Contribution of rare inherited and de novo variants in 2,871 congenital heart disease probands

PubMed Central

Jin, Sheng Chih; Homsy, Jason; Zaidi, Samir; Lu, Qiongshi; Morton, Sarah; DePalma, Steven R.; Zeng, Xue; Qi, Hongjian; Chang, Weni; Sierant, Michael C.; Hung, Wei-Chien; Haider, Shozeb; Zhang, Junhui; Knight, James; Bjornson, Robert D.; Castaldi, Christopher; Tikhonoa, Irina R.; Bilguvar, Kaya; Mane, Shrikant M.; Sanders, Stephan J.; Mital, Seema; Russell, Mark; Gaynor, William; Deanfield, John; Giardini, Alessandro; Porter, George A.; Srivastava, Deepak; Lo, Cecelia W.; Shen, Yufeng; Watkins, W. Scott; Yandell, Mark; Yost, H. Joseph; Tristani-Firouzi, Martin; Newburger, Jane W.; Roberts, Amy E.; Kim, Richard; Zhao, Hongyu; Kaltman, Jonathan R.; Goldmuntz, Elizabeth; Chung, Wendy K.; Seidman, Jonathan G.; Gelb, Bruce D.; Seidman, Christine E.; Lifton, Richard P.; Brueckner, Martina

2017-01-01

Congenital heart disease (CHD) is the leading cause of mortality from birth defects. Exome sequencing of a single cohort of 2,871 CHD probands including 2,645 parent-offspring trios implicated rare inherited mutations in 1.8%, including a recessive founder mutation in GDF1 accounting for ~5% of severe CHD in Ashkenazim, recessive genotypes in MYH6 accounting for ~11% of Shone complex, and dominant FLT4 mutations accounting for 2.3% of Tetralogy of Fallot. De novo mutations (DNMs) accounted for 8% of cases, including ~3% of isolated CHD patients and ~28% with both neurodevelopmental and extra-cardiac congenital anomalies. Seven genes surpassed thresholds for genome-wide significance and 12 genes not previously implicated in CHD had > 70% probability of being disease-related; DNMs in ~440 genes are inferred to contribute to CHD. There was striking overlap between genes with damaging DNMs in probands with CHD and autism. PMID:28991257

New observations on maternal age effect on germline de novo mutations.

PubMed

Wong, Wendy S W; Solomon, Benjamin D; Bodian, Dale L; Kothiyal, Prachi; Eley, Greg; Huddleston, Kathi C; Baker, Robin; Thach, Dzung C; Iyer, Ramaswamy K; Vockley, Joseph G; Niederhuber, John E

2016-01-19

Germline mutations are the source of evolution and contribute substantially to many health-related processes. Here we use whole-genome deep sequencing data from 693 parents-offspring trios to examine the de novo point mutations (DNMs) in the offspring. Our estimate for the mutation rate per base pair per generation is 1.05 × 10(-8), well within the range of previous studies. We show that maternal age has a small but significant correlation with the total number of DNMs in the offspring after controlling for paternal age (0.51 additional mutations per year, 95% CI: 0.29, 0.73), which was not detectable in the smaller and younger parental cohorts of earlier studies. Furthermore, while the total number of DNMs increases at a constant rate for paternal age, the contribution from the mother increases at an accelerated rate with age.These observations have implications related to the incidence of de novo mutations relating to maternal age.

Contribution of rare inherited and de novo variants in 2,871 congenital heart disease probands.

PubMed

Jin, Sheng Chih; Homsy, Jason; Zaidi, Samir; Lu, Qiongshi; Morton, Sarah; DePalma, Steven R; Zeng, Xue; Qi, Hongjian; Chang, Weni; Sierant, Michael C; Hung, Wei-Chien; Haider, Shozeb; Zhang, Junhui; Knight, James; Bjornson, Robert D; Castaldi, Christopher; Tikhonoa, Irina R; Bilguvar, Kaya; Mane, Shrikant M; Sanders, Stephan J; Mital, Seema; Russell, Mark W; Gaynor, J William; Deanfield, John; Giardini, Alessandro; Porter, George A; Srivastava, Deepak; Lo, Cecelia W; Shen, Yufeng; Watkins, W Scott; Yandell, Mark; Yost, H Joseph; Tristani-Firouzi, Martin; Newburger, Jane W; Roberts, Amy E; Kim, Richard; Zhao, Hongyu; Kaltman, Jonathan R; Goldmuntz, Elizabeth; Chung, Wendy K; Seidman, Jonathan G; Gelb, Bruce D; Seidman, Christine E; Lifton, Richard P; Brueckner, Martina

2017-11-01

Congenital heart disease (CHD) is the leading cause of mortality from birth defects. Here, exome sequencing of a single cohort of 2,871 CHD probands, including 2,645 parent-offspring trios, implicated rare inherited mutations in 1.8%, including a recessive founder mutation in GDF1 accounting for ∼5% of severe CHD in Ashkenazim, recessive genotypes in MYH6 accounting for ∼11% of Shone complex, and dominant FLT4 mutations accounting for 2.3% of Tetralogy of Fallot. De novo mutations (DNMs) accounted for 8% of cases, including ∼3% of isolated CHD patients and ∼28% with both neurodevelopmental and extra-cardiac congenital anomalies. Seven genes surpassed thresholds for genome-wide significance, and 12 genes not previously implicated in CHD had >70% probability of being disease related. DNMs in ∼440 genes were inferred to contribute to CHD. Striking overlap between genes with damaging DNMs in probands with CHD and autism was also found.

Whole-genome sequencing of monozygotic twins discordant for schizophrenia indicates multiple genetic risk factors for schizophrenia.

PubMed

Tang, Jinsong; Fan, Yu; Li, Hong; Xiang, Qun; Zhang, Deng-Feng; Li, Zongchang; He, Ying; Liao, Yanhui; Wang, Ya; He, Fan; Zhang, Fengyu; Shugart, Yin Yao; Liu, Chunyu; Tang, Yanqing; Chan, Raymond C K; Wang, Chuan-Yue; Yao, Yong-Gang; Chen, Xiaogang

2017-06-20

Schizophrenia is a common disorder with a high heritability, but its genetic architecture is still elusive. We implemented whole-genome sequencing (WGS) analysis of 8 families with monozygotic (MZ) twin pairs discordant for schizophrenia to assess potential association of de novo mutations (DNMs) or inherited variants with susceptibility to schizophrenia. Eight non-synonymous DNMs (including one splicing site) were identified and shared by twins, which were either located in previously reported schizophrenia risk genes (p.V24689I mutation in TTN, p.S2506T mutation in GCN1L1, IVS3+1G > T in DOCK1) or had a benign to damaging effect according to in silico prediction analysis. By searching the inherited rare damaging or loss-of-function (LOF) variants and common susceptible alleles from three classes of schizophrenia candidate genes, we were able to distill genetic alterations in several schizophrenia risk genes, including GAD1, PLXNA2, RELN and FEZ1. Four inherited copy number variations (CNVs; including a large deletion at 16p13.11) implicated for schizophrenia were identified in four families, respectively. Most of families carried both missense DNMs and inherited risk variants, which might suggest that DNMs, inherited rare damaging variants and common risk alleles together conferred to schizophrenia susceptibility. Our results support that schizophrenia is caused by a combination of multiple genetic factors, with each DNM/variant showing a relatively small effect size. Copyright © 2017 Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, and Genetics Society of China. All rights reserved.

Diseases Neglected by the Media in Espírito Santo, Brazil in 2011-2012.

PubMed

Cavaca, Aline Guio; Emerich, Tatiana Breder; Vasconcellos-Silva, Paulo Roberto; dos Santos-Neto, Edson Theodoro; Oliveira, Adauto Emmerich

2016-04-01

The aims of the present study were to identify and analyse the Diseases Neglected by the Media (DNMs) via a comparison between the most important health issues to the population of Espírito Santo, Brazil, from the epidemiological perspective (health value) and their effective coverage by the print media, and to analyse the DNMs considering the perspective of key journalists involved in the dissemination of health topics in the state media. Morbidity and mortality data were collected from official documents and from Health Information Systems. In parallel, the diseases reported in the two major newspapers of Espírito Santo in 2011-2012 were identified from 10,771 news articles. Concomitantly, eight interviews were conducted with reporters from the two newspapers to understand the journalists' reasons for the coverage or neglect of certain health/disease topics. Quantitatively, the DNMs identified diseases associated with poverty, including tuberculosis, leprosy, schistosomiasis, leishmaniasis, and trachoma. Apart from these, diseases with outbreaks in the period evaluated, including whooping cough and meningitis, some cancers, respiratory diseases, ischaemic heart disease, and stroke, were also seldom addressed by the media. In contrast, dengue fever, acquired immune deficiency syndrome (AIDS), diabetes, breast cancer, prostate cancer, tracheal cancer, and bronchial and lung cancers were broadly covered in the period analysed, corroborating the tradition of media disclosure of these diseases. Qualitatively, the DNMs included rare diseases, such as amyotrophic lateral sclerosis (ALS), leishmaniasis, Down syndrome, and verminoses. The reasons for the neglect of these topics by the media included the political and economic interests of the newspapers, their editorial line, and the organizational routine of the newsrooms. Media visibility acts as a strategy for legitimising priorities and contextualizing various realities. Therefore, we propose that the health problems identified should enter the public agenda and begin to be recognized as legitimate demands.

Diseases Neglected by the Media in Espírito Santo, Brazil in 2011–2012

PubMed Central

Vasconcellos-Silva, Paulo Roberto; Oliveira, Adauto Emmerich

2016-01-01

Background The aims of the present study were to identify and analyse the Diseases Neglected by the Media (DNMs) via a comparison between the most important health issues to the population of Espírito Santo, Brazil, from the epidemiological perspective (health value) and their effective coverage by the print media, and to analyse the DNMs considering the perspective of key journalists involved in the dissemination of health topics in the state media. Methodology Morbidity and mortality data were collected from official documents and from Health Information Systems. In parallel, the diseases reported in the two major newspapers of Espírito Santo in 2011–2012 were identified from 10,771 news articles. Concomitantly, eight interviews were conducted with reporters from the two newspapers to understand the journalists’ reasons for the coverage or neglect of certain health/disease topics. Principal Findings Quantitatively, the DNMs identified diseases associated with poverty, including tuberculosis, leprosy, schistosomiasis, leishmaniasis, and trachoma. Apart from these, diseases with outbreaks in the period evaluated, including whooping cough and meningitis, some cancers, respiratory diseases, ischaemic heart disease, and stroke, were also seldom addressed by the media. In contrast, dengue fever, acquired immune deficiency syndrome (AIDS), diabetes, breast cancer, prostate cancer, tracheal cancer, and bronchial and lung cancers were broadly covered in the period analysed, corroborating the tradition of media disclosure of these diseases. Qualitatively, the DNMs included rare diseases, such as amyotrophic lateral sclerosis (ALS), leishmaniasis, Down syndrome, and verminoses. The reasons for the neglect of these topics by the media included the political and economic interests of the newspapers, their editorial line, and the organizational routine of the newsrooms. Conclusions Media visibility acts as a strategy for legitimising priorities and contextualizing various realities. Therefore, we propose that the health problems identified should enter the public agenda and begin to be recognized as legitimate demands. PMID:27115486

Convergent roles of de novo mutations and common variants in schizophrenia in tissue-specific and spatiotemporal co-expression network.

PubMed

Jia, Peilin; Chen, Xiangning; Fanous, Ayman H; Zhao, Zhongming

2018-05-24

Genetic components susceptible to complex disease such as schizophrenia include a wide spectrum of variants, including common variants (CVs) and de novo mutations (DNMs). Although CVs and DNMs differ by origin, it remains elusive whether and how they interact at the gene, pathway, and network levels that leads to the disease. In this work, we characterized the genes harboring schizophrenia-associated CVs (CVgenes) and the genes harboring DNMs (DNMgenes) using measures from network, tissue-specific expression profile, and spatiotemporal brain expression profile. We developed an algorithm to link the DNMgenes and CVgenes in spatiotemporal brain co-expression networks. DNMgenes tended to have central roles in the human protein-protein interaction (PPI) network, evidenced in their high degree and high betweenness values. DNMgenes and CVgenes connected with each other significantly more often than with other genes in the networks. However, only CVgenes remained significantly connected after adjusting for their degree. In our gene co-expression PPI network, we found DNMgenes and CVgenes connected in a tissue-specific fashion, and such a pattern was similar to that in GTEx brain but not in other GTEx tissues. Importantly, DNMgene-CVgene subnetworks were enriched with pathways of chromatin remodeling, MHC protein complex binding, and neurotransmitter activities. In summary, our results unveiled that both DNMgenes and CVgenes contributed to a core set of biologically important pathways and networks, and their interactions may attribute to the risk for schizophrenia. Our results also suggested a stronger biological effect of DNMgenes than CVgenes in schizophrenia.

A cortical neural prosthesis for restoring and enhancing memory

NASA Astrophysics Data System (ADS)

Berger, Theodore W.; Hampson, Robert E.; Song, Dong; Goonawardena, Anushka; Marmarelis, Vasilis Z.; Deadwyler, Sam A.

2011-08-01

A primary objective in developing a neural prosthesis is to replace neural circuitry in the brain that no longer functions appropriately. Such a goal requires artificial reconstruction of neuron-to-neuron connections in a way that can be recognized by the remaining normal circuitry, and that promotes appropriate interaction. In this study, the application of a specially designed neural prosthesis using a multi-input/multi-output (MIMO) nonlinear model is demonstrated by using trains of electrical stimulation pulses to substitute for MIMO model derived ensemble firing patterns. Ensembles of CA3 and CA1 hippocampal neurons, recorded from rats performing a delayed-nonmatch-to-sample (DNMS) memory task, exhibited successful encoding of trial-specific sample lever information in the form of different spatiotemporal firing patterns. MIMO patterns, identified online and in real-time, were employed within a closed-loop behavioral paradigm. Results showed that the model was able to predict successful performance on the same trial. Also, MIMO model-derived patterns, delivered as electrical stimulation to the same electrodes, improved performance under normal testing conditions and, more importantly, were capable of recovering performance when delivered to animals with ensemble hippocampal activity compromised by pharmacologic blockade of synaptic transmission. These integrated experimental-modeling studies show for the first time that, with sufficient information about the neural coding of memories, a neural prosthesis capable of real-time diagnosis and manipulation of the encoding process can restore and even enhance cognitive, mnemonic processes.

Extensive Variation in the Mutation Rate Between and Within Human Genes Associated with Mendelian Disease.

PubMed

Smith, Thomas; Ho, Gladys; Christodoulou, John; Price, Elizabeth Ann; Onadim, Zerrin; Gauthier-Villars, Marion; Dehainault, Catherine; Houdayer, Claude; Parfait, Beatrice; van Minkelen, Rick; Lohman, Dietmar; Eyre-Walker, Adam

2016-05-01

We have investigated whether the mutation rate varies between genes and sites using de novo mutations (DNMs) from three genes associated with Mendelian diseases (RB1, NF1, and MECP2). We show that the relative frequency of mutations at CpG dinucleotides relative to non-CpG sites varies between genes and relative to the genomic average. In particular we show that the rate of transition mutation at CpG sites relative to the rate of non-CpG transversion is substantially higher in our disease genes than amongst DNMs in general; the rate of CpG transition can be several hundred-fold greater than the rate of non-CpG transversion. We also show that the mutation rate varies significantly between sites of a particular mutational type, such as non-CpG transversion, within a gene. We estimate that for all categories of sites, except CpG transitions, there is at least a 30-fold difference in the mutation rate between the 10% of sites with the highest and lowest mutation rates. However, our best estimate is that the mutation rate varies by several hundred-fold variation. We suggest that the presence of hypermutable sites may be one reason certain genes are associated with disease. © 2016 WILEY PERIODICALS, INC.

Monkey pulvinar neurons fire differentially to snake postures.

PubMed

Le, Quan Van; Isbell, Lynne A; Matsumoto, Jumpei; Le, Van Quang; Hori, Etsuro; Tran, Anh Hai; Maior, Rafael S; Tomaz, Carlos; Ono, Taketoshi; Nishijo, Hisao

2014-01-01

There is growing evidence from both behavioral and neurophysiological approaches that primates are able to rapidly discriminate visually between snakes and innocuous stimuli. Recent behavioral evidence suggests that primates are also able to discriminate the level of threat posed by snakes, by responding more intensely to a snake model poised to strike than to snake models in coiled or sinusoidal postures (Etting and Isbell 2014). In the present study, we examine the potential for an underlying neurological basis for this ability. Previous research indicated that the pulvinar is highly sensitive to snake images. We thus recorded pulvinar neurons in Japanese macaques (Macaca fuscata) while they viewed photos of snakes in striking and non-striking postures in a delayed non-matching to sample (DNMS) task. Of 821 neurons recorded, 78 visually responsive neurons were tested with the all snake images. We found that pulvinar neurons in the medial and dorsolateral pulvinar responded more strongly to snakes in threat displays poised to strike than snakes in non-threat-displaying postures with no significant difference in response latencies. A multidimensional scaling analysis of the 78 visually responsive neurons indicated that threat-displaying and non-threat-displaying snakes were separated into two different clusters in the first epoch of 50 ms after stimulus onset, suggesting bottom-up visual information processing. These results indicate that pulvinar neurons in primates discriminate between poised to strike from those in non-threat-displaying postures. This neuronal ability likely facilitates behavioral discrimination and has clear adaptive value. Our results are thus consistent with the Snake Detection Theory, which posits that snakes were instrumental in the evolution of primate visual systems.

Short-term testosterone manipulations do not affect cognition or motor function but differentially modulate emotions in young and older male rhesus monkeys.

PubMed

Kelly, Brian; Maguire-Herring, Vanessa; Rose, Christian M; Gore, Heather E; Ferrigno, Stephen; Novak, Melinda A; Lacreuse, Agnès

2014-11-01

Human aging is characterized by declines in cognition and fine motor function as well as improved emotional regulation. In men, declining levels of testosterone (T) with age have been implicated in the development of these age-related changes. However, studies examining the effects of T replacement on cognition, emotion and fine motor function in older men have not provided consistent results. Rhesus monkeys (Macaca mulatta) are excellent models for human cognitive aging and may provide novel insights on this issue. We tested 10 aged intact male rhesus monkeys (mean age=19, range 15-25) on a battery of cognitive, motor and emotional tasks at baseline and under low or high T experimental conditions. Their performance was compared to that of 6 young males previously tested in the same paradigm (Lacreuse et al., 2009; Lacreuse et al., 2010). Following a 4-week baseline testing period, monkeys were treated with a gonadotropin releasing hormone agonist (Depot Lupron, 200 μg/kg) to suppress endogenous T and were tested on the task battery under a 4-week high T condition (injection of Lupron+T enanthate, 20 mg/kg, n=8) or 4-week low T condition (injection of Lupron+oil vehicle, n=8) before crossing over to the opposite treatment. The cognitive tasks consisted of the Delayed Non-Matching-to-Sample (DNMS), the Delayed Response (DR), and the Delayed Recognition Span Test (spatial-DRST). The emotional tasks included an object Approach-Avoidance task and a task in which monkeys were played videos of unfamiliar conspecifics in different emotional context (Social Playbacks). The fine motor task was the Lifesaver task that required monkeys to remove a Lifesaver candy from rods of different complexity. T manipulations did not significantly affect visual recognition memory, working memory, reference memory or fine motor function at any age. In the Approach-Avoidance task, older monkeys, but not younger monkeys, spent more time in proximity of novel objects in the high T condition relative to the low T condition. In both age groups, high T increased watching time of threatening social stimuli in the Social Playbacks. These results suggest that T affects some aspects of emotional processing but has no effect on fine motor function or cognition in young or older male macaques. It is possible that the duration of T treatment was not long enough to affect cognition or fine motor function or that T levels were too high to improve these outcomes. An alternative explanation for the discrepancies of our findings with some of the cognitive and emotional effects of T reported in rodents and humans may be the use of a chemical castration, which reduced circulating gonadotropins in addition to T. Further studies will investigate whether the luteinizing hormone LH mediates the effects of T on brain function in male primates. Copyright © 2014 Elsevier Inc. All rights reserved.

Monkey Pulvinar Neurons Fire Differentially to Snake Postures

PubMed Central

Le, Quan Van; Isbell, Lynne A.; Matsumoto, Jumpei; Le, Van Quang; Hori, Etsuro; Tran, Anh Hai; Maior, Rafael S.; Tomaz, Carlos; Ono, Taketoshi; Nishijo, Hisao

2014-01-01

There is growing evidence from both behavioral and neurophysiological approaches that primates are able to rapidly discriminate visually between snakes and innocuous stimuli. Recent behavioral evidence suggests that primates are also able to discriminate the level of threat posed by snakes, by responding more intensely to a snake model poised to strike than to snake models in coiled or sinusoidal postures (Etting and Isbell 2014). In the present study, we examine the potential for an underlying neurological basis for this ability. Previous research indicated that the pulvinar is highly sensitive to snake images. We thus recorded pulvinar neurons in Japanese macaques (Macaca fuscata) while they viewed photos of snakes in striking and non-striking postures in a delayed non-matching to sample (DNMS) task. Of 821 neurons recorded, 78 visually responsive neurons were tested with the all snake images. We found that pulvinar neurons in the medial and dorsolateral pulvinar responded more strongly to snakes in threat displays poised to strike than snakes in non-threat-displaying postures with no significant difference in response latencies. A multidimensional scaling analysis of the 78 visually responsive neurons indicated that threat-displaying and non-threat-displaying snakes were separated into two different clusters in the first epoch of 50 ms after stimulus onset, suggesting bottom-up visual information processing. These results indicate that pulvinar neurons in primates discriminate between poised to strike from those in non-threat-displaying postures. This neuronal ability likely facilitates behavioral discrimination and has clear adaptive value. Our results are thus consistent with the Snake Detection Theory, which posits that snakes were instrumental in the evolution of primate visual systems. PMID:25479158

Waterproof Silicone Coatings of Thermal Insulation and Vaporization Method

NASA Technical Reports Server (NTRS)

Cagliostro, Domenick E. (Inventor)

1999-01-01

Thermal insulation composed of porous ceramic material can be waterproofed by producing a thin silicone film on the surface of the insulation by exposing it to volatile silicone precursors at ambient conditions. When the silicone precursor reactants are multi-functional siloxanes or silanes containing alkenes or alkynes carbon groups higher molecular weight films can be produced. Catalyst are usually required for the silicone precursors to react at room temperature to form the films. The catalyst are particularly useful in the single component system e.g. dimethylethoxysilane (DNMS) to accelerate the reaction and decrease the time to waterproof and protect the insulation. In comparison to other methods, the chemical vapor technique assures better control over the quantity and location of the film being deposited on the ceramic insulation to improve the waterproof coating.

RACE/A: an architectural account of the interactions between learning, task control, and retrieval dynamics.

PubMed

van Maanen, Leendert; van Rijn, Hedderik; Taatgen, Niels

2012-01-01

This article discusses how sequential sampling models can be integrated in a cognitive architecture. The new theory Retrieval by Accumulating Evidence in an Architecture (RACE/A) combines the level of detail typically provided by sequential sampling models with the level of task complexity typically provided by cognitive architectures. We will use RACE/A to model data from two variants of a picture-word interference task in a psychological refractory period design. These models will demonstrate how RACE/A enables interactions between sequential sampling and long-term declarative learning, and between sequential sampling and task control. In a traditional sequential sampling model, the onset of the process within the task is unclear, as is the number of sampling processes. RACE/A provides a theoretical basis for estimating the onset of sequential sampling processes during task execution and allows for easy modeling of multiple sequential sampling processes within a task. Copyright © 2011 Cognitive Science Society, Inc.

Neural efficiency as a function of task demands☆

PubMed Central

Dunst, Beate; Benedek, Mathias; Jauk, Emanuel; Bergner, Sabine; Koschutnig, Karl; Sommer, Markus; Ischebeck, Anja; Spinath, Birgit; Arendasy, Martin; Bühner, Markus; Freudenthaler, Heribert; Neubauer, Aljoscha C.

2014-01-01

The neural efficiency hypothesis describes the phenomenon that brighter individuals show lower brain activation than less bright individuals when working on the same cognitive tasks. The present study investigated whether the brain activation–intelligence relationship still applies when more versus less intelligent individuals perform tasks with a comparable person-specific task difficulty. In an fMRI-study, 58 persons with lower (n = 28) or respectively higher (n = 30) intelligence worked on simple and difficult inductive reasoning tasks having the same person-specific task difficulty. Consequently, less bright individuals received sample-based easy and medium tasks, whereas bright subjects received sample-based medium and difficult tasks. This design also allowed a comparison of lower versus higher intelligent individuals when working on the same tasks (i.e. sample-based medium task difficulty). In line with expectations, differences in task performance and in brain activation were only found for the subset of tasks with the same sample-based task difficulty, but not when comparing tasks with the same person-specific task difficulty. These results suggest that neural efficiency reflects an (ability-dependent) adaption of brain activation to the respective task demands. PMID:24489416

Combined analysis of job and task benzene air exposures among workers at four US refinery operations

PubMed Central

Shin, Jennifer (Mi); Unice, Ken M; Gaffney, Shannon H; Kreider, Marisa L; Gelatt, Richard H; Panko, Julie M

2016-01-01

Workplace air samples analyzed for benzene at four US refineries from 1976 to 2007 were pooled into a single dataset to characterize similarities and differences between job titles, tasks and refineries, and to provide a robust dataset for exposure reconstruction. Approximately 12,000 non-task (>180 min) personal samples associated with 50 job titles and 4000 task (<180 min) samples characterizing 24 tasks were evaluated. Personal air sample data from four individual refineries were pooled based on a number of factors including (1) the consistent sampling approach used by refinery industrial hygienists over time, (2) the use of similar exposure controls, (3) the comparability of benzene content of process streams and end products, (4) the ability to assign uniform job titles and task codes across all four refineries, and (5) our analysis of variance (ANOVA) of the distribution of benzene air concentrations for select jobs/tasks across all four refineries. The jobs and tasks most frequently sampled included those with highest potential contact with refinery product streams containing benzene, which reflected the targeted sampling approach utilized by the facility industrial hygienists. Task and non-task data were analyzed to identify and account for significant differences within job-area, task-job, and task-area categories. This analysis demonstrated that in general, areas with benzene containing process streams were associated with greater benzene air concentrations compared to areas with process streams containing little to no benzene. For several job titles and tasks analyzed, there was a statistically significant decrease in benzene air concentration after 1990. This study provides a job and task-focused analysis of occupational exposure to benzene during refinery operations, and it should be useful for reconstructing refinery workers’ exposures to benzene over the past 30 years. PMID:26862134

Combined analysis of job and task benzene air exposures among workers at four US refinery operations.

PubMed

Burns, Amanda; Shin, Jennifer Mi; Unice, Ken M; Gaffney, Shannon H; Kreider, Marisa L; Gelatt, Richard H; Panko, Julie M

2017-03-01

Workplace air samples analyzed for benzene at four US refineries from 1976 to 2007 were pooled into a single dataset to characterize similarities and differences between job titles, tasks and refineries, and to provide a robust dataset for exposure reconstruction. Approximately 12,000 non-task (>180 min) personal samples associated with 50 job titles and 4000 task (<180 min) samples characterizing 24 tasks were evaluated. Personal air sample data from four individual refineries were pooled based on a number of factors including (1) the consistent sampling approach used by refinery industrial hygienists over time, (2) the use of similar exposure controls, (3) the comparability of benzene content of process streams and end products, (4) the ability to assign uniform job titles and task codes across all four refineries, and (5) our analysis of variance (ANOVA) of the distribution of benzene air concentrations for select jobs/tasks across all four refineries. The jobs and tasks most frequently sampled included those with highest potential contact with refinery product streams containing benzene, which reflected the targeted sampling approach utilized by the facility industrial hygienists. Task and non-task data were analyzed to identify and account for significant differences within job-area, task-job, and task-area categories. This analysis demonstrated that in general, areas with benzene containing process streams were associated with greater benzene air concentrations compared to areas with process streams containing little to no benzene. For several job titles and tasks analyzed, there was a statistically significant decrease in benzene air concentration after 1990. This study provides a job and task-focused analysis of occupational exposure to benzene during refinery operations, and it should be useful for reconstructing refinery workers' exposures to benzene over the past 30 years.

Task-Dependent Behavioral Dynamics Make the Case for Temporal Integration in Multiple Strategies during Odor Processing

PubMed Central

Brown, Austin; Mehta, Nisarg; Vujovic, Mark; Amina, Tasneem; Fixsen, Bethany

2017-01-01

Differing results in olfactory-based decision-making research regarding the amount of time that rats and mice use to identify odors have led to some disagreements about odor-processing mechanics, including whether or not rodents use temporal integration (i.e., sniffing longer to identify odors better). Reported differences in behavioral strategies may be due to the different types of tasks used in different laboratories. Some researchers have reported that animals performing two-alternative choice (TAC) tasks need only 1–2 sniffs and do not increase performance with longer sampling. Others have reported that animals performing go/no-go (GNG) tasks increase sampling times and performance for difficult discriminations, arguing for temporal integration. We present results from four experiments comparing GNG and TAC tasks over several behavioral variables (e.g., performance, sampling duration). When rats know only one task, they perform better in GNG than in TAC. However, performance was not statistically different when rats learned and were tested in both tasks. Rats sample odors longer in GNG than in TAC, even when they know both tasks and perform them in the same or different sessions. Longer sampling is associated with better performance for both tasks in difficult discriminations, which supports the case for temporal integration over ≥2–6 sniffs in both tasks. These results illustrate that generalizations from a single task about behavioral or cognitive abilities (e.g., processing, perception) do not capture the full range of complexity and can significantly impact inferences about general abilities in sensory perception. SIGNIFICANCE STATEMENT Behavioral tasks and training and testing history affect measured outcomes in cognitive tests. Rats sample odors longer in a go/no-go (GNG) than in a two-alternative choice (TAC) task, performing better in GNG unless they know both tasks. Odor-sampling time is extended in both tasks when the odors to be discriminated are very similar. Rats may extend sampling time to integrate odor information up to ∼0.5 s (2–6 sniffs). Such factors as task, task parameters, and training history affect decision times and performance, making it important to use multiple tasks when making inferences about sensory or cognitive processing. PMID:28336570

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

Buchholz, Bruce A.

The project has two main goals: 1) Identify the types of adducts naphthalene (NA) forms with DNA and 2) determine whether adduct formation correlates with site selective tumor formation in defined subcompartments of the respiratory tract (respiratory and olfactory nasal epithelium and airways of mice, rats and rhesus monkeys). Five tasks are associated with the completion of the goals. Task 1: Contracting and Animal Use Approvals. IACUC and ACURO approvals are complete, The subcontract with UC Davis (UCD) was executed in December 2014. Task 2: Perform In Vitro Study for Goal 1. Rat samples exposed and in freezer while adductmore » standards are being made. Mouse samples need to be exposed in next quarter. Task 3: Perform In Vitro Study for Goal 2. Mouse ex vivo samples completed. Rat and monkey samples need to be completed in the next quarter. Task 4: Sample Preparation and Analysis. Mouse Goal 2 samples completed. Other samples remain to be done. Task 5: Data Interpretation and Reporting. Need rat data to write paper on adduct formation.« less

Airborne concentrations of benzene for dock workers at the ExxonMobil refinery and chemical plant, Baton Rouge, Louisiana, USA (1977-2005).

PubMed

Widner, Thomas E; Gaffney, Shannon H; Panko, Julie M; Unice, Kenneth M; Burns, Amanda M; Kreider, Marisa; Marshall, J Ralph; Booher, Lindsay E; Gelat, Richard H; Paustenbach, Dennis J

2011-03-01

Benzene is a natural constituent of crude oil and natural gas (0.1-3.0% by volume). Materials that are refined from crude oil and natural gas contain some residual benzene. Few datasets have appeared in the peer-reviewed literature characterizing exposures to benzene at specific refineries or during specific tasks. In this study, historical samples of airborne benzene collected from 1977-2005 at the ExxonMobil Baton Rouge, Louisiana, USA, docks were evaluated. Workers were categorized into 11 job titles, and both non-task (≤180 min sample duration) and task-related (<180 min) benzene concentrations were assessed. Approximately 800 personal air samples (406 non-task and 397 task-related) were analyzed. Non-task samples showed that concentrations varied significantly across job titles and generally resulted from exposures during short-duration tasks such as tank sampling. The contractor - tankerman job title had the highest average concentration [N=38, mean 1.4 parts per million (ppm), standard deviation (SD) 2.6]. Task-related samples indicated that the highest exposures were associated with the disconnection of cargo loading hoses (N=134, mean 11 ppm, SD 32). Non-task samples for specific job categories showed that concentrations have decreased over the past 30 years. Recognizing the potential for benzene exposure, this facility has required workers to use respiratory protective equipment during selected tasks and activities; thus, the concentrations measured were likely greater than those that the employee actually experienced. This study provides a job title- and task-focused analysis of occupational exposure to benzene during dock facility operations that is insightful for understanding the Baton Rouge facility and others similar to it over the past 30 years.

Theory of choice in bandit, information sampling and foraging tasks.

PubMed

Averbeck, Bruno B

2015-03-01

Decision making has been studied with a wide array of tasks. Here we examine the theoretical structure of bandit, information sampling and foraging tasks. These tasks move beyond tasks where the choice in the current trial does not affect future expected rewards. We have modeled these tasks using Markov decision processes (MDPs). MDPs provide a general framework for modeling tasks in which decisions affect the information on which future choices will be made. Under the assumption that agents are maximizing expected rewards, MDPs provide normative solutions. We find that all three classes of tasks pose choices among actions which trade-off immediate and future expected rewards. The tasks drive these trade-offs in unique ways, however. For bandit and information sampling tasks, increasing uncertainty or the time horizon shifts value to actions that pay-off in the future. Correspondingly, decreasing uncertainty increases the relative value of actions that pay-off immediately. For foraging tasks the time-horizon plays the dominant role, as choices do not affect future uncertainty in these tasks.

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

Buchholz, B. A.

The project has two main goals: 1) Identify the types of adducts naphthalene (NA) forms with DNA and 2) determine whether adduct formation correlates with site selective tumor formation in defined subcompartments of the respiratory tract (respiratory and olfactory nasal epithelium and airways of mice, rats and rhesus monkeys). Five tasks are associated with the completion of the goals. Task 1: Contracting and Animal Use Approvals. IACUC and ACURO approvals are complete. The subcontract with UC Davis (UCD) was executed in December 2014. Task 2: Perform In Vitro Study for Goal 1. Rat and mouse samples exposures completed. Monkey samplesmore » need to be exposed in next quarter. Task 3: Perform In Vitro Study for Goal 2. Mouse and rat ex vivo exposures completed. Monkey samples need to be completed in the next quarter. Task 4: Sample Preparation and Analysis. Mouse and Rat Goal 2 samples completed. Monkey samples remain to be done for Goal 2. Rat samples completed for Goal 1. Mouse and Monkey samples for Goal 1 need to be completed. Task 5: Data Interpretation and Reporting. Poster will be presented at 2016 Society of Toxicology Meeting. Outline for paper on adduct formation complete and similar to poster for SOT meeting.« less

Occupational exposure to benzene at the ExxonMobil refinery in Baytown, TX (1978-2006).

PubMed

Gaffney, Shannon H; Panko, Julie M; Unice, Ken M; Burns, Amanda M; Kreider, Marisa L; Gelatt, Richard H; Booher, Lindsay E; Paustenbach, Dennis J

2011-01-01

Although occupational benzene exposure of refinery workers has been studied for decades, no extensive analysis of historical industrial hygiene data has been performed focusing on airborne concentrations at specific refineries and tasks. This study characterizes benzene exposures at the ExxonMobil Baytown, TX, refinery from 1978 to 2006 to understand the variability in workers' exposures over time and during different job tasks. Exposures were grouped by operational status, job title, and tasks. More than 9000 industrial hygiene air samples were evaluated; approximately 4000 non-task (> 3 h) and 1000 task-related (< 3 h) personal samples were considered. Each sample was assigned to one of 27 job titles, 29 work areas, and 16 task bins (when applicable). Process technicians were sampled most frequently, resulting in the following mean benzene concentrations by area: hydrofiner (n=245, mean=1.3 p.p.m.), oil movements (n=286, mean=0.23 p.p.m.), reformer (n=575, mean=0.10 p.p.m.), tank farm (n=9, mean=0.65 p.p.m.), waste treatment (n=446, mean=0.13 p.p.m.), and other areas (n=460, mean=0.062 p.p.m.). The most frequently sampled task was sample collection (n=218, mean=0.40 p.p.m.). Job title and area did not significantly impact task-related exposures. Airborne concentrations were significantly lower after 1990 than before 1990. Results of this task-focused study may be useful when analyzing benzene exposures at other refineries.

Neural Correlates of a Default Response in a Delayed Go/No-Go Task

ERIC Educational Resources Information Center

Kalenscher, Tobias; Gunturkun, Onur; Calabrese, Pasquale; Gehlen, Walter; Kalt, Thomas; Diekamp, Bettina

2005-01-01

Working memory, the ability to temporarily retain task-relevant information across a delay, is frequently investigated using delayed matching-to-sample (DMTS) or delayed Go/No-Go tasks (DGNG). In DMTS tasks, sample cues instruct the animal which type of response has to be executed at the end of a delay. Typically, performance decreases with…

Testing Cross-Cultural Generalizability of the Task and Ego Orientation in Sport Questionnaire across American and Chinese Samples

PubMed Central

Monsma, Eva

2016-01-01

This paper examines the factor structure and measurement invariance of the Task and Ego Orientation in Sport Questionnaire (TEOSQ) across American and Chinese samples. Results based on the mean and covariance structure analyses supported configural invariance, metric invariance and scalar invariance across groups. Latent means analyses revealed that American sample had significantly higher mean scores on task and ego orientations than the Chinese sample. The findings suggest that the TEOSQ is a valid and reliable instrument in assessing achievement motivation across these two diverse populations. PMID:27399869

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

Zhang, Fangyan; Zhang, Song; Chung Wong, Pak

Effectively visualizing large graphs and capturing the statistical properties are two challenging tasks. To aid in these two tasks, many sampling approaches for graph simplification have been proposed, falling into three categories: node sampling, edge sampling, and traversal-based sampling. It is still unknown which approach is the best. We evaluate commonly used graph sampling methods through a combined visual and statistical comparison of graphs sampled at various rates. We conduct our evaluation on three graph models: random graphs, small-world graphs, and scale-free graphs. Initial results indicate that the effectiveness of a sampling method is dependent on the graph model, themore » size of the graph, and the desired statistical property. This benchmark study can be used as a guideline in choosing the appropriate method for a particular graph sampling task, and the results presented can be incorporated into graph visualization and analysis tools.« less

Extended Task Space Control for Robotic Manipulators

NASA Technical Reports Server (NTRS)

Backes, Paul G. (Inventor); Long, Mark K. (Inventor)

1996-01-01

The invention is a method of operating a robot in successive sampling intervals to perform a task, the robot having joints and joint actuators with actuator control loops, by decomposing the task into behavior forces, accelerations, velocities and positions of plural behaviors to be exhibited by the robot simultaneously, computing actuator accelerations of the joint actuators for the current sampling interval from both behavior forces, accelerations velocities and positions of the current sampling interval and actuator velocities and positions of the previous sampling interval, computing actuator velocities and positions of the joint actuators for the current sampling interval from the actuator velocities and positions of the previous sampling interval, and, finally, controlling the actuators in accordance with the actuator accelerations, velocities and positions of the current sampling interval. The actuator accelerations, velocities and positions of the current sampling interval are stored for use during the next sampling interval.

Relative versus Absolute Stimulus Control in the Temporal Bisection Task

ERIC Educational Resources Information Center

de Carvalho, Marilia Pinhiero; Machado, Armando

2012-01-01

When subjects learn to associate two sample durations with two comparison keys, do they learn to associate the keys with the short and long samples (relational hypothesis), or with the specific sample durations (absolute hypothesis)? We exposed 16 pigeons to an ABA design in which phases A and B corresponded to tasks using samples of 1 s and 4 s,…

The Relationship between Performance in near Match-to-Sample Tasks and Fluid Intelligence

ERIC Educational Resources Information Center

Frey, Meredith C.

2011-01-01

Match-to-sample is a timed task in which a subject is presented with a visual stimulus (the probe) and must select a match to that stimulus (the target) from among an array of distractors. These tasks are frequently employed as tests of basic cognitive abilities and demonstrate consistent correlations with measures of intelligence. In the current…

Spatial effects, sampling errors, and task specialization in the honey bee.

PubMed

Johnson, B R

2010-05-01

Task allocation patterns should depend on the spatial distribution of work within the nest, variation in task demand, and the movement patterns of workers, however, relatively little research has focused on these topics. This study uses a spatially explicit agent based model to determine whether such factors alone can generate biases in task performance at the individual level in the honey bees, Apis mellifera. Specialization (bias in task performance) is shown to result from strong sampling error due to localized task demand, relatively slow moving workers relative to nest size, and strong spatial variation in task demand. To date, specialization has been primarily interpreted with the response threshold concept, which is focused on intrinsic (typically genotypic) differences between workers. Response threshold variation and sampling error due to spatial effects are not mutually exclusive, however, and this study suggests that both contribute to patterns of task bias at the individual level. While spatial effects are strong enough to explain some documented cases of specialization; they are relatively short term and not explanatory for long term cases of specialization. In general, this study suggests that the spatial layout of tasks and fluctuations in their demand must be explicitly controlled for in studies focused on identifying genotypic specialists.

Persistent spatial information in the frontal eye field during object-based short-term memory.

PubMed

Clark, Kelsey L; Noudoost, Behrad; Moore, Tirin

2012-08-08

Spatial attention is known to gate entry into visual short-term memory, and some evidence suggests that spatial signals may also play a role in binding features or protecting object representations during memory maintenance. To examine the persistence of spatial signals during object short-term memory, the activity of neurons in the frontal eye field (FEF) of macaque monkeys was recorded during an object-based delayed match-to-sample task. In this task, monkeys were trained to remember an object image over a brief delay, regardless of the locations of the sample or target presentation. FEF neurons exhibited visual, delay, and target period activity, including selectivity for sample location and target location. Delay period activity represented the sample location throughout the delay, despite the irrelevance of spatial information for successful task completion. Furthermore, neurons continued to encode sample position in a variant of the task in which the matching stimulus never appeared in their response field, confirming that FEF maintains sample location independent of subsequent behavioral relevance. FEF neurons also exhibited target-position-dependent anticipatory activity immediately before target onset, suggesting that monkeys predicted target position within blocks. These results show that FEF neurons maintain spatial information during short-term memory, even when that information is irrelevant for task performance.

Quantification and Systematic Characterization of Stuttering-Like Disfluencies in Acquired Apraxia of Speech.

PubMed

Bailey, Dallin J; Blomgren, Michael; DeLong, Catharine; Berggren, Kiera; Wambaugh, Julie L

2017-06-22

The purpose of this article is to quantify and describe stuttering-like disfluencies in speakers with acquired apraxia of speech (AOS), utilizing the Lidcombe Behavioural Data Language (LBDL). Additional purposes include measuring test-retest reliability and examining the effect of speech sample type on disfluency rates. Two types of speech samples were elicited from 20 persons with AOS and aphasia: repetition of mono- and multisyllabic words from a protocol for assessing AOS (Duffy, 2013), and connected speech tasks (Nicholas & Brookshire, 1993). Sampling was repeated at 1 and 4 weeks following initial sampling. Stuttering-like disfluencies were coded using the LBDL, which is a taxonomy that focuses on motoric aspects of stuttering. Disfluency rates ranged from 0% to 13.1% for the connected speech task and from 0% to 17% for the word repetition task. There was no significant effect of speech sampling time on disfluency rate in the connected speech task, but there was a significant effect of time for the word repetition task. There was no significant effect of speech sample type. Speakers demonstrated both major types of stuttering-like disfluencies as categorized by the LBDL (fixed postures and repeated movements). Connected speech samples yielded more reliable tallies over repeated measurements. Suggestions are made for modifying the LBDL for use in AOS in order to further add to systematic descriptions of motoric disfluencies in this disorder.

Chronic treatment with sulbutiamine improves memory in an object recognition task and reduces some amnesic effects of dizocilpine in a spatial delayed-non-match-to-sample task.

PubMed

Bizot, Jean-Charles; Herpin, Alexandre; Pothion, Stéphanie; Pirot, Sylvain; Trovero, Fabrice; Ollat, Hélène

2005-07-01

The effect of a sulbutiamine chronic treatment on memory was studied in rats with a spatial delayed-non-match-to-sample (DNMTS) task in a radial maze and a two trial object recognition task. After completion of training in the DNMTS task, animals were subjected for 9 weeks to daily injections of either saline or sulbutiamine (12.5 or 25 mg/kg). Sulbutiamine did not modify memory in the DNMTS task but improved it in the object recognition task. Dizocilpine, impaired both acquisition and retention of the DNMTS task in the saline-treated group, but not in the two sulbutiamine-treated groups, suggesting that sulbutiamine may counteract the amnesia induced by a blockade of the N-methyl-D-aspartate glutamate receptors. Taken together, these results are in favor of a beneficial effect of sulbutiamine on working and episodic memory.

Occupational exposures to styrene vapor in a manufacturing plant for fiber-reinforced composite wind turbine blades.

PubMed

Hammond, Duane; Garcia, Alberto; Feng, H Amy

2011-07-01

A utility-scale wind turbine blade manufacturing plant requested assistance from the National Institute for Occupational Safety and Health (NIOSH) in controlling worker exposures to styrene at a plant that produced 37 and 42 m long fiber-reinforced wind turbine blades. The plant requested NIOSH assistance because previous air sampling conducted by the company indicated concerns about peak styrene concentrations when workers entered the confined space inside of the wind turbine blade. NIOSH researchers conducted two site visits and collected personal breathing zone and area air samples while workers performed the wind turbine blade manufacturing tasks of vacuum-assisted resin transfer molding (VARTM), gelcoating, glue wiping, and installing the safety platform. All samples were collected during the course of normal employee work activities and analyzed for styrene using NIOSH Method 1501. All sampling was task based since full-shift sampling from a prior Occupational Safety and Health Administration (OSHA) compliance inspection did not show any exposures to styrene above the OSHA permissible exposure limit. During the initial NIOSH site visit, 67 personal breathing zone and 18 area air samples were collected while workers performed tasks of VARTM, gelcoating, glue wipe, and installation of a safety platform. After the initial site visit, the company made changes to the glue wipe task that eliminated the need for workers to enter the confined space inside of the wind turbine blade. During the follow-up site visit, 12 personal breathing zone and 8 area air samples were collected from workers performing the modified glue wipe task. During the initial site visit, the geometric means of the personal breathing zone styrene air samples were 1.8 p.p.m. (n = 21) for workers performing the VARTM task, 68 p.p.m. (n = 5) for workers installing a safety platform, and 340 p.p.m. (n = 14) for workers performing the glue wipe task, where n is the number of workers sampled for a given mean result. Gelcoating workers included job categories of millers, gelcoat machine operators, and gelcoaters. Geometric mean personal breathing zone styrene air samples were 150 p.p.m. (n = 6) for millers, 87 p.p.m. (n = 2) for the gelcoat machine operators, and 66 p.p.m. (n = 19) for gelcoaters. The geometric mean of the personal breathing zone styrene air samples from the glue wipe task measured during the follow-up site visit was 31 p.p.m. (n = 12). The closed molding VARTM process was very effective at controlling worker exposures to styrene. Personal breathing zone styrene air samples were reduced by an order of magnitude after changes were made to the glue wipe task. The company used chemical substitution to eliminate styrene exposure during the installation of the safety platform. Recommendations were provided to reduce styrene concentrations during gelcoating.

Children's Task Engagement during Challenging Puzzle Tasks

ERIC Educational Resources Information Center

Wang, Feihong; Algina, James; Snyder, Patricia; Cox, Martha

2017-01-01

We examined children's task engagement during a challenging puzzle task in the presence of their primary caregivers by using a representative sample of rural children from six high-poverty counties across two states. Weighted longitudinal confirmatory factor analysis and structural equation modeling were used to identify a task engagement factor…

Reinforcer Control by Comparison-Stimulus Color and Location in a Delayed Matching-to-Sample Task

ERIC Educational Resources Information Center

Alsop, Brent; Jones, B. Max

2008-01-01

Six pigeons were trained in a delayed matching-to-sample task involving bright- and dim-yellow samples on a central key, a five-peck response requirement to either sample, a constant 1.5-s delay, and the presentation of comparison stimuli composed of red on the left key and green on the right key or vice versa. Green-key responses were…

Psychopysics of Remembering: To Bias or Not to Bias?

ERIC Educational Resources Information Center

White, K. Geoffrey; Wixted, John T.

2010-01-01

Delayed matching to sample is typically a two-alternative forced-choice procedure with two sample stimuli. In this task the effects of varying the probability of reinforcers for correct choices and the resulting receiver operating characteristic are symmetrical. A version of the task where a sample is present on some trials and absent on others is…

Persistent Neuronal Firing in Primary Somatosensory Cortex in the Absence of Working Memory of Trial-Specific Features of the Sample Stimuli in a Haptic Working Memory Task

ERIC Educational Resources Information Center

Wang, Liping; Li, Xianchun; Hsiao, Steven S.; Bodner, Mark; Lenz, Fred; Zhou, Yong-Di

2012-01-01

Previous studies suggested that primary somatosensory (SI) neurons in well-trained monkeys participated in the haptic-haptic unimodal delayed matching-to-sample (DMS) task. In this study, 585 SI neurons were recorded in monkeys performing a task that was identical to that in the previous studies but without requiring discrimination and active…

Results from the interim salt disposition program macrobatch 10 tank 21H qualification samples

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

Peters, T. B.; Bannochie, C. J.

2017-02-23

Savannah River National Laboratory (SRNL) analyzed samples from Tank 21H in support of qualification of Macrobatch (Salt Batch) 10 for the Interim Salt Disposition Program (ISDP). This document reports characterization data on the samples of Tank 21H and fulfills the requirements of Deliverable 3 of the Technical Task Request (TTR). Further work will report the results of the Extraction-Scrub-Strip (ESS) testing (Task 5 of the TTR) using the Tank 21H material. Task 4 of the TTR (MST Strike) will not be completed for Salt Batch 10.

Reading skills, creativity, and insight: exploring the connections.

PubMed

Mourgues, Catalina V; Preiss, David D; Grigorenko, Elena L

2014-08-04

Studies of the relationship between creativity and specific reading disabilities have produced inconclusive results. We explored their relationship in a sample of 259 college students (age range: 17 to 38 years-old) from three Chilean universities. The students were tested on their verbal ability, creativity, and insight. A simple linear regression was performed on the complete sample, and on high- and low-achievement groups that were formed based on reading test scores. We observed a significant correlation in the total sample between outcomes on the verbal ability tasks, and on the creativity and insight tasks (range r =. 152 to r =. 356, ps <.001). Scores on the reading comprehension and phonological awareness tasks were the best predictors of performance on creativity and insight tasks (range β = .315 to β = .155, ps <.05). A comparison of the low- and high-scoring groups on verbal ability tasks yielded results to the same effect. These findings do not support the hypothesis that specific reading disability is associated with better performance on creative tasks. Instead, higher verbal ability was found to be associated with higher creativity and insight.

Midwives Performance in Early Detection of Growth and Development Irregularities of Children Based on Task Commitment

ERIC Educational Resources Information Center

Utami, Sri; Nursalam; Hargono, Rachmat; Susilaningrum, Rekawati

2016-01-01

The purpose of this study was to analyze the performance of midwives based on the task commitment. This was an observational analytic with cross sectional approach. Multistage random sampling was used to determine the public health center, proportional random sampling to selected participants. The samples were 222 midwives in the public health…

Balancing a U-Shaped Assembly Line by Applying Nested Partitions Method

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

Bhagwat, Nikhil V.

2005-01-01

In this study, we applied the Nested Partitions method to a U-line balancing problem and conducted experiments to evaluate the application. From the results, it is quite evident that the Nested Partitions method provided near optimal solutions (optimal in some cases). Besides, the execution time is quite short as compared to the Branch and Bound algorithm. However, for larger data sets, the algorithm took significantly longer times for execution. One of the reasons could be the way in which the random samples are generated. In the present study, a random sample is a solution in itself which requires assignment ofmore » tasks to various stations. The time taken to assign tasks to stations is directly proportional to the number of tasks. Thus, if the number of tasks increases, the time taken to generate random samples for the different regions also increases. The performance index for the Nested Partitions method in the present study was the number of stations in the random solutions (samples) generated. The total idle time for the samples can be used as another performance index. ULINO method is known to have used a combination of bounds to come up with good solutions. This approach of combining different performance indices can be used to evaluate the random samples and obtain even better solutions. Here, we used deterministic time values for the tasks. In industries where majority of tasks are performed manually, the stochastic version of the problem could be of vital importance. Experimenting with different objective functions (No. of stations was used in this study) could be of some significance to some industries where in the cost associated with creation of a new station is not the same. For such industries, the results obtained by using the present approach will not be of much value. Labor costs, task incompletion costs or a combination of those can be effectively used as alternate objective functions.« less

Task Analysis for Legal Assistant Program. Final Report.

ERIC Educational Resources Information Center

Schrader, Marvin A.; Knight, John

The Legal Assistant Task Analysis Project was undertaken to provide data related to the importance of tasks and the frequency of tasks that are, or could be, assigned to an assistant. In order to accomplish this, a task survey form was constructed and distributed to a sample of attorneys in (1) private practice, (2) companies or corporations, and…

2015 International PV Quality Assurance Task Force (PVQAT) Workshop |

Science.gov Websites

Photovoltaic Research | NREL International PV Quality Assurance Task Force (PVQAT) Workshop 2015 International PV Quality Assurance Task Force (PVQAT) Workshop Wednesday, February 25, 2015 Chairs : Tony Sample and Masaaki Yamamichi The 2015 International PV Quality Assurance Task Force (PVQAT

Performance tasks for operator-skills research.

DOT National Transportation Integrated Search

1966-06-01

The selection, development, and operation of several tasks for use in skilled-operator-performance research are described. The tasks are intended, collectively, to sample a broad spectrum of abilities required by complex operator systems; individuall...

Environmental research on a modified in situ oil shale task process. Progress report

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

Not Available

1980-05-01

This report summarizes the progress of the US Department of Energy's Oil Shale Task Force in its research program at the Occidental Oil Shale, Inc. facility at Logan Wash, Colorado. More specifically, the Task Force obtained samples from Retort 3E and Retort 6 and submitted these samples to a variety of analyses. The samples collected included: crude oil (Retort 6); light oil (Retort 6); product water (Retort 6); boiler blowdown (Retort 6); makeup water (Retort 6); mine sump water; groundwater; water from Retorts 1 through 5; retort gas (Retort 6); mine air; mine dust; and spent shale core (Retort 3E).more » The locations of the sampling points and methods used for collection and storage are discussed in Chapter 2 (Characterization). These samples were then distributed to the various laboratories and universities participating in the Task Force. For convenience in organizing the data, it is useful to group the work into three categories: Characterization, Leaching, and Health Effects. While many samples still have not been analyzed and much of the data remains to be interpreted, there are some preliminary conclusions the Task Force feels will be helpful in defining future needs and establishing priorities. It is important to note that drilling agents other than water were used in the recovery of the core from Retort 3E. These agents have been analyzed (see Table 12 in Chapter 2) for several constituents of interest. As a result some of the analyses of this core sample and leachates must be considered tentative.« less

Executive functioning and visual working memory.

PubMed

Lepach, Anja C; Pauls, Franz; Petermann, Franz

2015-01-01

The matter of modality is controversially discussed in the context of working memory (WM). There is evidence that modality-specific processes are accompanied by amodal processes to some extent. We investigated the relationship between executive-functioning tasks and visual WM (VWM) and were especially interested in the issue of amodal processes. Our correlational analyses suggest modality-independent relations of the tasks. We also aimed to quantify to what extent executive functioning is meaningful for VWM performances. We therefore estimated the relationship between executive tasks and VWM performances in a healthy (n = 710) and a clinical traumatic brain injury sample (n = 151) as well as in the combined total sample. The results indicate a substantial relevance of the verbal task for VWM performances in the total and the clinical sample but a low relevance in the healthy sample. These results could support assumptions of resource-depending differences in the relations of executive functioning and VWM but need further validation due to limitations of our study.

EEG based topography analysis in string recognition task

NASA Astrophysics Data System (ADS)

Ma, Xiaofei; Huang, Xiaolin; Shen, Yuxiaotong; Qin, Zike; Ge, Yun; Chen, Ying; Ning, Xinbao

2017-03-01

Vision perception and recognition is a complex process, during which different parts of brain are involved depending on the specific modality of the vision target, e.g. face, character, or word. In this study, brain activities in string recognition task compared with idle control state are analyzed through topographies based on multiple measurements, i.e. sample entropy, symbolic sample entropy and normalized rhythm power, extracted from simultaneously collected scalp EEG. Our analyses show that, for most subjects, both symbolic sample entropy and normalized gamma power in string recognition task are significantly higher than those in idle state, especially at locations of P4, O2, T6 and C4. It implies that these regions are highly involved in string recognition task. Since symbolic sample entropy measures complexity, from the perspective of new information generation, and normalized rhythm power reveals the power distributions in frequency domain, complementary information about the underlying dynamics can be provided through the two types of indices.

Impaired Decisional Impulsivity in Pathological Videogamers

PubMed Central

Irvine, Michael A.; Worbe, Yulia; Bolton, Sorcha; Harrison, Neil A.; Bullmore, Edward T.; Voon, Valerie

2013-01-01

Background Pathological gaming is an emerging and poorly understood problem. Impulsivity is commonly impaired in disorders of behavioural and substance addiction, hence we sought to systematically investigate the different subtypes of decisional and motor impulsivity in a well-defined pathological gaming cohort. Methods Fifty-two pathological gaming subjects and age-, gender- and IQ-matched healthy volunteers were tested on decisional impulsivity (Information Sampling Task testing reflection impulsivity and delay discounting questionnaire testing impulsive choice), and motor impulsivity (Stop Signal Task testing motor response inhibition, and the premature responding task). We used stringent diagnostic criteria highlighting functional impairment. Results In the Information Sampling Task, pathological gaming participants sampled less evidence prior to making a decision and scored fewer points compared with healthy volunteers. Gaming severity was also negatively correlated with evidence gathered and positively correlated with sampling error and points acquired. In the delay discounting task, pathological gamers made more impulsive choices, preferring smaller immediate over larger delayed rewards. Pathological gamers made more premature responses related to comorbid nicotine use. Greater number of hours played also correlated with a Motivational Index. Greater frequency of role playing games was associated with impaired motor response inhibition and strategy games with faster Go reaction time. Conclusions We show that pathological gaming is associated with impaired decisional impulsivity with negative consequences in task performance. Decisional impulsivity may be a potential target in therapeutic management. PMID:24146789

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.

Rapid Automated Sample Preparation for Biological Assays

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

Shusteff, M

Our technology utilizes acoustic, thermal, and electric fields to separate out contaminants such as debris or pollen from environmental samples, lyse open cells, and extract the DNA from the lysate. The objective of the project is to optimize the system described for a forensic sample, and demonstrate its performance for integration with downstream assay platforms (e.g. MIT-LL's ANDE). We intend to increase the quantity of DNA recovered from the sample beyond the current {approx}80% achieved using solid phase extraction methods. Task 1: Develop and test an acoustic filter for cell extraction. Task 2: Develop and test lysis chip. Task 3:more » Develop and test DNA extraction chip. All chips have been fabricated based on the designs laid out in last month's report.« less

Development of a Methodology for Assessing Aircrew Workloads.

DTIC Science & Technology

1981-11-01

Workload Feasibility Study. .. ...... 52 Subjects. .. .............. ........ 53 Equipment .. ............... ....... 53 Date Analysis ... analysis ; simulation; standard time systems; switching synthetic time systems; task activities; task interference; time study; tracking; workload; work sampl...standard data systems, information content analysis , work sampling and job evaluation. Con- ventional methods were found to be deficient in accounting

Principles of Work Sample Testing. 3. Construction and Evaluation of Work Sample Tests

DTIC Science & Technology

1979-04-01

with an enphasis on examining alternative explanations for scores), and in some cases evidence of predictive or other criterion-related corre- lations...34 Generalizability in this case is a function of the number of behavioral elements (task elements) in one component task that are also included in one or...evaluation of the results of task per- formance. In either case measurement depends on some form of observa- tion or an observational aid. It is Lnlikely

A Developmental Neuroimaging Investigation of the Change Paradigm

ERIC Educational Resources Information Center

Thomas, Laura A.; Hall, Julie M.; Skup, Martha; Jenkins, Sarah E.; Pine, Daniel S.; Leibenluft, Ellen

2011-01-01

This neuroimaging study examines the development of cognitive flexibility using the Change task in a sample of youths and adults. The Change task requires subjects to inhibit a prepotent response and substitute an alternative response, and the task incorporates an algorithm that adjusts task difficulty in response to subject performance. Data from…

Recent progress of task-specific ionic liquids in chiral resolution and extraction of biological samples and metal ions.

PubMed

Wu, Datong; Cai, Pengfei; Zhao, Xiaoyong; Kong, Yong; Pan, Yuanjiang

2018-01-01

Ionic liquids have been functionalized for modern applications. The functional ionic liquids are also called task-specific ionic liquids. Various task-specific ionic liquids with certain groups have been constructed and exploited widely in the field of separation. To take advantage of their properties in separation science, task-specific ionic liquids are generally used in techniques such as liquid-liquid extraction, solid-phase extraction, gas chromatography, high-performance liquid chromatography, and capillary electrophoresis. This review mainly covers original research papers published in the last five years, and we will focus on task-specific ionic liquids as the chiral selectors in chiral resolution and as extractant or sensor for biological samples and metal ion purification. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Similar Brain Activation during False Belief Tasks in a Large Sample of Adults with and without Autism

PubMed Central

Dufour, Nicholas; Redcay, Elizabeth; Young, Liane; Mavros, Penelope L.; Moran, Joseph M.; Triantafyllou, Christina; Gabrieli, John D. E.; Saxe, Rebecca

2013-01-01

Reading about another person’s beliefs engages ‘Theory of Mind’ processes and elicits highly reliable brain activation across individuals and experimental paradigms. Using functional magnetic resonance imaging, we examined activation during a story task designed to elicit Theory of Mind processing in a very large sample of neurotypical (N = 462) individuals, and a group of high-functioning individuals with autism spectrum disorders (N = 31), using both region-of-interest and whole-brain analyses. This large sample allowed us to investigate group differences in brain activation to Theory of Mind tasks with unusually high sensitivity. There were no differences between neurotypical participants and those diagnosed with autism spectrum disorder. These results imply that the social cognitive impairments typical of autism spectrum disorder can occur without measurable changes in the size, location or response magnitude of activity during explicit Theory of Mind tasks administered to adults. PMID:24073267

Similar brain activation during false belief tasks in a large sample of adults with and without autism.

PubMed

Dufour, Nicholas; Redcay, Elizabeth; Young, Liane; Mavros, Penelope L; Moran, Joseph M; Triantafyllou, Christina; Gabrieli, John D E; Saxe, Rebecca

2013-01-01

Reading about another person's beliefs engages 'Theory of Mind' processes and elicits highly reliable brain activation across individuals and experimental paradigms. Using functional magnetic resonance imaging, we examined activation during a story task designed to elicit Theory of Mind processing in a very large sample of neurotypical (N = 462) individuals, and a group of high-functioning individuals with autism spectrum disorders (N = 31), using both region-of-interest and whole-brain analyses. This large sample allowed us to investigate group differences in brain activation to Theory of Mind tasks with unusually high sensitivity. There were no differences between neurotypical participants and those diagnosed with autism spectrum disorder. These results imply that the social cognitive impairments typical of autism spectrum disorder can occur without measurable changes in the size, location or response magnitude of activity during explicit Theory of Mind tasks administered to adults.

Women with borderline personality disorder do not show altered BOLD responses during response inhibition.

