ltd. All rights reserved.

Response inhibition, preattentive processing, and sex difference in young children: an event-related potential study.

PubMed

Liu, Tongran; Xiao, Tong; Shi, Jiannong

2013-02-13

Response inhibition and preattentive processing are two important cognitive abilities for child development, and the current study adopted both behavioral and electrophysiological protocols to examine whether young children's response inhibition correlated with their preattentive processing. A Go/Nogo task was used to explore young children's response inhibition performances and an Oddball task with event-related potential recordings was used to measure their preattentive processing. The behavioral results showed that girls committed significantly fewer commission error rates, which showed that girls had stronger inhibition control abilities than boys. Girls also achieved higher d' scores in the Go/Nogo task, which indicated that they were more sensitive to the stimulus signals than boys. Although the electrophysiological results of preattentive processing did not show any sex differences, the correlation patterns between children's response inhibition and preattentive processing were different between these two groups: the neural response speed of preattentive processing (mismatch negativity peak latency) negatively correlated with girls' commission error rates and positively correlated with boys' correct hit rates. The current findings supported that the preattentive processing correlated with human inhibition control performances, and further showed that girls' better inhibition responses might be because of the influence of their preattentive processing.

Cognitive Predictors of Everyday Problem Solving across the Lifespan.

PubMed

Chen, Xi; Hertzog, Christopher; Park, Denise C

2017-01-01

An important aspect of successful aging is maintaining the ability to solve everyday problems encountered in daily life. The limited evidence today suggests that everyday problem solving ability increases from young adulthood to middle age, but decreases in older age. The present study examined age differences in the relative contributions of fluid and crystallized abilities to solving problems on the Everyday Problems Test (EPT). We hypothesized that due to diminishing fluid resources available with advanced age, crystallized knowledge would become increasingly important in predicting everyday problem solving with greater age. Two hundred and twenty-one healthy adults from the Dallas Lifespan Brain Study, aged 24-93 years, completed a cognitive battery that included measures of fluid ability (i.e., processing speed, working memory, inductive reasoning) and crystallized ability (i.e., multiple measures of vocabulary). These measures were used to predict performance on EPT. Everyday problem solving showed an increase in performance from young to early middle age, with performance beginning to decrease at about age of 50 years. As hypothesized, fluid ability was the primary predictor of performance on everyday problem solving for young adults, but with increasing age, crystallized ability became the dominant predictor. This study provides evidence that everyday problem solving ability differs with age, and, more importantly, that the processes underlying it differ with age as well. The findings indicate that older adults increasingly rely on knowledge to support everyday problem solving, whereas young adults rely almost exclusively on fluid intelligence. © 2017 S. Karger AG, Basel.

Linear hypergeneralization of learned dynamics across movement speeds reveals anisotropic, gain-encoding primitives for motor adaptation.

PubMed

Joiner, Wilsaan M; Ajayi, Obafunso; Sing, Gary C; Smith, Maurice A

2011-01-01

The ability to generalize learned motor actions to new contexts is a key feature of the motor system. For example, the ability to ride a bicycle or swing a racket is often first developed at lower speeds and later applied to faster velocities. A number of previous studies have examined the generalization of motor adaptation across movement directions and found that the learned adaptation decays in a pattern consistent with the existence of motor primitives that display narrow Gaussian tuning. However, few studies have examined the generalization of motor adaptation across movement speeds. Following adaptation to linear velocity-dependent dynamics during point-to-point reaching arm movements at one speed, we tested the ability of subjects to transfer this adaptation to short-duration higher-speed movements aimed at the same target. We found near-perfect linear extrapolation of the trained adaptation with respect to both the magnitude and the time course of the velocity profiles associated with the high-speed movements: a 69% increase in movement speed corresponded to a 74% extrapolation of the trained adaptation. The close match between the increase in movement speed and the corresponding increase in adaptation beyond what was trained indicates linear hypergeneralization. Computational modeling shows that this pattern of linear hypergeneralization across movement speeds is not compatible with previous models of adaptation in which motor primitives display isotropic Gaussian tuning of motor output around their preferred velocities. Instead, we show that this generalization pattern indicates that the primitives involved in the adaptation to viscous dynamics display anisotropic tuning in velocity space and encode the gain between motor output and motion state rather than motor output itself.

Heterogeneity in ADHD: Neurocognitive predictors of peer, family, and academic functioning.

PubMed

Kofler, Michael J; Sarver, Dustin E; Spiegel, Jamie A; Day, Taylor N; Harmon, Sherelle L; Wells, Erica L

2017-08-01

Childhood attention-deficit/hyperactivity disorder (ADHD) is associated with impairments in peer, family, and academic functioning. Although impairment is required for diagnosis, children with ADHD vary significantly in the areas in which they demonstrate clinically significant impairment. However, relatively little is known about the mechanisms and processes underlying these individual differences. The current study examined neurocognitive predictors of heterogeneity in peer, family, and academic functioning in a well-defined sample of 44 children with ADHD aged 8-13 years (M = 10.31, SD = 1.42; 31 boys, 13 girls; 81% Caucasian). Reliable change analysis indicated that 98% of the sample demonstrated objectively-defined impairment on at least one assessed outcome measure; 65% were impaired in two or all three areas of functioning. ADHD children with quantifiable deficits in academic success and family functioning performed worse on tests of working memory (d = 0.68 to 1.09), whereas children with impaired parent-reported social functioning demonstrated slower processing speed (d = 0.53). Dimensional analyses identified additional predictors of peer, family, and academic functioning. Working memory abilities were associated with individual differences in all three functional domains, processing speed predicted social functioning, and inhibitory control predicted family functioning. These results add to a growing literature implicating neurocognitive abilities not only in explaining behavioral differences between ADHD and non-ADHD groups, but also in the substantial heterogeneity in ecologically-valid functional outcomes associated with the disorder.

Experimental analysis of IMEP in a rotary combustion engine

NASA Technical Reports Server (NTRS)

Schock, H. J.; Rice, W. J.; Meng, P. R.

1981-01-01

A real time indicated mean effective pressure measurement system is described which is used to judge proposed improvements in cycle efficiency of a rotary combustion engine. This is the first self-contained instrument that is capable of making real time measurements of IMEP in a rotary engine. Previous methods used require data recording and later processing using a digital computer. The unique features of this instrumentation include its ability to measure IMEP on a cycle by cycle, real time basis and the elimination of the need to differentiate volume function in real time. Measurements at two engine speeds (2000 and 3000 rpm) and a full range of loads are presented, although the instrument was designed to operate to speeds of 9000 rpm.

Translations on USSR Science and Technology, Physical Sciences and Technology, Number 16

DTIC Science & Technology

1977-08-05

34INVESTIGATION OF SPLITTING OF LIGHT NUCLEI WITH HIGH-ENERGY y -RAYS WITH THE METHOD OF WILSON’S CHAMBER OPERATING IN POWERFUL BEAMS OF ELECTRONIC...boast high reliability, high speed, and extremely modest power requirements. Information oh the Screen Visual display devices greatly facilitate...area of application of these units Includes navigation, control of power systems, machine tools, and manufac- turing processes. Th» ^»abilities of

U.S. Supersonic Commercial Aircraft: Assessing NASA's High Speed Research Program

NASA Technical Reports Server (NTRS)

1997-01-01

The legislatively mandated objectives of the National Aeronautics and Space Administration (NASA) include "the improvement of the usefulness, performance, speed, safety, and efficiency of aeronautical and space vehicles" and "preservation of the United States' preeminent position in aeronautics and space through research and technology development related to associated manufacturing processes." Most of NASA's activities are focused on the space-related aspects of these objectives. However, NASA also conducts important work related to aeronautics. NASA's High Speed Research (HSR) Program is a focused technology development program intended to enable the commercial development of a high speed (i.e., supersonic) civil transport (HSCT). However, the HSR Program will not design or test a commercial airplane (i.e., an HSCT); it is industry's responsibility to use the results of the HSR Program to develop an HSCT. An HSCT would be a second generation aircraft with much better performance than first generation supersonic transports (i.e., the Concorde and the Soviet Tu-144). The HSR Program is a high risk effort: success requires overcoming many challenging technical problems involving the airframe, propulsion system, and integrated aircraft. The ability to overcome all of these problems to produce an affordable HSCT is far from certain. Phase I of the HSR Program was completed in fiscal year 1995; it produced critical information about the ability of an HSCT to satisfy environmental concerns (i-e., noise and engine emissions). Phase II (the final phase according to current plans) is scheduled for completion in 2002. Areas of primary emphasis are propulsion, airframe materials and structures, flight deck systems, aerodynamic performance, and systems integration.

Childhood Cognitive Ability and Age-Related Changes in Physical Capability From Midlife: Findings From a British Birth Cohort Study.

PubMed

Cooper, Rachel; Richards, Marcus; Kuh, Diana

2017-09-01

The aim of the study was to test the hypothesis that higher childhood cognitive ability is associated with reduced risk of decline in physical capability in late midlife. Participants were 1954 men and women from the Medical Research Council National Survey of Health and Development with complete data on cognitive ability at age of 15 years and measures of grip strength and chair rise speed at ages of 53 and 60 to 64 years. Using multinomial logistic regression, associations of childhood cognitive ability with categories of change in grip strength and chair rise speed (i.e., decline, stable high, stable low, reference) were investigated. Adjustments were made for potential confounders from early life and adult mediators including health behaviors, educational level, and cognitive ability at age of 53 years. Higher childhood cognitive scores were associated with reduced risks of decline in grip strength and chair rise speed, for example, the sex-adjusted relative-risk ratio of decline (versus reference) in grip strength per 1SD increase in childhood cognitive score was 0.82 (95% confidence interval = 0.73-0.92). Higher childhood cognitive scores were also associated with reduced risk of stable low and increased likelihood of stable high chair rise speed. These findings suggest that childhood cognitive ability may be related to decline in physical capability in late midlife. A number of life course pathways are implicated, including those linking childhood and adult cognitive ability. Future research aiming to identify new opportunities to prevent or minimize age-related declines in physical capability may benefit from considering the potential role of neurodevelopmental as well as neurodegenerative pathways.

Sustained multifocal attentional enhancement of stimulus processing in early visual areas predicts tracking performance.

PubMed

Störmer, Viola S; Winther, Gesche N; Li, Shu-Chen; Andersen, Søren K

2013-03-20

Keeping track of multiple moving objects is an essential ability of visual perception. However, the mechanisms underlying this ability are not well understood. We instructed human observers to track five or seven independent randomly moving target objects amid identical nontargets and recorded steady-state visual evoked potentials (SSVEPs) elicited by these stimuli. Visual processing of moving targets, as assessed by SSVEP amplitudes, was continuously facilitated relative to the processing of identical but irrelevant nontargets. The cortical sources of this enhancement were located to areas including early visual cortex V1-V3 and motion-sensitive area MT, suggesting that the sustained multifocal attentional enhancement during multiple object tracking already operates at hierarchically early stages of visual processing. Consistent with this interpretation, the magnitude of attentional facilitation during tracking in a single trial predicted the speed of target identification at the end of the trial. Together, these findings demonstrate that attention can flexibly and dynamically facilitate the processing of multiple independent object locations in early visual areas and thereby allow for tracking of these objects.

Within-hemifield competition in early visual areas limits the ability to track multiple objects with attention.

PubMed

Störmer, Viola S; Alvarez, George A; Cavanagh, Patrick

2014-08-27

It is much easier to divide attention across the left and right visual hemifields than within the same visual hemifield. Here we investigate whether this benefit of dividing attention across separate visual fields is evident at early cortical processing stages. We measured the steady-state visual evoked potential, an oscillatory response of the visual cortex elicited by flickering stimuli, of moving targets and distractors while human observers performed a tracking task. The amplitude of responses at the target frequencies was larger than that of the distractor frequencies when participants tracked two targets in separate hemifields, indicating that attention can modulate early visual processing when it is divided across hemifields. However, these attentional modulations disappeared when both targets were tracked within the same hemifield. These effects were not due to differences in task performance, because accuracy was matched across the tracking conditions by adjusting target speed (with control conditions ruling out effects due to speed alone). To investigate later processing stages, we examined the P3 component over central-parietal scalp sites that was elicited by the test probe at the end of the trial. The P3 amplitude was larger for probes on targets than on distractors, regardless of whether attention was divided across or within a hemifield, indicating that these higher-level processes were not constrained by visual hemifield. These results suggest that modulating early processing stages enables more efficient target tracking, and that within-hemifield competition limits the ability to modulate multiple target representations within the hemifield maps of the early visual cortex. Copyright © 2014 the authors 0270-6474/14/3311526-08$15.00/0.

Variability in clubhead presentation characteristics and ball impact location for golfers' drives.

PubMed

Betzler, Nils F; Monk, Stuart A; Wallace, Eric S; Otto, Steve R

2012-01-01

The purpose of the present study was to analyse the variability in clubhead presentation to the ball and the resulting ball impact location on the club face for a range of golfers of different ability. A total of 285 male and female participants hit multiple shots using one of four proprietary drivers. Self-reported handicap was used to quantify a participant's golfing ability. A bespoke motion capture system and user-written algorithms was used to track the clubhead just before and at impact, measuring clubhead speed, clubhead orientation, and impact location. A Doppler radar was used to measure golf ball speed. Generally, golfers of higher skill (lower handicap) generated increased clubhead speed and increased efficiency (ratio of ball speed to clubhead speed). Non-parametric statistical tests showed that low-handicap golfers exhibit significantly lower variability from shot to shot in clubhead speed, efficiency, impact location, attack angle, club path, and face angle compared with high-handicap golfers.

Estimation of Power Consumption in the Circular Sawing of Stone Based on Tangential Force Distribution

NASA Astrophysics Data System (ADS)

Huang, Guoqin; Zhang, Meiqin; Huang, Hui; Guo, Hua; Xu, Xipeng

2018-04-01

Circular sawing is an important method for the processing of natural stone. The ability to predict sawing power is important in the optimisation, monitoring and control of the sawing process. In this paper, a predictive model (PFD) of sawing power, which is based on the tangential force distribution at the sawing contact zone, was proposed, experimentally validated and modified. With regard to the influence of sawing speed on tangential force distribution, the modified PFD (MPFD) performed with high predictive accuracy across a wide range of sawing parameters, including sawing speed. The mean maximum absolute error rate was within 6.78%, and the maximum absolute error rate was within 11.7%. The practicability of predicting sawing power by the MPFD with few initial experimental samples was proved in case studies. On the premise of high sample measurement accuracy, only two samples are required for a fixed sawing speed. The feasibility of applying the MPFD to optimise sawing parameters while lowering the energy consumption of the sawing system was validated. The case study shows that energy use was reduced 28% by optimising the sawing parameters. The MPFD model can be used to predict sawing power, optimise sawing parameters and control energy.

New technique for real-time distortion-invariant multiobject recognition and classification

NASA Astrophysics Data System (ADS)

Hong, Rutong; Li, Xiaoshun; Hong, En; Wang, Zuyi; Wei, Hongan

2001-04-01

A real-time hybrid distortion-invariant OPR system was established to make 3D multiobject distortion-invariant automatic pattern recognition. Wavelet transform technique was used to make digital preprocessing of the input scene, to depress the noisy background and enhance the recognized object. A three-layer backpropagation artificial neural network was used in correlation signal post-processing to perform multiobject distortion-invariant recognition and classification. The C-80 and NOA real-time processing ability and the multithread programming technology were used to perform high speed parallel multitask processing and speed up the post processing rate to ROIs. The reference filter library was constructed for the distortion version of 3D object model images based on the distortion parameter tolerance measuring as rotation, azimuth and scale. The real-time optical correlation recognition testing of this OPR system demonstrates that using the preprocessing, post- processing, the nonlinear algorithm os optimum filtering, RFL construction technique and the multithread programming technology, a high possibility of recognition and recognition rate ere obtained for the real-time multiobject distortion-invariant OPR system. The recognition reliability and rate was improved greatly. These techniques are very useful to automatic target recognition.

Cognitive Function in Normal-Weight, Overweight, and Obese Older Adults: An Analysis of the Advanced Cognitive Training for Independent and Vital Elderly Cohort

PubMed Central

Kuo, Hsu-Ko; Jones, Richard N.; Milberg, William P.; Tennstedt, Sharon; Talbot, Laura; Morris, John N.; Lipsitz, Lewis A.

2010-01-01

OBJECTIVES To assess how elevated body mass index (BMI) affects cognitive function in elderly people. DESIGN Cross-sectional study. SETTING Data for this cross-sectional study were taken from a multicenter randomized controlled trial, the Advanced Cognitive Training for Independent and Vital Elderly trial. PARTICIPANTS The analytic sample included 2,684 normal-weight, overweight, or obese subjects aged 65 to 94. MEASUREMENTS Evaluation of cognitive abilities was performed in several domains: global cognition, memory, reasoning, and speed of processing. Cross-sectional association between body weight status and cognitive functions was analyzed using multiple linear regression. RESULTS Overweight subjects had better performance on a reasoning task (β = 0.23, standard error (SE) = 0.11, P = .04) and the Useful Field of View (UFOV) measure (β = −39.46, SE = 12.95, P = .002), a test of visuospatial speed of processing, after controlling for age, sex, race, years of education, intervention group, study site, and cardiovascular risk factors. Subjects with class I (BMI 30.0–34.9 kg/m2) and class II (BMI>35.0 kg/m2) obesity had better UFOV measure scores (β = −38.98, SE = 14.77, P = .008; β = −35.75, SE = 17.65, and P = .04, respectively) in the multivariate model than normal-weight subjects. The relationships between BMI and individual cognitive domains were nonlinear. CONCLUSION Overweight participants had better cognitive performance in terms of reasoning and visuospatial speed of processing than normal-weight participants. Obesity was associated with better performance in visuospatial speed of processing than normal weight. The relationship between BMI and cognitive function should be studied prospectively. PMID:16420204

Short-term wind speed prediction based on the wavelet transformation and Adaboost neural network

NASA Astrophysics Data System (ADS)

Hai, Zhou; Xiang, Zhu; Haijian, Shao; Ji, Wu

2018-03-01

The operation of the power grid will be affected inevitably with the increasing scale of wind farm due to the inherent randomness and uncertainty, so the accurate wind speed forecasting is critical for the stability of the grid operation. Typically, the traditional forecasting method does not take into account the frequency characteristics of wind speed, which cannot reflect the nature of the wind speed signal changes result from the low generality ability of the model structure. AdaBoost neural network in combination with the multi-resolution and multi-scale decomposition of wind speed is proposed to design the model structure in order to improve the forecasting accuracy and generality ability. The experimental evaluation using the data from a real wind farm in Jiangsu province is given to demonstrate the proposed strategy can improve the robust and accuracy of the forecasted variable.

Implementation of density-based solver for all speeds in the framework of OpenFOAM

NASA Astrophysics Data System (ADS)

Shen, Chun; Sun, Fengxian; Xia, Xinlin

2014-10-01

In the framework of open source CFD code OpenFOAM, a density-based solver for all speeds flow field is developed. In this solver the preconditioned all speeds AUSM+(P) scheme is adopted and the dual time scheme is implemented to complete the unsteady process. Parallel computation could be implemented to accelerate the solving process. Different interface reconstruction algorithms are implemented, and their accuracy with respect to convection is compared. Three benchmark tests of lid-driven cavity flow, flow crossing over a bump, and flow over a forward-facing step are presented to show the accuracy of the AUSM+(P) solver for low-speed incompressible flow, transonic flow, and supersonic/hypersonic flow. Firstly, for the lid driven cavity flow, the computational results obtained by different interface reconstruction algorithms are compared. It is indicated that the one dimensional reconstruction scheme adopted in this solver possesses high accuracy and the solver developed in this paper can effectively catch the features of low incompressible flow. Then via the test cases regarding the flow crossing over bump and over forward step, the ability to capture characteristics of the transonic and supersonic/hypersonic flows are confirmed. The forward-facing step proves to be the most challenging for the preconditioned solvers with and without the dual time scheme. Nonetheless, the solvers described in this paper reproduce the main features of this flow, including the evolution of the initial transient.

Blood glucose, diet-based glycemic load and cognitive aging among dementia-free older adults.

PubMed

Seetharaman, Shyam; Andel, Ross; McEvoy, Cathy; Dahl Aslan, Anna K; Finkel, Deborah; Pedersen, Nancy L

2015-04-01

Although evidence indicates that Type II Diabetes is related to abnormal brain aging, the influence of elevated blood glucose on long-term cognitive change is unclear. In addition, the relationship between diet-based glycemic load and cognitive aging has not been extensively studied. The focus of this study was to investigate the influence of diet-based glycemic load and blood glucose on cognitive aging in older adults followed for up to 16 years. Eight-hundred and thirty-eight cognitively healthy adults aged ≥50 years (M = 63.1, SD = 8.3) from the Swedish Adoption/Twin Study of Aging were studied. Mixed effects growth models were utilized to assess overall performance and change in general cognitive functioning, perceptual speed, memory, verbal ability, and spatial ability as a function of baseline blood glucose and diet-based glycemic load. High blood glucose was related to poorer overall performance on perceptual speed as well as greater rates of decline in general cognitive ability, perceptual speed, verbal ability, and spatial ability. Diet-based glycemic load was related to poorer overall performance in perceptual speed and spatial ability. Diet-based glycemic load and, in particular, elevated blood glucose appear important for cognitive performance/cognitive aging. Blood glucose control (perhaps through low glycemic load diets) may be an important target in the detection and prevention of age-related cognitive decline. © The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Robotic Attention Processing And Its Application To Visual Guidance

NASA Astrophysics Data System (ADS)

Barth, Matthew; Inoue, Hirochika

1988-03-01

This paper describes a method of real-time visual attention processing for robots performing visual guidance. This robot attention processing is based on a novel vision processor, the multi-window vision system that was developed at the University of Tokyo. The multi-window vision system is unique in that it only processes visual information inside local area windows. These local area windows are quite flexible in their ability to move anywhere on the visual screen, change their size and shape, and alter their pixel sampling rate. By using these windows for specific attention tasks, it is possible to perform high speed attention processing. The primary attention skills of detecting motion, tracking an object, and interpreting an image are all performed at high speed on the multi-window vision system. A basic robotic attention scheme using the attention skills was developed. The attention skills involved detection and tracking of salient visual features. The tracking and motion information thus obtained was utilized in producing the response to the visual stimulus. The response of the attention scheme was quick enough to be applicable to the real-time vision processing tasks of playing a video 'pong' game, and later using an automobile driving simulator. By detecting the motion of a 'ball' on a video screen and then tracking the movement, the attention scheme was able to control a 'paddle' in order to keep the ball in play. The response was faster than that of a human's, allowing the attention scheme to play the video game at higher speeds. Further, in the application to the driving simulator, the attention scheme was able to control both direction and velocity of a simulated vehicle following a lead car. These two applications show the potential of local visual processing in its use for robotic attention processing.

Contributions of early cortical processing and reading ability to functional status in individuals at clinical high risk for psychosis.

PubMed

Carrión, Ricardo E; Cornblatt, Barbara A; McLaughlin, Danielle; Chang, Jeremy; Auther, Andrea M; Olsen, Ruth H; Javitt, Daniel C

2015-05-01

There is a growing recognition that individuals at clinical high risk need intervention for functional impairments, along with emerging psychosis, as the majority of clinical high risk (CHR) individuals show persistent deficits in social and role functioning regardless of transition to psychosis. Recent studies have demonstrated reduced reading ability as a potential cause of functional disability in schizophrenia, related to underlying deficits in generation of mismatch negativity (MMN). The present study extends these findings to subjects at CHR. The sample consisted of 34 CHR individuals and 33 healthy comparison subjects (CNTLs) from the Recognition and Prevention (RAP) Program at the Zucker Hillside Hospital in New York. At baseline, reading measures were collected, along with MMN to pitch, duration, and intensity deviants, and measures of neurocognition, and social and role (academic/work) functioning. CHR subjects showed impairments in reading ability, neurocognition, and MMN generation, relative to CNTLs. Lower-amplitude MMN responses were correlated with worse reading ability, slower processing speed, and poorer social and role functioning. However, when entered into a simultaneous regression, only reduced responses to deviance in sound duration and volume predicted poor social and role functioning, respectively. Deficits in reading ability exist even prior to illness onset in schizophrenia and may represent a decline in performance from prior abilities. As in schizophrenia, deficits are related to impaired MMN generation, suggesting specific contributions of sensory-level impairment to neurocognitive processes related to social and role function. Copyright © 2015 Elsevier B.V. All rights reserved.

The integrated design and archive of space-borne signal processing and compression coding

NASA Astrophysics Data System (ADS)

He, Qiang-min; Su, Hao-hang; Wu, Wen-bo

2017-10-01

With the increasing demand of users for the extraction of remote sensing image information, it is very urgent to significantly enhance the whole system's imaging quality and imaging ability by using the integrated design to achieve its compact structure, light quality and higher attitude maneuver ability. At this present stage, the remote sensing camera's video signal processing unit and image compression and coding unit are distributed in different devices. The volume, weight and consumption of these two units is relatively large, which unable to meet the requirements of the high mobility remote sensing camera. This paper according to the high mobility remote sensing camera's technical requirements, designs a kind of space-borne integrated signal processing and compression circuit by researching a variety of technologies, such as the high speed and high density analog-digital mixed PCB design, the embedded DSP technology and the image compression technology based on the special-purpose chips. This circuit lays a solid foundation for the research of the high mobility remote sensing camera.

Simultaneity, Sequentiality, and Speed: Organizational Messages about Multiple-Task Completion

ERIC Educational Resources Information Center

Stephens, Keri K.; Cho, Jaehee K.; Ballard, Dawna I.

2012-01-01

Workplace norms for task completion increasingly value speed and the ability to accomplish multiple tasks at once. This study situates this popularized issue of multitasking within the context of chronemics scholarship by addressing related issues of simultaneity, sequentiality, and speed. Ultimately, we consider 2 multiple-task completion…

Towards real-time image deconvolution: application to confocal and STED microscopy

PubMed Central

Zanella, R.; Zanghirati, G.; Cavicchioli, R.; Zanni, L.; Boccacci, P.; Bertero, M.; Vicidomini, G.

2013-01-01

Although deconvolution can improve the quality of any type of microscope, the high computational time required has so far limited its massive spreading. Here we demonstrate the ability of the scaled-gradient-projection (SGP) method to provide accelerated versions of the most used algorithms in microscopy. To achieve further increases in efficiency, we also consider implementations on graphic processing units (GPUs). We test the proposed algorithms both on synthetic and real data of confocal and STED microscopy. Combining the SGP method with the GPU implementation we achieve a speed-up factor from about a factor 25 to 690 (with respect the conventional algorithm). The excellent results obtained on STED microscopy images demonstrate the synergy between super-resolution techniques and image-deconvolution. Further, the real-time processing allows conserving one of the most important property of STED microscopy, i.e the ability to provide fast sub-diffraction resolution recordings. PMID:23982127

The effects of Wechsler Intelligence Scale for Children-Fourth Edition cognitive abilities on math achievement.

PubMed

Parkin, Jason R; Beaujean, A Alexander

2012-02-01

This study used structural equation modeling to examine the effect of Stratum III (i.e., general intelligence) and Stratum II (i.e., Comprehension-Knowledge, Fluid Reasoning, Short-Term Memory, Processing Speed, and Visual Processing) factors of the Cattell-Horn-Carroll (CHC) cognitive abilities, as operationalized by the Wechsler Intelligence Scale for Children, Fourth Edition (WISC-IV; Wechsler, 2003a) subtests, on Quantitative Knowledge, as operationalized by the Wechsler Individual Achievement Test, Second Edition (WIAT-II; Wechsler, 2002) subtests. Participants came from the WISC-IV/WIAT-II linking sample (n=550). We compared models that predicted Quantitative Knowledge using only Stratum III factors, only Stratum II factors, and both Stratum III and Stratum II factors. Results indicated that the model with only the Stratum III factor predicting Quantitative Knowledge best fit the data. Copyright © 2011 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.

Application of high speed machining technology in aviation

NASA Astrophysics Data System (ADS)

Bałon, Paweł; Szostak, Janusz; Kiełbasa, Bartłomiej; Rejman, Edward; Smusz, Robert

2018-05-01

Aircraft structures are exposed to many loads during their working lifespan. Every particular action made during a flight is composed of a series of air movements which generate various aircraft loads. The most rigorous requirement which modern aircraft structures must fulfill is to maintain their high durability and reliability. This requirement involves taking many restrictions into account during the aircraft design process. The most important factor is the structure's overall mass, which has a crucial impact on both utility properties and cost-effectiveness. This makes aircraft one of the most complex results of modern technology. Additionally, there is currently an increasing utilization of high strength aluminum alloys, which requires the implementation of new manufacturing processes. High Speed Machining technology (HSM) is currently one of the most important machining technologies used in the aviation industry, especially in the machining of aluminium alloys. The primary difference between HSM and other milling techniques is the ability to select cutting parameters - depth of the cut layer, feed rate, and cutting speed in order to simultaneously ensure high quality, precision of the machined surface, and high machining efficiency, all of which shorten the manufacturing process of the integral components. In this paper, the authors explain the implementation of the HSM method in integral aircraft constructions. It presents the method of the airframe manufacturing method, and the final results. The HSM method is compared to the previous method where all subcomponents were manufactured by bending and forming processes, and then, they were joined by riveting.

A radial flow microfluidic device for ultra-high-throughput affinity-based isolation of circulating tumor cells.

PubMed

Murlidhar, Vasudha; Zeinali, Mina; Grabauskiene, Svetlana; Ghannad-Rezaie, Mostafa; Wicha, Max S; Simeone, Diane M; Ramnath, Nithya; Reddy, Rishindra M; Nagrath, Sunitha

2014-12-10

Circulating tumor cells (CTCs) are believed to play an important role in metastasis, a process responsible for the majority of cancer-related deaths. But their rarity in the bloodstream makes microfluidic isolation complex and time-consuming. Additionally the low processing speeds can be a hindrance to obtaining higher yields of CTCs, limiting their potential use as biomarkers for early diagnosis. Here, a high throughput microfluidic technology, the OncoBean Chip, is reported. It employs radial flow that introduces a varying shear profile across the device, enabling efficient cell capture by affinity at high flow rates. The recovery from whole blood is validated with cancer cell lines H1650 and MCF7, achieving a mean efficiency >80% at a throughput of 10 mL h(-1) in contrast to a flow rate of 1 mL h(-1) standardly reported with other microfluidic devices. Cells are recovered with a viability rate of 93% at these high speeds, increasing the ability to use captured CTCs for downstream analysis. Broad clinical application is demonstrated using comparable flow rates from blood specimens obtained from breast, pancreatic, and lung cancer patients. Comparable CTC numbers are recovered in all the samples at the two flow rates, demonstrating the ability of the technology to perform at high throughputs. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Independent examination of the Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV): what does the WAIS-IV measure?

PubMed

Benson, Nicholas; Hulac, David M; Kranzler, John H

2010-03-01

Published empirical evidence for the Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) does not address some essential questions pertaining to the applied practice of intellectual assessment. In this study, the structure and cross-age invariance of the latest WAIS-IV revision were examined to (a) elucidate the nature of the constructs measured and (b) determine whether the same constructs are measured across ages. Results suggest that a Cattell-Horn-Carroll (CHC)-inspired structure provides a better description of test performance than the published scoring structure does. Broad CHC abilities measured by the WAIS-IV include crystallized ability (Gc), fluid reasoning (Gf), visual processing (Gv), short-term memory (Gsm), and processing speed (Gs), although some of these abilities are measured more comprehensively than are others. Additionally, the WAIS-IV provides a measure of quantitative reasoning (QR). Results also suggest a lack of cross-age invariance resulting from age-related differences in factor loadings. Formulas for calculating CHC indexes and suggestions for interpretation are provided. PsycINFO Database Record (c) 2010 APA, all rights reserved.

Temporal Dynamics of Cognitive Performance and Anxiety Across Older Adulthood

PubMed Central

Petkus, Andrew J.; Reynolds, Chandra A.; Wetherell, Julie Loebach; Kremen, William S.; Gatz, Margaret

2017-01-01

Cognitive decline and anxiety symptoms commonly co-occur in later life, but the temporal order of changes on these two attributes is unclear. Specifically, it is unknown if greater anxiety leads to subsequent declines in cognitive performance or if worse cognitive performance leads to increased anxiety. In this study, we sought to elucidate the temporal dynamics between anxiety symptoms and cognitive performance across old age, that is, the extent to which level and change in one variable influence subsequent changes in a second variable. We examined data from 721 non-demented participants from the Swedish Adoption/Twin Study of Aging. Participants completed as many as eight assessments of cognitive performance and anxiety over a 26-year period. Bivariate dual change score models were fit to examine the dynamic association between anxiety and cognitive performance. Bidirectional associations between anxiety and cognitive performance were found among measures of processing speed, attention, and memory, but not visuospatial abilities. Higher anxiety was associated with greater declines in processing speed over the duration of six years and worsening attention over a span of three years. The reverse direction was also significant in that slower processing speed, worse attention, and poorer nonverbal and working memory performance were associated with larger increases in anxiety three years later. These findings highlight that in cognitively intact older adults, the association between anxiety and worse cognitive performance is bidirectional and complex. PMID:28333502

Age-related white matter microstructural differences partly mediate age-related decline in processing speed but not cognition.

PubMed

Salami, Alireza; Eriksson, Johan; Nilsson, Lars-Göran; Nyberg, Lars

2012-03-01

Aging is associated with declining cognitive performance as well as structural changes in brain gray and white matter (WM). The WM deterioration contributes to a disconnection among distributed brain networks and may thus mediate age-related cognitive decline. The present diffusion tensor imaging (DTI) study investigated age-related differences in WM microstructure and their relation to cognition (episodic memory, visuospatial processing, fluency, and speed) in a large group of healthy subjects (n=287) covering 6 decades of the human life span. Age related decreases in fractional anisotropy (FA) and increases in mean diffusivity (MD) were observed across the entire WM skeleton as well as in specific WM tracts, supporting the WM degeneration hypothesis. The anterior section of the corpus callosum was more susceptible to aging compared to the posterior section, lending support to the anterior-posterior gradient of WM integrity in the corpus callosum. Finally, and of critical interest, WM integrity differences were found to mediate age-related reductions in processing speed but no significant mediation was found for episodic memory, visuospatial ability, or fluency. These findings suggest that compromised WM integrity is not a major contributing factor to declining cognitive performance in normal aging. This article is part of a Special Issue entitled: Imaging Brain Aging and Neurodegenerative disease. Copyright © 2011 Elsevier B.V. All rights reserved.

Assessing the speed--accuracy trade-off effect on the capacity of information processing.