PubMed

van Eijk, Julia; Sebastian, Alexandra; Krause-Utz, Annegret; Cackowski, Sylvia; Demirakca, Traute; Biedermann, Sarah V; Lieb, Klaus; Bohus, Martin; Schmahl, Christian; Ende, Gabriele; Tüscher, Oliver

2015-12-30

Impulsivity is central to borderline personality disorder (BPD). Response inhibition, addressing the ability to suppress or stop actions, is one aspect of behavioral impulse control which is frequently used to assess impulsivity. BPD patients display deficits in response inhibition under stress condition or negative emotions. We assessed whether response inhibition and its neural underpinnings are impaired in BPD when tested in an emotionally neutral setting and when co-morbid attention-deficit/hyperactivity disorder (ADHD) is excluded. To this end, we studied response inhibition in unmedicated BPD patients and healthy controls (HC) in two independent samples using functional magnetic resonance imaging during Simon-, Go/nogo-, and Stopsignal tasks. BPD patients and HC did not differ significantly in their performance in the Go/nogo and the Stopsignal tasks. Response interference in the Simon task was increased in BPD patients in one sample, but this could not be replicated in the second sample. In both samples, no significant differences in brain activation patterns during any of the tasks were present while the neural impulse control network was robustly activated during the inhibition tasks in both groups. Our results provide evidence that under emotionally neutral conditions response inhibition is not impaired in patients with BPD without co-occurring ADHD. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Biomonitoring of N-ethyl-2-pyrrolidone in automobile varnishers.

PubMed

Koslitz, Stephan; Meier, Swetlana; Schindler, Birgit Karin; Weiss, Tobias; Koch, Holger Martin; Brüning, Thomas; Käfferlein, Heiko Udo

2014-12-01

N-alkyl-2-pyrrolidones are important organic solvents for varnishes in industry. This study investigates exposure to N-ethyl-2-pyrrolidone (NEP) in varnishing of hard plastic components in an automobile plant. Two specific biomarkers of exposure, 5-hydroxy-N-ethyl-2-pyrrolidone (5-HNEP) and 2-hydroxy-N-ethylsuccinimide (2-HESI), were analyzed in urine samples of 14 workers. For this purpose, pre-shift, post-shift and next day pre-shift urine samples were collected midweek. Twelve workers performed regular work tasks (loading, wiping and packing), whereas two workers performed special work tasks including cleaning the sprayer system with organic solvents containing N-alkyl-2-pyrrolidones. Spot urine samples of nine non-exposed persons of the same plant served as controls. Median post-shift urinary levels of workers with regular work tasks (5-HNEP: 0.15 mg/L; 2-HESI: 0.19 mg/L) were ∼5-fold higher compared to the controls (0.03 mg/L each). Continuously increasing metabolite levels, from pre-shift via post-shift to pre-shift samples of the following day, were observed in particular for the two workers with the special working tasks. Maximum levels were 31.01 mg/L (5-HNEP) and 8.45 mg/L (2-HESI). No clear trend was evident for workers with regular working tasks. In summary, we were able to show that workers can be exposed to NEP during varnishing tasks in the automobile industry. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Results of Hg speciation testing on tank 39 and 1Q16 tank 50 samples

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

Bannochie, C. J.

2016-03-07

The Savannah River National Laboratory (SRNL) was tasked with preparing and shipping samples for Hg speciation by Eurofins Frontier Global Sciences, Inc. in Seattle, WA on behalf of the Savannah River Remediation (SRR) Mercury Task Team.i,ii The seventeenth shipment of samples was designated to include two Tank 39 samples and the 1Q16 Tank 50 Quarterly WAC sample. The surface Tank 39 sample was pulled at 262.1” from the tank bottom, and the depth Tank 39 sample was pulled at 95” from the tank bottom. The 1Q16 Tank 50 WAC sample was drawn from the 1-L variable depth sample received bymore » SRNL.« less

Soldier-Computer Interface

DTIC Science & Technology

2015-01-27

placed on the user by the required tasks. Design areas that are of concern include seating , input and output device location and design , ambient...software, hardware, and workspace design for the test function of operability that influence operator performance in a computer-based system. 15...PRESENTATION ................... 23 APPENDIX A. SAMPLE DESIGN CHECKLISTS ...................................... A-1 B. SAMPLE TASK CHECKLISTS

Over-Selectivity as a Learned Response

ERIC Educational Resources Information Center

Reed, Phil; Petrina, Neysa; McHugh, Louise

2011-01-01

An experiment investigated the effects of different levels of task complexity in pre-training on over-selectivity in a subsequent match-to-sample (MTS) task. Twenty human participants were divided into two groups; exposed either to a 3-element, or a 9-element, compound stimulus as a sample during MTS training. After the completion of training,…

An Approximation of an Instructional Model for Developing Home Living Skills in Severely Handicapped Students.

ERIC Educational Resources Information Center

Hamre, S.

The author discusses the need for severely handicapped students to acquire basic home living skills, reviews task analysis principles, and provides sample instructional programs. Listed are basic grooming, dressing, domestic maintenance, and cooking skills. A sample task analysis procedure is demonstrated for the skill of brushing teeth. Reported…

A study of performance assessment task organization in high school optics

NASA Astrophysics Data System (ADS)

Zawicki, Joseph Leo

2002-01-01

This investigation was undertaken to validate three performance assessment tasks in high school physics. The tasks that were studied were developed around three organizational models of performance assessments: integrated, independent and surrogate. The integrated model required students to answer questions, make observations and demonstrate skills related to the index of refraction of a particular material. All of the questions and activities the students completed were related to a sample of a particular plastic sample that was the focus of this task. The independent model is analogous to the station model that is currently used on three New York State assessments: the Grade 4 - Elementary Science Program Evaluation Test, the Intermediate Level Science (ILS) Test, and the Physical Setting: Earth Science Regents Exam. Students took measurements related to the index of refraction of a plastic sample that was the focus of the initial portion of this task; the remaining questions on the assessment were generally related to the concept of the index of refraction but did not refer back to the initial sample. The final task organization followed the surrogate model. In this model, students reviewed data that was collected and analyzed by other (fictitious) students. The students completing this task were asked to review the work presented on this assessment for errors; they evaluated the conclusions and statements presented on the assessment. Students were also asked to determine if the student work was acceptable or if this investigation should be repeated. Approximately 300 students from urban, suburban and rural districts across Western New York State participated in the study. The tasks were administered during the spring semester of the 2000--2001 school year. The participating schools had at least covered the topic of refraction, both in classroom lectures and in laboratory activities. Each student completed only one form of the task---either the integrated, the independent or the surrogate form. A set of ten questions, compiled from past New York State Regents Examinations in Physics, was used as an additional measurement of student conceptual understanding. This question set was identified as the "Optics Baseline Test" (OBT). Additionally, classroom teachers ranked the academic performance of each of the students in their classroom on the outcomes of the physics course; these rankings were compared with student scores on the performance assessment tasks. The process skills incorporated within the individual questions on each task were reviewed by a panel of expert teachers. Student scores on the tasks themselves were examined using a principal component analysis. This analysis provided support for the process skill subtests organized around the general process skills of planning, performing, and reasoning. Scoring guides and inter-rater reliabilities were established for each task. The reliabilities for tasks, subtests and questions were fairly high, indicting adequate task reliability. Correlations between student performance on the individual tasks and the OBT were not significant. Teacher ranking of student achievement in individual classrooms also failed to correlate significantly with student performance on tasks. The lack of correlation could be attributed to several factors, including (among others) a wide range of student opportunities to learn from the seven schools in the sample. As has been reported in the performance assessment literature, there were no significant differences between the performance of male and female students. (Abstract shortened by UMI.)

Task-based exposure assessment of nanoparticles in the workplace

NASA Astrophysics Data System (ADS)

Ham, Seunghon; Yoon, Chungsik; Lee, Euiseung; Lee, Kiyoung; Park, Donguk; Chung, Eunkyo; Kim, Pilje; Lee, Byoungcheun

2012-09-01

Although task-based sampling is, theoretically, a plausible approach to the assessment of nanoparticle exposure, few studies using this type of sampling have been published. This study characterized and compared task-based nanoparticle exposure profiles for engineered nanoparticle manufacturing workplaces (ENMW) and workplaces that generated welding fumes containing incidental nanoparticles. Two ENMW and two welding workplaces were selected for exposure assessments. Real-time devices were utilized to characterize the concentration profiles and size distributions of airborne nanoparticles. Filter-based sampling was performed to measure time-weighted average (TWA) concentrations, and off-line analysis was performed using an electron microscope. Workplace tasks were recorded by researchers to determine the concentration profiles associated with particular tasks/events. This study demonstrated that exposure profiles differ greatly in terms of concentrations and size distributions according to the task performed. The size distributions recorded during tasks were different from both those recorded during periods with no activity and from the background. The airborne concentration profiles of the nanoparticles varied according to not only the type of workplace but also the concentration metrics. The concentrations measured by surface area and the number concentrations measured by condensation particle counter, particulate matter 1.0, and TWA mass concentrations all showed a similar pattern, whereas the number concentrations measured by scanning mobility particle sizer indicated that the welding fume concentrations at one of the welding workplaces were unexpectedly higher than were those at workplaces that were engineering nanoparticles. This study suggests that a task-based exposure assessment can provide useful information regarding the exposure profiles of nanoparticles and can therefore be used as an exposure assessment tool.

RACE/A: An Architectural Account of the Interactions between Learning, Task Control, and Retrieval Dynamics

ERIC Educational Resources Information Center

van Maanen, Leendert; van Rijn, Hedderik; Taatgen, Niels

2012-01-01

This article discusses how sequential sampling models can be integrated in a cognitive architecture. The new theory Retrieval by Accumulating Evidence in an Architecture (RACE/A) combines the level of detail typically provided by sequential sampling models with the level of task complexity typically provided by cognitive architectures. We will use…

The Use of Consciousness-Raising Tasks in Learning and Teaching of Subject-Verb Agreement

ERIC Educational Resources Information Center

Idek, Sirhajwan; Fong, Lee Lai; Sidhu, Gurnam Kaur

2013-01-01

This study investigates the use of two types of Consciousness-Raising (CR) tasks in learning Subject-Verb Agreement (SVA). The sample consisted of 28 Form 2 students who were divided into two groups. Group 1 was assigned with Grammaticality Judgment (GJ) tasks and Group 2 received Sentence Production (SP) tasks for eight weeks. Learners were given…

Writing-Reading Relationships: Effectiveness of Writing Activities as Pre-Reading Tasks to Enhance L2 Inferential Reading Comprehension

ERIC Educational Resources Information Center

Wickramaarachchi, Thilina Indrajie

2014-01-01

The study examines the interaction between reading and writing processes in general and more specifically the impact of pre-reading tasks incorporating writing tasks (referred to as "prw tasks") in helping the development of inferential reading comprehension. A sample of 70 first year ESL students of the University of Kelaniya were…

DEVELOPMENT AND APPLICATION OF METHODS TO ASSESS HUMAN EXPOSURE TO PESTICIDES

EPA Science Inventory

Note: this task is schedule to end September 2003. Two tasks will take its place: method development for emerging pesticides including chiral chemistry applications, and in-house laboratory operations. Field sampling methods are covered under a new task proposed this year.
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Final report for 105-N Basin sediment disposition task, phase 2 -- samples BOMPC8 and BOMPC9

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

Esch, R.A.

1998-02-05

This document is the final report deliverable for Phase 2 analytical work for the 105-N Basin Sediment Disposition Task. On December 23, 1997, ten samples were received at the 222-S Laboratory as follows: two (2) bottles of potable water, six (6) samples for process control testing and two (2) samples for characterization. Analyses were performed in accordance with the Letter of Instruction for Phase 2 Analytical Work for the 105-N Basin Sediment Disposition Task (Logan and Kessner, 1997) (Attachment 7) and 105-N Basin Sediment Disposition Phase-Two Sampling and Analysis Plan (SAP) (Smith, 1997). The analytical results are included in Tablemore » 1. This document provides the values of X/Qs for the onsite and offsite receptors, taking into account the building wake and the atmospheric stability effects. X/Qs values for the potential fire accident were also calculated. In addition, the unit dose were calculated for the mixtures of isotopes.« less

Preliminary evaluation of an analog procedure to assess acceptability of intimate partner violence against women: the Partner Violence Acceptability Movie Task

PubMed Central

Gracia, Enrique; Rodriguez, Christina M.; Lila, Marisol

2015-01-01

Acceptability of partner violence against women is a risk factor linked to its perpetration, and to public, professionals’ and victims’ responses to this behavior. Research on the acceptability of violence in intimate partner relationships is, however, limited by reliance solely on self-reports that often provide distorted or socially desirable accounts that may misrepresent respondents’ attitudes. This study presents data on the development and initial validation of a new analog task assessing respondents’ acceptability of physical violence toward women in intimate relationships: the Partner Violence Acceptability Movie Task (PVAM). This new analog task is intended to provide a more implicit measure of the acceptability of partner violence against women. For this analog task, clips were extracted from commercially available films (90-s segments) portraying partner violence. Two independent samples were used to develop and evaluate the PVAM: a sample of 245 undergraduate students and a sample of 94 male intimate partner violence offenders. This new analog task demonstrated acceptable internal consistency. Results also indicated adequate construct validity. Both perpetrators and undergraduates scoring high in the PVAM also scored higher in self-reported justifications of partner abuse. Perpetrators of partner violence scored significantly higher in acceptability of partner violence than the undergraduate sample (both male and female students), and male students scored higher than females. These preliminary results suggest that the PVAM may be a promising tool to assess the acceptability of violence in intimate partner relationships, highlighting the need to consider alternatives to self-report to evaluate potential beliefs about partner violence. PMID:26528220

Rigorous Training of Dogs Leads to High Accuracy in Human Scent Matching-To-Sample Performance

PubMed Central

Marchal, Sophie; Bregeras, Olivier; Puaux, Didier; Gervais, Rémi; Ferry, Barbara

2016-01-01

Human scent identification is based on a matching-to-sample task in which trained dogs are required to compare a scent sample collected from an object found at a crime scene to that of a suspect. Based on dogs’ greater olfactory ability to detect and process odours, this method has been used in forensic investigations to identify the odour of a suspect at a crime scene. The excellent reliability and reproducibility of the method largely depend on rigor in dog training. The present study describes the various steps of training that lead to high sensitivity scores, with dogs matching samples with 90% efficiency when the complexity of the scents presented during the task in the sample is similar to that presented in the in lineups, and specificity reaching a ceiling, with no false alarms in human scent matching-to-sample tasks. This high level of accuracy ensures reliable results in judicial human scent identification tests. Also, our data should convince law enforcement authorities to use these results as official forensic evidence when dogs are trained appropriately. PMID:26863620

PAVENET OS: A Compact Hard Real-Time Operating System for Precise Sampling in Wireless Sensor Networks

NASA Astrophysics Data System (ADS)

Saruwatari, Shunsuke; Suzuki, Makoto; Morikawa, Hiroyuki

The paper shows a compact hard real-time operating system for wireless sensor nodes called PAVENET OS. PAVENET OS provides hybrid multithreading: preemptive multithreading and cooperative multithreading. Both of the multithreading are optimized for two kinds of tasks on wireless sensor networks, and those are real-time tasks and best-effort ones. PAVENET OS can efficiently perform hard real-time tasks that cannot be performed by TinyOS. The paper demonstrates the hybrid multithreading realizes compactness and low overheads, which are comparable to those of TinyOS, through quantitative evaluation. The evaluation results show PAVENET OS performs 100 Hz sensor sampling with 0.01% jitter while performing wireless communication tasks, whereas optimized TinyOS has 0.62% jitter. In addition, PAVENET OS has a small footprint and low overheads (minimum RAM size: 29 bytes, minimum ROM size: 490 bytes, minimum task switch time: 23 cycles).

Video-task assessment of learning and memory in Macaques (Macaca mulatta) - Effects of stimulus movement on performance

NASA Technical Reports Server (NTRS)

Washburn, David A.; Hopkins, William D.; Rumbaugh, Duane M.

1989-01-01

Effects of stimulus movement on learning, transfer, matching, and short-term memory performance were assessed with 2 monkeys using a video-task paradigm in which the animals responded to computer-generated images by manipulating a joystick. Performance on tests of learning set, transfer index, matching to sample, and delayed matching to sample in the video-task paradigm was comparable to that obtained in previous investigations using the Wisconsin General Testing Apparatus. Additionally, learning, transfer, and matching were reliably and significantly better when the stimuli or discriminanda moved than when the stimuli were stationary. External manipulations such as stimulus movement may increase attention to the demands of a task, which in turn should increase the efficiency of learning. These findings have implications for the investigation of learning in other populations, as well as for the application of the video-task paradigm to comparative study.

Persistent spatial information in the FEF during object-based short-term memory does not contribute to task performance.

PubMed

Clark, Kelsey L; Noudoost, Behrad; Moore, Tirin

2014-06-01

We previously reported the existence of a persistent spatial signal in the FEF during object-based STM. This persistent activity reflected the location at which the sample appeared, irrespective of the location of upcoming targets. We hypothesized that such a spatial signal could be used to maintain or enhance object-selective memory activity elsewhere in cortex, analogous to the role of a spatial signal during attention. Here, we inactivated a portion of the FEF with GABAa agonist muscimol to test whether the observed activity contributes to object memory performance. We found that, although RTs were slowed for saccades into the inactivated portion of retinotopic space, performance for samples appearing in that region was unimpaired. This contrasts with the devastating effects of the same FEF inactivation on purely spatial working memory, as assessed with the memory-guided saccade task. Thus, in a task in which a significant fraction of FEF neurons displayed persistent, sample location-based activity, disrupting this activity had no impact on task performance.

Episodic memory change in late adulthood: generalizability across samples and performance indices.

PubMed

Dixon, Roger A; Wahlin, Ake; Maitland, Scott B; Hultsch, David F; Hertzog, Christopher; Bäckman, Lars

2004-07-01

Younger adults recall more information from episodic memory tasks than do older adults. Because longitudinal studies are rare and often incompatible, the extent of actual late-life memory change is not well established. We assemble two different longitudinal samples of normal older adults, each of which is tested twice at a 3-year interval, using a large battery of episodic memory indicators. Together, two-wave data from both the Victoria Longitudinal Study in Canada (n = 400) and the Kungsholmen Project in Sweden (n = 168) cover a 40-year span of adulthood, ranging from 54 to 94 years of age. Principal memory tasks include categorizable word lists, story recall, and random word lists, as well as indicators of cognitive support. Overall, an examination of performance on sets of common and complementary episodic tasks reveals that, for both samples, actual 3-year changes are modest and that, when decline occurs, it is gradual. The exception-greater decline for more supported tasks-suggests that these may be especially sensitive to late-life changes.

Pencil grasp and children's handwriting legibility during different-length writing tasks.

PubMed

Dennis, J L; Swinth, Y

2001-01-01

This study examined the influence ofpencil grasp on handwriting legibility during both short and long writing tasks in 46fourth-grade students who were typically developing. Matched samples were used to controlfor variability. Regular classroom writing assignments were scoredfor word and letter legibility, and scores were compared using a mixed repeated-measures analysis of variance design. The two independent variables were pencil grasp (dynamic tripod grasp vs. atypical grasp) and task length (short vs. long). A significant difference was found between the letter legibility scores on the short task and the letter legibility scores on the long task. Students' legibility was greater on the short task than on the long task across both grasp conditions. No significant difference was found in scores between students who used dynamic tripod grasps and those who used atypical grasps, nor was there a significant interaction between grasp and task length. No significant differences were found between word legibility scores. The results indicate that although the students in this study wrote more legibly on the short task than on the long task, the type of grasp they used did not affect their legibility. Because of the limited sample size, the results of this study should be interpreted cautiously. More research in handwriting performance and pencil grasp is needed to provide clear expectations and treatment options for students.

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

Monroy, G.J. Keene, F.E.

A study to address Ambos (Both) Nogales' air quality concerns was conducted by the Arizona Department of Environmental Quality (ADEQ), in conjunction with Mexico's Secretaria de Medio Ambiente, Recursos Naturales y Pesca (SEMARNAP), from 1994 to 1998. The study, which is part of the US-Mexico Border XXI Program, consisted of the following tasks: (1) air sampling/monitoring; (2) emissions inventory; (3) meteorological modeling; and, (4) health risk assessment. The following types of samples were collected: particulate matter (PM); volatile organic compounds; semi-volatile organic compounds; and aldehydes. All samples were collected for a 24-hour period; every sixth day during the warm monthsmore » (April--September), and every third day during the cold months (October--March). There were a total of six sampling stations; three on each side of the border. PM samples were collected at all six sites, while samples for Hazardous Air Pollutants (HAPs) were collected at four of those sites. Sample analyses were performed at the Desert Research Institute (DRI) in Reno, Nevada. Furthermore, four of the sites were outfitted with meteorological equipment, in order to gather data on wind speed and direction. PM and meteorological data are still being collected at two sampling sites, one in Arizona and one in Sonora. An emissions inventory of point, mobile and area sources for the Ambos Nogales area (12 x 19 km. domain), was developed following completion of the sampling effort. In order to accomplish this task, ADEQ contracted the services of RADIAN International and Powers Engineering; which in turn enlisted the services of Heuristica Ambiental of Hermosillo, Sonora. This task was completed in July, 1997. Vehicular emissions were found to be one of the main contributors of air emissions in the Ambos Nogales area. The third task of this project consisted developing meteorological models of the study area.« less

Bounds on the sample complexity for private learning and private data release

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

Kasiviswanathan, Shiva; Beime, Amos; Nissim, Kobbi

2009-01-01

Learning is a task that generalizes many of the analyses that are applied to collections of data, and in particular, collections of sensitive individual information. Hence, it is natural to ask what can be learned while preserving individual privacy. [Kasiviswanathan, Lee, Nissim, Raskhodnikova, and Smith; FOCS 2008] initiated such a discussion. They formalized the notion of private learning, as a combination of PAC learning and differential privacy, and investigated what concept classes can be learned privately. Somewhat surprisingly, they showed that, ignoring time complexity, every PAC learning task could be performed privately with polynomially many samples, and in many naturalmore » cases this could even be done in polynomial time. While these results seem to equate non-private and private learning, there is still a significant gap: the sample complexity of (non-private) PAC learning is crisply characterized in terms of the VC-dimension of the concept class, whereas this relationship is lost in the constructions of private learners, which exhibit, generally, a higher sample complexity. Looking into this gap, we examine several private learning tasks and give tight bounds on their sample complexity. In particular, we show strong separations between sample complexities of proper and improper private learners (such separation does not exist for non-private learners), and between sample complexities of efficient and inefficient proper private learners. Our results show that VC-dimension is not the right measure for characterizing the sample complexity of proper private learning. We also examine the task of private data release (as initiated by [Blum, Ligett, and Roth; STOC 2008]), and give new lower bounds on the sample complexity. Our results show that the logarithmic dependence on size of the instance space is essential for private data release.« less

Transfer Effects to a Multimodal Dual-Task after Working Memory Training and Associated Neural Correlates in Older Adults - A Pilot Study.

PubMed

Heinzel, Stephan; Rimpel, Jérôme; Stelzel, Christine; Rapp, Michael A

2017-01-01

Working memory (WM) performance declines with age. However, several studies have shown that WM training may lead to performance increases not only in the trained task, but also in untrained cognitive transfer tasks. It has been suggested that transfer effects occur if training task and transfer task share specific processing components that are supposedly processed in the same brain areas. In the current study, we investigated whether single-task WM training and training-related alterations in neural activity might support performance in a dual-task setting, thus assessing transfer effects to higher-order control processes in the context of dual-task coordination. A sample of older adults (age 60-72) was assigned to either a training or control group. The training group participated in 12 sessions of an adaptive n-back training. At pre and post-measurement, a multimodal dual-task was performed in all participants to assess transfer effects. This task consisted of two simultaneous delayed match to sample WM tasks using two different stimulus modalities (visual and auditory) that were performed either in isolation (single-task) or in conjunction (dual-task). A subgroup also participated in functional magnetic resonance imaging (fMRI) during the performance of the n-back task before and after training. While no transfer to single-task performance was found, dual-task costs in both the visual modality ( p < 0.05) and the auditory modality ( p < 0.05) decreased at post-measurement in the training but not in the control group. In the fMRI subgroup of the training participants, neural activity changes in left dorsolateral prefrontal cortex (DLPFC) during one-back predicted post-training auditory dual-task costs, while neural activity changes in right DLPFC during three-back predicted visual dual-task costs. Results might indicate an improvement in central executive processing that could facilitate both WM and dual-task coordination.

Transfer Effects to a Multimodal Dual-Task after Working Memory Training and Associated Neural Correlates in Older Adults – A Pilot Study

PubMed Central

Heinzel, Stephan; Rimpel, Jérôme; Stelzel, Christine; Rapp, Michael A.

2017-01-01

Working memory (WM) performance declines with age. However, several studies have shown that WM training may lead to performance increases not only in the trained task, but also in untrained cognitive transfer tasks. It has been suggested that transfer effects occur if training task and transfer task share specific processing components that are supposedly processed in the same brain areas. In the current study, we investigated whether single-task WM training and training-related alterations in neural activity might support performance in a dual-task setting, thus assessing transfer effects to higher-order control processes in the context of dual-task coordination. A sample of older adults (age 60–72) was assigned to either a training or control group. The training group participated in 12 sessions of an adaptive n-back training. At pre and post-measurement, a multimodal dual-task was performed in all participants to assess transfer effects. This task consisted of two simultaneous delayed match to sample WM tasks using two different stimulus modalities (visual and auditory) that were performed either in isolation (single-task) or in conjunction (dual-task). A subgroup also participated in functional magnetic resonance imaging (fMRI) during the performance of the n-back task before and after training. While no transfer to single-task performance was found, dual-task costs in both the visual modality (p < 0.05) and the auditory modality (p < 0.05) decreased at post-measurement in the training but not in the control group. In the fMRI subgroup of the training participants, neural activity changes in left dorsolateral prefrontal cortex (DLPFC) during one-back predicted post-training auditory dual-task costs, while neural activity changes in right DLPFC during three-back predicted visual dual-task costs. Results might indicate an improvement in central executive processing that could facilitate both WM and dual-task coordination. PMID:28286477

Athletes' perceptions of coaching competency and team conflict in sport teams: A multilevel analysis.

PubMed

González-Ponce, I; Leo, F M; Jiménez, R; Sánchez-Oliva, D; Sarmento, H; Figueiredo, A; García-Calvo, T

2018-04-23

The purpose of this study was to examine the relationship between coaching competency and team conflict, at individual and team levels, over the season. The participants were professional female and male soccer players, who participated in the First and Second Division. A longitudinal study was performed. At Time 1, the sample of participants consisted of 581 soccer players aged between 15 and 39 years. At Time 2, 549 players were recruited from the original sample aged between 15 and 37 years. Finally, at Time 3, the sample comprised 576 players aged between 15 and 37 years. All participants completed a multi-section questionnaire assessing coaching competency (motivation, game strategy, technique competency, and character-building competency) and team conflict (task conflict and relationship conflict). Results showed that both task and relationship conflict increased significantly over time. Multilevel modelling analysis showed that game strategy and character-building competencies negatively predicted both task and relationship conflicts at the individual level, whereas motivation competency was also added as a significant predictor of task conflict at the team level. Moreover, technique competency positively predicted task conflict at the team level. The current study suggests the importance of coaching competency in group dynamics in sport.

Comparing the Values Hierarchy of the Kentucky Department of Education's Character/Values Task Force. Comparing a Character/Values Task Force to a National Sample.

ERIC Educational Resources Information Center

Butler, Fonda P.

In March 1989, the Kentucky Department of Education assembled a task force to make recommendations regarding the issue of teaching values and character in public schools in Kentucky. The 23-member task force represented educators, parents, the legislature, state and local school boards, law enforcement agencies, higher education, Catholic…

Context effects in a temporal discrimination task" further tests of the Scalar Expectancy Theory and Learning-to-Time models.

PubMed

Arantes, Joana; Machado, Armando

2008-07-01

Pigeons were trained on two temporal bisection tasks, which alternated every two sessions. In the first task, they learned to choose a red key after a 1-s signal and a green key after a 4-s signal; in the second task, they learned to choose a blue key after a 4-s signal and a yellow key after a 16-s signal. Then the pigeons were exposed to a series of test trials in order to contrast two timing models, Learning-to-Time (LeT) and Scalar Expectancy Theory (SET). The models made substantially different predictions particularly for the test trials in which the sample duration ranged from 1 s to 16 s and the choice keys were Green and Blue, the keys associated with the same 4-s samples: LeT predicted that preference for Green should increase with sample duration, a context effect, but SET predicted that preference for Green should not vary with sample duration. The results were consistent with LeT. The present study adds to the literature the finding that the context effect occurs even when the two basic discriminations are never combined in the same session.

In search of a representative sample of residential building work.

PubMed

Lobb, Brenda; Woods, Gregory R

2012-09-01

Most research investigating injuries in construction work is limited by reliance on work samples unrepresentative of the multiple, variable-cycle tasks involved, resulting in incomplete characterisation of ergonomic exposures. In this case study, a participatory approach was used including hierarchical task analysis and site observations of a typical team of house builders in New Zealand, over several working days, to obtain a representative work sample. The builders' work consisted of 14 goal-defined jobs using varying subsets of 15 task types, each taking from less than 1 s to more than 1 h and performed in a variety of postures. Task type and duration varied within and between participants and days, although all participants spent at least 25% of the time moving from place to place, mostly carrying materials, and more than half the time either reaching up or bending down to work. This research has provided a description of residential building work based on a work sample more nearly representative than those previously published and has demonstrated a simple, low-cost but robust field observation method that can provide a valid basis for further study of hazard exposures. Copyright © 2012 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Increasing On-Task Behavior through Motivational Activities

ERIC Educational Resources Information Center

Lantz, Christine; McKenna, Barbara; Price, Brianne; Stralow, Duane

2007-01-01

This report describes a program designed to increase students' on-task behavior. The students in the sample population consisted of kindergarten, first, and fifth graders. These classrooms are located in a community in northern Illinois. The problem of student behavior adversely affecting on-task behavior was well documented through a review of…

Life Sciences Research Facility automation requirements and concepts for the Space Station

NASA Technical Reports Server (NTRS)

Rasmussen, Daryl N.

1986-01-01

An evaluation is made of the methods and preliminary results of a study on prospects for the automation of the NASA Space Station's Life Sciences Research Facility. In order to remain within current Space Station resource allocations, approximately 85 percent of planned life science experiment tasks must be automated; these tasks encompass specimen care and feeding, cage and instrument cleaning, data acquisition and control, sample analysis, waste management, instrument calibration, materials inventory and management, and janitorial work. Task automation will free crews for specimen manipulation, tissue sampling, data interpretation and communication with ground controllers, and experiment management.

An occupational exposure assessment for engineered nanoparticles used in semiconductor fabrication.

PubMed

Shepard, Michele Noble; Brenner, Sara

2014-03-01

Engineered nanoparticles of alumina, amorphous silica, and ceria are used in semiconductor device fabrication during wafer polishing steps referred to as 'chemical mechanical planarization' (CMP). Some metal oxide nanoparticles can impact the biological response of cells and organ systems and may cause adverse health effects; additional research is necessary to better understand potential risks from nanomaterial applications and occupational exposure scenarios. This study was conducted to assess potential airborne exposures to nanoparticles and agglomerates using direct-reading instruments and filter-based samples to characterize workplace aerosols by particle number, mass, size, composition, and morphology. Sampling was repeated for tasks in three work areas (fab, subfab, wastewater treatment) at a facility using engineered nanoparticles for CMP. Real-time measurements were collected using a condensation particle counter (CPC), optical particle counter, and scanning mobility particle spectrometer (SMPS). Filter-based samples were analyzed for total mass or the respirable fraction, and for specific metals of interest. Additional air sample filters were analyzed by transmission electron microscopy with energy dispersive x-ray spectroscopy (TEM/EDX) for elemental identification and to provide data on particle size, morphology, and concentration. Peak concentrations measured on the CPC ranged from 1 to 16 particles per cubic centimeter (P cm(-3)) for background and from 4 to 74 P cm(-3) during tasks sampled in the fab; from 1 to 60 P cm(-3) for background and from 3 to 84 P cm(-3) for tasks sampled in the subfab; and from 1160 to 45 894 P cm(-3) for background and from 1710 to 45 519 P cm(-3) during wastewater treatment system filter change tasks. Significant variability was seen among the repeated task measurements and among background comparisons in each area. Several data analysis methods were used to compare each set of task and background measurements. Increased concentrations of respirable particles were identified for some tasks sampled in each work area, although of relatively low magnitude and inconsistently among repeated measurements for specific tasks. Measurements with a portable SMPS indicated that nanoparticle number concentrations (channels 11.5-115.5nm) increased above background levels by 3.2 P cm(-3) during CMP tool set-up in the fab area but were not elevated when changing filters for the CMP wastewater treatment system. All results from mass concentration analysis were below the limits of detection. Characterization by TEM/EDX identified structures containing the elements of interest (Al, Si), primarily as agglomerates or aggregates in the 100-1000nm size range. Although health-based occupational exposure limits have not been established for nanoscale alumina, silica, or ceria, the measured concentrations by number and mass were below currently proposed benchmarks or reference values for poorly soluble low-toxicity nanoparticles.

Understanding self-reported difficulties in decision-making by people with autism spectrum disorders.

PubMed

Vella, Lydia; Ring, Howard A; Aitken, Mike Rf; Watson, Peter C; Presland, Alexander; Clare, Isabel Ch

2017-04-01

Autobiographical accounts and a limited research literature suggest that adults with autism spectrum disorders can experience difficulties with decision-making. We examined whether some of the difficulties they describe correspond to quantifiable differences in decision-making when compared to adults in the general population. The participants (38 intellectually able adults with autism spectrum disorders and 40 neurotypical adults) were assessed on three tasks of decision-making (Iowa Gambling Task, Cambridge Gamble Task and Information Sampling Task), which quantified, respectively, decision-making performance and relative attention to negative and positive outcomes, speed and flexibility, and information sampling. As a caution, all analyses were repeated with a subset of participants ( n ASD  = 29 and n neurotypical  = 39) who were not taking antidepressant or anxiolytic medication. Compared to the neurotypical participants, participants with autism spectrum disorders demonstrated slower decision-making on the Cambridge Gamble Task, and superior performance on the Iowa Gambling Task. When those taking the medications were excluded, participants with autism spectrum disorders also sampled more information. There were no other differences between the groups. These processing tendencies may contribute to the difficulties self-reported in some contexts; however, the results also highlight strengths in autism spectrum disorders, such as a more logical approach to, and care in, decision-making. The findings lead to recommendations for how adults with autism spectrum disorders may be better supported with decision-making.

Gender differences in brain activation on a mental rotation task.

PubMed

Semrud-Clikeman, Margaret; Fine, Jodene Goldenring; Bledsoe, Jesse; Zhu, David C

2012-10-01

Few neuroimaging studies have explored gender differences on mental rotation tasks. Most studies have utilized samples with both genders, samples mainly consisting of men, or samples with six or fewer females. Graduate students in science fields or liberal arts programs (20 males, 20 females) completed a mental rotation task during functional magnetic resonance imaging (fMRI). When a pair of cube figures was shown, the participant made a keypad response based on whether the pair is the same/similar or different. Regardless of gender, the bilateral middle frontal gyrus, bilateral intraparietal sulcus (IPS), and the left precuneus were activated when a subject tried to solve the mental rotation task. Increased activation in the right inferior frontal gyrus/middle frontal gyrus, the left precuneus/posterior cingulate cortex/cuneus region, and the left middle occipital gyrus was found for men as compared to women. Better accuracy and shorter response times were correlated with an increased activation in the bilateral intraparietal sulcus. No significant brain activity differences related to mental rotation were found between academic majors. These findings suggest that networks involved in visual attention appear to be more strongly activated in the mental rotation tasks in men as compared to women. It also suggests that men use a more automatic process when analyzing complex visual reasoning tasks while women use a more top-down process.

Students' Perceptions of a Self-Diagnosis Task

NASA Astrophysics Data System (ADS)

Safadi, Rafi'; Yerushalmi, Edit

2009-11-01

What happens when students are required to engage in a self-diagnosis task; in other words get time and credit for identifying mistakes they made assisted by a sample solution? We examine this question using data collected on 180 high school students in the Arab sector in Israel. Students were able to find significant differences between their solutions and the sample solution. Yet many did not provide self-explanations indicating that they acknowledged a conflict between their mental models and the scientific model. Further, students also addressed non-significant differences. They apparently referred to the sample solution as an ultimate template and identified external deviations from it as flaws or weaknesses. Students reflected on their personal solution process, and the materials used in the task. The findings suggest allocating time for scaffolding "self-diagnosis."

Learning Strategies in Matching to Sample: If-then and Configural Learning by Pigeons

PubMed Central

Katz, Jeffrey S.; Bodily, Kent D.; Wright, Anthony A.

2008-01-01

Pigeons learned a matching-to-sample task with a split training-set design in which half of the stimulus displays were untrained and tested following acquisition. Transfer to the untrained displays along with no novel-stimulus transfer indicated that these pigeons learned the task (partially) via if-then rules. Comparisons to other performance measures indicated that they also partially learned the task via configural learning (learning the gestalt of the whole stimulus display). Differences in the FR-sample requirement (1 vs. 20) had no systematic effect on the type of learning or level of learning obtained. Differences from a previous study (Wright, 1997) are discussed, including the effect of displaying the stimuli vertically (traditional display orientation) or horizontally from the floor. PMID:18079071

Expectancy-value theory in persistence of learning effects in schizophrenia: role of task value and perceived competency.

PubMed

Choi, Jimmy; Fiszdon, Joanna M; Medalia, Alice

2010-09-01

Expectancy-value theory, a widely accepted model of motivation, posits that expectations of success on a learning task and the individual value placed on the task are central determinants of motivation to learn. This is supported by research in healthy controls suggesting that beliefs of self-and-content mastery can be so influential they can predict the degree of improvement on challenging cognitive tasks even more so than general cognitive ability. We examined components of expectancy-value theory (perceived competency and task value), along with baseline arithmetic performance and neuropsychological performance, as possible predictors of learning outcome in a sample of 70 outpatients with schizophrenia randomized to 1 of 2 different arithmetic learning conditions and followed up after 3 months. Results indicated that as with nonpsychiatric samples, perceived self-competency for the learning task was significantly related to perceptions of task value attributed to the learning task. Baseline expectations of success predicted persistence of learning on the task at 3-month follow-up, even after accounting for variance attributable to different arithmetic instruction, baseline arithmetic ability, attention, and self-reports of task interest and task value. We also found that expectation of success is a malleable construct, with posttraining improvements persisting at follow-up. These findings support the notion that expectancy-value theory is operative in schizophrenia. Thus, similar to the nonpsychiatric population, treatment benefits may be enhanced and better maintained if remediation programs also focus on perceptions of self-competency for the training tasks. Treatment issues related to instilling self-efficacy in cognitive recovery programs are discussed.

Do Right- and Left-Handed Monkeys Differ on Cognitive Measures?

NASA Technical Reports Server (NTRS)

Hopkins, William D.; Washburn, David A.

1994-01-01

Twelve left- and 14 right-handed monkeys were compared on 6 measures of cognitive performance (2 maze-solving tasks, matching-to-sample, delayed matching-to-sample, delayed response using spatial cues, and delayed response using form cues). The dependent variable was trials-to-training criterion for each of the 6 tasks. Significant differences were found between left- and right-handed monkeys on the 2 versions of the delayed response task. Right-handed monkeys reached criterion significantly faster on the form cue version of the task, whereas left-handed monkeys reached criterion significantly faster on delayed response for spatial position (p less than .05). The results suggest that sensitive hand preference measures of laterality can reveal differences in cognitive performance, which in turn may reflect underlying laterality in functional organization of the nervous system.

SOAR: An Architecture for General Intelligence

DTIC Science & Technology

1987-12-01

these tasks, and (3) learn about all aspects of the tasks and its performance on them. Soar has existed since mid 1982 as an experimental software system...intelligence. Soar’s behavior has already been studied over a range of tasks and methods (Figure 1), which sample its intended range, though...in multiple small tasks: Generate and test, AND/OR search, hill climbing ( simple and steepest-ascent), means-ends analysis, operator subgoaling

Is the hand to speech what speech is to the hand?

PubMed

Mildner, V

2000-01-01

Interference between the manual and the verbal performance on two types of concurrent verbal-manual tasks was studied on a sample of 48 female right-handers. The more complex verbal task (storytelling) affected both hands significantly, the less complex (essentially phonemic) task affected only the right hand, with insignificant negative influence on the left-hand performance. No significant reciprocal effects of the motor task on verbalization were found.

Influence of Ongoing Task Difficulty and Motivation Level on Children's Prospective Memory in a Chinese Sample.

PubMed

Han, Pi-Guo; Han, Lei; Bian, Yu-Long; Tian, Yu; Xu, Min-Xia; Gao, Feng-Qiang

2017-01-01

Prospective memory (PM) is the process associated with the task of realizing delayed intentions in the future. Researchers distinguish two types of PM, namely time-based PM (tbPM) and event-based PM (ebPM). Experiment 1 investigated the developmental trajectory of 3- to 5-year-old preschool children's PM ability, and the occurrence of delayed retrieval (children execute the PM task in a larger window of opportunity) in both tbPM and ebPM tasks. Results revealed that the 5-year-old children outperformed the 3- and 4-year-old children in PM. Moreover, delayed retrieval was more likely to occur in tbPM task than in ebPM task. In Experiment 2, the influence of ongoing task (OT) difficulty on PM performance was investigated with a sample of 5-year-old children. Results revealed no significant effect of OT difficulty on PM performance. In Experiment 3, we improved children's motivation level to complete the OT, then explored the influence of OT difficulty on children's PM performance. Results revealed that the effect of OT difficulty on PM performance became significant after increasing the children's motivation to complete the OT. These results provide insights into the mechanism of attentional resource allocation in PM tasks and have crucial educational and social implications.

Performance of Brazilian children on phonemic and semantic verbal fluency tasks

PubMed Central

Charchat-Fichman, Helenice; Oliveira, Rosinda Martins; da Silva, Andreza Morais

2011-01-01

The most used verbal fluency paradigms are semantic and letter fluency tasks. Studies suggest that these paradigms access semantic memory and executive function and are sensitive to frontal lobe disturbances. There are few studies in Brazilian samples on these paradigms. Objective The present study investigated performance, and the effects of age, on verbal fluency tasks in Brazilian children. The results were compared with those of other studies, and the consistency of the scoring criteria data is presented. Methods A sample of 119 children (7 to 10 years old) was submitted to the three phonemic fluency (F, A, M) tasks and three semantic fluency (animals, clothes, fruits) tasks. The results of thirty subjects were scored by two independent examiners. Results A significant positive correlation was found between the scores calculated by the two independent examiners. Significant positive correlations were found between performance on the semantic fluency task and the phonemic fluency task. The effect of age was significant for both tasks, and a significant difference was found between the 7- and 9-year-old subjects and between the 7- and 10-year-old subjects. The 8-year-old group did not differ to any of the other age groups. Conclusion The pattern of results was similar to that observed in previous Brazilian and international studies. PMID:29213727

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

Stormont, John; Lampe, Brandon; Mills, Melissa

The goal of this project is to improve the understanding of key aspects of the coupled thermal-mechanical-hydrologic response of granular (or crushed) salt used as a seal material for shafts, drifts, and boreholes in mined repositories in salt. The project is organized into three tasks to accomplish this goal: laboratory measurements of granular salt consolidation (Task 1), microstructural observations on consolidated samples (Task 2), and constitutive model development and evaluation (Task 3). Task 1 involves laboratory measurements of salt consolidation along with thermal properties and permeability measurements conducted under a range of temperatures and stresses expected for potential mined repositoriesmore » in salt. Testing focused on the role of moisture, temperature and stress state on the hydrologic (permeability) and thermal properties of consolidating granular salt at high fractional densities. Task 2 consists of microstructural observations made on samples after they have been consolidated to interpret deformation mechanisms and evaluate the ability of the constitutive model to predict operative mechanisms under different conditions. Task 3 concerns the development of the coupled thermal-mechanical-hydrologic constitutive model for granular salt consolidation. The measurements and observations in Tasks 1 and 2 were used to develop a thermal-mechanical constitutive model. Accomplishments and status from each of these efforts is reported in subsequent sections of this report« less

Cognitive tasks promote automatization of postural control in young and older adults.

PubMed

Potvin-Desrochers, Alexandra; Richer, Natalie; Lajoie, Yves

2017-09-01

Researchers looking at the effects of performing a concurrent cognitive task on postural control in young and older adults using traditional center-of-pressure measures and complexity measures found discordant results. Results of experiments showing improvements of stability have suggested the use of strategies such as automatization of postural control or stiffening strategy. This experiment aimed to confirm in healthy young and older adults that performing a cognitive task while standing leads to improvements that are due to automaticity of sway by using sample entropy. Twenty-one young adults and twenty-five older adults were asked to stand on a force platform while performing a cognitive task. There were four cognitive tasks: simple reaction time, go/no-go reaction time, equation and occurrence of a digit in a number sequence. Results demonstrated decreased sway area and variability as well as increased sample entropy for both groups when performing a cognitive task. Results suggest that performing a concurrent cognitive task promotes the adoption of an automatic postural control in young and older adults as evidenced by an increased postural stability and postural sway complexity. Copyright © 2017 Elsevier B.V. All rights reserved.

Assessing abuse risk beyond self-report: analog task of acceptability of parent-child aggression.

PubMed

Rodriguez, Christina M; Russa, Mary Bower; Harmon, Nancy

2011-03-01

The present investigation reports on the development and initial validation of a new analog task, the Parent-Child Aggression Acceptability Movie Task (P-CAAM), intended to assess respondents' acceptance of parent-child aggression, including both physical discipline and physical abuse. Two independent samples were utilized to develop and evaluate the P-CAAM: an undergraduate sample to initially pilot the task and a separate sample of normative parents for additional assessment of validity. Scores from the P-CAAM were compared to related measures, including measures of self-reported disciplinary attitudes, child abuse potential, harsh parenting style, and use and escalation of physical discipline practices on another analog parenting task. Across the studies, the P-CAAM demonstrated acceptable internal consistency and construct validity, evidencing mild to moderate associations with both self-report and analog measures. Participants demonstrating increased acceptance of physical discipline and physical abuse on the P-CAAM analog task also reported greater approval of physical discipline, greater use of and escalation of physical discipline, harsher parenting styles, and higher child abuse potential on two separate measures. The P-CAAM analog appears to offer a promising alternative and/or supplement to conventional self-report measures, assessing attitudes regarding the acceptability of parent-child aggression in a way that is less likely to be influenced by social desirability. Suggestions for future evaluations with alternative samples, as well as possible implications of the data for disciplinary reactions are discussed. The development of alternatives to self-report measurement may lead to clarification of theoretical models of abuse in ways that lead to improvements in intervention programming; analogs may also provide a useful means to assess intervention programming outcomes. Copyright © 2011 Elsevier Ltd. All rights reserved.

Examining Infants' Cortisol Responses to Laboratory Tasks among Children Varying in Attachment Disorganization: Stress Reactivity or Return to Baseline?

ERIC Educational Resources Information Center

Bernard, Kristin; Dozier, Mary

2010-01-01

Cortisol is a hormone involved in mounting a stress response in humans. The evidence of stress reactivity among young children has been mixed, however. In the present study, the order of two laboratory tasks (i.e., Strange Situation and play) was counterbalanced, and home saliva samples were obtained. Saliva samples were also collected upon the…

The Relationship between Theory of Mind and Executive Function in a Sample of Children from Mainland China

ERIC Educational Resources Information Center

Yang, Juan; Zhou, Shijie; Yao, Shuqiao; Su, Linyan; McWhinnie, Chad

2009-01-01

To explore the relationship between theory of mind (ToM) and executive function (EF) in a sample of individuals from mainland China, 20 children with autism spectrum disorders (ASD), 26 children with Attention Deficit Hyperactivity Disorder (ADHD), and 30 normal control subjects were compared on two batteries of ToM tasks and EF tasks. Children…

The effects of task difficulty, novelty and the size of the search space on intrinsically motivated exploration.

PubMed

Baranes, Adrien F; Oudeyer, Pierre-Yves; Gottlieb, Jacqueline

2014-01-01

Devising efficient strategies for exploration in large open-ended spaces is one of the most difficult computational problems of intelligent organisms. Because the available rewards are ambiguous or unknown during the exploratory phase, subjects must act in intrinsically motivated fashion. However, a vast majority of behavioral and neural studies to date have focused on decision making in reward-based tasks, and the rules guiding intrinsically motivated exploration remain largely unknown. To examine this question we developed a paradigm for systematically testing the choices of human observers in a free play context. Adult subjects played a series of short computer games of variable difficulty, and freely choose which game they wished to sample without external guidance or physical rewards. Subjects performed the task in three distinct conditions where they sampled from a small or a large choice set (7 vs. 64 possible levels of difficulty), and where they did or did not have the possibility to sample new games at a constant level of difficulty. We show that despite the absence of external constraints, the subjects spontaneously adopted a structured exploration strategy whereby they (1) started with easier games and progressed to more difficult games, (2) sampled the entire choice set including extremely difficult games that could not be learnt, (3) repeated moderately and high difficulty games much more frequently than was predicted by chance, and (4) had higher repetition rates and chose higher speeds if they could generate new sequences at a constant level of difficulty. The results suggest that intrinsically motivated exploration is shaped by several factors including task difficulty, novelty and the size of the choice set, and these come into play to serve two internal goals-maximize the subjects' knowledge of the available tasks (exploring the limits of the task set), and maximize their competence (performance and skills) across the task set.

New evidence in theory of mind deficits in subjects with chronic schizophrenia and first episode: correlation with symptoms, neurocognition and social function.

PubMed

Mazza, Monica; Pollice, Rocco; Pacitti, Francesca; Pino, Maria Chiara; Mariano, Melania; Tripaldi, Simona; Casacchia, Massimo; Roncone, Rita

2012-01-01

Currently substantial evidence exists about Theory of Mind (ToM) impairment in subjects affected by chronic and first episode schizophrenia. In particular, in order to enhance the validity of our construct, we used in this study classical false beliefs tasks and advanced theory of mind tasks, together with the application of structural equation model, in order to ex-amine whether we are using ToM tasks with good psychometric properties. The main goal of the present study was to examine ToM deficits in a large sample including subjects suffering from chronic schizophrenia, first episode of schizophrenia and nor-mal controls, by observing in the same task the relationship with symptomatological gravity, neurocognition and social function.Materials and methods. A sample of 178 patients with chronic schizophrenia, a sample of 49 subjects with a first episode of psychosis and 484 healthy controls participated to this study. Measures of social cognition included task of false belief and advanced theory of mind task. No significant differences were found on ToM tasks between subjects affected by chronic and first episode schizophrenia. Social cognition showed in both groups a strong correlation with negative symptoms and social function, but did not evidence any relationship with neurocognition. CONCLUSION; ToM deficits exist in subjects suffering from chronic and first episode schizophrenia. These impairments do not seem to be a consequence of illness condition, they are likely to be state-independent and appear to be the most important cognitive mediator of social functioning in both groups.

Assessing Abuse Risk beyond Self-Report: Analog Task of Acceptability of Parent-Child Aggression

ERIC Educational Resources Information Center

Rodriguez, Christina M.; Russa, Mary Bower; Harmon, Nancy

2011-01-01

Objectives: The present investigation reports on the development and initial validation of a new analog task, the Parent-Child Aggression Acceptability Movie Task (P-CAAM), intended to assess respondents' acceptance of parent-child aggression, including both physical discipline and physical abuse. Methods: Two independent samples were utilized to…

Task-Contingent Conscientiousness as a Unit of Personality at Work

ERIC Educational Resources Information Center

Minbashian, Amirali; Wood, Robert E.; Beckmann, Nadin

2010-01-01

The present study examined the viability of incorporating task-contingent units into the study of personality at work, using conscientiousness as an illustrative example. We used experience-sampling data from 123 managers to show that (a) momentary conscientiousness at work is contingent on the difficulty and urgency demands of the tasks people…

Language Helps Children Succeed on a Classic Analogy Task

ERIC Educational Resources Information Center

Christie, Stella; Gentner, Dedre

2014-01-01

Adult humans show exceptional relational ability relative to other species. In this research, we trace the development of this ability in young children. We used a task widely used in comparative research--the relational match-to-sample task, which requires participants to notice and match the identity relation: for example, AA should match BB…

Children's Task Oriented Patterns in Early Childhood: A Latent Transition Analysis

ERIC Educational Resources Information Center

Wang, Feihong; Algina, James; Snyder, Patricia; Cox, Martha; Vernon-Feagans, Lynne; Cox, Martha; Blair, Clancy; Burchinal, Margaret; Burton, Linda; Crnic, Keith; Crouter, Ann; Garrett-Peters, Patricia; Greenberg, Mark; Lanza, Stephanie; Mills-Koonce, Roger; Werner, Emily; Willoughby, Michael

2017-01-01

We examined individual differences and predictions of children's patterns in behavioral, emotional and attentional efforts toward challenging puzzle tasks at 24 and 35 months using data from a large longitudinal rural representative sample. Using latent transition analysis, we found four distinct task-oriented patterns in problem-solving tasks…

Exploring the Black Box: An Analysis of Work Group Diversity, Conflict, and Performance.

ERIC Educational Resources Information Center

Pelled, Lisa Hope; Eisenhardt, Kathleen M.; Xin, Katherine R.

1999-01-01

Tests an integrative model of the relationships among diversity, conflict, and performance, using a sample of 45 electronics-industry worker teams. Functional background diversity drives task conflict; multiple types of diversity drive emotional conflict. Task conflict affects task performance more favorably than does emotional conflict. (102…

A target sample of adolescents and reward processing: same neural and behavioral correlates engaged in common paradigms?

PubMed

Nees, Frauke; Vollstädt-Klein, Sabine; Fauth-Bühler, Mira; Steiner, Sabina; Mann, Karl; Poustka, Luise; Banaschewski, Tobias; Büchel, Christian; Conrod, Patricia J; Garavan, Hugh; Heinz, Andreas; Ittermann, Bernd; Artiges, Eric; Paus, Tomas; Pausova, Zdenka; Rietschel, Marcella; Smolka, Michael N; Struve, Maren; Loth, Eva; Schumann, Gunter; Flor, Herta

2012-11-01

Adolescence is a transition period that is assumed to be characterized by increased sensitivity to reward. While there is growing research on reward processing in adolescents, investigations into the engagement of brain regions under different reward-related conditions in one sample of healthy adolescents, especially in a target age group, are missing. We aimed to identify brain regions preferentially activated in a reaction time task (monetary incentive delay (MID) task) and a simple guessing task (SGT) in a sample of 14-year-old adolescents (N = 54) using two commonly used reward paradigms. Functional magnetic resonance imaging was employed during the MID with big versus small versus no win conditions and the SGT with big versus small win and big versus small loss conditions. Analyses focused on changes in blood oxygen level-dependent contrasts during reward and punishment processing in anticipation and feedback phases. We found clear magnitude-sensitive response in reward-related brain regions such as the ventral striatum during anticipation in the MID task, but not in the SGT. This was also true for reaction times. The feedback phase showed clear reward-related, but magnitude-independent, response patterns, for example in the anterior cingulate cortex, in both tasks. Our findings highlight neural and behavioral response patterns engaged in two different reward paradigms in one sample of 14-year-old healthy adolescents and might be important for reference in future studies investigating reward and punishment processing in a target age group.

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

The silver lining of a mind in the clouds: interesting musings are associated with positive mood while mind-wandering

PubMed Central

Franklin, Michael S.; Mrazek, Michael D.; Anderson, Craig L.; Smallwood, Jonathan; Kingstone, Alan; Schooler, Jonathan W.

2013-01-01

The negative effects of mind-wandering on performance and mood have been widely documented. In a recent well-cited study, Killingsworth and Gilbert (2010) conducted a large experience sampling study revealing that all off-task episodes, regardless of content, have equal to or lower happiness ratings, than on-task episodes. We present data from a similarly implemented experience sampling study with additional mind-wandering content categories. Our results largely conform to those of the Killingsworth and Gilbert (2010) study, with mind-wandering generally being associated with a more negative mood. However, subsequent analyses reveal situations in which a more positive mood is reported after being off-task. Specifically when off-task episodes are rated for interest, the high interest episodes are associated with an increase in positive mood compared to all on-task episodes. These findings both identify a situation in which mind-wandering may have positive effects on mood, and suggest the possible benefits of encouraging individuals to shift their off-task musings to the topics they find most engaging. PMID:24009599

Exposure assessment using human biomonitoring for glyphosate and fluroxypyr users in amenity horticulture.

PubMed

Connolly, Alison; Jones, Kate; Galea, Karen S; Basinas, Ioannis; Kenny, Laura; McGowan, Padraic; Coggins, Marie

2017-08-01

Pesticides and their potential adverse health effects are of great concern and there is a dearth of knowledge regarding occupational exposure to pesticides among amenity horticulturalists. This study aims to measure occupational exposures to amenity horticuturalists using pesticides containing the active ingredients, glyphosate and fluroxypyr by urinary biomonitoring. A total of 40 work tasks involving glyphosate and fluroxypyr were surveyed over the period of June - October 2015. Workers used a variety of pesticide application methods; manual knapsack sprayers, controlled droplet applicators, pressurised lance applicators and boom sprayers. Pesticide concentrations were measured in urine samples collected pre and post work tasks using liquid chromatography tandem mass spectrometry (LC-MS/MS). Differences in pesticide urinary concentrations pre and post work task, and across applications methods were analysed using paired t-tests and linear regression. Pesticide urinary concentrations were higher than those reported for environmental exposures and comparable to those reported in some agricultural studies. Log-transformed pesticide concentrations were statistically significantly higher in post-work samples compared to those in pre-work samples (paired t-test, p<0.001; for both μgL -1 and μmol/mol creatinine). Urinary pesticide concentrations in post-work samples had a geometric mean (geometric standard deviation) of 0.66 (1.11) μgL -1 for glyphosate and 0.29 (1.69) μgL -1 for fluroxypyr. Linear regression revealed a statistically significant positive association to exist between the time-interval between samples and the log-transformed adjusted (i.e. post- minus pre-task) pesticide urinary concentrations (β=0.0039; p<0.0001). Amenity horticulturists can be exposed to pesticides during tasks involving these products. Further research is required to evaluate routes of exposure among this occupational group. Crown Copyright © 2017. Published by Elsevier GmbH. All rights reserved.

Identification of the Properties of Gum Arabic Used as a Binder in 7.62-mm Ammunition Primers

DTIC Science & Technology

2010-06-01

Solution - LCC Testing (ATK Task 700) 51 Cartridge - Ballistic Testing (ATK Task 800) 51 ATK Elemental Analysis 52 Moisture Loss and Friability...Hummel sample 7 3 SDT summary for Quadra sample 8 4 Particle size analysis summary for gum arabic samples 9 5 SEM images of Colony gum arabic at 230x...strengths 21 16 Color analysis : Colony after 5.0 hrs 23 17 Color analysis : Hummel after 5.0 hrs 23 18 Color analysis : Brenntag after 5.0 hrs 23 19 Gel

A Dictionary Learning Approach for Signal Sampling in Task-Based fMRI for Reduction of Big Data

PubMed Central

Ge, Bao; Li, Xiang; Jiang, Xi; Sun, Yifei; Liu, Tianming

2018-01-01

The exponential growth of fMRI big data offers researchers an unprecedented opportunity to explore functional brain networks. However, this opportunity has not been fully explored yet due to the lack of effective and efficient tools for handling such fMRI big data. One major challenge is that computing capabilities still lag behind the growth of large-scale fMRI databases, e.g., it takes many days to perform dictionary learning and sparse coding of whole-brain fMRI data for an fMRI database of average size. Therefore, how to reduce the data size but without losing important information becomes a more and more pressing issue. To address this problem, we propose a signal sampling approach for significant fMRI data reduction before performing structurally-guided dictionary learning and sparse coding of whole brain's fMRI data. We compared the proposed structurally guided sampling method with no sampling, random sampling and uniform sampling schemes, and experiments on the Human Connectome Project (HCP) task fMRI data demonstrated that the proposed method can achieve more than 15 times speed-up without sacrificing the accuracy in identifying task-evoked functional brain networks. PMID:29706880

A Dictionary Learning Approach for Signal Sampling in Task-Based fMRI for Reduction of Big Data.

PubMed

Ge, Bao; Li, Xiang; Jiang, Xi; Sun, Yifei; Liu, Tianming

2018-01-01

The exponential growth of fMRI big data offers researchers an unprecedented opportunity to explore functional brain networks. However, this opportunity has not been fully explored yet due to the lack of effective and efficient tools for handling such fMRI big data. One major challenge is that computing capabilities still lag behind the growth of large-scale fMRI databases, e.g., it takes many days to perform dictionary learning and sparse coding of whole-brain fMRI data for an fMRI database of average size. Therefore, how to reduce the data size but without losing important information becomes a more and more pressing issue. To address this problem, we propose a signal sampling approach for significant fMRI data reduction before performing structurally-guided dictionary learning and sparse coding of whole brain's fMRI data. We compared the proposed structurally guided sampling method with no sampling, random sampling and uniform sampling schemes, and experiments on the Human Connectome Project (HCP) task fMRI data demonstrated that the proposed method can achieve more than 15 times speed-up without sacrificing the accuracy in identifying task-evoked functional brain networks.

Stability of handwriting performance following injury-induced hand-dominance transfer in adults: a pilot study.

PubMed

Yancosek, Kathleen E; Mullineaux, David R

2011-01-01

The aim of this study was to quantify stability of nondominant handwriting kinematics and legibility in participants with functional loss of the previously dominant hand. Twelve adult volunteers provided two handwriting samples 6 weeks apart. Handwriting tasks (Compose a Sentence, Copy Alphabet, Copy Date, Copy Sentence, and Draw Circles) were performed in cursive writing on standard white, lined paper taped to a digitizer to record kinematic and kinetic variables of velocity, displacement, force, and on-paper time. Results showed minimal performance variability within subjects and marked variability between subjects, as well as variability between tasks for all participants. Stylistic stability of the handwriting samples was assessed by two independent evaluators. These evaluators matched all handwriting samples at test to retest times with 89%-100% accuracy, suggesting value in the "whole" handwriting sample and emphasizing the idiosyncratic nature of handwriting. Results suggest that handwriting skill stability in the previously nondominant hand varies across subjects and task demands.

Prediction task guided representation learning of medical codes in EHR.

PubMed

Cui, Liwen; Xie, Xiaolei; Shen, Zuojun

2018-06-18

There have been rapidly growing applications using machine learning models for predictive analytics in Electronic Health Records (EHR) to improve the quality of hospital services and the efficiency of healthcare resource utilization. A fundamental and crucial step in developing such models is to convert medical codes in EHR to feature vectors. These medical codes are used to represent diagnoses or procedures. Their vector representations have a tremendous impact on the performance of machine learning models. Recently, some researchers have utilized representation learning methods from Natural Language Processing (NLP) to learn vector representations of medical codes. However, most previous approaches are unsupervised, i.e. the generation of medical code vectors is independent from prediction tasks. Thus, the obtained feature vectors may be inappropriate for a specific prediction task. Moreover, unsupervised methods often require a lot of samples to obtain reliable results, but most practical problems have very limited patient samples. In this paper, we develop a new method called Prediction Task Guided Health Record Aggregation (PTGHRA), which aggregates health records guided by prediction tasks, to construct training corpus for various representation learning models. Compared with unsupervised approaches, representation learning models integrated with PTGHRA yield a significant improvement in predictive capability of generated medical code vectors, especially for limited training samples. Copyright © 2018. Published by Elsevier Inc.