PubMed

Donkin, Chris; Little, Daniel R; Houpt, Joseph W

2014-06-01

The ability to trade accuracy for speed is fundamental to human decision making. The speed-accuracy trade-off (SAT) effect has received decades of study, and is well understood in relatively simple decisions: collecting more evidence before making a decision allows one to be more accurate but also slower. The SAT in more complex paradigms has been given less attention, largely due to limits in the models and statistics that can be applied to such tasks. Here, we have conducted the first analysis of the SAT in multiple signal processing, using recently developed technologies for measuring capacity that take into account both response time and choice probability. We show that the primary influence of caution in our redundant-target experiments is on the threshold amount of evidence required to trigger a response. However, in a departure from the usual SAT effect, we found that participants strategically ignored redundant information when they were forced to respond quickly, but only when the additional stimulus was reliably redundant. Interestingly, because the capacity of the system was severely limited on redundant-target trials, ignoring additional targets meant that processing was more efficient when making fast decisions than when making slow and accurate decisions, where participants' limited resources had to be divided between the 2 stimuli. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Global, broad, or specific cognitive differences? Using a MIMIC model to examine differences in CHC abilities in children with learning disabilities.

PubMed

Niileksela, Christopher R; Reynolds, Matthew R

2014-01-01

This study was designed to better understand the relations between learning disabilities and different levels of latent cognitive abilities, including general intelligence (g), broad cognitive abilities, and specific abilities based on the Cattell-Horn-Carroll theory of intelligence (CHC theory). Data from the Differential Ability Scales-Second Edition (DAS-II) were used to create a multiple-indicator multiple cause model to examine the latent mean differences in cognitive abilities between children with and without learning disabilities in reading (LD reading), math (LD math), and reading and writing(LD reading and writing). Statistically significant differences were found in the g factor between the norm group and the LD groups. After controlling for differences in g, the LD reading and LD reading and writing groups showed relatively lower latent processing speed, and the LD math group showed relatively higher latent comprehension-knowledge. There were also some differences in some specific cognitive abilities, including lower scores in spatial relations and numerical facility for the LD math group, and lower scores in visual memory for the LD reading and writing group. These specific mean differences were above and beyond any differences in the latent cognitive factor means.

Intrusive trauma recollections is associated with impairment of interference inhibition and psychomotor speed in PTSD.

PubMed

Kertzman, Semion; Avital, Avi; Weizman, Abraham; Segal, Michael

2014-10-01

Intrusive cognitions that enter consciousness involuntarily are prominent symptoms of posttraumatic stress disorder (PTSD). The present study aimed to identify neuropsychological mechanisms involved. Fifty PTSD outpatients and 50 healthy controls were tested using Finger Tapping, Simple and Choice Reaction Times and Stroop Tasks, to measure motor, psychomotor speed, response selection, and interference inhibition ability respectively. PTSD patients performed poorly in all tests, presumably owing to their generalized slowness of information processing and motor reaction. Psychomotor speed was a predictor of slowness and high error rate during the Stroop. Impaired inhibition, as measured by the interference index of the Stroop task, explained 9.7% of the predicated variance in frequency of re-experiencing PTSD symptoms and 23.5% of the predicated variance in augmentation of the interference response time. Impaired interference control may be related to internal (re-experiencing) and external (sensory) stimuli that leads to cognitive deficits in PTSD patients. Copyright © 2014 Elsevier Inc. All rights reserved.

Effects of major-road vehicle speed and driver age and gender on left-turn gap acceptance.

PubMed

Yan, Xuedong; Radwan, Essam; Guo, Dahai

2007-07-01

Because the driver's gap-acceptance maneuver is a complex and risky driving behavior, it is a highly concerned topic for traffic safety and operation. Previous studies have mainly focused on the driver's gap acceptance decision itself but did not pay attention to the maneuver process and driving behaviors. Using a driving simulator experiment for left-turn gap acceptance at a stop-controlled intersection, this study evaluated the effects of major traffic speed and driver age and gender on gap acceptance behaviors. The experiment results illustrate relationships among drivers' left-turn gap decision, driver's acceleration rate, steering action, and the influence of the gap-acceptance maneuver on the vehicles in the major traffic stream. The experiment results identified an association between high crash risk and high traffic speed at stop-controlled intersections. The older drivers, especially older female drivers, displayed a conservative driving attitude as a compensation for reduced driving ability, but also showed to be the most vulnerable group for the relatively complex driving maneuvers.

Predicting the size of individual and group differences on speeded cognitive tasks.

PubMed

Chen, Jing; Hale, Sandra; Myerson, Joel

2007-06-01

An a priori test of the difference engine model (Myerson, Hale, Zheng, Jenkins, & Widaman, 2003) was conducted using a large, diverse sample of individuals who performed three speeded verbal tasks and three speeded visuospatial tasks. Results demonstrated that, as predicted by the model, the group standard deviation (SD) on any task was proportional to the amount of processing required by that task. Both individual performances as well as those of fast and slow subgroups could be accurately predicted by the model using no free parameters, just an individual or subgroup's mean z-score and the values of theoretical constructs estimated from fits to the group SDs. Taken together, these results are consistent with post hoc analyses reported by Myerson et al. and provide even stronger supporting evidence. In particular, the ability to make quantitative predictions without using any free parameters provides the clearest demonstration to date of the power of an analytic approach on the basis of the difference engine.

Cortical Specializations Underlying Fast Computations

PubMed Central

Volgushev, Maxim

2016-01-01

The time course of behaviorally relevant environmental events sets temporal constraints on neuronal processing. How does the mammalian brain make use of the increasingly complex networks of the neocortex, while making decisions and executing behavioral reactions within a reasonable time? The key parameter determining the speed of computations in neuronal networks is a time interval that neuronal ensembles need to process changes at their input and communicate results of this processing to downstream neurons. Theoretical analysis identified basic requirements for fast processing: use of neuronal populations for encoding, background activity, and fast onset dynamics of action potentials in neurons. Experimental evidence shows that populations of neocortical neurons fulfil these requirements. Indeed, they can change firing rate in response to input perturbations very quickly, within 1 to 3 ms, and encode high-frequency components of the input by phase-locking their spiking to frequencies up to 300 to 1000 Hz. This implies that time unit of computations by cortical ensembles is only few, 1 to 3 ms, which is considerably faster than the membrane time constant of individual neurons. The ability of cortical neuronal ensembles to communicate on a millisecond time scale allows for complex, multiple-step processing and precise coordination of neuronal activity in parallel processing streams, while keeping the speed of behavioral reactions within environmentally set temporal constraints. PMID:25689988

RAYLEIGH–TAYLOR UNSTABLE FLAMES—FAST OR FASTER?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hicks, E. P., E-mail: eph2001@columbia.edu

2015-04-20

Rayleigh–Taylor (RT) unstable flames play a key role in the explosions of supernovae Ia. However, the dynamics of these flames are still not well understood. RT unstable flames are affected by both the RT instability of the flame front and by RT-generated turbulence. The coexistence of these factors complicates the choice of flame speed subgrid models for full-star Type Ia simulations. Both processes can stretch and wrinkle the flame surface, increasing its area and, therefore, the burning rate. In past research, subgrid models have been based on either the RT instability or turbulence setting the flame speed. We evaluate bothmore » models, checking their assumptions and their ability to correctly predict the turbulent flame speed. Specifically, we analyze a large parameter study of 3D direct numerical simulations of RT unstable model flames. This study varies both the simulation domain width and the gravity in order to probe a wide range of flame behaviors. We show that RT unstable flames are different from traditional turbulent flames: they are thinner rather than thicker when turbulence is stronger. We also show that none of the several different types of turbulent flame speed models accurately predicts measured flame speeds. In addition, we find that the RT flame speed model only correctly predicts the measured flame speed in a certain parameter regime. Finally, we propose that the formation of cusps may be the factor causing the flame to propagate more quickly than predicted by the RT model.« less

Rayleigh-Taylor Unstable Flames -- Fast or Faster?

NASA Astrophysics Data System (ADS)

Hicks, E. P.

2015-04-01

Rayleigh-Taylor (RT) unstable flames play a key role in the explosions of supernovae Ia. However, the dynamics of these flames are still not well understood. RT unstable flames are affected by both the RT instability of the flame front and by RT-generated turbulence. The coexistence of these factors complicates the choice of flame speed subgrid models for full-star Type Ia simulations. Both processes can stretch and wrinkle the flame surface, increasing its area and, therefore, the burning rate. In past research, subgrid models have been based on either the RT instability or turbulence setting the flame speed. We evaluate both models, checking their assumptions and their ability to correctly predict the turbulent flame speed. Specifically, we analyze a large parameter study of 3D direct numerical simulations of RT unstable model flames. This study varies both the simulation domain width and the gravity in order to probe a wide range of flame behaviors. We show that RT unstable flames are different from traditional turbulent flames: they are thinner rather than thicker when turbulence is stronger. We also show that none of the several different types of turbulent flame speed models accurately predicts measured flame speeds. In addition, we find that the RT flame speed model only correctly predicts the measured flame speed in a certain parameter regime. Finally, we propose that the formation of cusps may be the factor causing the flame to propagate more quickly than predicted by the RT model.

Cognitive abilities required in time judgment depending on the temporal tasks used: A comparison of children and adults.

PubMed

Droit-Volet, S; Wearden, J H; Zélanti, P S

2015-01-01

The aim of this study was to examine age-related differences in time judgments during childhood as a function of the temporal task used. Children aged 5 and 8 years, as well as adults, were submitted to 3 temporal tasks (bisection, generalization and reproduction) with short (0.4/0.8 s) and long durations (8/16 s). Furthermore, their cognitive capacities in terms of working memory, attentional control, and processing speed were assessed by a wide battery of neuropsychological tests. The results showed that the age-related differences in time judgment were greater in the reproduction task than in the temporal discrimination tasks. This task was indeed more demanding in terms of working memory and information processing speed. In addition, the bisection task appeared to be easier for children than the generalization task, whereas these 2 tasks were similar for the adults, although the generalization task required more attention to be paid to the processing of durations. Our study thus demonstrates that it is important to understand the different cognitive processes involved in time judgment as a function of the temporal tasks used before venturing to draw conclusions about the development of time perception capabilities.

Robotic Variable Polarity Plasma Arc (VPPA) Welding

NASA Technical Reports Server (NTRS)

Jaffery, Waris S.

1993-01-01

The need for automated plasma welding was identified in the early stages of the Space Station Freedom Program (SSFP) because it requires approximately 1.3 miles of welding for assembly. As a result of the Variable Polarity Plasma Arc Welding (VPPAW) process's ability to make virtually defect-free welds in aluminum, it was chosen to fulfill the welding needs. Space Station Freedom will be constructed of 2219 aluminum utilizing the computer controlled VPPAW process. The 'Node Radial Docking Port', with it's saddle shaped weld path, has a constantly changing surface angle over 360 deg of the 282 inch weld. The automated robotic VPPAW process requires eight-axes of motion (six-axes of robot and two-axes of positioner movement). The robot control system is programmed to maintain Torch Center Point (TCP) orientation perpendicular to the part while the part positioner is tilted and rotated to maintain the vertical up orientation as required by the VPPAW process. The combined speed of the robot and the positioner are integrated to maintain a constant speed between the part and the torch. A laser-based vision sensor system has also been integrated to track the seam and map the surface of the profile during welding.

A parallel implementation of an off-lattice individual-based model of multicellular populations

NASA Astrophysics Data System (ADS)

Harvey, Daniel G.; Fletcher, Alexander G.; Osborne, James M.; Pitt-Francis, Joe

2015-07-01

As computational models of multicellular populations include ever more detailed descriptions of biophysical and biochemical processes, the computational cost of simulating such models limits their ability to generate novel scientific hypotheses and testable predictions. While developments in microchip technology continue to increase the power of individual processors, parallel computing offers an immediate increase in available processing power. To make full use of parallel computing technology, it is necessary to develop specialised algorithms. To this end, we present a parallel algorithm for a class of off-lattice individual-based models of multicellular populations. The algorithm divides the spatial domain between computing processes and comprises communication routines that ensure the model is correctly simulated on multiple processors. The parallel algorithm is shown to accurately reproduce the results of a deterministic simulation performed using a pre-existing serial implementation. We test the scaling of computation time, memory use and load balancing as more processes are used to simulate a cell population of fixed size. We find approximate linear scaling of both speed-up and memory consumption on up to 32 processor cores. Dynamic load balancing is shown to provide speed-up for non-regular spatial distributions of cells in the case of a growing population.

Robotic Variable Polarity Plasma Arc (VPPA) welding

NASA Astrophysics Data System (ADS)

Jaffery, Waris S.

1993-02-01

The need for automated plasma welding was identified in the early stages of the Space Station Freedom Program (SSFP) because it requires approximately 1.3 miles of welding for assembly. As a result of the Variable Polarity Plasma Arc Welding (VPPAW) process's ability to make virtually defect-free welds in aluminum, it was chosen to fulfill the welding needs. Space Station Freedom will be constructed of 2219 aluminum utilizing the computer controlled VPPAW process. The 'Node Radial Docking Port', with it's saddle shaped weld path, has a constantly changing surface angle over 360 deg of the 282 inch weld. The automated robotic VPPAW process requires eight-axes of motion (six-axes of robot and two-axes of positioner movement). The robot control system is programmed to maintain Torch Center Point (TCP) orientation perpendicular to the part while the part positioner is tilted and rotated to maintain the vertical up orientation as required by the VPPAW process. The combined speed of the robot and the positioner are integrated to maintain a constant speed between the part and the torch. A laser-based vision sensor system has also been integrated to track the seam and map the surface of the profile during welding.

IQ as moderator of terminal decline in perceptual and motor speed, spatial, and verbal ability: Testing the cognitive reserve hypothesis in a population-based sample followed from age 70 until death.

PubMed

Thorvaldsson, Valgeir; Skoog, Ingmar; Johansson, Boo

2017-03-01

Terminal decline (TD) refers to acceleration in within-person cognitive decline prior to death. The cognitive reserve hypothesis postulates that individuals with higher IQ are able to better tolerate age-related increase in brain pathologies. On average, they will exhibit a later onset of TD, but once they start to decline, their trajectory is steeper relative to those with lower IQ. We tested these predictions using data from initially nondemented individuals (n = 179) in the H70-study repeatedly measured at ages 70, 75, 79, 81, 85, 88, 90, 92, 95, 97, 99, and 100, or until death, on cognitive tests of perceptual-and-motor-speed and spatial and verbal ability. We quantified IQ using the Raven's Coloured Progressive Matrices (RCPM) test administrated at age 70. We fitted random change point TD models to the data, within a Bayesian framework, conditioned on IQ, age of death, education, and sex. In line with predictions, we found that 1 additional standard deviation on the IQ scale was associated with a delay in onset of TD by 1.87 (95% highest density interval [HDI; 0.20, 4.08]) years on speed, 1.96 (95% HDI [0.15, 3.54]) years on verbal ability, but only 0.88 (95% HDI [-0.93, 3.49]) year on spatial ability. Higher IQ was associated with steeper rate of decline within the TD phase on measures of speed and verbal ability, whereas results on spatial ability were nonconclusive. Our findings provide partial support for the cognitive reserve hypothesis and demonstrate that IQ can be a significant moderator of cognitive change trajectories in old age. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Math Error Types and Correlates in Adolescents with and without Attention Deficit Hyperactivity Disorder

PubMed Central

Capodieci, Agnese; Martinussen, Rhonda

2017-01-01

Objective: The aim of this study was to examine the types of errors made by youth with and without a parent-reported diagnosis of attention deficit and hyperactivity disorder (ADHD) on a math fluency task and investigate the association between error types and youths’ performance on measures of processing speed and working memory. Method: Participants included 30 adolescents with ADHD and 39 typically developing peers between 14 and 17 years old matched in age and IQ. All youth completed standardized measures of math calculation and fluency as well as two tests of working memory and processing speed. Math fluency error patterns were examined. Results: Adolescents with ADHD showed less proficient math fluency despite having similar math calculation scores as their peers. Group differences were also observed in error types with youth with ADHD making more switch errors than their peers. Conclusion: This research has important clinical applications for the assessment and intervention on math ability in students with ADHD. PMID:29075227

Real-time tracking using stereo and motion: Visual perception for space robotics

NASA Technical Reports Server (NTRS)

Nishihara, H. Keith; Thomas, Hans; Huber, Eric; Reid, C. Ann

1994-01-01

The state-of-the-art in computing technology is rapidly attaining the performance necessary to implement many early vision algorithms at real-time rates. This new capability is helping to accelerate progress in vision research by improving our ability to evaluate the performance of algorithms in dynamic environments. In particular, we are becoming much more aware of the relative stability of various visual measurements in the presence of camera motion and system noise. This new processing speed is also allowing us to raise our sights toward accomplishing much higher-level processing tasks, such as figure-ground separation and active object tracking, in real-time. This paper describes a methodology for using early visual measurements to accomplish higher-level tasks; it then presents an overview of the high-speed accelerators developed at Teleos to support early visual measurements. The final section describes the successful deployment of a real-time vision system to provide visual perception for the Extravehicular Activity Helper/Retriever robotic system in tests aboard NASA's KC135 reduced gravity aircraft.

Math Error Types and Correlates in Adolescents with and without Attention Deficit Hyperactivity Disorder.

PubMed

Capodieci, Agnese; Martinussen, Rhonda

2017-01-01

Objective: The aim of this study was to examine the types of errors made by youth with and without a parent-reported diagnosis of attention deficit and hyperactivity disorder (ADHD) on a math fluency task and investigate the association between error types and youths' performance on measures of processing speed and working memory. Method: Participants included 30 adolescents with ADHD and 39 typically developing peers between 14 and 17 years old matched in age and IQ. All youth completed standardized measures of math calculation and fluency as well as two tests of working memory and processing speed. Math fluency error patterns were examined. Results: Adolescents with ADHD showed less proficient math fluency despite having similar math calculation scores as their peers. Group differences were also observed in error types with youth with ADHD making more switch errors than their peers. Conclusion: This research has important clinical applications for the assessment and intervention on math ability in students with ADHD.

Cognitive Predictors of Everyday Problem Solving across the Lifespan

PubMed Central

Chen, Xi; Hertzog, Christopher; Park, Denise C.

2017-01-01

Background An important aspect of successful aging is maintaining the ability to solve everyday problems encountered in daily life. The limited evidence today suggests that everyday problem solving ability increases from young adulthood to middle age, but decreases in older age. Objectives The present study examined age differences in the relative contributions of fluid and crystallized abilities to solving problems on the Everyday Problems Test (EPT; [1]). We hypothesized that due to diminishing fluid resources available with advanced age, crystallized knowledge would become increasingly important in predicting everyday problem solving with greater age. Method Two hundred and twenty-one healthy adults from the Dallas Lifespan Brain Study, aged 24–93 years, completed a cognitive battery that included measures of fluid ability (i.e., processing speed, working memory, inductive reasoning) and crystallized ability (i.e., multiple measures of vocabulary). These measures were used to predict performance on the Everyday Problems Test. Results Everyday problem solving showed an increase in performance from young to early middle age, with performance beginning to decrease at about age of fifty. As hypothesized, fluid ability was the primary predictor of performance on everyday problem solving for young adults, but with increasing age, crystallized ability became the dominant predictor. Conclusion This study provides evidence that everyday problem solving ability differs with age, and, more importantly, that the processes underlying it differ with age as well. The findings indicate that older adults increasingly rely on knowledge to support everyday problem solving, whereas young adults rely almost exclusively on fluid intelligence. PMID:28273664

The development of visuo-spatial working memory.

PubMed

Pickering, S J

2001-01-01

Children's performance on tests of visuo-spatial working memory improves with age, although relatively little is known about why this happens. One explanation concerns the development of the ability to recode visually presented information into phonological form. This process appears to be used from around 8 years of age and is a major contributor to tasks in which stimuli can be verbally labelled. However, evidence suggests that phonological recoding cannot account for all of the age-related change in performance on visuo-spatial working memory tasks. In this review, four other mechanisms (knowledge, processing strategies, processing speed, and attentional capacity) are considered in terms of their contribution to children's visuo-spatial working memory development.

A new model of selection in women's handball.

PubMed

Srhoj, Vatromir; Rogulj, Nenad; Zagorac, Nebojsa; Katić, Ratko

2006-09-01

The aim of the study was to assess the basic motor abilities that determine top performance in women's handball, and to identify test panel for primary selection at handball school. The study included 155 female attendants of the Split Handball School, mean age 12.5 years. Differences in the basic motor abilities between the subjects that developed into elite handball players after 7-year training process and those that abandoned handball for being unable to meet the competition criteria were evaluated by use of discriminative analysis. The former were found to have also been superior initially in all variables analyzed, and in arm coordination, overall body coordination, throw and jump explosive strength, arm movement frequency and repetitive trunk strength in particular. Motor superiority based on the abilities of coordination, explosive strength and speed determines performance in women's handball, qualifying these abilities as reliable selection criteria. Based on this study results, a new model of selection in women's handball, with fine arm coordination as the major limiting factor of performance, has been proposed.

Cognitive abilities predict death during the next 15 years in older Japanese adults.

PubMed

Nishita, Yukiko; Tange, Chikako; Tomida, Makiko; Otsuka, Rei; Ando, Fujiko; Shimokata, Hiroshi

2017-10-01

The longitudinal relationship between cognitive abilities and subsequent death was investigated among community-dwelling older Japanese adults. Participants (n = 1060; age range 60-79 years) comprised the first-wave participants of the National Institute for Longevity Sciences-Longitudinal Study of Aging. Participants' cognitive abilities were measured at baseline using the Japanese Wechsler Adult Intelligence Scale-Revised Short Form, which includes the following tests: Information (general knowledge), Similarities (logical abstract thinking), Picture Completion (visual perception and long-term visual memory) and Digit Symbol (information processing speed). By each cognitive test score, participants were classified into three groups: the high-level group (≥ the mean + 1SD), the low-level group (≤ the mean - 1SD) and the middle-level group. Data on death and moving during the subsequent 15 years were collected and analyzed using the multiple Cox proportional hazard model adjusted for physical and psychosocial covariates. During the follow-up period, 308 participants (29.06%) had died and 93 participants (8.77%) had moved. In the Similarities test, adjusted hazard ratios (HR) of the low-level group to the high-level group were significant (HR 1.49, 95% CI 1.02-2.17, P = 0.038). Furthermore, in the Digit symbol test, the adjusted HR of the low-level group to the high-level group was significant (HR 1.62, 95% CI 1.03-2.58, P = 0.038). Significant adjusted HR were not observed for the Information or Picture Completion tests. It is suggested that a lower level of logical abstract thinking and slower information processing speed are associated with shorter survival among older Japanese adults. Geriatr Gerontol Int 2017; 17: 1654-1660. © 2016 Japan Geriatrics Society.

Cognitive Predictors of Word and Pseudoword Reading in Spanish First-Grade Children

PubMed Central

González-Valenzuela, María J.; Díaz-Giráldez, Félix; López-Montiel, María D.

2016-01-01

The study examines the individual and combined contribution of several cognitive variables (phonemic awareness, phonological memory, and alphanumeric and non-alphanumeric rapid naming) to word and pseudoword reading ability among first-grade Spanish children. Participants were 116 Spanish-speaking children aged 6 years and without special educational needs, all of whom were attending schools in a medium socioeconomic area. Descriptive/exploratory and bivariate analyses were performed with the data derived from three measures of reading ability (accuracy, speed, and efficiency), and hierarchical multivariate regression models were constructed. In general, the results confirm that, with the exception of non-alphanumeric rapid naming, the cognitive variables studied are predictors of reading performance for words and pseudowords, although their influence differs depending on the reading measures and type of linguistic unit considered. Phonemic awareness, phonological memory, and alphanumeric rapid naming were the best predictors of reading accuracy for words and pseudowords. Variability in the other two measures of reading ability (speed and efficiency) was best explained by alphanumeric rapid naming. These results suggest that reading is a complex skill that depends on different types of cognitive variables according to the age and/or level of the reader, the type of orthography and the type of measure used. Furthermore, they highlight the need to provide instruction in these processes from an early age so as to address or prevent the problems that children may present. PMID:27303336

The effect of donepezil on the cognitive ability early in the course of recovery from traumatic brain injury.

PubMed

Campbell, Kelsey A; Kennedy, Richard E; Brunner, Robert C; Hollis, Sean D; Lumsden, Ross A; Novack, Thomas A

2018-05-08

To investigate the effect of donepezil on cognitive ability in patients who have sustained a traumatic brain injury (TBI). We hypothesized that donepezil, an acetylcholinesterase inhibitor, would enhance cognitive recovery beyond that of usual care in an acute rehabilitation facility. This retrospective, longitudinal analysis included 55 patients who were non-randomly prescribed donepezil during acute care and compared them to 74 patients who received usual rehabilitation treatment. All 129 patients completed neuropsychological assessment at two time points. Donepezil was increased from 5 to 10 mg 7-10 days after initiation and maintained until follow-up cognitive assessment. Primary cognitive abilities of interest included processing speed, attention and memory. Cognitive and functional abilities were assessed by a standard neuropsychological battery for TBI. Propensity scores were used to adjust for differences between groups. Mixed effect model analysis showed no significant differences between treatment and control groups on all neuropsychological subtests over time. Acute administration of donepezil did not significantly improve measures of cognitive or functional ability beyond that of treatment as usual in patients with moderate-to-severe TBI.

Reading Comprehension in Children with ADHD: Cognitive Underpinnings of the Centrality Deficit

PubMed Central

Miller, Amanda C.; Keenan, Janice M.; Betjemann, Rebecca S.; Willcutt, Erik; Pennington, Bruce F.; Olson, Richard K.

2012-01-01

We examined reading comprehension in children with ADHD by assessing their ability to build a coherent mental representation that allows them to recall central and peripheral information. We compared children with ADHD (mean age 9.78) to word reading-matched controls (mean age 9.89) on their ability to retell a passage. We found that even though children with ADHD recalled more central than peripheral information, they showed their greatest deficit, relative to controls, on central information – a centrality deficit (Miller & Keenan, 2009). We explored the cognitive underpinnings of this deficit using regressions to compare how well cognitive factors (working memory, inhibition, processing speed, and IQ) predicted the ability to recall central information, after controlling for word reading ability, and whether these cognitive factors interacted with ADHD symptoms. Working memory accounted for the most unique variance. Although previous evidence for reading comprehension difficulties in children with ADHD have been mixed, this study suggests that even when word reading ability is controlled, children with ADHD have difficulty building a coherent mental representation, and this difficulty is likely related to deficits in working memory. PMID:23054132

Volumetric analysis of cerebellum in short-track speed skating players.

PubMed

Park, In Sung; Lee, Nam Joon; Kim, Tae-Young; Park, Jin-Hoon; Won, Yu-Mi; Jung, Yong-Ju; Yoon, Jin-Hwan; Rhyu, Im Joo

2012-12-01

The cerebellum is associated with balance control and coordination, which might be important for gliding on smooth ice at high speeds. A number of case studies have shown that cerebellar damage induces impaired balance and coordination. As a positive model, therefore, we investigated whether plastic changes in the volumes of cerebellar subregions occur in short-track speed skating players who must have extraordinary abilities of balance and coordination, using three-dimensional magnetic resonance imaging volumetry. The manual tracing was performed and the volumes of cerebellar hemisphere and vermian lobules were compared between short-track speed skating players (n=16) and matched healthy controls (n=18). We found larger right cerebellar hemisphere volume and vermian lobules VI-VII (declive, folium, and tuber) in short-track speed skating players in comparison with the matched controls. The finding suggests that the specialized abilities of balance and coordination are associated with structural plasticity of the right hemisphere of cerebellum and vermian VI-VII and these regions play an essential role in balance and coordination.

A laboratory evaluation of four quality control devices for radiographic processing.

PubMed

Rushton, V E; Horner, K

1994-08-01

Quality assurance programmes for radiographic processing traditionally employ expensive sensitometric and densitometric techniques. However cheap and simple devices for monitoring radiographic processing are available. The aim of this study was to make a comparison of four such devices in terms of their ability to detect variations in radiographic density of clinical significance. Three of the devices are commercially available while the fourth is easily manufactured from waste materials. Ideal bitewing exposure times were selected for four different kilovoltage/film speed combinations. Phantom bitewing radiographs, exposed using these exposure times, were processed using a variety of times and developer temperatures to simulate variations in radiographic quality due to inadequate processing conditions. Test films, produced using the four monitoring devices, were exposed and processed under identical conditions. The phantom bitewings were judged to have 'acceptable' quality when the optical density of that part of the film not showing calcified structures was within +/- 0.5 of that of the film processed under optimal conditions. The efficacy of the monitoring devices in indicating the adequacy of processing was assessed by a comparison of their readings with those made from the phantom bitewings. None of the monitoring devices was ideal for all the kilovoltage/film speed combinations tested, but the homemade device proved to be the most generally effective. We conclude that guidelines to dentists on radiographic quality assurance should include reference to and details of this simple device.

Swimming Speed of Larval Snail Does Not Correlate with Size and Ciliary Beat Frequency

PubMed Central

Chan, Kit Yu Karen; Jiang, Houshuo; Padilla, Dianna K.

2013-01-01

Many marine invertebrates have planktonic larvae with cilia used for both propulsion and capturing of food particles. Hence, changes in ciliary activity have implications for larval nutrition and ability to navigate the water column, which in turn affect survival and dispersal. Using high-speed high-resolution microvideography, we examined the relationship between swimming speed, velar arrangements, and ciliary beat frequency of freely swimming veliger larvae of the gastropod Crepidula fornicata over the course of larval development. Average swimming speed was greatest 6 days post hatching, suggesting a reduction in swimming speed towards settlement. At a given age, veliger larvae have highly variable speeds (0.8–4 body lengths s−1) that are independent of shell size. Contrary to the hypothesis that an increase in ciliary beat frequency increases work done, and therefore speed, there was no significant correlation between swimming speed and ciliary beat frequency. Instead, there are significant correlations between swimming speed and visible area of the velar lobe, and distance between centroids of velum and larval shell. These observations suggest an alternative hypothesis that, instead of modifying ciliary beat frequency, larval C. fornicata modify swimming through adjustment of velum extension or orientation. The ability to adjust velum position could influence particle capture efficiency and fluid disturbance and help promote survival in the plankton. PMID:24367554

Theory of mind through the ages: older and middle-aged adults exhibit more errors than do younger adults on a continuous false belief task.

PubMed

Bernstein, Daniel M; Thornton, Wendy Loken; Sommerville, Jessica A

2011-10-01

Theory of mind (ToM), or the ability to understand mental states, is a fundamental aspect of social cognition. Previous research has documented marked advances in ToM in preschoolers, and declines in ToM in older-aged adults. In the present study, younger (n=37), middle-aged (n=20), and older (n=37) adults completed a continuous false belief task measuring ToM. Middle-aged and older adults exhibited more false belief bias than did younger adults, irrespective of language ability, executive function, processing speed, and memory. The authors conclude that ToM declines from younger to older adulthood, independent of age-related changes to domain-general cognitive functioning.

Novel grid-based optical Braille conversion: from scanning to wording

NASA Astrophysics Data System (ADS)

Yoosefi Babadi, Majid; Jafari, Shahram

2011-12-01

Grid-based optical Braille conversion (GOBCO) is explained in this article. The grid-fitting technique involves processing scanned images taken from old hard-copy Braille manuscripts, recognising and converting them into English ASCII text documents inside a computer. The resulted words are verified using the relevant dictionary to provide the final output. The algorithms employed in this article can be easily modified to be implemented on other visual pattern recognition systems and text extraction applications. This technique has several advantages including: simplicity of the algorithm, high speed of execution, ability to help visually impaired persons and blind people to work with fax machines and the like, and the ability to help sighted people with no prior knowledge of Braille to understand hard-copy Braille manuscripts.

Fast tunable blazed MEMS grating for external cavity lasers

NASA Astrophysics Data System (ADS)

Tormen, Maurizio; Niedermann, Philippe; Hoogerwerf, Arno; Shea, Herbert; Stanley, Ross

2017-11-01

Diffractive MEMS are interesting for a wide range of applications, including displays, scanners or switching elements. Their advantages are compactness, potentially high actuation speed and in the ability to deflect light at large angles. We have designed and fabricated deformable diffractive MEMS grating to be used as tuning elements for external cavity lasers. The resulting device is compact, has wide tunability and a high operating speed. The initial design is a planar grating where the beams are free-standing and attached to each other using leaf springs. Actuation is achieved through two electrostatic comb drives at either end of the grating. To prevent deformation of the free-standing grating, the device is 10 μm thick made from a Silicon on Insulator (SOI) wafer in a single mask process. At 100V a periodicity tuning of 3% has been measured. The first resonant mode of the grating is measured at 13.8 kHz, allowing high speed actuation. This combination of wide tunability and high operating speed represents state of the art in the domain of tunable MEMS filters. In order to improve diffraction efficiency and to expand the usable wavelength range, a blazed version of the deformable MEMS grating has been designed. A key issue is maintaining the mechanical properties of the original device while providing optically smooth blazed beams. Using a process based on anisotropic KOH etching, blazed gratings have been obtained and preliminary characterization is promising.

Association of visual sensory function and higher order visual processing skills with incident driving cessation

PubMed Central

Huisingh, Carrie; McGwin, Gerald; Owsley, Cynthia

2017-01-01

Background Many studies on vision and driving cessation have relied on measures of sensory function, which are insensitive to the higher order cognitive aspects of visual processing. The purpose of this study was to examine the association between traditional measures of visual sensory function and higher order visual processing skills with incident driving cessation in a population-based sample of older drivers. Methods Two thousand licensed drivers aged ≥70 were enrolled and followed-up for three years. Tests for central vision and visual processing were administered at baseline and included visual acuity, contrast sensitivity, sensitivity in the driving visual field, visual processing speed (Useful Field of View (UFOV) Subtest 2 and Trails B), and spatial ability measured by the Visual Closure Subtest of the Motor-free Visual Perception Test. Participants self-reported the month and year of driving cessation and provided a reason for cessation. Cox proportional hazards models were used to generate crude and adjusted hazard ratios with 95% confidence intervals between visual functioning characteristics and risk of driving cessation over a three-year period. Results During the study period, 164 participants stopped driving which corresponds to a cumulative incidence of 8.5%. Impaired contrast sensitivity, visual fields, visual processing speed (UFOVand Trails B), and spatial ability were significant risk factors for subsequent driving cessation after adjusting for age, gender, marital status, number of medical conditions, and miles driven. Visual acuity impairment was not associated with driving cessation. Medical problems (63%), specifically musculoskeletal and neurological problems, as well as vision problems (17%) were cited most frequently as the reason for driving cessation. Conclusion Assessment of cognitive and visual functioning can provide useful information about subsequent risk of driving cessation among older drivers. In addition, a variety of factors, not just vision, influenced the decision to stop driving and may be amenable to intervention. PMID:27353969

Oral and Hand Movement Speeds Are Associated with Expressive Language Ability in Children with Speech Sound Disorder

ERIC Educational Resources Information Center

Peter, Beate

2012-01-01

This study tested the hypothesis that children with speech sound disorder have generalized slowed motor speeds. It evaluated associations among oral and hand motor speeds and measures of speech (articulation and phonology) and language (receptive vocabulary, sentence comprehension, sentence imitation), in 11 children with moderate to severe SSD…

The Role of Visual Processing Speed in Reading Speed Development

PubMed Central

Lobier, Muriel; Dubois, Matthieu; Valdois, Sylviane

2013-01-01

A steady increase in reading speed is the hallmark of normal reading acquisition. However, little is known of the influence of visual attention capacity on children's reading speed. The number of distinct visual elements that can be simultaneously processed at a glance (dubbed the visual attention span), predicts single-word reading speed in both normal reading and dyslexic children. However, the exact processes that account for the relationship between the visual attention span and reading speed remain to be specified. We used the Theory of Visual Attention to estimate visual processing speed and visual short-term memory capacity from a multiple letter report task in eight and nine year old children. The visual attention span and text reading speed were also assessed. Results showed that visual processing speed and visual short term memory capacity predicted the visual attention span. Furthermore, visual processing speed predicted reading speed, but visual short term memory capacity did not. Finally, the visual attention span mediated the effect of visual processing speed on reading speed. These results suggest that visual attention capacity could constrain reading speed in elementary school children. PMID:23593117

The role of visual processing speed in reading speed development.

PubMed

Lobier, Muriel; Dubois, Matthieu; Valdois, Sylviane

2013-01-01

A steady increase in reading speed is the hallmark of normal reading acquisition. However, little is known of the influence of visual attention capacity on children's reading speed. The number of distinct visual elements that can be simultaneously processed at a glance (dubbed the visual attention span), predicts single-word reading speed in both normal reading and dyslexic children. However, the exact processes that account for the relationship between the visual attention span and reading speed remain to be specified. We used the Theory of Visual Attention to estimate visual processing speed and visual short-term memory capacity from a multiple letter report task in eight and nine year old children. The visual attention span and text reading speed were also assessed. Results showed that visual processing speed and visual short term memory capacity predicted the visual attention span. Furthermore, visual processing speed predicted reading speed, but visual short term memory capacity did not. Finally, the visual attention span mediated the effect of visual processing speed on reading speed. These results suggest that visual attention capacity could constrain reading speed in elementary school children.

The cognitive foundations of reading and arithmetic skills in 7- to 10-year-olds.

PubMed

Durand, Marianne; Hulme, Charles; Larkin, Rebecca; Snowling, Margaret

2005-06-01

A range of possible predictors of arithmetic and reading were assessed in a large sample (N=162) of children between ages 7 years 5 months and 10 years 4 months. A confirmatory factor analysis of the predictors revealed a good fit to a model consisting of four latent variables (verbal ability, nonverbal ability, search speed, and phonological memory) and two manifest variables (digit comparison and phoneme deletion). A path analysis showed that digit comparison and verbal ability were unique predictors of variations in arithmetic skills, whereas phoneme deletion and verbal ability were unique predictors of variations in reading skills. These results confirm earlier findings that phoneme deletion ability appears to be a critical foundation for learning to read (decode). In addition, variations in the speed of accessing numerical quantity information appear to be a critical foundation for the development of arithmetic skills.

Brain white matter damage in aging and cognitive ability in youth and older age☆

PubMed Central

Valdés Hernández, Maria del C.; Booth, Tom; Murray, Catherine; Gow, Alan J.; Penke, Lars; Morris, Zoe; Maniega, Susana Muñoz; Royle, Natalie A.; Aribisala, Benjamin S.; Bastin, Mark E.; Starr, John M.; Deary, Ian J.; Wardlaw, Joanna M.

2013-01-01

Cerebral white matter hyperintensities (WMH) reflect accumulating white matter damage with aging and impair cognition. The role of childhood intelligence is rarely considered in associations between cognitive impairment and WMH. We studied community-dwelling older people all born in 1936, in whom IQ had been assessed at age 11 years. We assessed medical histories, current cognitive ability and quantified WMH on MR imaging. Among 634 participants, mean age 72.7 (SD 0.7), age 11 IQ was the strongest predictor of late life cognitive ability. After accounting for age 11 IQ, greater WMH load was significantly associated with lower late life general cognitive ability (β = −0.14, p < 0.01) and processing speed (β = −0.19, p < 0.001). WMH were also associated independently with lower age 11 IQ (β = −0.08, p < 0.05) and hypertension. In conclusion, having more WMH is significantly associated with lower cognitive ability, after accounting for prior ability, age 11IQ. Early-life IQ also influenced WMH in later life. Determining how lower IQ in youth leads to increasing brain damage with aging is important for future successful cognitive aging. PMID:23850341

Fronto-Parietal Network Reconfiguration Supports the Development of Reasoning Ability

PubMed Central

Wendelken, Carter; Ferrer, Emilio; Whitaker, Kirstie J.; Bunge, Silvia A.

2016-01-01

The goal of this fMRI study was to examine how well developmental improvements in reasoning ability can be explained by changes in functional connectivity between specific nodes in prefrontal and parietal cortices. To this end, we examined connectivity within the lateral fronto-parietal network (LFPN) and its relation to reasoning ability in 132 children and adolescents aged 6–18 years, 56 of whom were scanned twice over the course of 1.5 years. Developmental changes in strength of connections within the LFPN were most prominent in late childhood and early adolescence. Reasoning ability was related to functional connectivity between left rostrolateral prefrontal cortex (RLPFC) and inferior parietal lobule (IPL), but only among 12–18-year olds. For 9–11-year olds, reasoning ability was most strongly related to connectivity between left and right RLPFC; this relationship was mediated by working memory. For 6–8-year olds, significant relationships between connectivity and performance were not observed; in this group, processing speed was the primary mediator of improvement in reasoning ability. We conclude that different connections best support reasoning at different points in development and that RLPFC-IPL connectivity becomes an important predictor of reasoning during adolescence. PMID:25824536

Speed isn’t everything: Complex processing speed measures mask individual differences and developmental changes in executive control

PubMed Central

Cepeda, Nicholas J.; Blackwell, Katharine A.; Munakata, Yuko

2012-01-01

The rate at which people process information appears to influence many aspects of cognition across the lifespan. However, many commonly accepted measures of “processing speed” may require goal maintenance, manipulation of information in working memory, and decision-making, blurring the distinction between processing speed and executive control and resulting in overestimation of processing-speed contributions to cognition. This concern may apply particularly to studies of developmental change, as even seemingly simple processing speed measures may require executive processes to keep children and older adults on task. We report two new studies and a re-analysis of a published study, testing predictions about how different processing speed measures influence conclusions about executive control across the life span. We find that the choice of processing speed measure affects the relationship observed between processing speed and executive control, in a manner that changes with age, and that choice of processing speed measure affects conclusions about development and the relationship among executive control measures. Implications for understanding processing speed, executive control, and their development are discussed. PMID:23432836

Jump Squat is More Related to Sprinting and Jumping Abilities than Olympic Push Press.

PubMed

Loturco, I; Kobal, R; Maldonado, T; Piazzi, A F; Bottino, A; Kitamura, K; Abad, C C C; Pereira, L A; Nakamura, F Y

2017-07-01

The aim of this study was to test the relationships between jump squat (JS) and Olympic push press (OPP) power outputs and performance in sprint, squat jump (SJ), countermovement jump (CMJ) and change of direction (COD) speed tests in elite soccer players. 27 athletes performed a maximum power load test to determine their bar mean propulsive power (MPP) and bar mean propulsive velocity (MPV) in the JS and OPP exercises. Magnitude-based inference was used to compare the exercises. The MPV was almost certainly higher in the OPP than in the JS. The MPP relative to body mass (MPP REL) was possibly higher in the OPP. Only the JS MPP REL presented very large correlations with linear speed ( r> 0.7, for speed in 5, 10, 20 and 30 m) and vertical jumping abilities ( r> 0.8, for SJ and CMJ), and moderate correlation with COD speed ( r= 0.45). Although significant (except for COD), the associations between OPP outcomes and field-based measurements (speed, SJ and CMJ) were all moderate, ranging from 0.40 to 0.48. In a group composed of elite soccer players, the JS exercise is more associated with jumping and sprinting abilities than the OPP. Longitudinal studies are needed to confirm if these strong relationships imply superior training effects in favor of the JS exercise. © Georg Thieme Verlag KG Stuttgart · New York.

Mental object rotation in Parkinson's disease.

PubMed

Crucian, Gregory P; Barrett, Anna M; Burks, David W; Riestra, Alonso R; Roth, Heidi L; Schwartz, Ronald L; Triggs, William J; Bowers, Dawn; Friedman, William; Greer, Melvin; Heilman, Kenneth M

2003-11-01

Deficits in visual-spatial ability can be associated with Parkinson's disease (PD), and there are several possible reasons for these deficits. Dysfunction in frontal-striatal and/or frontal-parietal systems, associated with dopamine deficiency, might disrupt cognitive processes either supporting (e.g., working memory) or subserving visual-spatial computations. The goal of this study was to assess visual-spatial orientation ability in individuals with PD using the Mental Rotations Test (MRT), along with other measures of cognitive function. Non-demented men with PD were significantly less accurate on this test than matched control men. In contrast, women with PD performed similarly to matched control women, but both groups of women did not perform much better than chance. Further, mental rotation accuracy in men correlated with their executive skills involving mental processing and psychomotor speed. In women with PD, however, mental rotation accuracy correlated negatively with verbal memory, indicating that higher mental rotation performance was associated with lower ability in verbal memory. These results indicate that PD is associated with visual-spatial orientation deficits in men. Women with PD and control women both performed poorly on the MRT, possibly reflecting a floor effect. Although men and women with PD appear to engage different cognitive processes in this task, the reason for the sex difference remains to be elucidated.

Novice to Expert Cognition During Geologic Bedrock Mapping

NASA Astrophysics Data System (ADS)

Petcovic, H. L.; Libarkin, J.; Hambrick, D. Z.; Baker, K. M.; Elkins, J. T.; Callahan, C. N.; Turner, S.; Rench, T. A.; LaDue, N.

2011-12-01

Bedrock geologic mapping is a complex and cognitively demanding task. Successful mapping requires domain-specific content knowledge, visuospatial ability, navigation through the field area, creating a mental model of the geology that is consistent with field data, and metacognition. Most post-secondary geology students in the United States receive training in geologic mapping, however, not much is known about the cognitive processes that underlie successful bedrock mapping, or about how these processes change with education and experience. To better understand cognition during geologic mapping, we conducted a 2-year research study in which 67 volunteers representing a range from undergraduate sophomore to 20+ years professional experience completed a suite of cognitive measures plus a 1-day bedrock mapping task in the Rocky Mountains, Montana, USA. In addition to participants' geologic maps and field notes, the cognitive suite included tests and questionnaires designed to measure: (1) prior geologic experience, via a self-report survey; (2) geologic content knowledge, via a modified version of the Geoscience Concept Inventory; (3) visuospatial ability, working memory capacity, and perceptual speed, via paper-and-pencil and computerized tests; (4) use of space and time during mapping via GPS tracking; and (5) problem-solving in the field via think-aloud audio logs during mapping and post-mapping semi-structured interviews. Data were examined for correlations between performance on the mapping task and other measures. We found that both geological knowledge and spatial visualization ability correlated positively with accuracy in the field mapping task. More importantly, we found a Visuospatial Ability × Geological Knowledge interaction, such that visuospatial ability positively predicted mapping performance at low, but not high, levels of geological knowledge. In other words, we found evidence to suggest that visuospatial ability mattered for bedrock mapping for the novices in our sample, but not for the experts. For experienced mappers, we found a significant correlation between GCI scores and the thoroughness with which they covered the map area, plus a relationship between speed and map accuracy such that faster mappers produced better maps. However, fast novice mappers tended to produce the worst maps. Successful mappers formed a mental model of the underlying geologic structure immediately to early in the mapping task, then spent field time collecting observations to confirm, disconfirm, or modify their initial model. In contrast, the least successful mappers (all inexperienced) rarely generated explanations or models of the underlying geologic structure in the field.

Familiarity and Recollection in Heuristic Decision Making

PubMed Central

Schwikert, Shane R.; Curran, Tim

2014-01-01

Heuristics involve the ability to utilize memory to make quick judgments by exploiting fundamental cognitive abilities. In the current study we investigated the memory processes that contribute to the recognition heuristic and the fluency heuristic, which are both presumed to capitalize on the by-products of memory to make quick decisions. In Experiment 1, we used a city-size comparison task while recording event-related potentials (ERPs) to investigate the potential contributions of familiarity and recollection to the two heuristics. ERPs were markedly different for recognition heuristic-based decisions and fluency heuristic-based decisions, suggesting a role for familiarity in the recognition heuristic and recollection in the fluency heuristic. In Experiment 2, we coupled the same city-size comparison task with measures of subjective pre-experimental memory for each stimulus in the task. Although previous literature suggests the fluency heuristic relies on recognition speed alone, our results suggest differential contributions of recognition speed and recollected knowledge to these decisions, whereas the recognition heuristic relies on familiarity. Based on these results, we created a new theoretical frame work that explains decisions attributed to both heuristics based on the underlying memory associated with the choice options. PMID:25347534

Familiarity and recollection in heuristic decision making.

PubMed

Schwikert, Shane R; Curran, Tim

2014-12-01

Heuristics involve the ability to utilize memory to make quick judgments by exploiting fundamental cognitive abilities. In the current study we investigated the memory processes that contribute to the recognition heuristic and the fluency heuristic, which are both presumed to capitalize on the byproducts of memory to make quick decisions. In Experiment 1, we used a city-size comparison task while recording event-related potentials (ERPs) to investigate the potential contributions of familiarity and recollection to the 2 heuristics. ERPs were markedly different for recognition heuristic-based decisions and fluency heuristic-based decisions, suggesting a role for familiarity in the recognition heuristic and recollection in the fluency heuristic. In Experiment 2, we coupled the same city-size comparison task with measures of subjective preexperimental memory for each stimulus in the task. Although previous literature suggests the fluency heuristic relies on recognition speed alone, our results suggest differential contributions of recognition speed and recollected knowledge to these decisions, whereas the recognition heuristic relies on familiarity. Based on these results, we created a new theoretical framework that explains decisions attributed to both heuristics based on the underlying memory associated with the choice options. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Motivations for speeding : traffic tech.

DOT National Transportation Integrated Search

2012-10-01

Speeding reduces a drivers ability to steer safely around : curves or objects in the roadway, extends the distance necessary : to stop a vehicle, and increases the distance a vehicle travels : while the driver reacts to a dangerous situation. Spee...

Energy absorption ability of buckyball C720 at low impact speed: a numerical study based on molecular dynamics

PubMed Central

2013-01-01

The dynamic impact response of giant buckyball C720 is investigated by using molecular dynamics simulations. The non-recoverable deformation of C720 makes it an ideal candidate for high-performance energy absorption. Firstly, mechanical behaviors under dynamic impact and low-speed crushing are simulated and modeled, which clarifies the buckling-related energy absorption mechanism. One-dimensional C720 arrays (both vertical and horizontal alignments) are studied at various impact speeds, which show that the energy absorption ability is dominated by the impact energy per buckyball and less sensitive to the number and arrangement direction of buckyballs. Three-dimensional stacking of buckyballs in simple cubic, body-centered cubic, hexagonal, and face-centered cubic forms are investigated. Stacking form with higher occupation density yields higher energy absorption. The present study may shed lights on employing C720 assembly as an advanced energy absorption system against low-speed impacts. PMID:23360618

Bilastine safety in drivers who need antihistamines: new evidence from high-speed simulator driving test on allergic patients.

PubMed

Demonte, A; Guanti, M B; Liberati, S; Biffi, A; Fernando, F; Fainello, M; Pepe, P

2018-02-01

Bilastine is a highly selective, non-sedating antihistamine, indicated for the symptomatic treatment of allergic rhinoconjunctivitis and urticaria. Available data suggest that bilastine interferes neither with driving ability nor with flying-related performance. However, no data are available on the effect of bilastine on the driving ability in extreme conditions. Here we analyzed the effect of 7 days treatment with 20 mg bilastine in patients with allergic rhinitis and/or chronic urticaria, on psychophysical performance assessed by the Formula One (F1) high-speed simulator-driving test. This study is a phase IV, interventional, prospective, mono-centric, single arm, open-label trial. Eighteen outpatients affected by allergic rhinitis and/or chronic urticaria, able to perform a preliminary driving test on F1 simulator were considered (V-1). First, the patients had a screening visit to assess their eligibility (V0). Visit 1 (V1), at the end of placebo before bilastine treatment and Visit 2 (V2), at the end of bilastine treatment. The primary variable parameter was the ability to maintain the vehicle in a central position at different speeds (50, 150, and 250 km/h). Bilastine had a good safety profile and was well tolerated in terms of adverse events, laboratory parameters and vital signs. Bilastine did not have any negative effect on the ability to maintain the requested path, a constant speed as well as on attention and reactivity levels, even in extreme driving conditions. This study is the first done in patients with allergic rhinitis and/or chronic urticaria using a F1-high speed simulator-driving test evaluating subjects' performance under bilastine treatment.

Importance of physical qualities for speed and change of direction ability in elite female soccer players.

PubMed

Emmonds, Stacey; Nicholson, G; Beggs, C; Jones, B; Bissas, A

2017-07-17

The purpose of this study was to determine the importance of physical qualities for speed and change of direction (CoD) ability in female soccer players. Data were collected on 10 female soccer players who were part of a professional English Women's Super League team. Player assessments included anthropometric (stature and body mass), body composition (dual-energy X-ray absorptiometry), speed (10m, 30m sprint), CoD ability (505 agility), aerobic (Yo-Yo Intermittent Recovery Test), lower-body strength (bilateral knee extensions) and power (countermovement jump [CMJ], squat jump [SJ], 30cm drop jump [DJ]) measures. The relationships between the variables were evaluated using eigenvector analysis and Pearson correlation analysis. Multiple linear regression revealed that the performance variables (10 and 20m speed, mean 505, and CoD deficit mean) can be predicted with almost 100% accuracy (i.e. adjusted R > 0.999) using various combinations of the predictor variables (DJ height, CMJ height, SJ height, lean body mass). An increase of one standard deviation (SD) in DJ height was associated with reductions of -5.636 and -9.082 SD in 10 m and 20 m sprint times. A one SD increase in CMJ also results in a reduction of -3.317 and -0.922 SD respectively in mean 505 and CoD deficit mean values. This study provides comparative data for professional English female soccer players that can be used by strength and conditioning coaches when monitoring player development and assessing the effectiveness of training programmes. Findings highlight the importance of developing reactive strength to improve speed and CoD ability in female soccer players.

Nonlinear optical microscopy for immunoimaging: a custom optimized system of high-speed, large-area, multicolor imaging

PubMed Central

Li, Hui; Cui, Quan; Zhang, Zhihong; Luo, Qingming

2015-01-01

Background The nonlinear optical microscopy has become the current state-of-the-art for intravital imaging. Due to its advantages of high resolution, superior tissue penetration, lower photodamage and photobleaching, as well as intrinsic z-sectioning ability, this technology has been widely applied in immunoimaging for a decade. However, in terms of monitoring immune events in native physiological environment, the conventional nonlinear optical microscope system has to be optimized for live animal imaging. Generally speaking, three crucial capabilities are desired, including high-speed, large-area and multicolor imaging. Among numerous high-speed scanning mechanisms used in nonlinear optical imaging, polygon scanning is not only linearly but also dispersion-freely with high stability and tunable rotation speed, which can overcome disadvantages of multifocal scanning, resonant scanner and acousto-optical deflector (AOD). However, low frame rate, lacking large-area or multicolor imaging ability make current polygonbased nonlinear optical microscopes unable to meet the requirements of immune event monitoring. Methods We built up a polygon-based nonlinear optical microscope system which was custom optimized for immunoimaging with high-speed, large-are and multicolor imaging abilities. Results Firstly, we validated the imaging performance of the system by standard methods. Then, to demonstrate the ability to monitor immune events, migration of immunocytes observed by the system based on typical immunological models such as lymph node, footpad and dorsal skinfold chamber are shown. Finally, we take an outlook for the possible advance of related technologies such as sample stabilization and optical clearing for more stable and deeper intravital immunoimaging. Conclusions This study will be helpful for optimizing nonlinear optical microscope to obtain more comprehensive and accurate information of immune events. PMID:25694951

Different cognitive functions discriminate gait performance in younger and older women: A pilot study.

PubMed

Gonzales, Joaquin U; James, C Roger; Yang, Hyung Suk; Jensen, Daniel; Atkins, Lee; Thompson, Brennan J; Al-Khalil, Kareem; O'Boyle, Michael

2016-10-01

Cognitive dysfunction is associated with slower gait speed in older women, but whether cognitive function affects gait performance earlier in life has yet to be investigated. Thus, the objective of this study was to test the hypothesis that cognitive function will discriminate gait performance in healthy younger women. Fast-pace and dual-task gait speed were measured in 30 young to middle-aged (30-45y) and 26 older (61-80y) women without mild cognitive impairment. Visuoperceptual ability, working memory, executive function, and learning ability were assessed using neuropsychological tests. Within each age group, women were divided by the median into lower and higher cognitive function groups to compare gait performance. Younger women with higher visuoperceptual ability had faster fast-pace (2.25±0.30 vs. 1.98±0.18m/s, p≤0.01) and dual-task gait speed (2.02±0.27 vs. 1.69±0.25m/s, p≤0.01) than women with lower visuoperceptual ability. The difference in dual-task gait speed remained significant (p=0.02) after adjusting for age, years of education, and other covariates. Dividing younger women based on other cognitive domains showed no difference in gait performance. In contrast, working memory and executive function discriminated dual-task gait speed (p<0.05) in older women after adjusting for age and education. To our knowledge, this is the first study to show that poorer cognitive function even at a relatively young age can negatively impact mobility. Different cognitive functions discriminated gait performance based on age, highlighting a possible influence of aging in the relationship between cognitive function and mobility in women. Copyright © 2016 Elsevier B.V. All rights reserved.

Relation between aerobic capacity and walking ability in older adults with a lower-limb amputation.

PubMed

Wezenberg, Daphne; van der Woude, Lucas H; Faber, Willemijn X; de Haan, Arnold; Houdijk, Han

2013-09-01

To determine the relative aerobic load, walking speed, and walking economy of older adults with a lower-limb prosthesis, and to predict the effect of an increased aerobic capacity on their walking ability. Cross-sectional. Human motion laboratory at a rehabilitation center. Convenience sample of older adults (n=36) who underwent lower-limb amputation because of vascular deficiency or trauma and able-bodied controls (n=21). Not applicable. Peak aerobic capacity and oxygen consumption while walking were determined. The relative aerobic load and walking economy were assessed as a function of walking speed, and a data-based model was constructed to predict the effect of an increased aerobic capacity on walking ability. People with a vascular amputation walked at a substantially higher (45.2%) relative aerobic load than people with an amputation because of trauma. The preferred walking speed in both groups of amputees was slower than that of able-bodied controls and below their most economical walking speed. We predicted that a 10% increase in peak aerobic capacity could potentially result in a reduction in the relative aerobic load of 9.1%, an increase in walking speed of 17.3% and 13.9%, and an improvement in the walking economy of 6.8% and 2.9%, for people after a vascular or traumatic amputation, respectively. Current findings corroborate the notion that, especially in people with a vascular amputation, the peak aerobic capacity is an important determinant for walking ability. The data provide quantitative predictions on the effect of aerobic training; however, future research is needed to experimentally confirm these predictions. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

An improved canopy wind model for predicting wind adjustment factors and wildland fire behavior

Treesearch

W. J. Massman; J. M. Forthofer; M. A. Finney

2017-01-01

The ability to rapidly estimate wind speed beneath a forest canopy or near the ground surface in any vegetation is critical to practical wildland fire behavior models. The common metric of this wind speed is the "mid-flame" wind speed, UMF. However, the existing approach for estimating UMF has some significant shortcomings. These include the assumptions that...

Can Response Speed Be Fixed Experimentally, and Does This Lead to Unconfounded Measurement of Ability?

ERIC Educational Resources Information Center

Bolsinova, Maria; Tijmstra, Jesper

2015-01-01

Goldhammer (this issue) proposes an interesting approach to dealing with the speededness of item responses. Rather than modeling speed as a latent variable that varies from person to person, he proposes to use experimental conditions that are expected to fix the speed, thereby eliminating individual differences on this dimension in order to make…

Intellectual Abilities That Discriminate Good and Poor Problem Solvers.

ERIC Educational Resources Information Center

Meyer, Ruth Ann

1981-01-01

This study compared good and poor fourth-grade problem solvers on a battery of 19 "reference" tests for verbal, induction, numerical, word fluency, memory, perceptual speed, and simple visualization abilities. Results suggest verbal, numerical, and especially induction abilities are important to successful mathematical problem solving.…

Experimental analysis of IMEP in a rotary combustion engine. [Indicated Mean Effective Pressure

NASA Technical Reports Server (NTRS)

Schock, H. J.; Rice, W. J.; Meng, P. R.

1981-01-01

This experimental work demonstrates the use of a NASA designed, real time Indicated Mean Effective Pressure (IMEP) measurement system which will be used to judge proposed improvements in cycle efficiency of a rotary combustion engine. This is the first self-contained instrument that is capable of making real time measurements of IMEP in a rotary engine. Previous methods used require data recording and later processing using a digital computer. The unique features of this instrumentation include its ability to measure IMEP on a cycle by cycle, real time basis and the elimination of the need to differentiate the volume function in real time. Measurements at two engine speeds (2000 and 3000 RPM) and a full range of loads are presented, although the instrument was designed to operate to speeds of 9000 RPM.

Enamel Insulated Copper Wire in Electric Motors: Sliding Behavior and Possible Damage Mechanisms During Die Bending

NASA Astrophysics Data System (ADS)

Demiri, Albion

This study investigates the sliding friction and the forming behaviour of enamel insulated copper wire during the die-forming process. It also aims to determine potential damage mechanisms to the wire during bending process for electric motor coils. In this investigation a wire-bending machine was designed and built in order to simulate the wire forming process in a laboratory scale. Bending angle of the wire and the bending radii were used to control the strain on the wire surface. The effect of speed on COF was investigated for different speeds of of 1, 5, 10, 15, and 20mm/s. A positive correlation was observed between the COF and the testing speed. Additionally, the effect of strain on COF was studied for 2% and 23% to determine its influence on the COF. A general trend was observed of decreased COF with increased strain in wires. Finally, the ability of the enamel coating to resist external damage and wire strain was investigated by tensile testing of pre-scratched magnet wire. The results showed that wire enamel can withstand significant surface damage prior to breach and failure. The insulating polymer coating failed under the scratch tests at 20N load using a Rockwell indenter and at 5N load using a 90° conical steel indenter. Additional tests, such as tensile testing, scratch testing and reciprocating friction testing, were used to characterize the mechanical and tribological properties of the enamel insulated copper wire.

The California Verbal Learning Test-Children's Version: relation to factor indices of the Wechsler Intelligence Scale for Children-Third Edition.

PubMed

O'Jile, Judith R; Schrimsher, Gregory W; O'Bryant, Sid E

2005-10-01

The California Verbal Learning Test-Children's Version (CVLT-C) provides clinicians with a method of assessing various aspects of children's verbal memory and has been found to be sensitive to memory deficits resulting from a variety of neurological conditions. Intuitively, the CVLT-C would be expected to be highly related to a child's verbal cognitive abilities; however, with only a few exceptions, the relationship of this test to various domains of cognitive function has not been broadly studied empirically. To examine this issue, we evaluated the amount of unique variance in CVLT-C scores that could be predicted by the Verbal Comprehension, Perceptual Organization, Freedom from Distractibility, and Processing Speed indices of the Wechsler Intelligence Scale for Children, Third Edition (WISC-III) beyond that accounted for by age and gender in a sample of 62 children referred to an outpatient psychiatry clinic for neuropsychological evaluation. While the Processing Speed Index predicted a significant amount of variance for both short and long delay free and cued recall, the Verbal Comprehension Index was a poor predictor of CVLT-C performance on all outcome variables, accounting for only 1.5 to 4.5% additional variance above age and gender. These findings indicate that while the CVLT-C may be relatively independent of influences of verbal intelligence and abstract verbal reasoning, general speed and efficiency of processing play an important role in successful encoding for later retrieval on the CVLT-C.

Recognition of tennis serve performed by a digital player: comparison among polygon, shadow, and stick-figure models.

PubMed

Ida, Hirofumi; Fukuhara, Kazunobu; Ishii, Motonobu

2012-01-01

The objective of this study was to assess the cognitive effect of human character models on the observer's ability to extract relevant information from computer graphics animation of tennis serve motions. Three digital human models (polygon, shadow, and stick-figure) were used to display the computationally simulated serve motions, which were perturbed at the racket-arm by modulating the speed (slower or faster) of one of the joint rotations (wrist, elbow, or shoulder). Twenty-one experienced tennis players and 21 novices made discrimination responses about the modulated joint and also specified the perceived swing speeds on a visual analogue scale. The result showed that the discrimination accuracies of the experienced players were both above and below chance level depending on the modulated joint whereas those of the novices mostly remained at chance or guessing levels. As far as the experienced players were concerned, the polygon model decreased the discrimination accuracy as compared with the stick-figure model. This suggests that the complicated pictorial information may have a distracting effect on the recognition of the observed action. On the other hand, the perceived swing speed of the perturbed motion relative to the control was lower for the stick-figure model than for the polygon model regardless of the skill level. This result suggests that the simplified visual information can bias the perception of the motion speed toward slower. It was also shown that the increasing the joint rotation speed increased the perceived swing speed, although the resulting racket velocity had little correlation with this speed sensation. Collectively, observer's recognition of the motion pattern and perception of the motion speed can be affected by the pictorial information of the human model as well as by the perturbation processing applied to the observed motion.

Gender effects on mental rotation in pilots vs. nonpilots.

PubMed

Verde, Paola; Piccardi, Laura; Bianchini, Filippo; Trivelloni, Pierandrea; Guariglia, Cecilia; Tomao, Enrico

2013-07-01

Mental rotation ability has an important role in human navigation and, together with other cognitive abilities such as processing speed, working memory, and attention, is crucial for aircraft navigation. In the human performance literature, mental rotation tasks have consistently yielded reports of gender differences favoring men. The aim of this study was to compare the gender difference measured in a specialized population of aviators vs. a matched population of nonpilots. : Studied were 41 pilots (20 men and 21 women) and 38 nonpilots (20 men and 18 women) matched for age and education. Pilots were stratified for flying hours. Participants performed a mental rotation task (MRT) in which accuracy and response time were recorded, and also completed sense-of-direction (SOD) and spatial cognitive styles self-evaluation scales. Men had significantly smaller response time in the MRT (men 279.6 +/- 147.0 s, women 401.6 +/- 361.3) and greater SOD (men's score 49.1 +/- 8.6, women's score 46.6 +/- 7.8), but these differences were absent among pilots. A positive relationship was also identified between pilots' response times and their flight hours. These data suggest that the effect of gender on the speed of cognitive spatial processing is absent in a population with aviation experience. Gender effects may be associated with a low spatial cognitive style, whereas in groups such as aviators, who are expected to have high spatial cognitive style, other factors such as experience may come into play.

The effect of strategic memory training in older adults: who benefits most?

PubMed

Rosi, Alessia; Del Signore, Federica; Canelli, Elisa; Allegri, Nicola; Bottiroli, Sara; Vecchi, Tomaso; Cavallini, Elena

2017-12-07

Previous research has suggested that there is a degree of variability among older adults' response to memory training, such that some individuals benefit more than others. The aim of the present study was to identify the profile of older adults who were likely to benefit most from a strategic memory training program that has previously proved to be effective in improving memory in healthy older adults. In total, 44 older adults (60-83 years) participated in a strategic memory training. We examined memory training benefits by measuring changes in memory practiced (word list learning) and non-practiced tasks (grocery list and associative learning). In addition, a battery of cognitive measures was administered in order to assess crystallized and fluid abilities, short-term memory, working memory, and processing speed. Results confirmed the efficacy of the training in improving performance in both practiced and non-practiced memory tasks. For the practiced memory tasks, results showed that memory baseline performance and crystallized ability predicted training gains. For the non-practiced memory tasks, analyses showed that memory baseline performance was a significant predictor of gain in the grocery list learning task. For the associative learning task, the significant predictors were memory baseline performance, processing speed, and marginally the age. Our results indicate that older adults with a higher baseline memory capacity and with more efficient cognitive resources were those who tended to benefit most from the training. The present study provides new avenues in designing personalized intervention according to the older adults' cognitive profile.

From specific examples to general knowledge in language learning.

PubMed

Tamminen, Jakke; Davis, Matthew H; Rastle, Kathleen

2015-06-01

The extraction of general knowledge from individual episodes is critical if we are to learn new knowledge or abilities. Here we uncover some of the key cognitive mechanisms that characterise this process in the domain of language learning. In five experiments adult participants learned new morphological units embedded in fictitious words created by attaching new affixes (e.g., -afe) to familiar word stems (e.g., "sleepafe is a participant in a study about the effects of sleep"). Participants' ability to generalise semantic knowledge about the affixes was tested using tasks requiring the comprehension and production of novel words containing a trained affix (e.g., sailafe). We manipulated the delay between training and test (Experiment 1), the number of unique exemplars provided for each affix during training (Experiment 2), and the consistency of the form-to-meaning mapping of the affixes (Experiments 3-5). In a task where speeded online language processing is required (semantic priming), generalisation was achieved only after a memory consolidation opportunity following training, and only if the training included a sufficient number of unique exemplars. Semantic inconsistency disrupted speeded generalisation unless consolidation was allowed to operate on one of the two affix-meanings before introducing inconsistencies. In contrast, in tasks that required slow, deliberate reasoning, generalisation could be achieved largely irrespective of the above constraints. These findings point to two different mechanisms of generalisation that have different cognitive demands and rely on different types of memory representations. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Morphological, motor and situation-motor characteristics of elite female handball players according to playing performance and position.

PubMed

Cavala, Marijana; Katić, Ratko

2010-12-01

The aim of the study was to define biomotor characteristics that determine playing performance and position in female handball. A battery of 13 variables consisting of somatotype components (3 variables), basic motor abilities (5 variables) and specific motor abilities (5 variables) were applied in a sample of 52 elite female handball players. Differences in biomotor characteristics according to playing performance and position of female handball players were determined by use of the analysis of variance (ANOVA) and discriminative analysis. Study results showed the high-quality female handball players to predominantly differ from the less successful ones in the specific factor of throw strength and basic dash factor, followed by the specific abilities of movement without and with ball, basic coordination/agility and specific ability of ball manipulation, and a more pronounced mesomorphic component. Results also revealed the wing players to be superior in the speed of movement frequency (psychomotor speed), run (explosive strength) and speed of movement with ball as compared with players at other playing positions. Also, endomorphic component was less pronounced in players at the wing and back player positions as compared with goalkeeper and pivot positions, where endomorphic component was considerably more pronounced.