INAPPROPRIATE CONFIDENCE AND RETIREMENT PLANNING: FOUR STUDIES WITH A NATIONAL SAMPLE

PubMed Central

Parker, Andrew M.; de Bruin, Wändi Bruine; Yoong, Joanne; Willis, Robert

2011-01-01

Financial decisions about investing and saving for retirement are increasingly complex, requiring financial knowledge and confidence in that knowledge. Few studies have examined whether direct assessments of individuals’ confidence are related to the outcomes of their financial decisions. Here, we analyzed data from a national sample recruited through RAND’s American Life Panel (ALP), an internet panel of U.S. adults aged 18 to 88. We examined the relationship of confidence with self-reported and actual financial decisions, using four different tasks, each performed by overlapping samples of ALP participants. The four tasks were designed by different researchers for different purposes, using different methods to assess confidence. Yet, measures of confidence were correlated across tasks, and results were consistent across methodologies. Confidence and knowledge showed only modest positive correlations. However, even after controlling for actual knowledge, individuals with greater confidence were more likely to report financial planning for retirement and to successfully minimize fees on a hypothetical investment task. Implications for the role of confidence (even if it is unjustified) in investment behavior is discussed. PMID:23049164

The awakening of the attention: Evidence for a link between the monitoring of mind wandering and prospective goals.

PubMed

Seli, Paul; Smilek, Daniel; Ralph, Brandon C W; Schacter, Daniel L

2018-03-01

Across 2 independent samples, we examined the relation between individual differences in rates of self-caught mind wandering and individual differences in temporal monitoring of an unrelated response goal. Rates of self-caught mind wandering were assessed during a commonly used sustained-attention task, and temporal goal monitoring was indexed during a well-established prospective-memory task. The results from both samples showed a positive relation between rates of self-caught mind wandering during the sustained-attention task and rates of checking a clock to monitor the amount of time remaining before a response was required in the prospective-memory task. This relation held even when controlling for overall propensity to mind-wander (indexed by intermittent thought probes) and levels of motivation (indexed by subjective reports). These results suggest the possibility that there is a common monitoring system that monitors the contents of consciousness and the progress of ongoing goals and tasks. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Integration and segregation of large-scale brain networks during short-term task automatization

PubMed Central

Mohr, Holger; Wolfensteller, Uta; Betzel, Richard F.; Mišić, Bratislav; Sporns, Olaf; Richiardi, Jonas; Ruge, Hannes

2016-01-01

The human brain is organized into large-scale functional networks that can flexibly reconfigure their connectivity patterns, supporting both rapid adaptive control and long-term learning processes. However, it has remained unclear how short-term network dynamics support the rapid transformation of instructions into fluent behaviour. Comparing fMRI data of a learning sample (N=70) with a control sample (N=67), we find that increasingly efficient task processing during short-term practice is associated with a reorganization of large-scale network interactions. Practice-related efficiency gains are facilitated by enhanced coupling between the cingulo-opercular network and the dorsal attention network. Simultaneously, short-term task automatization is accompanied by decreasing activation of the fronto-parietal network, indicating a release of high-level cognitive control, and a segregation of the default mode network from task-related networks. These findings suggest that short-term task automatization is enabled by the brain's ability to rapidly reconfigure its large-scale network organization involving complementary integration and segregation processes. PMID:27808095

Gamma and Beta Oscillations Define a Sequence of Neurocognitive Modes Present in Odor Processing

PubMed Central

Frederick, Donald E.; Brown, Austin; Brim, Elizabeth; Mehta, Nisarg; Vujovic, Mark

2016-01-01

Olfactory system beta (15–35 Hz) and gamma (40–110 Hz) oscillations of the local field potential in mammals have both been linked to odor learning and discrimination. Gamma oscillations represent the activity of a local network within the olfactory bulb, and beta oscillations represent engagement of a systemwide network. Here, we test whether beta and gamma oscillations represent different cognitive modes using the different demands of go/no-go and two-alternative choice tasks that previously were suggested to favor beta or gamma oscillations, respectively. We reconcile previous studies and show that both beta and gamma oscillations occur in both tasks, with gamma dominating the early odor sampling period (2–4 sniffs) and beta dominating later. The relative power and coherence of both oscillations depend separately on multiple factors within both tasks without categorical differences across tasks. While the early/gamma-associated period occurs in all trials, rats can perform above chance without the later/beta-associated period. Longer sampling, which includes beta oscillations, is associated with better performance. Gamma followed by beta oscillations therefore represents a sequence of cognitive and neural states during odor discrimination, which can be separately modified depending on the demands of a task and odor discrimination. Additionally, fast (85 Hz) and slow (70 Hz) olfactory bulb gamma oscillation sub-bands have been hypothesized to represent tufted and mitral cell networks, respectively (Manabe and Mori, 2013). We find that fast gamma favors the early and slow gamma the later (beta-dominated) odor-sampling period and that the relative contributions of these oscillations are consistent across tasks. SIGNIFICANCE STATEMENT Olfactory system gamma (40–110 Hz) and beta (15–35 Hz) oscillations of the local field potential indicate different neural firing statistics and functional circuits. We show that gamma and beta oscillations occur in stereotyped sequence during odor sampling in associative tasks, with local gamma dominating the first 250 ms of odor sniffing, followed by systemwide beta as behavioral responses are prepared. Oscillations and coupling strength between brain regions are modulated by task, odor, and learning, showing that task features can dramatically adjust the dynamics of a cortical sensory system, which changes state every ∼250 ms. Understanding cortical circuits, even at the biophysical level, depends on careful use of multiple behavioral contexts and stimuli. PMID:27445151

Gamma and Beta Oscillations Define a Sequence of Neurocognitive Modes Present in Odor Processing.

PubMed

Frederick, Donald E; Brown, Austin; Brim, Elizabeth; Mehta, Nisarg; Vujovic, Mark; Kay, Leslie M

2016-07-20

Olfactory system beta (15-35 Hz) and gamma (40-110 Hz) oscillations of the local field potential in mammals have both been linked to odor learning and discrimination. Gamma oscillations represent the activity of a local network within the olfactory bulb, and beta oscillations represent engagement of a systemwide network. Here, we test whether beta and gamma oscillations represent different cognitive modes using the different demands of go/no-go and two-alternative choice tasks that previously were suggested to favor beta or gamma oscillations, respectively. We reconcile previous studies and show that both beta and gamma oscillations occur in both tasks, with gamma dominating the early odor sampling period (2-4 sniffs) and beta dominating later. The relative power and coherence of both oscillations depend separately on multiple factors within both tasks without categorical differences across tasks. While the early/gamma-associated period occurs in all trials, rats can perform above chance without the later/beta-associated period. Longer sampling, which includes beta oscillations, is associated with better performance. Gamma followed by beta oscillations therefore represents a sequence of cognitive and neural states during odor discrimination, which can be separately modified depending on the demands of a task and odor discrimination. Additionally, fast (85 Hz) and slow (70 Hz) olfactory bulb gamma oscillation sub-bands have been hypothesized to represent tufted and mitral cell networks, respectively (Manabe and Mori, 2013). We find that fast gamma favors the early and slow gamma the later (beta-dominated) odor-sampling period and that the relative contributions of these oscillations are consistent across tasks. Olfactory system gamma (40-110 Hz) and beta (15-35 Hz) oscillations of the local field potential indicate different neural firing statistics and functional circuits. We show that gamma and beta oscillations occur in stereotyped sequence during odor sampling in associative tasks, with local gamma dominating the first 250 ms of odor sniffing, followed by systemwide beta as behavioral responses are prepared. Oscillations and coupling strength between brain regions are modulated by task, odor, and learning, showing that task features can dramatically adjust the dynamics of a cortical sensory system, which changes state every ∼250 ms. Understanding cortical circuits, even at the biophysical level, depends on careful use of multiple behavioral contexts and stimuli. Copyright © 2016 the authors 0270-6474/16/367750-18$15.00/0.

Age-Related Differences in Reaction Time Task Performance in Young Children

ERIC Educational Resources Information Center

Kiselev, Sergey; Espy, Kimberlay Andrews; Sheffield, Tiffany

2009-01-01

Performance of reaction time (RT) tasks was investigated in young children and adults to test the hypothesis that age-related differences in processing speed supersede a "global" mechanism and are a function of specific differences in task demands and processing requirements. The sample consisted of 54 4-year-olds, 53 5-year-olds, 59…

Preliminary Findings on the Effects of Self-Referring and Evaluative Stimuli on Stimulus Equivalence Class Formation

ERIC Educational Resources Information Center

Merwin, Rhonda M.; Wilson, Kelly G.

2005-01-01

Thirty-two subjects completed 2 stimulus equivalence tasks using a matching-to-sample paradigm. One task involved direct reinforcement of conditional discriminations designed to produce derived relations between self-referring stimuli (e.g., me, myself, I) and positive evaluation words (e.g., whole, desirable, perfect). The other task was designed…

Using Multivariate Generalizability Theory to Assess the Effect of Content Stratification on the Reliability of a Performance Assessment

ERIC Educational Resources Information Center

Keller, Lisa A.; Clauser, Brian E.; Swanson, David B.

2010-01-01

In recent years, demand for performance assessments has continued to grow. However, performance assessments are notorious for lower reliability, and in particular, low reliability resulting from task specificity. Since reliability analyses typically treat the performance tasks as randomly sampled from an infinite universe of tasks, these estimates…

Using a Standardized Task to Assess the Quality of Teacher-Child Dyadic Interactions in Preschool

ERIC Educational Resources Information Center

Whittaker, Jessica E. V.; Williford, Amanda P.; Carter, Lauren M.; Vitiello, Virginia E.; Hatfield, Bridget E.

2018-01-01

Research Findings: This study explored the quality of teacher-child interactions within the context of a newly developed standardized task, Teacher-Child Structured Play Task (TC-SPT). A sample of 146 teachers and 345 children participated. Children who displayed the highest disruptive behaviors within each classroom were selected to participate.…

Influence of Ongoing Task Difficulty and Motivation Level on Children’s Prospective Memory in a Chinese Sample

PubMed Central

Han, Pi-guo; Han, Lei; Bian, Yu-long; Tian, Yu; Xu, Min-xia; Gao, Feng-qiang

2017-01-01

Prospective memory (PM) is the process associated with the task of realizing delayed intentions in the future. Researchers distinguish two types of PM, namely time-based PM (tbPM) and event-based PM (ebPM). Experiment 1 investigated the developmental trajectory of 3- to 5-year-old preschool children’s PM ability, and the occurrence of delayed retrieval (children execute the PM task in a larger window of opportunity) in both tbPM and ebPM tasks. Results revealed that the 5-year-old children outperformed the 3- and 4-year-old children in PM. Moreover, delayed retrieval was more likely to occur in tbPM task than in ebPM task. In Experiment 2, the influence of ongoing task (OT) difficulty on PM performance was investigated with a sample of 5-year-old children. Results revealed no significant effect of OT difficulty on PM performance. In Experiment 3, we improved children’s motivation level to complete the OT, then explored the influence of OT difficulty on children’s PM performance. Results revealed that the effect of OT difficulty on PM performance became significant after increasing the children’s motivation to complete the OT. These results provide insights into the mechanism of attentional resource allocation in PM tasks and have crucial educational and social implications. PMID:28203212

CAMS as a tool for human factors research in spaceflight

NASA Astrophysics Data System (ADS)

Sauer, Juergen

2004-01-01

The paper reviews a number of research studies that were carried out with a PC-based task environment called Cabin Air Management System (CAMS) simulating the operation of a spacecraft's life support system. As CAMS was a multiple task environment, it allowed the measurement of performance at different levels. Four task components of different priority were embedded in the task environment: diagnosis and repair of system faults, maintaining atmospheric parameters in a safe state, acknowledgement of system alarms (reaction time), and keeping a record of critical system resources (prospective memory). Furthermore, the task environment permitted the examination of different task management strategies and changes in crew member state (fatigue, anxiety, mental effort). A major goal of the research programme was to examine how crew members adapted to various forms of sub-optimal working conditions, such as isolation and confinement, sleep deprivation and noise. None of the studies provided evidence for decrements in primary task performance. However, the results showed a number of adaptive responses of crew members to adjust to the different sub-optimal working conditions. There was evidence for adjustments in information sampling strategies (usually reductions in sampling frequency) as a result of unfavourable working conditions. The results also showed selected decrements in secondary task performance. Prospective memory seemed to be somewhat more vulnerable to sub-optimal working conditions than performance on the reaction time task. Finally, suggestions are made for future research with the CAMS environment.

Monkey prefrontal neurons during Sternberg task performance: full contents of working memory or most recent item?

PubMed

Konecky, R O; Smith, M A; Olson, C R

2017-06-01

To explore the brain mechanisms underlying multi-item working memory, we monitored the activity of neurons in the dorsolateral prefrontal cortex while macaque monkeys performed spatial and chromatic versions of a Sternberg working-memory task. Each trial required holding three sequentially presented samples in working memory so as to identify a subsequent probe matching one of them. The monkeys were able to recall all three samples at levels well above chance, exhibiting modest load and recency effects. Prefrontal neurons signaled the identity of each sample during the delay period immediately following its presentation. However, as each new sample was presented, the representation of antecedent samples became weak and shifted to an anomalous code. A linear classifier operating on the basis of population activity during the final delay period was able to perform at approximately the level of the monkeys on trials requiring recall of the third sample but showed a falloff in performance on trials requiring recall of the first or second sample much steeper than observed in the monkeys. We conclude that delay-period activity in the prefrontal cortex robustly represented only the most recent item. The monkeys apparently based performance of this classic working-memory task on some storage mechanism in addition to the prefrontal delay-period firing rate. Possibilities include delay-period activity in areas outside the prefrontal cortex and changes within the prefrontal cortex not manifest at the level of the firing rate. NEW & NOTEWORTHY It has long been thought that items held in working memory are encoded by delay-period activity in the dorsolateral prefrontal cortex. Here we describe evidence contrary to that view. In monkeys performing a serial multi-item working memory task, dorsolateral prefrontal neurons encode almost exclusively the identity of the sample presented most recently. Information about earlier samples must be encoded outside the prefrontal cortex or represented within the prefrontal cortex in a cryptic code. Copyright © 2017 the American Physiological Society.

Sex differences on a computerized mental rotation task disappear with computer familiarization.

PubMed

Roberts, J E; Bell, M A

2000-12-01

The area of cognitive research that has produced the most consistent sex differences is spatial ability. Particularly, men consistently perform better on mental rotation tasks than do women. This study examined the effects of familiarization with a computer on performance of a computerized two-dimensional mental rotation task. Two groups of college students (N=44) performed the rotation task, with one group performing a color-matching task that allowed them to be familiarized with the computer prior to the rotation task. Among the participants who only performed the rotation task, the 11 men performed better than the 11 women. Among the participants who performed the computer familiarization task before the rotation task, how ever, there were no sex differences on the mental rotation task between the 10 men and 12 women. These data indicate that sex differences on this two-dimensional task may reflect familiarization with the computer, not the mental rotation component of the task. Further research with larger samples and increased range of task difficulty is encouraged.

Prefrontal electroencephalographic activity during the working memory processes involved in a sexually motivated task in male rats.

PubMed

Hernández-González, Marisela; Almanza-Sepúlveda, Mayra Linné; Olvera-Cortés, María Esther; Gutiérrez-Guzmán, Blanca Erika; Guevara, Miguel Angel

2012-08-01

The prefrontal cortex is involved in working memory functions, and several studies using food or drink as rewards have demonstrated that the rat is capable of performing tasks that involve working memory. Sexual activity is another highly-rewarding, motivated behaviour that has proven to be an efficient incentive in classical operant tasks. The objective of this study was to determine whether the functional activity of the medial prefrontal cortex (mPFC) changes in relation to the working memory processes involved in a sexually motivated task performed in male rats. Thus, male Wistar rats implanted in the mPFC were subjected to a nonmatching-to-sample task in a T-maze using sexual interaction as a reinforcer during a 4-day training period. On the basis of their performance during training, the rats were classified as 'good-learners' or 'bad-learners'. Only the good-learner rats showed an increase in the absolute power of the 8-13 Hz band during both the sample and test runs; a finding that could be related to learning of the working memory elements entailed in the task. During the maintenance phase only (i.e., once the rule had been learned well), the good-learner rats also showed an increased correlation of the 8-13 Hz band during the sample run, indicating that a high degree of coupling between the prefrontal cortices is necessary for the processing required to allow the rats to make correct decisions in the maintenance phase. Taken together, these data show that mPFC activity changes in relation to the working memory processes involved in a sexually motivated task in male rats.

Empirical study of seven data mining algorithms on different characteristics of datasets for biomedical classification applications.

PubMed

Zhang, Yiyan; Xin, Yi; Li, Qin; Ma, Jianshe; Li, Shuai; Lv, Xiaodan; Lv, Weiqi

2017-11-02

Various kinds of data mining algorithms are continuously raised with the development of related disciplines. The applicable scopes and their performances of these algorithms are different. Hence, finding a suitable algorithm for a dataset is becoming an important emphasis for biomedical researchers to solve practical problems promptly. In this paper, seven kinds of sophisticated active algorithms, namely, C4.5, support vector machine, AdaBoost, k-nearest neighbor, naïve Bayes, random forest, and logistic regression, were selected as the research objects. The seven algorithms were applied to the 12 top-click UCI public datasets with the task of classification, and their performances were compared through induction and analysis. The sample size, number of attributes, number of missing values, and the sample size of each class, correlation coefficients between variables, class entropy of task variable, and the ratio of the sample size of the largest class to the least class were calculated to character the 12 research datasets. The two ensemble algorithms reach high accuracy of classification on most datasets. Moreover, random forest performs better than AdaBoost on the unbalanced dataset of the multi-class task. Simple algorithms, such as the naïve Bayes and logistic regression model are suitable for a small dataset with high correlation between the task and other non-task attribute variables. K-nearest neighbor and C4.5 decision tree algorithms perform well on binary- and multi-class task datasets. Support vector machine is more adept on the balanced small dataset of the binary-class task. No algorithm can maintain the best performance in all datasets. The applicability of the seven data mining algorithms on the datasets with different characteristics was summarized to provide a reference for biomedical researchers or beginners in different fields.

A methodology to assess performance of human-robotic systems in achievement of collective tasks

NASA Technical Reports Server (NTRS)

Howard, Ayanna M.

2005-01-01

In this paper, we present a methodology to assess system performance of human-robotic systems in achievement of collective tasks such as habitat construction, geological sampling, and space exploration.

Making sense of the noise: Replication difficulties of Correll's (2008) modulation of 1/f noise in a racial bias task.

PubMed

Madurski, Christine; LeBel, Etienne P

2015-08-01

Correll (Journal of Personality and Social Psychology, 94, 48-59, 2008; Study 2) found that instructions to use or avoid race information decreased the emission of 1/f noise in a weapon identification task (WIT). These results suggested that 1/f noise in racial bias tasks reflected an effortful deliberative process, providing new insights regarding the mechanisms underlying implicit racial biases. Given the potential theoretical and applied importance of understanding the psychological processes underlying implicit racial biases - and in light of the growing demand for independent direct replications of findings to ensure the cumulative nature of our science - we attempted to replicate Correll's finding in two high-powered studies. Despite considerable effort to closely duplicate all procedural and methodological details of the original study (i.e., same cover story, experimental manipulation, implicit measure task, original stimuli, task instructions, sampling frame, population, and statistical analyses), both replication attempts were unsuccessful in replicating the original finding challenging the theoretical account that 1/f noise in racial bias tasks reflects a deliberative process. However, the emission of 1/f noise did consistently emerge across samples in each of our conditions. Hence, future research is needed to clarify the psychological significance of 1/f noise in racial bias tasks.

Task value profiles across subjects and aspirations to physical and IT-related sciences in the United States and Finland.

PubMed

Chow, Angela; Eccles, Jacquelynne S; Salmela-Aro, Katariina

2012-11-01

Two independent studies were conducted to extend previous research by examining the associations between task value priority patterns across school subjects and aspirations toward the physical and information technology- (IT-) related sciences. Study 1 measured task values of a sample of 10th graders in the United States (N = 249) across (a) physics and chemistry, (b) math, and (c) English. Study 2 measured task values of a sample of students in the second year of high school in Finland (N = 351) across (a) math and science, (b) Finnish, and (c) the arts and physical education. In both studies, students were classified into groups according to how they ranked math and science in relation to the other subjects. Regression analyses indicated that task value group membership significantly predicted subsequent aspirations toward physical and IT-related sciences measured 1-2 years later. The task value groups who placed the highest priority on math and science were significantly more likely to aspire to physical and IT-related sciences than were the other groups. These findings provide support for the theoretical assumption regarding the predictive role of intraindividual hierarchical patterns of task values for subsequent preferences and choices suggested by the Eccles [Parsons] (1983) expectancy-value model.

Instrumental methods of analysis of sulfur compounds in synfuel process streams. Quarterly technical progress report, July-September 1984

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

Jordan, J.; Talbott, J.

1984-01-01

Task 1. Methods development for the speciation of the polysulfides. Work on this task has been completed in December 1983 and reported accordingly in DOE/PC/40783-T13. Task 2. Methods development for the speciation of dithionite and polythionates. Work on Task 2 has been completed in June 1984 and has been reported accordingly in DOE/PC/40783-T15. Task 3. Total accounting of the sulfur balance in representative samples of synfuel process streams. A systematic and critical comparison of results, obtained in the analysis of sulfur moieties in representative samples of coal conversion process streams, revealed the following general trends. (a) In specimens of highmore » pH (9-10) and low redox potential (-0.3 to -0.4 volt versus NHE) sulfidic and polysulfidic sulfur moieties predominate. (b) In process streams of lower pH and more positive redox potential, higher oxidation states of sulfur (notably sulfate) account for most of the total sulfur present. (c) Oxidative wastewater treatment procedures by the PETC stripping process convert lower oxidation states of sulfur into thiosulfate and sulfate. In this context, remarkable similarities were observed between liquefaction and gasification process streams. However, the thiocyanate present in samples from the Grand Forks gasifier were impervious to the PETC stripping process. (d) Total sulfur contaminant levels in coal conversion process stream wastewater samples are primarily determined by the abundance of sulfur in the coal used as starting material than by the nature of the conversion process (liquefaction or gasification). 13 references.« less

Do children with grapheme-colour synaesthesia show cognitive benefits?

PubMed

Simner, Julia; Bain, Angela E

2018-02-01

Grapheme-colour synaesthesia is characterized by conscious and consistent associations between letters and colours, or between numbers and colours (e.g., synaesthetes might see A as red, 7 as green). Our study explored the development of this condition in a group of randomly sampled child synaesthetes. Two previous studies (Simner & Bain, 2013, Frontiers in Human Neuroscience, 7, 603; Simner, Harrold, Creed, Monro, & Foulkes, 2009, Brain, 132, 57) had screened over 600 primary school children to find the first randomly sampled cohort of child synaesthetes. In this study, we evaluate this cohort to ask whether their synaesthesia is associated with a particular cognitive profile of strengths and/or weaknesses. We tested our child synaesthetes at age 10-11 years in a series of cognitive tests, in comparison with matched controls and baseline norms. One previous study (Green & Goswami, 2008, Cognition, 106, 463) had suggested that child synaesthetes might perform differently to non-synaesthetes in such tasks, although those participants may have been a special type of population independent of their synaesthesia. In our own study of randomly sampled child synaesthetes, we found no significant advantages or disadvantages in a receptive vocabulary test and a memory matrix task. However, we found that synaesthetes demonstrated above-average performance in a processing-speed task and a near-significant advantage in a letter-span task (i.e., memory/recall task of letters). Our findings point to advantages for synaesthetes that go beyond those expected from enhanced coding accounts and we present the first picture of the broader cognitive profile of a randomly sampled population of child synaesthetes. © 2017 The British Psychological Society.

Anti-Icing Chitin Coating System Development

DTIC Science & Technology

1990-06-30

chitosan additives plus eight control samples were selected for the initial fungi testing. AsDeraillus oryzae (ATCC No. 10196) and Aspergillus niger...Task II work will determine the chitin/chitosan- paint suspensions standard ASTM test characteristics . Tasks III, IV and V will then center on the...five minutes to determine if full exposure of the chitin would increase the icephobic characteristics . Samples P2- BT-100 & 200-D and S7-BT-100 & 200-D

Decoding memory features from hippocampal spiking activities using sparse classification models.

PubMed

Dong Song; Hampson, Robert E; Robinson, Brian S; Marmarelis, Vasilis Z; Deadwyler, Sam A; Berger, Theodore W

2016-08-01

To understand how memory information is encoded in the hippocampus, we build classification models to decode memory features from hippocampal CA3 and CA1 spatio-temporal patterns of spikes recorded from epilepsy patients performing a memory-dependent delayed match-to-sample task. The classification model consists of a set of B-spline basis functions for extracting memory features from the spike patterns, and a sparse logistic regression classifier for generating binary categorical output of memory features. Results show that classification models can extract significant amount of memory information with respects to types of memory tasks and categories of sample images used in the task, despite the high level of variability in prediction accuracy due to the small sample size. These results support the hypothesis that memories are encoded in the hippocampal activities and have important implication to the development of hippocampal memory prostheses.

Supertaskers: Profiles in extraordinary multitasking ability.

PubMed

Watson, Jason M; Strayer, David L

2010-08-01

Theory suggests that driving should be impaired for any motorist who is concurrently talking on a cell phone. But is everybody impaired by this dual-task combination? We tested 200 participants in a high-fidelity driving simulator in both single- and dual-task conditions. The dual task involved driving while performing a demanding auditory version of the operation span (OSPAN) task. Whereas the vast majority of participants showed significant performance decrements in dual-task conditions (compared with single-task conditions for either driving or OSPAN tasks), 2.5% of the sample showed absolutely no performance decrements with respect to performing single and dual tasks. In single-task conditions, these "supertaskers" scored in the top quartile on all dependent measures associated with driving and OSPAN tasks, and Monte Carlo simulations indicated that the frequency of supertaskers was significantly greater than chance. These individual differences help to sharpen our theoretical understanding of attention and cognitive control in naturalistic settings.

Monitoring task loading with multivariate EEG measures during complex forms of human-computer interaction

NASA Technical Reports Server (NTRS)

Smith, M. E.; Gevins, A.; Brown, H.; Karnik, A.; Du, R.

2001-01-01

Electroencephalographic (EEG) recordings were made while 16 participants performed versions of a personal-computer-based flight simulation task of low, moderate, or high difficulty. As task difficulty increased, frontal midline theta EEG activity increased and alpha band activity decreased. A participant-specific function that combined multiple EEG features to create a single load index was derived from a sample of each participant's data and then applied to new test data from that participant. Index values were computed for every 4 s of task data. Across participants, mean task load index values increased systematically with increasing task difficulty and differed significantly between the different task versions. Actual or potential applications of this research include the use of multivariate EEG-based methods to monitor task loading during naturalistic computer-based work.

Perceptions of self-concept and self-presentation by procrastinators: further evidence.

PubMed

Ferrari, Joseph R; Díaz-Morales, Juan Francisco

2007-05-01

Two samples of university students completed self-report measures of chronic procrastination and either self-concept variables (Sample 1, n = 233) or self-presentational styles (Sample 2, n = 210). Results indicated that procrastination was significantly related to a self-concept of oneself as dominated by issues related to task performance, and to self-presentation strategies that reflected a person as continually justifying and excusing task delays and being "needy" of others' approval. It seems that men and women procrastinate in order to improve their social standing by making their accomplishments seem greater than they really are.

Development of Hot and Cool Executive Function during the Transition to Adolescence

ERIC Educational Resources Information Center

Prencipe, Angela; Kesek, Amanda; Cohen, Julia; Lamm, Connie; Lewis, Marc D.; Zelazo, Philip David

2011-01-01

This study examined the development of executive function (EF) in a typically developing sample from middle childhood to adolescence using a range of tasks varying in affective significance. A total of 102 participants between 8 and 15 years of age completed the Iowa Gambling Task, the Color Word Stroop, a Delay Discounting task, and a Digit Span…

The Impact of Reading Self-Efficacy and Task Value on Reading Comprehension Scores in Different Item Formats

ERIC Educational Resources Information Center

Solheim, Oddny Judith

2011-01-01

It has been hypothesized that students with low self-efficacy will struggle with complex reading tasks in assessment situations. In this study we examined whether perceived reading self-efficacy and reading task value uniquely predicted reading comprehension scores in two different item formats in a sample of fifth-grade students. Results showed…

A Teacher-Report Measure of Children's Task-Avoidant Behavior: A Validation Study of the Behavioral Strategy Rating Scale

ERIC Educational Resources Information Center

Zhang, Xiao; Nurmi, Jari-Erik; Kiuru, Noona; Lerkkanen, Marja-Kristiina; Aunola, Kaisa

2011-01-01

This study aims to validate a teacher-report measure of children's task-avoidant behavior, namely the Behavioral Strategy Rating Scale (BSRS), in a sample of 352 Finnish children. In each of the four waves from Kindergarten to Grade 2, teachers rated children's task-avoidant behavior using the BSRS, children completed reading and mathematics…

The Systems Approach to Functional Job Analysis. Task Analysis of the Physician's Assistant: Volume I--Task Analysis Methodology and Techniques.

ERIC Educational Resources Information Center

Wake Forest Univ., Winston Salem, NC. Bowman Gray School of Medicine.

Utilizing a systematic sampling technique, the professional activities of small groups of pediatricians, family practitioners, surgeons, obstetricians, and internists were observed for 4 or 5 days by a medical student who checked a prearranged activity sheet every 30 seconds to: (1) identify those tasks and activities an assistant could be trained…

Genetic pleiotropy explains associations between musical auditory discrimination and intelligence.

PubMed

Mosing, Miriam A; Pedersen, Nancy L; Madison, Guy; Ullén, Fredrik

2014-01-01

Musical aptitude is commonly measured using tasks that involve discrimination of different types of musical auditory stimuli. Performance on such different discrimination tasks correlates positively with each other and with intelligence. However, no study to date has explored these associations using a genetically informative sample to estimate underlying genetic and environmental influences. In the present study, a large sample of Swedish twins (N = 10,500) was used to investigate the genetic architecture of the associations between intelligence and performance on three musical auditory discrimination tasks (rhythm, melody and pitch). Phenotypic correlations between the tasks ranged between 0.23 and 0.42 (Pearson r values). Genetic modelling showed that the covariation between the variables could be explained by shared genetic influences. Neither shared, nor non-shared environment had a significant effect on the associations. Good fit was obtained with a two-factor model where one underlying shared genetic factor explained all the covariation between the musical discrimination tasks and IQ, and a second genetic factor explained variance exclusively shared among the discrimination tasks. The results suggest that positive correlations among musical aptitudes result from both genes with broad effects on cognition, and genes with potentially more specific influences on auditory functions.

Genetic Pleiotropy Explains Associations between Musical Auditory Discrimination and Intelligence

PubMed Central

Mosing, Miriam A.; Pedersen, Nancy L.; Madison, Guy; Ullén, Fredrik

2014-01-01

Musical aptitude is commonly measured using tasks that involve discrimination of different types of musical auditory stimuli. Performance on such different discrimination tasks correlates positively with each other and with intelligence. However, no study to date has explored these associations using a genetically informative sample to estimate underlying genetic and environmental influences. In the present study, a large sample of Swedish twins (N = 10,500) was used to investigate the genetic architecture of the associations between intelligence and performance on three musical auditory discrimination tasks (rhythm, melody and pitch). Phenotypic correlations between the tasks ranged between 0.23 and 0.42 (Pearson r values). Genetic modelling showed that the covariation between the variables could be explained by shared genetic influences. Neither shared, nor non-shared environment had a significant effect on the associations. Good fit was obtained with a two-factor model where one underlying shared genetic factor explained all the covariation between the musical discrimination tasks and IQ, and a second genetic factor explained variance exclusively shared among the discrimination tasks. The results suggest that positive correlations among musical aptitudes result from both genes with broad effects on cognition, and genes with potentially more specific influences on auditory functions. PMID:25419664

Working Memory, Language Skills, and Autism Symptomatology

PubMed Central

Schuh, Jillian M.; Eigsti, Inge-Marie

2012-01-01

While many studies have reported working memory (WM) impairments in autism spectrum disorders, others do not. Sample characteristics, WM domain, and task complexity likely contribute to these discrepancies. Although deficits in visuospatial WM have been more consistently documented, there is much controversy regarding verbal WM in autism. The goal of the current study was to explore visuospatial and verbal WM in a well-controlled sample of children with high-functioning autism (HFA) and typical development. Individuals ages 9–17 with HFA (n = 18) and typical development (n = 18), were carefully matched on gender, age, IQ, and language, and were administered a series of standardized visuospatial and verbal WM tasks. The HFA group displayed significant impairment across WM domains. No differences in performance were noted across WM tasks for either the HFA or typically developing groups. Over and above nonverbal cognition, WM abilities accounted for significant variance in language skills and symptom severity. The current study suggests broad WM limitations in HFA. We further suggest that deficits in verbal WM are observed in more complex tasks, as well as in simpler tasks, such as phonological WM. Increased task complexity and linguistic demands may influence WM abilities. PMID:25379222

ISOLOK VALVE ACCEPTANCE TESTING FOR DWPF SME SAMPLING PROCESS

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

Edwards, T.; Hera, K.; Coleman, C.

2011-12-05

Evaluation of the Defense Waste Processing Facility (DWPF) Chemical Process Cell (CPC) cycle time identified several opportunities to improve the CPC processing time. Of the opportunities, a focus area related to optimizing the equipment and efficiency of the sample turnaround time for DWPF Analytical Laboratory was identified. The Mechanical Systems & Custom Equipment Development (MS&CED) Section of the Savannah River National Laboratory (SRNL) evaluated the possibility of using an Isolok{reg_sign} sampling valve as an alternative to the Hydragard{reg_sign} valve for taking process samples. Previous viability testing was conducted with favorable results using the Isolok sampler and reported in SRNL-STI-2010-00749 (1).more » This task has the potential to improve operability, reduce maintenance time and decrease CPC cycle time. This report summarizes the results from acceptance testing which was requested in Task Technical Request (TTR) HLW-DWPF-TTR-2010-0036 (2) and which was conducted as outlined in Task Technical and Quality Assurance Plan (TTQAP) SRNL-RP-2011-00145 (3). The Isolok to be tested is the same model which was tested, qualified, and installed in the Sludge Receipt Adjustment Tank (SRAT) sample system. RW-0333P QA requirements apply to this task. This task was to qualify the Isolok sampler for use in the DWPF Slurry Mix Evaporator (SME) sampling process. The Hydragard, which is the current baseline sampling method, was used for comparison to the Isolok sampling data. The Isolok sampler is an air powered grab sampler used to 'pull' a sample volume from a process line. The operation of the sampler is shown in Figure 1. The image on the left shows the Isolok's spool extended into the process line and the image on the right shows the sampler retracted and then dispensing the liquid into the sampling container. To determine tank homogeneity, a Coliwasa sampler was used to grab samples at a high and low location within the mixing tank. Data from the two locations were compared to determine if the contents of the tank were well mixed. The Coliwasa sampler is a tube with a stopper at the bottom and is designed to obtain grab samples from specific locations within the drum contents. A position paper (4) was issued to address the prototypic flow loop issues and simulant selections. A statistically designed plan (5) was issued to address the total number of samples each sampler needed to pull, to provide the random order in which samples were pulled and to group samples for elemental analysis. The TTR required that the Isolok sampler perform as well as the Hydragard sampler during these tests to ensure the acceptability of the Isolok sampler for use in the DWPF sampling cells. Procedure No.L9.4-5015 was used to document the sample parameters and process steps. Completed procedures are located in R&D Engineering job folder 23269.« less

Order of stimulus presentation influences children's acquisition in receptive identification tasks.

PubMed

Petursdottir, Anna Ingeborg; Aguilar, Gabriella

2016-03-01

Receptive identification is usually taught in matching-to-sample format, which entails the presentation of an auditory sample stimulus and several visual comparison stimuli in each trial. Conflicting recommendations exist regarding the order of stimulus presentation in matching-to-sample trials. The purpose of this study was to compare acquisition in receptive identification tasks under 2 conditions: when the sample was presented before the comparisons (sample first) and when the comparisons were presented before the sample (comparison first). Participants included 4 typically developing kindergarten-age boys. Stimuli, which included birds and flags, were presented on a computer screen. Acquisition in the 2 conditions was compared in an adapted alternating-treatments design combined with a multiple baseline design across stimulus sets. All participants took fewer trials to meet the mastery criterion in the sample-first condition than in the comparison-first condition. © 2015 Society for the Experimental Analysis of Behavior.

Validation of Statistical Sampling Algorithms in Visual Sample Plan (VSP): Summary Report

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

Nuffer, Lisa L; Sego, Landon H.; Wilson, John E.

2009-02-18

The U.S. Department of Homeland Security, Office of Technology Development (OTD) contracted with a set of U.S. Department of Energy national laboratories, including the Pacific Northwest National Laboratory (PNNL), to write a Remediation Guidance for Major Airports After a Chemical Attack. The report identifies key activities and issues that should be considered by a typical major airport following an incident involving release of a toxic chemical agent. Four experimental tasks were identified that would require further research in order to supplement the Remediation Guidance. One of the tasks, Task 4, OTD Chemical Remediation Statistical Sampling Design Validation, dealt with statisticalmore » sampling algorithm validation. This report documents the results of the sampling design validation conducted for Task 4. In 2005, the Government Accountability Office (GAO) performed a review of the past U.S. responses to Anthrax terrorist cases. Part of the motivation for this PNNL report was a major GAO finding that there was a lack of validated sampling strategies in the U.S. response to Anthrax cases. The report (GAO 2005) recommended that probability-based methods be used for sampling design in order to address confidence in the results, particularly when all sample results showed no remaining contamination. The GAO also expressed a desire that the methods be validated, which is the main purpose of this PNNL report. The objective of this study was to validate probability-based statistical sampling designs and the algorithms pertinent to within-building sampling that allow the user to prescribe or evaluate confidence levels of conclusions based on data collected as guided by the statistical sampling designs. Specifically, the designs found in the Visual Sample Plan (VSP) software were evaluated. VSP was used to calculate the number of samples and the sample location for a variety of sampling plans applied to an actual release site. Most of the sampling designs validated are probability based, meaning samples are located randomly (or on a randomly placed grid) so no bias enters into the placement of samples, and the number of samples is calculated such that IF the amount and spatial extent of contamination exceeds levels of concern, at least one of the samples would be taken from a contaminated area, at least X% of the time. Hence, "validation" of the statistical sampling algorithms is defined herein to mean ensuring that the "X%" (confidence) is actually met.« less

The attention-weighted sample-size model of visual short-term memory: Attention capture predicts resource allocation and memory load.

PubMed

Smith, Philip L; Lilburn, Simon D; Corbett, Elaine A; Sewell, David K; Kyllingsbæk, Søren

2016-09-01

We investigated the capacity of visual short-term memory (VSTM) in a phase discrimination task that required judgments about the configural relations between pairs of black and white features. Sewell et al. (2014) previously showed that VSTM capacity in an orientation discrimination task was well described by a sample-size model, which views VSTM as a resource comprised of a finite number of noisy stimulus samples. The model predicts the invariance of [Formula: see text] , the sum of squared sensitivities across items, for displays of different sizes. For phase discrimination, the set-size effect significantly exceeded that predicted by the sample-size model for both simultaneously and sequentially presented stimuli. Instead, the set-size effect and the serial position curves with sequential presentation were predicted by an attention-weighted version of the sample-size model, which assumes that one of the items in the display captures attention and receives a disproportionate share of resources. The choice probabilities and response time distributions from the task were well described by a diffusion decision model in which the drift rates embodied the assumptions of the attention-weighted sample-size model. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

The disruptive effects of pain on n-back task performance in a large general population sample

PubMed Central

Attridge, Nina; Noonan, Donna; Eccleston, Christopher; Keogh, Edmund

2015-01-01

Abstract Pain captures attention, displaces current concerns, and prioritises escape and repair. This attentional capture can be measured by its effects on general cognition. Studies on induced pain, naturally occurring acute pain, and chronic pain all demonstrate a detrimental effect on specific tasks of attention, especially those that involve working memory. However, studies to date have relied on relatively small samples and/or one type of pain, thus restricting our ability to generalise to wider populations. We investigated the effect of pain on an n-back task in a large heterogeneous sample of 1318 adults. Participants were recruited from the general population and tested through the internet. Despite the heterogeneity of pain conditions, participant characteristics, and testing environments, we found a performance decrement on the n-back task for those with pain, compared with those without pain; there were significantly more false alarms on nontarget trials. Furthermore, we also found an effect of pain intensity; performance was poorer in participants with higher intensity compared with that in those with lower intensity pain. We suggest that the effects of pain on attention found in the laboratory occur in more naturalistic settings. Pain is common in the general population, and such interruption may have important, as yet uninvestigated, consequences for tasks of everyday cognition that involve working memory, such as concentration, reasoning, motor planning, and prospective memory. PMID:26020226

Inductive reasoning and the understanding of intention in schizophrenia.

PubMed

Corcoran, Rhiannon

2003-08-01

The study explored the relationship between the understanding of intention in veiled speech acts and the ability to reason inductively. A total of 39 people with DSM-IV-defined schizophrenia with no behavioural signs and 44 healthy participants performed the Hinting Task, a measure of pragmatic language in which the speaker's intention must be inferred, and a measure of inductive reasoning (Aha! Sentences) in which the meaning of ambiguous nonsocial sentences had to be inferred. The participants also completed measures of general intellectual ability, immediate memory for narrative and social problem-solving ability. A substantial correlation was found between performance on the inductive reasoning task and the Hinting Task in the sample of people with schizophrenia. The same relationship was not seen in the normal control sample. The robust relationship between these two measures in this sample survived when the roles of immediate memory for narrative and intellectual ability were controlled for. Furthermore, the relationship was distinctly more compelling for the patients who were currently ill compared to those in remission. These data suggest that people with schizophrenia use a different strategy to infer the meaning behind pragmatic language than that used by normally functioning adults. It is suggested that a reliance on different, possibly less specialised, skills in this group to perform this simple social inference task underlies their deficient performance on this and other measures of social inference. The fact that the relationship between the tasks in patients in remission is not as robust implies that the use of specialised skills to perform social inference tasks may be compromised most significantly during acute phases.

The significance of sense of coherence for the perceptions of task characteristics and stress during interruptions amongst a sample of public health nurses in Hong Kong: implications for nursing management.

PubMed

Shiu, A T

1998-08-01

The study aimed to investigate the significance of sense of coherence (SOC) for the perceptions of task characteristics and for stress perceptions during interruptions of public health nurses (PHNs) with children in Hong Kong. The research design employed the experience sampling method. Convenience sampling was used to recruit 20 subjects. During stage one of the study a watch was worn that gave a signal at six random times each day for seven days to complete an experience sampling diary. PHNs on average responded to 34 signals (80%) to complete the diaries which collected data on work and family juggling, task characteristics, and their effects on mood states. At stage two respondents completed the SOC scale which measured confidence in life as comprehensible, manageable, and meaningful. Two major findings provide the focus for this paper. First, results indicate that there was positive correlation between SOC and perceived task characteristics. Second, results reveal that when interruptions occurred, PHNs with high SOC had higher positive affect and lower negative affect than PHNs with low SOC. These results suggest that SOC as a salutogenic model helps PHNs to cope with the family and work juggling as well as the occupational stress. Implications for nursing management on strengthening SOC of PHNs are discussed.

Automated Proposition Density Analysis for Discourse in Aphasia.

PubMed

Fromm, Davida; Greenhouse, Joel; Hou, Kaiyue; Russell, G Austin; Cai, Xizhen; Forbes, Margaret; Holland, Audrey; MacWhinney, Brian

2016-10-01

This study evaluates how proposition density can differentiate between persons with aphasia (PWA) and individuals in a control group, as well as among subtypes of aphasia, on the basis of procedural discourse and personal narratives collected from large samples of participants. Participants were 195 PWA and 168 individuals in a control group from the AphasiaBank database. PWA represented 6 aphasia types on the basis of the Western Aphasia Battery-Revised (Kertesz, 2006). Narrative samples were stroke stories for PWA and illness or injury stories for individuals in the control group. Procedural samples were from the peanut-butter-and-jelly-sandwich task. Language samples were transcribed using Codes for the Human Analysis of Transcripts (MacWhinney, 2000) and analyzed using Computerized Language Analysis (MacWhinney, 2000), which automatically computes proposition density (PD) using rules developed for automatic PD measurement by the Computerized Propositional Idea Density Rater program (Brown, Snodgrass, & Covington, 2007; Covington, 2007). Participants in the control group scored significantly higher than PWA on both tasks. PD scores were significantly different among the aphasia types for both tasks. Pairwise comparisons for both discourse tasks revealed that PD scores for the Broca's group were significantly lower than those for all groups except Transcortical Motor. No significant quadratic or linear association between PD and severity was found. Proposition density is differentially sensitive to aphasia type and most clearly differentiates individuals with Broca's aphasia from the other groups.

Italian version of the task and ego orientation in sport questionnaire.

PubMed

Bortoli, Laura; Robazza, Claudio

2005-02-01

The 1992 Task and Ego Orientation in Sport Questionnaire developed by Duda and Nicholls was translated into Italian and administered to 802 young athletes, 248 girls and 554 boys aged 8 to 14 years, drawn from a range of individual and team sports, to examine its factor structure. Data sets of a calibration sample (boys 12-14 years) and of four cross-validation samples (boys 8-11 years, girls 8-11 years, boys 12-14 years, and girls 12-14 years) were subjected to confirmatory factor analysis specifying, as in the original questionnaire, an Ego Orientation scale (6 items) and a Task Orientation scale (7 items). Results across sex and age yielded chi2/df ratios ranging from 1.95 to 3.57, GFI indices above .90, AGFI indices ranging from .90 to .92, and RMSEA values not above .10. Findings provided acceptable support for the two-dimension structure of the test. In the whole sample, the Ego factor accounted for the 27.2% of variance and the Task factor accounted for the 33.5% of variance. Acceptable internal consistency of the two scales was also shown, with Cronbach alpha values ranging from .73 to .85.

Longitudinal effects of bilingualism on dual-tasking

PubMed Central

Josefsson, Maria; Marsh, John E.; Hansson, Patrik; Ljungberg, Jessica K.

2017-01-01

An ongoing debate surrounds whether bilinguals outperform monolinguals in tests of executive processing. The aim of this study was to investigate if there are long-term (10 year) bilingual advantages in executive processing, as indexed by dual-task performance, in a sample that were 40–65 years at baseline. The bilingual (n = 24) and monolingual (n = 24) participants were matched on age, sex, education, fluid intelligence, and study sample. Participants performed free-recall for a 12-item list in three dual-task settings wherein they sorted cards either during encoding, retrieval, or during both encoding and retrieval of the word-list. Free recall without card sorting was used as a reference to compute dual-task costs. The results showed that bilinguals significantly outperformed monolinguals when they performed card-sorting during both encoding and retrieval of the word-list, the condition that presumably placed the highest demands on executive functioning. However, dual-task costs increased over time for bilinguals relative to monolinguals, a finding that is possibly influenced by retirement age and limited use of second language in the bilingual group. PMID:29281654

Planetary image conversion task

NASA Technical Reports Server (NTRS)

Martin, M. D.; Stanley, C. L.; Laughlin, G.

1985-01-01

The Planetary Image Conversion Task group processed 12,500 magnetic tapes containing raw imaging data from JPL planetary missions and produced an image data base in consistent format on 1200 fully packed 6250-bpi tapes. The output tapes will remain at JPL. A copy of the entire tape set was delivered to US Geological Survey, Flagstaff, Ariz. A secondary task converted computer datalogs, which had been stored in project specific MARK IV File Management System data types and structures, to flat-file, text format that is processable on any modern computer system. The conversion processing took place at JPL's Image Processing Laboratory on an IBM 370-158 with existing software modified slightly to meet the needs of the conversion task. More than 99% of the original digital image data was successfully recovered by the conversion task. However, processing data tapes recorded before 1975 was destructive. This discovery is of critical importance to facilities responsible for maintaining digital archives since normal periodic random sampling techniques would be unlikely to detect this phenomenon, and entire data sets could be wiped out in the act of generating seemingly positive sampling results. Reccomended follow-on activities are also included.

Aspects of Students' Reasoning about Variation in Empirical Sampling Distributions

ERIC Educational Resources Information Center

Noll, Jennifer; Shaughnessy, J. Michael

2012-01-01

Sampling tasks and sampling distributions provide a fertile realm for investigating students' conceptions of variability. A project-designed teaching episode on samples and sampling distributions was team-taught in 6 research classrooms (2 middle school and 4 high school) by the investigators and regular classroom mathematics teachers. Data…

Behavioral reactivity to emotion challenge is associated with cortisol reactivity and regulation at 7, 15, and 24 months of age.

PubMed

Ursache, Alexandra; Blair, Clancy; Granger, Douglas A; Stifter, Cynthia; Voegtline, Kristin

2014-04-01

Emotionally arousing stimuli have been largely unsuccessful in eliciting cortisol responses in young children. Whether or not emotion challenge will elicit a cortisol response, however, may in part be determined by the extent to which the tasks elicit behavioral reactivity and regulation. We examined relations of behavioral reactivity and regulation to emotional arousal in the context of fear and frustration to the cortisol response at 7, 15, and 24 months of age in a low income, rural population based sample of 1,292 families followed longitudinally from birth. At each age, children participated in fear and frustration inducing tasks, and cortisol samples were taken at three time points (before the tasks began, 20 min following peak emotional arousal or after the series of tasks ended, and 40 min after peak arousal or the tasks ended) in order to capture both increases (reactivity) and subsequent decreases (regulation) in the cortisol response. Using multilevel models, we predicted the cortisol response from measures of behavioral reactivity and regulation. At 7 months of age, cortisol reactivity and recovery were related to behavioral reactivity during a frustration-eliciting task and marginally related to behavioral reactivity during a fear-eliciting task. At 15 and 24 months of age, however, cortisol reactivity and recovery were related only to behavioral reactivity during a fear-eliciting task. Results indicate that while behavioral reactivity is predictive of whether or not infants and young children will exhibit a cortisol response to emotionally arousing tasks, behavioral and cortisol reactivity are not necessarily coupled. © 2013 Wiley Periodicals, Inc.

Task Value Profiles across Subjects and Aspirations to Physical and IT-Related Sciences in the United States and Finland

ERIC Educational Resources Information Center

Chow, Angela; Eccles, Jacquelynne S.; Salmela-Aro, Katariina

2012-01-01

Two independent studies were conducted to extend previous research by examining the associations between task value priority patterns across school subjects and aspirations toward the physical and information technology- (IT-) related sciences. Study 1 measured task values of a sample of 10th graders in the United States (N = 249) across (a)…

Variable Lifting Index (VLI): A New Method for Evaluating Variable Lifting Tasks.

PubMed

Waters, Thomas; Occhipinti, Enrico; Colombini, Daniela; Alvarez-Casado, Enrique; Fox, Robert

2016-08-01

We seek to develop a new approach for analyzing the physical demands of highly variable lifting tasks through an adaptation of the Revised NIOSH (National Institute for Occupational Safety and Health) Lifting Equation (RNLE) into a Variable Lifting Index (VLI). There are many jobs that contain individual lifts that vary from lift to lift due to the task requirements. The NIOSH Lifting Equation is not suitable in its present form to analyze variable lifting tasks. In extending the prior work on the VLI, two procedures are presented to allow users to analyze variable lifting tasks. One approach involves the sampling of lifting tasks performed by a worker over a shift and the calculation of the Frequency Independent Lift Index (FILI) for each sampled lift and the aggregation of the FILI values into six categories. The Composite Lift Index (CLI) equation is used with lifting index (LI) category frequency data to calculate the VLI. The second approach employs a detailed systematic collection of lifting task data from production and/or organizational sources. The data are organized into simplified task parameter categories and further aggregated into six FILI categories, which also use the CLI equation to calculate the VLI. The two procedures will allow practitioners to systematically employ the VLI method to a variety of work situations where highly variable lifting tasks are performed. The scientific basis for the VLI procedure is similar to that for the CLI originally presented by NIOSH; however, the VLI method remains to be validated. The VLI method allows an analyst to assess highly variable manual lifting jobs in which the task characteristics vary from lift to lift during a shift. © 2015, Human Factors and Ergonomics Society.

Asymptotically Optimal Motion Planning for Learned Tasks Using Time-Dependent Cost Maps

PubMed Central

Bowen, Chris; Ye, Gu; Alterovitz, Ron

2015-01-01

In unstructured environments in people’s homes and workspaces, robots executing a task may need to avoid obstacles while satisfying task motion constraints, e.g., keeping a plate of food level to avoid spills or properly orienting a finger to push a button. We introduce a sampling-based method for computing motion plans that are collision-free and minimize a cost metric that encodes task motion constraints. Our time-dependent cost metric, learned from a set of demonstrations, encodes features of a task’s motion that are consistent across the demonstrations and, hence, are likely required to successfully execute the task. Our sampling-based motion planner uses the learned cost metric to compute plans that simultaneously avoid obstacles and satisfy task constraints. The motion planner is asymptotically optimal and minimizes the Mahalanobis distance between the planned trajectory and the distribution of demonstrations in a feature space parameterized by the locations of task-relevant objects. The motion planner also leverages the distribution of the demonstrations to significantly reduce plan computation time. We demonstrate the method’s effectiveness and speed using a small humanoid robot performing tasks requiring both obstacle avoidance and satisfaction of learned task constraints. Note to Practitioners Motivated by the desire to enable robots to autonomously operate in cluttered home and workplace environments, this paper presents an approach for intuitively training a robot in a manner that enables it to repeat the task in novel scenarios and in the presence of unforeseen obstacles in the environment. Based on user-provided demonstrations of the task, our method learns features of the task that are consistent across the demonstrations and that we expect should be repeated by the robot when performing the task. We next present an efficient algorithm for planning robot motions to perform the task based on the learned features while avoiding obstacles. We demonstrate the effectiveness of our motion planner for scenarios requiring transferring a powder and pushing a button in environments with obstacles, and we plan to extend our results to more complex tasks in the future. PMID:26279642

A Correlational Study of Seven Projective Spatial Structures with Regard to the Phases of the MOON^

NASA Astrophysics Data System (ADS)

Wellner, Karen Linette

1995-01-01

This study investigated the relationship between projective spatial structures and the ability to construct a scientific model. In addition, gender-related performance and the influence of prior astronomy experience on task success were evaluated. Sixty-one college science undergraduates were individually administered Piagetian tasks to assess for projective spatial structures and the ability to set up a phases of the moon model. The spatial tasks included: (a) Mountains task (coordination of perspectives); (b) Railroad task (size and intervals of objects with increasing distance); (c) Telephone Poles task (masking and ordering objects); and (d) Shadows task (spatial relationships between an object and its shadow, dependent upon the object's orientation). Cramer coefficient analyses indicated that significant relationships existed between Moon task and spatial task success. In particular, the Shadows task, requiring subjects to draw shadows of objects in different orientations, proved most difficult and was most strongly associated with with a subject's understanding of lunar phases. Chi-square tests for two independent samples were used to analyze gender performance differences on each of the Ave tasks. Males performed significantly better at a.05 significance level in regard to the Shadows task and the Moon task. Chi-square tests for two independent samples showed no significant difference in Moon task performance between subjects with astronomy or Earth science coursework, and those without such science classroom experience. Overall, only six subjects passed all seven projective spatial structure tasks. Piaget (1967) contends that concrete -operational spatial structures must be established before an individual is able to develop formal-operational patterns of thinking. The results of this study indicate that 90% of the interviewed science majors are still operating at the concrete-operational level. Several educational implications were drawn from this study: (1) The teaching of spatially dependent content to students without prerequisite spatial structures results in understanding no further beyond that which can be memorized; (2) assessment for projective spatial structures should precede science lessons dealing with time-space relationships, and (3) a student's level of spatial ability may directly impact upon interpretation of three-dimensional models.

Self-Relevant Disgust and Self-Harm Urges in Patients with Borderline Personality Disorder and Depression: A Pilot Study with a Newly Designed Psychological Challenge

PubMed Central

Abdul-Hamid, Sawsan; Denman, Chess; Dudas, Robert B.

2014-01-01

Background Borderline personality disorder (BPD) is a common psychiatric condition associated with self-harm. Self-harm is poorly understood and there is currently no treatment for acute presentations with self-harm urges. Objectives By using a new task (Self-relevant Task; SRT), to explore emotions related to one's own person (PERSON task) and body (BODY task), to study the correlations of these emotions, specifically disgust, with self-harm urge level changes, and to test the task's potential to be developed into an experimental model of self-harming for treatment trials. Methods 17 BPD patients, 27 major depressive disorder (MDD) patients, and 25 healthy volunteers performed the SRT. Emotion labels were extracted from task narratives and disgust and self-harm urge level changes measured by visual analogue scales. We used validated rating scales to measure symptom severity. Results The SRT was effective at inducing negative emotions and self-harm urge changes. Self-harm urge changes correlated with borderline symptom severity. Post-task disgust levels on the visual analogue scales were higher in BPD patients than in healthy controls in the PERSON task, and higher than in both control groups in the BODY task. Changes in disgust levels during the task were significantly greater in the patient groups. Post-task disgust levels or changes in disgust were not associated with self-harm urge changes (except the latter in MDD in the PERSON task), but self-harm urge changes and disgust (but no other emotion) narrative labels were on a whole sample level. Conclusion Although associations with the analogue scale measures were not significant, self-disgust reported in the narrative of patients may be associated with a higher probability of self-harm urges. Further research with larger sample sizes is needed to confirm this relationship and to examine whether reducing self-disgust could reduce self-harm urges. The SRT was effective and safe, and could be standardized for experimental studies. PMID:24956153

Results of Hg speciation testing on DWPF SMECT-8, OGCT-1, AND OGCT-2 samples

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

Bannochie, C.

2016-02-22

The Savannah River National Laboratory (SRNL) was tasked with preparing and shipping samples for Hg speciation by Eurofins Frontier Global Sciences, Inc. in Seattle, WA on behalf of the Savannah River Remediation (SRR) Mercury Task Team. The sixteenth shipment of samples was designated to include a Defense Waste Processing Facility (DWPF) Slurry Mix Evaporator Condensate Tank (SMECT) sample from Sludge Receipt and Adjustment Tank (SRAT) Batch 738 processing and two Off-Gas Condensate Tank (OGCT) samples, one following Batch 736 and one following Batch 738. The DWPF sample designations for the three samples analyzed are provided. The Batch 738 ‘End ofmore » SME Cycle’ SMECT sample was taken at the conclusion of Slurry Mix Evaporator (SME) operations for this batch and represents the fourth SMECT sample examined from Batch 738. Batch 738 experienced a sludge slurry carryover event, which introduced sludge solids to the SMECT that were particularly evident in the SMECT-5 sample, but less evident in the ‘End of SME Cycle’ SMECT-8 sample.« less

Using psychophysics to ask if the brain samples or maximizes

PubMed Central

Acuna, Daniel E.; Berniker, Max; Fernandes, Hugo L.; Kording, Konrad P.

2015-01-01

The two-alternative forced-choice (2AFC) task is the workhorse of psychophysics and is used to measure the just-noticeable difference, generally assumed to accurately quantify sensory precision. However, this assumption is not true for all mechanisms of decision making. Here we derive the behavioral predictions for two popular mechanisms, sampling and maximum a posteriori, and examine how they affect the outcome of the 2AFC task. These predictions are used in a combined visual 2AFC and estimation experiment. Our results strongly suggest that subjects use a maximum a posteriori mechanism. Further, our derivations and experimental paradigm establish the already standard 2AFC task as a behavioral tool for measuring how humans make decisions under uncertainty. PMID:25767093

Meta-analysis of age and skill effects on recalling chess positions and selecting the best move.

PubMed

Moxley, Jerad H; Charness, Neil

2013-10-01

A meta-analysis was conducted of studies that measured the effects of both age and skill in chess on the tasks of selecting the best move for chess positions (the best move task) as well as recalling chess game positions (the recall task). Despite a small sample of studies, we demonstrated that there are age and skill effects on both tasks: age being negatively associated with performance on both tasks and skill being positively associated with performance on both tasks. On the best move task, we found that skill was the dominant effect, while on the recall task, skill and age were approximately equally strong effects. We also found that skill was best measured by the best move task. In the case of the best move task, this result is consistent with the argument that it accurately replicates expert performance (Ericsson & Smith, 1991). Results for the recall task argue that this task captures effects related to skill, but also effects likely due to a general aging process. Implications for our understanding of aging in skilled domains are also discussed.

Exploring Dimensionality of Effortful Control Using Hot and Cool Tasks in a Sample of Preschool Children

PubMed Central

Allan, Nicholas P.; Lonigan, Christopher J.

2015-01-01

Effortful control (EC) is an important developmental construct associated with academic performance, socioemotional growth, and psychopathology. EC, defined as the ability to inhibit or delay a prepotent response typically in favor of a subdominant response, undergoes rapid development during children’s preschool years. Research involving EC in preschool children can be aided by ensuring that the measured model of EC matches the latent structure of EC. Extant research indicates that EC may be multidimensional, consisting of hot (affectively salient) and cool (affectively neutral) dimensions. However, there are several untested assumptions regarding the defining features of hot EC. Confirmatory factor analysis was used in a sample of 281 preschool children (Mage = 55.92 - months, SD = 4.16; 46.6% male and 53.4% female) to compare a multidimensional model composed of hot and cool EC factors with a unidimensional model. Hot tasks were created by adding affective salience to cool tasks so that hot and cool tasks varied only by this aspect of the tasks. Tasks measuring EC were best described by a single factor and not distinct hot and cool factors, indicating that affective salience alone does not differentiate between hot and cool EC. EC shared gender-invariant associations with academic skills and externalizing behavior problems. PMID:24518050

Exploring dimensionality of effortful control using hot and cool tasks in a sample of preschool children.

PubMed

Allan, Nicholas P; Lonigan, Christopher J

2014-06-01

Effortful control (EC) is an important developmental construct associated with academic performance, socioemotional growth, and psychopathology. EC, defined as the ability to inhibit or delay a prepotent response typically in favor of a subdominant response, undergoes rapid development during children's preschool years. Research involving EC in preschool children can be aided by ensuring that the measured model of EC matches the latent structure of EC. Extant research indicates that EC may be multidimensional, consisting of hot (affectively salient) and cool (affectively neutral) dimensions. However, there are several untested assumptions regarding the defining features of hot EC. Confirmatory factor analysis was used in a sample of 281 preschool children (Mage=55.92months, SD=4.16; 46.6% male and 53.4% female) to compare a multidimensional model composed of hot and cool EC factors with a unidimensional model. Hot tasks were created by adding affective salience to cool tasks so that hot and cool tasks varied only by this aspect of the tasks. Tasks measuring EC were best described by a single factor and not distinct hot and cool factors, indicating that affective salience alone does not differentiate between hot and cool EC. EC shared gender-invariant associations with academic skills and externalizing behavior problems. Copyright © 2013 Elsevier Inc. All rights reserved.

Job task-competency linkages for FAA first-level supervisors.

DOT National Transportation Integrated Search

1991-04-01

A study was conducted to determine the linkages between the job tasks and competencies of first level supervisors in the FAA. A sample was drawn from each of nine job groups: Flight Service, Terminal, En Route, Regional Office/Headquarters Air Traffi...

Test-retest reliability of an fMRI paradigm for studies of cardiovascular reactivity.

PubMed

Sheu, Lei K; Jennings, J Richard; Gianaros, Peter J

2012-07-01

We examined the reliability of measures of fMRI, subjective, and cardiovascular reactions to standardized versions of a Stroop color-word task and a multisource interference task. A sample of 14 men and 12 women (30-49 years old) completed the tasks on two occasions, separated by a median of 88 days. The reliability of fMRI BOLD signal changes in brain areas engaged by the tasks was moderate, and aggregating fMRI BOLD signal changes across the tasks improved test-retest reliability metrics. These metrics included voxel-wise intraclass correlation coefficients (ICCs) and overlap ratio statistics. Task-aggregated ratings of subjective arousal, valence, and control, as well as cardiovascular reactions evoked by the tasks showed ICCs of 0.57 to 0.87 (ps < .001), indicating moderate-to-strong reliability. These findings support using these tasks as a battery for fMRI studies of cardiovascular reactivity. Copyright © 2012 Society for Psychophysiological Research.

Task difficulty moderates the revelation effect.