Prefrontal cortex activity during response selection predicts processing speed impairment in schizophrenia

PubMed Central

Woodward, Neil D.; Duffy-Alberto, Brittney; Karbasforoushan, Haleh

2014-01-01

Processing speed is the most impaired neuropsychological domain in schizophrenia and a robust predictor of functional outcome. Determining the specific cognitive operations underlying processing speed dysfunction and indentifying their neural correlates may assist in developing pro-cognitive interventions. Response selection, the process of mapping stimuli onto motor responses, correlates with neuropsychological tests of processing speed and may contribute to processing speed impairment in schizophrenia. This study investigated the relationship between behavioral and neural measures of response selection, and a neuropsychological index of processing speed in schizophrenia. 26 patients with schizophrenia and 21 healthy subjects underwent fMRI scanning during performance of 2 and 4-choice-reaction time (RT) tasks and completed the Wechsler Adult Intelligence Scale-III (WAIS) Processing Speed Index (PSI). Response selection, defined as RT slowing between 2 and 4-choice RT, was impaired in schizophrenia and correlated with psychometric processing speed. Greater activation of the dorsolateral prefrontal cortex (PFC) was observed in schizophrenia and correlated with poorer WAIS PSI scores. Deficient response selection and abnormal recruitment of the dorsolateral PFC during response selection contribute to processing speed impairment in schizophrenia. Interventions that improve response selection and normalize dorsolateral PFC function may improve processing speed in schizophrenia. PMID:23816240

Working memory influences processing speed and reading fluency in ADHD.

PubMed

Jacobson, Lisa A; Ryan, Matthew; Martin, Rebecca B; Ewen, Joshua; Mostofsky, Stewart H; Denckla, Martha B; Mahone, E Mark

2011-01-01

Processing-speed deficits affect reading efficiency, even among individuals who recognize and decode words accurately. Children with ADHD who decode words accurately can still have inefficient reading fluency, leading to a bottleneck in other cognitive processes. This "slowing" in ADHD is associated with deficits in fundamental components of executive function underlying processing speed, including response selection. The purpose of the present study was to deconstruct processing speed in order to determine which components of executive control best explain the "processing" speed deficits related to reading fluency in ADHD. Participants (41 ADHD, 21 controls), ages 9-14 years, screened for language disorders, word reading deficits, and psychiatric disorders, were administered measures of copying speed, processing speed, reading fluency, working memory, reaction time, inhibition, and auditory attention span. Compared to controls, children with ADHD showed reduced oral and silent reading fluency and reduced processing speed-driven primarily by deficits on WISC-IV Coding. In contrast, groups did not differ on copying speed. After controlling for copying speed, sex, severity of ADHD-related symptomatology, and GAI, slowed "processing" speed (i.e., Coding) was significantly associated with verbal span and measures of working memory but not with measures of response control/inhibition, lexical retrieval speed, reaction time, or intrasubject variability. Further, "processing" speed (i.e., Coding, residualized for copying speed) and working memory were significant predictors of oral reading fluency. Abnormalities in working memory and response selection (which are frontally mediated and enter into the output side of processing speed) may play an important role in deficits in reading fluency in ADHD, potentially more than posteriorally mediated problems with orienting of attention or perceiving the stimulus.

Two-year changes in anthropometric and motor ability values as talent identification indexes in youth soccer players.

PubMed

Hirose, Norikazu; Seki, Taigo

2016-02-01

The present study examined 2-year changes in anthropometric variables and motor abilities in elite male youth soccer players to identify potential talent identification indexes. This was a cross-sequential study examining two different age groups at two time points. Height, weight, 40-m sprint speed, muscular power (5-step bounding), and change of direction (COD) ability (10 m×5 COD) were measured in 12- and 14-year-old soccer players and repeated after 2 years (at 14 and 16 years of age). Correlations and changes in ranking between the two measurements were determined. Both groups had small ranking changes in height (12-14-year-olds: r=0.80, 14-16-year-olds: r=0.89; p<0.01), weight (r=0.94, r=0.80; p<0.01), 40-m sprint speed (r=0.81, r=0.90; p<0.01), and muscular power (r=0.48, r=0.64; p<0.05), with a statistically significant correlation between the initial values and those obtained 2 years later. However, 10m×5 COD ability had a large ranking change, with no statistically significant correlation observed between the first- and second-year values. Because of the minimal ranking change in sprint speed in normal circumstances of soccer practice, linear sprint speed has the potential to be a useful talent identification index for youth soccer players. On the other hand, muscular power and COD ability is changeable during growth period suggests that these parameters is not useful for talent identification index. Copyright © 2015 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

A general high-speed laser drilling method for nonmetal thin material

NASA Astrophysics Data System (ADS)

Cai, Zhijian; Xu, Guangsheng; Xu, Zhou; Xu, Zhiqiang

2013-05-01

Many nonmetal film products, such as herbal plaster, medical adhesive tape and farm plastic film, require drilling dense small holes to enhance the permeability without affecting the appearance. For many medium and small enterprises, a low-cost, high-speed laser drilling machine with the ability of processing different kinds of nonmetal material is highly demanded. In this paper, we proposed a general purpose high-speed laser drilling method for micro-hole production on thin nonmetal film. The system utilizes a rotating polygonal mirror to perform high-speed laser scan, which is simpler and more efficient than the oscillating mirror scan. In this system, an array of closepacked paraboloid mirrors is mounted on the laser scan track to focus the high-power laser onto the material sheet, which could produce up to twenty holes in a single scan. The design of laser scan and focusing optics is optimized to obtain the best holes' quality, and the mirrors can be flexibly adjusted to get different drilling parameters. The use of rotating polygonal mirror scan and close-packed mirror array focusing greatly improves the drilling productivity to enable the machine producing thirty thousand holes per minute. With proper design, the hold uniformity can also get improved. In this paper, the detailed optical and mechanical design is illustrated, the high-speed laser drilling principle is introduced and the preliminary experimental results are presented.

Microeconomics of advanced process window control for 50-nm gates

NASA Astrophysics Data System (ADS)

Monahan, Kevin M.; Chen, Xuemei; Falessi, Georges; Garvin, Craig; Hankinson, Matt; Lev, Amir; Levy, Ady; Slessor, Michael D.

2002-07-01

Fundamentally, advanced process control enables accelerated design-rule reduction, but simple microeconomic models that directly link the effects of advanced process control to profitability are rare or non-existent. In this work, we derive these links using a simplified model for the rate of profit generated by the semiconductor manufacturing process. We use it to explain why and how microprocessor manufacturers strive to avoid commoditization by producing only the number of dies required to satisfy the time-varying demand in each performance segment. This strategy is realized using the tactic known as speed binning, the deliberate creation of an unnatural distribution of microprocessor performance that varies according to market demand. We show that the ability of APC to achieve these economic objectives may be limited by variability in the larger manufacturing context, including measurement delays and process window variation.

Real-time implementing wavefront reconstruction for adaptive optics

NASA Astrophysics Data System (ADS)

Wang, Caixia; Li, Mei; Wang, Chunhong; Zhou, Luchun; Jiang, Wenhan

2004-12-01

The capability of real time wave-front reconstruction is important for an adaptive optics (AO) system. The bandwidth of system and the real-time processing ability of the wave-front processor is mainly affected by the speed of calculation. The system requires enough number of subapertures and high sampling frequency to compensate atmospheric turbulence. The number of reconstruction operation is increased accordingly. Since the performance of AO system improves with the decrease of calculation latency, it is necessary to study how to increase the speed of wavefront reconstruction. There are two methods to improve the real time of the reconstruction. One is to convert the wavefront reconstruction matrix, such as by wavelet or FFT. The other is enhancing the performance of the processing element. Analysis shows that the latency cutting is performed with the cost of reconstruction precision by the former method. In this article, the latter method is adopted. From the characteristic of the wavefront reconstruction algorithm, a systolic array by FPGA is properly designed to implement real-time wavefront reconstruction. The system delay is reduced greatly by the utilization of pipeline and parallel processing. The minimum latency of reconstruction is the reconstruction calculation of one subaperture.

Speeding-Related Multi-Vehicle Fatal Crashes Involving Large Trucks

DOT National Transportation Integrated Search

1999-12-01

Speeding reduces a drivers ability to steer safely around curves or objects in the roadway, extends the distance necessary to stop a vehicle, and increases the distance a vehicle travels while the driver reacts to a dangerous situation. The danger...

Swimming Performance and Metabolism of Golden Shiners

USDA-ARS?s Scientific Manuscript database

The swimming ability and metabolism of golden shiners, Notemigonus crysoleucas, was examined using swim tunnel respirometery. The oxygen consumption and tail beat frequencies at various swimming speeds, an estimation of the standard metabolic rate, and the critical swimming speed (Ucrit) was determ...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, Yi; Cai, Zhonghou; Chen, Pice

Dynamical phase separation during a solid-solid phase transition poses a challenge for understanding the fundamental processes in correlated materials. Critical information underlying a phase transition, such as localized phase competition, is difficult to reveal by measurements that are spatially averaged over many phase seperated regions. The ability to simultanousely track the spatial and temporal evolution of such systems is essential to understanding mesoscopic processes during a phase transition. Using state-of- the-art time-resolved hard x-ray diffraction microscopy, we directly visualize the structural phase progression in a VO 2 film upon photoexcitation. Following a homogenous in-plane optical excitation, the phase transformation ismore » initiated at discrete sites and completed by the growth of one lattice structure into the other, instead of a simultaneous isotropic lattice symmetry change. The time-dependent x-ray diffraction spatial maps show that the in-plane phase progression in laser-superheated VO 2 is via a displacive lattice transformation as a result of relaxation from an excited monoclinic phase into a rutile phase. The speed of the phase front progression is quantitatively measured, which is faster than the process driven by in-plane thermal diffusion but slower than the sound speed in VO 2. Lastly, the direct visualization of localized structural changes in the time domain opens a new avenue to study mesoscopic processes in driven systems.« less

Toolpath Strategy and Optimum Combination of Machining Parameter during Pocket Mill Process of Plastic Mold Steels Material

NASA Astrophysics Data System (ADS)

Wibowo, Y. T.; Baskoro, S. Y.; Manurung, V. A. T.

2018-02-01

Plastic based products spread all over the world in many aspects of life. The ability to substitute other materials is getting stronger and wider. The use of plastic materials increases and become unavoidable. Plastic based mass production requires injection process as well Mold. The milling process of plastic mold steel material was done using HSS End Mill cutting tool that is widely used in a small and medium enterprise for the reason of its ability to be re sharpened and relatively inexpensive. Study on the effect of the geometry tool states that it has an important effect on the quality improvement. Cutting speed, feed rate, depth of cut and radii are input parameters beside to the tool path strategy. This paper aims to investigate input parameter and cutting tools behaviors within some different tool path strategy. For the reason of experiments efficiency Taguchi method and ANOVA were used. Response studied is surface roughness and cutting behaviors. By achieving the expected quality, no more additional process is required. Finally, the optimal combination of machining parameters will deliver the expected roughness and of course totally reduced cutting time. However actually, SMEs do not optimally use this data for cost reduction.

Applying shot boundary detection for automated crystal growth analysis during in situ transmission electron microscope experiments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moeglein, W. A.; Griswold, R.; Mehdi, B. L.

In-situ (scanning) transmission electron microscopy (S/TEM) is being developed for numerous applications in the study of nucleation and growth under electrochemical driving forces. For this type of experiment, one of the key parameters is to identify when nucleation initiates. Typically the process of identifying the moment that crystals begin to form is a manual process requiring the user to perform an observation and respond accordingly (adjust focus, magnification, translate the stage etc.). However, as the speed of the cameras being used to perform these observations increases, the ability of a user to “catch” the important initial stage of nucleation decreasesmore » (there is more information that is available in the first few milliseconds of the process). Here we show that video shot boundary detection (SBD) can automatically detect frames where a change in the image occurs. We show that this method can be applied to quickly and accurately identify points of change during crystal growth. This technique allows for automated segmentation of a digital stream for further analysis and the assignment of arbitrary time stamps for the initiation of processes that are independent of the user’s ability to observe and react.« less

Multimodal imaging of the self-regulating developing brain.

PubMed

Fjell, Anders M; Walhovd, Kristine Beate; Brown, Timothy T; Kuperman, Joshua M; Chung, Yoonho; Hagler, Donald J; Venkatraman, Vijay; Roddey, J Cooper; Erhart, Matthew; McCabe, Connor; Akshoomoff, Natacha; Amaral, David G; Bloss, Cinnamon S; Libiger, Ondrej; Darst, Burcu F; Schork, Nicholas J; Casey, B J; Chang, Linda; Ernst, Thomas M; Gruen, Jeffrey R; Kaufmann, Walter E; Kenet, Tal; Frazier, Jean; Murray, Sarah S; Sowell, Elizabeth R; van Zijl, Peter; Mostofsky, Stewart; Jernigan, Terry L; Dale, Anders M

2012-11-27

Self-regulation refers to the ability to control behavior, cognition, and emotions, and self-regulation failure is related to a range of neuropsychiatric problems. It is poorly understood how structural maturation of the brain brings about the gradual improvement in self-regulation during childhood. In a large-scale multicenter effort, 735 children (4-21 y) underwent structural MRI for quantification of cortical thickness and surface area and diffusion tensor imaging for quantification of the quality of major fiber connections. Brain development was related to a standardized measure of cognitive control (the flanker task from the National Institutes of Health Toolbox), a critical component of self-regulation. Ability to inhibit responses and impose cognitive control increased rapidly during preteen years. Surface area of the anterior cingulate cortex accounted for a significant proportion of the variance in cognitive performance. This finding is intriguing, because characteristics of the anterior cingulum are shown to be related to impulse, attention, and executive problems in neurodevelopmental disorders, indicating a neural foundation for self-regulation abilities along a continuum from normality to pathology. The relationship was strongest in the younger children. Properties of large-fiber connections added to the picture by explaining additional variance in cognitive control. Although cognitive control was related to surface area of the anterior cingulate independently of basic processes of mental speed, the relationship between white matter quality and cognitive control could be fully accounted for by speed. The results underscore the need for integration of different aspects of brain maturation to understand the foundations of cognitive development.

A novel digital neutron flux monitor for international thermonuclear experimental reactor

NASA Astrophysics Data System (ADS)

Xiang, ZHOU; Zihao, LIU; Chao, CHEN; Renjie, ZHU; Li, ZHAO; Lingfeng, WEI; Zejie, YIN

2018-04-01

A novel full-digital real-time neutron flux monitor (NFM) has been developed for the International Thermonuclear Experimental Reactor. A measurement range of 109 counts per second is achieved with 3 different sensitive fission chambers. The Counting mode and Campbelling mode have been combined as a means to achieve higher measurement range. The system is based on high speed as well as parallel and pipeline processing of the field programmable gate array and has the ability to upload raw-data of analog-to-digital converter in real-time through the PXIe platform. With the advantages of the measurement range, real time performance and the ability of raw-data uploading, the digital NFM has been tested in HL-2A experiments and reflected good experimental performance.

Dynamics of Nanoscale Grain-Boundary Decohesion in Aluminum by Molecular-Dynamics Simulation

NASA Technical Reports Server (NTRS)

Yamakov, V.; Saether, E.; Phillips, D. R.; Glaessegen, E. H.

2007-01-01

The dynamics and energetics of intergranular crack growth along a flat grain boundary in aluminum is studied by a molecular-dynamics simulation model for crack propagation under steady-state conditions. Using the ability of the molecular-dynamics simulation to identify atoms involved in different atomistic mechanisms, it was possible to identify the energy contribution of different processes taking place during crack growth. The energy contributions were divided as: elastic energy, defined as the potential energy of the atoms in fcc crystallographic state; and plastically stored energy, the energy of stacking faults and twin boundaries; grain-boundary and surface energy. In addition, monitoring the amount of heat exchange with the molecular-dynamics thermostat gives the energy dissipated as heat in the system. The energetic analysis indicates that the majority of energy in a fast growing crack is dissipated as heat. This dissipation increases linearly at low speed, and faster than linear at speeds approaching 1/3 the Rayleigh wave speed when the crack tip becomes dynamically unstable producing periodic dislocation bursts until the crack is blunted.

Deficiency in Mental Rotation of Upper and Lower-Limbs in Patients With Multiple Sclerosis and Its Relation With Cognitive Functions.

PubMed

Azin, Mahdieh; Zangiabadi, Nasser; Moghadas Tabrizi, Yousef; Iranmanesh, Farhad; Baneshi, Mohammad Reza

2016-08-01

Mental rotation is a cognitive motor process which was impaired in different neurologic disorders. We investigated whether there were deficits in response pattern, reaction time and response accuracy rate of mental rotation in multiple sclerosis (MS) patients compared to healthy subjects and whether cognitive dysfunctions in MS patients were correlated with mental rotation deficits. Moreover, we showed whether there was a difference between upper and lower-limbs mental rotation in MS patients. Thirty-five MS patients and 25 healthy subjects performed hand mental rotation (HMR) and foot mental rotation (FMR) tasks. Visual information processing speed, spatial learning and memory ability, and visuospatial processing were assessed by Symbol Digit Modalities Test (SDMT), Brief Visuospatial Memory Test-Revised (BVMT-R), and Judgment of Line Orientation Test (JLO) respectively in MS patients. Reaction time for both hand and foot stimuli increased, and response accuracy rate for hand stimuli decreased in MS patients compared to healthy subjects, but response pattern of mental rotation in MS patients persisted. Similar to healthy subjects, MS patients performed upper-limbs mental rotation more easily than a lower-limbs mental rotation with more speed and response accuracy rate. Reaction time and response accuracy rate were correlated with the mentioned cognitive functions. MS patients made use of the correct response pattern for problem solving of increasing orientation from upright stimuli. Reaction time and response accuracy rate altered in these patients and this alteration might occur along with impairment in motor planning. Subjects' better responding to hand stimuli was due to more familiarity with hand stimuli. The correlation of mental rotation ability with cognitive functions indicates the possible role of cognitive functions in mental rotation.

Interpretation of medical imaging data with a mobile application: a mobile digital imaging processing environment.

PubMed

Lin, Meng Kuan; Nicolini, Oliver; Waxenegger, Harald; Galloway, Graham J; Ullmann, Jeremy F P; Janke, Andrew L

2013-01-01

Digital Imaging Processing (DIP) requires data extraction and output from a visualization tool to be consistent. Data handling and transmission between the server and a user is a systematic process in service interpretation. The use of integrated medical services for management and viewing of imaging data in combination with a mobile visualization tool can be greatly facilitated by data analysis and interpretation. This paper presents an integrated mobile application and DIP service, called M-DIP. The objective of the system is to (1) automate the direct data tiling, conversion, pre-tiling of brain images from Medical Imaging NetCDF (MINC), Neuroimaging Informatics Technology Initiative (NIFTI) to RAW formats; (2) speed up querying of imaging measurement; and (3) display high-level of images with three dimensions in real world coordinates. In addition, M-DIP provides the ability to work on a mobile or tablet device without any software installation using web-based protocols. M-DIP implements three levels of architecture with a relational middle-layer database, a stand-alone DIP server, and a mobile application logic middle level realizing user interpretation for direct querying and communication. This imaging software has the ability to display biological imaging data at multiple zoom levels and to increase its quality to meet users' expectations. Interpretation of bioimaging data is facilitated by an interface analogous to online mapping services using real world coordinate browsing. This allows mobile devices to display multiple datasets simultaneously from a remote site. M-DIP can be used as a measurement repository that can be accessed by any network environment, such as a portable mobile or tablet device. In addition, this system and combination with mobile applications are establishing a virtualization tool in the neuroinformatics field to speed interpretation services.

Interpretation of Medical Imaging Data with a Mobile Application: A Mobile Digital Imaging Processing Environment

PubMed Central

Lin, Meng Kuan; Nicolini, Oliver; Waxenegger, Harald; Galloway, Graham J.; Ullmann, Jeremy F. P.; Janke, Andrew L.

2013-01-01

Digital Imaging Processing (DIP) requires data extraction and output from a visualization tool to be consistent. Data handling and transmission between the server and a user is a systematic process in service interpretation. The use of integrated medical services for management and viewing of imaging data in combination with a mobile visualization tool can be greatly facilitated by data analysis and interpretation. This paper presents an integrated mobile application and DIP service, called M-DIP. The objective of the system is to (1) automate the direct data tiling, conversion, pre-tiling of brain images from Medical Imaging NetCDF (MINC), Neuroimaging Informatics Technology Initiative (NIFTI) to RAW formats; (2) speed up querying of imaging measurement; and (3) display high-level of images with three dimensions in real world coordinates. In addition, M-DIP provides the ability to work on a mobile or tablet device without any software installation using web-based protocols. M-DIP implements three levels of architecture with a relational middle-layer database, a stand-alone DIP server, and a mobile application logic middle level realizing user interpretation for direct querying and communication. This imaging software has the ability to display biological imaging data at multiple zoom levels and to increase its quality to meet users’ expectations. Interpretation of bioimaging data is facilitated by an interface analogous to online mapping services using real world coordinate browsing. This allows mobile devices to display multiple datasets simultaneously from a remote site. M-DIP can be used as a measurement repository that can be accessed by any network environment, such as a portable mobile or tablet device. In addition, this system and combination with mobile applications are establishing a virtualization tool in the neuroinformatics field to speed interpretation services. PMID:23847587

Test Anxiety Among College Students With Specific Reading Disability (Dyslexia): Nonverbal Ability and Working Memory as Predictors.

PubMed

Nelson, Jason M; Lindstrom, Will; Foels, Patricia A

2015-01-01

Test anxiety and its correlates were examined with college students with and without specific reading disability (RD; n = 50 in each group). Results indicated that college students with RD reported higher test anxiety than did those without RD, and the magnitude of these differences was in the medium range on two test anxiety scales. Relative to college students without RD, up to 5 times as many college students with RD reported clinically significant test anxiety. College students with RD reported significantly higher cognitively based test anxiety than physically based test anxiety. Reading skills, verbal ability, and processing speed were not correlated with test anxiety. General intelligence, nonverbal ability, and working memory were negatively correlated with test anxiety, and the magnitude of these correlations was medium to large. When these three cognitive constructs were considered together in multiple regression analyses, only working memory and nonverbal ability emerged as significant predictors and varied based on the test anxiety measure. Implications for assessment and intervention are discussed. © Hammill Institute on Disabilities 2013.

A comprehensive assessment of cognitive function in the common genetic generalized epilepsy syndromes.

PubMed

Loughman, A; Bowden, S C; D'Souza, W J

2017-03-01

Considered to be benign conditions, the common genetic generalized epilepsy (GGE) syndromes are now known to be frequently accompanied by cognitive dysfunction. However, unresolved issues impede clinical management of this common comorbidity, including which cognitive abilities are most affected, whether there are differences between syndromes and how seizure type and mood symptoms affect cognitive dysfunction. We provide a detailed description of cognitive ability and evaluate factors contributing to cognitive dysfunction. A total of 76 adults with GGE were assessed with the Woodcock Johnson III Tests of Cognitive Abilities. Scores on tests of overall cognitive ability, acquired knowledge, long-term retrieval and speed of information processing were significantly below the normative mean. Long-term retrieval was a pronounced weakness with a large reduction in scores (d = 0.84). GGE syndrome, seizure type and the presence of recent psychopathology symptoms were not significantly associated with cognitive function. This study confirms previous meta-analytic findings with a prospective study, offers new insights into the cognitive comorbidity of these common epilepsy syndromes and reinforces the need for cognitive interventions in people with GGE. © 2016 EAN.

Intrinsic Functional Connectivity in the Adult Brain and Success in Second-Language Learning.

PubMed

Chai, Xiaoqian J; Berken, Jonathan A; Barbeau, Elise B; Soles, Jennika; Callahan, Megan; Chen, Jen-Kai; Klein, Denise

2016-01-20

There is considerable variability in an individual's ability to acquire a second language (L2) during adulthood. Using resting-state fMRI data acquired before training in English speakers who underwent a 12 week intensive French immersion training course, we investigated whether individual differences in intrinsic resting-state functional connectivity relate to a person's ability to acquire an L2. We focused on two key aspects of language processing--lexical retrieval in spontaneous speech and reading speed--and computed whole-brain functional connectivity from two regions of interest in the language network, namely the left anterior insula/frontal operculum (AI/FO) and the visual word form area (VWFA). Connectivity between the left AI/FO and left posterior superior temporal gyrus (STG) and between the left AI/FO and dorsal anterior cingulate cortex correlated positively with improvement in L2 lexical retrieval in spontaneous speech. Connectivity between the VWFA and left mid-STG correlated positively with improvement in L2 reading speed. These findings are consistent with the different language functions subserved by subcomponents of the language network and suggest that the human capacity to learn an L2 can be predicted by an individual's intrinsic functional connectivity within the language network. Significance statement: There is considerable variability in second-language learning abilities during adulthood. We investigated whether individual differences in intrinsic functional connectivity in the adult brain relate to success in second-language learning, using resting-state functional magnetic resonance imaging in English speakers who underwent a 12 week intensive French immersion training course. We found that pretraining functional connectivity within two different language subnetworks correlated strongly with learning outcome in two different language skills: lexical retrieval in spontaneous speech and reading speed. Our results suggest that the human capacity to learn a second language can be predicted by an individual's intrinsic functional connectivity within the language network. Copyright © 2016 the authors 0270-6474/16/360755-07$15.00/0.

The relationship between Big-5 personality traits and cognitive ability in older adults - a review.

PubMed

Curtis, Rachel G; Windsor, Tim D; Soubelet, Andrea

2015-01-01

It is well established that fundamental aspects of cognition such as memory and speed of processing tend to decline with age; however, there is substantial between-individual variability in levels of cognitive performance in older adulthood and in rates of change in cognitive abilities over time. Recent years have seen an increasing number of studies concerned with examining personality characteristics as possible predictors of some of this variability in cognitive aging. The purpose of this article is to review the literature, and identify patterns of findings regarding the relationships between personality (focusing on the Big-5) and cognitive ability across nonclinical populations of older adults. Possible mechanisms underlying associations of personality characteristics with cognition are reviewed, and assessed in the context of the current literature. Some relatively consistent relationships are identified, including positive associations between openness and cognitive ability, and associations of conscientiousness with slower rates of cognitive decline. However, the relationships between several personality traits and cognitive abilities in older adults remain unclear. We suggest some approaches to research design and analysis that may help increase our understanding of how personality differences may contribute to cognitive aging.

Normative Data on Audiovisual Speech Integration Using Sentence Recognition and Capacity Measures

PubMed Central

Altieri, Nicholas; Hudock, Daniel

2016-01-01

Objective The ability to use visual speech cues and integrate them with auditory information is important, especially in noisy environments and for hearing-impaired (HI) listeners. Providing data on measures of integration skills that encompass accuracy and processing speed will benefit researchers and clinicians. Design The study consisted of two experiments: First, accuracy scores were obtained using CUNY sentences, and capacity measures that assessed reaction-time distributions were obtained from a monosyllabic word recognition task. Study Sample We report data on two measures of integration obtained from a sample comprised of 86 young and middle-age adult listeners: Results To summarize our results, capacity showed a positive correlation with accuracy measures of audiovisual benefit obtained from sentence recognition. More relevant, factor analysis indicated that a single-factor model captured audiovisual speech integration better than models containing more factors. Capacity exhibited strong loadings on the factor, while the accuracy-based measures from sentence recognition exhibited weaker loadings. Conclusions Results suggest that a listener’s integration skills may be assessed optimally using a measure that incorporates both processing speed and accuracy. PMID:26853446

Normative data on audiovisual speech integration using sentence recognition and capacity measures.

PubMed

Altieri, Nicholas; Hudock, Daniel

2016-01-01

The ability to use visual speech cues and integrate them with auditory information is important, especially in noisy environments and for hearing-impaired (HI) listeners. Providing data on measures of integration skills that encompass accuracy and processing speed will benefit researchers and clinicians. The study consisted of two experiments: First, accuracy scores were obtained using City University of New York (CUNY) sentences, and capacity measures that assessed reaction-time distributions were obtained from a monosyllabic word recognition task. We report data on two measures of integration obtained from a sample comprised of 86 young and middle-age adult listeners: To summarize our results, capacity showed a positive correlation with accuracy measures of audiovisual benefit obtained from sentence recognition. More relevant, factor analysis indicated that a single-factor model captured audiovisual speech integration better than models containing more factors. Capacity exhibited strong loadings on the factor, while the accuracy-based measures from sentence recognition exhibited weaker loadings. Results suggest that a listener's integration skills may be assessed optimally using a measure that incorporates both processing speed and accuracy.

Correlations between Berg balance scale and gait speed in individuals with stroke wearing ankle-foot orthoses - a pilot study.

PubMed

Kobayashi, Toshiki; Leung, Aaron K L; Akazawa, Yasushi; Hutchins, Stephen W

2016-01-01

The Berg balance scale (BBS) is commonly used to assess balancing ability in patients with stroke. The BBS may be a good candidate for clinical assessment prior to orthotic intervention, if it correlates well with outcome measures such as gait speed. The purpose of this study was to investigate the correlation between the BBS measured prior to walking with an ankle-foot orthosis (AFO) and specific temporal-spatial parameters of gait when walking with an AFO donned. Eight individuals with chronic stroke participated in this study. Balancing ability was assessed using the BBS, while temporal-spatial parameters of gait (gait speed, bilateral step length, stride length and step width) were measured using a three-dimensional motion analysis system. The correlations between the BBS and gait parameters were investigated using a non-parametric Kendall's Tau (τ) correlation analysis. The BBS showed correlations with gait speed (τ = 0.64, p < 0.05), the step length of the affected side (τ = 0.74, p < 0.05), and the stride length (τ = 0.64, p < 0.05). Assessment of the BBS prior to AFO prescription may potentially help clinicians to estimate the gait speed achievable following orthotic intervention in patients with stroke. Implications for Rehabilitation Assessment of the BBS prior to AFO prescription may help orthotists to estimate the gait speed following an orthotic intervention in patients with stroke. Assessment of the BBS prior to AFO prescription may help orthotists to understand overall balance and postural control abilities in patients with stroke. A larger scale multifactorial analysis is warranted to confirm the results of this pilot study.

Speeding up parallel processing

NASA Technical Reports Server (NTRS)

Denning, Peter J.

1988-01-01

In 1967 Amdahl expressed doubts about the ultimate utility of multiprocessors. The formulation, now called Amdahl's law, became part of the computing folklore and has inspired much skepticism about the ability of the current generation of massively parallel processors to efficiently deliver all their computing power to programs. The widely publicized recent results of a group at Sandia National Laboratory, which showed speedup on a 1024 node hypercube of over 500 for three fixed size problems and over 1000 for three scalable problems, have convincingly challenged this bit of folklore and have given new impetus to parallel scientific computing.

Memory skills of deaf learners: implications and applications.

PubMed

Hamilton, Harley

2011-01-01

The author reviews research on working memory and short-term memory abilities of deaf individuals, delineating strengths and weaknesses. Among the areas of weakness that are reviewed are sequential recall, processing speed, attention, and memory load. Areas of strengths include free recall, visuospatial recall, imagery, and dual encoding. Phonological encoding and rehearsal appear to be strengths when these strategies are employed. The implications of the strengths and weaknesses for language learning and educational achievement are discussed. Research questions are posed, and remedial and compensatory classroom applications are suggested.

The difference engine: a model of diversity in speeded cognition.

PubMed

Myerson, Joel; Hale, Sandra; Zheng, Yingye; Jenkins, Lisa; Widaman, Keith F

2003-06-01

A theory of diversity in speeded cognition, the difference engine, is proposed, in which information processing is represented as a series of generic computational steps. Some individuals tend to perform all of these computations relatively quickly and other individuals tend to perform them all relatively slowly, reflecting the existence of a general cognitive speed factor, but the time required for response selection and execution is assumed to be independent of cognitive speed. The difference engine correctly predicts the positively accelerated form of the relation between diversity of performance, as measured by the standard deviation for the group, and task difficulty, as indexed by the mean response time (RT) for the group. In addition, the difference engine correctly predicts approximately linear relations between the RTs of any individual and average performance for the group, with the regression lines for fast individuals having slopes less than 1.0 (and positive intercepts) and the regression lines for slow individuals having slopes greater than 1.0 (and negative intercepts). Similar predictions are made for comparisons of slow, average, and fast subgroups, regardless of whether those subgroups are formed on the basis of differences in ability, age, or health status. These predictions are consistent with evidence from studies of healthy young and older adults as well as from studies of depressed and age-matched control groups.

Submerged arc welding of heavy plate

NASA Technical Reports Server (NTRS)

Wilson, R. A.

1972-01-01

The submerged arc process is particularly suitable for heavy plate welding because of its ability to combine very high deposit rates along with excellent quality. It does these things without the smoke and spatter often accompanying other processes. It is available today in several forms that are pointed to the fabricators of heavy sections with long, short or round about welds. Tandem arc full automatic equipment is particularly suitable for those long heavy welds where speed and deposit rate are of the first order. An attachment called long stick-out which makes use of the IR drop on long electrode extensions can be included on this equipment to increase deposition rates 50% or more.

The Role of Cognitive Abilities in Laparoscopic Simulator Training

ERIC Educational Resources Information Center

Groenier, M.; Schraagen, J. M. C.; Miedema, H. A. T.; Broeders, I. A. J. M.

2014-01-01

Learning minimally invasive surgery (MIS) differs substantially from learning open surgery and trainees differ in their ability to learn MIS. Previous studies mainly focused on the role of visuo-spatial ability (VSA) on the learning curve for MIS. In the current study, the relationship between spatial memory, perceptual speed, and general…

Deconstructing processing speed deficits in schizophrenia: application of a parametric digit symbol coding test.

PubMed

Bachman, Peter; Reichenberg, Abraham; Rice, Patrick; Woolsey, Mary; Chaves, Olga; Martinez, David; Maples, Natalie; Velligan, Dawn I; Glahn, David C

2010-05-01

Cognitive processing inefficiency, often measured using digit symbol coding tasks, is a putative vulnerability marker for schizophrenia and a reliable indicator of illness severity and functional outcome. Indeed, performance on the digit symbol coding task may be the most severe neuropsychological deficit patients with schizophrenia display at the group level. Yet, little is known about the contributions of simpler cognitive processes to coding performance in schizophrenia (e.g. decision making, visual scanning, relational memory, motor ability). We developed an experimental behavioral task, based on a computerized digit symbol coding task, which allows the manipulation of demands placed on visual scanning efficiency and relational memory while holding decisional and motor requirements constant. Although patients (n=85) were impaired on all aspects of the task when compared to demographically matched healthy comparison subjects (n=30), they showed a particularly striking failure to benefit from the presence of predictable target information. These findings are consistent with predicted impairments in cognitive processing speed due to schizophrenia patients' well-known memory impairment, suggesting that this mnemonic deficit may have consequences for critical aspects of information processing that are traditionally considered quite separate from the memory domain. Future investigation into the mechanisms underlying the wide-ranging consequences of mnemonic deficits in schizophrenia should provide additional insight. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Effects of Speed and Grade Change on the Ability to Reproduce a Standard Work Effort

ERIC Educational Resources Information Center

Michael, Ernest D., Jr.; Katch, Victor

1977-01-01

While running up an incline at a speed chosen by themselves, subjects apparently will perceive the work effort to be the same as running on the level, when in fact it is costing them more energy. (MM)

Impact of Perceptual Speed Calming Curve Countermeasures on Drivers’ Anticipation and Mitigation Ability : A Driving Simulator Study

DOT National Transportation Integrated Search

2018-02-01

Horizontal curves are unavoidable in rural roads and are a serious crash risk to vehicle occupants. This study investigates the impact and effectiveness of three curve-based perceptual speed-calming countermeasures (advance curve warning signs, chevr...

What Are You Measuring? Dimensionality and Reliability Analysis of Ability and Speed in Medical School Didactic Examinations.

PubMed

Thompson, James J

2016-01-01

Summative didactic evaluation often involves multiple choice questions which are then aggregated into exam scores, course scores, and cumulative grade point averages. To be valid, each of these levels should have some relationship to the topic tested (dimensionality) and be sufficiently reproducible between persons (reliability) to justify student ranking. Evaluation of dimensionality is difficult and is complicated by the classic observation that didactic performance involves a generalized component (g) in addition to subtest specific factors. In this work, 183 students were analyzed over two academic years in 13 courses with 44 exams and 3352 questions for both accuracy and speed. Reliability at all levels was good (>0.95). Assessed by bifactor analysis, g effects dominated most levels resulting in essential unidimensionality. Effect sizes on predicted accuracy and speed due to nesting in exams and courses was small. There was little relationship between person ability and person speed. Thus, the hierarchical grading system appears warrented because of its g-dependence.

Fronto-Parietal Network Reconfiguration Supports the Development of Reasoning Ability.

PubMed

Wendelken, Carter; Ferrer, Emilio; Whitaker, Kirstie J; Bunge, Silvia A

2016-05-01

The goal of this fMRI study was to examine how well developmental improvements in reasoning ability can be explained by changes in functional connectivity between specific nodes in prefrontal and parietal cortices. To this end, we examined connectivity within the lateral fronto-parietal network (LFPN) and its relation to reasoning ability in 132 children and adolescents aged 6-18 years, 56 of whom were scanned twice over the course of 1.5 years. Developmental changes in strength of connections within the LFPN were most prominent in late childhood and early adolescence. Reasoning ability was related to functional connectivity between left rostrolateral prefrontal cortex (RLPFC) and inferior parietal lobule (IPL), but only among 12-18-year olds. For 9-11-year olds, reasoning ability was most strongly related to connectivity between left and right RLPFC; this relationship was mediated by working memory. For 6-8-year olds, significant relationships between connectivity and performance were not observed; in this group, processing speed was the primary mediator of improvement in reasoning ability. We conclude that different connections best support reasoning at different points in development and that RLPFC-IPL connectivity becomes an important predictor of reasoning during adolescence. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Brain white matter damage in aging and cognitive ability in youth and older age.

PubMed

Valdés Hernández, Maria Del C; Booth, Tom; Murray, Catherine; Gow, Alan J; Penke, Lars; Morris, Zoe; Maniega, Susana Muñoz; Royle, Natalie A; Aribisala, Benjamin S; Bastin, Mark E; Starr, John M; Deary, Ian J; Wardlaw, Joanna M

2013-12-01

Cerebral white matter hyperintensities (WMH) reflect accumulating white matter damage with aging and impair cognition. The role of childhood intelligence is rarely considered in associations between cognitive impairment and WMH. We studied community-dwelling older people all born in 1936, in whom IQ had been assessed at age 11 years. We assessed medical histories, current cognitive ability and quantified WMH on MR imaging. Among 634 participants, mean age 72.7 (SD 0.7), age 11 IQ was the strongest predictor of late life cognitive ability. After accounting for age 11 IQ, greater WMH load was significantly associated with lower late life general cognitive ability (β = -0.14, p < 0.01) and processing speed (β = -0.19, p < 0.001). WMH were also associated independently with lower age 11 IQ (β = -0.08, p < 0.05) and hypertension. In conclusion, having more WMH is significantly associated with lower cognitive ability, after accounting for prior ability, age 11IQ. Early-life IQ also influenced WMH in later life. Determining how lower IQ in youth leads to increasing brain damage with aging is important for future successful cognitive aging. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

A Novel Fixed-Target Task to Determine Articulatory Speed Constraints in Persons with Amyotrophic Lateral Sclerosis

ERIC Educational Resources Information Center

Mefferd, Antje S.; Green, Jordan R.; Pattee, Gary

2012-01-01

Purpose: The goal of this study was to determine if talkers with ALS are limited in their ability to increase lower lip and jaw speed at an early stage of the disease when their speaking rate and intelligibility are only minimally or not affected. Method: A novel metronome paced fixed-target task was used to assess movement speed capacities during…

Relationship between children's intelligence and their emotional/behavioral problems and social competence: gender differences in first graders.

PubMed

Tong, Lian; Shinohara, Ryoji; Sugisawa, Yuka; Tanaka, Emiko; Watanabe, Taeko; Onda, Yoko; Kawashima, Yuri; Yato, Yuko; Yamakawa, Noriko; Koeda, Tatsuya; Ishida, Hiraku; Terakawa, Shinako; Seki, Ayumi; Anme, Tokie

2010-01-01

The present study examines gender differences in the correlations between intelligence and developmental problems as well as social competence in first graders. Ninety parent-child dyads participated in this study. The children comprised 7-year-olds recruited from the first grade of an elementary school. All the children were administered the Wechsler Intelligence Scale for Children-Third Edition (WISC-III), Parent-child Interaction Rating Scale (IRS), and the parent report version of Strength and Difficulties Questionnaire (SDQ). The findings clarified that the processing speed of boys significantly correlated with their peer relationship. On the other hand, the emotional symptoms exhibited by girls had a more common association with their intellectual abilities. The correlations between parenting and intellectual abilities differed in boys and girls. Children's gender should be taken into account when assessing the diversity in their intellectual abilities and developmental problems. Moreover, parenting also influences the development of children in various ways.

Relationship between Children’s Intelligence and Their Emotional/Behavioral Problems and Social Competence: Gender Differences in First Graders

PubMed Central

Tong, Lian; Shinohara, Ryoji; Sugisawa, Yuka; Tanaka, Emiko; Watanabe, Taeko; Onda, Yoko; Kawashima, Yuri; Yato, Yuko; Yamakawa, Noriko; Koeda, Tatsuya; Ishida, Hiraku; Terakawa, Shinako; Seki, Ayumi; Anme, Tokie

2010-01-01

Background The present study examines gender differences in the correlations between intelligence and developmental problems as well as social competence in first graders. Methods Ninety parent-child dyads participated in this study. The children comprised 7-year-olds recruited from the first grade of an elementary school. All the children were administered the Wechsler Intelligence Scale for Children–Third Edition (WISC-III), Parent-child Interaction Rating Scale (IRS), and the parent report version of Strength and Difficulties Questionnaire (SDQ). Results The findings clarified that the processing speed of boys significantly correlated with their peer relationship. On the other hand, the emotional symptoms exhibited by girls had a more common association with their intellectual abilities. The correlations between parenting and intellectual abilities differed in boys and girls. Conclusions Children’s gender should be taken into account when assessing the diversity in their intellectual abilities and developmental problems. Moreover, parenting also influences the development of children in various ways. PMID:20179377

The level and nature of autistic intelligence III: Inspection time.

PubMed

Barbeau, Elise B; Soulières, Isabelle; Dawson, Michelle; Zeffiro, Thomas A; Mottron, Laurent

2013-02-01

Across the autism spectrum, level of intelligence is highly dependent on the psychometric instrument used for assessment, and there are conflicting views concerning which measures best estimate autistic cognitive abilities. Inspection time is a processing speed measure associated with general intelligence in typical individuals. We therefore investigated autism spectrum performance on inspection time in relation to two different general intelligence tests. Autism spectrum individuals were divided into autistic and Asperger subgroups according to speech development history. Compared to a typical control group, mean inspection time for the autistic subgroup but not the Asperger subgroup was significantly shorter (by 31%). However, the shorter mean autistic inspection time was evident only when groups were matched on Wechsler IQ and disappeared when they were matched using Raven's Progressive Matrices. When autism spectrum abilities are compared to typical abilities, results may be influenced by speech development history as well as by the instrument used for intelligence matching. 2013 APA, all rights reserved

Nanoscale View of Dewetting and Coating on Partially Wetted Solids.

PubMed

Deng, Yajun; Chen, Lei; Liu, Qiao; Yu, Jiapeng; Wang, Hao

2016-05-19

There remain significant gaps in our ability to predict dewetting and wetting despite the extensive study over the past century. An important reason is the absence of nanoscopic knowledge about the processes near the moving contact line. This experimental study for the first time obtained the liquid morphology within 10 nm of the contact line, which was receding at low speed (U < 50 nm/s). The results put an end to long-standing debate about the microscopic contact angle, which turned out to be varying with the speed as opposed to the constant-angle assumption that has been frequently employed in modeling. Moreover, a residual film of nanometer thickness ubiquitously remained on the solid after the receding contact line passed. This microscopic residual film modified the solid surface and thus made dewetting far from a simple reverse of wetting. A complete scenario for dewetting and coating is provided.

A noncontact laser technique for circular contouring accuracy measurement

NASA Astrophysics Data System (ADS)

Wang, Charles; Griffin, Bob

2001-02-01

The worldwide competition in manufacturing frequently requires the high-speed machine tools to deliver contouring accuracy in the order of a few micrometers, while moving at relatively high feed rates. Traditional test equipment is rather limited in its capability to measure contours of small radius at high speed. Described here is a new noncontact laser measurement technique for the test of circular contouring accuracy. This technique is based on a single-aperture laser Doppler displacement meter with a flat mirror as the target. It is of a noncontact type with the ability to vary the circular path radius continuously at data rates of up to 1000 Hz. Using this instrument, the actual radius, feed rate, velocity, and acceleration profiles can also be determined. The basic theory of operation, the hardware setup, the data collection, the data processing, and the error budget are discussed.

Implementation of Speed Variation in the Structural Dynamic Assessment of Turbomachinery Flow-Path Components

NASA Technical Reports Server (NTRS)

Brown, Andrew M.; Davis, R. Benjamin; DeHaye, Michael

2013-01-01

During the design of turbomachinery flow path components, the assessment of possible structural resonant conditions is critical. Higher frequency modes of these structures are frequently found to be subject to resonance, and in these cases, design criteria require a forced response analysis of the structure with the assumption that the excitation speed exactly equals the resonant frequency. The design becomes problematic if the response analysis shows a violation of the HCF criteria. One possible solution is to perform "finite-life" analysis, where Miner's rule is used to calculate the actual life in seconds in comparison to the required life. In this situation, it is beneficial to incorporate the fact that, for a variety of turbomachinery control reasons, the speed of the rotor does not actually dwell at a single value but instead dithers about a nominal mean speed and during the time that the excitation frequency is not equal to the resonant frequency, the damage accumulated by the structure is diminished significantly. Building on previous investigations into this process, we show that a steady-state assumption of the response is extremely accurate for this typical case, resulting in the ability to quickly account for speed variation in the finite-life analysis of a component which has previously had its peak dynamic stress at resonance calculated. A technique using Monte Carlo simulation is also presented which can be used when specific speed time histories are not available. The implementation of these techniques can prove critical for successful turbopump design, as the improvement in life when speed variation is considered is shown to be greater than a factor of two

A Mozart is not a Pavarotti: singers outperform instrumentalists on foreign accent imitation

PubMed Central

Christiner, Markus; Reiterer, Susanne Maria

2015-01-01

Recent findings have shown that people with higher musical aptitude were also better in oral language imitation tasks. However, whether singing capacity and instrument playing contribute differently to the imitation of speech has been ignored so far. Research has just recently started to understand that instrumentalists develop quite distinct skills when compared to vocalists. In the same vein the role of the vocal motor system in language acquisition processes has poorly been investigated as most investigations (neurobiological and behavioral) favor to examine speech perception. We set out to test whether the vocal motor system can influence an ability to learn, produce and perceive new languages by contrasting instrumentalists and vocalists. Therefore, we investigated 96 participants, 27 instrumentalists, 33 vocalists and 36 non-musicians/non-singers. They were tested for their abilities to imitate foreign speech: unknown language (Hindi), second language (English) and their musical aptitude. Results revealed that both instrumentalists and vocalists have a higher ability to imitate unintelligible speech and foreign accents than non-musicians/non-singers. Within the musician group, vocalists outperformed instrumentalists significantly. Conclusion: First, adaptive plasticity for speech imitation is not reliant on audition alone but also on vocal-motor induced processes. Second, vocal flexibility of singers goes together with higher speech imitation aptitude. Third, vocal motor training, as of singers, may speed up foreign language acquisition processes. PMID:26379537

A Mozart is not a Pavarotti: singers outperform instrumentalists on foreign accent imitation.

PubMed

Christiner, Markus; Reiterer, Susanne Maria

2015-01-01

Recent findings have shown that people with higher musical aptitude were also better in oral language imitation tasks. However, whether singing capacity and instrument playing contribute differently to the imitation of speech has been ignored so far. Research has just recently started to understand that instrumentalists develop quite distinct skills when compared to vocalists. In the same vein the role of the vocal motor system in language acquisition processes has poorly been investigated as most investigations (neurobiological and behavioral) favor to examine speech perception. We set out to test whether the vocal motor system can influence an ability to learn, produce and perceive new languages by contrasting instrumentalists and vocalists. Therefore, we investigated 96 participants, 27 instrumentalists, 33 vocalists and 36 non-musicians/non-singers. They were tested for their abilities to imitate foreign speech: unknown language (Hindi), second language (English) and their musical aptitude. Results revealed that both instrumentalists and vocalists have a higher ability to imitate unintelligible speech and foreign accents than non-musicians/non-singers. Within the musician group, vocalists outperformed instrumentalists significantly. First, adaptive plasticity for speech imitation is not reliant on audition alone but also on vocal-motor induced processes. Second, vocal flexibility of singers goes together with higher speech imitation aptitude. Third, vocal motor training, as of singers, may speed up foreign language acquisition processes.

3-D Velocimetry of Strombolian Explosions

NASA Astrophysics Data System (ADS)

Taddeucci, J.; Gaudin, D.; Orr, T. R.; Scarlato, P.; Houghton, B. F.; Del Bello, E.

2014-12-01

Using two synchronized high-speed cameras we were able to reconstruct the three-dimensional displacement and velocity field of bomb-sized pyroclasts in Strombolian explosions at Stromboli Volcano. Relatively low-intensity Strombolian-style activity offers a rare opportunity to observe volcanic processes that remain hidden from view during more violent explosive activity. Such processes include the ejection and emplacement of bomb-sized clasts along pure or drag-modified ballistic trajectories, in-flight bomb collision, and gas liberation dynamics. High-speed imaging of Strombolian activity has already opened new windows for the study of the abovementioned processes, but to date has only utilized two-dimensional analysis with limited motion detection and ability to record motion towards or away from the observer. To overcome this limitation, we deployed two synchronized high-speed video cameras at Stromboli. The two cameras, located sixty meters apart, filmed Strombolian explosions at 500 and 1000 frames per second and with different resolutions. Frames from the two cameras were pre-processed and combined into a single video showing frames alternating from one to the other camera. Bomb-sized pyroclasts were then manually identified and tracked in the combined video, together with fixed reference points located as close as possible to the vent. The results from manual tracking were fed to a custom software routine that, knowing the relative position of the vent and cameras, and the field of view of the latter, provided the position of each bomb relative to the reference points. By tracking tens of bombs over five to ten frames at different intervals during one explosion, we were able to reconstruct the three-dimensional evolution of the displacement and velocity fields of bomb-sized pyroclasts during individual Strombolian explosions. Shifting jet directivity and dispersal angle clearly appear from the three-dimensional analysis.

High-speed electro-optic polymers: mm-Wave applications and silica planar lightwave circuit integration

NASA Astrophysics Data System (ADS)

Chang, Daniel H.

The development of high speed polymer electro-optic modulators has seen steady and significant progress in recent years, enabling novel applications in RF-Photonics. Two of these are described in this Thesis: an Opto-Electronic Oscillator (OEO), which is a hybrid RF and optical oscillator capable of high spectral purity, and Photonic Time-Stretch, which is a signal processing technique for waveform spectral shifting with application to photonically-assisted A/D conversion. In both cases, the operating frequencies achieved have been the highest demonstrated to date. Application of this promising material to more complicated devices, however, is stymied by insertion loss performance. Current loss figures, while acceptable for single modulators, are too high for large arrays of modulators or intrinsically long devices such as AWGs or photonic-RF phase shifters. This is especially frustrating in light of a key virtue which polymers possess as a photonic material: its photolithographic process-ability makes patterning complex devices possible. Indeed, the current ascendancy of silica-based waveguide devices can be attributed largely to the same reason. In this Thesis, we also demonstrate the first hybrid device composed of silica planar lightwave circuits (PLCs) and polymer planar waveguides. Our approach utilizes grayscale lithography to enable vertical coupling between polymer and silica layers, minimizing entanglement of their respective fabrication processes. We have achieved coupling excess loss figures on the order of 1dB. We believe this is the natural next step in the development of electro-optic polymer devices. The two technologies are highly complementary. Silica PLCs, with excellent propagation loss and fiber coupling, are ideally suited for long passive waveguiding. By endowing them with the high-speed phase shifting capability offered by polymers, active wideband photonic devices of increasing complexity and array size can be contemplated.

Age-related differences in gap detection: effects of task difficulty and cognitive ability.

PubMed

Harris, Kelly C; Eckert, Mark A; Ahlstrom, Jayne B; Dubno, Judy R

2010-06-01

Differences in gap detection for younger and older adults have been shown to vary with the complexity of the task or stimuli, but the factors that contribute to these differences remain unknown. To address this question, we examined the extent to which age-related differences in processing speed and workload predicted age-related differences in gap detection. Gap detection thresholds were measured for 10 younger and 11 older adults in two conditions that varied in task complexity but used identical stimuli: (1) gap location fixed at the beginning, middle, or end of a noise burst and (2) gap location varied randomly from trial to trial from the beginning, middle, or end of the noise. We hypothesized that gap location uncertainty would place increased demands on cognitive and attentional resources and result in significantly higher gap detection thresholds for older but not younger adults. Overall, gap detection thresholds were lower for the middle location as compared to beginning and end locations and were lower for the fixed than the random condition. In general, larger age-related differences in gap detection were observed for more challenging conditions. That is, gap detection thresholds for older adults were significantly larger for the random condition than for the fixed condition when the gap was at the beginning and end locations but not the middle. In contrast, gap detection thresholds for younger adults were not significantly different for the random and fixed condition at any location. Subjective ratings of workload indicated that older adults found the gap detection task more mentally demanding than younger adults. Consistent with these findings, results of the Purdue Pegboard and Connections tests revealed age-related slowing of processing speed. Moreover, age group differences in workload and processing speed predicted gap detection in younger and older adults when gap location varied from trial to trial; these associations were not observed when gap location remained constant across trials. Taken together, these results suggest that age-related differences in complex measures of auditory temporal processing may be explained, in part, by age-related deficits in processing speed and attention. Copyright 2009 Elsevier B.V. All rights reserved.

Age-related differences in gap detection: Effects of task difficulty and cognitive ability

PubMed Central

Harris, Kelly C.; Eckert, Mark A.; Ahlstrom, Jayne B.; Dubno, Judy R.

2009-01-01

Differences in gap detection for younger and older adults have been shown to vary with the complexity of the task or stimuli, but the factors that contribute to these differences remain unknown. To address this question, we examined the extent to which age-related differences in processing speed and workload predicted age-related differences in gap detection. Gap detection thresholds were measured for 10 younger and 11 older adults in two conditions that varied in task complexity but used identical stimuli: (1) gap location fixed at the beginning, middle, or end of a noise burst and (2) gap location varied randomly from trial to trial from the beginning, middle, or end of the noise. We hypothesized that gap location uncertainty would place increased demands on cognitive and attentional resources and result in significantly higher gap detection thresholds for older but not younger adults. Overall, gap detection thresholds were lower for the middle location as compared to beginning and end locations and were lower for the fixed than the random condition. In general, larger age-related differences in gap detection were observed for more challenging conditions. That is, gap detection thresholds for older adults were significantly larger for the random condition than for the fixed condition when the gap was at the beginning and end locations but not the middle. In contrast, gap detection thresholds for younger adults were not significantly different for the random and fixed condition at any location. Subjective ratings of workload indicated that older adults found the gap-detection task more mentally demanding than younger adults. Consistent with these findings, results of the Purdue Pegboard and Connections tests revealed age-related slowing of processing speed. Moreover, age group differences in workload and processing speed predicted gap detection in younger and older adults when gap location varied from trial to trial; these associations were not observed when gap location remained constant across trials. Taken together, these results suggest that age-related differences in complex measures of auditory temporal processing may be explained, in part, by age-related deficits in processing speed and attention. PMID:19800958

Sleep deprivation influences some but not all processes of supervisory attention

NASA Technical Reports Server (NTRS)

Jennings, J. R.; Monk, T. H.; van der Molen, M. W.

2003-01-01

Does one night of sleep deprivation alter processes of supervisory attention in general or only a specific subset of such processes? Twenty college-aged volunteers, half female, performed a choice reaction time task. A cue indicated that compatible (e.g., right button, right-pointing arrow) or incompatible (e.g., left button, right-pointing arrow) responses were to be given to a stimulus that followed 50 or 500 ms later. The paradigm assessed response inhibition, task-shifting skill, and task strategy-processes inherent in supervisory attention. Performance, along with heart rate, was assessed for 12 hr following normal sleep or a night of complete sleep deprivation. Sleep deprivation altered neither preparation for task shifting nor response inhibition. The ability to use preparatory bias to speed performance did decrease with sleep deprivation. Sleep deprivation appears to selectively affect this supervisory attention process, which is perceived as an active effort to cope with a challenging task.

Sleep deprivation influences some but not all processes of supervisory attention.

PubMed

Jennings, J R; Monk, T H; van der Molen, M W

2003-09-01

Does one night of sleep deprivation alter processes of supervisory attention in general or only a specific subset of such processes? Twenty college-aged volunteers, half female, performed a choice reaction time task. A cue indicated that compatible (e.g., right button, right-pointing arrow) or incompatible (e.g., left button, right-pointing arrow) responses were to be given to a stimulus that followed 50 or 500 ms later. The paradigm assessed response inhibition, task-shifting skill, and task strategy-processes inherent in supervisory attention. Performance, along with heart rate, was assessed for 12 hr following normal sleep or a night of complete sleep deprivation. Sleep deprivation altered neither preparation for task shifting nor response inhibition. The ability to use preparatory bias to speed performance did decrease with sleep deprivation. Sleep deprivation appears to selectively affect this supervisory attention process, which is perceived as an active effort to cope with a challenging task.

Investigating the running abilities of Tyrannosaurus rex using stress-constrained multibody dynamic analysis.

PubMed

Sellers, William I; Pond, Stuart B; Brassey, Charlotte A; Manning, Philip L; Bates, Karl T

2017-01-01

The running ability of Tyrannosaurus rex has been intensively studied due to its relevance to interpretations of feeding behaviour and the biomechanics of scaling in giant predatory dinosaurs. Different studies using differing methodologies have produced a very wide range of top speed estimates and there is therefore a need to develop techniques that can improve these predictions. Here we present a new approach that combines two separate biomechanical techniques (multibody dynamic analysis and skeletal stress analysis) to demonstrate that true running gaits would probably lead to unacceptably high skeletal loads in T. rex . Combining these two approaches reduces the high-level of uncertainty in previous predictions associated with unknown soft tissue parameters in dinosaurs, and demonstrates that the relatively long limb segments of T. rex -long argued to indicate competent running ability-would actually have mechanically limited this species to walking gaits. Being limited to walking speeds contradicts arguments of high-speed pursuit predation for the largest bipedal dinosaurs like T. rex , and demonstrates the power of multiphysics approaches for locomotor reconstructions of extinct animals.

Sex differences in components of imagined perspective transformation.

PubMed

Gardner, Mark R; Sorhus, Ingrid; Edmonds, Caroline J; Potts, Rosalind

2012-05-01

Little research to date has examined whether sex differences in spatial ability extend to the mental self rotation involved in taking on a third party perspective. This question was addressed in the present study by assessing components of imagined perspective transformations in twenty men and twenty women. Participants made speeded left-right judgements about the hand in which an object was held by front- and back- facing schematic human figures in an "own body transformation task." Response times were longer when the figure did not share the same spatial orientation as the participant, and were substantially longer than those made for a control task requiring left-right judgements about the same stimuli from the participant's own point of view. A sex difference in imagined perspective transformation favouring males was found to be restricted to the speed of imagined self rotation, and was not observed for components indexing readiness to take a third party point of view, nor in left-right confusion. These findings indicate that the range of spatial abilities for which a sex difference has been established should be extended to include imagined perspective transformations. They also suggest that imagined perspective transformations may not draw upon those empathic social-emotional perspective taking processes for which females show an advantage. Copyright © 2012 Elsevier B.V. All rights reserved.

Effects of sequential and discrete rapid naming on reading in Japanese children with reading difficulty.

PubMed

Wakamiya, Eiji; Okumura, Tomohito; Nakanishi, Makoto; Takeshita, Takashi; Mizuta, Mekumi; Kurimoto, Naoko; Tamai, Hiroshi

2011-06-01

To clarify whether rapid naming ability itself is a main underpinning factor of rapid automatized naming tests (RAN) and how deep an influence the discrete decoding process has on reading, we performed discrete naming tasks and discrete hiragana reading tasks as well as sequential naming tasks and sequential hiragana reading tasks with 38 Japanese schoolchildren with reading difficulty. There were high correlations between both discrete and sequential hiragana reading and sentence reading, suggesting that some mechanism which automatizes hiragana reading makes sentence reading fluent. In object and color tasks, there were moderate correlations between sentence reading and sequential naming, and between sequential naming and discrete naming. But no correlation was found between reading tasks and discrete naming tasks. The influence of rapid naming ability of objects and colors upon reading seemed relatively small, and multi-item processing may work in relation to these. In contrast, in the digit naming task there was moderate correlation between sentence reading and discrete naming, while no correlation was seen between sequential naming and discrete naming. There was moderate correlation between reading tasks and sequential digit naming tasks. Digit rapid naming ability has more direct effect on reading while its effect on RAN is relatively limited. The ratio of how rapid naming ability influences RAN and reading seems to vary according to kind of the stimuli used. An assumption about components in RAN which influence reading is discussed in the context of both sequential processing and discrete naming speed. Copyright © 2010 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

Psychomotor speed and functional brain MRI 2 years after completing a physical activity treatment.

PubMed

Rosano, Caterina; Venkatraman, Vijay K; Guralnik, Jack; Newman, Anne B; Glynn, Nancy W; Launer, Lenore; Taylor, Christopher A; Williamson, Jeff; Studenski, Stephanie; Pahor, Marco; Aizenstein, Howard

2010-06-01

Short-term adherence to physical activity (PA) in older adults improves psychomotor processing abilities and is associated with greater brain activation. It is not known whether these associations are also significant for longer-term adherence to moderate-intensity activities. We measured the cross-sectional association of regular walking with brain activation while performing the digit symbol substitution test (DSST). Participants of the lifestyle interventions and independence for elders-pilot study were examined 2 years after completing a 1-year treatment, consisting of either PA or education in successful aging (SA). Data were obtained from 20 PA participants who reported having remained active for 2 years after the end of the treatment and from 10 SA participants who reported having remained sedentary during the same period (mean age: 81.5 and 80.8 years). Complete brain activation and behavioral data were available for 17 PA and 10 SA participants. Two years after the formal intervention had ended, the PA group engaged in more minutes of moderate activity and had significantly greater DSST score and higher brain activation within regions important for processing speed (left dorsolateral prefrontal, posterior parietal, and anterior cingulate cortices). Associations were independent of self-reported health, blood pressure, cognition, medication records, gray matter atrophy, and white matter hyperintensities. Persistent engagement in PA may have beneficial effects on psychomotor processing speed and brain activation, even for moderate levels and even when started late in life. Future studies are warranted to assess whether these beneficial effects are explained by delayed neuronal degeneration and/or new neurogenesis.

Numerical Modelling of Foundation Slabs with use of Schur Complement Method

NASA Astrophysics Data System (ADS)

Koktan, Jiří; Brožovský, Jiří

2017-10-01

The paper discusses numerical modelling of foundation slabs with use of advanced numerical approaches, which are suitable for parallel processing. The solution is based on the Finite Element Method with the slab-type elements. The subsoil is modelled with use of Winklertype contact model (as an alternative a multi-parameter model can be used). The proposed modelling approach uses the Schur Complement method to speed-up the computations of the problem. The method is based on a special division of the analyzed model to several substructures. It adds some complexity to the numerical procedures, especially when subsoil models are used inside the finite element method solution. In other hand, this method makes possible a fast solution of large models but it introduces further problems to the process. Thus, the main aim of this paper is to verify that such method can be successfully used for this type of problem. The most suitable finite elements will be discussed, there will be also discussion related to finite element mesh and limitations of its construction for such problem. The core approaches of the implementation of the Schur Complement Method for this type of the problem will be also presented. The proposed approach was implemented in the form of a computer program, which will be also briefly introduced. There will be also presented results of example computations, which prove the speed-up of the solution - there will be shown important speed-up of solution even in the case of on-parallel processing and the ability of bypass size limitations of numerical models with use of the discussed approach.

Neural basis of forward flight control and landing in honeybees.

PubMed

Ibbotson, M R; Hung, Y-S; Meffin, H; Boeddeker, N; Srinivasan, M V

2017-11-06

The impressive repertoire of honeybee visually guided behaviors, and their ability to learn has made them an important tool for elucidating the visual basis of behavior. Like other insects, bees perform optomotor course correction to optic flow, a response that is dependent on the spatial structure of the visual environment. However, bees can also distinguish the speed of image motion during forward flight and landing, as well as estimate flight distances (odometry), irrespective of the visual scene. The neural pathways underlying these abilities are unknown. Here we report on a cluster of descending neurons (DNIIIs) that are shown to have the directional tuning properties necessary for detecting image motion during forward flight and landing on vertical surfaces. They have stable firing rates during prolonged periods of stimulation and respond to a wide range of image speeds, making them suitable to detect image flow during flight behaviors. While their responses are not strictly speed tuned, the shape and amplitudes of their speed tuning functions are resistant to large changes in spatial frequency. These cells are prime candidates not only for the control of flight speed and landing, but also the basis of a neural 'front end' of the honeybee's visual odometer.

Symptoms versus neurocognition as predictors of change in life skills in schizophrenia after outpatient rehabilitation.

PubMed

Kurtz, Matthew M; Wexler, Bruce E; Fujimoto, Marco; Shagan, Dana S; Seltzer, James C

2008-07-01

A growing body of literature has shown that neurocognitive deficits in schizophrenia account for 20-60% of the variance in measures of outcome, and in many studies are more closely related to outcome than symptoms [Green, M.F., Kern, R.S., Braff, D.L., Mintz, J., 2000. Neurocognitive deficits and functional outcome in schizophrenia: are we measuring the "right stuff"? Schizophr. Bull. 26(1), 119-136; Green, M.F., Kern, R.S., Heaton, R.K., 2004. Longitudinal studies of cognition and functional outcome in schizophrenia: implications for MATRICS. Schizophr. Res. 72(1), 41-51]. Most of these studies have been cross-sectional, few longitudinal studies have investigated the degree to which neurocognition and symptoms predict ability to benefit from outpatient rehabilitation, and no longitudinal studies use measures of everyday life skills that are performance-based. In the current study we investigated the relationship between five measures of neurocognitive function, crystallized verbal ability, visual sustained vigilance, verbal learning, problem-solving, and processing speed, and two measures of symptoms, total positive and negative symptoms, and change on a performance-based measure of everyday life skills after a year of outpatient rehabilitation. Rehabilitation consisted of both psychosocial and cognitive interventions. Forty-six patients with schizophrenia or schizoaffective disorder were studied. Results of a linear regression model revealed that verbal learning predicted a significant amount of the variance in change in performance-based measures of everyday life skills after outpatient rehabilitation, even when variance for all other variables in the model was accounted for. Measures of crystallized verbal ability, sustained visual vigilance, problem-solving, processing speed and symptoms were not linked to functional status change. These findings emphasize the importance of verbal learning for benefiting from psychosocial and cognitive rehabilitation interventions, and suggest the development of alternative rehabilitation strategies for those who do not benefit.

Children's Writing Ability: Effects of Parent's Education, Mental Speed and Intelligence

ERIC Educational Resources Information Center

Rindermann, Heiner; Michou, Christina Dimitra; Thompson, James

2011-01-01

Verbal ability comprises receptive (understanding) and active (producing) facets. While the first (e.g. as literacy in PIRLS and PISA) is frequently analyzed in its relationship to further cognitive abilities and parental attributes the latter is rarely investigated. The present study using data from N=280 students aged 9 to 14 years investigated…

Non-"g" Residuals of the SAT and ACT Predict Specific Abilities

ERIC Educational Resources Information Center

Coyle, Thomas R.; Purcell, Jason M.; Snyder, Anissa C.; Kochunov, Peter

2013-01-01

This research examined whether non-"g" residuals of the SAT and ACT subtests, obtained after removing g, predicted specific abilities. Non-"g" residuals of the verbal and math subtests of the SAT and ACT were correlated with academic (verbal and math) and non-academic abilities (speed and shop), both based on the Armed Services…

A New Parallel Approach for Accelerating the GPU-Based Execution of Edge Detection Algorithms

PubMed Central

Emrani, Zahra; Bateni, Soroosh; Rabbani, Hossein

2017-01-01

Real-time image processing is used in a wide variety of applications like those in medical care and industrial processes. This technique in medical care has the ability to display important patient information graphi graphically, which can supplement and help the treatment process. Medical decisions made based on real-time images are more accurate and reliable. According to the recent researches, graphic processing unit (GPU) programming is a useful method for improving the speed and quality of medical image processing and is one of the ways of real-time image processing. Edge detection is an early stage in most of the image processing methods for the extraction of features and object segments from a raw image. The Canny method, Sobel and Prewitt filters, and the Roberts’ Cross technique are some examples of edge detection algorithms that are widely used in image processing and machine vision. In this work, these algorithms are implemented using the Compute Unified Device Architecture (CUDA), Open Source Computer Vision (OpenCV), and Matrix Laboratory (MATLAB) platforms. An existing parallel method for Canny approach has been modified further to run in a fully parallel manner. This has been achieved by replacing the breadth- first search procedure with a parallel method. These algorithms have been compared by testing them on a database of optical coherence tomography images. The comparison of results shows that the proposed implementation of the Canny method on GPU using the CUDA platform improves the speed of execution by 2–100× compared to the central processing unit-based implementation using the OpenCV and MATLAB platforms. PMID:28487831

A New Parallel Approach for Accelerating the GPU-Based Execution of Edge Detection Algorithms.