PubMed

Aßfalg, André; Currie, Devon; Bernstein, Daniel M

2017-05-01

Tasks that precede a recognition probe induce a more liberal response criterion than do probes without tasks-the "revelation effect." For example, participants are more likely to claim that a stimulus is familiar directly after solving an anagram, relative to a condition without an anagram. Revelation effect hypotheses disagree whether hard preceding tasks should produce a larger revelation effect than easy preceding tasks. Although some studies have shown that hard tasks increase the revelation effect as compared to easy tasks, these studies suffered from a confound of task difficulty and task presence. Conversely, other studies have shown that the revelation effect is independent of task difficulty. In the present study, we used new task difficulty manipulations to test whether hard tasks produce larger revelation effects than easy tasks. Participants (N = 464) completed hard or easy preceding tasks, including anagrams (Exps. 1 and 2) and the typing of specific arrow key sequences (Exps. 3-6). With sample sizes typical of revelation effect experiments, the effect sizes of task difficulty on the revelation effect varied considerably across experiments. Despite this variability, a consistent data pattern emerged: Hard tasks produced larger revelation effects than easy tasks. Although the present study falsifies certain revelation effect hypotheses, the general vagueness of revelation effect hypotheses remains.

Age-related decrements in dual-task performance: Comparison of different mobility and cognitive tasks. A cross sectional study.

PubMed

Brustio, Paolo Riccardo; Magistro, Daniele; Zecca, Massimiliano; Rabaglietti, Emanuela; Liubicich, Monica Emma

2017-01-01

This cross-sectional study investigated the age-related differences in dual-task performance both in mobility and cognitive tasks and the additive dual-task costs in a sample of older, middle-aged and young adults. 74 older adults (M = 72.63±5.57 years), 58 middle-aged adults (M = 46.69±4.68 years) and 63 young adults (M = 25.34±3.00 years) participated in the study. Participants performed different mobility and subtraction tasks under both single- and dual-task conditions. Linear regressions, repeated-measures and one-way analyses of covariance were used, The results showed: significant effects of the age on the dual and mobility tasks (p<0.05) and differences among the age-groups in the combined dual-task costs (p<0.05); significant decreases in mobility performance under dual-task conditions in all groups (p<0.05) and a decrease in cognitive performance in the older group (p<0.05). Dual-task activity affected mobility and cognitive performance, especially in older adults who showed a higher dual-task cost, suggesting that dual-tasks activities are affected by the age and consequently also mobility and cognitive tasks are negatively influenced.

Emotion dysregulation and autonomic responses to film, rumination, and body awareness: Extending psychophysiological research to a naturalistic clinical setting and a chemically dependent female sample.

PubMed

Crowell, Sheila E; Price, Cynthia J; Puzia, Megan E; Yaptangco, Mona; Cheng, Sunny Chieh

2017-05-01

Substance use is a complex clinical problem characterized by emotion dysregulation and daily challenges that can interfere with laboratory research. Thus, few psychophysiological studies examine autonomic and self-report measures of emotion dysregulation with multidiagnostic, chemically dependent samples or extend this work into naturalistic settings. In this study, we used a within-subject design to examine changes in respiratory sinus arrhythmia (RSA), electrodermal activity (EDA), and self-reported affect across three tasks designed to elicit distinct psychophysiological and emotional response patterns. We also examined emotion dysregulation as a moderator of psychophysiological responses. Participants include 116 women with multiple comorbid mental health conditions enrolled in substance use treatment, many of whom also reported high emotion dysregulation. Participants were assessed in the treatment setting and completed three tasks: watching a sad movie clip, rumination on a stressful event, and a mindful interoceptive awareness meditation. Multilevel models were used to examine changes from resting baselines to the tasks. During the film, results indicate a significant decrease in RSA and an increase in EDA. For the rumination task, participants showed a decrease in RSA but no EDA response. For the body awareness task, there was an increase in RSA and a decrease in EDA. Emotion dysregulation was associated with differences in baseline RSA but not with EDA or with the slope of response patterns across tasks. Self-reported affect was largely consistent with autonomic patterns. Findings add to the literature on emotion dysregulation, substance use, and the translation of psychophysiological measurements into clinical settings with complex samples. © 2017 Society for Psychophysiological Research.

Right Fronto-Subcortical White Matter Microstructure Predicts Cognitive Control Ability on the Go/No-go Task in a Community Sample.

PubMed

Hinton, Kendra E; Lahey, Benjamin B; Villalta-Gil, Victoria; Boyd, Brian D; Yvernault, Benjamin C; Werts, Katherine B; Plassard, Andrew J; Applegate, Brooks; Woodward, Neil D; Landman, Bennett A; Zald, David H

2018-01-01

Go/no-go tasks are widely used to index cognitive control. This construct has been linked to white matter microstructure in a circuit connecting the right inferior frontal gyrus (IFG), subthalamic nucleus (STN), and pre-supplementary motor area. However, the specificity of this association has not been tested. A general factor of white matter has been identified that is related to processing speed. Given the strong processing speed component in successful performance on the go/no-go task, this general factor could contribute to task performance, but the general factor has often not been accounted for in past studies of cognitive control. Further, studies on cognitive control have generally employed small unrepresentative case-control designs. The present study examined the relationship between go/no-go performance and white matter microstructure in a large community sample of 378 subjects that included participants with a range of both clinical and subclinical nonpsychotic psychopathology. We found that white matter microstructure properties in the right IFG-STN tract significantly predicted task performance, and remained significant after controlling for dimensional psychopathology. The general factor of white matter only reached statistical significance when controlling for dimensional psychopathology. Although the IFG-STN and general factor tracts were highly correlated, when both were included in the model, only the IFG-STN remained a significant predictor of performance. Overall, these findings suggest that while a general factor of white matter can be identified in a young community sample, white matter microstructure properties in the right IFG-STN tract show a specific relationship to cognitive control. The findings highlight the importance of examining both specific and general correlates of cognition, especially in tasks with a speeded component.

A Systematic Review and Meta-Analysis of the Effects of Transcranial Direct Current Stimulation (tDCS) Over the Dorsolateral Prefrontal Cortex in Healthy and Neuropsychiatric Samples: Influence of Stimulation Parameters.

PubMed

Dedoncker, Josefien; Brunoni, Andre R; Baeken, Chris; Vanderhasselt, Marie-Anne

2016-01-01

Research into the effects of transcranial direct current stimulation of the dorsolateral prefrontal cortex on cognitive functioning is increasing rapidly. However, methodological heterogeneity in prefrontal tDCS research is also increasing, particularly in technical stimulation parameters that might influence tDCS effects. To systematically examine the influence of technical stimulation parameters on DLPFC-tDCS effects. We performed a systematic review and meta-analysis of tDCS studies targeting the DLPFC published from the first data available to February 2016. Only single-session, sham-controlled, within-subject studies reporting the effects of tDCS on cognition in healthy controls and neuropsychiatric patients were included. Evaluation of 61 studies showed that after single-session a-tDCS, but not c-tDCS, participants responded faster and more accurately on cognitive tasks. Sub-analyses specified that following a-tDCS, healthy subjects responded faster, while neuropsychiatric patients responded more accurately. Importantly, different stimulation parameters affected a-tDCS effects, but not c-tDCS effects, on accuracy in healthy samples vs. increased current density and density charge resulted in improved accuracy in healthy samples, most prominently in females; for neuropsychiatric patients, task performance during a-tDCS resulted in stronger increases in accuracy rates compared to task performance following a-tDCS. Healthy participants respond faster, but not more accurate on cognitive tasks after a-tDCS. However, increasing the current density and/or charge might be able to enhance response accuracy, particularly in females. In contrast, online task performance leads to greater increases in response accuracy than offline task performance in neuropsychiatric patients. Possible implications and practical recommendations are discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

Use of the internet to study the utility values of the public.

PubMed Central

Lenert, Leslie A.; Sturley, Ann E.

2002-01-01

One of the most difficult tasks in cost-effectiveness analysis is the measurement of quality weights (utilities) for health states. The task is difficult because subjects often lack familiarity with health states they are asked to rate and because utilities measures such as the standard gamble, ask subjects to perform tasks that are complex and far from everyday experience. A large body of research suggests that computer methods can play an important role in explaining health states and measuring utilities. However, administering computer surveys to a "general public" sample, the most relevant sample for cost-effectiveness analysis, is logistically difficult. In this paper, we describe a software system designed to allow the study of general population preferences in a volunteer Internet survey panel. The approach, which relied on over sampling of ethnic groups and older members of the panel, produced a data set with an ethnically, chronologically and geographically diverse group of respondents, but was not successful in replicating the joint distribution of demographic patterns in the population. PMID:12463862

Mars Technology Rover with Arm-Mounted Percussive Coring Tool, Microimager, and Sample-Handling Encapsulation Containerization Subsystem

NASA Technical Reports Server (NTRS)

Younse, Paulo J.; Dicicco, Matthew A.; Morgan, Albert R.

2012-01-01

A report describes the PLuto (programmable logic) Mars Technology Rover, a mid-sized FIDO (field integrated design and operations) class rover with six fully drivable and steerable cleated wheels, a rocker-bogey suspension, a pan-tilt mast with panorama and navigation stereo camera pairs, forward and rear stereo hazcam pairs, internal avionics with motor drivers and CPU, and a 5-degrees-of-freedom robotic arm. The technology rover was integrated with an arm-mounted percussive coring tool, microimager, and sample handling encapsulation containerization subsystem (SHEC). The turret of the arm contains a percussive coring drill and microimager. The SHEC sample caching system mounted to the rover body contains coring bits, sample tubes, and sample plugs. The coring activities performed in the field provide valuable data on drilling conditions for NASA tasks developing and studying coring technology. Caching of samples using the SHEC system provide insight to NASA tasks investigating techniques to store core samples in the future.

Variable Lifting Index (VLI)

PubMed Central

Waters, Thomas; Occhipinti, Enrico; Colombini, Daniela; Alvarez-Casado, Enrique; Fox, Robert

2015-01-01

Objective: We seek to develop a new approach for analyzing the physical demands of highly variable lifting tasks through an adaptation of the Revised NIOSH (National Institute for Occupational Safety and Health) Lifting Equation (RNLE) into a Variable Lifting Index (VLI). Background: There are many jobs that contain individual lifts that vary from lift to lift due to the task requirements. The NIOSH Lifting Equation is not suitable in its present form to analyze variable lifting tasks. Method: In extending the prior work on the VLI, two procedures are presented to allow users to analyze variable lifting tasks. One approach involves the sampling of lifting tasks performed by a worker over a shift and the calculation of the Frequency Independent Lift Index (FILI) for each sampled lift and the aggregation of the FILI values into six categories. The Composite Lift Index (CLI) equation is used with lifting index (LI) category frequency data to calculate the VLI. The second approach employs a detailed systematic collection of lifting task data from production and/or organizational sources. The data are organized into simplified task parameter categories and further aggregated into six FILI categories, which also use the CLI equation to calculate the VLI. Results: The two procedures will allow practitioners to systematically employ the VLI method to a variety of work situations where highly variable lifting tasks are performed. Conclusions: The scientific basis for the VLI procedure is similar to that for the CLI originally presented by NIOSH; however, the VLI method remains to be validated. Application: The VLI method allows an analyst to assess highly variable manual lifting jobs in which the task characteristics vary from lift to lift during a shift. PMID:26646300

Satellite Image Classification of Building Damages Using Airborne and Satellite Image Samples in a Deep Learning Approach

NASA Astrophysics Data System (ADS)

Duarte, D.; Nex, F.; Kerle, N.; Vosselman, G.

2018-05-01

The localization and detailed assessment of damaged buildings after a disastrous event is of utmost importance to guide response operations, recovery tasks or for insurance purposes. Several remote sensing platforms and sensors are currently used for the manual detection of building damages. However, there is an overall interest in the use of automated methods to perform this task, regardless of the used platform. Owing to its synoptic coverage and predictable availability, satellite imagery is currently used as input for the identification of building damages by the International Charter, as well as the Copernicus Emergency Management Service for the production of damage grading and reference maps. Recently proposed methods to perform image classification of building damages rely on convolutional neural networks (CNN). These are usually trained with only satellite image samples in a binary classification problem, however the number of samples derived from these images is often limited, affecting the quality of the classification results. The use of up/down-sampling image samples during the training of a CNN, has demonstrated to improve several image recognition tasks in remote sensing. However, it is currently unclear if this multi resolution information can also be captured from images with different spatial resolutions like satellite and airborne imagery (from both manned and unmanned platforms). In this paper, a CNN framework using residual connections and dilated convolutions is used considering both manned and unmanned aerial image samples to perform the satellite image classification of building damages. Three network configurations, trained with multi-resolution image samples are compared against two benchmark networks where only satellite image samples are used. Combining feature maps generated from airborne and satellite image samples, and refining these using only the satellite image samples, improved nearly 4 % the overall satellite image classification of building damages.

Qualitative Meta-Analysis on the Hospital Task: Implications for Research

ERIC Educational Resources Information Center

Noll, Jennifer; Sharma, Sashi

2014-01-01

The "law of large numbers" indicates that as sample size increases, sample statistics become less variable and more closely estimate their corresponding population parameters. Different research studies investigating how people consider sample size when evaluating the reliability of a sample statistic have found a wide range of…

A Population of Assessment Tasks

ERIC Educational Resources Information Center

Daro, Phil; Burkhardt, Hugh

2012-01-01

We propose the development of a "population" of high-quality assessment tasks that cover the performance goals set out in the "Common Core State Standards for Mathematics." The population will be published. Tests are drawn from this population as a structured random sample guided by a "balancing algorithm."

Mnemonic neuronal activity in somatosensory cortex.

PubMed Central

Zhou, Y D; Fuster, J M

1996-01-01

Single-unit activity was recorded from the hand areas of the somatosensory cortex of monkeys trained to perform a haptic delayed matching to sample task with objects of identical dimensions but different surface features. During the memory retention period of the task (delay), many units showed sustained firing frequency change, either excitation or inhibition. In some cases, firing during that period was significantly higher after one sample object than after another. These observations indicate the participation of somatosensory neurons not only in the perception but in the short-term memory of tactile stimuli. Neurons most directly implicated in tactile memory are (i) those with object-selective delay activity, (ii) those with nondifferential delay activity but without activity related to preparation for movement, and (iii) those with delay activity in the haptic-haptic delayed matching task but no such activity in a control visuo-haptic delayed matching task. The results indicate that cells in early stages of cortical somatosensory processing participate in haptic short-term memory. PMID:8927629

Factors involved in making post-performance judgments in mathematics problem-solving.

PubMed

García Fernández, Trinidad; Kroesbergen, Evelyn; Rodríguez Pérez, Celestino; González-Castro, Paloma; González-Pienda, Julio A

2015-01-01

This study examines the impact of executive functions, affective-motivational variables related to mathematics, mathematics achievement and task characteristics on fifth and sixth graders’ calibration accuracy after completing two mathematical problems. A sample of 188 students took part in the study. They were divided into two groups as function of their judgment accuracy after completing the two tasks (accurate= 79, inaccurate= 109). Differences between these groups were examined. The discriminative value of these variables to predict group membership was analyzed, as well as the effect of age, gender, and grade level. The results indicated that accurate students showed better levels of executive functioning, and more positive feelings, beliefs, and motivation related to mathematics. They also spent more time on the tasks. Mathematics achievement, perceived usefulness of mathematics, and time spent on Task 1 significantly predicted group membership, classifying 71.3% of the sample correctly. These results support the relationship between academic achievement and calibration accuracy, suggesting the need to consider a wide range of factors when explaining performance judgments.

Blunted cardiac reactivity to psychological stress associated with higher trait anxiety: a study in peacekeepers.

PubMed

Souza, Gabriela Guerra Leal; Mendonça-de-Souza, Ana Carolina Ferraz; Duarte, Antônio Fernando Araújo; Fischer, Nastassja Lopes; Souza, Wanderson Fernandes; Coutinho, Evandro Silva Freire; Figueira, Ivan; Volchan, Eliane

2015-11-23

Both exaggerated and diminished reactivity to stress can be maladaptive. Previous studies have shown that performing increasingly difficult tasks leads first to increased reactivity and then to a blunted response when success is impossible. Our aim was to investigate the influence of trait anxiety on cardiac and cortisol response to and recovery from a standardized psychosocial stress task (Trier Social Stress Task) in a homogeneous sample of healthy peacekeepers. We hypothesized that participants with higher trait anxiety would show blunted reactivity during the performance of an overwhelmingly difficult and stressful task. Participants (N = 50) delivered a speech and performed an arithmetic task in the presence of critical evaluators. Cortisol samples and electrocardiogram data were collected. Participants completed the State-Trait Anxiety Inventory-Trait version, the Posttraumatic Stress Disorder Checklist-Civilian Version (PCL-C) and the Military Peace Force Stressor Inventory. For heart rate, the findings showed that peacekeepers with higher trait anxiety reacted less to the speech task (p = 0.03) and to the arithmetic task (p = 0.008) than those with lower trait anxiety. Trait anxiety did not modulate cortisol responses to the task. Despite the high trait anxiety group having higher PCL-C scores than the low trait anxiety group (p < 0.0001), this did not influence the cardiac results. We concluded that individuals with higher trait anxiety had less tachycardia in response to acute psychological stress than those with lower trait anxiety. The present results point to a higher risk for more anxious individuals of a maladaptive reaction to stressful events.

A study of active learning methods for named entity recognition in clinical text.

PubMed

Chen, Yukun; Lasko, Thomas A; Mei, Qiaozhu; Denny, Joshua C; Xu, Hua

2015-12-01

Named entity recognition (NER), a sequential labeling task, is one of the fundamental tasks for building clinical natural language processing (NLP) systems. Machine learning (ML) based approaches can achieve good performance, but they often require large amounts of annotated samples, which are expensive to build due to the requirement of domain experts in annotation. Active learning (AL), a sample selection approach integrated with supervised ML, aims to minimize the annotation cost while maximizing the performance of ML-based models. In this study, our goal was to develop and evaluate both existing and new AL methods for a clinical NER task to identify concepts of medical problems, treatments, and lab tests from the clinical notes. Using the annotated NER corpus from the 2010 i2b2/VA NLP challenge that contained 349 clinical documents with 20,423 unique sentences, we simulated AL experiments using a number of existing and novel algorithms in three different categories including uncertainty-based, diversity-based, and baseline sampling strategies. They were compared with the passive learning that uses random sampling. Learning curves that plot performance of the NER model against the estimated annotation cost (based on number of sentences or words in the training set) were generated to evaluate different active learning and the passive learning methods and the area under the learning curve (ALC) score was computed. Based on the learning curves of F-measure vs. number of sentences, uncertainty sampling algorithms outperformed all other methods in ALC. Most diversity-based methods also performed better than random sampling in ALC. To achieve an F-measure of 0.80, the best method based on uncertainty sampling could save 66% annotations in sentences, as compared to random sampling. For the learning curves of F-measure vs. number of words, uncertainty sampling methods again outperformed all other methods in ALC. To achieve 0.80 in F-measure, in comparison to random sampling, the best uncertainty based method saved 42% annotations in words. But the best diversity based method reduced only 7% annotation effort. In the simulated setting, AL methods, particularly uncertainty-sampling based approaches, seemed to significantly save annotation cost for the clinical NER task. The actual benefit of active learning in clinical NER should be further evaluated in a real-time setting. Copyright © 2015 Elsevier Inc. All rights reserved.

Negativity bias and task motivation: testing the effectiveness of positively versus negatively framed incentives.

PubMed

Goldsmith, Kelly; Dhar, Ravi

2013-12-01

People are frequently challenged by goals that demand effort and persistence. As a consequence, philosophers, psychologists, economists, and others have studied the factors that enhance task motivation. Using a sample of undergraduate students and a sample of working adults, we demonstrate that the manner in which an incentive is framed has implications for individuals' task motivation. In both samples we find that individuals are less motivated when an incentive is framed as a means to accrue a gain (positive framing) as compared with when the same incentive is framed as a means to avoid a loss (negative framing). Further, we provide evidence for the role of the negativity bias in this effect, and highlight specific populations for whom positive framing may be least motivating. Interestingly, we find that people's intuitions about when they will be more motivated show the opposite pattern, with people predicting that positively framed incentives will be more motivating than negatively framed incentives. We identify a lay belief in the positive correlation between enjoyment and task motivation as one possible factor contributing to the disparity between predicted and actual motivation as a result of the framing of the incentive. We conclude with a discussion of the managerial implications for these findings. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Practical limits on muscle synergy identification by non-negative matrix factorization in systems with mechanical constraints.

PubMed

Burkholder, Thomas J; van Antwerp, Keith W

2013-02-01

Statistical decomposition, including non-negative matrix factorization (NMF), is a convenient tool for identifying patterns of structured variability within behavioral motor programs, but it is unclear how the resolved factors relate to actual neural structures. Factors can be extracted from a uniformly sampled, low-dimension command space. In practical application, the command space is limited, either to those activations that perform some task(s) successfully or to activations induced in response to specific perturbations. NMF was applied to muscle activation patterns synthesized from low dimensional, synergy-like control modules mimicking simple task performance or feedback activation from proprioceptive signals. In the task-constrained paradigm, the accuracy of control module recovery was highly dependent on the sampled volume of control space, such that sampling even 50% of control space produced a substantial degradation in factor accuracy. In the feedback paradigm, NMF was not capable of extracting more than four control modules, even in a mechanical model with seven internal degrees of freedom. Reduced access to the low-dimensional control space imposed by physical constraints may result in substantial distortion of an existing low dimensional controller, such that neither the dimensionality nor the composition of the recovered/extracted factors match the original controller.

Aerobic Capacity and Cognitive Control in Elementary School-Age Children

PubMed Central

Scudder, Mark R.; Lambourne, Kate; Drollette, Eric S.; Herrmann, Stephen; Washburn, Richard; Donnelly, Joseph E.; Hillman, Charles H.

2014-01-01

Purpose The current study examined the relationship between children’s performance on the Progressive Aerobic Cardiovascular Endurance Run (PACER) subtest of the FitnessGram® and aspects of cognitive control that are believed to support academic success. Methods Hierarchical linear regression analyses were conducted on a sample of 2nd and 3rd grade children (n = 397) who completed modified versions of a flanker task and spatial n-back task to assess inhibitory control and working memory, respectively. Results Greater aerobic fitness was significantly related to shorter reaction time and superior accuracy during the flanker task, suggesting better inhibitory control and the facilitation of attention in higher fit children. A similar result was observed for the n-back task such that higher fit children exhibited more accurate target detection and discrimination performance when working memory demands were increased. Conclusion These findings support the positive association between aerobic fitness and multiple aspects of cognitive control in a large sample of children, using a widely implemented and reliable field estimate of aerobic capacity. Importantly, the current results suggest that this relationship is consistent across methods used to assess fitness, which may have important implications for extending this research to more representative samples of children in a variety of experimental contexts. PMID:24743109

The Effect of Asymmetrical Sample Training on Retention Functions for Hedonic Samples in Rats

ERIC Educational Resources Information Center

Simmons, Sabrina; Santi, Angelo

2012-01-01

Rats were trained in a symbolic delayed matching-to-sample task to discriminate sample stimuli that consisted of the presence of food or the absence of food. Asymmetrical sample training was provided in which one group was initially trained with only the food sample and the other group was initially trained with only the no-food sample. In…

Marijuana Primes, Marijuana Expectancies, and Arithmetic Efficiency*

PubMed Central

Hicks, Joshua A.; Pedersen, Sarah L.; McCarthy, Denis M.; Friedman, Ronald S.

2009-01-01

Objective: Previous research has shown that primes associated with alcohol influence behavior consistent with specific alcohol expectancies. The present study examined whether exposure to marijuana-related primes and marijuana expectancies interact to produce similar effects. Specifically, the present study examined whether marijuana primes and marijuana expectancies regarding cognitive and behavioral impairment interact to influence performance on an arithmetic task. Method: Two independent samples (N = 260) of undergraduate students (both marijuana users and nonusers) first completed measures of marijuana-outcome expectancies associated with cognitive and behavioral impairment and with general negative effects (Sample 2). Later in the semester, participants were exposed to marijuana-related (or neutral) primes and then completed an arithmetic task. Results: Results from Sample 1 indicated that participants who were exposed to marijuana-themed magazine covers performed more poorly on the arithmetic task if they expected that marijuana would lead to cognitive and behavioral impairment. Results from Sample 2 indicated that, for marijuana users, cognitive and behavioral impairment expectancies, but not expectancies regarding general negative effects, similarly moderated arithmetic performance for participants exposed to marijuana-related words. Conclusions: Results support the hypothesis that the implicit activation of specific marijuana-outcome expectancies can influence cognitive processes. Implications for research on marijuana are discussed. PMID:19371490

Influence of Procedural Learning on Iowa Gambling Task Performance Among HIV+ Individuals with History of Substance Dependence

PubMed Central

Gonzalez, Raul; Wardle, Margaret; Jacobus, Joanna; Vassileva, Jasmin; Martin-Thormeyer, Eileen M.

2010-01-01

HIV+ individuals have been shown to demonstrate deficits on the Iowa Gambling Task (IGT), a complex measure of “decision-making.” Little remains known about what other neurocognitive processes may account for variability in IGT performance among HIV+ samples or the role of procedural learning (PL) in IGT performance. A sample of 49 HIV+ individuals with a history of substance use disorders was examined to explore the relationship between IGT performance and three measures of PL: The Rotary Pursuit, Mirror Star Tracing, and Weather Prediction tasks. We found no statistically significant relationships between IGT performance and any of the PL tasks, despite finding significant correlations among the PL tasks. This pattern of results persisted when analyzing IGT performance in various ways (e.g., performance on earlier trial blocks or impairment classifications). Although other nondeclarative processes (e.g., somatic markers) may be important for IGT performance, these findings do not support PL as an important component neurocognitive process for the IGT. Similarly, these results suggest that differences in PL performance does not account for the decision-making deficits or variability in performances observed on the IGT among HIV+ individuals with a history of substance dependence. PMID:19939850

Biodynamic feedback training to assure learning partial load bearing on forearm crutches.

PubMed

Krause, Daniel; Wünnemann, Martin; Erlmann, Andre; Hölzchen, Timo; Mull, Melanie; Olivier, Norbert; Jöllenbeck, Thomas

2007-07-01

To examine how biodynamic feedback training affects the learning of prescribed partial load bearing (200N). Three pre-post experiments. Biomechanics laboratory in a German university. A volunteer sample of 98 uninjured subjects who had not used crutches recently. There were 24 subjects in experiment 1 (mean age, 23.2y); 64 in experiment 2 (mean age, 43.6y); and 10 in experiment 3 (mean age, 40.3y), parallelized by arm force. Video instruction and feedback training: In experiment 1, 2 varied instruction videos and reduced feedback frequency; in experiment 2, varied frequencies of changing tasks (contextual interference); and in experiment 3, feedback training (walking) and transfer (stair tasks). Vertical ground reaction force. Absolute error of practiced tasks was significantly reduced for all samples (P<.050). Varied contextual interference conditions did not significantly affect retention (P=.798) or transfer (P=.897). Positive transfer between tasks was significant in experiment 2 (P<.001) and was contrary to findings in experiment 3 (P=.071). Biodynamic feedback training is applicable for learning prescribed partial load bearing. The frequency of changing tasks is irrelevant. Despite some support for transfer effects, additional practice in climbing and descending stairs might be beneficial.

An exploratory study on the relationship between parents' passion for sport/exercise and children's self- and task-perceptions in sport/exercise.

PubMed

Chen, Chen-Yueh

2014-06-01

This study investigated the relationship between parents' passion for sport/exercise and children's self- and task-perceptions in sport and exercise. Paired samples of 312 children, 312 fathers, and 312 mothers were collected using two-stage sampling; parents were classified based on their passion for sport and exercise as high concordance if both parents had a high passion for sport and exercise, low concordance if neither parent had a passion for sport and exercise, or discordant. Intrinsic interest value, attainment value/importance, extrinsic utility value, ability/expectancy, task difficulty, and required effort were measured, as well as harmonious and obsessive passion. Children's self- and task-perceptions in sport and exercise were examined with respect to parents' passion for sport and exercise. The results of the study indicated that children of parents with high concordance in harmonious passion for sport and exercise scored higher on intrinsic interest value, attainment value/importance, extrinsic utility value, ability/expectancy, task difficulty, and required effort in sport and exercise than counterparts with discordant and low concordance parents. Similar patterns were found for obsessive passion in parents.

Using multivariate generalizability theory to assess the effect of content stratification on the reliability of a performance assessment.

PubMed

Keller, Lisa A; Clauser, Brian E; Swanson, David B

2010-12-01

In recent years, demand for performance assessments has continued to grow. However, performance assessments are notorious for lower reliability, and in particular, low reliability resulting from task specificity. Since reliability analyses typically treat the performance tasks as randomly sampled from an infinite universe of tasks, these estimates of reliability may not be accurate. For tests built according to a table of specifications, tasks are randomly sampled from different strata (content domains, skill areas, etc.). If these strata remain fixed in the test construction process, ignoring this stratification in the reliability analysis results in an underestimate of "parallel forms" reliability, and an overestimate of the person-by-task component. This research explores the effect of representing and misrepresenting the stratification appropriately in estimation of reliability and the standard error of measurement. Both multivariate and univariate generalizability studies are reported. Results indicate that the proper specification of the analytic design is essential in yielding the proper information both about the generalizability of the assessment and the standard error of measurement. Further, illustrative D studies present the effect under a variety of situations and test designs. Additional benefits of multivariate generalizability theory in test design and evaluation are also discussed.

Complexity quantification of dense array EEG using sample entropy analysis.

PubMed

Ramanand, Pravitha; Nampoori, V P N; Sreenivasan, R

2004-09-01

In this paper, a time series complexity analysis of dense array electroencephalogram signals is carried out using the recently introduced Sample Entropy (SampEn) measure. This statistic quantifies the regularity in signals recorded from systems that can vary from the purely deterministic to purely stochastic realm. The present analysis is conducted with an objective of gaining insight into complexity variations related to changing brain dynamics for EEG recorded from the three cases of passive, eyes closed condition, a mental arithmetic task and the same mental task carried out after a physical exertion task. It is observed that the statistic is a robust quantifier of complexity suited for short physiological signals such as the EEG and it points to the specific brain regions that exhibit lowered complexity during the mental task state as compared to a passive, relaxed state. In the case of mental tasks carried out before and after the performance of a physical exercise, the statistic can detect the variations brought in by the intermediate fatigue inducing exercise period. This enhances its utility in detecting subtle changes in the brain state that can find wider scope for applications in EEG based brain studies.

Italian version of the Task and Ego Orientation in physical education questionnaire.

PubMed

Bortoli, Laura; Robazza, Claudio

2005-12-01

The 1992 Task and Ego Orientation in Sport Questionnaire developed by Duda and Nicholls was modified by Walling and Duda in 1995 to assess task and ego orientation in physical education. The modified version was translated into Italian and administered to 1,547 students, 786 girls and 761 boys ages 14 to 19 years, to examine the factor structure. To evaluate the goodness of fit of the expected two-factor solution as in the original questionnaire, confirmatory factor analysis was conducted on four samples of boys and girls of two classes of age (14-16 and 17-19 years). Across sex and age, chi-squared/df ratios were less than 5.0, fit indices (GFI, NNFI, and CFI) not less than .90, and root mean square error of approximation (RMSEA) below .10. Thus, the two-factor solution of the questionnaire was supported. In the total sample, the two scales showed good internal consistency, with Cronbach alpha values of .92 for the Ego factor and .83 for the Task factor. The Ego factor accounted for 34.1% of variance and the Task factor accounted for 21.0% of variance.

Effects of a Supportive Audience on a Handgrip Squeezing Task in Adults

PubMed Central

LEITZELAR, BRIANNA N.; RAZON, SELEN; TOKAC, UMIT; DIERINGER, SHANNON; BOOK, CINDY; JUDGE, LAWRENCE W.

2016-01-01

The role of social facilitation by way of audience effect in select exercise-related variables during an isometric handgrip task was assessed using a mixed design. Fifty three moderately active participants (Mage= 21.76 ± 5.27) were recruited from the Midwestern United States. Participants were randomly assigned to one of two groups: supportive audience or control. Audience members provided positive verbal encouragement to participants in the experimental condition throughout the task performance. Participants in the control group performed the task in the absence of an audience and did not receive any verbal encouragement. Participants provided anxiety ratings pre- and post-task using the State-trait anxiety inventory for adults (STAI). Participants’ ratings of perceived exertion (RPE) and heart rate (HR) were monitored and assessed at 30-second intervals. Upon task completion, sustained effort in the form of time on task was recorded in seconds. A repeated measures analysis of variance (RM ANOVA) revealed that there was a time effect within groups of HR = ( F(2.64, 131.85) = 189.3, p <0.001) and within groups of RPE = (F(2.97, 139.42) = 2189.43 p <0.001). An independent sample T-test revealed significant differences in HR at 0, 30 and 60 seconds between the groups. An independent sample T-test revealed no significant differences in anxiety and RPE between the groups. These results partially support the notion of social facilitation and may have implications for research and practice. PMID:29399254

CLT and CLS job responsibilities: current distinctions and updates.

PubMed

Doig, K; Beck, S J; Kolenc, K

2001-01-01

This study was undertaken to address the following questions: 1. What tasks distinguish the job of a clinical laboratory scientist (CLS) from that of a clinical laboratory technician (CLT)? 2. What changes in role distinctions, have occurred for entry-level CLS and CLT practitioners over the five-year period 1993-98? 3. What tasks have been deleted from the CLT and CLS content outlines because they were not frequently performed or not considered entry-level? 4. What changes in practice are reflected in the current job analyses? A national job analysis of tasks constituting the job of clinical laboratory scientists (CLSs) and clinical laboratory technicians (CLTs) was conducted in 1998-99 as part of a standard setting process for the certifying examinations of the National Credentialing Agency for Laboratory Personnel (NCA). The job analyses relied upon mail surveys to 1200 individuals for each job level asking respondents to identify tasks significant to effective practice at job entry. The task lists resulting from statistical analysis of those surveys were examined to answer the study questions. The sample for each survey included 1200 practitioners, educators and laboratory managers selected at random from membership in professional organizations or from NCA certificant lists. Sampling was stratified to insure adequate practitioner representation. The mean rating on a four point scale for each item on the surveys was evaluated for overall significance as well as significance across geographic regions. The tasks meeting specified criteria were retained in the final task lists. Tasks were counted and their content evaluated to compare CLS and CLT job tasks. The response rates to the surveys were 33% for CLT and 21% for CLS. Reliability was judged based on average intraclass correlation coefficients of .86 and .82 for the CLT and CLS surveys, respectively. There were 952 tasks retained on the CLS content outline and 725 retained on the CLT content outline of the 1151 tasks on the original survey. Seven hundred and twenty two tasks were found on content outlines of both job levels, representing a 76% overlap. Tasks found only on the CLS outline included advanced technical tasks, a few management tasks, and more communication tasks. The jobs of CLS and CLT practitioners are distinct at job entry level with CLSs performing a broader array of technical and communication tasks as well as some management tasks. Though CLS staff uses few management skills at job entry, those tasks are performed by CLS staff in the laboratory and curricula must help prepare graduates for these tasks expected of experienced staff. CLTs perform tasks requiring problem solving and high level reasoning. CLT curricula must address the need for CLTs to perform these tasks.

A Contingency Model of Conflict and Team Effectiveness

ERIC Educational Resources Information Center

Shaw, Jason D.; Zhu, Jing; Duffy, Michelle K.; Scott, Kristin L.; Shih, Hsi-An; Susanto, Ely

2011-01-01

The authors develop and test theoretical extensions of the relationships of task conflict, relationship conflict, and 2 dimensions of team effectiveness (performance and team-member satisfaction) among 2 samples of work teams in Taiwan and Indonesia. Findings show that relationship conflict moderates the task conflict-team performance…

EMR Behavioral Curriculum and Student Record.

ERIC Educational Resources Information Center

Hartnett, John J.

Intended for use as a curriculum guide, a source for objectives for the individualized educational plan, and an evaluation instrument to measure handicapped students' learning, the guide lists sequences of developmental tasks. Tasks are outlined for primary, intermediate, and secondary levels in the following areas (sample subskills in…

American Indian Task Force Report.

ERIC Educational Resources Information Center

Mackey, John E., Ed.

Assuming that the client is central to any service program, the American Indian Task Force examined a national sample of "grass roots" social service organizations and/or individuals and schools of social work to determine the capability of providing relevant social work education to American Indians. Accordingly, the highest priorities…

A developmental neuroimaging investigation of the change paradigm

PubMed Central

Thomas, Laura A.; Hall, Julie M.; Skup, Martha; Jenkins, Sarah E.; Pine, Daniel S.; Leibenluft, Ellen

2010-01-01

This neuroimaging study examines the development of cognitive flexibility using the Change task in a sample of youths and adults. The Change task requires subjects to inhibit a prepotent response and substitute an alternate response, and the task incorporates an algorithm that adjusts task difficulty in response to subject performance. Data from both groups combined show a network of prefrontal and parietal areas that are active during the task. For adults vs. youths, a distributed network was more active for successful change trials versus go, baseline, or unsuccessful change trials. This network included areas involved in rule representation, retrieval (lateral PFC), and switching (medial PFC and parietal regions). These results are consistent with data from previous task-switching experiments and inform developmental understandings of cognitive flexibility. PMID:21159096

Connecting Research to Teaching: Using Data to Motivate the Use of Empirical Sampling Distributions

ERIC Educational Resources Information Center

Lee, Hollylynne S.; Starling, Tina T.; Gonzalez, Marggie D.

2014-01-01

Research shows that students often struggle with understanding empirical sampling distributions. Using hands-on and technology models and simulations of problems generated by real data help students begin to make connections between repeated sampling, sample size, distribution, variation, and center. A task to assist teachers in implementing…

Task conflicts and exclusive professionalism in nursing in South Korea.

PubMed

Jung, Minsoo

2014-01-01

Task conflicts among medical professions are essential problems to be solved in health care organizations. This study examined job conflicts between practical nurses (PNs) and registered nurses (RNs) in their duties and tasks with representative panelists from South Korea. This qualitative study used the Dacum Task Analysis process. Subject-matter experts in practical nursing were recruited utilizing stratified sampling: Ten experts developed job descriptions of PNs, and 20 validated the descriptions. The on-site tasks and duties of the PNs were measured by means of Dacum, and the results were reviewed by RNs using 3 focus-group interviews. The job description of PNs consisted of 10 duties and 117 tasks, overlapping with some tasks of RNs. Core tasks performed by PNs, such as invasive activities, led to task conflicts between the 2 groups, as these activities were regarded as the inherent duty of nursing professions. Thus, the RNs did not concede the expanded job scope of the PNs in terms of exclusive professionalism. To reduce task conflict, there is a need for the balanced development of nursing professionalism.

Observational Measures of Parenting in Anxious and Nonanxious Mothers: Does Type of Task Matter?

PubMed Central

Ginsburg, Golda S.; Grover, Rachel L.; Cord, Jennalee J.; Ialongo, Nick

2012-01-01

This study examined the relation between type of parent–child interaction task and parenting behaviors among a predominantly African American community-based sample. Twenty-five anxious and matched nonanxious (N = 50) mothers were videotaped with their children (Mage = 5.8 years) engaging in both a structured and unstructured task. Blind raters coded 3 parent behaviors hypothesized to play a role in the development of child anxiety: overcontrol, anxious behavior, and criticism. Results indicated that higher levels of overcontrol, anxious behavior, and criticism were found in the structured compared to unstructured task. Levels of criticism, among anxious mothers only, were significantly correlated across tasks. Results suggest that situation specific aspects of parent–child interaction tasks may influence parenting behaviors. These findings help explain variations in observational research in the anxiety literature and highlight the need for careful selection ofparent–child tasks in future research. PMID:16597228

Age-related decrements in dual-task performance: Comparison of different mobility and cognitive tasks. A cross sectional study

PubMed Central

Brustio, Paolo Riccardo; Zecca, Massimiliano; Rabaglietti, Emanuela; Liubicich, Monica Emma

2017-01-01

This cross-sectional study investigated the age-related differences in dual-task performance both in mobility and cognitive tasks and the additive dual-task costs in a sample of older, middle-aged and young adults. 74 older adults (M = 72.63±5.57 years), 58 middle-aged adults (M = 46.69±4.68 years) and 63 young adults (M = 25.34±3.00 years) participated in the study. Participants performed different mobility and subtraction tasks under both single- and dual-task conditions. Linear regressions, repeated-measures and one-way analyses of covariance were used, The results showed: significant effects of the age on the dual and mobility tasks (p<0.05) and differences among the age-groups in the combined dual-task costs (p<0.05); significant decreases in mobility performance under dual-task conditions in all groups (p<0.05) and a decrease in cognitive performance in the older group (p<0.05). Dual-task activity affected mobility and cognitive performance, especially in older adults who showed a higher dual-task cost, suggesting that dual-tasks activities are affected by the age and consequently also mobility and cognitive tasks are negatively influenced. PMID:28732080

Artistic Tasks Outperform Nonartistic Tasks for Stress Reduction

ERIC Educational Resources Information Center

Abbott, Kayleigh A.; Shanahan, Matthew J.; Neufeld, Richard W. J.

2013-01-01

Art making has been documented as an effective stress reduction technique. In this between-subjects experimental study, possible mechanisms of stress reduction were examined in a sample of 52 university students randomly assigned to one of four conditions generated by factorially crossing Activity Type (artistic or nonartistic) with Coping…

76 FR 66763 - Models for Plant-Specific Adoption of Technical Specifications Task Force Traveler TSTF-510...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-27

... of Technical Specifications Task Force Traveler TSTF-510, Revision 2, ``Revision to Steam Generator..., Revision 2, ``Revision to Steam Generator [(SG)] Program Inspection Frequencies and Tube Sample Selection..., ``Steam Generator (SG) Program,'' Specification 5.6.7, ``Steam Generator Tube Inspection Report,'' and the...

Task Characteristics, Managerial Socialization, and Media Selection.

ERIC Educational Resources Information Center

Donabedian, Bairj; McKinnon, Sharon M.; Bruns, William J., Jr.

1998-01-01

Questions why managers choose one communication medium in preference to another. Proposes a role for social factors in media selection. Finds, employing a large field-collected sample, strong support for Information Richness Theory, a rational-choice model connecting managers' media choice to task characteristics like variety and analyzability.…

Assessing Perspective Taking in Schizophrenia Using Relational Frame Theory

ERIC Educational Resources Information Center

Villatte, Matthieu; Monestes, Jean-Louis; McHugh, Louise; Freixa i Baque, Esteve; Loas, Gwenole

2010-01-01

The current study assessed deictic relational responding in people with schizophrenia. A perspective-taking task and a mental states attribution task were employed with a sample of 15 patients diagnosed with schizophrenia and 15 age-matched controls. Results revealed poorer performance of participants with schizophrenia in responding in accordance…

Impaired List Learning Is Not a General Property of Frontal Lesions

ERIC Educational Resources Information Center

Alexander, Michael P.; Stuss, Donald; Gillingham, Susan

2009-01-01

Background: List-learning tasks are frequently used to provide measures of "executive functions" that are believed necessary for successful memory performance. Small sample sizes, confounding anomia, and incomplete representation of all frontal regions have prevented consistent demonstration of distinct regional frontal effects on this task.…

Determining optimal parameters of the self-referent encoding task: A large-scale examination of self-referent cognition and depression.

PubMed

Dainer-Best, Justin; Lee, Hae Yeon; Shumake, Jason D; Yeager, David S; Beevers, Christopher G

2018-06-07

Although the self-referent encoding task (SRET) is commonly used to measure self-referent cognition in depression, many different SRET metrics can be obtained. The current study used best subsets regression with cross-validation and independent test samples to identify the SRET metrics most reliably associated with depression symptoms in three large samples: a college student sample (n = 572), a sample of adults from Amazon Mechanical Turk (n = 293), and an adolescent sample from a school field study (n = 408). Across all 3 samples, SRET metrics associated most strongly with depression severity included number of words endorsed as self-descriptive and rate of accumulation of information required to decide whether adjectives were self-descriptive (i.e., drift rate). These metrics had strong intratask and split-half reliability and high test-retest reliability across a 1-week period. Recall of SRET stimuli and traditional reaction time (RT) metrics were not robustly associated with depression severity. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Adaptive sampling of information in perceptual decision-making.

PubMed

Cassey, Thomas C; Evens, David R; Bogacz, Rafal; Marshall, James A R; Ludwig, Casimir J H

2013-01-01

In many perceptual and cognitive decision-making problems, humans sample multiple noisy information sources serially, and integrate the sampled information to make an overall decision. We derive the optimal decision procedure for two-alternative choice tasks in which the different options are sampled one at a time, sources vary in the quality of the information they provide, and the available time is fixed. To maximize accuracy, the optimal observer allocates time to sampling different information sources in proportion to their noise levels. We tested human observers in a corresponding perceptual decision-making task. Observers compared the direction of two random dot motion patterns that were triggered only when fixated. Observers allocated more time to the noisier pattern, in a manner that correlated with their sensory uncertainty about the direction of the patterns. There were several differences between the optimal observer predictions and human behaviour. These differences point to a number of other factors, beyond the quality of the currently available sources of information, that influences the sampling strategy.

Effects of System Timing Parameters on Operator Performance in a Personnel Records Task

DTIC Science & Technology

1981-03-01

work sampling, embedded performance measures, and operator satisfaction ratings) are needed to provide a complete analysis of the effects of the four...HFL-8 l-l/NPRDC-8 1-1 March 1981 EFFECTS OF SYSTEM TIMING PARAMETERS ON OPERATOR PERFORMANCE IN A PERSONNEL RECORDS TASK Robert C. Williges Beverly H...and Subtitle) S. TYPE OF REPORT & PERIOD COVERED EFFECTS OF SYSTEM TIMING PARAMETERS ON OPERATOR PERFORMANCE IN A PERSONNEL RECORDS TASK Final

Children's mental time travel during mind wandering.

PubMed

Ye, Qun; Song, Xiaolan; Zhang, Yi; Wang, Qinqin

2014-01-01

The prospective bias is a salient feature of mind wandering in healthy adults, yet little is known about the temporal focus of children's mind wandering. In the present study, (I) we developed the temporal focus of mind wandering questionnaire for school-age children (TFMWQ-C), a 12-item scale with good test-retest reliability and construct validity. (II) The criterion validity was tested by thought sampling in both choice reaction time task and working memory task. A positive correlation was found between the temporal focus measured by the questionnaire and the one adopted during task-unrelated thoughts (TUTs) by thought sampling probes, especially in the trait level of future-oriented mind wandering. At the same time, children who experienced more TUTs tended to show worse behavioral performance during tasks. (III) The children in both tasks experienced more future-oriented TUTs than past-oriented ones, which was congruent with the results observed in adults; however, in contrast with previous research on adults, the prospective bias was not influenced by task demands. Together these results indicate that the prospective bias of mind wandering has emerged since the school-age (9∼13 years old), and that the relationship between mental time travel (MTT) during mind wandering and the use of cognitive resources differs between children and adults. Our study provides new insights into how this interesting feature of mind wandering may adaptively contribute to the development of children's MTT.

Monkeys rely on recency of stimulus repetition when solving short-term memory tasks.

PubMed

Wittig, John H; Richmond, Barry J

2014-05-16

Seven monkeys performed variants of two short-term memory tasks that others have used to differentiate between selective and nonselective memory mechanisms. The first task was to view a list of sequentially presented images and identify whether a test matched any image from the list, but not a distractor from a preceding list. Performance was best when the test matched the most recently presented image. Response rates depended linearly on recency of repetition whether the test matched a sample from the current list or a distractor from a preceding list, suggesting nonselective memorization of all images viewed instead of just the sample images. The second task was to remember just the first image in a list selectively and ignore subsequent distractors. False alarms occurred frequently when the test matched a distractor presented near the beginning of the sequence. In a pilot experiment, response rates depended linearly on recency of repetition irrespective of whether the test matched the first image or a distractor, again suggesting nonselective memorization of all images instead of just the first image. Modification of the second task improved recognition of the first image, but did not abolish use of recency. Monkeys appear to perform nonspatial visual short-term memory tasks often (or exclusively) using a single, nonselective, memory mechanism that conveys the recency of stimulus repetition. Published by Cold Spring Harbor Laboratory Press.

Developing a hippocampal neural prosthetic to facilitate human memory encoding and recall.

PubMed

Hampson, Robert E; Song, Dong; Robinson, Brian S; Fetterhoff, Dustin; Dakos, Alexander S; Roeder, Brent M; She, Xiwei; Wicks, Robert T; Witcher, Mark R; Couture, Daniel E; Laxton, Adrian W; Munger-Clary, Heidi; Popli, Gautam; Sollman, Myriam J; Whitlow, Christopher T; Marmarelis, Vasilis Z; Berger, Theodore W; Deadwyler, Sam A

2018-06-01

We demonstrate here the first successful implementation in humans of a proof-of-concept system for restoring and improving memory function via facilitation of memory encoding using the patient's own hippocampal spatiotemporal neural codes for memory. Memory in humans is subject to disruption by drugs, disease and brain injury, yet previous attempts to restore or rescue memory function in humans typically involved only nonspecific, modulation of brain areas and neural systems related to memory retrieval. We have constructed a model of processes by which the hippocampus encodes memory items via spatiotemporal firing of neural ensembles that underlie the successful encoding of short-term memory. A nonlinear multi-input, multi-output (MIMO) model of hippocampal CA3 and CA1 neural firing is computed that predicts activation patterns of CA1 neurons during the encoding (sample) phase of a delayed match-to-sample (DMS) human short-term memory task. MIMO model-derived electrical stimulation delivered to the same CA1 locations during the sample phase of DMS trials facilitated short-term/working memory by 37% during the task. Longer term memory retention was also tested in the same human subjects with a delayed recognition (DR) task that utilized images from the DMS task, along with images that were not from the task. Across the subjects, the stimulated trials exhibited significant improvement (35%) in both short-term and long-term retention of visual information. These results demonstrate the facilitation of memory encoding which is an important feature for the construction of an implantable neural prosthetic to improve human memory.

Developing a hippocampal neural prosthetic to facilitate human memory encoding and recall

NASA Astrophysics Data System (ADS)

Hampson, Robert E.; Song, Dong; Robinson, Brian S.; Fetterhoff, Dustin; Dakos, Alexander S.; Roeder, Brent M.; She, Xiwei; Wicks, Robert T.; Witcher, Mark R.; Couture, Daniel E.; Laxton, Adrian W.; Munger-Clary, Heidi; Popli, Gautam; Sollman, Myriam J.; Whitlow, Christopher T.; Marmarelis, Vasilis Z.; Berger, Theodore W.; Deadwyler, Sam A.

2018-06-01

Objective. We demonstrate here the first successful implementation in humans of a proof-of-concept system for restoring and improving memory function via facilitation of memory encoding using the patient’s own hippocampal spatiotemporal neural codes for memory. Memory in humans is subject to disruption by drugs, disease and brain injury, yet previous attempts to restore or rescue memory function in humans typically involved only nonspecific, modulation of brain areas and neural systems related to memory retrieval. Approach. We have constructed a model of processes by which the hippocampus encodes memory items via spatiotemporal firing of neural ensembles that underlie the successful encoding of short-term memory. A nonlinear multi-input, multi-output (MIMO) model of hippocampal CA3 and CA1 neural firing is computed that predicts activation patterns of CA1 neurons during the encoding (sample) phase of a delayed match-to-sample (DMS) human short-term memory task. Main results. MIMO model-derived electrical stimulation delivered to the same CA1 locations during the sample phase of DMS trials facilitated short-term/working memory by 37% during the task. Longer term memory retention was also tested in the same human subjects with a delayed recognition (DR) task that utilized images from the DMS task, along with images that were not from the task. Across the subjects, the stimulated trials exhibited significant improvement (35%) in both short-term and long-term retention of visual information. Significance. These results demonstrate the facilitation of memory encoding which is an important feature for the construction of an implantable neural prosthetic to improve human memory.

Surface Sampling and Detection Investigations at the CDC

NASA Astrophysics Data System (ADS)

Rose, L. J.; Coulliette, A. D.

2015-03-01

The Environmental and Applied Microbiology Team is tasked with investigating disease outbreaks in healthcare settings. We will summarize and discuss applied research endeavors to understand and optimize sampling and detection of microorganisms.

Multisensory information boosts numerical matching abilities in young children.

PubMed

Jordan, Kerry E; Baker, Joseph

2011-03-01

This study presents the first evidence that preschool children perform more accurately in a numerical matching task when given multisensory rather than unisensory information about number. Three- to 5-year-old children learned to play a numerical matching game on a touchscreen computer, which asked them to match a sample numerosity with a numerically equivalent choice numerosity. Samples consisted of a series of visual squares on some trials, a series of auditory tones on other trials, and synchronized squares and tones on still other trials. Children performed at chance on this matching task when provided with either type of unisensory sample, but improved significantly when provided with multisensory samples. There was no speed–accuracy tradeoff between unisensory and multisensory trial types. Thus, these findings suggest that intersensory redundancy may improve young children’s abilities to match numerosities.

A Blueprint for Demonstrating Quantum Supremacy with Superconducting Qubits

NASA Technical Reports Server (NTRS)

Kechedzhi, Kostyantyn

2018-01-01

Long coherence times and high fidelity control recently achieved in scalable superconducting circuits paved the way for the growing number of experimental studies of many-qubit quantum coherent phenomena in these devices. Albeit full implementation of quantum error correction and fault tolerant quantum computation remains a challenge the near term pre-error correction devices could allow new fundamental experiments despite inevitable accumulation of errors. One such open question foundational for quantum computing is achieving the so called quantum supremacy, an experimental demonstration of a computational task that takes polynomial time on the quantum computer whereas the best classical algorithm would require exponential time and/or resources. It is possible to formulate such a task for a quantum computer consisting of less than a 100 qubits. The computational task we consider is to provide approximate samples from a non-trivial quantum distribution. This is a generalization for the case of superconducting circuits of ideas behind boson sampling protocol for quantum optics introduced by Arkhipov and Aaronson. In this presentation we discuss a proof-of-principle demonstration of such a sampling task on a 9-qubit chain of superconducting gmon qubits developed by Google. We discuss theoretical analysis of the driven evolution of the device resulting in output approximating samples from a uniform distribution in the Hilbert space, a quantum chaotic state. We analyze quantum chaotic characteristics of the output of the circuit and the time required to generate a sufficiently complex quantum distribution. We demonstrate that the classical simulation of the sampling output requires exponential resources by connecting the task of calculating the output amplitudes to the sign problem of the Quantum Monte Carlo method. We also discuss the detailed theoretical modeling required to achieve high fidelity control and calibration of the multi-qubit unitary evolution in the device. We use a novel cross-entropy statistical metric as a figure of merit to verify the output and calibrate the device controls. Finally, we demonstrate the statistics of the wave function amplitudes generated on the 9-gmon chain and verify the quantum chaotic nature of the generated quantum distribution. This verifies the implementation of the quantum supremacy protocol.

The evaluation and quantification of respirable coal and silica dust concentrations: a task-based approach.

PubMed

Grové, T; Van Dyk, T; Franken, A; Du Plessis, J

2014-01-01

Silicosis and coal worker's pneumoconiosis are serious occupational respiratory diseases associated with the coal mining industry and the inhalation of respirable dusts containing crystalline silica. The purpose of this study (funded by the Mine Health and Safety Council of South Africa) was to evaluate the individual contributions of underground coal mining tasks to the respirable dust and respirable silica dust concentrations in an underground section by sampling the respirable dust concentrations at the intake and return of each task. The identified tasks were continuous miner (CM) cutting, construction, transfer of coal, tipping, and roof bolting. The respirable dust-generating hierarchy of the tasks from highest to lowest was: transfer of coal > CM right cutting > CM left cutting > CM face cutting > construction > roof bolting > tipping; and for respirable silica dust: CM left cutting > construction > transfer of coal > CM right cutting. Personal exposure levels were determined by sampling the exposures of workers performing tasks in the section. Respirable dust concentrations and low concentrations of respirable silica dust were found at the intake air side of the section, indicating that air entering the section is already contaminated. The hierarchy for personal respirable dust exposures was as follows, from highest to lowest: CM operator > cable handler > miner > roof bolt operator > shuttle car operator, and for respirable silica dust: shuttle car operator > CM operator > cable handler > roof bolt operator > miner. Dust control methods to lower exposures should include revision of the position of workers with regard to the task performed, positioning of the tasks with regard to the CM cutting, and proper use of the line curtains to direct ventilation appropriately. The correct use of respiratory protection should also be encouraged.

The cortisol awakening response is associated with performance of a serial sequence reaction time task.

PubMed

Hodyl, Nicolette A; Schneider, Luke; Vallence, Ann-Maree; Clow, Angela; Ridding, Michael C; Pitcher, Julia B

2016-02-01

There is emerging evidence of a relationship between the cortisol awakening response (CAR) and the neural mechanisms underlying learning and memory. The aim of this study was to determine whether the CAR is associated with acquisition, retention and overnight consolidation or improvement of a serial sequence reaction time task. Salivary samples were collected at 0, 15, 30 and 45 min after awakening in 39 healthy adults on 2 consecutive days. The serial sequence reaction time task was repeated each afternoon. Participants completed the perceived stress scale and provided salivary samples prior to testing for cortisol assessment. While the magnitude of the CAR (Z score) was not associated with either baseline performance or the timed improvement during task acquisition of the serial sequence task, a positive correlation was observed with reaction times during the stable performance phase on day 1 (r=0.373, p=0.019). Residuals derived from the relationship between baseline and stable phase reaction times on day 1 were used as a surrogate for the degree of learning: these residuals were also correlated with the CAR mean increase on day 1 (r=0.357, p=0.048). Task performance on day 2 was not associated with the CAR obtained on this same day. No association was observed between the perceived stress score, cortisol at testing or task performance. These data indicate that a smaller CAR in healthy adults is associated with a greater degree of learning and faster performance of a serial sequence reaction time task. These results support recognition of the CAR as an important factor contributing to cognitive performance throughout the day. Copyright © 2015 Elsevier B.V. All rights reserved.

Effects of gender and executive function on visuospatial working memory in adult obsessive-compulsive disorder.

PubMed

Martoni, Riccardo Maria; Salgari, Giulia; Galimberti, Elisa; Cavallini, Maria Cristina; O'Neill, Joseph

2015-12-01

Visuospatial working memory (VSWM) is the ability of the brain to transiently store and manipulate visual information. VSWM deficiencies have been reported in obsessive-compulsive disorder (OCD), but not consistently, perhaps due to variability in task design and clinical patient factors. To explore this variability, this study assessed effects of the design factors task difficulty and executive organizational strategy and of the clinical factors gender, OCD symptom dimension, and duration of illness on VSWM in OCD. The CANTAB spatial working memory, spatial recognition memory, delayed matching to sample, and stop signal tasks were administered to 42 adult OCD patients and 42 age- and sex-matched healthy controls. Aims were to detect a possible VSWM deficit in the OCD sample, to evaluate influences of the above task and patient factors, to determine the specificity of the deficit to the visuospatial subdomain, and to examine effects of sustained attention as potential neurocognitive confound. We confirmed previous findings of a VSWM deficit in OCD that was more severe for greater memory load (task difficulty) and that was affected by task strategy (executive function). We failed to demonstrate significant deficits in neighboring or confounding neurocognitive subdomains (visual object recognition or visual object short-term memory, sustained attention). Notably, the VSWM deficit was only significant for female patients, adding to evidence for sexual dimorphism in OCD. Again as in prior work, more severe OCD symptoms in the symmetry dimension (but no other dimension) significantly negatively impacted VSWM. Duration of illness had no significant effect on VSWM. VSWM deficits in OCD appear more severe with higher task load and may be mediated through poor task strategy. Such deficits may present mainly in female patients and in (male and female) patients with symmetry symptoms.

Robust gene selection methods using weighting schemes for microarray data analysis.

PubMed

Kang, Suyeon; Song, Jongwoo

2017-09-02

A common task in microarray data analysis is to identify informative genes that are differentially expressed between two different states. Owing to the high-dimensional nature of microarray data, identification of significant genes has been essential in analyzing the data. However, the performances of many gene selection techniques are highly dependent on the experimental conditions, such as the presence of measurement error or a limited number of sample replicates. We have proposed new filter-based gene selection techniques, by applying a simple modification to significance analysis of microarrays (SAM). To prove the effectiveness of the proposed method, we considered a series of synthetic datasets with different noise levels and sample sizes along with two real datasets. The following findings were made. First, our proposed methods outperform conventional methods for all simulation set-ups. In particular, our methods are much better when the given data are noisy and sample size is small. They showed relatively robust performance regardless of noise level and sample size, whereas the performance of SAM became significantly worse as the noise level became high or sample size decreased. When sufficient sample replicates were available, SAM and our methods showed similar performance. Finally, our proposed methods are competitive with traditional methods in classification tasks for microarrays. The results of simulation study and real data analysis have demonstrated that our proposed methods are effective for detecting significant genes and classification tasks, especially when the given data are noisy or have few sample replicates. By employing weighting schemes, we can obtain robust and reliable results for microarray data analysis.

Distributed encoding of spatial and object categories in primate hippocampal microcircuits

PubMed Central

Opris, Ioan; Santos, Lucas M.; Gerhardt, Greg A.; Song, Dong; Berger, Theodore W.; Hampson, Robert E.; Deadwyler, Sam A.

2015-01-01

The primate hippocampus plays critical roles in the encoding, representation, categorization and retrieval of cognitive information. Such cognitive abilities may use the transformational input-output properties of hippocampal laminar microcircuitry to generate spatial representations and to categorize features of objects, images, and their numeric characteristics. Four nonhuman primates were trained in a delayed-match-to-sample (DMS) task while multi-neuron activity was simultaneously recorded from the CA1 and CA3 hippocampal cell fields. The results show differential encoding of spatial location and categorization of images presented as relevant stimuli in the task. Individual hippocampal cells encoded visual stimuli only on specific types of trials in which retention of either, the Sample image, or the spatial position of the Sample image indicated at the beginning of the trial, was required. Consistent with such encoding, it was shown that patterned microstimulation applied during Sample image presentation facilitated selection of either Sample image spatial locations or types of images, during the Match phase of the task. These findings support the existence of specific codes for spatial and numeric object representations in primate hippocampus which can be applied on differentially signaled trials. Moreover, the transformational properties of hippocampal microcircuitry, together with the patterned microstimulation are supporting the practical importance of this approach for cognitive enhancement and rehabilitation, needed for memory neuroprosthetics. PMID:26500473

Silica dust exposures during selected construction activities.

PubMed

Flanagan, Mary Ellen; Seixas, Noah; Majar, Maria; Camp, Janice; Morgan, Michael

2003-01-01

This study characterized exposure for dust-producing construction tasks. Eight common construction tasks were evaluated for quartz and respirable dust exposure by collecting 113 personal task period samples for cleanup; demolition with handheld tools; concrete cutting; concrete mixing; tuck-point grinding; surface grinding; sacking and patching concrete; and concrete floor sanding using both time-integrating filter samples and direct-reading respirable dust monitors. The geometric mean quartz concentration was 0.10 mg/m(3) (geometric standard deviation [GSD]=4.88) for all run time samples, with 71% exceeding the threshold limit value. Activities with the highest exposures were surface grinding, tuck-point grinding, and concrete demolition (GM[GSD] of 0.63[4.12], 0.22[1.94], and 0.10[2.60], respectively). Factors recorded each minute were task, tool, work area, respiratory protection and controls used, estimated cross draft, and whether anyone nearby was making dust. Factors important to exposure included tool used, work area configuration, controls employed, cross draft, and in some cases nearby dust. More protective respirators were employed as quartz concentration increased, although respiratory protection was found to be inadequate for 42% of exposures. Controls were employed for only 12% of samples. Exposures were reduced with three controls: box fan for surface grinding and floor sanding, and vacuum/shroud for surface grinding, with reductions of 57, 50, and 71%, respectively. Exposures were higher for sweeping compound, box fan for cleanup, ducted fan dilution, and wetted substrate. Construction masons and laborers are frequently overexposed to silica. The usual protection method, respirators, was not always adequate, and engineering control use was infrequent and often ineffective.

The application of subjective job task analysis techniques in physically demanding occupations: evidence for the presence of self-serving bias.