PubMed

Emrani, Zahra; Bateni, Soroosh; Rabbani, Hossein

2017-01-01

Real-time image processing is used in a wide variety of applications like those in medical care and industrial processes. This technique in medical care has the ability to display important patient information graphi graphically, which can supplement and help the treatment process. Medical decisions made based on real-time images are more accurate and reliable. According to the recent researches, graphic processing unit (GPU) programming is a useful method for improving the speed and quality of medical image processing and is one of the ways of real-time image processing. Edge detection is an early stage in most of the image processing methods for the extraction of features and object segments from a raw image. The Canny method, Sobel and Prewitt filters, and the Roberts' Cross technique are some examples of edge detection algorithms that are widely used in image processing and machine vision. In this work, these algorithms are implemented using the Compute Unified Device Architecture (CUDA), Open Source Computer Vision (OpenCV), and Matrix Laboratory (MATLAB) platforms. An existing parallel method for Canny approach has been modified further to run in a fully parallel manner. This has been achieved by replacing the breadth- first search procedure with a parallel method. These algorithms have been compared by testing them on a database of optical coherence tomography images. The comparison of results shows that the proposed implementation of the Canny method on GPU using the CUDA platform improves the speed of execution by 2-100× compared to the central processing unit-based implementation using the OpenCV and MATLAB platforms.

Working Memory Influences Processing Speed and Reading Fluency in ADHD

PubMed Central

Jacobson, Lisa A.; Ryan, Matthew; Martin, Rebecca B.; Ewen, Joshua; Mostofsky, Stewart H.; Denckla, Martha B.; Mahone, E. Mark

2012-01-01

Processing speed deficits affect reading efficiency, even among individuals who recognize and decode words accurately. Children with ADHD who decode words accurately can still have inefficient reading fluency, leading to a bottleneck in other cognitive processes. This “slowing” in ADHD is associated with deficits in fundamental components of executive function underlying processing speed, including response selection. The purpose of the present study was to deconstruct processing speed in order to determine which components of executive control best explain the “processing” speed deficits related to reading fluency in ADHD. Participants (41 ADHD, 21 controls), ages 9-14, screened for language disorders, word reading deficits, and psychiatric disorders, were administered measures of copying speed, processing speed, reading fluency, working memory, reaction time, inhibition, and auditory attention span. Compared to controls, children with ADHD showed reduced oral and silent reading fluency, and reduced processing speed—driven primarily by deficits on WISC-IV Coding. In contrast, groups did not differ on copying speed. After controlling for copying speed, sex, severity of ADHD-related symptomatology, and GAI, slowed “processing” speed (i.e., Coding) was significantly associated with verbal span and measures of working memory, but not with measures of response control/inhibition, lexical retrieval speed, reaction time, or intra-subject variability. Further, “processing” speed (i.e., Coding, residualized for copying speed) and working memory were significant predictors of oral reading fluency. Abnormalities in working memory and response selection (which are frontally-mediated and enter into the output side of processing speed) may play an important role in deficits in reading fluency in ADHD, potentially more than posteriorally-mediated problems with orienting of attention or perceiving the stimulus. PMID:21287422

The comparison of the visuo-spatial abilities of dyslexic and normal students in Taiwan and Hong Kong.

PubMed

Wang, Li-Chih; Yang, Hsien-Ming

2011-01-01

This study focused on a comparison of the visuo-spatial abilities (correct rate and speed) between dyslexic and normal students in Taiwan and Hong Kong. There were a total of 120 10-12 year old students. Thirty students had been diagnosed as dyslexic in Taiwan (T.W. dyslexia) and thirty students had been diagnosed as dyslexic in Hong Kong (H.K. dyslexia). Overall, 30 of the Taiwanese participants (T.W. normal) and 30 of the Hong Kong participants (H.K. normal) had received no special education. Dyslexic individuals were diagnosed by the doctors' clinical determination. The material was designed using Autodesk 3ds Max. The participants rotated 3D figures by themselves to find a ball. The results indicated that there was very little difference between dyslexic and normal students. However, the most significant difference between dyslexic and normal student was answering speed, especially in the combined data and the male data. An one-way ANOVA test indicated that in terms of rate and answering speed there was no difference between the H.K. and the T.W. dyslexics. Similar results were also found for the students with normal reading abilities in T.W. and H.K. The criterions for defining the visuo-spatial abilities of dyslexia students appear to be similar in Taiwan and Hong Kong. In addition, there is no difference between students' visuo-spatial abilities even though Chinese literacy instructions differed in the two areas. Copyright © 2011 Elsevier Ltd. All rights reserved.

Fast Sealift and Maritime Prepositioning Options for Improving Sealift Capabilities

DTIC Science & Technology

1991-01-01

cargo ships with speeds of 22 to 25 knots as fas* The eight existing T- AKRs , which have a speed of 30... cargo than in the case of no ship attrition. 2.0 ---- Without -- attrition --- • attrition 0- 1.0- High -capacity Low-cost Improved MPS( A ) SES T- AKR ...fast sealift and maritime prepositioning ships and evaluates their performance in terms of speed and the ability to make cumulative cargo deliveries

Genetic effects on information processing speed are moderated by age--converging results from three samples.

PubMed

Ising, M; Mather, K A; Zimmermann, P; Brückl, T; Höhne, N; Heck, A; Schenk, L A; Rujescu, D; Armstrong, N J; Sachdev, P S; Reppermund, S

2014-06-01

Information processing is a cognitive trait forming the basis of complex abilities like executive function. The Trail Making Test (TMT) is a well-established test of information processing with moderate to high heritability. Age of the individual also plays an important role. A number of genetic association studies with the TMT have been performed, which, however, did not consider age as a moderating factor. We report the results of genome-wide association studies (GWASs) on age-independent and age-dependent TMT performance in two population-representative community samples (Munich Antidepressant Response Signature, MARS: N1 = 540; Ludwig Maximilians University, LMU: N2 = 350). Age-dependent genome-wide findings were then evaluated in a third sample of healthy elderly subjects (Sydney Memory and Ageing Study, Sydney MAS: N3 = 448). While a meta-analysis on the GWAS findings did not reveal age-independent TMT associations withstanding correction for multiple testing, we found a genome-wide significant age-moderated effect between variants in the DSG1 gene region and TMT-A performance predominantly reflecting visual processing speed (rs2199301, P(meta-analysis) = 1.3 × 10(-7)). The direction of the interaction suggests for the minor allele a beneficial effect in younger adults turning into a detrimental effect in older adults. The detrimental effect of the missense single nucleotide polymorphism rs1426310 within the same DSG1 gene region could be replicated in Sydney MAS participants aged 70-79, but not in those aged 80 years and older, presumably a result of survivor bias. Our findings demonstrate opposing effects of DSG1 variants on information processing speed depending on age, which might be related to the complex processes that DSG1 is involved with, including cell adhesion and apoptosis. © 2014 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

Conditional Dependence between Response Time and Accuracy: An Overview of its Possible Sources and Directions for Distinguishing between Them

PubMed Central

Bolsinova, Maria; Tijmstra, Jesper; Molenaar, Dylan; De Boeck, Paul

2017-01-01

With the widespread use of computerized tests in educational measurement and cognitive psychology, registration of response times has become feasible in many applications. Considering these response times helps provide a more complete picture of the performance and characteristics of persons beyond what is available based on response accuracy alone. Statistical models such as the hierarchical model (van der Linden, 2007) have been proposed that jointly model response time and accuracy. However, these models make restrictive assumptions about the response processes (RPs) that may not be realistic in practice, such as the assumption that the association between response time and accuracy is fully explained by taking speed and ability into account (conditional independence). Assuming conditional independence forces one to ignore that many relevant individual differences may play a role in the RPs beyond overall speed and ability. In this paper, we critically consider the assumption of conditional independence and the important ways in which it may be violated in practice from a substantive perspective. We consider both conditional dependences that may arise when all persons attempt to solve the items in similar ways (homogeneous RPs) and those that may be due to persons differing in fundamental ways in how they deal with the items (heterogeneous processes). The paper provides an overview of what we can learn from observed conditional dependences. We argue that explaining and modeling these differences in the RPs is crucial to increase both the validity of measurement and our understanding of the relevant RPs. PMID:28261136

A Portable Platform for Evaluation of Visual Performance in Glaucoma Patients

PubMed Central

Rosen, Peter N.; Boer, Erwin R.; Gracitelli, Carolina P. B.; Abe, Ricardo Y.; Diniz-Filho, Alberto; Marvasti, Amir H.; Medeiros, Felipe A.

2015-01-01

Purpose To propose a new tablet-enabled test for evaluation of visual performance in glaucoma, the PERformance CEntered Portable Test (PERCEPT), and to evaluate its ability to predict history of falls and motor vehicle crashes. Design Cross-sectional study. Methods The study involved 71 patients with glaucomatous visual field defects on standard automated perimetry (SAP) and 59 control subjects. The PERCEPT was based on the concept of increasing visual task difficulty to improve detection of central visual field losses in glaucoma patients. Subjects had to perform a foveal 8-alternative-forced-choice orientation discrimination task, while detecting a simultaneously presented peripheral stimulus within a limited presentation time. Subjects also underwent testing with the Useful Field of View (UFOV) divided attention test. The ability to predict history of motor vehicle crashes and falls was investigated by odds ratios and incident-rate ratios, respectively. Results When adjusted for age, only the PERCEPT processing speed parameter showed significantly larger values in glaucoma compared to controls (difference: 243ms; P<0.001). PERCEPT results had a stronger association with history of motor vehicle crashes and falls than UFOV. Each 1 standard deviation increase in PERCEPT processing speed was associated with an odds ratio of 2.69 (P = 0.003) for predicting history of motor vehicle crashes and with an incident-rate ratio of 1.95 (P = 0.003) for predicting history of falls. Conclusion A portable platform for testing visual function was able to detect functional deficits in glaucoma, and its results were significantly associated with history of involvement in motor vehicle crashes and history of falls. PMID:26445501

Sensory and Cognitive Determinants of Reading Speed

ERIC Educational Resources Information Center

Jackson, Mark D.; McClelland, James L.

1975-01-01

Fast and average readers were tested on four tasks. Fast readers appear to pick up more information per fixation on structured textual material, and had a greater span of apprehension for unrelated elements. Results disagree with the view that reading speed depends solely on ability to infer missing information. (CHK)

Flexible digital signal processing architecture for narrowband and spread-spectrum lock-in detection in multiphoton microscopy and time-resolved spectroscopy

PubMed Central

Wilson, Jesse W.; Park, Jong Kang; Warren, Warren S.

2015-01-01

The lock-in amplifier is a critical component in many different types of experiments, because of its ability to reduce spurious or environmental noise components by restricting detection to a single frequency and phase. One example application is pump-probe microscopy, a multiphoton technique that leverages excited-state dynamics for imaging contrast. With this application in mind, we present here the design and implementation of a high-speed lock-in amplifier on the field-programmable gate array (FPGA) coprocessor of a data acquisition board. The most important advantage is the inherent ability to filter signals based on more complex modulation patterns. As an example, we use the flexibility of the FPGA approach to enable a novel pump-probe detection scheme based on spread-spectrum communications techniques. PMID:25832238

Flexible digital signal processing architecture for narrowband and spread-spectrum lock-in detection in multiphoton microscopy and time-resolved spectroscopy.

PubMed

Wilson, Jesse W; Park, Jong Kang; Warren, Warren S; Fischer, Martin C

2015-03-01

The lock-in amplifier is a critical component in many different types of experiments, because of its ability to reduce spurious or environmental noise components by restricting detection to a single frequency and phase. One example application is pump-probe microscopy, a multiphoton technique that leverages excited-state dynamics for imaging contrast. With this application in mind, we present here the design and implementation of a high-speed lock-in amplifier on the field-programmable gate array (FPGA) coprocessor of a data acquisition board. The most important advantage is the inherent ability to filter signals based on more complex modulation patterns. As an example, we use the flexibility of the FPGA approach to enable a novel pump-probe detection scheme based on spread-spectrum communications techniques.

Speed Isn't Everything: Complex Processing Speed Measures Mask Individual Differences and Developmental Changes in Executive Control

ERIC Educational Resources Information Center

Cepeda, Nicholas J.; Blackwell, Katharine A.; Munakata, Yuko

2013-01-01

The rate at which people process information appears to influence many aspects of cognition across the lifespan. However, many commonly accepted measures of "processing speed" may require goal maintenance, manipulation of information in working memory, and decision-making, blurring the distinction between processing speed and executive…

Working memory span and motor and cognitive speed in schizophrenia.

PubMed

Brébion, Gildas; David, Anthony S; Jones, Hugh M; Pilowsky, Lyn S

2009-06-01

The aim of this study was to investigate the verbal working memory deficit and decrease of motor and cognitive speed in patients with schizophrenia, and to clarify their associations with negative and depressive symptomatology. Forty patients with schizophrenia and 41 healthy control individuals were administered the backward digit span to assess the working memory capacity, along with 3 tests of processing speed. Patients demonstrated reduced backward digit span, as well as decreased motor and cognitive speed. Regression analyses indicated that the backward digit span was associated with cognitive speed. It was not associated with either negative or depressive symptoms. Decreased processing speed was unrelated to negative symptoms, but the depression score was significantly associated with the cognitive speed measure. Working memory and processing speed seem to share a cognitive component. Depression, but not negative symptoms, affects processing speed, especially by decreasing cognitive speed.

Importance of CME Radial Expansion on the Ability of Slow CMEs to Drive Shocks

NASA Astrophysics Data System (ADS)

Lugaz, N.; Farrugia, C. J.; Winslow, R. M.; Small, C. R.; Manion, T.; Savani, N.

2017-12-01

Coronal mass ejections (CMEs) may disturb the solar wind either by overtaking it, or by expanding into it, or both. CMEs whose front moves faster in the solar wind frame than the fast magnetosonic speed, drive shocks. In general, near 1 AU, CMEs with speed greater than about 500 km s-1 drive shocks, whereas slower CMEs do not. However, CMEs as slow as 350 km s-1 may sometimes, although rarely, drive shocks. Here, we study these slow CMEs with shocks and investigate the importance of CME expansion in contributing to their ability to drive shocks and in enhancing shock strength. Our focus is on CMEs with average speeds under 375 km s-1. From Wind measurements from 1996 to 2016, we find 22 cases of such shock-driving slow CMEs, and, for about half of them, the existence of the shock appears to be strongly related to CME expansion. We also investigate the proportion of all CMEs with speeds under 500 km s-1 with and without shocks in solar cycles 23 and 24, depending on their speed. We find no systematic difference, as might have been expected on the basis of the lower solar wind and Alfven speeds reported for solar cycle 24 vs. 23. The slower expansion speed of CMEs in solar cycle 24 is a reasonable explanation for this lack of increased frequency of shocks, but further studies are required.

Infant discrimination of rapid auditory cues predicts later language impairment.

PubMed

Benasich, April A; Tallal, Paula

2002-10-17

The etiology and mechanisms of specific language impairment (SLI) in children are unknown. Differences in basic auditory processing abilities have been suggested to underlie their language deficits. Studies suggest that the neuropathology, such as atypical patterns of cerebral lateralization and cortical cellular anomalies, implicated in such impairments likely occur early in life. Such anomalies may play a part in the rapid processing deficits seen in this disorder. However, prospective, longitudinal studies in infant populations that are critical to examining these hypotheses have not been done. In the study described, performance on brief, rapidly-presented, successive auditory processing and perceptual-cognitive tasks were assessed in two groups of infants: normal control infants with no family history of language disorders and infants from families with a positive family history for language impairment. Initial assessments were obtained when infants were 6-9 months of age (M=7.5 months) and the sample was then followed through age 36 months. At the first visit, infants' processing of rapid auditory cues as well as global processing speed and memory were assessed. Significant differences in mean thresholds were seen in infants born into families with a history of SLI as compared with controls. Examination of relations between infant processing abilities and emerging language through 24 months-of-age revealed that threshold for rapid auditory processing at 7.5 months was the single best predictor of language outcome. At age 3, rapid auditory processing threshold and being male, together predicted 39-41% of the variance in language outcome. Thus, early deficits in rapid auditory processing abilities both precede and predict subsequent language delays. These findings support an essential role for basic nonlinguistic, central auditory processes, particularly rapid spectrotemporal processing, in early language development. Further, these findings provide a temporal diagnostic window during which future language impairments may be addressed.

Influences of thermal acclimation and acute temperature change on the motility of epithelial wound-healing cells (keratocytes) of tropical, temperate and Antarctic fish.

PubMed

Ream, Rachael A; Theriot, Julie A; Somero, George N

2003-12-01

The ability to heal superficial wounds is an important element in an organism's repertoire of adaptive responses to environmental stress. In fish, motile cells termed keratocytes are thought to play important roles in the wound-healing process. Keratocyte motility, like other physiological rate processes, is likely to be dependent on temperature and to show adaptive variation among differently thermally adapted species. We have quantified the effects of acute temperature change and thermal acclimation on actin-based keratocyte movement in primary cultures of keratocytes from four species of teleost fish adapted to widely different thermal conditions: two eurythermal species, the longjaw mudsucker Gillichthys mirabilis (environmental temperature range of approximately 10-37 degrees C) and a desert pupfish, Cyprinodon salinus (10-40 degrees C), and two species from stable thermal environments, an Antarctic notothenioid, Trematomus bernacchii (-1.86 degrees C), and a tropical clownfish, Amphiprion percula (26-30 degrees C). For all species, keratocyte speed increased with increasing temperature. G. mirabilis and C. salinus keratocytes reached maximal speeds at 25 degrees C and 35 degrees C, respectively, temperatures within the species' normal thermal ranges. Keratocytes of the stenothermal species continued to increase in speed as temperature increased above the species' normal temperature ranges. The thermal limits of keratocyte motility appear to exceed those of whole-organism thermal tolerance, notably in the case of T. bernacchii. Keratocytes of T. bernacchii survived supercooling to -6 degrees C and retained motility at temperatures as high as 20 degrees C. Mean keratocyte speed was conserved at physiological temperatures for the three temperate and tropical species, which suggests that a certain rate of motility is advantageous for wound healing. However, there was no temperature compensation in speed of movement for keratocytes of the Antarctic fish, which have extremely slow rates of movement at physiological temperatures. Keratocytes from all species moved in a persistent, unidirectional manner at low temperatures but at higher temperatures began to take more circular or less-persistent paths. Thermal acclimation affected the persistence and turning magnitude of keratocytes, with warmer acclimations generally yielding more persistent cells that followed straighter paths. However, acclimation did not alter the effect of experimental temperature on cellular speed. These findings suggest that more than one temperature-sensitive mechanism may govern cell motility: the rate-limiting process(es) responsible for speed is distinct from the mechanism(s) underlying directionality and persistence. Keratocytes represent a useful study system for evaluating the effects of temperature at the cellular level and for studying adaptive variation in actin-based cellular movement and capacity for wound healing.

Attentional Disengagement in Adults with Williams syndrome

PubMed Central

Lense, Miriam D.; Key, Alexandra P.; Dykens, Elisabeth M.

2011-01-01

Williams syndrome (WS) is a neurodevelopmental disorder characterized by a distinctive behavioral and cognitive profile, including widespread problems with attention. However, the specific nature of their attentional difficulties, such as inappropriate attentional allocation and/or poor attentional disengagement abilities, has yet to be elucidated. Furthermore, it is unknown if there is an underlying difficulty with the temporal dynamics of attention in WS or if their attentional difficulties are task-dependent, because previous studies have examined attention in established areas of deficit and atypicality (specifically, visuospatial and face processing). In this study, we examined attentional processing in 14 adults with WS (20-59 years) and 17 typically developing controls (19-39 years) using an attentional blink (AB) paradigm. The AB is the decreased ability to detect a second target when it is presented in close proximity to an initial target. Overall, adults with WS had an AB that was prolonged in duration, but no different in magnitude, compared with typically developing control participants. AB performance was not explained by IQ, working memory, or processing speed in either group. Thus, results suggest that the attention problems in WS are primarily due to general attentional disengagement difficulties rather than inappropriate attentional allocation. PMID:21885176

Attentional limitations with Head-Up Displays

NASA Technical Reports Server (NTRS)

Mccann, Robert S.; Foyle, David C.; Johnston, James C.

1993-01-01

Recent models of visual information processing suggest that visual attention can be focussed on either Head-Up Displays (HUD) or on the world beyond them, but not on both simultaneously. This hypothesis was tested in a part-task simulation in which subjects viewed a simulated approach to a runway with a HUD superimposed. An alphanumeric cue ('IFR' or 'VFR') appeared on either the HUD or the runway and was followed by two sets of three geometric forms; one set on the HUD and one set on the runway. Each set contained one potential target, either a stop sign or a diamond. If the cue spelled 'IFR', subjects made a speeded response based on the identity of the HUD target; if the cue spelled 'VFR', subjects made a speeded response based on the identity of the runway target. Regardless of cue location (HUD or Runway), responses were faster when the cue and the relevant target were part of the same perceptual group (i.e., both on the HUD or both on the runway) than when they were part of different perceptual groups. These results, as well as others, suggest that attentional constraints place severe limits on the ability of pilots to process HUD-referenced information and world-referenced information simultaneously. In addition, they provide direct evidence that transitioning from processing HUD information to processing world information requires an attention shift. Implications for HUD design are considered.

Mesoscopic structural phase progression in photo-excited VO 2 revealed by time-resolved x-ray diffraction microscopy

DOE PAGES

Zhu, Yi; Cai, Zhonghou; Chen, Pice; ...

2016-02-26

Dynamical phase separation during a solid-solid phase transition poses a challenge for understanding the fundamental processes in correlated materials. Critical information underlying a phase transition, such as localized phase competition, is difficult to reveal by measurements that are spatially averaged over many phase seperated regions. The ability to simultanousely track the spatial and temporal evolution of such systems is essential to understanding mesoscopic processes during a phase transition. Using state-of- the-art time-resolved hard x-ray diffraction microscopy, we directly visualize the structural phase progression in a VO 2 film upon photoexcitation. Following a homogenous in-plane optical excitation, the phase transformation ismore » initiated at discrete sites and completed by the growth of one lattice structure into the other, instead of a simultaneous isotropic lattice symmetry change. The time-dependent x-ray diffraction spatial maps show that the in-plane phase progression in laser-superheated VO 2 is via a displacive lattice transformation as a result of relaxation from an excited monoclinic phase into a rutile phase. The speed of the phase front progression is quantitatively measured, which is faster than the process driven by in-plane thermal diffusion but slower than the sound speed in VO 2. Lastly, the direct visualization of localized structural changes in the time domain opens a new avenue to study mesoscopic processes in driven systems.« less

Mesoscopic structural phase progression in photo-excited VO2 revealed by time-resolved x-ray diffraction microscopy

NASA Astrophysics Data System (ADS)

Zhu, Yi; Cai, Zhonghou; Chen, Pice; Zhang, Qingteng; Highland, Matthew J.; Jung, Il Woong; Walko, Donald A.; Dufresne, Eric M.; Jeong, Jaewoo; Samant, Mahesh G.; Parkin, Stuart S. P.; Freeland, John W.; Evans, Paul G.; Wen, Haidan

2016-02-01

Dynamical phase separation during a solid-solid phase transition poses a challenge for understanding the fundamental processes in correlated materials. Critical information underlying a phase transition, such as localized phase competition, is difficult to reveal by measurements that are spatially averaged over many phase separated regions. The ability to simultaneously track the spatial and temporal evolution of such systems is essential to understanding mesoscopic processes during a phase transition. Using state-of-the-art time-resolved hard x-ray diffraction microscopy, we directly visualize the structural phase progression in a VO2 film upon photoexcitation. Following a homogenous in-plane optical excitation, the phase transformation is initiated at discrete sites and completed by the growth of one lattice structure into the other, instead of a simultaneous isotropic lattice symmetry change. The time-dependent x-ray diffraction spatial maps show that the in-plane phase progression in laser-superheated VO2 is via a displacive lattice transformation as a result of relaxation from an excited monoclinic phase into a rutile phase. The speed of the phase front progression is quantitatively measured, and is faster than the process driven by in-plane thermal diffusion but slower than the sound speed in VO2. The direct visualization of localized structural changes in the time domain opens a new avenue to study mesoscopic processes in driven systems.

Mesoscopic structural phase progression in photo-excited VO2 revealed by time-resolved x-ray diffraction microscopy.

PubMed

Zhu, Yi; Cai, Zhonghou; Chen, Pice; Zhang, Qingteng; Highland, Matthew J; Jung, Il Woong; Walko, Donald A; Dufresne, Eric M; Jeong, Jaewoo; Samant, Mahesh G; Parkin, Stuart S P; Freeland, John W; Evans, Paul G; Wen, Haidan

2016-02-26

Dynamical phase separation during a solid-solid phase transition poses a challenge for understanding the fundamental processes in correlated materials. Critical information underlying a phase transition, such as localized phase competition, is difficult to reveal by measurements that are spatially averaged over many phase separated regions. The ability to simultaneously track the spatial and temporal evolution of such systems is essential to understanding mesoscopic processes during a phase transition. Using state-of-the-art time-resolved hard x-ray diffraction microscopy, we directly visualize the structural phase progression in a VO2 film upon photoexcitation. Following a homogenous in-plane optical excitation, the phase transformation is initiated at discrete sites and completed by the growth of one lattice structure into the other, instead of a simultaneous isotropic lattice symmetry change. The time-dependent x-ray diffraction spatial maps show that the in-plane phase progression in laser-superheated VO2 is via a displacive lattice transformation as a result of relaxation from an excited monoclinic phase into a rutile phase. The speed of the phase front progression is quantitatively measured, and is faster than the process driven by in-plane thermal diffusion but slower than the sound speed in VO2. The direct visualization of localized structural changes in the time domain opens a new avenue to study mesoscopic processes in driven systems.

Gender Differences in Processing Speed: A Review of Recent Research

ERIC Educational Resources Information Center

Roivainen, Eka

2011-01-01

A review of recent large-scale studies on gender differences in processing speed and on the cognitive factors assumed to affect processing speed was performed. It was found that females have an advantage in processing speed tasks involving digits and alphabets as well as in rapid naming tasks while males are faster on reaction time tests and…

Phenotypic and genetic associations between reading and attention-deficit/hyperactivity disorder dimensions in adolescence.

PubMed

Plourde, Vickie; Boivin, Michel; Brendgen, Mara; Vitaro, Frank; Dionne, Ginette

2017-10-01

Multiple studies have shown that reading abilities and attention-deficit/hyperactivity disorder symptoms, mainly inattention symptoms, are phenotypically and genetically associated during childhood. However, few studies have looked at these associations during adolescence to investigate possible developmental changes. The aim of the study is to examine the genetic and environmental etiology of the associations between inattention and hyperactivity reported by parents, and reading accuracy, reading speed, and word reading in a population-based twin sample (Quebec Newborn Twin Study). Participants were between 14 and 15 years of age at the time of testing (N = 668-837). Phenotypic results showed that when nonverbal and verbal abilities were controlled, inattention, but not hyperactivity/impulsivity, was a modest and significant predictor of reading accuracy, reading speed, and word reading. The associations between inattention and all reading abilities were partly explained by genetic and unique environmental factors. However, the genetic correlations were no longer significant after controlling for verbal abilities. In midadolescence, inattention is the attention-deficit/hyperactivity disorder dimension associated with reading abilities, but they could also share genetic factors with general verbal skills.

Identification of stair climbing ability levels in community-dwelling older adults based on the geometric mean of stair ascent and descent speed: The GeMSS classifier.

PubMed

Mayagoitia, Ruth E; Harding, John; Kitchen, Sheila

2017-01-01

The aim was to develop a quantitative approach to identify three stair-climbing ability levels of older adults: no, somewhat and considerable difficulty. Timed-up-and-go test, six-minute-walk test, and Berg balance scale were used for statistical comparison to a new stair climbing ability classifier based on the geometric mean of stair speeds (GeMSS) in ascent and descent on a flight of eight stairs with a 28° pitch in the housing unit where the participants, 28 (16 women) urban older adults (62-94 years), lived. Ordinal logistic regression revealed the thresholds between the three ability levels for each functional test were more stringent than thresholds found in the literature to classify walking ability levels. Though a small study, the intermediate classifier shows promise of early identification of difficulties with stairs, in order to make timely preventative interventions. Further studies are necessary to obtain scaling factors for stairs with other pitches. Copyright © 2016 Elsevier Ltd. All rights reserved.

Is age kinder to the initially more able?: Yes, and no

PubMed Central

Gow, Alan J.; Johnson, Wendy; Mishra, Gita; Richards, Marcus; Kuh, Diana; Deary, Ian J.

2012-01-01

Although a number of analyses have addressed whether initial cognitive ability level is associated with age-related cognitive decline, results have been inconsistent. Latent growth curve modeling was applied to two aging cohorts, extending previous analyses with a further wave of data collection, or as a more appropriate analytical methodology than used previously. In the Lothian Birth Cohort 1921, cognitive ability at age 11 was not associated with cognitive change from age 79 to 87, either in general cognitive ability, or in tests of reasoning, memory and executive function. However, data from the MRC National Survey of Health and Development suggested that higher cognitive ability at age 15 predicted less decline between ages 43 and 53 years in a latent cognitive factor from tests of verbal memory and search speed, and in search speed when considered separately. The results are discussed in terms of the differences between the cohorts and the interpretability of the analytical approach. Suggestions are made about when initial ability might be cognitively protective, and study requirements to bring about a clearer resolution. PMID:23690652

How Accumulated Real Life Stress Experience and Cognitive Speed Interact on Decision-Making Processes

PubMed Central

Friedel, Eva; Sebold, Miriam; Kuitunen-Paul, Sören; Nebe, Stephan; Veer, Ilya M.; Zimmermann, Ulrich S.; Schlagenhauf, Florian; Smolka, Michael N.; Rapp, Michael; Walter, Henrik; Heinz, Andreas

2017-01-01

Rationale: Advances in neurocomputational modeling suggest that valuation systems for goal-directed (deliberative) on one side, and habitual (automatic) decision-making on the other side may rely on distinct computational strategies for reinforcement learning, namely model-free vs. model-based learning. As a key theoretical difference, the model-based system strongly demands cognitive functions to plan actions prospectively based on an internal cognitive model of the environment, whereas valuation in the model-free system relies on rather simple learning rules from operant conditioning to retrospectively associate actions with their outcomes and is thus cognitively less demanding. Acute stress reactivity is known to impair model-based but not model-free choice behavior, with higher working memory capacity protecting the model-based system from acute stress. However, it is not clear which impact accumulated real life stress has on model-free and model-based decision systems and how this influence interacts with cognitive abilities. Methods: We used a sequential decision-making task distinguishing relative contributions of both learning strategies to choice behavior, the Social Readjustment Rating Scale questionnaire to assess accumulated real life stress, and the Digit Symbol Substitution Test to test cognitive speed in 95 healthy subjects. Results: Individuals reporting high stress exposure who had low cognitive speed showed reduced model-based but increased model-free behavioral control. In contrast, subjects exposed to accumulated real life stress with high cognitive speed displayed increased model-based performance but reduced model-free control. Conclusion: These findings suggest that accumulated real life stress exposure can enhance reliance on cognitive speed for model-based computations, which may ultimately protect the model-based system from the detrimental influences of accumulated real life stress. The combination of accumulated real life stress exposure and slower information processing capacities, however, might favor model-free strategies. Thus, the valence and preference of either system strongly depends on stressful experiences and individual cognitive capacities. PMID:28642696

How Accumulated Real Life Stress Experience and Cognitive Speed Interact on Decision-Making Processes.

PubMed

Friedel, Eva; Sebold, Miriam; Kuitunen-Paul, Sören; Nebe, Stephan; Veer, Ilya M; Zimmermann, Ulrich S; Schlagenhauf, Florian; Smolka, Michael N; Rapp, Michael; Walter, Henrik; Heinz, Andreas

2017-01-01

Rationale: Advances in neurocomputational modeling suggest that valuation systems for goal-directed (deliberative) on one side, and habitual (automatic) decision-making on the other side may rely on distinct computational strategies for reinforcement learning, namely model-free vs. model-based learning. As a key theoretical difference, the model-based system strongly demands cognitive functions to plan actions prospectively based on an internal cognitive model of the environment, whereas valuation in the model-free system relies on rather simple learning rules from operant conditioning to retrospectively associate actions with their outcomes and is thus cognitively less demanding. Acute stress reactivity is known to impair model-based but not model-free choice behavior, with higher working memory capacity protecting the model-based system from acute stress. However, it is not clear which impact accumulated real life stress has on model-free and model-based decision systems and how this influence interacts with cognitive abilities. Methods: We used a sequential decision-making task distinguishing relative contributions of both learning strategies to choice behavior, the Social Readjustment Rating Scale questionnaire to assess accumulated real life stress, and the Digit Symbol Substitution Test to test cognitive speed in 95 healthy subjects. Results: Individuals reporting high stress exposure who had low cognitive speed showed reduced model-based but increased model-free behavioral control. In contrast, subjects exposed to accumulated real life stress with high cognitive speed displayed increased model-based performance but reduced model-free control. Conclusion: These findings suggest that accumulated real life stress exposure can enhance reliance on cognitive speed for model-based computations, which may ultimately protect the model-based system from the detrimental influences of accumulated real life stress. The combination of accumulated real life stress exposure and slower information processing capacities, however, might favor model-free strategies. Thus, the valence and preference of either system strongly depends on stressful experiences and individual cognitive capacities.

Cognitive, emotion control, and motor performance of adolescents in the NCANDA study: Contributions from alcohol consumption, age, sex, ethnicity, and family history of addiction

PubMed Central

Sullivan, Edith V.; Brumback, Ty; Tapert, Susan F.; Fama, Rosemary; Prouty, Devin; Brown, Sandra A.; Cummins, Kevin; Thompson, Wesley K.; Colrain, Ian M.; Baker, Fiona C.; De Bellis, Michael D.; Hooper, Stephen R.; Clark, Duncan B.; Chung, Tammy; Nagel, Bonnie J.; Nichols, B. Nolan; Rohlfing, Torsten; Chu, Weiwei; Pohl, Kilian M.; Pfefferbaum, Adolf

2015-01-01

Objective To investigate development of cognitive and motor functions in healthy adolescents and to explore whether hazardous drinking affects the normal developmental course of those functions. Method Participants were 831 adolescents recruited across five United States sites of the National Consortium on Alcohol and NeuroDevelopment in Adolescence (NCANDA): 692 met criteria for no/low alcohol exposure, and 139 exceeded drinking thresholds. Cross-sectional, baseline data were collected with computerized and traditional neuropsychological tests assessing eight functional domains expressed as composite scores. General additive modeling evaluated factors potentially modulating performance (age, sex, ethnicity, socioeconomic status, and pubertal developmental stage). Results Older no/low-drinking participants achieved better scores than younger ones on five Accuracy composites (General Ability, Abstraction, Attention, Emotion, and Balance). Speeded responses for Attention, Motor Speed, and General Ability were sensitive to age and pubertal development. The exceeds-threshold group (accounting for age, sex, and other demographic factors) performed significantly below the no/low-drinking group on Balance accuracy and on General Ability, Attention, Episodic Memory, Emotion, and Motor speed scores and showed evidence for faster speed at the expense of accuracy. Delay Discounting performance was consistent with poor impulse control in the younger no/low drinkers and in exceeds-threshold drinkers regardless of age. Conclusions Higher achievement with older age and pubertal stage in General Ability, Abstraction, Attention, Emotion, and Balance suggests continued functional development through adolescence, possibly supported by concurrently maturing frontal, limbic, and cerebellar brain systems. Whether low scores by the exceeds-threshold group resulted from drinking or from other pre-existing factors requires longitudinal study. PMID:26752122

Cognitive, emotion control, and motor performance of adolescents in the NCANDA study: Contributions from alcohol consumption, age, sex, ethnicity, and family history of addiction.