PubMed

Lee-Bates, Benjamin; Billing, Daniel C; Caputi, Peter; Carstairs, Greg L; Linnane, Denise; Middleton, Kane

2017-09-01

The aim of this study was to determine if perceptions of physically demanding job tasks are biased by employee demographics and employment profile characteristics including: age, sex, experience, length of tenure, rank and if they completed or supervised a task. Surveys were administered to 427 Royal Australian Navy personnel who characterised 33 tasks in terms of physical effort, importance, frequency, duration and vertical/horizontal distance travelled. Results showed no evidence of bias resulting from participant characteristics, however participants who were actively involved in both task participation and supervision rated these tasks as more important than those involved only in the supervision of that task. This may indicate self-serving bias in which participants that are more actively involved in a task had an inflated perception of that task's importance. These results have important implications for the conduct of job task analyses, especially the use of subjective methodologies in the development of scientifically defensible physical employment standards. Practitioner Summary: To examine the presence of systematic bias in subjective job task analysis methodologies, a survey was conducted on a sample of Royal Australian Navy personnel. The relationship between job task descriptions and participant's demographic and job profile characteristics revealed the presence of self-serving bias affecting perceptions of task importance.

The composite complex span: French validation of a short working memory task.

PubMed

Gonthier, Corentin; Thomassin, Noémylle; Roulin, Jean-Luc

2016-03-01

Most studies in individual differences in the field of working memory research use complex span tasks to measure working memory capacity. Various complex span tasks based on different materials have been developed, and these tasks have proven both reliable and valid; several complex span tasks are often combined to provide a domain-general estimate of working memory capacity with even better psychometric properties. The present work sought to address two issues. Firstly, having participants perform several full-length complex span tasks in succession makes for a long and tedious procedure. Secondly, few complex span tasks have been translated and validated in French. We constructed a French working memory task labeled the Composite Complex Span (CCS). The CCS includes shortened versions of three classic complex span tasks: the reading span, symmetry span, and operation span. We assessed the psychometric properties of the CCS, including test-retest reliability and convergent validity, with Raven's Advanced Progressive Matrices and with an alpha span task; the CCS demonstrated satisfying qualities in a sample of 1,093 participants. This work provides evidence that shorter versions of classic complex span tasks can yield valid working memory estimates. The materials and normative data for the CCS are also included.

A visual processing advantage for young-adolescent deaf observers: Evidence from face and object matching tasks

PubMed Central

Megreya, Ahmed M.; Bindemann, Markus

2017-01-01

It is unresolved whether the permanent auditory deprivation that deaf people experience leads to the enhanced visual processing of faces. The current study explored this question with a matching task in which observers searched for a target face among a concurrent lineup of ten faces. This was compared with a control task in which the same stimuli were presented upside down, to disrupt typical face processing, and an object matching task. A sample of young-adolescent deaf observers performed with higher accuracy than hearing controls across all of these tasks. These results clarify previous findings and provide evidence for a general visual processing advantage in deaf observers rather than a face-specific effect. PMID:28117407

Improving the effectiveness of performance feedback by considering personality traits and task demands

PubMed Central

Peterson, Jordan B.

2018-01-01

Although performance feedback is widely employed as a means to improve motivation, the efficacy and reliability of performance feedback is often obscured by individual differences and situational variables. The joint role of these moderating variables remains unknown. Accordingly, we investigate how the motivational impact of feedback is moderated by personality and task-difficulty. Utilizing three samples (total N = 916), we explore how Big Five personality traits moderate the motivational impact of false positive and negative feedback on playful, neutral, and frustrating puzzle tasks, respectively. Conscientious and Neurotic individuals together appear particularly sensitive to task difficulty, becoming significantly more motivated by negative feedback on playful tasks and demotivated by negative feedback on frustrating tasks. Results are discussed in terms of Goal-Setting and Self Determination Theory. Implications for industry and education are considered. PMID:29787593

Does children's moral compass waver under social pressure? Using the conformity paradigm to test preschoolers' moral and social-conventional judgments.

PubMed

Kim, Elizabeth B; Chen, Chuansheng; Smetana, Judith G; Greenberger, Ellen

2016-10-01

The current study tested whether preschoolers' moral and social-conventional judgments change under social pressure using Asch's conformity paradigm. A sample of 132 preschoolers (Mage=3.83years, SD=0.85) rated the acceptability of moral and social-conventional events and also completed a visual judgment task (i.e., comparing line length) both independently and after having viewed two peers who consistently made immoral, unconventional, or visually inaccurate judgments. Results showed evidence of conformity on all three tasks, but conformity was stronger on the social-conventional task than on the moral and visual tasks. Older children were less susceptible to pressure for social conformity for the moral and visual tasks but not for the conventional task. Copyright © 2016 Elsevier Inc. All rights reserved.

Similarity in functional brain architecture between rest and specific task modes: A model of genetic and environmental contributions to episodic memory.

PubMed

Petrican, Raluca; Levine, Brian T

2018-06-21

The ability to keep a mental record of specific past events, dubbed episodic memory (EM), is key to lifespan adaptation. Nonetheless, the neural mechanisms underlying its typical inter-individual variability remain poorly understood. To address this issue, we tested whether individual differences in EM could be predicted from levels of functional brain re-organization between rest and task modes relevant to the transformation of perceptual information into mental representations (relational processing, meaning extraction, online maintenance versus updating of bound perceptual features). To probe the trait specificity of our model, we included three additional core mental functions, processing speed, abstract reasoning, and cognitive control. Finally, we investigated the extent to which our proposed model reflected genetic versus environmental contributions to EM variability. Hypotheses were tested by applying graph theoretical analysis and structural equation modeling to resting state and task fMRI data from two samples of participants in the Human Connectome Project (Sample 1: N = 338 unrelated individuals; Sample 2: N = 268 monozygotic vs. dizygotic twins [134 same-sex pairs]). Levels of functional brain reorganization between rest and the scrutinized task modes, particularly relational processing and online maintenance of bound perceptual features, contributed substantially to variations in both EM and abstract reasoning (but not in cognitive control or processing speed) among the younger adults in our sample, implying a substantial neurofunctional overlap, at least during this life stage. Similarity in functional organization between rest and each of the scrutinized task modes drew on distinguishable neural resources and showed differential susceptibility to genetic versus environmental influences. Our results suggest that variability on complex traits, such as EM, is supported by neural mechanisms comprising multiple components, each reflecting a distinct pattern of genetic versus environmental contributions and whose relative importance may vary across typical versus psychopathological development. Copyright © 2018. Published by Elsevier Inc.

Executive functions, information sampling, and decision making in narcolepsy with cataplexy.

PubMed

Delazer, Margarete; Högl, Birgit; Zamarian, Laura; Wenter, Johanna; Gschliesser, Viola; Ehrmann, Laura; Brandauer, Elisabeth; Cevikkol, Zehra; Frauscher, Birgit

2011-07-01

Narcolepsy with cataplexy (NC) affects neurotransmitter systems regulating emotions and cognitive functions. This study aimed to assess executive functions, information sampling, reward processing, and decision making in NC. Twenty-one NC patients and 58 healthy participants performed an extensive neuropsychological test battery. NC patients scored as controls in executive function tasks assessing set shifting, reversal learning, working memory, and planning. Group differences appeared in a task measuring information sampling and reward sensitivity. NC patients gathered less information, tolerated a higher level of uncertainty, and were less influenced by reward contingencies than controls. NC patients also showed reduced learning in decision making and had significantly lower scores than controls in the fifth block of the IOWA gambling task. No correlations were found with measures of sleepiness. NC patients may achieve high performance in several neuropsychological domains, including executive functions. Specific differences between NC patients and controls highlight the importance of the hypocretin system in reward processing and decision making and are in line with previous neuroimaging and neurophysiological studies. PsycINFO Database Record (c) 2011 APA, all rights reserved.

Individual differences in components of impulsivity and effortful control moderate the relation between borderline personality disorder traits and emotion recognition in a sample of university students.

PubMed

Preti, Emanuele; Richetin, Juliette; Suttora, Chiara; Pisani, Alberto

2016-04-30

Dysfunctions in social cognition characterize personality disorders. However, mixed results emerged from literature on emotion processing. Borderline Personality Disorder (BPD) traits are either associated with enhanced emotion recognition, impairments, or equal functioning compared to controls. These apparent contradictions might result from the complexity of emotion recognition tasks used and from individual differences in impulsivity and effortful control. We conducted a study in a sample of undergraduate students (n=80), assessing BPD traits, using an emotion recognition task that requires the processing of only visual information or both visual and acoustic information. We also measured individual differences in impulsivity and effortful control. Results demonstrated the moderating role of some components of impulsivity and effortful control on the capability of BPD traits in predicting anger and happiness recognition. We organized the discussion around the interaction between different components of regulatory functioning and task complexity for a better understanding of emotion recognition in BPD samples. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Unintended activity in homologous muscle during intended unilateral contractions increases with greater task difficulty.

PubMed

Watanabe, Hironori; Kanehisa, Hiroaki; Yoshitake, Yasuhide

2017-10-01

The present study aimed to examine (1) the effect of task difficulty on unintended muscle activation (UIMA) levels in contralateral homologous muscle, (2) the difference between young and old adults in degree of UIMA with respect to task difficulty, and (3) temporal correlations between intended and contralateral unintended muscle activity at low frequency during unilateral intended force-matching tasks. Twelve young (21.8 ± 2.4 years) and twelve old (69.9 ± 5.3 years) adult men performed steady isometric abductions with the left index finger at 20-80% of maximal voluntary contraction force. Two task difficulties were set by adjusting the spacing between two bars centered about the target force used for visual feedback on a monitor. The amplitude of surface electromyogram (aEMG) for both hands was calculated and normalized with respect to the maximal value. To determine if oscillations between intended and unintended muscle activities were correlated, cross-correlation function (CCF) of rectified EMG for both hands at low frequency was calculated for samples deemed adequate. The unintended aEMG (right hand) had significant main effects in task difficulty, age, and target force (all P < 0.05) without any interactions. Distinct significant peaks in CCF (0.38 on average, P < 0.05) with small time lags were present between rectified EMGs of intended and unintended muscles in 14 of the 17 samples. The current results indicate that UIMA increases with greater task difficulty regardless of age, and temporal correlations exist between intended and contralateral unintended muscle activities at low frequency.

Emergent, untrained stimulus relations in many-to-one matching-to-sample discriminations in rats.

PubMed

Nakagawa, Esho

2005-03-01

The present experiment investigated whether rats formed emergent, untrained stimulus relations in many-to-one matching-to-sample discriminations. In Phase 1, rats were trained to match two samples (triangle and horizontal stripes) to a common comparison (horizontal stripes) and two additional samples (circle or vertical stripes) to another comparison (vertical stripes). Then, in Phase 2, the rats were trained to match the one sample (triangle) to a new comparison (black) and the other sample (circle) to another comparison (white). In the Phase 3 test, half the rats (consistent group) were given two new tasks in which the sample-correct comparison relation was consistent with any emergent stimulus relations that previously may have been learned. The remaining 6 rats (inconsistent group) were given two new tasks in which the sample-correct comparison relation was not consistent with any previously learned emergent stimulus relations. Rats in the consistent group showed more accurate performance at the start of Phase 3, and faster learning to criterion in this phase, as compared with rats in the inconsistent group. This finding suggests that rats may form emergent, untrained stimulus relations between the discriminative stimuli in many-to-one matching-to-sample discriminations.

Test and evaluation of the Argonne BPAC10 Series air chamber calorimeter designed for 20 minute measurements

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

Perry, R.B.; Fiarman, S.; Jung, E.A.

1990-10-01

This paper is the final report on DOE-OSS Task ANLE88002 Fast Air Chamber Calorimetry.'' The task objective was to design, construct, and test an isothermal air chamber calorimeter for plutonium assay of bulk samples that would meet the following requirements for sample power measurement: average sample measurement time less than 20 minutes. Measurement of samples with power output up to 10 W. Precision of better than 1% RSD for sample power greater than 1 W. Precision better than 0.010 watt SD, for sample power less than 1 W. This report gives a description of the calorimeter hardware and software andmore » discusses the test results. The instrument operating procedure, included as an appendix, gives examples of typical input/output and explains the menu driven software. Sample measurement time of less than 20 minutes was attained by pre-equilibration of the samples in low cost precision preheaters and by prediction of equilibrium measurements. Tests at the TA55 Plutonium Facility at Los Alamos National Laboratory, on typical samples, indicates that the instrument meets all the measurement requirements.« less

Beads task vs. box task: The specificity of the jumping to conclusions bias.

PubMed

Balzan, Ryan P; Ephraums, Rachel; Delfabbro, Paul; Andreou, Christina

2017-09-01

Previous research involving the probabilistic reasoning 'beads task' has consistently demonstrated a jumping-to-conclusions (JTC) bias, where individuals with delusions make decisions based on limited evidence. However, recent studies have suggested that miscomprehension may be confounding the beads task. The current study aimed to test the conventional beads task against a conceptually simpler probabilistic reasoning "box task" METHODS: One hundred non-clinical participants completed both the beads task and the box task, and the Peters et al. Delusions Inventory (PDI) to assess for delusion-proneness. The number of 'draws to decision' was assessed for both tasks. Additionally, the total amount of on-screen evidence was manipulated for the box task, and two new box task measures were assessed (i.e., 'proportion of evidence requested' and 'deviation from optimal solution'). Despite being conceptually similar, the two tasks did not correlate, and participants requested significantly less information on the beads task relative to the box task. High-delusion-prone participants did not demonstrate hastier decisions on either task; in fact, for box task, this group was observed to be significantly more conservative than low-delusion-prone group. Neither task was incentivized; results need replication with a clinical sample. Participants, and particularly those identified as high-delusion-prone, displayed a more conservative style of responding on the novel box task, relative to the beads task. The two tasks, whilst conceptually similar, appear to be tapping different cognitive processes. The implications of these results are discussed in relation to the JTC bias and the theoretical mechanisms thought to underlie it. Copyright © 2016 Elsevier Ltd. All rights reserved.

Testing complex animal cognition: Concept learning, proactive interference, and list memory.

PubMed

Wright, Anthony A

2018-01-01

This article describes an approach for assessing and comparing complex cognition in rhesus monkeys and pigeons by training them in a sequence of synergistic tasks, each yielding a whole function for enhanced comparisons. These species were trained in similar same/different tasks with expanding training sets (8, 16, 32, 64, 128 … 1024 pictures) followed by novel-stimulus transfer eventually resulting in full abstract-concept learning. Concept-learning functions revealed better rhesus transfer throughout and full concept learning at the 128 set, versus pigeons at the 256 set. They were then tested in delayed same/different tasks for proactive interference by inserting occasional tests within trial-unique sessions where the test stimulus matched a previous sample stimulus (1, 2, 4, 8, 16 trials prior). Proactive-interference functions revealed time-based interference for pigeons (1, 10 s delays), but event-based interference for rhesus (no effect of 1, 10, 20 s delays). They were then tested in list-memory tasks by expanding the sample to four samples in trial-unique sessions (minimizing proactive interference). The four-item, list-memory functions revealed strong recency memory at short delays, gradually changing to strong primacy memory at long delays over 30 s for rhesus, and 10 s for pigeons. Other species comparisons and future directions are discussed. © 2018 Society for the Experimental Analysis of Behavior.

Spatial working memory in Wistar rats: brain sex differences in metabolic activity.

PubMed

Méndez-López, Magdalena; Méndez, Marta; López, Laudino; Arias, Jorge L

2009-05-29

Several works have shown that males and females differ in the ability to learn spatial locations in mazes. In this study, we used the Morris water maze to assess the acquisition of a spatial working memory (WM) task in adult male and female Wistar rats. The task consisted of a paired sample procedure made up of two daily identical trials, sample and retention. To study the oxidative metabolic activity of some brain limbic system regions after the WM task, we applied the cytochrome oxidase (COx) histochemistry. In addition to the experimental groups, free swimming control groups and untrained naïve groups were added to explore the COx changes not specific to the learning process. Similar spatial performances were found between sexes as only one more sample and retention trials were needed in males to reduce the escape latencies significantly. Males showed decreased COx activity as compared to control groups in the medial prefrontal cortex (prelimbic and infralimbic regions) as well as in the lateral septum and dentate gyrus. Regarding females, an increase in COx activity was found in nucleus accumbens, ventral tegmental area and supramammillary region in relation to control groups. Overall, these findings suggest that the acquisition of the spatial WM task is mediated by different subsystems in a sex-dependent manner that points to the hippocampus as the central structure in males whereas other structures would be central in females.

School Social Workers' Perceived Efficacy at Tasks Related to Curbing Suspension and Undesirable Behaviors

ERIC Educational Resources Information Center

Teasley, Martell L.; Miller, Christina R.

2011-01-01

This study explores school social workers' perceptions of their ability to successfully engage in practice tasks that reduce the likelihood of school suspension and undesirable behaviors among racial and ethnic groups within diverse geographical locations (urban, suburban, and rural). Using survey research methods with a convenience sample, 201…

PSSA Released Reading Items, 2000-2001. The Pennsylvania System of School Assessment.

ERIC Educational Resources Information Center

Pennsylvania State Dept. of Education, Harrisburg. Bureau of Curriculum and Academic Services.

This document contains materials directly related to the actual reading test of the Pennsylvania System of School Assessment (PSSA), including the reading rubric, released passages, selected-response questions with answer keys, performance tasks, and scored samples of students' responses to the tasks. All of these items may be duplicated to…

Salient and Emerging Developmental Tasks in the Transition to Adulthood

ERIC Educational Resources Information Center

Roisman, Glenn I.; Masten, Ann S.; Coatsworth, J. Douglas; Tellegen, Auke

2004-01-01

Drawing on data from a normative sample of 205 children tracked into adulthood, this study examined the predictive links from 3 salient (friendship, academic, conduct) and 2 emerging (work, romantic) developmental tasks during the transition years around age 20 to adult adaptation 10 years later. Results (a) confirm the utility of salient…

Children's Language Assessment--Situational Tasks.

ERIC Educational Resources Information Center

Conrad, Eva E.; And Others

The Children's Language Assessment-Situational Tasks (CLA-ST) was developed to collect language samples within a normally operating classroom. The language is taken on a cassette tape recorder, which is placed at the foot of a small table. At this table, in a committee setting, four children are engaged with a teacher in an activity similar to…

The Foster Care Project: Findings on Cognitive and Social-Emotional Development.

ERIC Educational Resources Information Center

McIntyre, Anne; Lounsbury, Karen Rasmussen

Findings of a study of a nonclinical sample of 30 kindergarten children and elementary school students in foster care suggest that few had mastered many of the fundamental psychosocial tasks of childhood. Primary measures were obtained by administering the Task of Emotional Development test (TED) -- a picture projective test designed to index…

SOCIOECONOMIC STATUS AND LEARNING PROFICIENCY IN YOUNG CHILDREN.

ERIC Educational Resources Information Center

ROHWER, WILLIAM D., JR.; AND OTHERS

THIS STUDY WAS INITIATED TO DETERMINE WHY CHILDREN OF LOWER SOCIOECONOMIC STATUS, WHO DO INFERIOR WORK ON SCHOOL-RELATED LEARNING TASKS WHEN COMPARED TO UPPER SOCIOECONOMIC STATUS CHILDREN, LEARN AS EFFICIENTLY AS UPPER LEVEL CHILDREN ON PAIRED-ASSOCIATE TASKS. THE SAMPLE CONSISTED OF 120 LOWER STATUS CHILDREN AND 120 UPPER STATUS CHILDREN,…

Performance-Based Task Assessment of Higher-Order Proficiencies in Redesigned STEM High Schools

ERIC Educational Resources Information Center

Ernst, Jeremy V.; Glennie, Elizabeth; Li, Songze

2017-01-01

This study explored student abilities in applying conceptual knowledge when presented with structured performance tasks. Specifically, the study gauged proficiency in higher-order applications of students enrolled in earth and environmental science or biology. The student sample was drawn from a Redesigned STEM high school model where a tested…

Basic Auditory Processing Skills and Phonological Awareness in Low-IQ Readers and Typically Developing Controls

ERIC Educational Resources Information Center

Kuppen, Sarah; Huss, Martina; Fosker, Tim; Fegan, Natasha; Goswami, Usha

2011-01-01

We explore the relationships between basic auditory processing, phonological awareness, vocabulary, and word reading in a sample of 95 children, 55 typically developing children, and 40 children with low IQ. All children received nonspeech auditory processing tasks, phonological processing and literacy measures, and a receptive vocabulary task.…

The Value of Emoticons in Investigating Student Emotions Related to Mathematics Task Negotiation

ERIC Educational Resources Information Center

D'Agostin, Fabio

2014-01-01

"Emoticons" are simple face icons expressing common feelings such as happiness, interest and boredom and are popularly used in electronic communication. Emoticons were utilised in this study as experience sampling devices. Year 10 students selected emoticons to indicate their emotional states at set intervals during classroom tasks.…

The Adaptation and Validation of the Emotion Matching Task for Preschool Children in Spain

ERIC Educational Resources Information Center

Alonso-Alberca, Natalia; Vergara, Ana I.; Fernandez-Berrocal, Pablo; Johnson, Stacy R.; Izard, Carroll E.

2012-01-01

The Emotion Matching Task (EMT; Izard, Haskins, Schultz, Trentacosta, & King, 2003) was developed to assess emotion knowledge in preschoolers and was demonstrated to show adequate convergent and predictive validity in an American sample (Morgan, Izard, & King, 2010). In light of the need for valid measures for assessing emotion…

Prerequisite Skills That Support Learning through Video Modeling

ERIC Educational Resources Information Center

MacDonald, Rebecca P. F.; Dickson, Chata A.; Martineau, Meaghan; Ahearn, William H.

2015-01-01

The purpose of this study was to evaluate the relationship between tasks that require delayed discriminations such as delayed imitation and delayed matching to sample on acquisition of skills using video modeling. Twenty-nine participants with an ASD diagnosis were assessed on a battery of tasks including both immediate and delayed imitation and…

Integration of Smart Board Technology and Effective Teaching

ERIC Educational Resources Information Center

Min, Kathryn; Siegel, Christine

2011-01-01

The proposed paper reports on the results of a study conducted to explore the influence of SMART Board technology on student engagement in and perception of classroom activities. Using momentary time-sampling procedures, this study examined differences in second grade students' on-task and off-task behaviors during 30-minute math and science…

Young Learners' Response Processes When Taking Computerized Tasks for Speaking Assessment

ERIC Educational Resources Information Center

Lee, Shinhye; Winke, Paula

2018-01-01

We investigated how young language learners process their responses on and perceive a computer-mediated, timed speaking test. Twenty 8-, 9-, and 10-year-old non-native English-speaking children (NNSs) and eight same-aged, native English-speaking children (NSs) completed seven computerized sample TOEFL® Primary™ speaking test tasks. We investigated…

The Contribution of the Left Mid-fusiform Cortical Thickness to Chinese and English Reading in a Large Chinese Sample

PubMed Central

Zhang, Mingxia; Li, Jin; Chen, Chuansheng; Mei, Leilei; Xue, Gui; Lu, Zhonglin; Chen, Chunhui; He, Qinghua; Wei, Miao; Dong, Qi

2012-01-01

Previous functional neuroimaging studies have shown that the left mid-fusiform cortex plays a critical role in reading. However, there is very limited research relating this region’s anatomical structure to reading performance either in native or second language. Using structural MRI and three reading tasks (Chinese characters, English words, and alphabetic pseudowords) and a non-reading task (visual-auditory learning), this study investigated the contributions of the left mid-fusiform cortical thickness to reading in a large sample of 226 Chinese subjects. Results showed that cortical thickness in the left mid-fusiform gyrus was positively correlated with performance on all three reading tasks but not with the performance on the non-reading task. Our findings provide structural evidence for the left mid-fusiform cortex as the “gateway” region for reading Chinese and English. The absence of the association between the left mid-fusiform cortical thickness and non-reading performance implied the specific role of this area in reading skills, not in general language skills. PMID:23022094

Media multitasking and behavioral measures of sustained attention.

PubMed

Ralph, Brandon C W; Thomson, David R; Seli, Paul; Carriere, Jonathan S A; Smilek, Daniel

2015-02-01

In a series of four studies, self-reported media multitasking (using the media multitasking index; MMI) and general sustained-attention ability, through performance on three sustained-attention tasks: the metronome response task (MRT), the sustained-attention-to-response task (SART), and a vigilance task (here, a modified version of the SART). In Study 1, we found that higher reports of media multitasking were associated with increased response variability (i.e., poor performance) on the MRT. However, in Study 2, no association between reported media multitasking and performance on the SART was observed. These findings were replicated in Studies 3a and 3b, in which we again assessed the relation between media multitasking and performance on both the MRT and SART in two large online samples. Finally, in Study 4, using a large online sample, we tested whether media multitasking was associated with performance on a vigilance task. Although standard vigilance decrements were observed in both sensitivity (A') and response times, media multitasking was not associated with the size of these decrements, nor was media multitasking associated with overall performance, in terms of either sensitivity or response times. Taken together, the results of the studies reported here failed to demonstrate a relation between habitual engagement in media multitasking in everyday life and a general deficit in sustained-attention processes.

Both hands at work: the effect of aging on upper-limb kinematics in a multi-step activity of daily living.

PubMed

Gulde, Philipp; Hermsdörfer, Joachim

2017-05-01

The kinematic performance of basic motor tasks shows a clear decrease with advancing age. This study examined if the rules known from such tasks can be generalized to activities of daily living. We examined the end-effector kinematics of 13 young and 13 elderly participants in the multi-step activity of daily living of tea-making. Furthermore, we analyzed bimanual behavior and hand dominance in the task using different conditions of execution. The elderly sample took substantially longer to complete the activity (almost 50%) with longer trajectories compared with the young sample. Models of multiple linear regression revealed that the longer trajectories prolonged the trial duration in both groups, and while movement speed influenced the trial duration of young participants, phases of inactivity negatively affected how long the activity took the elderly subjects. No differences were found regarding bimanual performance or hand dominance. We assume that in self-paced activities of daily living, the age-dependent differences in the kinematics are more likely to be based on the higher cognitive demands of the task rather than on pure motor capability. Furthermore, it seems that not all of the rules known from basic motor tasks can be generalized to activities of daily living.

Expecting innovation: psychoactive drug primes and the generation of creative solutions.

PubMed

Hicks, Joshua A; Pedersen, Sarah L; Pederson, Sarah L; Friedman, Ronald S; McCarthy, Denis M

2011-08-01

Many individuals expect that alcohol and drug consumption will enhance creativity. The present studies tested whether substance related primes would influence creative performance for individuals who possessed creativity-related substance expectancies. Participants (n = 566) were briefly exposed to stimuli related to psychoactive substances (alcohol, for Study 1, Sample 1, and Study 2; and marijuana, for Study 1, Sample 2) or neutral stimuli. Participants in Study 1 then completed a creative problem-solving task, while participants in Study 2 completed a divergent thinking task or a task unrelated to creative problem solving. The results of Study 1 revealed that exposure to the experimental stimuli enhanced performance on the creative problem-solving task for those who expected the corresponding substance would trigger creative functioning. In a conceptual replication, Study 2 showed that participants exposed to alcohol cues performed better on a divergent thinking task if they expected alcohol to enhance creativity. It is important to note that this same interaction did not influence performance on measures unrelated to creative problem solving, suggesting that the activation of creativity-related expectancies influenced creative performance, specifically. These findings highlight the importance of assessing expectancies when examining pharmacological effects of alcohol and marijuana. Future directions and implications for substance-related interventions are discussed. (c) 2011 APA, all rights reserved.

Results for the Fourth Quarter Calendar Year 2015 Tank 50H Salt Solution Sample

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

Crawford, C.

In this memorandum, the chemical and radionuclide contaminant results from the Fourth Quarter Calendar Year 2015 (CY15) sample of Tank 50H salt solution are presented in tabulated form. The Fourth Quarter CY15 Tank 50H samples were obtained on October 29, 2015 and received at Savannah River National Laboratory (SRNL) on October 30, 2015. The information from this characterization will be used by Defense Waste Processing Facility (DWPF) & Saltstone Facility Engineering for the transfer of aqueous waste from Tank 50H to the Salt Feed Tank in the Saltstone Production Facility, where the waste will be treated and disposed of inmore » the Saltstone Disposal Facility. This memorandum compares results, where applicable, to Saltstone Waste Acceptance Criteria (WAC) limits and targets. Data pertaining to the regulatory limits for Resource Conservation and Recovery Act (RCRA) metals will be documented at a later time per the Task Technical and Quality Assurance Plan (TTQAP) for the Tank 50H saltstone task. The chemical and radionuclide contaminant results from the characterization of the Fourth Quarter Calendar Year 2015 (CY15) sampling of Tank 50H were requested by SRR personnel and details of the testing are presented in the SRNL Task Technical and Quality Assurance Plan.« less

A sequential sampling account of response bias and speed-accuracy tradeoffs in a conflict detection task.

PubMed

Vuckovic, Anita; Kwantes, Peter J; Humphreys, Michael; Neal, Andrew

2014-03-01

Signal Detection Theory (SDT; Green & Swets, 1966) is a popular tool for understanding decision making. However, it does not account for the time taken to make a decision, nor why response bias might change over time. Sequential sampling models provide a way of accounting for speed-accuracy trade-offs and response bias shifts. In this study, we test the validity of a sequential sampling model of conflict detection in a simulated air traffic control task by assessing whether two of its key parameters respond to experimental manipulations in a theoretically consistent way. Through experimental instructions, we manipulated participants' response bias and the relative speed or accuracy of their responses. The sequential sampling model was able to replicate the trends in the conflict responses as well as response time across all conditions. Consistent with our predictions, manipulating response bias was associated primarily with changes in the model's Criterion parameter, whereas manipulating speed-accuracy instructions was associated with changes in the Threshold parameter. The success of the model in replicating the human data suggests we can use the parameters of the model to gain an insight into the underlying response bias and speed-accuracy preferences common to dynamic decision-making tasks. © 2013 American Psychological Association

A Phase 2 Trial on the Effect of Low-Dose versus High-Dose Vitamin D Supplementation on Bone Mass in Adults with Neurofibromatosis 1 (NF1)

DTIC Science & Technology

2014-10-01

number/communicate to site coordinator N/A Task V.5 (mo 6-47): implement methods to educate/monitor participants on aspects of vit D3 and calcium...potential side effects of vit D3 supplementation CRFs for adverse event reporting have been developed and included in the protocols submitted for IRB...Task VI.3 (mo 6-47): document acceptance of storage sample in the CGRP database and vit D3 study database The process for storage of sample in the

Sensory factors affecting female consumers' acceptability of nail polish.

PubMed

Sun, C; Koppel, K; Adhikari, K

2015-12-01

The objectives of this study were to determine what sensory factors impact consumers' acceptability of nail polishes, to explore how these sensory factors impact consumers' acceptability of nail polishes, to investigate whether there are any consumer segments according to their overall acceptability on different nail polishes and to scrutinize how the consumer segments are related to the sensory factors. Ninety-eight females participated in a nail polish consumer study at Kansas State University. Eight commercial products belonging to four categories - regular (REG), gel (GEL), flake (FLK) and water-based (WAT) - were evaluated. Each nail polish sample was evaluated twice by each participant in two different tasks - a task devoted to applying and evaluating the product and a task devoted to observing the appearance and evaluating the product. Pearson's correlation analysis, analysis of variance (ANOVA), external preference mapping, cluster analysis and internal preference mapping were applied for data analysis. Participants' scores of overall liking of the nail polishes were similar in the application task and in the observation task. In general, participants liked the REG and GEL product samples more than the FLK and WAT samples. Among all the sensory attributes, appearance attributes were the major factors that affected participants' overall liking. Aroma seemed to be a minor factor to participants' overall liking. Some sensory attributes, such as runny, shininess, opacity, spreadability, smoothness, coverage and wet appearance, were found to drive participants' overall acceptability positively, whereas others such as pinhole, fatty-edges, blister, brushlines, pearl-like, flake-protrusion, glittery and initial-drag impacted participants' overall acceptability negatively. Four clusters of participants were identified according to their overall liking scores from both the application task and the observation task. Participants' acceptability, based on different sensory attributes, could help a nail polish manufacturer modify or improve their nail polish formulas. Nail polish manufacturers could use the consumer cluster information to improve their marketing strategies for specific categories of their products and to target their advertising on particular consumer groups. © 2015 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

The Curvilinear Relationship between State Neuroticism and Momentary Task Performance

PubMed Central

Debusscher, Jonas; Hofmans, Joeri; De Fruyt, Filip

2014-01-01

A daily diary and two experience sampling studies were carried out to investigate curvilinearity of the within-person relationship between state neuroticism and task performance, as well as the moderating effects of within-person variation in momentary job demands (i.e., work pressure and task complexity). In one, results showed that under high work pressure, the state neuroticism–task performance relationship was best described by an exponentially decreasing curve, whereas an inverted U-shaped curve was found for tasks low in work pressure, while in another study, a similar trend was visible for task complexity. In the final study, the state neuroticism–momentary task performance relationship was a linear one, and this relationship was moderated by momentary task complexity. Together, results from all three studies showed that it is important to take into account the moderating effects of momentary job demands because within-person variation in job demands affects the way in which state neuroticism relates to momentary levels of task performance. Specifically, we found that experiencing low levels of state neuroticism may be most beneficial in high demanding tasks, whereas more moderate levels of state neuroticism are optimal under low momentary job demands. PMID:25238547

Improving Efficiency with Work Sampling.

ERIC Educational Resources Information Center

Friedman, Mark; Hertz, Paul

1982-01-01

Work sampling is a managerial accounting technique which provides information about the efficiency of an operation. This analysis determines what tasks are being performed durinq a period of time to ascertain if time and effort are being allocated efficiently. (SK)

Analogical reasoning in amazons.

PubMed

Obozova, Tanya; Smirnova, Anna; Zorina, Zoya; Wasserman, Edward

2015-11-01

Two juvenile orange-winged amazons (Amazona amazonica) were initially trained to match visual stimuli by color, shape, and number of items, but not by size. After learning these three identity matching-to-sample tasks, the parrots transferred discriminative responding to new stimuli from the same categories that had been used in training (other colors, shapes, and numbers of items) as well as to stimuli from a different category (stimuli varying in size). In the critical testing phase, both parrots exhibited reliable relational matching-to-sample (RMTS) behavior, suggesting that they perceived and compared the relationship between objects in the sample stimulus pair to the relationship between objects in the comparison stimulus pairs, even though no physical matches were possible between items in the sample and comparison pairs. The parrots spontaneously exhibited this higher-order relational responding without having ever before been trained on RMTS tasks, therefore joining apes and crows in displaying this abstract cognitive behavior.

Experimental scattershot boson sampling

PubMed Central

Bentivegna, Marco; Spagnolo, Nicolò; Vitelli, Chiara; Flamini, Fulvio; Viggianiello, Niko; Latmiral, Ludovico; Mataloni, Paolo; Brod, Daniel J.; Galvão, Ernesto F.; Crespi, Andrea; Ramponi, Roberta; Osellame, Roberto; Sciarrino, Fabio

2015-01-01

Boson sampling is a computational task strongly believed to be hard for classical computers, but efficiently solvable by orchestrated bosonic interference in a specialized quantum computer. Current experimental schemes, however, are still insufficient for a convincing demonstration of the advantage of quantum over classical computation. A new variation of this task, scattershot boson sampling, leads to an exponential increase in speed of the quantum device, using a larger number of photon sources based on parametric down-conversion. This is achieved by having multiple heralded single photons being sent, shot by shot, into different random input ports of the interferometer. We report the first scattershot boson sampling experiments, where six different photon-pair sources are coupled to integrated photonic circuits. We use recently proposed statistical tools to analyze our experimental data, providing strong evidence that our photonic quantum simulator works as expected. This approach represents an important leap toward a convincing experimental demonstration of the quantum computational supremacy. PMID:26601164

Experimental scattershot boson sampling.

PubMed

Bentivegna, Marco; Spagnolo, Nicolò; Vitelli, Chiara; Flamini, Fulvio; Viggianiello, Niko; Latmiral, Ludovico; Mataloni, Paolo; Brod, Daniel J; Galvão, Ernesto F; Crespi, Andrea; Ramponi, Roberta; Osellame, Roberto; Sciarrino, Fabio

2015-04-01

Boson sampling is a computational task strongly believed to be hard for classical computers, but efficiently solvable by orchestrated bosonic interference in a specialized quantum computer. Current experimental schemes, however, are still insufficient for a convincing demonstration of the advantage of quantum over classical computation. A new variation of this task, scattershot boson sampling, leads to an exponential increase in speed of the quantum device, using a larger number of photon sources based on parametric down-conversion. This is achieved by having multiple heralded single photons being sent, shot by shot, into different random input ports of the interferometer. We report the first scattershot boson sampling experiments, where six different photon-pair sources are coupled to integrated photonic circuits. We use recently proposed statistical tools to analyze our experimental data, providing strong evidence that our photonic quantum simulator works as expected. This approach represents an important leap toward a convincing experimental demonstration of the quantum computational supremacy.

Sample size in psychological research over the past 30 years.

PubMed

Marszalek, Jacob M; Barber, Carolyn; Kohlhart, Julie; Holmes, Cooper B

2011-04-01

The American Psychological Association (APA) Task Force on Statistical Inference was formed in 1996 in response to a growing body of research demonstrating methodological issues that threatened the credibility of psychological research, and made recommendations to address them. One issue was the small, even dramatically inadequate, size of samples used in studies published by leading journals. The present study assessed the progress made since the Task Force's final report in 1999. Sample sizes reported in four leading APA journals in 1955, 1977, 1995, and 2006 were compared using nonparametric statistics, while data from the last two waves were fit to a hierarchical generalized linear growth model for more in-depth analysis. Overall, results indicate that the recommendations for increasing sample sizes have not been integrated in core psychological research, although results slightly vary by field. This and other implications are discussed in the context of current methodological critique and practice.

Parents' self-efficacy, outcome expectations, and self-reported task performance when managing atopic dermatitis in children: instrument reliability and validity.

PubMed

Mitchell, Amy E; Fraser, Jennifer A

2011-02-01

Support and education for parents faced with managing a child with atopic dermatitis is crucial to the success of current treatments. Interventions aiming to improve parent management of this condition are promising. Unfortunately, evaluation is hampered by lack of precise research tools to measure change. To develop a suite of valid and reliable research instruments to appraise parents' self-efficacy for performing atopic dermatitis management tasks; outcome expectations of performing management tasks; and self-reported task performance in a community sample of parents of children with atopic dermatitis. The Parents' Eczema Management Scale (PEMS) and the Parents' Outcome Expectations of Eczema Management Scale (POEEMS) were developed from an existing self-efficacy scale, the Parental Self-Efficacy with Eczema Care Index (PASECI). Each scale was presented in a single self-administered questionnaire, to measure self-efficacy, outcome expectations, and self-reported task performance related to managing child atopic dermatitis. Each was tested with a community sample of parents of children with atopic dermatitis, and psychometric evaluation of the scales' reliability and validity was conducted. A community-based convenience sample of 120 parents of children with atopic dermatitis completed the self-administered questionnaire. Participants were recruited through schools across Australia. Satisfactory internal consistency and test-retest reliability was demonstrated for all three scales. Construct validity was satisfactory, with positive relationships between self-efficacy for managing atopic dermatitis and general perceived self-efficacy; self-efficacy for managing atopic dermatitis and self-reported task performance; and self-efficacy for managing atopic dermatitis and outcome expectations. Factor analyses revealed two-factor structures for PEMS and PASECI alike, with both scales containing factors related to performing routine management tasks, and managing the child's symptoms and behaviour. Factor analysis was also applied to POEEMS resulting in a three-factor structure. Factors relating to independent management of atopic dermatitis by the parent, involving healthcare professionals in management, and involving the child in the management of atopic dermatitis were found. Parents' self-efficacy and outcome expectations had a significant influence on self-reported task performance. Findings suggest that PEMS and POEEMS are valid and reliable instruments worthy of further psychometric evaluation. Likewise, validity and reliability of PASECI was confirmed. Copyright © 2010 Elsevier Ltd. All rights reserved.

Silica exposure during construction activities: statistical modeling of task-based measurements from the literature.

PubMed

Sauvé, Jean-François; Beaudry, Charles; Bégin, Denis; Dion, Chantal; Gérin, Michel; Lavoué, Jérôme

2013-05-01

Many construction activities can put workers at risk of breathing silica containing dusts, and there is an important body of literature documenting exposure levels using a task-based strategy. In this study, statistical modeling was used to analyze a data set containing 1466 task-based, personal respirable crystalline silica (RCS) measurements gathered from 46 sources to estimate exposure levels during construction tasks and the effects of determinants of exposure. Monte-Carlo simulation was used to recreate individual exposures from summary parameters, and the statistical modeling involved multimodel inference with Tobit models containing combinations of the following exposure variables: sampling year, sampling duration, construction sector, project type, workspace, ventilation, and controls. Exposure levels by task were predicted based on the median reported duration by activity, the year 1998, absence of source control methods, and an equal distribution of the other determinants of exposure. The model containing all the variables explained 60% of the variability and was identified as the best approximating model. Of the 27 tasks contained in the data set, abrasive blasting, masonry chipping, scabbling concrete, tuck pointing, and tunnel boring had estimated geometric means above 0.1mg m(-3) based on the exposure scenario developed. Water-fed tools and local exhaust ventilation were associated with a reduction of 71 and 69% in exposure levels compared with no controls, respectively. The predictive model developed can be used to estimate RCS concentrations for many construction activities in a wide range of circumstances.

Auditory working memory impairments in individuals at familial high risk for schizophrenia.

PubMed

Seidman, Larry J; Meyer, Eric C; Giuliano, Anthony J; Breiter, Hans C; Goldstein, Jill M; Kremen, William S; Thermenos, Heidi W; Toomey, Rosemary; Stone, William S; Tsuang, Ming T; Faraone, Stephen V

2012-05-01

The search for predictors of schizophrenia has accelerated with a growing focus on early intervention and prevention of psychotic illness. Studying nonpsychotic relatives of individuals with schizophrenia enables identification of markers of vulnerability for the illness independent of confounds associated with psychosis. The goal of these studies was to develop new auditory continuous performance tests (ACPTs) and evaluate their effects in individuals with schizophrenia and their relatives. We carried out two studies of auditory vigilance with tasks involving working memory (WM) and interference control with increasing levels of cognitive load to discern the information-processing vulnerabilities in a sample of schizophrenia patients, and two samples of nonpsychotic relatives of individuals with schizophrenia and controls. Study 1 assessed adults (mean age = 41), and Study 2 assessed teenagers and young adults age 13-25 (M = 19). Patients with schizophrenia were impaired on all five versions of the ACPTs, whereas relatives were impaired only on WM tasks, particularly the two interference tasks that maximize cognitive load. Across all groups, the interference tasks were more difficult to perform than the other tasks. Schizophrenia patients performed worse than relatives, who performed worse than controls. For patients, the effect sizes were large (Cohen's d = 1.5), whereas for relatives they were moderate (d = ~0.40-0.50). There was no age by group interaction in the relatives-control comparison except for participants <31 years of age. Novel WM tasks that manipulate cognitive load and interference control index an important component of the vulnerability to schizophrenia.

Children’s mental time travel during mind wandering

PubMed Central

Ye, Qun; Song, Xiaolan; Zhang, Yi; Wang, Qinqin

2014-01-01

The prospective bias is a salient feature of mind wandering in healthy adults, yet little is known about the temporal focus of children’s mind wandering. In the present study, (I) we developed the temporal focus of mind wandering questionnaire for school-age children (TFMWQ-C), a 12-item scale with good test–retest reliability and construct validity. (II) The criterion validity was tested by thought sampling in both choice reaction time task and working memory task. A positive correlation was found between the temporal focus measured by the questionnaire and the one adopted during task-unrelated thoughts (TUTs) by thought sampling probes, especially in the trait level of future-oriented mind wandering. At the same time, children who experienced more TUTs tended to show worse behavioral performance during tasks. (III) The children in both tasks experienced more future-oriented TUTs than past-oriented ones, which was congruent with the results observed in adults; however, in contrast with previous research on adults, the prospective bias was not influenced by task demands. Together these results indicate that the prospective bias of mind wandering has emerged since the school-age (9∼13 years old), and that the relationship between mental time travel (MTT) during mind wandering and the use of cognitive resources differs between children and adults. Our study provides new insights into how this interesting feature of mind wandering may adaptively contribute to the development of children’s MTT. PMID:25191301

Test battery for measuring the perception and recognition of facial expressions of emotion

PubMed Central

Wilhelm, Oliver; Hildebrandt, Andrea; Manske, Karsten; Schacht, Annekathrin; Sommer, Werner

2014-01-01

Despite the importance of perceiving and recognizing facial expressions in everyday life, there is no comprehensive test battery for the multivariate assessment of these abilities. As a first step toward such a compilation, we present 16 tasks that measure the perception and recognition of facial emotion expressions, and data illustrating each task's difficulty and reliability. The scoring of these tasks focuses on either the speed or accuracy of performance. A sample of 269 healthy young adults completed all tasks. In general, accuracy and reaction time measures for emotion-general scores showed acceptable and high estimates of internal consistency and factor reliability. Emotion-specific scores yielded lower reliabilities, yet high enough to encourage further studies with such measures. Analyses of task difficulty revealed that all tasks are suitable for measuring emotion perception and emotion recognition related abilities in normal populations. PMID:24860528

Nonparametric EROC analysis for observer performance evaluation on joint detection and estimation tasks

NASA Astrophysics Data System (ADS)

Wunderlich, Adam; Goossens, Bart

2014-03-01

The majority of the literature on task-based image quality assessment has focused on lesion detection tasks, using the receiver operating characteristic (ROC) curve, or related variants, to measure performance. However, since many clinical image evaluation tasks involve both detection and estimation (e.g., estimation of kidney stone composition, estimation of tumor size), there is a growing interest in performance evaluation for joint detection and estimation tasks. To evaluate observer performance on such tasks, Clarkson introduced the estimation ROC (EROC) curve, and the area under the EROC curve as a summary figure of merit. In the present work, we propose nonparametric estimators for practical EROC analysis from experimental data, including estimators for the area under the EROC curve and its variance. The estimators are illustrated with a practical example comparing MRI images reconstructed from different k-space sampling trajectories.

Task-focused behavior mediates the associations between supportive interpersonal environments and students' academic performance.

PubMed

Kiuru, Noona; Pakarinen, Eija; Vasalampi, Kati; Silinskas, Gintautas; Aunola, Kaisa; Poikkeus, Anna-Maija; Metsäpelto, Riitta-Leena; Lerkkanen, Marja-Kristiina; Nurmi, Jari-Erik

2014-04-01

In the longitudinal study presented here, we tested the theoretical assumption that children's task-focused behavior in learning situations mediates the associations between supportive interpersonal environments and academic performance. The sample consisted of 2,137 Finnish-speaking children. Data on supportive interpersonal environments (characterized by authoritative parenting, positive teacher affect toward the child, and peer acceptance) were gathered in Grade 1. The children's task-focused behavior was measured in Grades 2 and 3, and academic performance was measured in Grades 1 and 4. The results supported our assumption by showing that all three supportive environments were positively associated with children's subsequent academic performance via increased task-focused behavior in learning situations. These findings suggest that students' academic performance can be promoted by increasing the support they receive from peers, parents, and teachers because such increased support leads to better task focus in learning tasks.

HLLV avionics requirements study and electronic filing system database development

NASA Technical Reports Server (NTRS)

1994-01-01

This final report provides a summary of achievements and activities performed under Contract NAS8-39215. The contract's objective was to explore a new way of delivering, storing, accessing, and archiving study products and information and to define top level system requirements for Heavy Lift Launch Vehicle (HLLV) avionics that incorporate Vehicle Health Management (VHM). This report includes technical objectives, methods, assumptions, recommendations, sample data, and issues as specified by DPD No. 772, DR-3. The report is organized into two major subsections, one specific to each of the two tasks defined in the Statement of Work: the Index Database Task and the HLLV Avionics Requirements Task. The Index Database Task resulted in the selection and modification of a commercial database software tool to contain the data developed during the HLLV Avionics Requirements Task. All summary information is addressed within each task's section.

A developmental neuroimaging investigation of the change paradigm.

PubMed

Thomas, Laura A; Hall, Julie M; Skup, Martha; Jenkins, Sarah E; Pine, Daniel S; Leibenluft, Ellen

2011-01-01

This neuroimaging study examines the development of cognitive flexibility using the Change task in a sample of youths and adults. The Change task requires subjects to inhibit a prepotent response and substitute an alternative response, and the task incorporates an algorithm that adjusts task difficulty in response to subject performance. Data from both groups combined show a network of prefrontal and parietal areas that are active during the task. For adults vs. youths, a distributed network was more active for successful change trials versus go, baseline, or unsuccessful change trials. This network included areas involved in rule representation, retrieval (lateral PFC), and switching (medial PFC and parietal regions). These results are consistent with data from previous task-switching experiments and inform developmental understandings of cognitive flexibility. Published 2010. This article is a US Government work and is in the public domain in the USA.

Adaptive Oceanographic Sampling in a Coastal Environment Using Autonomous Gliding Vehicles

DTIC Science & Technology

2003-08-01

cost autonomous vehicles with near-global range and modular sensor payload. Particular emphasis is placed on the development of adaptive sampling...environment. Secondary objectives include continued development of adaptive sampling strategies suitable for large fleets of slow-moving autonomous ... vehicles , and development and implementation of new oceanographic sensors and sampling methodologies. The main task completed was a complete redesign of

Parameter Estimation with Small Sample Size: A Higher-Order IRT Model Approach

ERIC Educational Resources Information Center

de la Torre, Jimmy; Hong, Yuan

2010-01-01

Sample size ranks as one of the most important factors that affect the item calibration task. However, due to practical concerns (e.g., item exposure) items are typically calibrated with much smaller samples than what is desired. To address the need for a more flexible framework that can be used in small sample item calibration, this article…

Definitions of homework, types of homework, and ratings of the importance of homework among psychologists with cognitive behavior therapy and psychoanalytic theoretical orientations.

PubMed

Kazantzis, Nikolaos; Dattilio, Frank M

2010-07-01

A random sample of 827 psychologists were surveyed to assess their definitions of homework, use of homework tasks, and perceived importance of homework. Theoretical orientation distinguished practitioners' responses. Cognitive-behavioral therapists defined homework as being closer to empirically supported therapy, whereas psychodynamic therapists rated homework as less characteristic of a process that embraces client responsibility and adaptive skills. Cognitive-behavior therapists did not limit their choices to activity-based tasks, and psychodynamic therapists reported using behavioral tasks "sometimes." Monitoring dreams and conscious thought were also used among the entire sample surveyed. Psychodynamic therapists rated homework as "somewhat" or "moderately" important, whereas cognitive-behavior therapists more often rated homework as "very important." Data suggest some homework may be common to different psychotherapeutic approaches. Findings are discussed in the context of recent theoretical work on homework in psychotherapy and recommendations for future research.

Delayed match-to-sample early performance decrement in monkeys after $sup 60$Co irradiation

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

Bruner, A.; Bogo, V.; Jones, R.K.

1975-07-01

Sixteen monkeys were trained on a delayed match-to-sample task (DMTS) based on shock avoidance and irradiated with single, whole-body exposures of from 396 to 2000 rad $sup 60$Co (midbody dose) at between 163 and 233 rad/min. Pre- to post-irradiation performance changes were assessed using a penalty-scaling measure which differentially weighted incorrect responses, response omissions, and error-omission sequences. Thirteen of the animals displayed early performance decrement, including five incapacitations, at lower doses (less than 1000 rad) than heretofore found effective. This was considered a function of task complexity, measurement sensitivity, and gamma effectiveness. The minimum effective midbody dose for inducing decrementmore » using the DMTS task was estimated to be on the order of 500 rad. The nature of early, transient performance decrement seems to reflect more of an inability to perform than an inability to perform correctly. (auth)« less

Results of Hg speciation testing on MCU strip effluent hold tank (SEHT) and decontaminated salt solution hold tank (DSSHT) materials

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

Bannochie, C. J.

2015-09-17

The Savannah River National Laboratory (SRNL) was tasked with preparing and shipping samples for Hg speciation by Eurofins Frontier Global Sciences, Inc. in Seattle, WA on behalf of the Savannah River Remediation (SRR) Mercury Task Team.i,ii The tenth shipment of samples was designated to include Modular Caustic Side Solvent Extraction Unit (MCU) Strip Effluent Hold Tank (SEHT) and MCU Decontaminated Salt Solution Hold Tank (DSSHT) materials from processing Salt Batch 7b. The MCU SEHT (MCU-15-722) and DSSHT (MCU-15-709) samples were pulled on June 15, 2015. All MCU samples were received at SRNL on June 16, 2015. The DSSHT sample wasmore » moved the same day to refrigeration, while the SEHT sample was placed in the Shielded Cells. On July 9, 2015 it was opened and an aliquot diluted 1:100 with Eurofins deionized water and a portion of the diluted sample transferred to a Teflon® bottle prior to moving it to refrigeration that same day. All samples were kept in the dark and refrigerated until final dilutions were prepared for shipment to Eurofins.« less

Cortisol Responses to a Group Public Speaking Task for Adolescents: Variations by Age, Gender, and Race

PubMed Central

Hostinar, Camelia E.; McQuillan, Mollie T.; Mirous, Heather J.; Grant, Kathryn E.; Adam, Emma K.

2014-01-01

Laboratory social stress tests involving public speaking challenges are widely used for eliciting an acute stress response in older children, adolescents, and adults. Recently, a group protocol for a social stress test (the Trier Social Stress Test for Groups, TSST-G) was shown to be effective in adults and is dramatically less time-consuming and resource-intensive compared to the single-subject version of the task. The present study sought to test the feasibility and effectiveness of an adapted group public speaking task conducted with a racially diverse, urban sample of U.S. adolescents (N = 191; 52.4% female) between the ages of 11 and 18 (M = 14.4 years, SD = 1.93). Analyses revealed that this Group Public Speaking Task for Adolescents (GPST-A) provoked a significant increase in cortisol production (on average, approximately 60% above baseline) and in self-reported negative affect, while at the same time avoiding excessive stress responses that would raise ethical concerns or provoke substantial participant attrition. Approximately 63.4% of participants exhibited an increase in cortisol levels in response to the task, with 59.2% of the total sample showing a 10% or greater increase from baseline. Results also suggested that groups of 5 adolescents might be ideal for achieving more uniform cortisol responses across various serial positions for speech delivery. Basal cortisol levels increased with age and participants belonging to U.S. national minorities tended to have either lower basal cortisol or diminished cortisol reactivity compared to non-Hispanic Whites. This protocol facilitates the recruitment of larger sample sizes compared to prior research and may show great utility in answering new questions about adolescent stress reactivity and development. PMID:25218656

Global/local processing of hierarchical visual stimuli in a conflict-choice task by capuchin monkeys (Sapajus spp.).

PubMed

Truppa, Valentina; Carducci, Paola; De Simone, Diego Antonio; Bisazza, Angelo; De Lillo, Carlo

2017-03-01

In the last two decades, comparative research has addressed the issue of how the global and local levels of structure of visual stimuli are processed by different species, using Navon-type hierarchical figures, i.e. smaller local elements that form larger global configurations. Determining whether or not the variety of procedures adopted to test different species with hierarchical figures are equivalent is of crucial importance to ensure comparability of results. Among non-human species, global/local processing has been extensively studied in tufted capuchin monkeys using matching-to-sample tasks with hierarchical patterns. Local dominance has emerged consistently in these New World primates. In the present study, we assessed capuchins' processing of hierarchical stimuli with a method frequently adopted in studies of global/local processing in non-primate species: the conflict-choice task. Different from the matching-to-sample procedure, this task involved processing local and global information retained in long-term memory. Capuchins were trained to discriminate between consistent hierarchical stimuli (similar global and local shape) and then tested with inconsistent hierarchical stimuli (different global and local shapes). We found that capuchins preferred the hierarchical stimuli featuring the correct local elements rather than those with the correct global configuration. This finding confirms that capuchins' local dominance, typically observed using matching-to-sample procedures, is also expressed as a local preference in the conflict-choice task. Our study adds to the growing body of comparative studies on visual grouping functions by demonstrating that the methods most frequently used in the literature on global/local processing produce analogous results irrespective of extent of the involvement of memory processes.

Cortisol responses to a group public speaking task for adolescents: variations by age, gender, and race.

PubMed

Hostinar, Camelia E; McQuillan, Mollie T; Mirous, Heather J; Grant, Kathryn E; Adam, Emma K

2014-12-01

Laboratory social stress tests involving public speaking challenges are widely used for eliciting an acute stress response in older children, adolescents, and adults. Recently, a group protocol for a social stress test (the Trier Social Stress Test for Groups, TSST-G) was shown to be effective in adults and is dramatically less time-consuming and resource-intensive compared to the single-subject version of the task. The present study sought to test the feasibility and effectiveness of an adapted group public speaking task conducted with a racially diverse, urban sample of U.S. adolescents (N=191; 52.4% female) between the ages of 11 and 18 (M=14.4 years, SD=1.93). Analyses revealed that this Group Public Speaking Task for Adolescents (GPST-A) provoked a significant increase in cortisol production (on average, approximately 60% above baseline) and in self-reported negative affect, while at the same time avoiding excessive stress responses that would raise ethical concerns or provoke substantial participant attrition. Approximately 63.4% of participants exhibited an increase in cortisol levels in response to the task, with 59.2% of the total sample showing a 10% or greater increase from baseline. Results also suggested that groups of five adolescents might be ideal for achieving more uniform cortisol responses across various serial positions for speech delivery. Basal cortisol levels increased with age and participants belonging to U.S. national minorities tended to have either lower basal cortisol or diminished cortisol reactivity compared to non-Hispanic Whites. This protocol facilitates the recruitment of larger sample sizes compared to prior research and may show great utility in answering new questions about adolescent stress reactivity and development. Copyright © 2014 Elsevier Ltd. All rights reserved.

Validation of a Behavioral Approach for Measuring Saccades in Parkinson's Disease.

PubMed

Turner, Travis H; Renfroe, Jenna B; Duppstadt-Delambo, Amy; Hinson, Vanessa K

2017-01-01

Speed and control of saccades are related to disease progression and cognitive functioning in Parkinson's disease (PD). Traditional eye-tracking complexities encumber application for individual evaluations and clinical trials. The authors examined psychometric properties of standalone tasks for reflexive prosaccade latency, volitional saccade initiation, and saccade inhibition (antisaccade) in a heterogeneous sample of 65 PD patients. Demographics had minimal impact on task performance. Thirty-day test-retest reliability estimates for behavioral tasks were acceptable and similar to traditional eye tracking. Behavioral tasks demonstrated concurrent validity with traditional eye-tracking measures; discriminant validity was less clear. Saccade initiation and inhibition discriminated PD patients with cognitive impairment. The present findings support further development and use of the behavioral tasks for assessing latency and control of saccades in PD.

Doing many things at a time: Lack of power decreases the ability to multitask.

PubMed

Cai, Ran Alice; Guinote, Ana

2017-09-01

Three studies investigated the effects of power on the ability to pursue multiple, concomitant goals, also known as multitasking. It was predicted that powerless participants will show lower multitasking ability than control and powerful participants. Study 1 focused on self-reported ability to multitask in a sample of executives and subordinate employees. Studies 2 and 3 investigated the ability to dual-task and to switch between tasks, respectively, using dual-task and task-switching paradigms. Across the studies, powerless individuals were less able to effectively multitask compared with control and powerful participants, suggesting that the detrimental effects of lack of power extend beyond single-task environments, shown in past research, into multitasking environments. Underlying mechanisms are discussed. © 2017 The British Psychological Society.

Associations between respiratory sinus arrhythmia (RSA) reactivity and effortful control in preschool-age children.

PubMed

Sulik, Michael J; Eisenberg, Nancy; Spinrad, Tracy L; Silva, Kassondra M

2015-07-01

We tested whether respiratory sinus arrhythmia (RSA) reactivity in response to each of three self-regulation tasks (bird and dragon; knock-tap; and gift wrap) would predict self-regulation performance in a sample of 101 preschool-age children (M age = 4.49, SD = .64). While controlling for baseline RSA, decreases in RSA from bird and dragon to knock-tap (but not from baseline to bird and dragon) predicted a latent variable measuring self-regulation. Furthermore, increases in RSA from the knock-tap to gift wrap-the only task involving delay of gratification-were related to concurrent task performance while controlling for the relation between RSA reactivity and the latent self-regulation variable. Results suggest that the relations between RSA reactivity and self-regulatory ability are influenced by task-specific demands and possibly by task order. Furthermore, RSA reactivity appears to relate differently to performance on motivationally salient self-regulation tasks such as delay of gratification relative to cool executive function tasks. © 2015 Wiley Periodicals, Inc.

Liquid hydrogen turbopump rapid start program. [thermal preconditioning using coatings

NASA Technical Reports Server (NTRS)

Wong, G. S.

1973-01-01

This program was to analyze, test, and evaluate methods of achieving rapid-start of a liquid hydrogen feed system (inlet duct and turbopump) using a minimum of thermal preconditioning time and propellant. The program was divided into four tasks. Task 1 includes analytical studies of the testing conducted in the other three tasks. Task 2 describes the results from laboratory testing of coating samples and the successful adherence of a KX-635 coating to the internal surfaces of the feed system tested in Task 4. Task 3 presents results of testing an uncoated feed system. Tank pressure was varied to determine the effect of flowrate on preconditioning. The discharge volume and the discharge pressure which initiates opening of the discharge valve were varied to determine the effect on deadhead (no through-flow) start transients. Task 4 describes results of testing a similar, internally coated feed system and illustrates the savings in preconditioning time and propellant resulting from the coatings.

Critical thinking about fables: examining language production and comprehension in adolescents.

PubMed

Nippold, Marilyn A; Frantz-Kaspar, Megan W; Cramond, Paige M; Kirk, Cecilia; Hayward-Mayhew, Christine; MacKinnon, Melanie

2015-04-01

This study was designed primarily to determine if a critical-thinking task involving fables would elicit greater syntactic complexity than a conversational task in adolescents. Another purpose was to determine how well adolescents understand critical-thinking questions about fables. Forty adolescents (N=20 boys and 20 girls; mean age=14 years) with typical language development answered critical-thinking questions about the deeper meanings of fables. They also participated in a standard conversational task. The syntactic complexity of their responses during the speaking tasks was analyzed for mean length of communication unit (MLCU) and clausal density (CD). Both measures of syntactic complexity, MLCU and CD, were substantially greater during the critical-thinking task compared with the conversational task. It was also found that the adolescents understood the questions quite well, earning a mean accuracy score of 80%. The critical-thinking task has potential for use as a new type of language-sampling tool to examine language production and comprehension in adolescents.

Cognitive Correlates of Perseverations in Individuals with Memory Impairment.

PubMed

Kavé, Gitit; Heinik, Jeremia

2017-02-01

This study examines which cognitive measure best accounts for perseverations in individuals with memory impairment. The sample included 85 individuals, of whom 21 had subjective memory concerns, 27 had mild cognitive impairment, and 37 had Alzheimer's disease. Participants produced responses on a semantic category fluency task and on the ideational fluency (IF) task from the Cambridge Cognitive Examination-Revised. Measures of word finding, working memory, and abstract thinking were also assessed. Significant group differences in percentage of perseverations emerged on both tasks. No cognitive measure accounted for the percentage of perseverations on the semantic fluency task. A measure of abstract thinking was the best predictor of the percentage of perseverations on the IF task, followed by a measure of working memory. The underlying cognitive mechanisms that lead to perseverations differ across tasks, with perseverations on the IF task reflecting both conceptual deficits and working memory limitations. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Any way you look at it, successful obstacle negotiation needs visually guided on-line foot placement regulation during the approach phase.

PubMed

Patla, Aftab E; Greig, Michael

In the two experiments discussed in this paper we quantified obstacle avoidance performance characteristics carried out open loop (without vision) but with different initial visual sampling conditions and compared it to the full vision condition. The initial visual sampling conditions included: static vision (SV), vision during forward walking for three steps and stopping (FW), vision during forward walking for three steps and not stopping (FW-NS), and vision during backward walking for three steps and stopping (BW). In experiment 1, we compared performance during SV, FW and BW with full vision condition, while in the second experiment we compared performance during FW and FW-NS conditions. The questions we wanted to address are: Is ecologically valid dynamic visual sampling of the environment superior to static visual sampling for open loop obstacle avoidance task? What are the reasons for failure in performing open loop obstacle avoidance task? The results showed that irrespective of the initial visual sampling condition when open loop control is initiated from a standing posture, the success rate was only approximately 50%. The main reason for the high failure rates was not inappropriate limb elevation, but incorrect foot placement before the obstacle. The second experiment showed that it is not the nature of visual sampling per se that influences success rate, but the fact that the open loop obstacle avoidance task is initiated from a standing posture. The results of these two experiments clearly demonstrate the importance of on-line visual information for adaptive human locomotion.

All framing effects are not created equal: Low convergent validity between two classic measurements of framing

PubMed Central

Zhen, Shanshan; Yu, Rongjun

2016-01-01

Human risk-taking attitudes can be influenced by two logically equivalent but descriptively different frames, termed the framing effect. The classic hypothetical vignette-based task (Asian disease problem) and a recently developed reward-based gambling task have been widely used to assess individual differences in the framing effect. Previous studies treat framing bias as a stable trait that has genetic basis. However, these two paradigms differ in terms of task domain (loss vs. gain) and task context (vignette-based vs. reward-based) and the convergent validity of these measurements remains unknown. Here, we developed a vignette-based task and a gambling task in both gain and loss domains and tested correlations of the framing effect among these tasks in 159 young adults. Our results revealed no significant correlation between the vignette-based task in the loss domain and the gambling task in the gain domain, indicating low convergent validity. The current findings raise the question of how to measure the framing effect precisely, especially in individual difference studies using large samples and expensive neuroscience methods. Our results suggest that the framing effect is influenced by both task domain and task context and future research should be cautious about the operationalization of the framing effect. PMID:27436680

All framing effects are not created equal: Low convergent validity between two classic measurements of framing.

PubMed

Zhen, Shanshan; Yu, Rongjun

2016-07-20

Human risk-taking attitudes can be influenced by two logically equivalent but descriptively different frames, termed the framing effect. The classic hypothetical vignette-based task (Asian disease problem) and a recently developed reward-based gambling task have been widely used to assess individual differences in the framing effect. Previous studies treat framing bias as a stable trait that has genetic basis. However, these two paradigms differ in terms of task domain (loss vs. gain) and task context (vignette-based vs. reward-based) and the convergent validity of these measurements remains unknown. Here, we developed a vignette-based task and a gambling task in both gain and loss domains and tested correlations of the framing effect among these tasks in 159 young adults. Our results revealed no significant correlation between the vignette-based task in the loss domain and the gambling task in the gain domain, indicating low convergent validity. The current findings raise the question of how to measure the framing effect precisely, especially in individual difference studies using large samples and expensive neuroscience methods. Our results suggest that the framing effect is influenced by both task domain and task context and future research should be cautious about the operationalization of the framing effect.

The Role of Inhibitory Control in Children's Cooperative Behaviors during a Structured Puzzle Task

ERIC Educational Resources Information Center

Giannotta, Fabrizia; Burk, William J.; Ciairano, Silvia

2011-01-01

This study examined the role of inhibitory control (measured by Stroop interference) in children's cooperative behaviors during a structured puzzle task. The sample consisted of 250 8-, 10-, and 12-year-olds (117 girls and 133 boys) attending classrooms in three primary schools in Northern Italy. Children individually completed an elaborated…

Generalizability of the Ordering among Five Formal Reasoning Tasks by an Ordering-Theoretic Method.

ERIC Educational Resources Information Center

Bart, William M.; And Others

1979-01-01

Five Inhelder-Piaget formal operations tasks were analyzed to determine the extent that the formal operational skills they assess were ordered into a stable hierarchy generalizable across samples of subjects. Subjects were 34 collegiate gymnasts (19 males, 15 females), and 22 students (1 male, 21 females) from a university nursing program.…

Convergent Validity of and Bias in Maternal Reports of Child Emotion

ERIC Educational Resources Information Center

Durbin, C. Emily; Wilson, Sylia

2012-01-01

This study examined the convergent validity of maternal reports of child emotion in a sample of 190 children between the ages of 3 and 6. Children completed a battery of 10 emotion-eliciting laboratory tasks; their mothers and untrained naive observers rated child emotions (happiness, surprise, fear, sadness, and anger) following each task, and…

"I Don't Really Understand Probability at All": Final Year Pre-Service Teachers' Understanding of Probability

ERIC Educational Resources Information Center

Maher, Nicole; Muir, Tracey

2014-01-01

This paper reports on one aspect of a wider study that investigated a selection of final year pre-service primary teachers' responses to four probability tasks. The tasks focused on foundational ideas of probability including sample space, independence, variation and expectation. Responses suggested that strongly held intuitions appeared to…

Quantitative Analysis of Language Production in Parkinson's Disease Using a Cued Sentence Generation Task

ERIC Educational Resources Information Center

Vanhoutte, Sarah; De Letter, Miet; Corthals, Paul; Van Borsel, John; Santens, Patrick

2012-01-01

The present study examined language production skills in Parkinson's disease (PD) patients. A unique cued sentence generation task was created in order to reduce demands on memory and attention. Differences in sentence production abilities according to disease severity and cognitive impairments were assessed. Language samples were obtained from 20…

The Role of Motivating Tasks and Personal Goal Orientations in Students' Coping Strategies in Science

ERIC Educational Resources Information Center

Subasi, Münevver; Tas, Yasemin

2016-01-01

This study aims to investigate coping strategies of middle school students in science classes in relation to students' goal orientations and motivating tasks conducted in the classroom environment. The study was conducted in spring semester of 2015-2016 academic year. Sample of the study consists of 316 middle school students receiving education…

Designing out Barriers to Student Access and Participation in Secondary School Assessment

ERIC Educational Resources Information Center

Graham, Linda J.; Tancredi, Haley; Willis, Jill; McGraw, Kelli

2018-01-01

In an effort to support student agency in assessment, teachers seek to provide detailed instructions and advice in associated assessment task sheets. In this paper, we analyse a sample English assessment task to consider how such assessment design practices might inadvertently create barriers to access and participation. To make our case, we…

Explaining and Controlling for the Psychometric Properties of Computer-Generated Figural Matrix Items

ERIC Educational Resources Information Center

Freund, Philipp Alexander; Hofer, Stefan; Holling, Heinz

2008-01-01

Figural matrix items are a popular task type for assessing general intelligence (Spearman's g). Items of this kind can be constructed rationally, allowing the implementation of computerized generation algorithms. In this study, the influence of different task parameters on the degree of difficulty in matrix items was investigated. A sample of N =…

Role of Mental Representations in Problem Solving: Students' Approaches to Nondirected Tasks

ERIC Educational Resources Information Center

Ibrahim, Bashirah; Rebello, N. Sanjay

2013-01-01

In this paper, we report on a project concerned with the role of cognition during problem solving. We specifically explore the categories of mental representations that students work with during problem solving of different representational task formats. The sample, consisting of 19 engineering students taking a calculus-based physics course,…

A Multilevel Study of Self-Beliefs and Student Behaviors in a Group Problem-Solving Task

ERIC Educational Resources Information Center

Hanham, José; McCormick, John

2018-01-01

Relationships among self-construal, self-efficacy, and group behaviors during a group problem-solving task with friends and acquaintances were hypothesized. The sample comprised 126 students in Grades 8-11, from 5 randomly selected government high schools, organized into 42 groups. Data collection involved self-reports and observations.…

Bilingual Phonological Awareness: Multilevel Construct Validation among Spanish-Speaking Kindergarteners in Transitional Bilingual Education Classrooms

ERIC Educational Resources Information Center

Branum-Martin, Lee; Mehta, Paras D.; Fletcher, Jack M.; Carlson, Coleen D.; Ortiz, Alba; Carlo, Maria; Francis, David J.

2006-01-01

The construct validity of English and Spanish phonological awareness (PA) tasks was examined with a sample of 812 kindergarten children from 71 transitional bilingual education program classrooms located in 3 different types of geographic regions in California and Texas. Tasks of PA, including blending nonwords, segmenting words, and phoneme…

Hippocampus Is Required for Paired Associate Memory with Neither Delay Nor Trial Uniqueness

ERIC Educational Resources Information Center

Yoon, Jinah; Seo, Yeran; Kim, Jangjin; Lee, Inah

2012-01-01

Cued retrieval of memory is typically examined with delay when testing hippocampal functions, as in delayed matching-to-sample tasks. Equally emphasized in the literature, on the other hand, is the hippocampal involvement in making arbitrary associations. Paired associate memory tasks are widely used for examining this function. However, the two…

Using Convergent and Divergent Tasks to Improve Writing and Language Learning Motivation

ERIC Educational Resources Information Center

Marashi, Hamid; Tahan-Shizari, Parissa

2015-01-01

This study was an attempt to investigate the comparative impact of convergent and divergent condition tasks on EFL learners' writing and motivation. Sixty female intermediate EFL learners were selected from among a total number of 90 through their performance on a sample piloted PET and further homogenized in terms of their writing and motivation.…

Empty Sets as Part of the Numerical Continuum: Conceptual Precursors to the Zero Concept in Rhesus Monkeys

ERIC Educational Resources Information Center

Merritt, Dustin J.; Rugani, Rosa; Brannon, Elizabeth M.

2009-01-01

The goal of the current research was to explore whether monkeys possess conceptual precursors necessary for understanding zero. We trained rhesus monkeys on a nonsymbolic numerical matching-to-sample task, and on a numerical ordering task. We then introduced nondifferentially reinforced trials that contained empty sets to determine whether monkeys…

Local and Global Visual Processing in Autism Spectrum Disorders: Influence of Task and Sample Characteristics and Relation to Symptom Severity

ERIC Educational Resources Information Center

Van Eylen, Lien; Boets, Bart; Steyaert, Jean; Wagemans, Johan; Noens, Ilse

2018-01-01

Local and global visual processing abilities and processing style were investigated in individuals with autism spectrum disorder (ASD) versus typically developing individuals, children versus adolescents and boys versus girls. Individuals with ASD displayed more attention to detail in daily life, while laboratory tasks showed slightly reduced…

Academic Self-Efficacy in the College Classroom: An Examination of Undergraduate Students' Reported Efficacy for Learning Tasks

ERIC Educational Resources Information Center

Conner, Timothy W., II; Aagaard, Lola; Skidmore, Ronald L.

2011-01-01

Self-efficacy is a personal belief in one's ability to accomplish particular tasks. Academic self-efficacy relates to one's belief in ability to accomplish learning activities. A convenient cluster sample (n = 105) of undergraduate students at a regional university in the midsouth was administered a survey that measured student academic…

Teachers' Difficulties in Preparation and Implementation of Performance Task

ERIC Educational Resources Information Center

Metin, Mustafa

2013-01-01

The aim of study is to determinate the difficulties of teachers in preparation and implementation of performance task. This study was carried out with 25 teachers (5 science and technology, 5 primary, 5 mathematic, 5 social science and 5 Turkish teachers) who working at elementary schools in Artvin. Sample of study is selected randomly. Case study…

Results of Hg speciation testing on DWPF SMECT-4, SMECT-6, and RCT-2 samples

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

Bannochie, C. J.

2016-02-04

The Savannah River National Laboratory (SRNL) was tasked with preparing and shipping samples for Hg speciation by Eurofins Frontier Global Sciences, Inc. in Seattle, WA on behalf of the Savannah River Remediation (SRR) Mercury Task Team.i,ii The fifteenth shipment of samples was designated to include Defense Waste Processing Facility (DWPF) Slurry Mix Evaporator Condensate Tank (SMECT) samples from Sludge Receipt and Adjustment Tank (SRAT) Batch 738 and a Recycle Condensate Tank (RCT) sample from SRAT Batch 736. The DWPF sample designations for the three samples analyzed are provided in Table 1. The Batch 738 ‘Baseline’ SMECT sample was taken priormore » to Precipitate Reactor Feed Tank (PRFT) addition and concentration and therefore, precedes the SMECT-5 sample reported previously. iii The Batch 738 ‘End of SRAT Cycle’ SMECT sample was taken at the conclusion of SRAT operations for this batch (PRFT addition/concentration, acid additions, initial concentration, MCU addition, and steam stripping). Batch 738 experienced a sludge slurry carryover event, which introduced sludge solids to the SMECT that were particularly evident in the SMECT-5 sample, but less evident in the ‘End of SRAT Cycle’ SMECT-6 sample. The Batch 736 ‘After SME’ RCT sample was taken after completion of SMECT transfers at the end of the SME cycle.« less

Empirical Validation of a Procedure to Correct Position and Stimulus Biases in Matching-to-Sample

ERIC Educational Resources Information Center

Kangas, Brian D.; Branch, Marc N.

2008-01-01

The development of position and stimulus biases often occurs during initial training on matching-to-sample tasks. Furthermore, without intervention, these biases can be maintained via intermittent reinforcement provided by matching-to-sample contingencies. The present study evaluated the effectiveness of a correction procedure designed to…

Children Prefer Diverse Samples for Inductive Reasoning in the Social Domain

ERIC Educational Resources Information Center

Noyes, Alexander; Christie, Stella

2016-01-01

Not all samples of evidence are equally conclusive: Diverse evidence is more representative than narrow evidence. Prior research showed that children did not use sample diversity in evidence selection tasks, indiscriminately choosing diverse or narrow sets (tiger-mouse; tiger-lion) to learn about animals. This failure is not due to a general…

Order of Stimulus Presentation Influences Children's Acquisition in Receptive Identification Tasks

ERIC Educational Resources Information Center

Petursdottir, Anna Ingeborg; Aguilar, Gabriella

2016-01-01

Receptive identification is usually taught in matching-to-sample format, which entails the presentation of an auditory sample stimulus and several visual comparison stimuli in each trial. Conflicting recommendations exist regarding the order of stimulus presentation in matching-to-sample trials. The purpose of this study was to compare acquisition…

Suggested Format and Content of a Work Sample Manual: [With Examples].

ERIC Educational Resources Information Center

Wisconsin Univ. - Stout, Menomonie. Dept. of Rehabilitation and Manpower Services. Materials Development Center.

Work samples are job tasks used as a diagnostic tool in the evaluation of vocational rehabilitation clients. The manual was developed to provide a standardized format for the construction, administration, and interpretation of necessary information from work sample assessment techniques used by vocational evaluators. The outline is divided into…

Technology Tips: Sample Too Small? Probably Not!

ERIC Educational Resources Information Center

Strayer, Jeremy F.

2013-01-01

Statistical studies are referenced in the news every day, so frequently that people are sometimes skeptical of reported results. Often, no matter how large a sample size researchers use in their studies, people believe that the sample size is too small to make broad generalizations. The tasks presented in this article use simulations of repeated…

Do Pigeons Prefer Information in the Absence of Differential Reinforcement?

PubMed Central

Zentall, Thomas R.; Stagner, Jessica P.

2012-01-01

Prior research indicates that pigeons do not prefer an alternative that provides a sample (for matching-to-sample) over an alternative that does not provide a sample (i.e., there is no indication of which comparison stimulus is correct). However, Zentall and Stagner (2010) showed that when delay of reinforcement was controlled, pigeons had a strong preference for matching over pseudo-matching (there was a sample but it did not indicate which comparison stimulus was correct). Experiment 1 of the present study replicated and extended the results of the Zentall and Stagner study by including an identity relation between the sample and one of the comparison stimuli in both the matching and pseudo-matching tasks. In Experiment 2, when we asked if the pigeons would still prefer matching if we equated the two tasks for probability of reinforcement, we found no systematic preference for matching over pseudo-matching. Thus, it appears that in the absence of differential reinforcement, the information provided by a sample that signals which of the two comparison stimuli is correct is insufficient to produce a preference for that alternative. PMID:22367755

A laboratory procedure for measuring and georeferencing soil colour

NASA Astrophysics Data System (ADS)

Marques-Mateu, A.; Balaguer-Puig, M.; Moreno-Ramon, H.; Ibanez-Asensio, S.

2015-04-01

Remote sensing and geospatial applications very often require ground truth data to assess outcomes from spatial analyses or environmental models. Those data sets, however, may be difficult to collect in proper format or may even be unavailable. In the particular case of soil colour the collection of reliable ground data can be cumbersome due to measuring methods, colour communication issues, and other practical factors which lead to a lack of standard procedure for soil colour measurement and georeferencing. In this paper we present a laboratory procedure that provides colour coordinates of georeferenced soil samples which become useful in later processing stages of soil mapping and classification from digital images. The procedure requires a laboratory setup consisting of a light booth and a trichromatic colorimeter, together with a computer program that performs colour measurement, storage, and colour space transformation tasks. Measurement tasks are automated by means of specific data logging routines which allow storing recorded colour data in a spatial format. A key feature of the system is the ability of transforming between physically-based colour spaces and the Munsell system which is still the standard in soil science. The working scheme pursues the automation of routine tasks whenever possible and the avoidance of input mistakes by means of a convenient layout of the user interface. The program can readily manage colour and coordinate data sets which eventually allow creating spatial data sets. All the tasks regarding data joining between colorimeter measurements and samples locations are executed by the software in the background, allowing users to concentrate on samples processing. As a result, we obtained a robust and fully functional computer-based procedure which has proven a very useful tool for sample classification or cataloging purposes as well as for integrating soil colour data with other remote sensed and spatial data sets.

Expressive writing and eating disorder features: a preliminary trial in a student sample of the impact of three writing tasks on eating disorder symptoms and associated cognitive, affective and interpersonal factors.

PubMed

East, Philippa; Startup, Helen; Roberts, Clifford; Schmidt, Ulrike

2010-05-01

To evaluate the impact of three writing tasks on the cognitive, affective and interpersonal factors typically associated with eating disorder symptoms, in a student population. Two experimental tasks and one control task were evaluated. Participants gave subjective ratings of the writing experience, and objective questionnaire measures were administered at baseline, and 4- and 8-week follow-up. Participants who dropped out without completing the writing tasks were more experientially avoidant. The three tasks differed significantly in subjective impact, and the experimental tasks were most effective in reducing eating disorder symptoms. They also ameliorated some key features associated with eating difficulties. The control task generally had less, no or a detrimental effect. The results provide preliminary indirect support for the use of therapeutic writing to address specific features associated with the eating disorder presentation. Further research is required to replicate the present findings and extend these to the clinical population. Copyright (c) 2010 John Wiley & Sons, Ltd and Eating Disorders Association.

Computerized assessment of sustained attention: interactive effects of task demand, noise, and anxiety.

PubMed

Ballard, J C

1996-12-01

In a sample of 163 college undergraduates, the effects of task demand, noise, and anxiety on Continuous Performance Test (CPT) errors were evaluated with multiple regression and multivariate analysis of variance. Results indicated significantly more omission errors on the difficult task. Complex interaction effects of noise and self-reported anxiety yielded more omissions in quiet intermittent white noise, particularly for high-anxious subjects performing the difficult task. Anxiety levels tended to increase from pretest to posttest, particularly for low-anxious subjects in the quiet, difficult-task condition, while a decrease was seen for high-anxious subjects in the loud, easy-task condition. Commission errors were unrelated to any predictor variables, suggesting that "attention" cannot be considered a unitary phenomenon. The variety of direct and interactive effects on vigilance performance underscore the need for clinicians to use a variety of measures to assess attentional skills, to avoid diagnosis of attention deficits on the basis of a single computerized task performance, and to rule out anxiety and other contributors to poor vigilance task performance.

Being right is its own reward: load and performance related ventral striatum activation to correct responses during a working memory task in youth.

PubMed

Satterthwaite, Theodore D; Ruparel, Kosha; Loughead, James; Elliott, Mark A; Gerraty, Raphael T; Calkins, Monica E; Hakonarson, Hakon; Gur, Ruben C; Gur, Raquel E; Wolf, Daniel H

2012-07-02

The ventral striatum (VS) is a critical brain region for reinforcement learning and motivation. Intrinsically motivated subjects performing challenging cognitive tasks engage reinforcement circuitry including VS even in the absence of external feedback or incentives. However, little is known about how such VS responses develop with age, relate to task performance, and are influenced by task difficulty. Here we used fMRI to examine VS activation to correct and incorrect responses during a standard n-back working memory task in a large sample (n=304) of healthy children, adolescents and young adults aged 8-22. We found that bilateral VS activates more strongly to correct than incorrect responses, and that the VS response scales with the difficulty of the working memory task. Furthermore, VS response was correlated with discrimination performance during the task, and the magnitude of VS response peaked in mid-adolescence. These findings provide evidence for scalable intrinsic reinforcement signals during standard cognitive tasks, and suggest a novel link between motivation and cognition during adolescent development. Copyright © 2012 Elsevier Inc. All rights reserved.

Food-specific response inhibition, dietary restraint and snack intake in lean and overweight/obese adults: a moderated-mediation model

PubMed Central

Price, M; Lee, M; Higgs, S

2016-01-01

Background/Objectives: The relationship between response inhibition and obesity is currently unclear. This may be because of inconsistencies in methodology, design limitations and the use of narrow samples. In addition, dietary restraint has not been considered, yet restraint has been reported to moderate performance on behavioural tasks of response inhibition. The aim of this study was to investigate performance on both a food-based and a neutral stimuli go/no-go task, which addresses current design limitations, in lean and overweight/obese adults. The moderating role of dietary restraint in the relationship between body composition, response inhibition and snack intake was also measured. Subjects/Methods: Lean and overweight/obese, males and females (N=116) completed both a food-based and neutral category control go/no-go task, in a fully counterbalanced repeated-measures design. A bogus taste-test was then completed, followed by a self-report measure of dietary restraint. Results: PROCESS moderated-mediation analysis showed that overweight/obese, compared with lean, participants made more errors on the food-based (but not the neutral) go/no-go task, but only when they were low in dietary restraint. Performance on the food-based go/no-go task predicted snack intake across the sample. Increased intake in the overweight, low restrainers was fully mediated by increased errors on the food-based (but not the neutral) go/no-go task. Conclusions: Distinguishing between high and low restrained eaters in the overweight/obese population is crucial in future obesity research incorporating food-based go/no-go tasks. Poor response inhibition to food cues predicts overeating across weight groups, suggesting weight loss interventions and obesity prevention programmes should target behavioural inhibition training in such individuals. PMID:26592733

Food-specific response inhibition, dietary restraint and snack intake in lean and overweight/obese adults: a moderated-mediation model.

PubMed

Price, M; Lee, M; Higgs, S

2016-05-01

The relationship between response inhibition and obesity is currently unclear. This may be because of inconsistencies in methodology, design limitations and the use of narrow samples. In addition, dietary restraint has not been considered, yet restraint has been reported to moderate performance on behavioural tasks of response inhibition. The aim of this study was to investigate performance on both a food-based and a neutral stimuli go/no-go task, which addresses current design limitations, in lean and overweight/obese adults. The moderating role of dietary restraint in the relationship between body composition, response inhibition and snack intake was also measured. Lean and overweight/obese, males and females (N=116) completed both a food-based and neutral category control go/no-go task, in a fully counterbalanced repeated-measures design. A bogus taste-test was then completed, followed by a self-report measure of dietary restraint. PROCESS moderated-mediation analysis showed that overweight/obese, compared with lean, participants made more errors on the food-based (but not the neutral) go/no-go task, but only when they were low in dietary restraint. Performance on the food-based go/no-go task predicted snack intake across the sample. Increased intake in the overweight, low restrainers was fully mediated by increased errors on the food-based (but not the neutral) go/no-go task. Distinguishing between high and low restrained eaters in the overweight/obese population is crucial in future obesity research incorporating food-based go/no-go tasks. Poor response inhibition to food cues predicts overeating across weight groups, suggesting weight loss interventions and obesity prevention programmes should target behavioural inhibition training in such individuals.

Early conversational environment enables spontaneous belief attribution in deaf children.

PubMed

Meristo, Marek; Strid, Karin; Hjelmquist, Erland

2016-12-01

Previous research suggests that deaf children who grow up with hearing parents display considerable difficulties in understanding mental states of others, up to their teenage years when explicitly asked in a verbal test situation (Meristo et al., 2007). On the other hand, typically developing pre-verbal infants display evidence of spontaneous false belief attribution when tested in looking-time tasks, although verbal tests are typically not passed before the age of 4years (Onishi & Baillargeon, 2005). The purpose of the present study was to examine whether deaf children of hearing parents are able to demonstrate spontaneous belief attribution in a non-verbal eye-tracking task. Thirty 4- to 8-year-old, deaf and hearing children, completed a non-verbal spontaneous-response false-belief task and a verbal elicited-response false-belief task. The deaf children were either children with cochlear implants or children with hearing aids. Comparative analyses were also carried out with a previous sample of deaf and hearing 2-year-olds (reported in Meristo, Morgan, et al., 2012). We found that in the non-verbal spontaneous-response task typically hearing children, but not deaf children, were able to predict that a person with a false belief about an object's location will search erroneously for the object. However, hearing children and deaf children with implants, but not deaf children with hearing aids, passed the verbal elicited-response task. Language development was significantly correlated with both types of false-belief tasks for the whole sample. Our findings strengthen the hypothesis that the emergence of the ability to recognize others' beliefs needs to be supported initially by very early conversational input in dialogues with caregivers. Copyright © 2016 Elsevier B.V. All rights reserved.

Maternal immune activation during pregnancy in rats impairs working memory capacity of the offspring.

PubMed

Murray, Brendan G; Davies, Don A; Molder, Joel J; Howland, John G

2017-05-01

Maternal immune activation during pregnancy is an environmental risk factor for psychiatric illnesses such as schizophrenia in the offspring. Patients with schizophrenia display an array of cognitive symptoms, including impaired working memory capacity. Rodent models have been developed to understand the relationship between maternal immune activation and the cognitive symptoms of schizophrenia. The present experiment was designed to test whether maternal immune activation with the viral mimetic polyinosinic:polycytidylic acid (polyI:C) during pregnancy affects working memory capacity of the offspring. Pregnant Long Evans rats were treated with either saline or polyI:C (4mg/kg; i.v.) on gestational day 15. Male offspring of the litters (2-3months of age) were subsequently trained on a nonmatching-to-sample task with odors. After a criterion was met, the rats were tested on the odor span task, which requires rats to remember an increasing span of different odors to receive food reward. Rats were tested using delays of approximately 40s during the acquisition of the task. Importantly, polyI:C- and saline-treated offspring did not differ in performance of the nonmatching-to-sample task suggesting that both groups could perform a relatively simple working memory task. In contrast, polyI:C-treated offspring had reduced span capacity in the middle and late phases of odor span task acquisition. After task acquisition, the rats were tested using the 40s delay and a 10min delay. Both groups showed a delay-dependent decrease in span, although the polyI:C-treated offspring had significantly lower spans regardless of delay. Our results support the validity of the maternal immune activation model for studying the cognitive symptoms of neurodevelopmental disorders such as schizophrenia. Copyright © 2017 Elsevier Inc. All rights reserved.

Telephone Assessment and Skill-Building Kit for Stroke Caregivers: A Randomized Controlled Clinical Trial.

PubMed

Bakas, Tamilyn; Austin, Joan K; Habermann, Barbara; Jessup, Nenette M; McLennon, Susan M; Mitchell, Pamela H; Morrison, Gwendolyn; Yang, Ziyi; Stump, Timothy E; Weaver, Michael T

2015-12-01

There are few evidence-based programs for stroke family caregivers postdischarge. The purpose of this study was to evaluate efficacy of the Telephone Assessment and Skill-Building Kit (TASK II), a nurse-led intervention enabling caregivers to build skills based on assessment of their own needs. A total of 254 stroke caregivers (primarily female TASK II/information, support, and referral 78.0%/78.6%; white 70.7%/72.1%; about half spouses 48.4%/46.6%) were randomized to the TASK II intervention (n=123) or to an information, support, and referral group (n=131). Both groups received 8 weekly telephone sessions, with a booster at 12 weeks. General linear models with repeated measures tested efficacy, controlling for patient hospital days and call minutes. Prespecified 8-week primary outcomes were depressive symptoms (with Patient Health Questionnaire Depressive Symptom Scale PHQ-9 ≥5), life changes, and unhealthy days. Among caregivers with baseline PHQ-9 ≥5, those randomized to the TASK II intervention had a greater reduction in depressive symptoms from baseline to 8, 24, and 52 weeks and greater improvement in life changes from baseline to 12 weeks compared with the information, support, and referral group (P<0.05); but not found for the total sample. Although not sustained at 12, 24, or 52 weeks, caregivers randomized to the TASK II intervention had a relatively greater reduction in unhealthy days from baseline to 8 weeks (P<0.05). The TASK II intervention reduced depressive symptoms and improved life changes for caregivers with mild to severe depressive symptoms. The TASK II intervention reduced unhealthy days for the total sample, although not sustained over the long term. URL: https://www.clinicaltrials.gov. Unique identifier: NCT01275495. © 2015 American Heart Association, Inc.

Optical Fabrication and Measurement AXAF and CIRS

NASA Technical Reports Server (NTRS)

Engelhaupt, Darell

1997-01-01

This paper presents a final report on Optical Fabrication and Measurement AXAF (Advanced X-Ray Astrophysics Facility) and CIRS (Composite Infrared Spectrometer) from July 12, 1994 to August 16, 1996.. This paper includes specific tasks to be performed. The tasks are as follows: 1) Preparation and Characterization of Zerodur Glass Samples; 2) Develop and Fabricate AXAF and CIRS Metrology Tooling; 3) Update AXAF Technical Data Base; and 4) Perform Fabrication Related Metrology Tasks for CIRS. This paper also includes final activities from the July, 1996 report to August 1996.

Illegitimate Tasks as an Impediment to Job Satisfaction and Intrinsic Motivation: Moderated Mediation Effects of Gender and Effort-Reward Imbalance

PubMed Central

Omansky, Rachel; Eatough, Erin M.; Fila, Marcus J.

2016-01-01

The current work examines a contemporary workplace stressor that has only recently been introduced into the literature: illegitimate tasks. Illegitimate tasks are work tasks that violate identity role norms about what can reasonably be expected from an employee in a given position. Although illegitimate tasks have been linked to employee well-being in past work, we know little about the potential explanatory mechanisms linking illegitimate tasks to work-relevant negative psychological states. Using a sample of 213 US-based employees of mixed occupations and a cross-sectional design, the present study examines job satisfaction and intrinsic motivation as outcomes of illegitimate tasks. Additionally, we examine perception of effort-reward imbalance (ERI) as a potential mediating mechanism through which illegitimate tasks relate to job satisfaction and intrinsic motivation, highlighting a possible pathway by which these relationships are functioning. Finally, we explore gender as a socially constructed variable that could contribute to variation in responses to illegitimate tasks and moderate the mediated link between illegitimate tasks and outcomes. Results indicated that illegitimate tasks were significantly related to job satisfaction and intrinsic motivation both directly and indirectly through perceptions of ERI in the predicted directions. Moreover, a moderated-mediation effect was found such that male workers reacted more than female workers to illegitimate tasks through the mechanism of perceived ERI. PMID:27917145

Illegitimate Tasks as an Impediment to Job Satisfaction and Intrinsic Motivation: Moderated Mediation Effects of Gender and Effort-Reward Imbalance.

PubMed

Omansky, Rachel; Eatough, Erin M; Fila, Marcus J

2016-01-01

The current work examines a contemporary workplace stressor that has only recently been introduced into the literature: illegitimate tasks. Illegitimate tasks are work tasks that violate identity role norms about what can reasonably be expected from an employee in a given position. Although illegitimate tasks have been linked to employee well-being in past work, we know little about the potential explanatory mechanisms linking illegitimate tasks to work-relevant negative psychological states. Using a sample of 213 US-based employees of mixed occupations and a cross-sectional design, the present study examines job satisfaction and intrinsic motivation as outcomes of illegitimate tasks. Additionally, we examine perception of effort-reward imbalance (ERI) as a potential mediating mechanism through which illegitimate tasks relate to job satisfaction and intrinsic motivation, highlighting a possible pathway by which these relationships are functioning. Finally, we explore gender as a socially constructed variable that could contribute to variation in responses to illegitimate tasks and moderate the mediated link between illegitimate tasks and outcomes. Results indicated that illegitimate tasks were significantly related to job satisfaction and intrinsic motivation both directly and indirectly through perceptions of ERI in the predicted directions. Moreover, a moderated-mediation effect was found such that male workers reacted more than female workers to illegitimate tasks through the mechanism of perceived ERI.

Tackling creativity at its roots: Evidence for different patterns of EEG alpha activity related to convergent and divergent modes of task processing

PubMed Central

Jauk, Emanuel; Benedek, Mathias; Neubauer, Aljoscha C.

2012-01-01

The distinction between convergent and divergent cognitive processes given by Guilford (1956) had a strong influence on the empirical research on creative thinking. Neuroscientific studies typically find higher event-related synchronization in the EEG alpha rhythm for individuals engaged in creative ideation tasks compared to intelligence-related tasks. This study examined, whether these neurophysiological effects can also be found when both cognitive processing modes (convergent vs. divergent) are assessed by means of the same task employing a simple variation of instruction. A sample of 55 participants performed the alternate uses task as well as a more basic word association task while EEG was recorded. On a trial-by-trial basis, participants were either instructed to find a most common solution (convergent condition) or a most uncommon solution (divergent condition). The answers given in the divergent condition were in both tasks significantly more original than those in the convergent condition. Moreover, divergent processing was found to involve higher task-related EEG alpha power than convergent processing in both the alternate uses task and the word association task. EEG alpha synchronization can hence explicitly be associated with divergent cognitive processing rather than with general task characteristics of creative ideation tasks. Further results point to a differential involvement of frontal and parietal cortical areas by individuals of lower versus higher trait creativity. PMID:22390860

Hydrogen Safety Project: Chemical analysis support task. Window ``E`` analyses

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

Jones, T E; Campbell, J A; Hoppe, E W

1992-09-01

Core samples taken from tank 101-SY at Hanford during ``window E`` were analyzed for organic and radiochemical constituents by staff of the Analytical Chemistry Laboratory at Pacific Northwest Laboratory. Westinghouse Hanford company submitted these samples to the laboratory.

X-Ray Imaging Applied to Problems in Planetary Materials

NASA Technical Reports Server (NTRS)

Jurewicz, A. J. G.; Mih, D. T.; Jones, S. M.; Connolly, H.

2000-01-01

Real-time radiography (X-ray imaging) can be a useful tool for tasks such as (1) the non-destructive, preliminary examination of opaque samples and (2) optimizing how to section opaque samples for more traditional microscopy and chemical analysis.

Forgiveness, Ego-Integrity, and Depressive Symptoms in Community-Dwelling and Residential Elderly Adults.

PubMed

Dezutter, Jessie; Toussaint, Loren; Leijssen, Mia

2016-09-01

This study aimed first, to investigate the relation between forgivingness and depressive symptoms in elderly individuals and second, to explore whether the developmental task of integrity/despair is a possible underlying process in this relation. Both aims were studied in a sample of community-dwelling elderly individuals as well as in a sample of residential elderly individuals. Community-dwelling elderly individuals (n = 280, M = 75.98 years) and residential elderly individuals (n = 205, M = 83.20 years) in Belgium filled out questionnaires on forgivingness, depressive symptoms, and the developmental task of integrity/despair. Structural equation modeling was used to test the mediational role of integrity/despair in the relation between forgivingness and depression in both samples. Furthermore, multigroup analyses tested the convergence of the mediational models in the community-dwelling elderly individuals and the residential elderly individuals. Forgivingness and depression were negatively associated in both residential elderly individuals and community-dwelling elderly individuals. The developmental task of finding integrity and avoiding despair showed to be a significant mediator in this relationship. Framed within a life-span perspective, we showed that the developmental task of finding a balance between integrity and despair is an important intrapersonal mechanism through which forgivingness is related with depressed feelings for residential as well as community-dwelling elderly individuals. © 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.

Mind-wandering, cognition, and performance: a theory-driven meta-analysis of attention regulation.

PubMed

Randall, Jason G; Oswald, Frederick L; Beier, Margaret E

2014-11-01

The current meta-analysis accumulates empirical findings on the phenomenon of mind-wandering, integrating and interpreting findings in light of psychological theories of cognitive resource allocation. Cognitive resource theory emphasizes both individual differences in attentional resources and task demands together to predict variance in task performance. This theory motivated our conceptual and meta-analysis framework by introducing moderators indicative of task-demand to predict who is more likely to mind-wander under what conditions, and to predict when mind-wandering and task-related thought are more (or less) predictive of task performance. Predictions were tested via a random-effects meta-analysis of correlations obtained from normal adult samples (k = 88) based on measurement of specified episodes of off-task and/or on-task thought frequency and task performance. Results demonstrated that people with fewer cognitive resources tend to engage in more mind-wandering, whereas those with more cognitive resources are more likely to engage in task-related thought. Addressing predictions of resource theory, we found that greater time-on-task-although not greater task complexity-tended to strengthen the negative relation between cognitive resources and mind-wandering. Additionally, increases in mind-wandering were generally associated with decreases in task performance, whereas increases in task-related thought were associated with increased performance. Further supporting resource theory, the negative relation between mind-wandering and performance was more pronounced for more complex tasks, though not longer tasks. Complementarily, the positive association between task-related thought and performance was stronger for more complex tasks and for longer tasks. We conclude by discussing implications and future research directions for mind-wandering as a construct of interest in psychological research. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

Quantum Inference on Bayesian Networks

NASA Astrophysics Data System (ADS)

Yoder, Theodore; Low, Guang Hao; Chuang, Isaac

2014-03-01

Because quantum physics is naturally probabilistic, it seems reasonable to expect physical systems to describe probabilities and their evolution in a natural fashion. Here, we use quantum computation to speedup sampling from a graphical probability model, the Bayesian network. A specialization of this sampling problem is approximate Bayesian inference, where the distribution on query variables is sampled given the values e of evidence variables. Inference is a key part of modern machine learning and artificial intelligence tasks, but is known to be NP-hard. Classically, a single unbiased sample is obtained from a Bayesian network on n variables with at most m parents per node in time (nmP(e) - 1 / 2) , depending critically on P(e) , the probability the evidence might occur in the first place. However, by implementing a quantum version of rejection sampling, we obtain a square-root speedup, taking (n2m P(e) -1/2) time per sample. The speedup is the result of amplitude amplification, which is proving to be broadly applicable in sampling and machine learning tasks. In particular, we provide an explicit and efficient circuit construction that implements the algorithm without the need for oracle access.

Installation Restoration General Environmental Technology Development. Task 6. Materials Handling of Explosive Contaminated Soil and Sediment.

DTIC Science & Technology

1985-06-01

of chemical analysis and sensitivity testing on material samples . At this 4 time, these samples must be packaged and...preparation at a rate of three samples per hour. One analyst doing both sample preparation and the HPLC analysis can run 16 samples in an 8-hour day. II... study , sensitivity testing was reviewed to enable recommendations for complete analysis of contaminated soils. Materials handling techniques,

Is Mathematical Anxiety Always Bad for Math Learning: The Role of Math Motivation

PubMed Central

Wang, Zhe; Lukowski, Sarah L.; Hart, Sara Ann; Lyons, Ian M.; Thompson, Lee A.; Kovas, Yulia; Mazzocco, Michèle M.; Plomin, Robert; Petrill, Stephen A.

2015-01-01

The linear relations between math anxiety and math cognition have been frequently studied. However, the relations between anxiety and performance on complex cognitive tasks have been repeatedly demonstrated to follow a curvilinear fashion. Given the lack of attention to the possibility of such complex interplay between emotion and cognition in the math learning literature, the current study aimed to address this gap via exploring the relations between math anxiety, math motivation, and math cognition. The current study consisted of two samples. One sample included 262 pairs of young adolescent twins and the other included 237 adult college students. Participants self-reported their math anxiety and math motivation. Math cognition was assessed using a comprehensive battery of mathematics tasks. In both samples, results showed inverted-U relations between math anxiety and math performance in students with high intrinsic math motivation, and modest negative associations between math anxiety and math performance in students with low intrinsic math motivation. However, this pattern was not observed in tasks assessing student’s nonsymbolic and symbolic number estimation. These findings may help advance our understanding of mathematics learning processes and may provide important insights for treatment programs that target improving mathematics learning experiences and mathematical skills. PMID:26518438

Refining the multisystem view of the stress response: Coordination among cortisol, alpha-amylase, and subjective stress in response to relationship conflict

PubMed Central

Powers, Sally I.; Granger, Douglas A.

2013-01-01

This study investigated associations among young adults' hypothalamic-pituitary-adrenal axis activity, autonomic nervous system activity, and subjective stress in response to interpersonal conflict to better characterize coordination across stress systems. Seven saliva samples were collected from 199 young adult opposite-sex couples before, during, and after they discussed an unresolved relationship conflict. Samples were later assayed for cortisol and alpha-amylase (sAA). Couples rated anticipatory stress prior to the conflict and perceived stress immediately following the task. Growth curve modeling was used to examine two possible levels of within-person coordination across physiological systems: alignment between cortisol and sAA responses throughout the sampling period (“matched phase coordination”), and association between overall levels of cortisol and sAA in response to conflict (“average level coordination”). Whereas both partners showed the former type of coordination, only women showed the latter type. Positive anticipation of the stressor predicted stronger cortisol-sAA matched phase coordination for women. Pre-task ratings related to women's sAA, and post-task ratings related to both partners' cortisol responses. Implications for a multisystem interpretation of normal and pathological responses to daily stress are discussed. PMID:23684904

NEEMO 18-20: Analog Testing for Mitigation of Communication Latency During Human Space Exploration

NASA Technical Reports Server (NTRS)

Chappell, Steven P.; Beaton, Kara H.; Miller, Matthew J.; Graff, Trevor G.; Abercromby, Andrew F. J.; Gernhardt, Michael L.; Halcon, Christopher

2016-01-01

NASA Extreme Environment Mission Operations (NEEMO) is an underwater spaceflight analog that allows a true mission-like operational environment and uses buoyancy effects and added weight to simulate different gravity levels. Three missions were undertaken from 2014-2015, NEEMO's 18-20. All missions were performed at the Aquarius undersea research habitat. During each mission, the effects of communication latencies on operations concepts, timelines, and tasks were studied. METHODS: Twelve subjects (4 per mission) were weighed out to simulate near-zero or partial gravity extravehicular activity (EVA) and evaluated different operations concepts for integration and management of a simulated Earth-based science team (ST) to provide input and direction during exploration activities. Exploration traverses were preplanned based on precursor data. Subjects completed science-related tasks including pre-sampling surveys, geologic-based sampling, and marine-based sampling as a portion of their tasks on saturation dives up to 4 hours in duration that were designed to simulate extravehicular activity (EVA) on Mars or the moons of Mars. One-way communication latencies, 5 and 10 minutes between space and mission control, were simulated throughout the missions. Objective data included task completion times, total EVA times, crew idle time, translation time, ST assimilation time (defined as time available for ST to discuss data/imagery after data acquisition). Subjective data included acceptability, simulation quality, capability assessment ratings, and comments. RESULTS: Precursor data can be used effectively to plan and execute exploration traverse EVAs (plans included detailed location of science sites, high-fidelity imagery of the sites, and directions to landmarks of interest within a site). Operations concepts that allow for pre-sampling surveys enable efficient traverse execution and meaningful Mission Control Center (MCC) interaction across communication latencies and can be done with minimal crew idle time. Imagery and contextual information from the EVA crew that is transmitted real-time to the intravehicular (IV) crewmember(s) can be used to verify that exploration traverse plans are being executed correctly. That same data can be effectively used by MCC (across comm latency) to provide meaningful feedback and instruction to the crew regarding sampling priorities, additional tasks, and changes to the EVA timeline. Text / data capabilities are preferred over voice capabilities between MCC and IV when executing exploration traverse plans over communication latency.

Dissociations and Associations of Performance in Syntactic Comprehension in Aphasia and their Implications for the Nature of Aphasic Deficits

PubMed Central

Caplan, David; Michaud, Jennifer; Hufford, Rebecca

2013-01-01

Sixty one pwa were tested on syntactic comprehension in three tasks: sentence-picture matching, sentence-picture matching with auditory moving window presentation, and object manipulation. There were significant correlations of performances on sentences across tasks. First factors in unrotated factor analyses accounted for most of the variance on which all sentence types loaded in each task. Dissociations in performance between sentence types that differed minimally in their syntactic structures were not consistent across tasks. These results replicate previous results with smaller samples and provide important validation of basic aspects of aphasic performance in this area of language processing. They point to the role of a reduction in processing resources and of the interaction of task demands and parsing and interpretive abilities in the genesis of patient performance. PMID:24061104

The relationship between sustained inattentional blindness and working memory capacity.

PubMed

Beanland, Vanessa; Chan, Esther Hiu Chung

2016-04-01

Inattentional blindness, whereby observers fail to detect unexpected stimuli, has been robustly demonstrated in a range of situations. Originally research focused primarily on how stimulus characteristics and task demands affect inattentional blindness, but increasingly studies are exploring the influence of observer characteristics on the detection of unexpected stimuli. It has been proposed that individual differences in working memory capacity predict inattentional blindness, on the assumption that higher working memory capacity confers greater attentional capacity for processing unexpected stimuli. Unfortunately, empirical investigations of the association between inattentional blindness and working memory capacity have produced conflicting findings. To help clarify this relationship, we examined the relationship between inattentional blindness and working memory capacity in two samples (Ns = 195, 147) of young adults. We used three common variants of sustained inattentional blindness tasks, systematically manipulating the salience of the unexpected stimulus and primary task practice. Working memory capacity, measured by automated operation span (both Experiments 1 & 2) and N-back (Experiment 1 only) tasks, did not predict detection of the unexpected stimulus in any of the inattentional blindness tasks tested. Together with previous research, this undermines claims that there is a robust relationship between inattentional blindness and working memory capacity. Rather, it appears that any relationship between inattentional blindness and working memory is either too small to have practical significance or is moderated by other factors and consequently varies with attributes such as the sample characteristics within a given study.

Cooperative processing in primary somatosensory cortex and posterior parietal cortex during tactile working memory.

PubMed

Ku, Yixuan; Zhao, Di; Bodner, Mark; Zhou, Yong-Di

2015-08-01

In the present study, causal roles of both the primary somatosensory cortex (SI) and the posterior parietal cortex (PPC) were investigated in a tactile unimodal working memory (WM) task. Individual magnetic resonance imaging-based single-pulse transcranial magnetic stimulation (spTMS) was applied, respectively, to the left SI (ipsilateral to tactile stimuli), right SI (contralateral to tactile stimuli) and right PPC (contralateral to tactile stimuli), while human participants were performing a tactile-tactile unimodal delayed matching-to-sample task. The time points of spTMS were 300, 600 and 900 ms after the onset of the tactile sample stimulus (duration: 200 ms). Compared with ipsilateral SI, application of spTMS over either contralateral SI or contralateral PPC at those time points significantly impaired the accuracy of task performance. Meanwhile, the deterioration in accuracy did not vary with the stimulating time points. Together, these results indicate that the tactile information is processed cooperatively by SI and PPC in the same hemisphere, starting from the early delay of the tactile unimodal WM task. This pattern of processing of tactile information is different from the pattern in tactile-visual cross-modal WM. In a tactile-visual cross-modal WM task, SI and PPC contribute to the processing sequentially, suggesting a process of sensory information transfer during the early delay between modalities. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

The Impact of Help Seeking on Individual Task Performance: The Moderating Effect of Help Seekers' Logics of Action

ERIC Educational Resources Information Center

Geller, Dvora; Bamberger, Peter A.

2012-01-01

Drawing from achievement-goal theory and the social psychological literature on help seeking, we propose that it is the variance in the logic underpinning employees' help seeking that explains divergent findings regarding the relationship between help seeking and task performance. Using a sample of 110 newly hired customer contact employees, a…

The Magic Number 70 (Plus or Minus 20): Variables Determining Performance in the Rodent Odor Span Task

ERIC Educational Resources Information Center

April, L. Brooke; Bruce, Katherine; Galizio, Mark

2013-01-01

The olfactory span task (OST) uses an incrementing non-matching to sample procedure such that the number of stimuli to remember increases during the session. The number of consecutive correct responses (span length) and percent correct as a function of the memory load have been viewed as defining rodent working memory capacity limitations in…

What Influences Principals' Perceptions of Academic Climate? A Nationally Representative Study of the Direct Effects of Perception on Climate

ERIC Educational Resources Information Center

Urick, Angela; Bowers, Alex J.

2011-01-01

Using a nationally representative sample of public high schools (N = 439), we examined the extent to which the principal's perception of their influence over instruction, the evaluation of nonacademic related tasks as well as academic related tasks, and their relationship with the school district relates to their perception of academic climate…

Limitations in 4-Year-Old Children's Sensitivity to the Spacing among Facial Features

ERIC Educational Resources Information Center

Mondloch, Catherine J.; Thomson, Kendra

2008-01-01

Four-year-olds' sensitivity to differences among faces in the spacing of features was tested under 4 task conditions: judging distinctiveness when the external contour was visible and when it was occluded, simultaneous match-to-sample, and recognizing the face of a friend. In each task, the foil differed only in the spacing of features, and…

Running High-Throughput Jobs on Peregrine | High-Performance Computing |

Science.gov Websites

unique name (using "name=") and usse the task name to create a unique output file name. For runs on and how many tasks to give to each worker at a time using the NITRO_COORD_OPTIONS environment . Finally, you start Nitro by executing launch_nitro.sh. Sample Nitro job script To run a job using the

Trainee and Instructor Task Quantification: Development of Quantitative Indices and a Predictive Methodology.

ERIC Educational Resources Information Center

Whaton, George R.; And Others

As the first step in a program to develop quantitative techniques for prescribing the design and use of training systems, the present study attempted: to compile an initial set of quantitative indices, to determine whether these indices could be used to describe a sample of trainee tasks and differentiate among them, to develop a predictive…

Scaffolding under the Microscope: Applying Self-Regulation and Other-Regulation Perspectives to a Scaffolded Task

ERIC Educational Resources Information Center

Leith, Georgia; Yuill, Nicola; Pike, Alison

2018-01-01

Background: Typical scaffolding coding schemes provide overall scores to compare across a sample. As such, insights into the scaffolding process can be obscured: the child's contribution to the learning; the particular skills being taught and learned; and the overall changes in amount of scaffolding over the course of the task. Aims: This study…

Relating Difficulty in School Mathematics to Nature of Mathematics: Perception of High School Students from Kerala

ERIC Educational Resources Information Center

Gafoor, Kunnathodi Abdul; Sarabi, M. K.

2015-01-01

This study relates factors in nature of Mathematics and its teaching learning to student difficulties for diverse mathematics tasks. Descriptive survey was done on a sample of 300 high school students in Kerala with a questionnaire on difficulties in learning. Student perception of difficulty on 26 types of tasks, under five heads that students…

Developing the Impossible Figures Task to Assess Visual-Spatial Talents among Chinese Students: A Rasch Measurement Model Analysis

ERIC Educational Resources Information Center

Chan, David W.

2010-01-01

Data of item responses to the Impossible Figures Task (IFT) from 492 Chinese primary, secondary, and university students were analyzed using the dichotomous Rasch measurement model. Item difficulty estimates and person ability estimates located on the same logit scale revealed that the pooled sample of Chinese students, who were relatively highly…

Facilitation of memory encoding in primate hippocampus by a neuroprosthesis that promotes task-specific neural firing

NASA Astrophysics Data System (ADS)

Hampson, Robert E.; Song, Dong; Opris, Ioan; Santos, Lucas M.; Shin, Dae C.; Gerhardt, Greg A.; Marmarelis, Vasilis Z.; Berger, Theodore W.; Deadwyler, Sam A.

2013-12-01

Objective. Memory accuracy is a major problem in human disease and is the primary factor that defines Alzheimer’s, ageing and dementia resulting from impaired hippocampal function in the medial temporal lobe. Development of a hippocampal memory neuroprosthesis that facilitates normal memory encoding in nonhuman primates (NHPs) could provide the basis for improving memory in human disease states. Approach. NHPs trained to perform a short-term delayed match-to-sample (DMS) memory task were examined with multi-neuron recordings from synaptically connected hippocampal cell fields, CA1 and CA3. Recordings were analyzed utilizing a previously developed nonlinear multi-input multi-output (MIMO) neuroprosthetic model, capable of extracting CA3-to-CA1 spatiotemporal firing patterns during DMS performance. Main results. The MIMO model verified that specific CA3-to-CA1 firing patterns were critical for the successful encoding of sample phase information on more difficult DMS trials. This was validated by the delivery of successful MIMO-derived encoding patterns via electrical stimulation to the same CA1 recording locations during the sample phase which facilitated task performance in the subsequent, delayed match phase, on difficult trials that required more precise encoding of sample information. Significance. These findings provide the first successful application of a neuroprosthesis designed to enhance and/or repair memory encoding in primate brain.

Auditory memory in monkeys: costs and benefits of proactive interference.

PubMed

Bigelow, James; Poremba, Amy

2013-05-01

Proactive interference (PI) has traditionally been understood as an adverse consequence of stimulus repetition during memory tasks. Herein, we present data that emphasize costs as well as benefits of PI for monkeys performing an auditory delayed matching-to-sample (DMTS) task. The animals made same/different judgments for a variety of simple and complex sounds separated by a 5-s memory delay. Each session used a stimulus set that included eight sounds; thus, each sound was repeated multiple times per session for match trials and for nonmatch trials as the sample (Cue 1) or test (Cue 2) stimulus. For nonmatch trials, performance was substantially diminished when the test stimulus had been previously presented on a recent trial. However, when the sample stimulus had been recently presented, performance was significantly improved. We also observed a marginal performance benefit when stimuli for match trials had been recently presented. The costs of PI for nonmatch test stimuli were greater than the combined benefits of PI for nonmatch sample stimuli and match trials, indicating that the net influence of PI is detrimental. For all three manifestations of PI, the effects are shown to extend beyond the immediately subsequent trial. Our data suggest that PI in auditory DMTS is best understood as an enduring influence that can be both detrimental and beneficial to memory-task performance. © 2012 Wiley Periodicals, Inc.

Dropout in looking time studies: The role of infants' temperament and cognitive developmental status.

PubMed

Klein-Radukic, Sarah; Zmyj, Norbert

2015-11-01

Dropout of infants in looking time studies sometimes occurs at high rates, raising concerns that the representativeness of the final sample might be reduced in comparison to the originally obtained sample. The current study investigated which infant characteristics play a role in dropout. Infants were presented with a preferential looking task at 6 and 9 months of age. At 9 months of age, an additional habituation task and a subsequent novelty preference task were conducted. In addition, temperament was assessed via the Infant Behavior Questionnaire - Revised (IBQ-R, Gartstein & Rothbart, 2003), and cognitive developmental status was assessed via the Cognitive Scale of the Bayley Scale of Infant and Toddler Development (BSID-III, Bayley, 2006). Dropout was positively related to the IBQ-R temperament scales Distress to Limitations and Approach, and negatively related to the scales Falling Reactivity and Cuddliness. The representativeness of the final sample regarding situation-specific temperament dimensions is affected by dropout. Dropout was not related to cognitive developmental status as measured via the BSID-III, habituation speed and novelty preference. Dropout at 6 months of age was associated with dropout at 9 months of age. We concluded that in looking time studies, the representativeness of the final sample regarding performance-relevant temperament dimensions or cognitive developmental status is not affected by dropout. Copyright © 2015 Elsevier Inc. All rights reserved.

Facilitation of Memory Encoding in Primate Hippocampus by a Neuroprosthesis that Promotes Task Specific Neural Firing

PubMed Central

Hampson, Robert E.; Song, Dong; Opris, Ioan; Santos, Lucas M.; Shin, Dae C.; Gerhardt, Greg A.; Marmarelis, Vasilis Z.; Berger, Theodore W.; Deadwyler, Sam A.

2014-01-01

Objective Memory accuracy is a major problem in human disease and is the primary factor that defines Alzheimer’s’, aging and dementia resulting from impaired hippocampal function in medial temporal lobe. Development of a hippocampal memory neuroprosthesis that facilitates normal memory encoding in nonhuman primates (NHPs) could provide the basis for improving memory in human disease states. Approach NHPs trained to perform a short-term delayed match to sample (DMS) memory task were examined with multi-neuron recordings from synaptically connected hippocampal cell fields, CA1 and CA3. Recordings were analyzed utilizing a previously developed nonlinear multi-input multi-output (MIMO) neuroprosthetic model, capable of extracting CA3-to-CA1 spatiotemporal firing patterns during DMS performance. Main Results The MIMO model verified that specific CA3-to-CA1 firing patterns were critical for successful encoding of Sample phase information on more difficult DMS trials. This was validated by delivery of successful MIMO-derived encoding patterns via electrical stimulation to the same CA1 recording locations during the Sample phase which facilitated task performance in the subsequent delayed Match phase on difficult trials that required more precise encoding of Sample information. Significance These findings provide the first successful application of a neuroprosthesis designed to enhance and/or repair memory encoding in primate brain. PMID:24216292

Computer-based evaluation of Alzheimer's disease and mild cognitive impairment patients during a picture description task.

PubMed

Hernández-Domínguez, Laura; Ratté, Sylvie; Sierra-Martínez, Gerardo; Roche-Bergua, Andrés

2018-01-01

We present a methodology to automatically evaluate the performance of patients during picture description tasks. Transcriptions and audio recordings of the Cookie Theft picture description task were used. With 25 healthy elderly control (HC) samples and an information coverage measure, we automatically generated a population-specific referent. We then assessed 517 transcriptions (257 Alzheimer's disease [AD], 217 HC, and 43 mild cognitively impaired samples) according to their informativeness and pertinence against this referent. We extracted linguistic and phonetic metrics which previous literature correlated to early-stage AD. We trained two learners to distinguish HCs from cognitively impaired individuals. Our measures significantly ( P  < .001) correlated with the severity of the cognitive impairment and the Mini-Mental State Examination score. The classification sensitivity was 81% (area under the curve of receiver operating characteristics = 0.79) and 85% (area under the curve of receiver operating characteristics = 0.76) between HCs and AD and between HCs and AD and mild cognitively impaired, respectively. An automated assessment of a picture description task could assist clinicians in the detection of early signs of cognitive impairment and AD.

Electrophysiological evidence for women superiority on unfamiliar face processing.

PubMed

Sun, Tianyi; Li, Lin; Xu, Yuanli; Zheng, Li; Zhang, Weidong; Zhou, Fanzhi Anita; Guo, Xiuyan

2017-02-01

Previous research has reported that women superiority on face recognition tasks, taking sex difference in accuracy rates as major evidence. By appropriately modifying experimental tasks and examining reaction time as behavioral measure, it was possible to explore which stage of face processing contributes to womens' superiority. We used a modified delayed matching-to-sample task to investigate the time course characteristics of face recognition by ERP, for both men and women. In each trial, participants matched successively presented faces to samples (target faces) by key pressing. It was revealed that women were more accurate and faster than men on the task. ERP results showed that compared to men, women had shorter peak latencies of early components P100 and N170, as well as larger mean amplitude of the late positive component P300. Correlations between P300 mean amplitudes and RTs were found for both sexes. Besides, reaction times of women but not men were positively correlated with N170 latencies. In general, we provided further evidence for women superiority on face recognition in both behavioral and neural aspects. Copyright © 2016 Elsevier Ireland Ltd and Japan Neuroscience Society. All rights reserved.

Theta power is reduced in healthy cognitive aging.

PubMed

Cummins, Tarrant D R; Finnigan, Simon

2007-10-01

The effects of healthy cognitive aging on electroencephalographic (EEG) theta (4.9-6.8 Hz) power were examined during performance of a modified Sternberg, S., 1966. High-speed scanning in human memory. Science 153, 652-654.) word recognition task. In a sample of fourteen young (mean age 21.9 years, range=18-27) and fourteen older (mean age 68.4 years, range=60-80) participants, theta power was found to be significantly lower in older adults during both the retention and recognition intervals. This theta power difference was greatest at the fronto-central midline electrode and occurred in parallel with a small, non-significant decrease in recognition accuracy in the older sample. A significant decrease in older adults' mean theta power was also observed in resting EEG, however, it was of substantially smaller magnitude than the task-related theta difference. It is proposed that a neurophysiological measure(s), such as task-specific frontal midline theta (fmtheta) power, may be a more sensitive marker of cognitive aging than task performance measures. Furthermore, as recent research indicates that fmtheta is generated primarily in the anterior cingulate cortex, the current findings support evidence that the function of brain networks incorporating this structure may be affected in cognitive aging.

Characterizing quantum supremacy in near-term devices

NASA Astrophysics Data System (ADS)

Boixo, Sergio; Isakov, Sergei V.; Smelyanskiy, Vadim N.; Babbush, Ryan; Ding, Nan; Jiang, Zhang; Bremner, Michael J.; Martinis, John M.; Neven, Hartmut

2018-06-01

A critical question for quantum computing in the near future is whether quantum devices without error correction can perform a well-defined computational task beyond the capabilities of supercomputers. Such a demonstration of what is referred to as quantum supremacy requires a reliable evaluation of the resources required to solve tasks with classical approaches. Here, we propose the task of sampling from the output distribution of random quantum circuits as a demonstration of quantum supremacy. We extend previous results in computational complexity to argue that this sampling task must take exponential time in a classical computer. We introduce cross-entropy benchmarking to obtain the experimental fidelity of complex multiqubit dynamics. This can be estimated and extrapolated to give a success metric for a quantum supremacy demonstration. We study the computational cost of relevant classical algorithms and conclude that quantum supremacy can be achieved with circuits in a two-dimensional lattice of 7 × 7 qubits and around 40 clock cycles. This requires an error rate of around 0.5% for two-qubit gates (0.05% for one-qubit gates), and it would demonstrate the basic building blocks for a fault-tolerant quantum computer.

Meta-analytic investigations of structural grey matter, executive domain-related functional activations, and white matter diffusivity in obsessive compulsive disorder: an integrative review.

PubMed

Eng, Goi Khia; Sim, Kang; Chen, Shen-Hsing Annabel

2015-05-01

Obsessive-compulsive disorder (OCD) is a debilitating disorder. However, existing neuroimaging findings involving executive function and structural abnormalities in OCD have been mixed. Here we conducted meta-analyses to investigate differences in OCD samples and controls in: Study 1 - grey matter structure; Study 2 - executive function task-related activations during (i) response inhibition, (ii) interference, and (iii) switching tasks; and Study 3 - white matter diffusivity. Results showed grey matter differences in the frontal, striatal, thalamus, parietal and cerebellar regions; task domain-specific neural differences in similar regions; and abnormal diffusivity in major white matter regions in OCD samples compared to controls. Our results reported concurrence of abnormal white matter diffusivity with corresponding abnormalities in grey matter and task-related functional activations. Our findings suggested the involvement of other brain regions not included in the cortico-striato-thalamo-cortical network, such as the cerebellum and parietal cortex, and questioned the involvement of the orbitofrontal region in OCD pathophysiology. Future research is needed to clarify the roles of these brain regions in the disorder. Copyright © 2015 Elsevier Ltd. All rights reserved.

Cognitive Sex Differences in Reasoning Tasks: Evidence from Brazilian Samples of Educational Settings

ERIC Educational Resources Information Center

Flores-Mendoza, Carmen; Widaman, Keith F.; Rindermann, Heiner; Primi, Ricardo; Mansur-Alves, Marcela; Pena, Carla Couto

2013-01-01

Sex differences on the Attention Test (AC), the Raven's Standard Progressive Matrices (SPM), and the Brazilian Cognitive Battery (BPR5), were investigated using four large samples (total N=6780), residing in the states of Minas Gerais and Sao Paulo. The majority of samples used, which were obtained from educational settings, could be considered a…

The prestimulus default mode network state predicts cognitive task performance levels on a mental rotation task.