PubMed

Sullivan, Edith V; Brumback, Ty; Tapert, Susan F; Fama, Rosemary; Prouty, Devin; Brown, Sandra A; Cummins, Kevin; Thompson, Wesley K; Colrain, Ian M; Baker, Fiona C; De Bellis, Michael D; Hooper, Stephen R; Clark, Duncan B; Chung, Tammy; Nagel, Bonnie J; Nichols, B Nolan; Rohlfing, Torsten; Chu, Weiwei; Pohl, Kilian M; Pfefferbaum, Adolf

2016-05-01

To investigate development of cognitive and motor functions in healthy adolescents and to explore whether hazardous drinking affects the normal developmental course of those functions. Participants were 831 adolescents recruited across 5 United States sites of the National Consortium on Alcohol and NeuroDevelopment in Adolescence 692 met criteria for no/low alcohol exposure, and 139 exceeded drinking thresholds. Cross-sectional, baseline data were collected with computerized and traditional neuropsychological tests assessing 8 functional domains expressed as composite scores. General additive modeling evaluated factors potentially modulating performance (age, sex, ethnicity, socioeconomic status, and pubertal developmental stage). Older no/low-drinking participants achieved better scores than younger ones on 5 accuracy composites (general ability, abstraction, attention, emotion, and balance). Speeded responses for attention, motor speed, and general ability were sensitive to age and pubertal development. The exceeds-threshold group (accounting for age, sex, and other demographic factors) performed significantly below the no/low-drinking group on balance accuracy and on general ability, attention, episodic memory, emotion, and motor speed scores and showed evidence for faster speed at the expense of accuracy. Delay Discounting performance was consistent with poor impulse control in the younger no/low drinkers and in exceeds-threshold drinkers regardless of age. Higher achievement with older age and pubertal stage in general ability, abstraction, attention, emotion, and balance suggests continued functional development through adolescence, possibly supported by concurrently maturing frontal, limbic, and cerebellar brain systems. Determination of whether low scores by the exceeds-threshold group resulted from drinking or from other preexisting factors requires longitudinal study. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Development of an Itemwise Efficiency Scoring Method: Concurrent, Convergent, Discriminant, and Neuroimaging-Based Predictive Validity Assessed in a Large Community Sample

PubMed Central

Moore, Tyler M.; Reise, Steven P.; Roalf, David R.; Satterthwaite, Theodore D.; Davatzikos, Christos; Bilker, Warren B.; Port, Allison M.; Jackson, Chad T.; Ruparel, Kosha; Savitt, Adam P.; Baron, Robert B.; Gur, Raquel E.; Gur, Ruben C.

2016-01-01

Traditional “paper-and-pencil” testing is imprecise in measuring speed and hence limited in assessing performance efficiency, but computerized testing permits precision in measuring itemwise response time. We present a method of scoring performance efficiency (combining information from accuracy and speed) at the item level. Using a community sample of 9,498 youths age 8-21, we calculated item-level efficiency scores on four neurocognitive tests, and compared the concurrent, convergent, discriminant, and predictive validity of these scores to simple averaging of standardized speed and accuracy-summed scores. Concurrent validity was measured by the scores' abilities to distinguish men from women and their correlations with age; convergent and discriminant validity were measured by correlations with other scores inside and outside of their neurocognitive domains; predictive validity was measured by correlations with brain volume in regions associated with the specific neurocognitive abilities. Results provide support for the ability of itemwise efficiency scoring to detect signals as strong as those detected by standard efficiency scoring methods. We find no evidence of superior validity of the itemwise scores over traditional scores, but point out several advantages of the former. The itemwise efficiency scoring method shows promise as an alternative to standard efficiency scoring methods, with overall moderate support from tests of four different types of validity. This method allows the use of existing item analysis methods and provides the convenient ability to adjust the overall emphasis of accuracy versus speed in the efficiency score, thus adjusting the scoring to the real-world demands the test is aiming to fulfill. PMID:26866796

Jump-Squat and Half-Squat Exercises: Selective Influences on Speed-Power Performance of Elite Rugby Sevens Players

PubMed Central

Loturco, Irineu; Pereira, Lucas A.; Moraes, José E.; Kitamura, Katia; Cal Abad, César C.; Kobal, Ronaldo; Nakamura, Fábio Y.

2017-01-01

The aim of this study was to evaluate the relation between the maximum mean propulsive power (MPP) obtained in the loaded jump squat (JS) and half squat (HS) exercises and functional performances in vertical jumps, 40 m linear speed (VEL) and change-of-direction (COD) tests, using the median split technique. Twenty-two male rugby sevens players from the Brazilian National Olympic Team (Rio-2016) performed vertical jumping tests (squat and countermovement jumps [SJ and CMJ]), JS and HS exercises, COD speed test and sprinting velocity in 40 m, in this order. Based on the results of the MPP in the JS and HS exercises the participants were divided, using the median split, into four groups as follows: higher JS, lower JS, higher HS, and lower HS. Between-group differences in the functional tasks were detected via magnitude-based inferences. The athletes with higher MPP in the JS were capable of jumping higher and sprinting faster (including the COD speed test) than their weaker counterparts. This pattern was not observed in the HS exercise. To conclude, JS was shown to be more connected to sprinting, COD speed and jumping abilities than HS in elite rugby sevens players and should be preferred for assessing and possibly training elite athletes needing to improve speed-power related abilities. PMID:28114431

Jump-Squat and Half-Squat Exercises: Selective Influences on Speed-Power Performance of Elite Rugby Sevens Players.

PubMed

Loturco, Irineu; Pereira, Lucas A; Moraes, José E; Kitamura, Katia; Cal Abad, César C; Kobal, Ronaldo; Nakamura, Fábio Y

2017-01-01

The aim of this study was to evaluate the relation between the maximum mean propulsive power (MPP) obtained in the loaded jump squat (JS) and half squat (HS) exercises and functional performances in vertical jumps, 40 m linear speed (VEL) and change-of-direction (COD) tests, using the median split technique. Twenty-two male rugby sevens players from the Brazilian National Olympic Team (Rio-2016) performed vertical jumping tests (squat and countermovement jumps [SJ and CMJ]), JS and HS exercises, COD speed test and sprinting velocity in 40 m, in this order. Based on the results of the MPP in the JS and HS exercises the participants were divided, using the median split, into four groups as follows: higher JS, lower JS, higher HS, and lower HS. Between-group differences in the functional tasks were detected via magnitude-based inferences. The athletes with higher MPP in the JS were capable of jumping higher and sprinting faster (including the COD speed test) than their weaker counterparts. This pattern was not observed in the HS exercise. To conclude, JS was shown to be more connected to sprinting, COD speed and jumping abilities than HS in elite rugby sevens players and should be preferred for assessing and possibly training elite athletes needing to improve speed-power related abilities.

Examining the influence of psychopathy, hostility biases, and automatic processing on criminal offenders' Theory of Mind.

PubMed

Nentjes, Lieke; Bernstein, David; Arntz, Arnoud; van Breukelen, Gerard; Slaats, Mariëtte

2015-01-01

Theory of Mind (ToM) is a social perceptual skill that refers to the ability to take someone else's perspective and infer what others think. The current study examined the effect of potential hostility biases, as well as controlled (slow) versus automatic (fast) processing on ToM performance in psychopathy. ToM abilities (as assessed with the Reading the Mind in the Eyes Test; RMET; Baron-Cohen, Wheelwright, Hill, Raste, & Plumb, 2001), was compared between 39 PCL-R diagnosed psychopathic offenders, 37 non-psychopathic offenders, and 26 nonoffender controls. Contrary to our hypothesis, psychopathic individuals presented with intact overall RMET performance when restrictions were imposed on how long task stimuli could be processed. In addition, psychopaths did not over-ascribe hostility to task stimuli (i.e., lack of hostility bias). However, there was a significant three-way interaction between hostility, processing speed, and psychopathy: when there was no time limit on stimulus presentation, psychopathic offenders made fewer errors in identifying more hostile eye stimuli compared to nonoffender controls, who seemed to be less accurate in detecting hostility. Psychopaths' more realistic appraisal of others' malevolent mental states is discussed in the light of theories that stress its potential adaptive function. Copyright © 2015 Elsevier Ltd. All rights reserved.

A Survey of Memristive Threshold Logic Circuits.

PubMed

Maan, Akshay Kumar; Jayadevi, Deepthi Anirudhan; James, Alex Pappachen

2017-08-01

In this paper, we review different memristive threshold logic (MTL) circuits that are inspired from the synaptic action of the flow of neurotransmitters in the biological brain. The brainlike generalization ability and the area minimization of these threshold logic circuits aim toward crossing Moore's law boundaries at device, circuits, and systems levels. Fast switching memory, signal processing, control systems, programmable logic, image processing, reconfigurable computing, and pattern recognition are identified as some of the potential applications of MTL systems. The physical realization of nanoscale devices with memristive behavior from materials, such as TiO 2 , ferroelectrics, silicon, and polymers, has accelerated research effort in these application areas, inspiring the scientific community to pursue the design of high-speed, low-cost, low-power, and high-density neuromorphic architectures.

Research on H2 speed governor for diesel engine of marine power station

NASA Astrophysics Data System (ADS)

Huang, Man-Lei

2007-09-01

The frequency stability of a marine power system is determined by the dynamic characteristic of the diesel engine speed regulation system in a marine power station. In order to reduce the effect of load disturbances and improve the dynamic precision of a diesel engine speed governor, a controller was designed for a diesel engine speed regulation system using H2 control theory. This transforms the specifications of the system into a standard H2 control problem. Firstly, the mathematical model of a diesel engine speed regulation system using an H2 speed governor is presented. To counter external disturbances and model uncertainty, the design of an H2 speed governor rests on the problem of mixed sensitivity. Computer simulation verified that the H2 speed governor improves the dynamic precision of a system and the ability to adapt to load disturbances, thus enhancing the frequency stability of marine power systems.

Design of video processing and testing system based on DSP and FPGA

NASA Astrophysics Data System (ADS)

Xu, Hong; Lv, Jun; Chen, Xi'ai; Gong, Xuexia; Yang, Chen'na

2007-12-01

Based on high speed Digital Signal Processor (DSP) and Field Programmable Gate Array (FPGA), a video capture, processing and display system is presented, which is of miniaturization and low power. In this system, a triple buffering scheme was used for the capture and display, so that the application can always get a new buffer without waiting; The Digital Signal Processor has an image process ability and it can be used to test the boundary of workpiece's image. A video graduation technology is used to aim at the position which is about to be tested, also, it can enhance the system's flexibility. The character superposition technology realized by DSP is used to display the test result on the screen in character format. This system can process image information in real time, ensure test precision, and help to enhance product quality and quality management.

NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 19: Computer and information technology and aerospace knowledge diffusion

NASA Technical Reports Server (NTRS)

Pinelli, Thomas E.; Kennedy, John M.; Barclay, Rebecca O.; Bishop, Ann P.

1992-01-01

To remain a world leader in aerospace, the US must improve and maintain the professional competency of its engineers and scientists, increase the research and development (R&D) knowledge base, improve productivity, and maximize the integration of recent technological developments into the R&D process. How well these objectives are met, and at what cost, depends on a variety of factors, but largely on the ability of US aerospace engineers and scientists to acquire and process the results of federally funded R&D. The Federal Government's commitment to high speed computing and networking systems presupposes that computer and information technology will play a major role in the aerospace knowledge diffusion process. However, we know little about information technology needs, uses, and problems within the aerospace knowledge diffusion process. The use of computer and information technology by US aerospace engineers and scientists in academia, government, and industry is reported.

Children's Increased Emotional Egocentricity Compared to Adults Is Mediated by Age-Related Differences in Conflict Processing.

PubMed

Hoffmann, Ferdinand; Singer, Tania; Steinbeis, Nikolaus

2015-01-01

This study investigated the cognitive mechanisms underlying age-related differences in emotional egocentricity bias (EEB) between children (aged 7-12 years, n = 30) and adults (aged 20-30 years, n = 30) using a novel paradigm of visuogustatory stimulation to induce pleasant and unpleasant emotions. Both children and adults showed an EBB, but that of children was larger. The EEB did not correlate with other measures of egocentricity. Crucially, the developmental differences in EEB were mediated by age-related changes in conflict processing and not visual perspective taking, response inhibition, or processing speed. This indicates that different types of egocentricity develop independently of one another and that the increased ability to overcome EEB can be explained by age-related improvements in conflict processing. © 2015 The Authors. Child Development © 2015 Society for Research in Child Development, Inc.

Fast and accurate edge orientation processing during object manipulation

PubMed Central

Flanagan, J Randall; Johansson, Roland S

2018-01-01

Quickly and accurately extracting information about a touched object’s orientation is a critical aspect of dexterous object manipulation. However, the speed and acuity of tactile edge orientation processing with respect to the fingertips as reported in previous perceptual studies appear inadequate in these respects. Here we directly establish the tactile system’s capacity to process edge-orientation information during dexterous manipulation. Participants extracted tactile information about edge orientation very quickly, using it within 200 ms of first touching the object. Participants were also strikingly accurate. With edges spanning the entire fingertip, edge-orientation resolution was better than 3° in our object manipulation task, which is several times better than reported in previous perceptual studies. Performance remained impressive even with edges as short as 2 mm, consistent with our ability to precisely manipulate very small objects. Taken together, our results radically redefine the spatial processing capacity of the tactile system. PMID:29611804

Combining Speed Information Across Space

NASA Technical Reports Server (NTRS)

Verghese, Preeti; Stone, Leland S.

1995-01-01

We used speed discrimination tasks to measure the ability of observers to combine speed information from multiple stimuli distributed across space. We compared speed discrimination thresholds in a classical discrimination paradigm to those in an uncertainty/search paradigm. Thresholds were measured using a temporal two-interval forced-choice design. In the discrimination paradigm, the n gratings in each interval all moved at the same speed and observers were asked to choose the interval with the faster gratings. Discrimination thresholds for this paradigm decreased as the number of gratings increased. This decrease was not due to increasing the effective stimulus area as a control experiment that increased the area of a single grating did not show a similar improvement in thresholds. Adding independent speed noise to each of the n gratings caused thresholds to decrease at a rate similar to the original no-noise case, consistent with observers combining an independent sample of speed from each grating in both the added- and no-noise cases. In the search paradigm, observers were asked to choose the interval in which one of the n gratings moved faster. Thresholds in this case increased with the number of gratings, behavior traditionally attributed to an input bottleneck. However, results from the discrimination paradigm showed that the increase was not due to observers' inability to process these gratings. We have also shown that the opposite trends of the data in the two paradigms can be predicted by a decision theory model that combines independent samples of speed information across space. This demonstrates that models typically used in classical detection and discrimination paradigms are also applicable to search paradigms. As our model does not distinguish between samples in space and time, it predicts that discrimination performance should be the same regardless of whether the gratings are presented in two spatial intervals or two temporal intervals. Our last experiment largely confirmed this prediction.

Understanding of Object Detection Based on CNN Family and YOLO

NASA Astrophysics Data System (ADS)

Du, Juan

2018-04-01

As a key use of image processing, object detection has boomed along with the unprecedented advancement of Convolutional Neural Network (CNN) and its variants since 2012. When CNN series develops to Faster Region with CNN (R-CNN), the Mean Average Precision (mAP) has reached 76.4, whereas, the Frame Per Second (FPS) of Faster R-CNN remains 5 to 18 which is far slower than the real-time effect. Thus, the most urgent requirement of object detection improvement is to accelerate the speed. Based on the general introduction to the background and the core solution CNN, this paper exhibits one of the best CNN representatives You Only Look Once (YOLO), which breaks through the CNN family’s tradition and innovates a complete new way of solving the object detection with most simple and high efficient way. Its fastest speed has achieved the exciting unparalleled result with FPS 155, and its mAP can also reach up to 78.6, both of which have surpassed the performance of Faster R-CNN greatly. Additionally, compared with the latest most advanced solution, YOLOv2 achieves an excellent tradeoff between speed and accuracy as well as an object detector with strong generalization ability to represent the whole image.

High-speed scanning of critical structures in aviation using coordinate measurement machine and the laser ultrasonic.

PubMed

Swornowski, Pawel J

2012-01-01

Aviation is one of the know-how spheres containing a great deal of responsible sub-assemblies, in this case landing gear. The necessity for reducing production cycle times while achieving better quality compels metrologists to look for new and improved ways to perform inspection of critical structures. This article describes the ability to determine the shape deviation and location of defects in landing gear using coordinate measuring machines and laser ultrasonic with high-speed scanning. A nondestructive test is the basis for monitoring microcrack and corrosion propagation in the context of a damage-tolerant design approach. This article presents an overview of the basics and of the various metrological aspects of coordinate measurement and a nondestructive testing method in terms of high-speed scanning. The new test method (laser ultrasonic) promises to produce the necessary increase in inspection quality, but this is limited by the wide range of materials, geometries, and structure aeronautic parts used. A technique combining laser ultrasonic and F-SAFT (Fourier-Synthetic Aperture Focusing Technique) processing has been proposed for the detection of small defects buried in landing gear. The experimental results of landing gear inspection are also presented. © Wiley Periodicals, Inc.

Relationship between anthropometry and motor abilities at pre-school age.

PubMed

De Toia, Daniela; Klein, Daniel; Weber, Sarah; Wessely, Nicolas; Koch, Benjamin; Tokarski, Walter; Dordel, Sigrid; Struder, Heiko; Graf, Christine

2009-01-01

Little is known to date about the relationship between poor motor abilities and overweight or obese pre-school children. Thus, this study examined the association between motor abilities and weight status in 1,228 kindergarten children (45.8% female). Anthropometric data were assessed; age 4.7 + or - 1.0 years; height 108.6 + or - 8.0 cm; weight 19.1 + or - 3.6 kg; BMI 16.1 + or - 1.5 kg/m(2). The modified Karlsruher Motor Ability Screening Test was carried out to determine the motor abilities of speed strength, muscular endurance, coordination, flexibility, and speed. Based on the German BMI reference values, 3.5% of the children were obese, 9.6% overweight, 83.4% normal weight, and 3.5% underweight. During various test tasks, below-average motor abilities were discovered in 44.0-47.3%. In all age groups, overweight and obese children did not differ from their normal and underweight counterparts; except for underweight children which fared worse in flexibility. In contrast to former studies with first graders, overweight or obese pre-school children did not possess worse motor abilities than normal weight children. However, the high number of overweight children and motor deficits suggests that preventive measures should start at this early age. Copyright 2009 S. Karger AG, Basel.

The Ability To Activate and Inhibit Speeded Responses: Separate Developmental Trends.

ERIC Educational Resources Information Center

Band, Guido P. H.; van der Molen, Maurits W.; Overtoom, Carin C. E.; Verbaten, Marinus N.

2000-01-01

Compared 5-, 8-, and 11-year-olds and young adults on 6 speeded performance tasks, 4 requiring an inhibition of response activation. Analyzed reaction and inhibition times; found support for hypothesis of generalized developmental changes in response activation, but revealed less pronounced development of inhibition. Concluded that a nonselective…

Item-Level Time Limits Are Not a Panacea

ERIC Educational Resources Information Center

Schmitz, Florian; Wilhelm, Oliver

2015-01-01

The excellent paper by Goldhammer (this issue) deals with a most relevant and very pervasive problem of ability assessment: the evaluation of performance by considering speed and accuracy of performance. Goldhammer proposes item-level time limits as a possible remedy for individual differences in the speed-accuracy trade-off (SATO) to keep time…

Response to various periods of mechanical stimuli in Physarum plasmodium

NASA Astrophysics Data System (ADS)

Umedachi, Takuya; Ito, Kentaro; Kobayashi, Ryo; Ishiguro, Akio; Nakagaki, Toshiyuki

2017-06-01

Response to mechanical stimuli is a fundamental and critical ability for living cells to survive in hazardous conditions or to form adaptive and functional structures against force(s) from the environment. Although this ability has been extensively studied by molecular biology strategies, it is also important to investigate the ability from the viewpoint of biological rhythm phenomena so as to reveal the mechanisms that underlie these phenomena. Here, we use the plasmodium of the true slime mold Physarum polycephalum as the experimental system for investigating this ability. The plasmodium was repetitively stretched for various periods during which its locomotion speed was observed. Since the plasmodium has inherent oscillation cycles of protoplasmic streaming and thickness variation, how the plasmodium responds to various periods of external stretching stimuli can shed light on the other biological rhythm phenomena. The experimental results show that the plasmodium exhibits response to periodic mechanical stimulation and changes its locomotion speed depending on the period of the stretching stimuli.

Matrix-vector multiplication using digital partitioning for more accurate optical computing

NASA Technical Reports Server (NTRS)

Gary, C. K.

1992-01-01

Digital partitioning offers a flexible means of increasing the accuracy of an optical matrix-vector processor. This algorithm can be implemented with the same architecture required for a purely analog processor, which gives optical matrix-vector processors the ability to perform high-accuracy calculations at speeds comparable with or greater than electronic computers as well as the ability to perform analog operations at a much greater speed. Digital partitioning is compared with digital multiplication by analog convolution, residue number systems, and redundant number representation in terms of the size and the speed required for an equivalent throughput as well as in terms of the hardware requirements. Digital partitioning and digital multiplication by analog convolution are found to be the most efficient alogrithms if coding time and hardware are considered, and the architecture for digital partitioning permits the use of analog computations to provide the greatest throughput for a single processor.

Concepts and application of dynamic separation for agility and super-maneuverability of aircraft: An assessment

NASA Technical Reports Server (NTRS)

Freymuth, Peter

1992-01-01

Aims for improvement of fighter aircraft pursued by the unsteady flow community are high agility (the ability of the aircraft to make close turns in a low-speed regime) and super maneuverability (the ability of the aircraft to operate at high angles of attack in a post stall regime during quick maneuvers in a more extended speed range). High agility requires high lift coefficients at low speeds in a dynamic situation and this requirement can be met by dynamically forced separation or by quasistatic stall control. The competing methods will be assessed based on the known physics. Maneuvering into the post stall regime also involves dynamic separation but because even fast maneuvers involving the entire aircraft are 'aerodynamically slow' the resulting dynamic vortex structures should be considered 'elicited' rather than 'forced.' More work seems to be needed in this area of elicited dynamic separation.

Running energetics in the pronghorn antelope.

PubMed

Lindstedt, S L; Hokanson, J F; Wells, D J; Swain, S D; Hoppeler, H; Navarro, V

1991-10-24

The pronghorn antelope (Antilocapra americana) has an alleged top speed of 100 km h-1, second only to the cheetah (Acionyx jubatus) among land vertebrates, a possible response to predation in the exposed habitat of the North American prairie. Unlike cheetahs, however, pronghorn antelope are distance runners rather than sprinters, and can run 11 km in 10 min, an average speed of 65 km h-1. We measured maximum oxygen uptake in pronghorn antelope to distinguish between two potential explanations for this ability: either they have evolved a uniquely high muscular efficiency (low cost of transport) or they can supply oxygen to the muscles at unusually high levels. Because the cost of transport (energy per unit distance covered per unit body mass) varies as a predictable function of body mass among terrestrial vertebrates, we can calculate the predicted cost to maintain speeds of 65 and 100 km h-1 in an average 32-kg animal. The resulting range of predicted values, 3.2-5.1 ml O2 kg-1 s-1, far surpasses the predicted maximum aerobic capacity of a 32-kg mammal (1.5 ml O2 kg-1 s-1). We conclude that their performance is achieved by an extraordinary capacity to consume and process enough oxygen to support a predicted running speed greater than 20 ms-1 (70 km h-1), attained without unique respiratory-system structures.

Methods for Processing and Interpretation of AIS Signals Corrupted by Noise and Packet Collisions

NASA Astrophysics Data System (ADS)

Poļevskis, J.; Krastiņš, M.; Korāts, G.; Skorodumovs, A.; Trokšs, J.

2012-01-01

The authors deal with the operation of Automatic Identification System (AIS) used in the marine traffic monitoring to broadcast messages containing information about the vessel: id, payload, size, speed, destination etc., meant primarily for avoidance of ship collisions. To extend the radius of AIS operation, it is envisaged to dispose its receivers on satellites. However, in space, due to a large coverage area, interfering factors are especially pronounced - such as packet collision, Doppler's shift and noise impact on AIS message receiving, pre-processing and decoding. To assess the quality of an AIS receiver's operation, a test was carried out in which, varying automatically frequency, amplitude, noise, and other parameters, the data on the ability of the receiver's ability to decode AIS signals are collected. In the work, both hardware- and software-based AIS decoders were tested. As a result, quite satisfactory statistics has been gathered - both on the common and the differing features of such decoders when operating in space. To obtain reliable data on the software-defined radio AIS receivers, further research is envisaged.

RysannMD: A biomedical semantic annotator balancing speed and accuracy.

PubMed

Cuzzola, John; Jovanović, Jelena; Bagheri, Ebrahim

2017-07-01

Recently, both researchers and practitioners have explored the possibility of semantically annotating large and continuously evolving collections of biomedical texts such as research papers, medical reports, and physician notes in order to enable their efficient and effective management and use in clinical practice or research laboratories. Such annotations can be automatically generated by biomedical semantic annotators - tools that are specifically designed for detecting and disambiguating biomedical concepts mentioned in text. The biomedical community has already presented several solid automated semantic annotators. However, the existing tools are either strong in their disambiguation capacity, i.e., the ability to identify the correct biomedical concept for a given piece of text among several candidate concepts, or they excel in their processing time, i.e., work very efficiently, but none of the semantic annotation tools reported in the literature has both of these qualities. In this paper, we present RysannMD (Ryerson Semantic Annotator for Medical Domain), a biomedical semantic annotation tool that strikes a balance between processing time and performance while disambiguating biomedical terms. In other words, RysannMD provides reasonable disambiguation performance when choosing the right sense for a biomedical term in a given context, and does that in a reasonable time. To examine how RysannMD stands with respect to the state of the art biomedical semantic annotators, we have conducted a series of experiments using standard benchmarking corpora, including both gold and silver standards, and four modern biomedical semantic annotators, namely cTAKES, MetaMap, NOBLE Coder, and Neji. The annotators were compared with respect to the quality of the produced annotations measured against gold and silver standards using precision, recall, and F 1 measure and speed, i.e., processing time. In the experiments, RysannMD achieved the best median F 1 measure across the benchmarking corpora, independent of the standard used (silver/gold), biomedical subdomain, and document size. In terms of the annotation speed, RysannMD scored the second best median processing time across all the experiments. The obtained results indicate that RysannMD offers the best performance among the examined semantic annotators when both quality of annotation and speed are considered simultaneously. Copyright © 2017 Elsevier Inc. All rights reserved.

Fast and slow readers of the Hebrew language show divergence in brain response ∼200 ms post stimulus: an ERP study.

PubMed

Korinth, Sebastian Peter; Breznitz, Zvia

2014-01-01

Higher N170 amplitudes to words and to faces were recently reported for faster readers of German. Since the shallow German orthography allows phonological recoding of single letters, the reported speed advantages might have their origin in especially well-developed visual processing skills of faster readers. In contrast to German, adult readers of Hebrew are forced to process letter chunks up to whole words. This dependence on more complex visual processing might have created ceiling effects for this skill. Therefore, the current study examined whether also in the deep Hebrew orthography visual processing skills as reflected by N170 amplitudes explain reading speed differences. Forty university students, native speakers of Hebrew without reading impairments, accomplished a lexical decision task (i.e., deciding whether a visually presented stimulus represents a real or a pseudo word) and a face decision task (i.e., deciding whether a face was presented complete or with missing facial features) while their electroencephalogram was recorded from 64 scalp positions. In both tasks stronger event related potentials (ERPs) were observed for faster readers in time windows at about 200 ms. Unlike in previous studies, ERP waveforms in relevant time windows did not correspond to N170 scalp topographies. The results support the notion of visual processing ability as an orthography independent marker of reading proficiency, which advances our understanding about regular and impaired reading development.

Relationship Between Change of Direction, Speed and Power in Male and Female National Olympic Team Handball Athletes.

PubMed

Pereira, Lucas A; Nimphius, Sophia; Kobal, Ronaldo; Kitamura, Katia; Turisco, Luiz A L; Orsi, Rita C; Cal Abad, César Cs; Loturco, Irineu

2018-02-22

The aims of this study were to (1) assess the relationship between selected speed-power related abilities (determined by 20-m sprint, unloaded countermovement and squat jumps [CMJ and SJ] and loaded jump squat [JS]) and performance in two distinct change of direction (COD) protocols (Zigzag and T-Test), and (2) determine the magnitude of difference between female and male Brazilian National Olympic Team handball athletes. Fifteen male and twenty-three female elite handball athletes volunteered to perform the following assessments: SJ and CMJ; Zigzag and T-Test; 20-m sprint with 5-, 10-, and 20-m splits, and mean propulsive power (MPP) in JS. Pearson product moment correlation (P< 0.05) was performed to determine the relationship between the COD tests (Zigzag and T-test) and speed-power measures (sprint, SJ, CMJ and JS). The differences between male and female performances were determined using the magnitude-based inference. Moderate to very large significant correlations were observed between both COD tests and the speed-power abilities. Further, male athletes demonstrated likely to almost certainly higher performances than female athletes in all assessed variables. The results of the current study suggest that different speed-power qualities are strongly correlated to the performance obtained in various COD assessments (r values varying from 0.38 to 0.84 and from 0.34 to 0.84 for correlations between speed and power tests with Zigzag and T-Test, respectively). However, the level of these associations can vary greatly, according to the mechanical demands of each respective COD task. Whilst COD tests may be difficult to implement during competitive seasons, due to the strong correlations presented herein, the regular use of vertical jump tests with these athletes seems to be an effective and applied alternative. Furthermore, it might be inferred that the proper development of loaded and unloaded jump abilities has potential for improving the physical qualities related to COD performance in handball athletes.

Determinants of Slow Walking Speed in Ambulatory Patients Undergoing Maintenance Hemodialysis

PubMed Central

Matsuzawa, Ryota; Kutsuna, Toshiki; Yamamoto, Shuhei; Yoneki, Kei; Harada, Manae; Ishikawa, Ryoma; Watanabe, Takaaki; Yoshida, Atsushi

2016-01-01

Walking ability is significantly lower in hemodialysis patients compared to healthy people. Decreased walking ability characterized by slow walking speed is associated with adverse clinical events, but determinants of decreased walking speed in hemodialysis patients are unknown. The purpose of this study was to identify factors associated with slow walking speed in ambulatory hemodialysis patients. Subjects were 122 outpatients (64 men, 58 women; mean age, 68 years) undergoing hemodialysis. Clinical characteristics including comorbidities, motor function (strength, flexibility, and balance), and maximum walking speed (MWS) were measured and compared across sex-specific tertiles of MWS. Univariate and multivariate logistic regression analyses were performed to examine whether clinical characteristics and motor function could discriminate between the lowest, middle, and highest tertiles of MWS. Significant and common factors that discriminated the lowest and highest tertiles of MWS from other categories were presence of cardiac disease (lowest: odds ratio [OR] = 3.33, 95% confidence interval [CI] = 1.26–8.83, P<0.05; highest: OR = 2.84, 95% CI = 1.18–6.84, P<0.05), leg strength (OR = 0.62, 95% CI = 0.40–0.95, P<0.05; OR = 0.57, 95% CI = 0.39–0.82, P<0.01), and standing balance (OR = 0.76, 95% CI = 0.63–0.92, P<0.01; OR = 0.81, 95% CI = 0.68–0.97, P<0.05). History of fracture (OR = 3.35, 95% CI = 1.08–10.38; P<0.05) was a significant factor only in the lowest tertile. Cardiac disease, history of fracture, decreased leg strength, and poor standing balance were independently associated with slow walking speed in ambulatory hemodialysis patients. These findings provide useful data for planning effective therapeutic regimens to prevent decreases in walking ability in ambulatory hemodialysis patients. PMID:27018891

Investigation of extinction and re-ignition in piloted turbulent non-premixed methane-air flames using LES and high-speed OH-LIF

NASA Astrophysics Data System (ADS)

Prasad, Vinayaka N.; Juddoo, Mrinal; Masri, Assaad R.; Jones, William P.; Luo, Kai H.

2013-06-01

Extinction and re-ignition processes observed experimentally in thin reaction zones of piloted turbulent non-premixed methane flames approaching blow-off are analysed using Large Eddy Simulation (LES) along with the Eulerian stochastic field method representing the unresolved sub-grid turbulence-chemistry interactions. Eight stochastic fields in conjunction with a reduced chemical mechanism involving 19 species are employed to perform simulations of the Sydney flames L, B and M, which exhibit increasing levels of extinction. The agreement of the flame statistics of the velocities, mixture fraction and selected reactive species were found to be encouraging and highlight the ability of the method to capture quantitatively the effects of increasing jet velocity in this series. In a subsequent analysis of the flame structure using the LES simulation data, the strong three-dimensionality of the flame was emphasised. Quantitative comparisons with recent measurements using high-speed Planar Laser-Induced Fluorescence of OH (OH-PLIF) were found to be in reasonably good agreement with LES simulations and confirm the previous observations that the rates of flame breakages are greater than those of flame closures. This study, which also represents the first successful numerical attempt to describe the entire flame series, highlights the potential and complementary capabilities of a hybrid LES and high-speed imaging approach to resolve issues such as the role of out-of-plane motion in the investigation of transient processes such as flame breakages and re-ignition.

Evaluation of selected properties of gluten-free instant gruels processed under various extrusion-cook- ing conditions.