PubMed

Kamp, Tabea; Sorger, Bettina; Benjamins, Caroline; Hausfeld, Lars; Goebel, Rainer

2018-06-22

Linking individual task performance to preceding, regional brain activation is an ongoing goal of neuroscientific research. Recently, it could be shown that the activation and connectivity within large-scale brain networks prior to task onset influence performance levels. More specifically, prestimulus default mode network (DMN) effects have been linked to performance levels in sensory near-threshold tasks, as well as cognitive tasks. However, it still remains uncertain how the DMN state preceding cognitive tasks affects performance levels when the period between task trials is long and flexible, allowing participants to engage in different cognitive states. We here investigated whether the prestimulus activation and within-network connectivity of the DMN are predictive of the correctness and speed of task performance levels on a cognitive (match-to-sample) mental rotation task, employing a sparse event-related functional magnetic resonance imaging (fMRI) design. We found that prestimulus activation in the DMN predicted the speed of correct trials, with a higher amplitude preceding correct fast response trials compared to correct slow response trials. Moreover, we found higher connectivity within the DMN before incorrect trials compared to correct trials. These results indicate that pre-existing activation and connectivity states within the DMN influence task performance on cognitive tasks, both effecting the correctness and speed of task execution. The findings support existing theories and empirical work on relating mind-wandering and cognitive task performance to the DMN and expand these by establishing a relationship between the prestimulus DMN state and the speed of cognitive task performance. © 2018 The Authors. Brain and Behavior published by Wiley Periodicals, Inc.

The Lexical Stroop Sort (LSS) picture-word task: a computerized task for assessing the relationship between language and executive functioning in school-aged children.

PubMed

Wilbourn, Makeba Parramore; Kurtz, Laura E; Kalia, Vrinda

2012-03-01

The relationship between language development and executive function (EF) in children is not well understood. The Lexical Stroop Sort (LSS) task is a computerized EF task created for the purpose of examining the relationship between school-aged children's oral language development and EF. To validate this new measure, a diverse sample of school-aged children completed standardized oral language assessments, the LSS task, and the widely used Dimensional Change Card Sort (DCCS; Zelazo, 2006) task. Both EF tasks require children to sort stimuli into categories based on predetermined rules. While the DCCS largely relies on visual stimuli, the LSS employs children's phonological loop to access their semantic knowledge base. Accuracy and reaction times were recorded for both tasks. Children's scores on the LSS task were correlated with their scores on the DCCS task, and a similar pattern of relationships emerged between children's vocabulary and the two EF tasks, thus providing convergent validity for the LSS. However, children's phonological awareness was associated with their scores on the LSS, but not with those on the DCCS. In addition, a mediation model was used to elucidate the predictive relationship between phonological awareness and children's performance on the LSS task, with children's vocabulary fully mediating this relationship. The use of this newly created and validated LSS task with different populations, such as preschoolers and bilinguals, is also discussed.

The effect of pain on task switching: pain reduces accuracy and increases reaction times across multiple switching paradigms.

PubMed

Attridge, Nina; Keogh, Edmund; Eccleston, Christopher

2016-10-01

Pain disrupts attention, which may have negative consequences for daily life for people with acute or chronic pain. It has been suggested that switching between tasks may leave us particularly susceptible to pain-related attentional disruption, because we need to disengage our attention from one task before shifting it onto another. Switching tasks typically elicit lower accuracies and/or longer reaction times when participants switch to a new task compared with repeating the same task, and pain may exacerbate this effect. We present 3 studies to test this hypothesis. In study 1, participants completed 2 versions of an alternating runs switching task under pain-free and thermal pain-induction conditions. Pain did not affect performance on either task. In studies 2 and 3, we examined 7 versions of the switching task using large general population samples, experiencing a variety of naturally occurring pain conditions, recruited and tested on the internet. On all tasks, participants with pain had longer reaction times on both switch and repeat trials compared with participants without pain, but pain did not increase switch costs. In studies 2 and 3, we also investigated the effects of type of pain, duration of pain, and analgesics on task performance. We conclude that pain has a small dampening effect on performance overall on switching tasks. This suggests that pain interrupts attention even when participants are engaged in a trial, not only when attention has been disengaged for shifting to a new task set.

Hippocampus is required for paired associate memory with neither delay nor trial uniqueness

PubMed Central

Yoon, Jinah; Seo, Yeran; Kim, Jangjin; Lee, Inah

2012-01-01

Cued retrieval of memory is typically examined with delay when testing hippocampal functions, as in delayed matching-to-sample tasks. Equally emphasized in the literature, on the other hand, is the hippocampal involvement in making arbitrary associations. Paired associate memory tasks are widely used for examining this function. However, the two variables (i.e., delay and paired association) were often mixed in paired associate tasks, and this makes it difficult to localize the cognitive source of deficits with hippocampal perturbation. Specifically, a few studies have recently shown that rats can learn arbitrary paired associations between certain locations and nonspatial items (e.g., object or flavor) and later can retrieve the paired location when cued by the item remotely. Such tasks involve both (1) delay between sampling the cue and retrieving the target location and (2) arbitrary association between the cueing object and its paired location. Here, we tested whether delay was necessary in a cued paired associate task by using a task in which no delay existed between object cueing and the choice of its paired associate. Moreover, fixed associative relationships between the cueing objects and their paired locations were repeatedly used, thus involving no trial-unique association. Nevertheless, inactivations of the dorsal hippocampus with muscimol severely disrupted retrieval of paired associates, whereas the same manipulations did not affect discriminating individual objects or locations. The results powerfully demonstrate that the hippocampus is inherently required for retrieving paired associations between objects and places, and that delay and trial uniqueness of the paired associates are not necessarily required. PMID:22174309

Auditory working memory impairments in individuals at familial high risk for schizophrenia

PubMed Central

Seidman, Larry J.; Meyer, Eric C.; Giuliano, Anthony J.; Breiter, Hans C.; Goldstein, Jill M.; Kremen, William S.; Thermenos, Heidi W.; Toomey, Rosemary; Stone, William S.; Tsuang, Ming T.; Faraone, Stephen V.

2012-01-01

Objectives The search for predictors of schizophrenia has accelerated with a growing focus on early intervention and prevention of psychotic illness. Studying nonpsychotic relatives of individuals with schizophrenia enables identification of markers of vulnerability for the illness independent of confounds associated with psychosis. The goal of these studies was to develop new auditory continuous performance tests (ACPTs) and evaluate their effects in individuals with schizophrenia and their relatives. Methods We carried out two studies of auditory vigilance with tasks involving working memory (WM) and interference control with increasing levels of cognitive load to discern the information processing vulnerabilities in a sample of schizophrenia patients, and two samples of nonpsychotic relatives of individuals with schizophrenia and controls. Study 1 assessed adults (mean age = 41), and Study 2 assessed teenagers and young adults age 13-25 (mean =19). Results Patients with schizophrenia were impaired on all five versions of the ACPTs, while relatives were impaired only on WM tasks, particularly the two interference tasks that maximize cognitive load. Across all groups, the interference tasks were more difficult to perform than the other tasks. Schizophrenia patients performed worse than relatives who performed worse than controls. For patients, the effect sizes were large (Cohen’s d =1.5), whereas for relatives, they were moderate (d = ~0.40-0.50). There was no age by group interaction in the relatives –control comparison except for participants <31 years of age. Conclusions Novel WM tasks that manipulate cognitive load and interference control index an important component of the vulnerability to schizophrenia. PMID:22563872

A model for integrating elementary neural functions into delayed-response behavior.

PubMed

Gisiger, Thomas; Kerszberg, Michel

2006-04-01

It is well established that various cortical regions can implement a wide array of neural processes, yet the mechanisms which integrate these processes into behavior-producing, brain-scale activity remain elusive. We propose that an important role in this respect might be played by executive structures controlling the traffic of information between the cortical regions involved. To illustrate this hypothesis, we present a neural network model comprising a set of interconnected structures harboring stimulus-related activity (visual representation, working memory, and planning), and a group of executive units with task-related activity patterns that manage the information flowing between them. The resulting dynamics allows the network to perform the dual task of either retaining an image during a delay (delayed-matching to sample task), or recalling from this image another one that has been associated with it during training (delayed-pair association task). The model reproduces behavioral and electrophysiological data gathered on the inferior temporal and prefrontal cortices of primates performing these same tasks. It also makes predictions on how neural activity coding for the recall of the image associated with the sample emerges and becomes prospective during the training phase. The network dynamics proves to be very stable against perturbations, and it exhibits signs of scale-invariant organization and cooperativity. The present network represents a possible neural implementation for active, top-down, prospective memory retrieval in primates. The model suggests that brain activity leading to performance of cognitive tasks might be organized in modular fashion, simple neural functions becoming integrated into more complex behavior by executive structures harbored in prefrontal cortex and/or basal ganglia.

Neuropsychological function and suicidal behavior: attention control, memory and executive dysfunction in suicide attempt.

PubMed

Keilp, J G; Gorlyn, M; Russell, M; Oquendo, M A; Burke, A K; Harkavy-Friedman, J; Mann, J J

2013-03-01

Executive dysfunction, distinct from other cognitive deficits in depression, has been associated with suicidal behavior. However, this dysfunction is not found consistently across samples. Medication-free subjects with DSM-IV major depressive episode (major depressive disorder and bipolar type I disorder) and a past history of suicidal behavior (n = 72) were compared to medication-free depressed subjects with no history of suicidal behavior (n = 80) and healthy volunteers (n = 56) on a battery of tests assessing neuropsychological functions typically affected by depression (motor and psychomotor speed, attention, memory) and executive functions reportedly impaired in suicide attempters (abstract/contingent learning, working memory, language fluency, impulse control). All of the depressed subjects performed worse than healthy volunteers on motor, psychomotor and language fluency tasks. Past suicide attempters, in turn, performed worse than depressed non-attempters on attention and memory/working memory tasks [a computerized Stroop task, the Buschke Selective Reminding Task (SRT), the Benton Visual Retention Test (VRT) and an N-back task] but not on other executive function measures, including a task associated with ventral prefrontal function (Object Alternation). Deficits were not accounted for by current suicidal ideation or the lethality of past attempts. A small subsample of those using a violent method in their most lethal attempt showed a pattern of poor executive performance. Deficits in specific components of attention control, memory and working memory were associated with suicidal behavior in a sample where non-violent attempt predominated. Broader executive dysfunction in depression may be associated with specific forms of suicidal behavior, rather than suicidal behavior per se.

Clinical Correlates of Carbon Dioxide Hypersensitivity in Children.

PubMed

Rappaport, Lance M; Sheerin, Christina; Carney, Dever M; Towbin, Kenneth E; Leibenluft, Ellen; Pine, Daniel S; Brotman, Melissa A; Roberson-Nay, Roxann; Hettema, John M

2017-12-01

Hypersensitivity to carbon dioxide (CO 2 )-enriched air may be a promising risk marker for anxiety disorders. Among adult and adolescent samples, heterogeneity in distress response to the CO 2 challenge task indexes 3 underlying classes of individuals, which distinguish between sustained and acute threat response as markers for internalizing disorders, broadly, and anxiety disorders, specifically. The present study examines latent classes in children's response to the CO 2 challenge task to clarify the association of CO 2 hypersensitivity with anxiety and internalizing symptomatology in childhood. Healthy children from a community twin sample (N = 538; age 9-13 years) rated anxious distress every 2 minutes while breathing air enriched to 7.5% CO 2 for 8 minutes. Latent growth mixture modeling evaluated potential classes of individuals with characteristic trajectories of distress during the task to clarify the association with internalizing disorder symptoms and related traits (e.g., anxiety sensitivity, irritability). Although all participants reported increased distress during the task, interindividual heterogeneity in distress indexed 3 underlying classes: a consistently low class ("low"), a consistently high class ("high"), and participants who demonstrated markedly increased acute distress ("acute"). Compared to the low class, the high class reported greater internalizing psychopathology, whereas membership in the acute class was associated with experiencing a panic-like event during the task. As in older individuals, 3 distinct trajectories emerged to capture interindividual heterogeneity in children's distress during the CO 2 challenge task. These classes were distinguished by clinical validators that reinforce the association of CO 2 hypersensitivity and internalizing disorder phenotypes in children. Copyright © 2017 American Academy of Child and Adolescent Psychiatry. All rights reserved.

Assessment of Occupational Exposure to Bisphenol A in Five Different Production Companies in Finland.

PubMed

Heinälä, Milla; Ylinen, Katriina; Tuomi, Tapani; Santonen, Tiina; Porras, Simo P

2017-01-01

The aim of the study was to assess occupational exposure to bisphenol A in Finland. Five companies took part in the research project: two paint factories (liquid and powder paints), a composite product factory, a thermal paper factory, and a tractor factory. Exposure was assessed by measuring total bisphenol A excretion (free and conjugated) from urine samples, and its concentrations in the air. The results revealed the specific work tasks in two of five companies in which significant occupational exposure to bisphenol A may occur. In the manufacturing of liquid paint hardener, urine samples collected after the working day showed bisphenol A levels of up to 100-170 µg l-1. Workers in thermal paper manufacturing were also exposed to bisphenol A, especially those working in the manufacture of coating material and operating coating machines. Median concentrations of the post-shift urine samples of coating machine workers were in the range of 130-250 µg l-1. The highest bisphenol A concentrations were in the range of 1000-1500 µg l-1. Recommendations for more effective personal protection resulted in decreased exposure, particularly among coating machine operators. In the rest of the companies, urinary bisphenol A levels were typically in the range of those of the general population. Bisphenol A concentrations in air samples were typically low (<40 µg m-3), except in some short-term duties related to the handling of solid bisphenol A (maximum 17.6 mg m-3). Low air levels, even in the companies with high urinary levels, suggest exposure via dermal contact. According to the results, exposure to bisphenol A may occur particularly in work tasks that involve the use of pure bisphenol A. In these tasks, special attention should be paid to the prevention of skin exposure. Inhalation exposure may become relevant in dusty work tasks. Since skin exposure is of potential concern in these tasks, biomonitoring is recommended as the method for assessing occupational exposure to bisphenol A. © The Author 2017. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

Customized laboratory information management system for a clinical and research leukemia cytogenetics laboratory.

PubMed

Bakshi, Sonal R; Shukla, Shilin N; Shah, Pankaj M

2009-01-01

We developed a Microsoft Access-based laboratory management system to facilitate database management of leukemia patients referred for cytogenetic tests in regards to karyotyping and fluorescence in situ hybridization (FISH). The database is custom-made for entry of patient data, clinical details, sample details, cytogenetics test results, and data mining for various ongoing research areas. A number of clinical research laboratoryrelated tasks are carried out faster using specific "queries." The tasks include tracking clinical progression of a particular patient for multiple visits, treatment response, morphological and cytogenetics response, survival time, automatic grouping of patient inclusion criteria in a research project, tracking various processing steps of samples, turn-around time, and revenue generated. Since 2005 we have collected of over 5,000 samples. The database is easily updated and is being adapted for various data maintenance and mining needs.

Physiological and psychological effects of delivering medical news using a simulated physician-patient scenario.

PubMed

Cohen, Lorenzo; Baile, Walter F; Henninger, Evelyn; Agarwal, Sandeep K; Kudelka, Andrzej P; Lenzi, Renato; Sterner, Janet; Marshall, Gailen D

2003-10-01

We examined the acute stress response associated with having to deliver either bad or good medical news using a simulated physician-patient scenario. Twenty-five healthy medical students were randomly assigned to a bad medical news (BN), a good medical news (GN), or a control group that read magazines during the session. Self-report measures were obtained before and after the task. Blood pressure and heart rate were measured throughout the task period. Four blood samples were obtained across the task period. The BN and GN tasks produced significant increases in self-reported distress and cardiovascular responses compared with the control group. There was also a significant increase in natural killer cell function 10 min into the task in the BN group compared with the control group. The BN task was also somewhat more stressful than the GN task, as shown by the self-report and cardiovascular data. These findings suggest that a simulated physician-patient scenario produces an acute stress response in the "physician," with the delivery of bad medical news more stressful than the delivery of good medical news.

Implicit learning and emotional responses in nine-month-old infants.

PubMed

Angulo-Barroso, Rosa M; Peciña, Susana; Lin, Xu; Li, Mingyan; Sturza, Julia; Shao, Jie; Lozoff, Betsy

2017-08-01

To study the interplay between motor learning and emotional responses of young infants, we developed a contingent learning paradigm that included two related, difficult, operant tasks. We also coded facial expression to characterise emotional response to learning. In a sample of nine-month-old healthy Chinese infants, 44.7% achieved learning threshold during this challenging arm-conditioning test. Some evidence of learning was observed at the beginning of the second task. The lowest period of negative emotions coincided with the period of maximum movement responses after the initiation of the second task, and movement responses negatively correlated with the frequency of negative emotions. Positive emotions, while generally low throughout the task, increased during peak performance especially for learners. Peak frequency of movement responses was positively correlated with the frequency of positive emotions. Despite the weak evidence of learning this difficult task, our results from the learners would suggest that increasing positive emotions, and perhaps down-regulating negative emotional responses, may be important for improving performance and learning a complex operant task in infancy. Further studies are necessary to determine the role of emotions in learning difficult tasks in infancy.

Effects of emotionally valenced working memory taxation on negative memories.

PubMed

Tsai, Cynthia; McNally, Richard J

2014-03-01

Memories enter a labile state during recollection. Thus, memory changes that occur during recollection can affect future instances of its activation. Having subjects perform a secondary task that taxes working memory while they recall a negative emotional memory often reduces its vividness and emotional intensity during subsequent recollections. However, researchers have not manipulated the emotional valence of the secondary task itself. Subjects viewed a video depicting the aftermath of three fatal road traffic accidents, establishing the same negative emotional memory for all subjects. We then tested their memory for the video after randomly assigning them to no secondary task or a delayed match-to-sample secondary task involving photographs of positive, negative, or neutral emotional valence. The positive secondary task reduced memory for details about the video, whereas negative and neutral tasks did not. We did not assess the vividness and emotionality of the subjects' memory of the video. Having subjects recall a stressful experience while performing a positively valent secondary task can decrement details of the memory and perhaps its emotionality. Copyright © 2013 Elsevier Ltd. All rights reserved.

Procedural Learning and Individual Differences in Language

PubMed Central

Lee, Joanna C.; Tomblin, J. Bruce

2014-01-01

The aim of the current study was to examine different aspects of procedural memory in young adults who varied with regard to their language abilities. We selected a sample of procedural memory tasks, each of which represented a unique type of procedural learning, and has been linked, at least partially, to the functionality of the corticostriatal system. The findings showed that variance in language abilities is associated with performance on different domains of procedural memory, including the motor domain (as shown in the pursuit rotor task), the cognitive domain (as shown in the weather prediction task), and the linguistic domain (as shown in the nonword repetition priming task). These results implicate the corticostriatal system in individual differences in language. PMID:26190949

The Influence of Math Anxiety, Math Performance, Worry, and Test Anxiety on the Iowa Gambling Task and Balloon Analogue Risk Task.

PubMed

Buelow, Melissa T; Barnhart, Wesley R

2017-01-01

Multiple studies have shown that performance on behavioral decision-making tasks, such as the Iowa Gambling Task (IGT) and Balloon Analogue Risk Task (BART), is influenced by external factors, such as mood. However, the research regarding the influence of worry is mixed, and no research has examined the effect of math or test anxiety on these tasks. The present study investigated the effects of anxiety (including math anxiety) and math performance on the IGT and BART in a sample of 137 undergraduate students. Math performance and worry were not correlated with performance on the IGT, and no variables were correlated with BART performance. Linear regressions indicated math anxiety, physiological anxiety, social concerns/stress, and test anxiety significantly predicted disadvantageous selections on the IGT during the transition from decision making under ambiguity to decision making under risk. Implications for clinical evaluation of decision making are discussed. © The Author(s) 2015.

It's about time: revisiting temporal processing deficits in dyslexia.

PubMed

Casini, Laurence; Pech-Georgel, Catherine; Ziegler, Johannes C

2018-03-01

Temporal processing in French children with dyslexia was evaluated in three tasks: a word identification task requiring implicit temporal processing, and two explicit temporal bisection tasks, one in the auditory and one in the visual modality. Normally developing children matched on chronological age and reading level served as a control group. Children with dyslexia exhibited robust deficits in temporal tasks whether they were explicit or implicit and whether they involved the auditory or the visual modality. First, they presented larger perceptual variability when performing temporal tasks, whereas they showed no such difficulties when performing the same task on a non-temporal dimension (intensity). This dissociation suggests that their difficulties were specific to temporal processing and could not be attributed to lapses of attention, reduced alertness, faulty anchoring, or overall noisy processing. In the framework of cognitive models of time perception, these data point to a dysfunction of the 'internal clock' of dyslexic children. These results are broadly compatible with the recent temporal sampling theory of dyslexia. © 2017 John Wiley & Sons Ltd.

Think manager--think male in adolescents and its relation to sexism and emotions in leadership.

PubMed

García-Ael, Cristina; Cuadrado, Isabel; Molero, Fernando

2013-01-01

From the perspective of the Think manager--think male, this study was conducted to examine the type of leadership role depending on gender in a sample of 158 Spanish adolescents -according to three types of leaders: "male middle leader", "female middle leader" and "middle leader in general". The kind of emotional expression (positive and negative) evoked by their leadership behaviors (task- and relationship- oriented) was also analyzed. Lastly, whether adolescents' sexist beliefs affected the attribution of traits and the emotional expression towards these leaders was examined. Results showed that task-oriented traits were more characteristic of the leadership role than relationship-oriented traits. Adolescents expressed more positive emotions towards a task-oriented leader and towards a leader behaving in ways associated with both task- and relationship- oriented styles, but only for men. Finally, hostile sexism predicted fewer task-oriented traits to female leaders, more negative affect towards task-oriented male leaders and towards counter-stereotypic leaders. These results were moderated by the sex of adolescents.

Acute effects of caffeine on several operant behaviors in rhesus monkeys.

PubMed

Buffalo, E A; Gillam, M P; Allen, R R; Paule, M G

1993-11-01

The acute effects of 1,3-trimethylxanthine (caffeine) were assessed using an operant test battery (OTB) of complex food-reinforced tasks that are thought to depend upon relatively specific brain functions, such as motivation to work for food (progressive ratio, PR), learning (incremental repeated acquisition, IRA), color and position discrimination (conditioned position responding, CPR), time estimation (temporal response differentiation, TRD), and short-term memory and attention (delayed matching-to-sample, DMTS). Endpoints included response rates (RR), accuracies (ACC), and percent task completed (PTC). Caffeine sulfate (0.175-20.0 mg/kg, IV), given 15 min pretesting, produced significant dose-dependent decreases in TRD percent task completed and accuracy at doses > or = 5.6 mg/kg. Caffeine produced no systematic effects on either DMTS or PR responding, but low doses tended to enhance performance in both IRA and CPR tasks. Thus, in monkeys, performance of an operant task designed to model time estimation is more sensitive to the disruptive effects of caffeine than is performance of the other tasks in the OTB.

Developmental changes and gender effects on motivational constructs based on the expectancy-value model in Czech and United States students regarding learning of science, mathematics, and other subjects

NASA Astrophysics Data System (ADS)

Yang, Eun-Mi

This study employed American and Czech student samples to investigate the motivational constructs used in Eccles and Wigfield's (1983) expectancy-value model. To predict achievement behavior, the model specifies relationships among expectancy for-success and task value, task-specific self-concept, perception of task-difficulty, perceptions of social environment, and interpretations and attributions for past events in relation to the social world. Czech and American students (n = 1,145) in grades 4--12 were the participants in this study. The causal relationships among the constructs were tested to investigate structural similarities and differences in the models for both countries. This study also explored developmental changes, gender, and national differences in the students' motivational beliefs for these motivational constructs: Expectancy for Success, Intrinsic Interest Value, Task-specific Self-concept, Perception of Task-difficulty, and Perceived Vocational Gender Dominance for science, mathematics, and other school subjects. The findings indicated that, for both countries, with respect to changes over grade level, compared to the younger students, the older students showed lower motivational beliefs for most subject areas except reading. However, the Czech students in grades 6--8 showed more positive motivational beliefs in life science and social studies than did the Czech students in other grade levels. In comparing genders, the male students exhibited more positive motivational beliefs in physical science than did the female students, and female students showed more positive motivational beliefs in reading than did the male students. For life science, the Czech female students rated Intrinsic Interest Value and Task-specific Self-concept higher than did their peer male students. The American students' motivational beliefs in reading were more positive than were Czech students', and the Czech students held more positive motivational beliefs in life science than did the American students. With minor variations for each country, the expectancy-value model provided a reasonable tool for understanding the causal relationships among the motivational beliefs. For the Czech sample, Perception of Task-difficulty was a strong negative predictor for Expectancy for Success for most school subjects except life science whereas, for the American sample, it was a weak but significant negative predictor for Intrinsic Interest Value for most school subjects except social studies. Implications for science education are discussed.

Event Processing and Variable Part of Sample Period Determining in Combined Systems Using GA

NASA Astrophysics Data System (ADS)

Strémy, Maximilián; Závacký, Pavol; Jedlička, Martin

2011-01-01

This article deals with combined dynamic systems and usage of modern techniques in dealing with these systems, focusing particularly on sampling period design, cyclic processing tasks and related processing algorithms in the combined event management systems using genetic algorithms.

Development of an automated pre-sampling plan for construction projects : final report.

DOT National Transportation Integrated Search

1983-03-01

The development of an automated pre-sampling plan was undertaken to free the district construction personnel from the cumbersome and time-consuming task of preparing such plans manually. A computer program was written and linked to a data file which ...

RECOVERY OF HELICOBACTER PYLORI FROM WATER BY IMMUNOMAGNETIC CAPTURE

EPA Science Inventory

A few reports have been written stating that H. pylori can be found in waters. However, detection and identification of H. pylori from water samples remains a very difficult task. One method that seems to work successfully is immunomagnetic capture. Water samples were concentr...

Algorithm-Dependent Generalization Bounds for Multi-Task Learning.

PubMed

Liu, Tongliang; Tao, Dacheng; Song, Mingli; Maybank, Stephen J

2017-02-01

Often, tasks are collected for multi-task learning (MTL) because they share similar feature structures. Based on this observation, in this paper, we present novel algorithm-dependent generalization bounds for MTL by exploiting the notion of algorithmic stability. We focus on the performance of one particular task and the average performance over multiple tasks by analyzing the generalization ability of a common parameter that is shared in MTL. When focusing on one particular task, with the help of a mild assumption on the feature structures, we interpret the function of the other tasks as a regularizer that produces a specific inductive bias. The algorithm for learning the common parameter, as well as the predictor, is thereby uniformly stable with respect to the domain of the particular task and has a generalization bound with a fast convergence rate of order O(1/n), where n is the sample size of the particular task. When focusing on the average performance over multiple tasks, we prove that a similar inductive bias exists under certain conditions on the feature structures. Thus, the corresponding algorithm for learning the common parameter is also uniformly stable with respect to the domains of the multiple tasks, and its generalization bound is of the order O(1/T), where T is the number of tasks. These theoretical analyses naturally show that the similarity of feature structures in MTL will lead to specific regularizations for predicting, which enables the learning algorithms to generalize fast and correctly from a few examples.

A comparison of basic and social cognition between schizophrenia and schizoaffective disorder.

PubMed

Fiszdon, Joanna M; Richardson, Randall; Greig, Tamasine; Bell, Morris D

2007-03-01

We compared basic and social cognition in individuals with schizophrenia and schizoaffective disorder. 199 individuals with schizophrenia and 73 with schizoaffective disorder were compared on measures of executive function, verbal and nonverbal memory, and processing speed, as well as two measures of social cognition, the Hinting Task and the Bell Lysaker Emotion Recognition Task. The samples did not differ significantly on the basic cognitive measures, however individuals with schizoaffective disorder performed significantly better than those with schizophrenia on the Hinting Task, a measure of Theory of Mind. Results provide limited support for a taxonomic distinction between the two disorders.

FY-12 INL KR CAPTURE ACTIVITIES SUPPORTING THE OFF-GAS SIGMA TEAM

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

Troy G. Garn; Mitchell R. Greenhalgh; Jack D Law

2012-08-01

Tasks performed this year by INL Kr capture off-gas team members can be segregated into three separate task sub-sections which include: 1) The development and testing of a new engineered form sorbent, 2) An initial NDA gamma scan effort performed on the drum containing the Legacy Kr-85 sample materials, and 3) Collaborative research efforts with PNNL involving the testing of the Ni-DOBDC MOF and an initial attempt to make powdered chalcogel material into an engineered form using our binding process. This document describes the routes to success for the three task sub-sections.

Dust, endotoxin, fungi, and bacteria exposure as determined by work task, season, and type of plant in a flower greenhouse.

PubMed

Thilsing, Trine; Madsen, Anne Mette; Basinas, Ioannis; Schlünssen, Vivi; Tendal, Kira; Bælum, Jesper

2015-03-01

Greenhouse workers are exposed to dust, endotoxin, fungi, and bacteria potentially causing airway inflammation as well as systemic symptoms. Knowledge about determinants of exposure is a prerequisite for efficient prevention through knowledge-based reduction in exposure. The objective of this study was to assess the occupational exposure in a flower greenhouse and to investigate the impact of work tasks on the intensity and variability in exposure. Seventy-six personal full-shift exposure measurements were performed on 38 employees in a Danish flower greenhouse producing Campanula, Lavandula, Rhipsalideae, and Helleborus. The samples were gravimetrically analysed for inhalable dust. Endotoxin was assessed by the Limulus Amoebocyte Lysate test and culture-based quantification of bacteria and fungi was performed. Information on the performed tasks during sampling was extracted from the greenhouse electronic task logging system. Associations between log-transformed exposure outcomes, season, and work tasks were examined in linear mixed-effects regression with worker identity as random effect. Measured concentrations ranged between 0.04 and 2.41mg m(-3) for inhalable dust and between 0.84 and 1097 EU m(-3) for endotoxin exposure, with the highest mean levels measured during Lavandula and Campanula handling, respectively. Personal exposure to fungi ranged between 1.8×10(2) and 3.4×10(6) colony-forming units (CFU) m(-3) and to bacteria between 1.6×10(1) and 4.2×10(5) CFU m(-3). Exposure to dust, endotoxin, fungi, and bacteria differed between seasons. Packing Lavandula, sticking, potting, and grading Rhipsalideae, and all examined tasks related to Campanula production except sticking increased dust exposure. Endotoxin exposure was increased during sticking Campanula and pinching or packing Rhipsalideae, and fungi exposure was elevated by subtasks performed in the research and development area for Campanula, and by potting, packing/dumping Campanula. Sticking and working with subtasks in the research and development area for Campanula increased bacteria exposure. This study revealed moderate dust exposure levels compared to the levels observed in other greenhouse productions and other occupations with organic dust exposure such as farming. However, high exposures to bacteria and fungi were detected during selected tasks and the proposed health-based endotoxin exposure limit of 90 EU m(-3) was exceeded in 30% of the samples, which may have health implications for the employees. Exposure levels were found to vary depending on the tasks performed, and thereby results can be used to direct task-based initiatives to reduce workplace exposures. © The Author 2014. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

Analysis of internal and external validity criteria for a computerized visual search task: A pilot study.

PubMed

Richard's, María M; Introzzi, Isabel; Zamora, Eliana; Vernucci, Santiago

2017-01-01

Inhibition is one of the main executive functions, because of its fundamental role in cognitive and social development. Given the importance of reliable and computerized measurements to assessment inhibitory performance, this research intends to analyze the internal and external criteria of validity of a computerized conjunction search task, to evaluate the role of perceptual inhibition. A sample of 41 children (21 females and 20 males), aged between 6 and 11 years old (M = 8.49, SD = 1.47), intentionally selected from a private management school of Mar del Plata (Argentina), middle socio-economic level were assessed. The Conjunction Search Task from the TAC Battery, Coding and Symbol Search tasks from Wechsler Intelligence Scale for Children were used. Overall, results allow us to confirm that the perceptual inhibition task form TAC presents solid rates of internal and external validity that make a valid measurement instrument of this process.

Effects of a cognitive modulator in the theta and alpha asymmetry during a typewriting task: a sensorimotor integration perspective.

PubMed

Cunha, Marlo; Machado, Sergio; Miana, Luiz Cláudio; Machado, Dionis; Bastos, Victor Hugo; Velasques, Bruna; Cagy, Maurício; Basile, Luis F; Piedade, Roberto; Ribeiro, Pedro

2009-06-01

This study aimed to elucidate cortical mechanisms and to identify the areas where occur such mechanisms due to interaction between bromazepam and motor learning. The sample was composed of 45 healthy subjects randomly distributed in 3 groups: placebo (n=15), bromazepam 3 mg (n=15) or bromazepam 6 mg (n=15). To perform the experimental task, subjects sat comfortably at a distance of approximately 20 cm from the typewriter. The typewriter keyboard was covered with a wooden box to avoid visual information about the hands' position. The typewriting task was performed concomitantly with EEG recording. ANOVA two-way results indicated a decreased asymmetry in sensorimotor areas in the experimental groups. Our interpretation is that moderate doses of bromazepam may improve performance on tasks with predictable elements to promote stability of psychomotor functions, but may also impair performance on tasks executed in unpredictable environments.

Dissociations and associations of performance in syntactic comprehension in aphasia and their implications for the nature of aphasic deficits.

PubMed

Caplan, David; Michaud, Jennifer; Hufford, Rebecca

2013-10-01

Sixty-one pwa were tested on syntactic comprehension in three tasks: sentence-picture matching, sentence-picture matching with auditory moving window presentation, and object manipulation. There were significant correlations of performances on sentences across tasks. First factors on which all sentence types loaded in unrotated factor analyses accounted for most of the variance in each task. Dissociations in performance between sentence types that differed minimally in their syntactic structures were not consistent across tasks. These results replicate previous results with smaller samples and provide important validation of basic aspects of aphasic performance in this area of language processing. They point to the role of a reduction in processing resources and of the interaction of task demands and parsing and interpretive abilities in the genesis of patient performance. Copyright © 2013 Elsevier Inc. All rights reserved.

The own-age face recognition bias is task dependent.

PubMed

Proietti, Valentina; Macchi Cassia, Viola; Mondloch, Catherine J

2015-08-01

The own-age bias (OAB) in face recognition (more accurate recognition of own-age than other-age faces) is robust among young adults but not older adults. We investigated the OAB under two different task conditions. In Experiment 1 young and older adults (who reported more recent experience with own than other-age faces) completed a match-to-sample task with young and older adult faces; only young adults showed an OAB. In Experiment 2 young and older adults completed an identity detection task in which we manipulated the identity strength of target and distracter identities by morphing each face with an average face in 20% steps. Accuracy increased with identity strength and facial age influenced older adults' (but not younger adults') strategy, but there was no evidence of an OAB. Collectively, these results suggest that the OAB depends on task demands and may be absent when searching for one identity. © 2014 The British Psychological Society.

Reading-Related Literacy Activities of American Adults: Time Spent, Task Types, and Cognitive Skills Used

ERIC Educational Resources Information Center

White, Sheida; Chen, Jing; Forsyth, Barbara

2010-01-01

This article presents data on the types and duration of reading-related activities reported by a volunteer sample of 400 adults (demographically similar to the U.S. adult population age 20 and older in terms of race, ethnicity, education, and working status) in the 2005 Real-World Tasks Study. This diary study revealed that adults spent, on…

Contribution of Temporal Processing Skills to Reading Comprehension in 8-Year-Olds: Evidence for a Mediation Effect of Phonological Awareness

ERIC Educational Resources Information Center

Malenfant, Nathalie; Grondin, Simon; Boivin, Michel; Forget-Dubois, Nadine; Robaey, Philippe; Dionne, Ginette

2012-01-01

This study tested whether the association between temporal processing (TP) and reading is mediated by phonological awareness (PA) in a normative sample of 615 eight-year-olds. TP was measured with auditory and bimodal (visual-auditory) temporal order judgment tasks and PA with a phoneme deletion task. PA partially mediated the association between…

Fabrication Development and Flow Testing of Underwater Superhydrophobic Films for Drag Reduction

DTIC Science & Technology

2017-03-21

form a large area Sidewall improved by using a chisel-edge blade 3/20/17 9 17/52 Task 3: Flow testing and characterization 18/52 Task 3.1 Develop shear...Before data collection for each run , the water tunnel was run at Re= 1.45x107 for a 3-5 minutes to de-wet SHPo sample, but improvement was not

The Model Human Processor and the Older Adult: Parameter Estimation and Validation within a Mobile Phone Task

ERIC Educational Resources Information Center

Jastrzembski, Tiffany S.; Charness, Neil

2007-01-01

The authors estimate weighted mean values for nine information processing parameters for older adults using the Card, Moran, and Newell (1983) Model Human Processor model. The authors validate a subset of these parameters by modeling two mobile phone tasks using two different phones and comparing model predictions to a sample of younger (N = 20;…

Teaching Everyday and School Related Tasks: Effective Instruction among Mexican-American Mothers. JSRI Working Paper No. 48.

ERIC Educational Resources Information Center

Moreno, Robert P.

A study examined the teaching behaviors of Mexican American mothers using an "everyday" and a "school-related" task. The sample consisted of 37 Mexican American mother-child dyads. All children were preschoolers, with a mean age of 6.1 years and no history of developmental delays or learning difficulties. All mothers were proficient in English and…

Working Memory Tasks in Relation to Phonological Processes of Arab Dyslexics in the State of Kuwait

ERIC Educational Resources Information Center

Al-dyiar, Mosaad Abo; Salem, Ashraf Atta M. S.

2013-01-01

The current study investigated the relationship between the working memory tasks and the phonological processes of Arab dyslexics in the primary stage in the State of Kuwait. The researchers used the descriptive research design. The sample of the study consists of 500 pupils (250 males and 250 females), their ages range from (9.05 ± 0.49) years…

Encapsulated Decon for Use on Medical Patients

DTIC Science & Technology

1983-12-01

Development of effective decon microcapsules was based on a series of tasks performed on this study. The preliminary tasks included a litera- ture search...culminated with evaluating selected microcapsules on pig skin samples, with HD, GB, arid GD. Results appear encouraging. The best capsule performance...term contact. in addition, a brief study showed magnetite can be incorporated into the capsule wall to provide magnetic microcapsules that can be

The Nation's Report Card: Writing 2011. National Assessment of Educational Progress at Grades 8 and 12. NCES 2012-470

ERIC Educational Resources Information Center

National Center for Education Statistics, 2012

2012-01-01

This report presents results of the 2011 National Assessment of Educational Progress (NAEP) in writing at grades 8 and 12. In this new national writing assessment sample, 24,100 eighth-graders and 28,100 twelfth-graders engaged with writing tasks and composed their responses on computer. The assessment tasks reflected writing situations common to…

An Assessment of the Influence of Attention to the Task in the Measurement of Visual Perceptual Abilities. Final Report.

ERIC Educational Resources Information Center

Rodenborn, Leo V., Jr.

The project's purpose was to determine whether attention to the task during testing was a confounding variable in measures of visual perception ability. Samples of 30 perceptually handicapped (PH) and 30 normal subjects (N) were randomly selected from children so classified on the Frostig DTVP, providing they had IQ scores between 85 and 115 on…

The Role of Executive Function in Arithmetic Problem-Solving Processes: A Study of Third Graders

ERIC Educational Resources Information Center

Viterbori, Paola; Traverso, Laura; Usai, M. Carmen

2017-01-01

This study investigated the roles of different executive function (EF) components (inhibition, shifting, and working memory) in 2-step arithmetic word problem solving. A sample of 139 children aged 8 years old and regularly attending the 3rd grade of primary school were tested on 6 EF tasks measuring different EF components, a reading task and a…

Fate of Mercury in Synthetic Gypsum Used for Wallboard Production

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

Jessica Marshall Sanderson

2006-06-01

This report presents and discusses results from Task 5 of the study ''Fate of Mercury in Synthetic Gypsum Used for Wallboard Production,'' performed at a full-scale commercial wallboard plant. Synthetic gypsum produced by wet flue gas desulfurization (FGD) systems on coal-fired power plants is commonly used in the manufacture of wallboard. The FGD process is used to control the sulfur dioxide emissions which would result in acid rain if not controlled. This practice has long benefited the environment by recycling the FGD gypsum byproduct, which is becoming available in increasing quantities, decreasing the need to landfill this material, and increasingmore » the sustainable design of the wallboard product. However, new concerns have arisen as recent mercury control strategies developed for power plants involve the capture of mercury in FGD systems. The objective of this study is to determine whether any mercury is released into the atmosphere when the synthetic gypsum material is used as a feedstock for wallboard production. The project is being co-funded by the U.S. DOE National Energy Technology Laboratory (Cooperative Agreement DE-FC26-04NT42080), USG Corporation, and EPRI. USG Corporation is the prime contractor, and URS Group is a subcontractor. The project scope includes five discrete tasks, each conducted at various USG wallboard plants using synthetic gypsum from different FGD systems. The five tasks were to include (1) a baseline test, then variations representing differing power plant (2) emissions control configurations, (3) treatment of fine gypsum particles, (4) coal types, and (5) FGD reagent types. However, Task 5, which was to evaluate gypsum produced from an alternate FGD reagent, could not be conducted as planned. Instead, Task 5 was conducted at conditions similar to a previous task, Task 3, although with gypsum from an alternate FGD system. In this project, process stacks in the wallboard plant have been sampled using the Ontario Hydro method. The stack locations sampled for each task include a dryer for the wet gypsum as it enters the plant and a gypsum calciner. The stack of the dryer for the wet wallboard product was also tested as part of this task, and was tested as part of Tasks 1 and 4. Also at each site, in-stream process samples were collected and analyzed for mercury concentration before and after each significant step in wallboard production. The Ontario Hydro results, process sample mercury concentration data, and process data were used to construct mercury mass balances across the wallboard plants. Task 5 was conducted at a wallboard plant processing synthetic gypsum from a power plant that fires Eastern bituminous coal. The power plant is equipped with a selective catalytic reduction (SCR) system for NOX emissions control, but the SCR was bypassed during the time period the gypsum tested was produced. The power plant has a single-loop, open spray tower, limestone reagent FGD system, with forced oxidation conducted in a reaction tank integral with the FGD absorber. The FGD system has gypsum fines blow down as part of the dewatering step. Gypsum fines blow down is believed to be an important variable that impacts the amount of mercury in the gypsum byproduct and possibly its stability during the wallboard process. The results of the Task 5 stack testing, as measured by the Ontario Hydro method, detected that an average of 51% of the incoming mercury in the FGD gypsum was emitted during wallboard production. These losses were distributed as 2% or less each across the wet gypsum dryer and product wallboard dryer, and about 50% across the gypsum calciner. Emissions were similar to what Task 3 results showed, on both a percentage and a mass basis, for gypsum produced by a power plant firing bituminous coal and also having gypsum fines blow down as part of the FGD dewatering scheme. As was seen in the Task 1 through 4 results, most of the mercury detected in the stack testing on the wet gypsum dryer and kettle calciner was in the form of elemental mercury. In the wallboard dryer kiln, a more significant percentage of the mercury detected was in the oxidized form, particularly from the stack near the product discharge end of the kiln. However, this represented a very small percentage of the overall mercury loss.« less

The postural stability of children with foetal alcohol spectrum disorders during one-leg stance: A feasibility study

PubMed Central

2018-01-01

Background Postural control may be impaired in children with foetal alcohol spectrum disorders (FASD). The study assessed the protocol feasibility in terms of (1) recruiting children with FASD in a rural, small town; (2) using the measurement instruments in a real-life setting; (3) the one-leg standing (OLS) task and (4) presenting preliminary results on postural stability of children with and without FASD. Methods Nine-year-old children diagnosed with and without FASD were invited to participate. Twenty-eight children performed OLS. Feasibility outcomes included recruitment, measurement instrument use and task instruction. Postural stability outcomes included standing duration, centre of pressure (COP) and body segment acceleration. Results Participants recruitment was feasible in terms of the (1) ability to sample a reasonable participant number in a rural town setting and the capacity to increase the sample size if more schools are included in the sampling frame and (2) use of assent and consent forms that were appropriate for this population. The measurement instruments were user-friendly, cost-effective and time-efficient. Instructions for the task require amendment to address foot placement of the non-weight–bearing leg. There was a significant difference between cases and controls on mean COP velocity (p = 0.001) and the pelvis segment acceleration in the mediolateral direction (p = 0.01) and the anteroposterior direction (p = 0.027). The control children took longer to achieve postural control. The girls demonstrated a significant difference for the COP anteroposterior displacement (p = 0.008) and velocity (p = 0.049). Conclusions The recruitment of children with and without FASD in a rural, small town and the administration of measurement instruments in a real-life, school-based setting was feasible. However, the verbal instructions for the task require revision. The male control group took longer to achieve postural control because the task was performed differently between the two groups. However, the case girls were slower to achieve postural control than control girls though performing the task similarly. PMID:29707515

The Interaction of Temporal Generalization Gradients Predicts the Context Effect

ERIC Educational Resources Information Center

de Castro, Ana Catarina; Machado, Armando

2012-01-01

In a temporal double bisection task, animals learn two discriminations. In the presence of Red and Green keys, responses to Red are reinforced after 1-s samples and responses to Green are reinforced after 4-s samples; in the presence of Blue and Yellow keys, responses to Blue are reinforced after 4-s samples and responses to Yellow are reinforced…

Asymmetrical Sample Training and Asymmetrical Retention Functions in One-to-One and Many-to-One Matching in Pigeons

ERIC Educational Resources Information Center

Grant, Douglas S.

2006-01-01

Pigeons were trained in a matching task with either color (group color-first) or line (group line-first) samples. After asymmetrical training in which each group was initially trained with the same sample on all trials, marked retention asymmetries were obtained. In both groups, accuracy dropped precipitously on trials involving the initially…

Cortisol and Anti-social Behavior in Early Adolescence: The Role of Gender in an Economically Disadvantaged Sample

PubMed Central

Kobak, Roger; Zajac, Kristyn; Levine, Seymour

2014-01-01

This study examines the relation between adolescents’ anti-social behaviors and adrenocortical activity during a laboratory visit in a sample of economically disadvantaged families (N = 116, ages 12 – 14, 51% female). Pre-task cortisol levels indexed adolescents’ pre-challenge response to the lab visit, while adolescents’ response to a conflict discussion with their caregivers was indexed with residualized change in pre- to post- conflict cortisol levels. A trait measure of anti-social behavior (derived from parent, teacher, and self-reports) was associated with lower pre-task cortisol levels but greater cortisol response to the conflict discussion. Gender moderated anti-social adolescents’ cortisol response to the conflict discussion with girls who reported more covert risky problem behaviors showing an increased cortisol response. The findings suggest that, while anti-social adolescents had lower pre-task cortisol levels, conflict discussions with caregivers present a unique challenge to anti-social girls compared with anti-social boys. PMID:19338699

Expectancy bias in anxious samples

PubMed Central

Cabeleira, Cindy M.; Steinman, Shari A.; Burgess, Melissa M.; Bucks, Romola S.; MacLeod, Colin; Melo, Wilson; Teachman, Bethany A.

2014-01-01

While it is well documented that anxious individuals have negative expectations about the future, it is unclear what cognitive processes give rise to this expectancy bias. Two studies are reported that use the Expectancy Task, which is designed to assess expectancy bias and illuminate its basis. This task presents individuals with valenced scenarios (Positive Valence, Negative Valence, or Conflicting Valence), and then evaluates their tendency to expect subsequent future positive relative to negative events. The Expectancy Task was used with low and high trait anxious (Study 1: N = 32) and anxiety sensitive (Study 2: N = 138) individuals. Results suggest that in the context of physical concerns, both high anxious samples display a less positive expectancy bias. In the context of social concerns, high trait anxious individuals display a negative expectancy bias only when negatively valenced information was previously presented. Overall, this suggests that anxious individuals display a less positive expectancy bias, and that the processes that give rise to this bias may vary by type of situation (e.g., social or physical) or anxiety difficulty. PMID:24798678

Ego Depletion in Real-Time: An Examination of the Sequential-Task Paradigm.

PubMed

Arber, Madeleine M; Ireland, Michael J; Feger, Roy; Marrington, Jessica; Tehan, Joshua; Tehan, Gerald

2017-01-01

Current research into self-control that is based on the sequential task methodology is currently at an impasse. The sequential task methodology involves completing a task that is designed to tax self-control resources which in turn has carry-over effects on a second, unrelated task. The current impasse is in large part due to the lack of empirical research that tests explicit assumptions regarding the initial task. Five studies test one key, untested assumption underpinning strength (finite resource) models of self-regulation: Performance will decline over time on a task that depletes self-regulatory resources. In the aftermath of high profile replication failures using a popular letter-crossing task and subsequent criticisms of that task, the current studies examined whether depletion effects would occur in real time using letter-crossing tasks that did not invoke habit-forming and breaking, and whether these effects were moderated by administration type (paper and pencil vs. computer administration). Sample makeup and sizes as well as response formats were also varied across the studies. The five studies yielded a clear and consistent pattern of increasing performance deficits (errors) as a function of time spent on task with generally large effects and in the fifth study the strength of negative transfer effects to a working memory task were related to individual differences in depletion. These results demonstrate that some form of depletion is occurring on letter-crossing tasks though whether an internal regulatory resource reservoir or some other factor is changing across time remains an important question for future research.

Ego Depletion in Real-Time: An Examination of the Sequential-Task Paradigm

PubMed Central

Arber, Madeleine M.; Ireland, Michael J.; Feger, Roy; Marrington, Jessica; Tehan, Joshua; Tehan, Gerald

2017-01-01

Current research into self-control that is based on the sequential task methodology is currently at an impasse. The sequential task methodology involves completing a task that is designed to tax self-control resources which in turn has carry-over effects on a second, unrelated task. The current impasse is in large part due to the lack of empirical research that tests explicit assumptions regarding the initial task. Five studies test one key, untested assumption underpinning strength (finite resource) models of self-regulation: Performance will decline over time on a task that depletes self-regulatory resources. In the aftermath of high profile replication failures using a popular letter-crossing task and subsequent criticisms of that task, the current studies examined whether depletion effects would occur in real time using letter-crossing tasks that did not invoke habit-forming and breaking, and whether these effects were moderated by administration type (paper and pencil vs. computer administration). Sample makeup and sizes as well as response formats were also varied across the studies. The five studies yielded a clear and consistent pattern of increasing performance deficits (errors) as a function of time spent on task with generally large effects and in the fifth study the strength of negative transfer effects to a working memory task were related to individual differences in depletion. These results demonstrate that some form of depletion is occurring on letter-crossing tasks though whether an internal regulatory resource reservoir or some other factor is changing across time remains an important question for future research. PMID:29018390

Sex Differences in Spatial Memory in Brown-Headed Cowbirds: Males Outperform Females on a Touchscreen Task

PubMed Central

Guigueno, Mélanie F.; MacDougall-Shackleton, Scott A.; Sherry, David F.

2015-01-01

Spatial cognition in females and males can differ in species in which there are sex-specific patterns in the use of space. Brown-headed cowbirds are brood parasites that show a reversal of sex-typical space use often seen in mammals. Female cowbirds, search for, revisit and parasitize hosts nests, have a larger hippocampus than males and have better memory than males for a rewarded location in an open spatial environment. In the current study, we tested female and male cowbirds in breeding and non-breeding conditions on a touchscreen delayed-match-to-sample task using both spatial and colour stimuli. Our goal was to determine whether sex differences in spatial memory in cowbirds generalizes to all spatial tasks or is task-dependant. Both sexes performed better on the spatial than on the colour touchscreen task. On the spatial task, breeding males outperformed breeding females. On the colour task, females and males did not differ, but females performed better in breeding condition than in non-breeding condition. Although female cowbirds were observed to outperform males on a previous larger-scale spatial task, males performed better than females on a task testing spatial memory in the cowbirds’ immediate visual field. Spatial abilities in cowbirds can favour males or females depending on the type of spatial task, as has been observed in mammals, including humans. PMID:26083573

Multitask TSK fuzzy system modeling by mining intertask common hidden structure.

PubMed

Jiang, Yizhang; Chung, Fu-Lai; Ishibuchi, Hisao; Deng, Zhaohong; Wang, Shitong

2015-03-01

The classical fuzzy system modeling methods implicitly assume data generated from a single task, which is essentially not in accordance with many practical scenarios where data can be acquired from the perspective of multiple tasks. Although one can build an individual fuzzy system model for each task, the result indeed tells us that the individual modeling approach will get poor generalization ability due to ignoring the intertask hidden correlation. In order to circumvent this shortcoming, we consider a general framework for preserving the independent information among different tasks and mining hidden correlation information among all tasks in multitask fuzzy modeling. In this framework, a low-dimensional subspace (structure) is assumed to be shared among all tasks and hence be the hidden correlation information among all tasks. Under this framework, a multitask Takagi-Sugeno-Kang (TSK) fuzzy system model called MTCS-TSK-FS (TSK-FS for multiple tasks with common hidden structure), based on the classical L2-norm TSK fuzzy system, is proposed in this paper. The proposed model can not only take advantage of independent sample information from the original space for each task, but also effectively use the intertask common hidden structure among multiple tasks to enhance the generalization performance of the built fuzzy systems. Experiments on synthetic and real-world datasets demonstrate the applicability and distinctive performance of the proposed multitask fuzzy system model in multitask regression learning scenarios.

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

Peters, T. B.; Bannochie, C. J.

Savannah River National Laboratory (SRNL) analyzed samples from Tank 21H in support of verification of Macrobatch (Salt Batch) 11 for the Interim Salt Disposition Program (ISDP) for processing. This document reports characterization data on the samples of Tank 21H and fulfills the requirements of Deliverable 3 of the Technical Task Request (TTR).

Prefrontal Neuronal Responses during Audiovisual Mnemonic Processing

PubMed Central

Hwang, Jaewon

2015-01-01

During communication we combine auditory and visual information. Neurophysiological research in nonhuman primates has shown that single neurons in ventrolateral prefrontal cortex (VLPFC) exhibit multisensory responses to faces and vocalizations presented simultaneously. However, whether VLPFC is also involved in maintaining those communication stimuli in working memory or combining stored information across different modalities is unknown, although its human homolog, the inferior frontal gyrus, is known to be important in integrating verbal information from auditory and visual working memory. To address this question, we recorded from VLPFC while rhesus macaques (Macaca mulatta) performed an audiovisual working memory task. Unlike traditional match-to-sample/nonmatch-to-sample paradigms, which use unimodal memoranda, our nonmatch-to-sample task used dynamic movies consisting of both facial gestures and the accompanying vocalizations. For the nonmatch conditions, a change in the auditory component (vocalization), the visual component (face), or both components was detected. Our results show that VLPFC neurons are activated by stimulus and task factors: while some neurons simply responded to a particular face or a vocalization regardless of the task period, others exhibited activity patterns typically related to working memory such as sustained delay activity and match enhancement/suppression. In addition, we found neurons that detected the component change during the nonmatch period. Interestingly, some of these neurons were sensitive to the change of both components and therefore combined information from auditory and visual working memory. These results suggest that VLPFC is not only involved in the perceptual processing of faces and vocalizations but also in their mnemonic processing. PMID:25609614

Speech Discrimination Difficulties in High-Functioning Autism Spectrum Disorder Are Likely Independent of Auditory Hypersensitivity

PubMed Central

Dunlop, William A.; Enticott, Peter G.; Rajan, Ramesh

2016-01-01

Autism Spectrum Disorder (ASD), characterized by impaired communication skills and repetitive behaviors, can also result in differences in sensory perception. Individuals with ASD often perform normally in simple auditory tasks but poorly compared to typically developed (TD) individuals on complex auditory tasks like discriminating speech from complex background noise. A common trait of individuals with ASD is hypersensitivity to auditory stimulation. No studies to our knowledge consider whether hypersensitivity to sounds is related to differences in speech-in-noise discrimination. We provide novel evidence that individuals with high-functioning ASD show poor performance compared to TD individuals in a speech-in-noise discrimination task with an attentionally demanding background noise, but not in a purely energetic noise. Further, we demonstrate in our small sample that speech-hypersensitivity does not appear to predict performance in the speech-in-noise task. The findings support the argument that an attentional deficit, rather than a perceptual deficit, affects the ability of individuals with ASD to discriminate speech from background noise. Finally, we piloted a novel questionnaire that measures difficulty hearing in noisy environments, and sensitivity to non-verbal and verbal sounds. Psychometric analysis using 128 TD participants provided novel evidence for a difference in sensitivity to non-verbal and verbal sounds, and these findings were reinforced by participants with ASD who also completed the questionnaire. The study was limited by a small and high-functioning sample of participants with ASD. Future work could test larger sample sizes and include lower-functioning ASD participants. PMID:27555814

Fiscal year 1980-81 implementation plan in support of technical development and integration of sampling and aggregation procedures. [crop acreage estimation

NASA Technical Reports Server (NTRS)

1981-01-01

The specific objectives of the FY 1980-81 tasks are: (1) further refinements to the weighted aggregation procedure; (2) improved approaches for estimating within-stratum variance; (3) more intensive investigation of alternative sampling strategies such as full-frame sampling strategy, and (4) further developments in regard to a simulated approach for assessing the performance of the overall designed sampling and aggregation system.

Fate of Mercury in Synthetic Gypsum Used for Wallboard Production

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

Jessica Sanderson; Gary M. Blythe; Mandi Richardson

2006-12-01

This report presents and discusses results from Task 6 of the study 'Fate of Mercury in Synthetic Gypsum Used for Wallboard Production,' performed at a full-scale commercial wallboard plant. Synthetic gypsum produced by wet flue gas desulfurization (FGD) systems on coal-fired power plants is commonly used in the manufacture of wallboard. This practice has long benefited the environment by recycling the FGD gypsum byproduct, which is becoming available in increasing quantities, decreasing the need to landfill this material, and increasing the sustainable design of the wallboard product. However, new concerns have arisen as recent mercury control strategies involve the capturemore » of mercury in FGD systems. The objective of this study is to determine whether any mercury is released into the atmosphere when the synthetic gypsum material is used as a feedstock for wallboard production. The project is being co-funded by the U.S. DOE National Energy Technology Laboratory (Cooperative Agreement DE-FC26-04NT42080), USG Corporation, and EPRI. USG Corporation is the prime contractor, and URS Group is a subcontractor. The project scope now includes six discrete tasks, each conducted at various USG wallboard plants using synthetic gypsum from different FGD systems. The project was originally composed of five tasks, which were to include (1) a baseline test, then variations representing differing power plant: (2) emissions control configurations, (3) treatment of fine gypsum particles, (4) coal types, and (5) FGD reagent types. However, Task 5, which was to include testing with an alternate FGD reagent, could not be conducted as planned. Instead, Task 5 was conducted at conditions similar to Task 3, although with gypsum from an alternate FGD system. Subsequent to conducting Task 5 under these revised conditions, an opportunity arose to test gypsum produced at the same FGD system, but with an additive (Degussa Corporation's TMT-15) being used in the FGD system. TMT-15 was expected to impact the stability of mercury in synthetic gypsum used to produce wallboard, so Task 6 was added to the project to test this theory. In this project, process stacks in the wallboard plant have been sampled using the Ontario Hydro method. For every task, the stack locations sampled have included a dryer for the wet gypsum as it enters the plant and a gypsum calciner. For Tasks 1, 4, 5 and 6, the stack of the dryer for the wet wallboard product was also tested. Also at each site, in-stream process samples were collected and analyzed for mercury concentration before and after each significant step in wallboard production. The Ontario Hydro results, process sample mercury concentration data, and process data were used to construct mercury mass balances across the wallboard plants. Task 6 was conducted at a wallboard plant processing synthetic gypsum from a power plant that fires Eastern bituminous coal. The power plant has a single-loop, open spray tower limestone forced oxidation FGD system, with the forced oxidation conducted in the reaction tank integral with the FGD absorber. The FGD system has gypsum fines blow down as part of the dewatering step. The power plant is equipped with a selective catalytic reduction (SCR) system for NOX emissions control, and the SCR was in service during the time period the gypsum tested was produced. Also, as mentioned above, Degussa additive TMT-15 was being added to the FGD system when this gypsum was produced. The results of the Task 6 stack testing, as measured by the Ontario Hydro method, detected that an average of 55% of the incoming mercury was emitted during wallboard production. These losses were distributed as about 4% across the dryer mill, 6% across the board dryer kiln, and 45% across the kettle calciner. Emissions were similar to what Task 5 results showed on a percentage basis, but about 30% lower on a mass basis. The same power plant FGD system produced the synthetic gypsum used in Task 5 (with no use of TMT-15) and in Task 6 (with TMT-15 added to the FGD system). The lower emissions on a mass basis appeared to be due to lower average mercury content in the gypsum being processed. It is not certain whether the lower average mercury content in the gypsum was an effect of TMT-15 addition to the FGD system. As was seen in the Task 1 through 5 results, most of the mercury detected in the Ontario Hydro method stack testing was in the form of elemental mercury.« less

Factors affecting articulation skills in children with velocardiofacial syndrome and children with cleft palate or velopharyngeal dysfunction: A preliminary report

PubMed Central

Baylis, Adriane L.; Munson, Benjamin; Moller, Karlind T.

2010-01-01

Objective To examine the influence of speech perception, cognition, and implicit phonological learning on articulation skills of children with Velocardiofacial syndrome (VCFS) and children with cleft palate or velopharyngeal dysfunction (VPD). Design Cross-sectional group experimental design. Participants 8 children with VCFS and 5 children with non-syndromic cleft palate or VPD. Methods and Measures All children participated in a phonetic inventory task, speech perception task, implicit priming nonword repetition task, conversational sample, nonverbal intelligence test, and hearing screening. Speech tasks were scored for percentage of phonemes correctly produced. Group differences and relations among measures were examined using nonparametric statistics. Results Children in the VCFS group demonstrated significantly poorer articulation skills and lower standard scores of nonverbal intelligence compared to the children with cleft palate or VPD. There were no significant group differences in speech perception skills. For the implicit priming task, both groups of children were more accurate in producing primed nonwords than unprimed nonwords. Nonverbal intelligence and severity of velopharyngeal inadequacy for speech were correlated with articulation skills. Conclusions In this study, children with VCFS had poorer articulation skills compared to children with cleft palate or VPD. Articulation difficulties seen in the children with VCFS did not appear to be associated with speech perception skills or the ability to learn new phonological representations. Future research should continue to examine relationships between articulation, cognition, and velopharyngeal dysfunction in a larger sample of children with cleft palate and VCFS. PMID:18333642

Resting cardiac vagal tone predicts intraindividual reaction time variability during an attention task in a sample of young and healthy adults.

PubMed

Williams, DeWayne P; Thayer, Julian F; Koenig, Julian

2016-12-01

Intraindividual reaction time variability (IIV), defined as the variability in trial-to-trial response times, is thought to serve as an index of central nervous system function. As such, greater IIV reflects both poorer executive brain function and cognitive control, in addition to lapses in attention. Resting-state vagally mediated heart rate variability (vmHRV), a psychophysiological index of self-regulatory abilities, has been linked with executive brain function and cognitive control such that those with greater resting-state vmHRV often perform better on cognitive tasks. However, research has yet to investigate the direct relationship between resting vmHRV and task IIV. The present study sought to examine this relationship in a sample of 104 young and healthy participants who first completed a 5-min resting-baseline period during which resting-state vmHRV was assessed. Participants then completed an attentional (target detection) task, where reaction time, accuracy, and trial-to-trial IIV were obtained. Results showed resting vmHRV to be significantly related to IIV, such that lower resting vmHRV predicted higher IIV on the task, even when controlling for several covariates (including mean reaction time and accuracy). Overall, our results provide further evidence for the link between resting vmHRV and cognitive control, and extend these notions to the domain of lapses in attention, as indexed by IIV. Implications and recommendations for future research on resting vmHRV and cognition are discussed. © 2016 Society for Psychophysiological Research.

Deletion of the GluA1 AMPA receptor subunit impairs recency-dependent object recognition memory

PubMed Central

Sanderson, David J.; Hindley, Emma; Smeaton, Emily; Denny, Nick; Taylor, Amy; Barkus, Chris; Sprengel, Rolf; Seeburg, Peter H.; Bannerman, David M.

2011-01-01

Deletion of the GluA1 AMPA receptor subunit impairs short-term spatial recognition memory. It has been suggested that short-term recognition depends upon memory caused by the recent presentation of a stimulus that is independent of contextual–retrieval processes. The aim of the present set of experiments was to test whether the role of GluA1 extends to nonspatial recognition memory. Wild-type and GluA1 knockout mice were tested on the standard object recognition task and a context-independent recognition task that required recency-dependent memory. In a first set of experiments it was found that GluA1 deletion failed to impair performance on either of the object recognition or recency-dependent tasks. However, GluA1 knockout mice displayed increased levels of exploration of the objects in both the sample and test phases compared to controls. In contrast, when the time that GluA1 knockout mice spent exploring the objects was yoked to control mice during the sample phase, it was found that GluA1 deletion now impaired performance on both the object recognition and the recency-dependent tasks. GluA1 deletion failed to impair performance on a context-dependent recognition task regardless of whether object exposure in knockout mice was yoked to controls or not. These results demonstrate that GluA1 is necessary for nonspatial as well as spatial recognition memory and plays an important role in recency-dependent memory processes. PMID:21378100

Results Of Hg Speciation Testing On DWPF SMECT-1, SMECT-3, And SMECT-5 Samples

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

Bannochie, C.