PubMed

Kręcisz, Magdalena; Wójtowicz, Agnieszka

2017-01-01

For consumers suffering with gluten intolerance, the only way to manage the condition is to avoid foods which are high in gluten. Instant gruels, processed from gluten-free corn and rice by extrusion cooking, could be used as a ready meal both for children and for adults on a gluten-free diet. The aim of the study was to evaluate the effects of various processing conditions on selected characteristics of corn-rice instant gruels. Corn-rice mixtures (75:25 and 50:50) were processed at 12, 14, 16 and 18% of initial moisture content, using an extruder with screw speeds of 80, 100 and 120 rpm. Bulk density, water absorption and solubility, gel formation, color and sensory characteristics were assessed, under various pro- cessing conditions and with various corn:rice ratios. The composition of the raw materials, initial moisture content and screw speed applied during processing affected the characteristics of the corn-rice extruded instant gruels. Increasing the amount of rice in the recipe from 25 to 50% resulted in decreased bulk density, water solubility, volumetric gel formation ability and b* value. Increasing the initial moisture content increased the bulk density, L*, a* and b* intensity, and gel formation index values of extrudates made with a 75:25 corn-rice recipe. Increased rpm increased extrudate solubility and water absorption, if the initial moisture content was higher than 14%. The highest scores for overall acceptability were found for milk suspensions of 75:25 and 50:50 corn-rice instant gruels processed at 12 and 14% of initial moisture content, at 120 rpm. Corn-rice instant gruels can be successfully produced by extrusion-cooking. Variable param- eters, like the initial moisture content of raw materials or screw speed during processing significantly affected the properties of the products. An understanding of the effects of processing conditions on some qualities of extruded instant gruels allows more desirable products to be created. Moreover, the various components can be used for extruded products for consumers on gluten-free diets. Functional additives incorporated in the recipe to improve the nutritional value of the extrudates, which will be investigated in our upcoming research.

THE EFFECTS OF SYSTEMATIC VARIATION OF SPEED AND DIRECTION OF OBJECT FLIGHT AND OF SKILL AND AGE CLASSIFICATIONS UPON VISUO-PERCEPTUAL JUDGMENTS OF MOVING OBJECTS IN THREE-DIMENSIONAL SPACE. FINAL REPORT.

ERIC Educational Resources Information Center

WILLIAMS, HARRIET G.

THIS STUDY WAS CONDUCTED TO INVESTIGATE THE EFFECTS OF VARIATIONS IN THE SPEED AND DIRECTION OF A FLYING OBJECT ON VISUO-PERCEPTUAL JUDGMENTS MADE, DIFFERENCES IN THE ABILITY OF SKILLED AND UNSKILLED SUBJECTS IN MAKING SUCH JUDGMENTS, AND THE EFFECTS OF AGE OR MATURITY LEVEL ON THE SPEED AND ACCURACY OF SUCH JUDGMENTS. THE SUBJECTS WERE 54 MALE…

Latent profile analysis of regression-based norms demonstrates relationship of compounding MS symptom burden and negative work events.

PubMed

Frndak, Seth E; Smerbeck, Audrey M; Irwin, Lauren N; Drake, Allison S; Kordovski, Victoria M; Kunker, Katrina A; Khan, Anjum L; Benedict, Ralph H B

2016-10-01

We endeavored to clarify how distinct co-occurring symptoms relate to the presence of negative work events in employed multiple sclerosis (MS) patients. Latent profile analysis (LPA) was utilized to elucidate common disability patterns by isolating patient subpopulations. Samples of 272 employed MS patients and 209 healthy controls (HC) were administered neuroperformance tests of ambulation, hand dexterity, processing speed, and memory. Regression-based norms were created from the HC sample. LPA identified latent profiles using the regression-based z-scores. Finally, multinomial logistic regression tested for negative work event differences among the latent profiles. Four profiles were identified via LPA: a common profile (55%) characterized by slightly below average performance in all domains, a broadly low-performing profile (18%), a poor motor abilities profile with average cognition (17%), and a generally high-functioning profile (9%). Multinomial regression analysis revealed that the uniformly low-performing profile demonstrated a higher likelihood of reported negative work events. Employed MS patients with co-occurring motor, memory and processing speed impairments were most likely to report a negative work event, classifying them as uniquely at risk for job loss.

Speeding Up Geophysical Research Using Docker Containers Within Multi-Cloud Environment.

NASA Astrophysics Data System (ADS)

Synytsky, R.; Henadiy, S.; Lobzakov, V.; Kolesnikov, L.; Starovoit, Y. O.

2016-12-01

How useful are the geophysical observations in a scope of minimizing losses from natural disasters today? Does it help to decrease number of human victims during tsunami and earthquake? Unfortunately it's still at early stage these days. It's a big goal and achievement to make such observations more useful by improving early warning and prediction systems with the help of cloud computing. Cloud computing technologies have proved the ability to speed up application development in many areas for 10 years already. Cloud unlocks new opportunities for geoscientists by providing access to modern data processing tools and algorithms including real-time high-performance computing, big data processing, artificial intelligence and others. Emerging lightweight cloud technologies, such as Docker containers, are gaining wide traction in IT due to the fact of faster and more efficient deployment of different applications in a cloud environment. It allows to deploy and manage geophysical applications and systems in minutes across multiple clouds and data centers that becomes of utmost importance for the next generation applications. In this session we'll demonstrate how Docker containers technology within multi-cloud can accelerate the development of applications specifically designed for geophysical researches.

Differences in arithmetic performance between Chinese and German adults are accompanied by differences in processing of non-symbolic numerical magnitude

PubMed Central

Lonnemann, Jan; Li, Su; Zhao, Pei; Li, Peng; Linkersdörfer, Janosch; Lindberg, Sven; Hasselhorn, Marcus; Yan, Song

2017-01-01

Human beings are assumed to possess an approximate number system (ANS) dedicated to extracting and representing approximate numerical magnitude information. The ANS is assumed to be fundamental to arithmetic learning and has been shown to be associated with arithmetic performance. It is, however, still a matter of debate whether better arithmetic skills are reflected in the ANS. To address this issue, Chinese and German adults were compared regarding their performance in simple arithmetic tasks and in a non-symbolic numerical magnitude comparison task. Chinese participants showed a better performance in solving simple arithmetic tasks and faster reaction times in the non-symbolic numerical magnitude comparison task without making more errors than their German peers. These differences in performance could not be ascribed to differences in general cognitive abilities. Better arithmetic skills were thus found to be accompanied by a higher speed of retrieving non-symbolic numerical magnitude knowledge but not by a higher precision of non-symbolic numerical magnitude representations. The group difference in the speed of retrieving non-symbolic numerical magnitude knowledge was fully mediated by the performance in arithmetic tasks, suggesting that arithmetic skills shape non-symbolic numerical magnitude processing skills. PMID:28384191

Individual Differences in Algebraic Cognition: Relation to the Approximate Number and Sematic Memory Systems

PubMed Central

Geary, David C.; Hoard, Mary K.; Nugent, Lara; Rouder, Jeffrey N.

2015-01-01

The relation between performance on measures of algebraic cognition and acuity of the approximate number system (ANS) and memory for addition facts was assessed for 171 (92 girls) 9th graders, controlling parental education, sex, reading achievement, speed of numeral processing, fluency of symbolic number processing, intelligence, and the central executive component of working memory. The algebraic tasks assessed accuracy in placing x,y pairs in the coordinate plane, speed and accuracy of expression evaluation, and schema memory for algebra equations. ANS acuity was related to accuracy of placements in the coordinate plane and expression evaluation, but not schema memory. Frequency of fact-retrieval errors was related to schema memory but not coordinate plane or expression evaluation accuracy. The results suggest the ANS may contribute to or is influenced by spatial-numerical and numerical only quantity judgments in algebraic contexts, whereas difficulties in committing addition facts to long-term memory may presage slow formation of memories for the basic structure of algebra equations. More generally, the results suggest different brain and cognitive systems are engaged during the learning of different components of algebraic competence, controlling demographic and domain general abilities. PMID:26255604

Neurological and Psychiatric Diseases and Their Unique Cognitive Profiles: Implications for Nursing Practice and Research

PubMed Central

Vance, David E.; Dodson, Joan E.; Watkins, Jason; Kennedy, Bridgett H.; Keltner, Norman L.

2013-01-01

To successfully negotiate and interact with one’s environment, optimal cognitive functioning is needed. Unfortunately, many neurological and psychiatric diseases impede certain cognitive abilities such as executive functioning or speed of processing; this can produce a poor fit between the patient and the cognitive demands of his or her environment. Such non-dementia diseases include bipolar disorder, schizophrenia, post-traumatic stress syndrome, depression, and anxiety disorders, just to name a few. Each of these diseases negatively affects particular areas of the brain, resulting in distinct cognitive profiles (e.g., deficits in executive functioning but normal speed of processing as seen in schizophrenia). In fact, it is from these cognitive deficits in which such behavioral and emotional symptoms may manifest (e.g., delusions, paranoia). This article highlights the distinct cognitive profiles of such common neurological and psychiatric diseases. An understanding of such disease-specific cognitive profiles can assist nurses in providing care to patients by knowing what cognitive deficits are associated with each disease and how these cognitive deficits impact everyday functioning and social interactions. Implications for nursing practice and research are posited within the framework of cognitive reserve and neuroplasticity. PMID:23422693

Affective-cognitive meta-bases versus structural bases of attitudes predict processing interest versus efficiency.

PubMed

See, Ya Hui Michelle; Petty, Richard E; Fabrigar, Leandre R

2013-08-01

We proposed that (a) processing interest for affective over cognitive information is captured by meta-bases (i.e., the extent to which people subjectively perceive themselves to rely on affect or cognition in their attitudes) and (b) processing efficiency for affective over cognitive information is captured by structural bases (i.e., the extent to which attitudes are more evaluatively congruent with affect or cognition). Because processing speed can disentangle interest from efficiency by being manifest as longer or shorter reading times, we hypothesized and found that more affective meta-bases predicted longer affective than cognitive reading time when processing efficiency was held constant (Study 1). In contrast, more affective structural bases predicted shorter affective than cognitive reading time when participants were constrained in their ability to allocate resources deliberatively (Study 2). When deliberation was neither encouraged nor constrained, effects for meta-bases and structural bases emerged (Study 3). Implications for affective-cognitive processing and other attitudes-relevant constructs are discussed.

Computational Modeling in Structural Materials Processing

NASA Technical Reports Server (NTRS)

Meyyappan, Meyya; Arnold, James O. (Technical Monitor)

1997-01-01

High temperature materials such as silicon carbide, a variety of nitrides, and ceramic matrix composites find use in aerospace, automotive, machine tool industries and in high speed civil transport applications. Chemical vapor deposition (CVD) is widely used in processing such structural materials. Variations of CVD include deposition on substrates, coating of fibers, inside cavities and on complex objects, and infiltration within preforms called chemical vapor infiltration (CVI). Our current knowledge of the process mechanisms, ability to optimize processes, and scale-up for large scale manufacturing is limited. In this regard, computational modeling of the processes is valuable since a validated model can be used as a design tool. The effort is similar to traditional chemically reacting flow modeling with emphasis on multicomponent diffusion, thermal diffusion, large sets of homogeneous reactions, and surface chemistry. In the case of CVI, models for pore infiltration are needed. In the present talk, examples of SiC nitride, and Boron deposition from the author's past work will be used to illustrate the utility of computational process modeling.

Behavior problems in children at time of first recognized seizure and changes over the following 3 years.

PubMed

Austin, J K; Perkins, S M; Johnson, C S; Fastenau, P S; Byars, A W; deGrauw, T J; Dunn, D W

2011-08-01

The purposes of this 36-month study of children with first recognized seizures were: (1) to describe baseline differences in behavior problems between children with and without prior unrecognized seizures; (2) to identify differences over time in behavior problems between children with seizures and their healthy siblings; (3) to identify the proportions of children with seizures and healthy siblings who were consistently at risk for behavior problems for 36 months; and (4) to identify risk factors for behavior problems 36 months following the first recognized seizure. Risk factors explored included demographic (child age and gender, caregiver education), neuropsychological (IQ, processing speed), seizure (epileptic syndrome, use of antiepileptic drug, seizure recurrence), and family (family mastery, satisfaction with family relationships, parent response) variables. Participants were 300 children aged 6 through 14 years with a first recognized seizure and 196 healthy siblings. Data were collected from medical records, structured interviews, self-report questionnaires, and neuropsychological testing. Behavior problems were measured using the Child Behavior Checklist and the Teacher's Report Form. Data analyses included descriptive statistics and linear mixed models. Children with prior unrecognized seizures were at higher risk for behavior problems at baseline. As a group, children with seizures showed a steady reduction in behavior problems over time. Children with seizures were found to have significantly more behavior problems than their siblings over time, and significantly more children with seizures (11.3%) than siblings (4.6%) had consistent behavior problems over time. Key risk factors for child behavior problems based on both caregivers and teachers were: less caregiver education, slower initial processing speed, slowing of processing speed over the first 36 months, and a number of family variables including lower levels of family mastery or child satisfaction with family relationships, lower parent support of the child's autonomy, and lower parent confidence in their ability to discipline their child. Children with new-onset seizures who are otherwise developing normally have higher rates of behavior problems than their healthy siblings; however, behavior problems are not consistently in the at-risk range in most children during the first 3 years after seizure onset. When children show behavior problems, family variables that might be targeted include family mastery, parent support of child autonomy, and parents' confidence in their ability to handle their children's behavior.

Rapid Automatized Naming in Children with Dyslexia: Is Inhibitory Control Involved?

PubMed

Bexkens, Anika; van den Wildenberg, Wery P M; Tijms, Jurgen

2015-08-01

Rapid automatized naming (RAN) is widely seen as an important indicator of dyslexia. The nature of the cognitive processes involved in rapid naming is however still a topic of controversy. We hypothesized that in addition to the involvement of phonological processes and processing speed, RAN is a function of inhibition processes, in particular of interference control. A total 86 children with dyslexia and 31 normal readers were recruited. Our results revealed that in addition to phonological processing and processing speed, interference control predicts rapid naming in dyslexia, but in contrast to these other two cognitive processes, inhibition is not significantly associated with their reading and spelling skills. After variance in reading and spelling associated with processing speed, interference control and phonological processing was partialled out, naming speed was no longer consistently associated with the reading and spelling skills of children with dyslexia. Finally, dyslexic children differed from normal readers on naming speed, literacy skills, phonological processing and processing speed, but not on inhibition processes. Both theoretical and clinical interpretations of these results are discussed. Copyright © 2014 John Wiley & Sons, Ltd.

Meaningful improvement in gait speed in hip fracture recovery.

PubMed

Alley, Dawn E; Hicks, Gregory E; Shardell, Michelle; Hawkes, William; Miller, Ram; Craik, Rebecca L; Mangione, Kathleen K; Orwig, Denise; Hochberg, Marc; Resnick, Barbara; Magaziner, Jay

2011-09-01

To estimate meaningful improvements in gait speed observed during recovery from hip fracture and to evaluate the sensitivity and specificity of gait speed changes in detecting change in self-reported mobility. Secondary longitudinal data analysis from two randomized controlled trials Twelve hospitals in the Baltimore, Maryland, area. Two hundred seventeen women admitted with hip fracture. Usual gait speed and self-reported mobility (ability to walk 1 block and climb 1 flight of stairs) measured 2 and 12 months after fracture. Effect size-based estimates of meaningful differences were 0.03 for small differences and 0.09 for substantial differences. Depending on the anchor (stairs vs walking) and method (mean difference vs regression), anchor-based estimates ranged from 0.10 to 0.17 m/s for small meaningful improvements and 0.17 to 0.26 m/s for substantial meaningful improvement. Optimal gait speed cutpoints yielded low sensitivity (0.39-0.62) and specificity (0.57-0.76) for improvements in self-reported mobility. Results from this sample of women recovering from hip fracture provide only limited support for the 0.10-m/s cut point for substantial meaningful change previously identified in community-dwelling older adults experiencing declines in walking abilities. Anchor-based estimates and cut points derived from receiver operating characteristic curve analysis suggest that greater improvements in gait speed may be required for substantial perceived mobility improvement in female hip fracture patients. Furthermore, gait speed change performed poorly in discriminating change in self-reported mobility. Estimates of meaningful change in gait speed may differ based on the direction of change (improvement vs decline) or between patient populations. © 2011, Copyright the Authors. Journal compilation © 2011, The American Geriatrics Society.

Meaningful Improvement in Gait Speed in Hip Fracture Recovery

PubMed Central

Alley, Dawn E.; Hicks, Gregory E.; Shardell, Michelle; Hawkes, William; Miller, Ram; Craik, Rebecca L.; Mangione, Kathleen K.; Orwig, Denise; Hochberg, Marc; Resnick, Barbara; Magaziner, Jay

2011-01-01

OBJECTIVES To estimate meaningful improvements in gait speed observed during recovery from hip fracture and to evaluate the sensitivity and specificity of gait speed changes in detecting change in self-reported mobility. DESIGN Secondary longitudinal data analysis from two randomized controlled trials SETTING Twelve hospitals in the Baltimore, Maryland, area. PARTICIPANTS Two hundred seventeen women admitted with hip fracture. MEASUREMENTS Usual gait speed and self-reported mobility (ability to walk 1 block and climb 1 flight of stairs) measured 2 and 12 months after fracture. RESULTS Effect size–based estimates of meaningful differences were 0.03 for small differences and 0.09 for substantial differences. Depending on the anchor (stairs vs walking) and method (mean difference vs regression), anchor-based estimates ranged from 0.10 to 0.17 m/s for small meaningful improvements and 0.17 to 0.26 m/s for substantial meaningful improvement. Optimal gait speed cut-points yielded low sensitivity (0.39–0.62) and specificity (0.57–0.76) for improvements in self-reported mobility. CONCLUSION Results from this sample of women recovering from hip fracture provide only limited support for the 0.10-m/s cut point for substantial meaningful change previously identified in community-dwelling older adults experiencing declines in walking abilities. Anchor-based estimates and cut points derived from receiver operating characteristic curve analysis suggest that greater improvements in gait speed may be required for substantial perceived mobility improvement in female hip fracture patients. Furthermore, gait speed change performed poorly in discriminating change in self-reported mobility. Estimates of meaningful change in gait speed may differ based on the direction of change (improvement vs decline) or between patient populations. PMID:21883109

Brain-behavioral adaptability predicts response to cognitive behavioral therapy for emotional disorders: A person-centered event-related potential study.

PubMed

Stange, Jonathan P; MacNamara, Annmarie; Kennedy, Amy E; Hajcak, Greg; Phan, K Luan; Klumpp, Heide

2017-06-23

Single-trial-level analyses afford the ability to link neural indices of elaborative attention (such as the late positive potential [LPP], an event-related potential) with downstream markers of attentional processing (such as reaction time [RT]). This approach can provide useful information about individual differences in information processing, such as the ability to adapt behavior based on attentional demands ("brain-behavioral adaptability"). Anxiety and depression are associated with maladaptive information processing implicating aberrant cognition-emotion interactions, but whether brain-behavioral adaptability predicts response to psychotherapy is not known. We used a novel person-centered, trial-level analysis approach to link neural indices of stimulus processing to behavioral responses and to predict treatment outcome. Thirty-nine patients with anxiety and/or depression received 12 weeks of cognitive behavioral therapy (CBT). Prior to treatment, patients performed a speeded reaction-time task involving briefly-presented pairs of aversive and neutral pictures while electroencephalography was recorded. Multilevel modeling demonstrated that larger LPPs predicted slower responses on subsequent trials, suggesting that increased attention to the task-irrelevant nature of pictures interfered with reaction time on subsequent trials. Whereas using LPP and RT averages did not distinguish CBT responders from nonresponders, in trial-level analyses individuals who demonstrated greater ability to benefit behaviorally (i.e., faster RT) from smaller LPPs on the previous trial (greater brain-behavioral adaptability) were more likely to respond to treatment and showed greater improvements in depressive symptoms. These results highlight the utility of trial-level analyses to elucidate variability in within-subjects, brain-behavioral attentional coupling in the context of emotion processing, in predicting response to CBT for emotional disorders. Copyright © 2017 Elsevier Ltd. All rights reserved.

Longitudinal Processing Speed Impairments in Males with Autism and the Effects of White Matter Microstructure

PubMed Central

Travers, Brittany G.; Bigler, Erin D.; Tromp, Do P. M.; Adluru, Nagesh; Froehlich, Alyson L.; Ennis, Chad; Lange, Nicholas; Nielsen, Jared A.; Prigge, Molly B. D.; Alexander, Andrew L.; Lainhart, Janet E.

2014-01-01

The present study used an accelerated longitudinal design to examine group differences and age-related changes in processing speed in 81 individuals with Autism Spectrum Disorder (ASD) compared to 56 age-matched individuals with typical development (ages 6–39 years). Processing speed was assessed using the Wechsler Intelligence Scale for Children-3rd edition (WISC-III) and the Wechsler Adult Intelligence Scale-3rd edition (WAIS-III). Follow-up analyses examined processing speed subtest performance and relations between processing speed and white matter microstructure (as measured with diffusion tensor imaging [DTI] in a subset of these participants). After controlling for full scale IQ, the present results show that processing speed index standard scores were on average 12 points lower in the group with ASD compared to the group with typical development. There were, however, no significant group differences in standard score age-related changes within this age range. For subtest raw scores, the group with ASD demonstrated robustly slower processing speeds in the adult versions of the IQ test (i.e., WAIS-III) but not in the child versions (WISC-III), even though age-related changes were similar in both the ASD and typically developing groups. This pattern of results may reflect difficulties that become increasingly evident in ASD on more complex measures of processing speed. Finally, DTI measures of whole-brain white matter microstructure suggested that fractional anisotropy (but not mean diffusivity, radial diffusivity, or axial diffusivity) made significant but small-sized contributions to processing speed standard scores across our entire sample. Taken together, the present findings suggest that robust decreases in processing speed may be present in ASD, more pronounced in adulthood, and partially attributable to white matter microstructural integrity. PMID:24269298

The Effect of a Combined High-Intensity Plyometric and Speed Training Program on the Running and Jumping Ability of Male Handball Players

PubMed Central

Cherif, Monsef; Said, Mohamed; Chaatani, Sana; Nejlaoui, Olfa; Gomri, Daghbaji; Abdallah, Aouidet

2012-01-01

Purpose The aim of this study was to investigate the effect of a combined program including sprint repetitions and drop jump training in the same session on male handball players. Methods Twenty-two male handball players aged more than 20 years were assigned into 2 groups: experimental group (n=11) and control group (n=11). Selection was based on variables “axis” and “lines”, goalkeepers were not included. The experimental group was subjected to 2 testing periods (test and retest) separated by 12 weeks of an additional combined plyometric and running speed training program. The control group performed the usual handball training. The testing period comprised, at the first day, a medical checking, anthropometric measurements and an incremental exercise test called yo-yo intermittent recovery test. 2 days later, participants performed the Repeated Sprint Ability test (RSA), and performed the Jumping Performance using 3 different events: Squat jump (SJ), Countermovement jump without (CMJ) and with arms (CMJA), and Drop jump (DJ). At the end of the training period, participants performed again the repeated sprint ability test, and the jumping performance. Results The conventional combined program improved the explosive force ability of handball players in CMJ (P=0.01), CMJA (P=0.01) and DJR (P=0.03). The change was 2.78, 2.42 and 2.62% respectively. No significant changes were noted in performances of the experimental group at the squat jump test and the drop jump with the left leg test. The training intervention also improved the running speed ability of the experimental group (P=0.003). No statistical differences were observed between lines or axes. Conclusion Additional combined training program between sprint repetition and vertical jump in the same training session positively influence the jumping ability and the sprint ability of handball players. PMID:22461962

The effect of a combined high-intensity plyometric and speed training program on the running and jumping ability of male handball players.

PubMed

Cherif, Monsef; Said, Mohamed; Chaatani, Sana; Nejlaoui, Olfa; Gomri, Daghbaji; Abdallah, Aouidet

2012-03-01

The aim of this study was to investigate the effect of a combined program including sprint repetitions and drop jump training in the same session on male handball players. Twenty-two male handball players aged more than 20 years were assigned into 2 groups: experimental group (n=11) and control group (n=11). Selection was based on variables "axis" and "lines", goalkeepers were not included. The experimental group was subjected to 2 testing periods (test and retest) separated by 12 weeks of an additional combined plyometric and running speed training program. The control group performed the usual handball training. The testing period comprised, at the first day, a medical checking, anthropometric measurements and an incremental exercise test called yo-yo intermittent recovery test. 2 days later, participants performed the Repeated Sprint Ability test (RSA), and performed the Jumping Performance using 3 different events: Squat jump (SJ), Countermovement jump without (CMJ) and with arms (CMJA), and Drop jump (DJ). At the end of the training period, participants performed again the repeated sprint ability test, and the jumping performance. The conventional combined program improved the explosive force ability of handball players in CMJ (P=0.01), CMJA (P=0.01) and DJR (P=0.03). The change was 2.78, 2.42 and 2.62% respectively. No significant changes were noted in performances of the experimental group at the squat jump test and the drop jump with the left leg test. The training intervention also improved the running speed ability of the experimental group (P=0.003). No statistical differences were observed between lines or axes. Additional combined training program between sprint repetition and vertical jump in the same training session positively influence the jumping ability and the sprint ability of handball players.

Enhanced Facial Symmetry Assessment in Orthodontists

PubMed Central

Jackson, Tate H.; Clark, Kait; Mitroff, Stephen R.

2013-01-01

Assessing facial symmetry is an evolutionarily important process, which suggests that individual differences in this ability should exist. As existing data are inconclusive, the current study explored whether a group trained in facial symmetry assessment, orthodontists, possessed enhanced abilities. Symmetry assessment was measured using face and non-face stimuli among orthodontic residents and two control groups: university participants with no symmetry training and airport security luggage screeners, a group previously shown to possess expert visual search skills unrelated to facial symmetry. Orthodontic residents were more accurate at assessing symmetry in both upright and inverted faces compared to both control groups, but not for non-face stimuli. These differences are not likely due to motivational biases or a speed-accuracy tradeoff—orthodontic residents were slower than the university participants but not the security screeners. Understanding such individual differences in facial symmetry assessment may inform the perception of facial attractiveness. PMID:24319342

Long-Term Cognitive Impairment in Kleine-Levin Syndrome

PubMed Central

Uguccioni, Ginevra; Lavault, Sophie; Chaumereuil, Charlotte; Golmard, Jean-Louis; Gagnon, Jean-François; Arnulf, Isabelle

2016-01-01

Study Objectives: In Kleine-Levin syndrome (KLS), episodes of hypersomnia, cognitive, and behavioral disturbances alternate with asymptomatic periods. Because 50% of patients report decreased academic performances, we evaluated their cognitive status during asymptomatic periods, determinants of deficits, and changes during follow-up. Methods: The cognitive assessment during asymptomatic periods in all consecutive patients with typical KLS and healthy controls included the non-verbal intelligence quotient (Raven Progressive Matrices), the Trail Making Test, the Stroop Color-Word Test, the Wechsler Memory Test, verbal fluencies, the Free and Cued Learning Memory Test, and the Rey-Osterreith Complex Figure. Cognitive status was reevaluated after 0.5 to 2 y in 44 patients. Results: At baseline, compared with the 42 controls, the 122 patients with KLS exhibited lower non-verbal intelligence quotient, speed of processing, attention, and reduced retrieval strategies in episodic memory. Higher episode frequency, shorter episode duration, shorter time since last episode, deeper sleep, and megaphagia during episodes predicted impaired memory. The visuoconstructional abilities and non-verbal memory were intact. After a mean follow-up of 1.7 ± 1.0 y, the episode frequency decreased from 4.6 ± 4.8 to 1.7 ± 1.9/y. The logical reasoning and attention improved, the processing speed remained low, and the retrieval strategies in verbal memory further worsened. Conclusions: In this field study, one-third of patients with KLS have long-term cognitive deficits affecting retrieval and processing speed. Cognitive function should be systematically tested in patients with KLS, which appears important to help patients in their academic studies. Citation: Uguccioni G, Lavault S, Chaumereuil C, Golmard JL, Gagnon JF, Arnulf I. Long-term cognitive impairment in kleine-levin syndrome. SLEEP 2016;39(2):429–438. PMID:26414895

A quantitative meta-analysis of neurocognitive functioning in posttraumatic stress disorder

PubMed Central

Scott, J. Cobb; Matt, Georg E.; Wrocklage, Kristen M.; Crnich, Cassandra; Jordan, Jessica; Southwick, Steven M.; Krystal, John H.; Schweinsburg, Brian C.

2014-01-01

Posttraumatic stress disorder (PTSD) is associated with regional alterations in brain structure and function that are hypothesized to contribute to symptoms and cognitive deficits associated with the disorder. We present here the first systematic meta-analysis of neurocognitive outcomes associated with PTSD to examine a broad range of cognitive domains and describe the profile of cognitive deficits, as well as modifying clinical factors and study characteristics. This report is based on data from 60 studies totaling 4,108 participants, including 1,779with PTSD, 1,446 trauma-exposed comparison participants, and 895 healthy comparison participants without trauma exposure. Effect size estimates were calculated using a mixed-effects meta-analysis for nine cognitive domains: attention/working memory, executive functions, verbal learning, verbal memory, visual learning, visual memory, language, speed of information processing, and visuospatial abilities. Analyses revealed significant neurocognitive effects associated with PTSD, although these ranged widely in magnitude, with the largest effect sizes in verbal learning (d =−.62), speed of information processing (d =−.59), attention/working memory (d =−.50), and verbal memory (d =−.46). Effect size estimates were significantly larger in treatment-seeking than community samples and in studies that did not exclude participants with attention-deficit hyperactivity disorder, and effect sizes were affected by between-group IQ discrepancies and the gender composition of the PTSD groups. Our findings indicate that consideration of neuropsychological functioning in attention, verbal memory, and speed of information processing may have important implications for the effective clinical management of persons with PTSD. Results are further discussed in the context of cognitive models of PTSD and the limitations of this literature. PMID:25365762

Processing speed, executive function, and academic achievement in children with dextro-transposition of the great arteries: Testing a longitudinal developmental cascade model

PubMed Central

Cassidy, Adam R.; White, Matthew T.; DeMaso, David R.; Newburger, Jane W.; Bellinger, David C.

2016-01-01

Objective To establish executive function (EF) structure/organization and test a longitudinal developmental cascade model linking processing speed (PS) and EF skills at 8-years of age to academic achievement outcomes, both at 8- and 16-years, in a large sample of children/adolescents with surgically-repaired dextro-transposition of the great arteries (d-TGA). Method Data for this study come from the 8-(n = 155) and 16-year (n = 139) time points of the Boston Circulatory Arrest Study and included WISC-III, Trail Making Test, Test of Variables of Attention, and WIAT/WIAT-II tasks. Results A 2-factor model (Working Memory/Inhibition and Shifting) provided the best fit for the EF data, χ2(3) = 1.581, p = .66, RMSEA = 0, CFI = 1, NNFI = 1.044). Working Memory/Inhibition and Shifting factors were not correlated. In the structural equation model, PS was directly related to both EF factors and Reading at 8 years, and was indirectly related to Math and Reading achievement, both concurrently and longitudinally, via its effects on Working Memory/Inhibition. Shifting at 8 years was significantly associated with Math (but not Reading) at 16 years. Conclusions The academic difficulties experienced by children and adolescents with d-TGA may be driven, at least in part, by underlying deficits in processing speed and aspects of executive function. Intervention efforts aimed at bolstering these abilities, particularly if implemented early in development, may prove beneficial in improving academic outcomes and, perhaps by extension, in reducing the stress and diminished self-confidence often associated with academic underachievement. PMID:27077787

Reaction time, processing speed and sustained attention in schizophrenia: impact on social functioning.

PubMed

Lahera, Guillermo; Ruiz, Alicia; Brañas, Antía; Vicens, María; Orozco, Arantxa

Previous studies have linked processing speed with social cognition and functioning of patients with schizophrenia. A discriminant analysis is needed to determine the different components of this neuropsychological construct. This paper analyzes the impact of processing speed, reaction time and sustained attention on social functioning. 98 outpatients between 18 and 65 with DSM-5 diagnosis of schizophrenia, with a period of 3 months of clinical stability, were recruited. Sociodemographic and clinical data were collected, and the following variables were measured: processing speed (Trail Making Test [TMT], symbol coding [BACS], verbal fluency), simple and elective reaction time, sustained attention, recognition of facial emotions and global functioning. Processing speed (measured only through the BACS), sustained attention (CPT) and elective reaction time (but not simple) were associated with functioning. Recognizing facial emotions (FEIT) correlated significantly with scores on measures of processing speed (BACS, Animals, TMT), sustained attention (CPT) and reaction time. The linear regression model showed a significant relationship between functioning, emotion recognition (P=.015) and processing speed (P=.029). A deficit in processing speed and facial emotion recognition are associated with worse global functioning in patients with schizophrenia. Copyright © 2017 SEP y SEPB. Publicado por Elsevier España, S.L.U. All rights reserved.

Person-Fit Statistics for Joint Models for Accuracy and Speed

ERIC Educational Resources Information Center

Fox, Jean-Paul; Marianti, Sukaesi

2017-01-01

Response accuracy and response time data can be analyzed with a joint model to measure ability and speed of working, while accounting for relationships between item and person characteristics. In this study, person-fit statistics are proposed for joint models to detect aberrant response accuracy and/or response time patterns. The person-fit tests…

Holographic memory using beam steering

NASA Technical Reports Server (NTRS)

Chao, Tien-Hsin (Inventor); Hanan, Jay C. (Inventor); Reyes, George F. (Inventor); Zhou, Hanying (Inventor)

2007-01-01

A method, apparatus, and system provide the ability for storing holograms at high speed. A single laser diode emits a collimated laser beam to both write to and read from a photorefractice crystal. One or more liquid crystal beam steering spatial light modulators (BSSLMs) steer a reference beam, split from the collimated laser beam, at high speed to the photorefractive crystal.

European birds adjust their flight initiation distance to road speed limits.

PubMed

Legagneux, Pierre; Ducatez, Simon

2013-10-23

Behavioural responses can help species persist in habitats modified by humans. Roads and traffic greatly affect animals' mortality not only through habitat structure modifications but also through direct mortality owing to collisions. Although species are known to differ in their sensitivity to the risk of collision, whether individuals can change their behaviour in response to this is still unknown. Here, we tested whether common European birds changed their flight initiation distances (FIDs) in response to vehicles according to road speed limit (a known factor affecting killing rates on roads) and vehicle speed. We found that FID increased with speed limit, although vehicle speed had no effect. This suggests that birds adjust their flight distance to speed limit, which may reduce collision risks and decrease mortality maximizing the time allocated to foraging behaviours. Mobility and territory size are likely to affect an individuals' ability to respond adaptively to local speed limits.

THRUST BEARING

DOEpatents

Heller, P.R.

1958-09-16

A thrust bearing suitable for use with a rotor or blower that is to rotate about a vertical axis is descrihed. A centrifagal jack is provided so thnt the device may opernte on one hearing at starting and lower speeds, and transfer the load to another bearing at higher speeds. A low viscosity fluid is used to lubricate the higher speed operation bearing, in connection with broad hearing -surfaces, the ability to withstand great loads, and a relatively high friction loss, as contraated to the lower speed operatio;n bearing which will withstand only light thrust loads but is sufficiently frictionfree to avoid bearing seizure during slow speed or startup operation. An axially aligned shaft pin provides the bearing surface for low rotational speeds, but at higher speed, weights operating against spring tension withdraw nthe shaft pin into the bearing proper and the rotor shaft comes in contact with the large bearing surfaces.