2016-01-07

The Savannah River National Laboratory (SRNL) was tasked with preparing and shipping samples for Hg speciation by Eurofins Frontier Global Sciences, Inc. in Seattle, WA on behalf of the Savannah River Remediation (SRR) Mercury Task Team. The thirteenth shipment of samples was designated to include Defense Waste Processing Facility (DWPF) Slurry Mix Evaporator Condensate Tank (SMECT) from Sludge Receipt and Adjustment Tank (SRAT) Batch 736 and 738 samples. Triplicate samples of each material were prepared for this shipment. Each replicate was analyzed for seven Hg species: total Hg, total soluble (dissolved) Hg, elemental Hg [Hg(0)], ionic (inorganic) Hg [Hg(I) andmore » Hg(II)], methyl Hg [CH 3Hg-X, where X is a counter anion], ethyl Hg [CH 3CH 2-Hg-X, where X is a counter anion], and dimethyl Hg [(CH 3) 2Hg]. The difference between the total Hg and total soluble Hg measurements gives the particulate Hg concentration, i.e. Hg adsorbed to the surface of particulate matter in the sample but without resolution of the specific adsorbed species. The average concentrations of Hg species in the aqueous samples derived from Eurofins reported data corrected for dilutions performed by SRNL are tabulated.« less

Failure to replicate depletion of self-control.

PubMed

Xu, Xiaomeng; Demos, Kathryn E; Leahey, Tricia M; Hart, Chantelle N; Trautvetter, Jennifer; Coward, Pamela; Middleton, Kathryn R; Wing, Rena R

2014-01-01

The limited resource or strength model of self-control posits that the use of self-regulatory resources leads to depletion and poorer performance on subsequent self-control tasks. We conducted four studies (two with community samples, two with young adult samples) utilizing a frequently used depletion procedure (crossing out letters protocol) and the two most frequently used dependent measures of self-control (handgrip perseverance and modified Stroop). In each study, participants completed a baseline self-control measure, a depletion or control task (randomized), and then the same measure of self-control a second time. There was no evidence for significant depletion effects in any of these four studies. The null results obtained in four attempts to replicate using strong methodological approaches may indicate that depletion has more limited effects than implied by prior publications. We encourage further efforts to replicate depletion (particularly among community samples) with full disclosure of positive and negative results.

Dermal, inhalation, and internal exposure to 1,6-HDI and its oligomers in car body repair shop workers and industrial spray painters.

PubMed

Pronk, A; Yu, F; Vlaanderen, J; Tielemans, E; Preller, L; Bobeldijk, I; Deddens, J A; Latza, U; Baur, X; Heederik, D

2006-09-01

To study inhalation and dermal exposure to hexamethylene diisocyanate (HDI) and its oligomers as well as personal protection equipment (PPE) use during task performance in conjunction with urinary hexamethylene diamine (HDA) in car body repair shop workers and industrial spray painters. Personal task based inhalation samples (n = 95) were collected from six car body repair shops and five industrial painting companies using impingers with di-n-butylamine (DBA) in toluene. In parallel, dermal exposure was assessed using nitril rubber gloves. Gloves were submerged into DBA in toluene after sampling. Analysis for HDI and its oligomers was performed by LC-MS/MS. Urine samples were collected from 55 workers (n = 291) and analysed for HDA by GC-MS. Inhalation exposure was strongly associated with tasks during which aerosolisation occurs. Dermal exposure occurred during tasks that involve direct handling of paint. In car body repair shops associations were found between detectable dermal exposure and glove use (odds ratio (OR) 0.22, 95% confidence interval (CI) 0.09 to 0.57) and inhalation exposure level (OR 1.34, 95% CI 0.97 to 1.84 for a 10-fold increase). HDA in urine could be demonstrated in 36% and 10% of car body repair shop workers and industrial painting company workers respectively. In car body repair shops, the frequency of detectable HDA was significantly elevated at the end of the working day (OR 2.13, 95% CI 1.07 to 4.22 for 3-6 pm v 0-8 am). In both branches HDA was detected in urine of approximately 25% of the spray painters. In addition HDA was detected in urine of a large proportion of non-spray painters in car body repair shops. Although (spray) painting with lacquers containing isocyanate hardeners results in the highest external exposures to HDI and oligomers, workers that do not perform paint related tasks may also receive a considerable internal dose.

Individualized behavioral assessments and maternal ratings of mastery motivation in mental age-matched toddlers with and without motor delay.

PubMed

Wang, Pei-Jung; Morgan, George A; Hwang, Ai-Wen; Liao, Hua-Fang

2013-01-01

Mastery motivation is a precursor of future developmental outcomes. Evidence about whether toddlers with motor delay have lower mastery motivation is inconclusive. The purpose of this study was to examine differences between mental age-matched toddlers with and without motor delay on various mastery motivation indicators. A mental age- and sex-matched case-control study was performed. Twenty-two children with motor delay, aged 23 to 47 months, and 22 children who were developing typically, aged 15 to 29 months, were recruited. Persistence and mastery pleasure were measured with behavioral tasks that were moderately challenging for each child and with maternal ratings using the Dimensions of Mastery Questionnaire (DMQ). The DMQ was rated by each child's mother based on her perception of her child's motivation. Two types of structured tasks (a puzzle and a cause-effect toy selected to be moderately challenging for each child) were administered in a laboratory setting and recorded on videos. Paired t tests or Wilcoxon signed rank tests were used to examine group differences in persistence and mastery pleasure (α=.007, 2-tailed). Children with motor delay were rated lower on DMQ persistence than the typically developing group, but they did not show significantly lower persistence on the structured tasks. There were no significant differences in mastery pleasure between the 2 groups on either measure. Large within-sample variability on the tasks and small sample size makes subgroup analysis (eg, different severities) difficult. Toddlers with motor delay did not show lower persistence and pleasure when given tasks that were moderately challenging; however, their mothers tended to view them as having lower motivation. Clinicians and parents should provide appropriately challenging tasks to increase children's success and motivation.

Reliability and Validity of Nonsymbolic and Symbolic Comparison Tasks in School-Aged Children.

PubMed

Castro, Danilka; Estévez, Nancy; Gómez, David; Dartnell, Pablo Ricardo

2017-12-04

Basic numerical processing has been regularly assessed using numerical nonsymbolic and symbolic comparison tasks. It has been assumed that these tasks index similar underlying processes. However, the evidence concerning the reliability and convergent validity across different versions of these tasks is inconclusive. We explored the reliability and convergent validity between two numerical comparison tasks (nonsymbolic vs. symbolic) in school-aged children. The relations between performance in both tasks and mental arithmetic were described and a developmental trajectories' analysis was also conducted. The influence of verbal and visuospatial working memory processes and age was controlled for in the analyses. Results show significant reliability (p < .001) between Block 1 and 2 for nonsymbolic task (global adjusted RT (adjRT): r = .78, global efficiency measures (EMs): r = .74) and, for symbolic task (adjRT: r = .86, EMs: r = .86). Also, significant convergent validity between tasks (p < .001) for both adjRT (r = .71) and EMs (r = .70) were found after controlling for working memory and age. Finally, it was found the relationship between nonsymbolic and symbolic efficiencies varies across the sample's age range. Overall, these findings suggest both tasks index the same underlying cognitive architecture and are appropriate to explore the Approximate Number System (ANS) characteristics. The evidence supports the central role of ANS in arithmetic efficiency and suggests there are differences across the age range assessed, concerning the extent to which efficiency in nonsymbolic and symbolic tasks reflects ANS acuity.

Stroop interference in a delayed match-to-sample task: evidence for semantic competition

PubMed Central

Sturz, Bradley R.; Green, Marshall L.; Locker, Lawrence; Boyer, Ty W.

2013-01-01

Discussions of the source of the Stroop interference effect continue to pervade the literature. Semantic competition posits that interference results from competing semantic activation of word and color dimensions of the stimulus prior to response selection. Response competition posits that interference results from competing responses for articulating the word dimension vs. the color dimension at the time of response selection. We embedded Stroop stimuli into a delayed match-to-sample (DMTS) task in an attempt to test semantic and response competition accounts of the interference effect. Participants viewed a sample color word in black or colored fonts that were congruent or incongruent with respect to the color word itself. After a 5 s delay, participants were presented with two targets (i.e., a match and a foil) and were instructed to select the correct match. We probed each dimension independently during target presentations via color targets (i.e., two colors) or word targets (i.e., two words) and manipulated whether the semantic content of the foil was related to the semantic content of the irrelevant sample dimension (e.g., word sample “red” in blue font with the word “red” as the match and the word “blue” as the foil). We provide evidence for Stroop interference such that response times (RTs) increased for incongruent trials even in the presence of a response option with semantic content unrelated to the semantic content of the irrelevant sample dimension. Accuracy also deteriorated during the related foil trials. A follow-up experiment with a 10 s delay between sample and targets replicated the results. Results appear to provide converging evidence for Stroop interference in a DMTS task in a manner that is consistent with an explanation based upon semantic competition and inconsistent with an explanation based upon response competition. PMID:24298264

Pharmacy in transition: A work sampling study of community pharmacists using smartphone technology.

PubMed

van de Pol, Jeroen M; Geljon, Jurjen G; Belitser, Svetlana V; Frederix, Geert W J; Hövels, Anke M; Bouvy, Marcel L

2018-03-09

The nature of community pharmacy is changing, shifting from the preparation and distribution of medicines to the provision of cognitive pharmaceutical services (CPS); however, often the provision of traditional services leaves little time for innovative services. This study investigated the time community pharmacists spend on the tasks and activities of daily practice and to what extent they are able to implement CPS-related services in daily practice. Self-reporting work sampling was used to register the activities of community pharmacists. A smartphone application, designed specifically for this purpose, alerted participants to register their current activity five times per working day for 6 weeks. Participants also completed an online survey about baseline characteristics. Ninety-one Dutch community pharmacists provided work-sampling data (7848 registered activities). Overall, 51.5% of their time was spent on professional activities, 35.4% on semi-professional activities, and 13.1% on non-professional activities. The proportion of time devoted to CPS decreased during the workweek, whereas the time spent on traditional task increased. This study shows it is feasible to collect work-sampling data using smartphone technology. Community pharmacists spent almost half of their time on semi-professional and non-professional activities, activities that could be delegated to other staff members. In practice, the transition to CPS is hampered by competing traditional tasks, which prevents community pharmacists from profiling themselves as pharmaceutical experts in daily practice. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Design of a practical model-observer-based image quality assessment method for x-ray computed tomography imaging systems

PubMed Central

Tseng, Hsin-Wu; Fan, Jiahua; Kupinski, Matthew A.

2016-01-01

Abstract. The use of a channelization mechanism on model observers not only makes mimicking human visual behavior possible, but also reduces the amount of image data needed to estimate the model observer parameters. The channelized Hotelling observer (CHO) and channelized scanning linear observer (CSLO) have recently been used to assess CT image quality for detection tasks and combined detection/estimation tasks, respectively. Although the use of channels substantially reduces the amount of data required to compute image quality, the number of scans required for CT imaging is still not practical for routine use. It is our desire to further reduce the number of scans required to make CHO or CSLO an image quality tool for routine and frequent system validations and evaluations. This work explores different data-reduction schemes and designs an approach that requires only a few CT scans. Three different kinds of approaches are included in this study: a conventional CHO/CSLO technique with a large sample size, a conventional CHO/CSLO technique with fewer samples, and an approach that we will show requires fewer samples to mimic conventional performance with a large sample size. The mean value and standard deviation of areas under ROC/EROC curve were estimated using the well-validated shuffle approach. The results indicate that an 80% data reduction can be achieved without loss of accuracy. This substantial data reduction is a step toward a practical tool for routine-task-based QA/QC CT system assessment. PMID:27493982

Anticipatory processing in social anxiety: Investigation using attentional control theory.

PubMed

Sluis, Rachel A; Boschen, Mark J; Neumann, David L; Murphy, Karen

2017-12-01

Cognitive models of social anxiety disorder (SAD) emphasize anticipatory processing as a prominent maintaining factor occurring before social-evaluative events. While anticipatory processing is a maladaptive process, the cognitive mechanisms that underlie ineffective control of attention are still unclear. The present study tested predictions derived from attentional control theory in a sample of undergraduate students high and low on social anxiety symptoms. Participants were randomly assigned to either engage in anticipatory processing prior to a threat of a speech task or a control condition with no social evaluative threat. After completing a series of questionnaires, participants performed pro-saccades and antisaccades in response to peripherally presented facial expressions presented in either single-task or mixed-task blocks. Correct antisaccade latencies were longer than correct pro-saccade latencies in-line with attentional control theory. High socially anxious individuals who anticipated did not exhibit impairment on the inhibition and shifting functions compared to high socially anxious individuals who did not anticipate or low socially anxious individuals in either the anticipatory or control condition. Low socially anxious individuals who anticipated exhibited shorter antisaccade latencies and a switch benefit compared to low socially anxious individuals in the control condition. The study used an analogue sample; however findings from analogue samples are generally consistent with clinical samples. The findings suggest that social threat induced anticipatory processing facilitates executive functioning for low socially anxious individuals when anticipating a social-evaluative situation. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Advanced Curation Preparation for Mars Sample Return and Cold Curation

NASA Technical Reports Server (NTRS)

Fries, M. D.; Harrington, A. D.; McCubbin, F. M.; Mitchell, J.; Regberg, A. B.; Snead, C.

2017-01-01

NASA Curation is tasked with the care and distribution of NASA's sample collections, such as the Apollo lunar samples and cometary material collected by the Stardust spacecraft. Curation is also mandated to perform Advanced Curation research and development, which includes improving the curation of existing collections as well as preparing for future sample return missions. Advanced Curation has identified a suite of technologies and techniques that will require attention ahead of Mars sample return (MSR) and missions with cold curation (CCur) requirements, perhaps including comet sample return missions.

Color Filtering Localization for Three-Dimensional Underwater Acoustic Sensor Networks

PubMed Central

Liu, Zhihua; Gao, Han; Wang, Wuling; Chang, Shuai; Chen, Jiaxing

2015-01-01

Accurate localization of mobile nodes has been an important and fundamental problem in underwater acoustic sensor networks (UASNs). The detection information returned from a mobile node is meaningful only if its location is known. In this paper, we propose two localization algorithms based on color filtering technology called PCFL and ACFL. PCFL and ACFL aim at collaboratively accomplishing accurate localization of underwater mobile nodes with minimum energy expenditure. They both adopt the overlapping signal region of task anchors which can communicate with the mobile node directly as the current sampling area. PCFL employs the projected distances between each of the task projections and the mobile node, while ACFL adopts the direct distance between each of the task anchors and the mobile node. The proportion factor of distance is also proposed to weight the RGB values. By comparing the nearness degrees of the RGB sequences between the samples and the mobile node, samples can be filtered out. The normalized nearness degrees are considered as the weighted standards to calculate the coordinates of the mobile nodes. The simulation results show that the proposed methods have excellent localization performance and can localize the mobile node in a timely way. The average localization error of PCFL is decreased by about 30.4% compared to the AFLA method. PMID:25774706

Refining the multisystem view of the stress response: coordination among cortisol, alpha-amylase, and subjective stress in response to relationship conflict.

PubMed

Laurent, Heidemarie K; Powers, Sally I; Granger, Douglas A

2013-07-02

This study investigated associations among young adults' hypothalamic-pituitary-adrenal axis activity, autonomic nervous system activity, and subjective stress in response to interpersonal conflict to better characterize coordination across stress systems. Seven saliva samples were collected from 199 young adult opposite-sex couples before, during, and after they discussed an unresolved relationship conflict. Samples were later assayed for cortisol and alpha-amylase (sAA). Couples rated anticipatory stress prior to the conflict and perceived stress immediately following the task. Growth curve modeling was used to examine two possible levels of within-person coordination across physiological systems: alignment between cortisol and sAA responses throughout the sampling period ("matched phase coordination"), and association between overall levels of cortisol and sAA in response to conflict ("average level coordination"). Whereas both partners showed the former type of coordination, only women showed the latter type. Positive anticipation of the stressor predicted stronger cortisol-sAA matched phase coordination for women. Pre-task ratings related to women's sAA, and post-task ratings related to both partners' cortisol responses. Implications for a multisystem interpretation of normal and pathological responses to daily stress are discussed. Copyright © 2013 Elsevier Inc. All rights reserved.

A fluid response: Alpha-amylase reactions to acute laboratory stress are related to sample timing and saliva flow rate.

PubMed

Nagy, Tamás; van Lien, René; Willemsen, Gonneke; Proctor, Gordon; Efting, Marieke; Fülöp, Márta; Bárdos, György; Veerman, Enno C I; Bosch, Jos A

2015-07-01

Salivary alpha-amylase (sAA) is used as a sympathetic (SNS) stress marker, though its release is likely co-determined by SNS and parasympathetic (PNS) activation. The SNS and PNS show asynchronous changes during acute stressors, and sAA responses may thus vary with sample timing. Thirty-four participants underwent an eight-minute memory task (MT) and cold pressor task (CPT). Cardiovascular SNS (pre-ejection period, blood pressure) and PNS (heart rate variability) activity were monitored continuously. Unstimulated saliva was collected repeatedly during and after each laboratory stressor, and sAA concentration (U/ml) and secretion (U/minute) determined. Both stressors increased anxiety. The MT caused an immediate and continued cardiac SNS activation, but sAA concentration increased at task cessation only (+54%); i.e., when there was SNS-PNS co-activation. During the MT sAA secretion even decreased (-35%) in conjunction with flow rate and vagal tone. The CPT robustly increased blood pressure but not sAA. In summary, sAA fluctuations did not parallel changes in cardiac SNS activity or anxiety. sAA responses seem contingent on sample timing and flow rate, likely involving both SNS and PNS influences. Verification using other stressors and contexts seems warranted. Copyright © 2015 Elsevier B.V. All rights reserved.

Cognitive Predictors of Verbal Memory in a Mixed Clinical Pediatric Sample

PubMed Central

Jordan, Lizabeth L.; Tyner, Callie E.; Heaton, Shelley C.

2013-01-01

Verbal memory problems, along with other cognitive difficulties, are common in children diagnosed with neurological and/or psychological disorders. Historically, these “memory problems” have been poorly characterized and often present with a heterogeneous pattern of performance across memory processes, even within a specific diagnostic group. The current study examined archival neuropsychological data from a large mixed clinical pediatric sample in order to understand whether functioning in other cognitive areas (i.e., verbal knowledge, attention, working memory, executive functioning) may explain some of the performance variability seen across verbal memory tasks of the Children’s Memory Scale (CMS). Multivariate analyses revealed that among the cognitive functions examined, only verbal knowledge explained a significant amount of variance in overall verbal memory performance. Further univariate analyses examining the component processes of verbal memory indicated that verbal knowledge is specifically related to encoding, but not the retention or retrieval stages. Future research is needed to replicate these findings in other clinical samples, to examine whether verbal knowledge predicts performance on other verbal memory tasks and to explore whether these findings also hold true for visual memory tasks. Successful replication of the current study findings would indicate that interventions targeting verbal encoding deficits should include efforts to improve verbal knowledge. PMID:25379253

Gender and practical skill performance in science

NASA Astrophysics Data System (ADS)

Lock, Roger

The performance of 18 boys and 18 girls on four problem-solving tasks set in science contexts was compared. The tasks were administered in a one-to-one testing situation and assessments were made by direct observation, questioning, and by using written records. The tasks were valid and reliable, and the samples of boys and girls were matched for ability and curriculum background. Past studies have identified gender differences in performance on science tasks; however, this study found little evidence to support these findings. Few significant differences in performance were found. No gender differences were detected in observation, reporting, or planning skills, and there was no differential performance on the use of scientific language. Girls performed less well in relation to self-reliance, and performance differences on the interpretation skill approached significance with boys' performance superior.

Climate uniformity: its influence on team communication quality, task conflict, and team performance.

PubMed

González-Romá, Vicente; Hernández, Ana

2014-11-01

We investigated whether climate uniformity (the pattern of climate perceptions of organizational support within the team) is related to task conflict, team communication quality, and team performance. We used a sample composed of 141 bank branches and collected data at 3 time points. The results obtained showed that, after controlling for aggregate team climate, climate strength, and their interaction, a type of nonuniform climate pattern (weak dissimilarity) was directly related to task conflict and team communication quality. Teams with weak dissimilarity nonuniform patterns tended to show higher levels of task conflict and lower levels of team communication quality than teams with uniform climate patterns. The relationship between weak dissimilarity patterns and team performance was fully mediated by team communication quality. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

The effect of coworker knowledge sharing on performance and its boundary conditions: an interactional perspective.

PubMed

Kim, Seckyoung Loretta; Yun, Seokhwa

2015-03-01

Considering the importance of coworkers and knowledge sharing in current business environment, this study intends to advance understanding by investigating the effect of coworker knowledge sharing on focal employees' task performance. Furthermore, by taking an interactional perspective, this study examines the boundary conditions of coworker knowledge sharing on task performance. Data from 149 samples indicate that there is a positive relationship between coworker knowledge sharing and task performance, and this relationship is strengthened when general self-efficacy or abusive supervision is low rather than high. Our findings suggest that the recipients' characteristics and leaders' behaviors could be important contingent factors that limit the effect of coworker knowledge sharing on task performance. Implications for theory and practice are discussed. PsycINFO Database Record (c) 2015 APA, all rights reserved.

Family Life and Human Development: Sample Units, K-6. Revised.

ERIC Educational Resources Information Center

Prince George's County Public Schools, Upper Marlboro, MD.

Sample unit outlines, designed for kindergarten through grade six, define the content, activities, and assessment tasks appropriate to specific grade levels. The units have been extracted from the Board-approved curriculum, Health Education: The Curricular Approach to Optimal Health. The instructional guidelines for grade one are: describing a…

Quantitative analysis of defects in silicon: Silicon sheet growth development for the large area silicon sheet task of the low cost solar array project

NASA Technical Reports Server (NTRS)

Natesh, R.; Smith, J. M.; Qidwai, H. A.

1978-01-01

The various steps involved in the chemical polishing and etching of silicon samples are described and the data on twins, grain boundaries and dislocation pits from fifty-three (53) samples are discussed.

Learning the Language of Earth Science: Middle School Students' Explorations of Rocks and Minerals

ERIC Educational Resources Information Center

Reid-Griffin, Angelia

2016-01-01

The approaches and interpretations of a class of 6th graders and a class of 8th graders in a U.S. middle school asked to engage in tasks that involved using observations to describe and classify samples is the subject of this paper. Overall 8th graders were better able to perform the tasks, suggesting a developmental advantage aspect. However, the…

A Continuous False Belief Task Reveals Egocentric Biases in Children and Adolescents with Autism Spectrum Disorders

ERIC Educational Resources Information Center

Begeer, Sander; Bernstein, Daniel M.; van Wijhe, Jonas; Scheeren, Anke M.; Koot, Hans M.

2012-01-01

This study reports on a new false belief measure in a sample of 124 children and adolescents with or without high functioning autism (HFASD). In the classic paradigm, a participant predicts in which of two discrete locations a deceived protagonist will look for an object. In the current Sandbox task, the object is buried and reburied in a sandbox,…

CLUSTERS OF TASKS PERFORMED BY WASHINGTON STATE FARM OPERATORS ENGAGED IN SEVEN TYPES OF AGRICULTURAL PRODUCTION--GRAIN, DAIRY, FORESTRY, LIVESTOCK, POULTRY, HORTICULTURE, AND GENERAL FARMING. REPORT NO. 27.

ERIC Educational Resources Information Center

LONG, GILBERT A.

THE OBJECTIVE OF THIS STUDY WAS TO OBTAIN UP-TO-DATE FACTS ABOUT CLUSTERS OF TASKS PERFORMED BY WASHINGTON STATE FARM OPERATORS ENGAGED PRIMARILY IN PRODUCING GRAIN, LIVESTOCK, DAIRY COMMODITIES, POULTRY, FOREST PRODUCTS, HORTICULTURAL COMMODITIES, AND GENERAL FARMING COMMODITIES. FROM A RANDOM SAMPLE OF 267 FARMERS REPRESENTING THOSE CATEGORIES…

Effects of Stress on Judgment and Decision Making in Dynamic Tasks

DTIC Science & Technology

1991-06-01

their normal working conditions, (2) to ascertain whether the results from lens model theory and research in static tasks generalize to these...8217 normal work environment. A further generalization from lens model theory is that those precursors (secondary cues) that are more conceptual in...potential microburst cases. Although this sample of cases is admittedly smaller than desirable, many hours of technical work were required to remove

Alpha Control - A new Concept in SPM Control

NASA Astrophysics Data System (ADS)

Spizig, P.; Sanchen, D.; Volswinkler, G.; Ibach, W.; Koenen, J.

2006-03-01

Controlling modern Scanning Probe Microscopes demands highly sophisticated electronics. While flexibility and powerful computing power is of great importance in facilitating the variety of measurement modes, extremely low noise is also a necessity. Accordingly, modern SPM Controller designs are based on digital electronics to overcome the drawbacks of analog designs. While todays SPM controllers are based on DSPs or Microprocessors and often still incorporate analog parts, we are now introducing a completely new approach: Using a Field Programmable Gate Array (FPGA) to implement the digital control tasks allows unrivalled data processing speed by computing all tasks in parallel within a single chip. Time consuming task switching between data acquisition, digital filtering, scanning and the computing of feedback signals can be completely avoided. Together with a star topology to avoid any bus limitations in accessing the variety of ADCs and DACs, this design guarantees for the first time an entirely deterministic timing capability in the nanosecond regime for all tasks. This becomes especially useful for any external experiments which must be synchronized with the scan or for high speed scans that require not only closed loop control of the scanner, but also dynamic correction of the scan movement. Delicate samples additionally benefit from extremely high sample rates, allowing highly resolved signals and low noise levels.

Nonverbal imitation skills in children with specific language delay.

PubMed

Dohmen, Andrea; Chiat, Shula; Roy, Penny

2013-10-01

Research in children with language problems has focussed on verbal deficits, and we have less understanding of children's deficits with nonverbal sociocognitive skills which have been proposed to be important for language acquisition. This study was designed to investigate elicited nonverbal imitation in children with specific language delay (SLD). It is argued that difficulties in nonverbal imitation, which do not involve the processing of structural aspects of language, may be indicative of sociocognitive deficits. Participants were German-speaking typically developing children (n=60) and children with SLD (n=45) aged 2-3 ½ years. A novel battery of tasks measured their ability to imitate a range of nonverbal target acts that to a greater or lesser extent involve sociocognitive skills (body movements, instrumental acts on objects, pretend acts). Significant group differences were found for all body movement and pretend act tasks, but not for the instrumental act tasks. The poorer imitative performance of the SLD sample was not explained by motor or nonverbal cognitive skills. Thus, it appeared that the nature of the task affected children's imitation performance. It is argued that the ability to establish a sense of connectedness with the demonstrator was at the core of children's imitation difficulty in the SLD sample. Copyright © 2013 Elsevier Ltd. All rights reserved.

The Emergence of Symmetry in a Conditional Discrimination Task Using Different Responses as Propioceptive Samples in Pigeons

ERIC Educational Resources Information Center

Garcia, Andres; Benjumea, Santiago

2006-01-01

In Experiment 1, 10 pigeons were exposed to a successive symbolic matching-to-sample procedure in which the sample was generated by the pigeons' own behavior. Each trial began with both response keys illuminated white, one being the "correct" key and the other the "incorrect" key. The pigeons had no way of discriminating which key was correct and…

Using task performance to inform treatment planning for youth with ADHD: A systematic review.

PubMed

Molitor, Stephen J; Langberg, Joshua M

2017-12-01

The role that neuropsychological task performance plays in the assessment of Attention-Deficit/Hyperactivity Disorder (ADHD) is currently ambiguous, and findings are mixed regarding whether tasks have validity for diagnosing the disorder. Irrespective of their validity for diagnosing ADHD, neuropsychological tasks could provide valuable information to mental health professionals if they can inform recommendations for treatment targets and modalities. Therefore, this review sought to synthesize the available evidence related to the use of neuropsychological task performance as a tool for informing treatment planning for youth with ADHD. Reviewed studies focused on examinations of associations between task performance and academic, social, and health outcomes, as well as response to treatment. Twenty-five relevant studies using samples of youth diagnosed with ADHD in clinical, community, and school settings were identified. Review of the evidence suggests that task performance may be useful in identifying individuals with ADHD at risk for academic impairment. However, the evidence is less compelling for identifying youth at risk for impaired social functioning or poor health outcomes. The review also found that task performance is likely useful for predicting response to treatment with methylphenidate. Across studies, evidence indicated that interpreting task performance in an integrated manner, such as a factor score or mean score, was more consistently useful for predicting outcomes of interest than interpreting performance from a single task. Implications for the use of tasks in ADHD assessments are discussed, and future directions are outlined for further examining the clinical utility of task performance. Copyright © 2017 Elsevier Ltd. All rights reserved.

Automatic motor task selection via a bandit algorithm for a brain-controlled button

NASA Astrophysics Data System (ADS)

Fruitet, Joan; Carpentier, Alexandra; Munos, Rémi; Clerc, Maureen

2013-02-01

Objective. Brain-computer interfaces (BCIs) based on sensorimotor rhythms use a variety of motor tasks, such as imagining moving the right or left hand, the feet or the tongue. Finding the tasks that yield best performance, specifically to each user, is a time-consuming preliminary phase to a BCI experiment. This study presents a new adaptive procedure to automatically select (online) the most promising motor task for an asynchronous brain-controlled button. Approach. We develop for this purpose an adaptive algorithm UCB-classif based on the stochastic bandit theory and design an EEG experiment to test our method. We compare (offline) the adaptive algorithm to a naïve selection strategy which uses uniformly distributed samples from each task. We also run the adaptive algorithm online to fully validate the approach. Main results. By not wasting time on inefficient tasks, and focusing on the most promising ones, this algorithm results in a faster task selection and a more efficient use of the BCI training session. More precisely, the offline analysis reveals that the use of this algorithm can reduce the time needed to select the most appropriate task by almost half without loss in precision, or alternatively, allow us to investigate twice the number of tasks within a similar time span. Online tests confirm that the method leads to an optimal task selection. Significance. This study is the first one to optimize the task selection phase by an adaptive procedure. By increasing the number of tasks that can be tested in a given time span, the proposed method could contribute to reducing ‘BCI illiteracy’.

False belief understanding and "cool" inhibitory control in 3-and 4-years-old Italian children.

PubMed

Bellagamba, Francesca; Addessi, Elsa; Focaroli, Valentina; Pecora, Giulia; Maggiorelli, Valentina; Pace, Beatrice; Paglieri, Fabio

2015-01-01

During preschool years, major developments occur in both executive function and theory of mind (ToM), and several studies have demonstrated a correlation between these processes. Research on the development of inhibitory control (IC) has distinguished between more cognitive, "cool" aspects of self-control, measured by conflict tasks, that require inhibiting an habitual response to generate an arbitrary one, and "hot," affective aspects, such as affective decision making, measured by delay tasks, that require inhibition of a prepotent response. The aim of this study was to investigate the relations between 3- and 4-year-olds' performance on a task measuring false belief understanding, the most widely used index of ToM in preschoolers, and three tasks measuring cognitive versus affective aspects of IC. To this end, we tested 101 Italian preschool children in four tasks: (a) the Unexpected Content False Belief task, (b) the Conflict task (a simplified version of the Day-Night Stroop task), (c) the Delay task, and (d) the Delay Choice task. Children's receptive vocabulary was assessed by the Peabody Picture Vocabulary test. Children's performance in the False Belief task was significantly related only to performance in the Conflict task, controlling for vocabulary and age. Importantly, children's performance in the Conflict task did not significantly correlate with their performance in the Delay task or in the Delay Choice task, suggesting that these tasks measure different components of IC. The dissociation between the Conflict and the Delay tasks may indicate that monitoring and regulating a cool process (as flexible categorization) may involve different abilities than monitoring and regulating a hot process (not touching an available and highly attractive stimulus or choosing between a smaller immediate option and a larger delayed one). Moreover, our findings support the view that "cool" aspects of IC and ToM are interrelated, extending to an Italian sample of children previous findings on an association between self-control and ToM.

False belief understanding and “cool” inhibitory control in 3-and 4-years-old Italian children

PubMed Central

Bellagamba, Francesca; Addessi, Elsa; Focaroli, Valentina; Pecora, Giulia; Maggiorelli, Valentina; Pace, Beatrice; Paglieri, Fabio

2015-01-01

During preschool years, major developments occur in both executive function and theory of mind (ToM), and several studies have demonstrated a correlation between these processes. Research on the development of inhibitory control (IC) has distinguished between more cognitive, “cool” aspects of self-control, measured by conflict tasks, that require inhibiting an habitual response to generate an arbitrary one, and “hot,” affective aspects, such as affective decision making, measured by delay tasks, that require inhibition of a prepotent response. The aim of this study was to investigate the relations between 3- and 4-year-olds’ performance on a task measuring false belief understanding, the most widely used index of ToM in preschoolers, and three tasks measuring cognitive versus affective aspects of IC. To this end, we tested 101 Italian preschool children in four tasks: (a) the Unexpected Content False Belief task, (b) the Conflict task (a simplified version of the Day–Night Stroop task), (c) the Delay task, and (d) the Delay Choice task. Children’s receptive vocabulary was assessed by the Peabody Picture Vocabulary test. Children’s performance in the False Belief task was significantly related only to performance in the Conflict task, controlling for vocabulary and age. Importantly, children’s performance in the Conflict task did not significantly correlate with their performance in the Delay task or in the Delay Choice task, suggesting that these tasks measure different components of IC. The dissociation between the Conflict and the Delay tasks may indicate that monitoring and regulating a cool process (as flexible categorization) may involve different abilities than monitoring and regulating a hot process (not touching an available and highly attractive stimulus or choosing between a smaller immediate option and a larger delayed one). Moreover, our findings support the view that “cool” aspects of IC and ToM are interrelated, extending to an Italian sample of children previous findings on an association between self-control and ToM. PMID:26175700

Frontal brain activation in young children during picture book reading with their mothers

PubMed Central

Ohgi, Shohei; Loo, Kek Khee; Mizuike, Chihiro

2010-01-01

Aim This study was to measure changes in frontal brain activation in young children during picture book reading with their mothers. Methods The cross-sectional sample consisted of 15 young Japanese children (8 girls and 7 boys, mean age 23.1±3.4). Two experimental tasks were presented as follows: Task 1 (picture book reading with their mothers); Task 2 (viewing of book-on-video). Duration of task stimulus was 180 sec and the 60 sec interval was filled. Brain activation was measured using an optical topography system. Results Significant increases in oxy-Hb were observed in both right and left frontal areas in response to Task 1 compared to Task 2. There were significant correlations between child’s brain activity and mothers’ and children’s verbal – nonverbal behaviors. Conclusion There was greater frontal lobe activation in children when they were engaged in a picture book reading task with their mothers, as opposed to passive viewing of a videotape in which the story was read to them. Social and verbal engagement of the mother in reading picture books with her young child may mediate frontal brain activity in the child. PMID:19849672

Assessing Measurement Invariance for Spanish Sentence Repetition and Morphology Elicitation Tasks.

PubMed

Kapantzoglou, Maria; Thompson, Marilyn S; Gray, Shelley; Restrepo, M Adelaida

2016-04-01

The purpose of this study was to evaluate evidence supporting the construct validity of two grammatical tasks (sentence repetition, morphology elicitation) included in the Spanish Screener for Language Impairment in Children (Restrepo, Gorin, & Gray, 2013). We evaluated if the tasks measured the targeted grammatical skills in the same way across predominantly Spanish-speaking children with typical language development and those with primary language impairment. A multiple-group, confirmatory factor analytic approach was applied to examine factorial invariance in a sample of 307 predominantly Spanish-speaking children (177 with typical language development; 130 with primary language impairment). The 2 newly developed grammatical tasks were modeled as measures in a unidimensional confirmatory factor analytic model along with 3 well-established grammatical measures from the Clinical Evaluation of Language Fundamentals-Fourth Edition, Spanish (Wiig, Semel, & Secord, 2006). Results suggest that both new tasks measured the construct of grammatical skills for both language-ability groups in an equivalent manner. There was no evidence of bias related to children's language status for the Spanish Screener for Language Impairment in Children Sentence Repetition or Morphology Elicitation tasks. Results provide support for the validity of the new tasks as measures of grammatical skills.

Impaired preparatory re-mapping of stimulus-response associations and rule-implementation in schizophrenic patients--the role for differences in early processing.

PubMed

Finke, Mareike; Barceló, Francisco; Garolera, Maite; Cortiñas, Miriam; Garrido, Gemma; Pajares, Marta; Escera, Carles

2011-07-01

An accurate representation of task-set information is needed for successful goal directed behavior. Recent studies point to disturbances in the early processing stages as plausible causes for task-switching deficits in schizophrenia. A task-cueing protocol was administered to a group of schizophrenic patients and compared with a sample of age-matched healthy controls. Patients responded slower and less accurate compared with controls in all conditions. The concurrent recording of event-related brain potentials to contextual cues and target events revealed abnormalities in the early processing of both cue-locked and target-locked N1 potentials. Abnormally enhanced target-locked P2 amplitudes were observed in schizophrenic patients for task-switch trials only, suggesting disrupted stimulus evaluation and memory retrieval processes. The endogenous P3 potentials discriminated between task conditions but without further differences between groups. These results suggest that the observed impairments in task-switching behavior were not specifically related to anticipatory set-shifting, but derived from a deficit in the implementation of task-set representations at target onset in the presence of irrelevant and conflicting information. Copyright © 2011 Elsevier B.V. All rights reserved.

Thematic Matching as Remedial Teaching for Symbolic Matching for Individuals with Autism Spectrum Disorder

PubMed Central

Lionello-DeNolf, Karen M.; Farber, Rachel; Jones, B. Max; Dube, William V.

2014-01-01

Matching-to-sample (MTS) is often used to teach symbolic relationships between spoken or printed words and their referents to children with intellectual and developmental disabilities. However, many children have difficulty learning symbolic matching, even though they may demonstrate generalized identity matching. The current study investigated whether training on symbolic MTS tasks in which the stimuli are physically dissimilar but members of familiar categories (i.e., thematic matching) can remediate an individual’s difficulty learning symbolic MTS tasks involving non-representative stimuli. Three adolescent males diagnosed with autism spectrum disorder were first trained on symbolic MTS tasks with unfamiliar, non-representative form stimuli. Thematic matching was introduced after the participants failed to learn 0, 2 or 4 symbolic MTS tasks and before additional symbolic MTS tasks were introduced. After exposure to thematic matching, accuracy on symbolic MTS tasks with novel stimuli increased to above chance for all participants. For two participants, high accuracy (> 90%) was achieved on a majority of these sessions. Thus, thematic matching may be an effective intervention for students with limited verbal repertoires and who have difficulty learning symbolic MTS tasks. Possible explanations for the facilitative effect of thematic matching are considered and warrant further investigation. PMID:24634695

Cognitive processes in children's reading and attention: the role of working memory, divided attention, and response inhibition.

PubMed

Savage, Robert; Cornish, Kim; Manly, Tom; Hollis, Chris

2006-08-01

Children experiencing attention difficulties have documented cognitive deficits in working memory (WM), response inhibition and dual tasks. Recent evidence suggests however that these same cognitive processes are also closely associated with reading acquisition. This paper therefore explores whether these variables predicted attention difficulties or reading among 123 children with and without significant attention problems sampled from the school population. Children were screened using current WM and attention task measures. Three factors explained variance in WM and attention tasks. Response inhibition tasks loaded mainly with central executive measures, but a dual processing task loaded with the visual-spatial WM measures. Phonological loop measures loaded independently of attention measures. After controls for age, IQ and attention-group membership, phonological loop and 'central processing' measures both predicted reading ability. A 'visual memory/dual-task' factor predicted attention group membership after controls for age, IQ and reading ability. Results thus suggest that some of the processes previously assumed to be predictive of attention problems may reflect processes involved in reading acquisition. Visual memory and dual-task functioning are, however, purer indices of cognitive difficulty in children experiencing attention problems.

Examining methodological variation in response inhibition: The effects of outcome measures and task characteristics on age-related differences.

PubMed

Klenberg, Liisa; Närhi, Vesa; Korkman, Marit; Hokkanen, Laura

2015-01-01

This study addressed methodological issues common to developmental studies on response inhibition. Age-related differences were investigated using two Stroop-like tasks with different levels of complexity and comparing different outcome measures in a sample of 340 children and adolescents aged 7-15 years. First, speed and accuracy of task performance were examined; the results showing that improvement in speed continued until age 13 in both the basic naming task and the two inhibition tasks. Improvement in accuracy was less consistent and continued until age 9 or 13 years. Second, two different algorithms were employed to control for the effects of basic processes in inhibition tasks. The difference algorithm indicated age-related differences similar to those for speed. The ratio algorithm, however, suggested earlier deceleration of development of response inhibition at 9 or 11 years of age. Factors related to the cognitive requirements and presented stimuli also had an effect on the results. The present findings shed light on the inconsistencies in the developmental studies of response inhibition and demonstrated that the selection of outcome measures and task characteristics are critical because they affect the way development is depicted.

Training attentional control in older adults

PubMed Central

MacKay-Brandt, Anna

2013-01-01

Recent research has demonstrated benefits for older adults from training attentional control using a variable priority strategy, but the construct validity of the training task and the degree to which benefits of training transfer to other contexts are unclear. The goal of this study was to characterize baseline performance on the training task in a sample of 105 healthy older adults and to test for transfer of training in a subset (n = 21). Training gains after 5 days and extent of transfer was compared to another subset (n = 20) that served as a control group. Baseline performance on the training task was characterized by a two-factor model of working memory and processing speed. Processing speed correlated with the training task. Training gains in speed and accuracy were reliable and robust (ps <.001, η2 = .57 to .90). Transfer to an analogous task was observed (ps <.05, η2 = .10 to .17). The beneficial effect of training did not translate to improved performance on related measures of processing speed. This study highlights the robust effect of training and transfer to a similar context using a variable priority training task. Although processing speed is an important aspect of the training task, training benefit is either related to an untested aspect of the training task or transfer of training is limited to the training context. PMID:21728889

Toward a human-centered hyperlipidemia management system: the interaction between internal and external information on relational data search.

PubMed

Gong, Yang; Zhang, Jiajie

2011-04-01

In a distributed information search task, data representation and cognitive distribution jointly affect user search performance in terms of response time and accuracy. Guided by UFuRT (User, Function, Representation, Task), a human-centered framework, we proposed a search model and task taxonomy. The model defines its application in the context of healthcare setting. The taxonomy clarifies the legitimate operations for each type of search task of relational data. We then developed experimental prototypes of hyperlipidemia data displays. Based on the displays, we tested the search tasks performance through two experiments. The experiments are of a within-subject design with a random sample of 24 participants. The results support our hypotheses and validate the prediction of the model and task taxonomy. In this study, representation dimensions, data scales, and search task types are the main factors in determining search efficiency and effectiveness. Specifically, the more external representations provided on the interface the better search task performance of users. The results also suggest the ideal search performance occurs when the question type and its corresponding data scale representation match. The implications of the study lie in contributing to the effective design of search interface for relational data, especially laboratory results, which could be more effectively designed in electronic medical records.

Real-Time Non-Intrusive Assessment of Viewing Distance during Computer Use.

PubMed

Argilés, Marc; Cardona, Genís; Pérez-Cabré, Elisabet; Pérez-Magrané, Ramon; Morcego, Bernardo; Gispets, Joan

2016-12-01

To develop and test the sensitivity of an ultrasound-based sensor to assess the viewing distance of visual display terminals operators in real-time conditions. A modified ultrasound sensor was attached to a computer display to assess viewing distance in real time. Sensor functionality was tested on a sample of 20 healthy participants while they conducted four 10-minute randomly presented typical computer tasks (a match-three puzzle game, a video documentary, a task requiring participants to complete a series of sentences, and a predefined internet search). The ultrasound sensor offered good measurement repeatability. Game, text completion, and web search tasks were conducted at shorter viewing distances (54.4 cm [95% CI 51.3-57.5 cm], 54.5 cm [95% CI 51.1-58.0 cm], and 54.5 cm [95% CI 51.4-57.7 cm], respectively) than the video task (62.3 cm [95% CI 58.9-65.7 cm]). Statistically significant differences were found between the video task and the other three tasks (all p < 0.05). Range of viewing distances (from 22 to 27 cm) was similar for all tasks (F = 0.996; p = 0.413). Real-time assessment of the viewing distance of computer users with a non-intrusive ultrasonic device disclosed a task-dependent pattern.

Unimodal and crossmodal working memory representations of visual and kinesthetic movement trajectories.

PubMed

Seemüller, Anna; Fiehler, Katja; Rösler, Frank

2011-01-01

The present study investigated whether visual and kinesthetic stimuli are stored as multisensory or modality-specific representations in unimodal and crossmodal working memory tasks. To this end, angle-shaped movement trajectories were presented to 16 subjects in delayed matching-to-sample tasks either visually or kinesthetically during encoding and recognition. During the retention interval, a secondary visual or kinesthetic interference task was inserted either immediately or with a delay after encoding. The modality of the interference task interacted significantly with the encoding modality. After visual encoding, memory was more impaired by a visual than by a kinesthetic secondary task, while after kinesthetic encoding the pattern was reversed. The time when the secondary task had to be performed interacted with the encoding modality as well. For visual encoding, memory was more impaired, when the secondary task had to be performed at the beginning of the retention interval. In contrast, memory after kinesthetic encoding was more affected, when the secondary task was introduced later in the retention interval. The findings suggest that working memory traces are maintained in a modality-specific format characterized by distinct consolidation processes that take longer after kinesthetic than after visual encoding. Copyright © 2010 Elsevier B.V. All rights reserved.

Strategy generalization across orientation tasks: testing a computational cognitive model.

PubMed

Gunzelmann, Glenn

2008-07-08

Humans use their spatial information processing abilities flexibly to facilitate problem solving and decision making in a variety of tasks. This article explores the question of whether a general strategy can be adapted for performing two different spatial orientation tasks by testing the predictions of a computational cognitive model. Human performance was measured on an orientation task requiring participants to identify the location of a target either on a map (find-on-map) or within an egocentric view of a space (find-in-scene). A general strategy instantiated in a computational cognitive model of the find-on-map task, based on the results from Gunzelmann and Anderson (2006), was adapted to perform both tasks and used to generate performance predictions for a new study. The qualitative fit of the model to the human data supports the view that participants were able to tailor a general strategy to the requirements of particular spatial tasks. The quantitative differences between the predictions of the model and the performance of human participants in the new experiment expose individual differences in sample populations. The model provides a means of accounting for those differences and a framework for understanding how human spatial abilities are applied to naturalistic spatial tasks that involve reasoning with maps. 2008 Cognitive Science Society, Inc.

Fast and Accurate Learning When Making Discrete Numerical Estimates.

PubMed

Sanborn, Adam N; Beierholm, Ulrik R

2016-04-01

Many everyday estimation tasks have an inherently discrete nature, whether the task is counting objects (e.g., a number of paint buckets) or estimating discretized continuous variables (e.g., the number of paint buckets needed to paint a room). While Bayesian inference is often used for modeling estimates made along continuous scales, discrete numerical estimates have not received as much attention, despite their common everyday occurrence. Using two tasks, a numerosity task and an area estimation task, we invoke Bayesian decision theory to characterize how people learn discrete numerical distributions and make numerical estimates. Across three experiments with novel stimulus distributions we found that participants fell between two common decision functions for converting their uncertain representation into a response: drawing a sample from their posterior distribution and taking the maximum of their posterior distribution. While this was consistent with the decision function found in previous work using continuous estimation tasks, surprisingly the prior distributions learned by participants in our experiments were much more adaptive: When making continuous estimates, participants have required thousands of trials to learn bimodal priors, but in our tasks participants learned discrete bimodal and even discrete quadrimodal priors within a few hundred trials. This makes discrete numerical estimation tasks good testbeds for investigating how people learn and make estimates.

Fast and Accurate Learning When Making Discrete Numerical Estimates

PubMed Central

Sanborn, Adam N.; Beierholm, Ulrik R.

2016-01-01

Many everyday estimation tasks have an inherently discrete nature, whether the task is counting objects (e.g., a number of paint buckets) or estimating discretized continuous variables (e.g., the number of paint buckets needed to paint a room). While Bayesian inference is often used for modeling estimates made along continuous scales, discrete numerical estimates have not received as much attention, despite their common everyday occurrence. Using two tasks, a numerosity task and an area estimation task, we invoke Bayesian decision theory to characterize how people learn discrete numerical distributions and make numerical estimates. Across three experiments with novel stimulus distributions we found that participants fell between two common decision functions for converting their uncertain representation into a response: drawing a sample from their posterior distribution and taking the maximum of their posterior distribution. While this was consistent with the decision function found in previous work using continuous estimation tasks, surprisingly the prior distributions learned by participants in our experiments were much more adaptive: When making continuous estimates, participants have required thousands of trials to learn bimodal priors, but in our tasks participants learned discrete bimodal and even discrete quadrimodal priors within a few hundred trials. This makes discrete numerical estimation tasks good testbeds for investigating how people learn and make estimates. PMID:27070155

EEG Frequency Changes Prior to Making Errors in an Easy Stroop Task

PubMed Central

Atchley, Rachel; Klee, Daniel; Oken, Barry

2017-01-01

Background: Mind-wandering is a form of off-task attention that has been associated with negative affect and rumination. The goal of this study was to assess potential electroencephalographic markers of task-unrelated thought, or mind-wandering state, as related to error rates during a specialized cognitive task. We used EEG to record frontal frequency band activity while participants completed a Stroop task that was modified to induce boredom, task-unrelated thought, and therefore mind-wandering. Methods: A convenience sample of 27 older adults (50–80 years) completed a computerized Stroop matching task. Half of the Stroop trials were congruent (word/color match), and the other half were incongruent (mismatched). Behavioral data and EEG recordings were assessed. EEG analysis focused on the 1-s epochs prior to stimulus presentation in order to compare trials followed by correct versus incorrect responses. Results: Participants made errors on 9% of incongruent trials. There were no errors on congruent trials. There was a decrease in alpha and theta band activity during the epochs followed by error responses. Conclusion: Although replication of these results is necessary, these findings suggest that potential mind-wandering, as evidenced by errors, can be characterized by a decrease in alpha and theta activity compared to on-task, accurate performance periods. PMID:29163101

Manual asymmetry in older adults on a complex coincidence-anticipation task.

PubMed

Rodrigues, Paula Cristina Dos Santos; Silva, João Miguel Carvalho da; Barreiros, João Manuel Pardal; Vasconcelos, Maria Olga Fernandes

2018-04-20

Age-related asymmetrical functional decline was tested in a sample of 57 right-handed volunteers between 65 and 85 years of age. Participants performed a complex coincidence-anticipation (CA) task with both preferred and non-preferred hands. Results demonstrated that the proficiency of a complex CA task was similar for the 2 age groups, but different for the 2 hands. The non-preferred hand was more proficient for temporal accuracy but not for response timing, which was similar for both hands. Moreover, the lack of interaction between age and hand both in response timing and response accuracy reveal symmetric performance across ages.

Executive and Reward-Related Function in Pediatric Obesity: A Meta-Analysis.

PubMed

Pearce, Alaina L; Leonhardt, Christine A; Vaidya, Chandan J

2018-06-06

This study examined the effect of pediatric obesity on executive function and reward-related decision-making, cognitive processes that are relevant to obesogenic behaviors, and evaluated their association with sample (e.g., age, gender, intelligence, and socioeconomic status, SES) and study/task (e.g., categorical/continuous variable, food stimuli) characteristics. A random-effects meta-analysis was conducted using Hedge's g effect sizes of published studies from 1960 to 2016, limited to children younger than the age of 21 years without medical comorbidities. Analysis included estimation of heterogeneity (τ 2 ), publication bias (funnel-plot symmetry and fail-safe N), and sensitivity analyses for sample and study/task characteristics. Across 68 studies with 70 samples, obesity was associated with worse functioning overall (-0.24; 95CI: -0.30 to -0.19; p < 0.001) and for each component process (attention, switching, inhibition, interference, working memory, reward, delay of gratification: -0.19 to -0.38; p's < 0.017), except trait impulsivity (-0.06; 95CI: -0.18 to 0.07). Deficits increased with age and female composition of the sample for inhibition (p = 0.002). No other characteristics moderated effect of obesity. Small-to-moderate negative associations with obesity were observed for executive and reward-related performance, but not on reported impulsivity in studies with children younger than the age of 21 years. These results were not moderated by IQ, SES, and study/task characteristics. Age and gender moderated association with inhibition, with a larger obesity-related deficit in older and predominantly female samples. These results suggest cognitive and demographic intervention targets for prevention and mitigation of obesogenic behavior.

At the dawn of delegation? Experiences and attitudes of general practitioners in Germany - a questionnaire survey.

PubMed

Goetz, Katja; Kornitzky, Anna; Mahnkopf, Janis; Steinhäuser, Jost

2017-12-19

In the future, 'delegation' as task shifting from general practitioners (GPs) to non-physicians will be important in primary care. Therefore, the aim of this study was to evaluate the attitudes towards the concept of task shifting and to identify predictors of a positive attitude towards task shifting from the perspective of GPs. This cross-sectional questionnaire study analysed attitudes towards the concept of task shifting and delegated tasks from the perspective of GPs who were recruited in the German federal state of Schleswig-Holstein. Descriptive statistics and binary regression analyses were computed to identify potential predictors of a positive attitude towards task shifting. Out of 1538 questionnaires distributed, 577 GP questionnaires were returned (response rate: 37.5%). A total of 53.2% of the respondents were male, and 37.3% were female. A positive attitude regarding task shifting was shown by 49% of the participating GPs. The highest level of agreement (95.2%) was found for time savings with task shifting, and a lower agreement (39%) was found regarding the lack of clarity concerning the responsibilities and legal aspects with regards to task shifting. The most frequently delegated tasks were recording electrocardiograms and measuring blood glucose levels. A positive attitude towards task shifting was positively associated with higher job satisfaction and a need for qualified staff. Our sample of GPs for this study was very open-minded towards the concept of task shifting. Germany is just beginning this delegation, but the implementation of task shifting depends on different aspects, such as legal requirements, adequate payment and qualified staff. Finally, there is a need for continuing professional development in primary care teams, especially for non-clinical practice staff.

Task-Rest Modulation of Basal Ganglia Connectivity in Mild to Moderate Parkinson’s Disease

PubMed Central

Müller-Oehring, Eva M.; Sullivan, Edith V.; Pfefferbaum, Adolf; Huang, Neng C.; Poston, Kathleen L.; Bronte-Stewart, Helen M.; Schulte, Tilman

2014-01-01

Parkinson’s disease (PD) is associated with abnormal synchronization in basal ganglia-thalamo-cortical loops. We tested whether early PD patients without demonstrable cognitive impairment exhibit abnormal modulation of functional connectivity at rest, while engaged in a task, or both. PD and healthy controls underwent two functional MRI scans: a resting-state scan and a Stroop Match-to-Sample task scan. Rest-task modulation of basal ganglia (BG) connectivity was tested using seed-to-voxel connectivity analysis with task and rest time series as conditions. Despite substantial overlap of BG–cortical connectivity patterns in both groups, connectivity differences between groups had clinical and behavioral correlates. During rest, stronger putamen–medial parietal and pallidum–occipital connectivity in PD than controls was associated with worse task performance and more severe PD symptoms suggesting that abnormalities in resting-state connectivity denote neural network dedifferentiation. During the executive task, PD patients showed weaker BG-cortical connectivity than controls, i.e., between caudate–supramarginal gyrus and pallidum–inferior prefrontal regions, that was related to more severe PD symptoms and worse task performance. Yet, task processing also evoked stronger striatal–cortical connectivity, specifically between caudate–prefrontal, caudate–precuneus, and putamen–motor/premotor regions in PD relative to controls, which was related to less severe PD symptoms and better performance on the Stroop task. Thus, stronger task-evoked striatal connectivity in PD demonstrated compensatory neural network enhancement to meet task demands and improve performance levels. fMRI-based network analysis revealed that despite resting-state BG network compromise in PD, BG connectivity to prefrontal, premotor, and precuneus regions can be adequately invoked during executive control demands enabling near normal task performance. PMID:25280970

Initiating an ergonomic analysis. A process for jobs with highly variable tasks.

PubMed

Conrad, K M; Lavender, S A; Reichelt, P A; Meyer, F T

2000-09-01

Occupational health nurses play a vital role in addressing ergonomic problems in the workplace. Describing and documenting exposure to ergonomic risk factors is a relatively straightforward process in jobs in which the work is repetitive. In other types of work, the analysis becomes much more challenging because tasks may be repeated infrequently, or at irregular time intervals, or under different environmental and temporal conditions, thereby making it difficult to observe a "representative" sample of the work performed. This article describes a process used to identify highly variable job tasks for ergonomic analyses. The identification of tasks for ergonomic analysis was a two step process involving interviews and a survey of firefighters and paramedics from a consortium of 14 suburban fire departments. The interviews were used to generate a list of frequently performed, physically strenuous job tasks and to capture clear descriptions of those tasks and associated roles. The goals of the survey were to confirm the interview findings across the entire target population and to quantify the frequency and degree of strenuousness of each task. In turn, the quantitative results from the survey were used to prioritize job tasks for simulation. Although this process was used to study firefighters and paramedics, the approach is likely to be suitable for many other types of occupations in which the tasks are highly variable in content and irregular in frequency.

Developing a unified list of physicians' reasoning tasks during clinical encounters.

PubMed

Goldszmidt, Mark; Minda, John Paul; Bordage, Georges

2013-03-01

The clinical reasoning literature focuses on how physicians reason while making decisions, rather than on what they reason about while performing their clinical tasks. In an attempt to provide a common language for discussing, teaching, and researching clinical reasoning, the authors undertook the task of developing a unified list of physicians' reasoning tasks, or what they reason about, during clinical encounters. The authors compiled an initial list of 20 reasoning tasks based on the literature from four content areas--clinical reasoning, communications, medical errors, and clinical guidelines. In the summer and fall of 2010, they surveyed a purposive sample of 46 international experts in clinical reasoning and communications. From the results of the first survey, the authors refined their list of reasoning tasks, then resurveyed 22 of the original participants. From the results of the second survey, they further refined their list and validated the inclusion of the reasoning tasks. Twenty-four of 46 (52%) and 15 of 22 (65%) participants completed the first- and second-round surveys, respectively. Following the second-round survey, the authors' list included 24 reasoning tasks, and a clinical example corresponding to each, that fell into four broad categories: framing the encounter (3), diagnosis (8), management (11), and self-reflection (2). The development of this unified list represents a first step in offering a vocabulary for discussing, reflecting on, teaching, and studying physicians' reasoning tasks during clinical encounters.

An exploratory study of long-haul truck drivers' secondary tasks and reasons for performing them.

PubMed

Iseland, Tobias; Johansson, Emma; Skoog, Siri; Dåderman, Anna M

2018-08-01

Research on drivers has shown how certain visual-manual secondary tasks, unrelated to driving, increase the risk of being involved in crashes. The purpose of the study was to investigate (1) if long-haul truck drivers in Sweden engage in secondary tasks while driving, what tasks are performed and how frequently, (2) the drivers' self-perceived reason/s for performing them, and (3) if psychological factors might reveal reasons for their engaging in secondary tasks. The study comprised 13 long-haul truck drivers and was conducted through observations, interviews, and questionnaires. The drivers performed secondary tasks, such as work environment related "necessities" (e.g., getting food and/or beverages from the refrigerator/bag, eating, drinking, removing a jacket, face rubbing, and adjusting the seat), interacting with a mobile phone/in-truck technology, and doing administrative tasks. The long-haul truck drivers feel bored and use secondary tasks as a coping strategy to alleviate boredom/drowsiness, and for social interaction. The higher number of performed secondary tasks could be explained by lower age, shorter driver experience, less openness to experience, lower honesty-humility, lower perceived stress, lower workload, and by higher health-related quality of life. These explanatory results may serve as a starting point for further studies on large samples to develop a safer and healthier environment for long-haul truck drivers. Copyright © 2018. Published by Elsevier Ltd.

Effect of Tai Chi Training on Dual-Tasking Performance That Involves Stepping Down among Stroke Survivors: A Pilot Study.

PubMed

Chan, Wing-Nga; Tsang, William Wai-Nam

2017-01-01

Descending stairs demands attention and neuromuscular control, especially with dual-tasking. Studies have demonstrated that stroke often degrades a survivor's ability to descend stairs. Tai Chi has been shown to improve dual-tasking performance of healthy older adults, but no such study has been conducted in stroke survivors. This study investigated the effect of Tai Chi training on dual-tasking performance that involved stepping down and compared it with that of conventional exercise among stroke survivors. Subjects were randomized into Tai Chi ( n = 9), conventional exercise ( n = 8), and control ( n = 9) groups. Those in the former two groups received 12-week training. Assessments included auditory Stroop test, stepping down test, and dual-tasking test involving both simultaneously. They were evaluated before training (time-1), after training (time-2), and one month after training (time-3). Tai Chi group showed significant improvement in the auditory Stroop test from time-1 to time-3 and the performance was significantly better than that of the conventional exercise group in time-3. No significant effect was found in the stepping down task or dual-tasking in the control group. These results suggest a beneficial effect of Tai Chi training on cognition among stroke survivors without compromising physical task performance in dual-tasking. The effect was better than the conventional exercise group. Nevertheless, further research with a larger sample is warranted.

The Importance of Team Sex Composition in Team-Training Research Employing Complex Psychomotor Tasks.

PubMed

Jarrett, Steven M; Glaze, Ryan M; Schurig, Ira; Arthur, Winfred

2017-08-01

The relationship between team sex composition and team performance on a complex psychomotor task was examined because these types of tasks are commonly used in the lab-based teams literature. Despite well-documented sex-based differences on complex psychomotor tasks, the preponderance of studies-mainly lab based-that use these tasks makes no mention of the sex composition of teams across or within experimental conditions. A sample of 123 four-person teams with varying team sex composition learned and performed a complex psychomotor task, Steal Beasts Pro PE. Each team completed a 5-hr protocol whereby they conducted several performance missions. The results indicated significant large mean differences such that teams with larger proportions of males had higher performance scores. These findings demonstrate the potential effect of team sex composition on the validity of studies that use complex psychomotor tasks to explore and investigate team performance-related phenomena when (a) team sex composition is not a focal variable of interest and (b) it is not accounted for or controlled. Given the proclivity of complex psychomotor action-based tasks used in lab-based team studies, it is important to understand and control for the impact of team sex composition on team performance. When team sex composition is not controlled for, either methodologically or statistically, it may affect the validity of the results in teams studies using these types of tasks.

Quantifying the Physiological Stress Response to Simulated Maritime Pilotage Tasks: The Influence of Task Complexity and Pilot Experience.

PubMed

Main, Luana C; Wolkow, Alexander; Chambers, Timothy P

2017-11-01

The aim of this study was to quantify the stress associated with performing maritime pilotage tasks in a high-fidelity simulator. Eight trainee and 13 maritime pilots completed two simulated pilotage tasks of varying complexity. Salivary cortisol samples were collected pre- and post-simulation for both trials. Heart rate was measured continuously throughout the study. Significant changes in salivary cortisol (P = 0.000, η = 0.139), average (P = 0.006, η = 0.087), and peak heart rate (P = 0.013, η = 0.077) from pre- to postsimulation were found. Varying task complexity did partially influence stress response; average (P = 0.016, η = 0.026) and peak heart rate (P = 0.034, η = 0.020) were higher in the experimental condition. Trainees also recorded higher average (P = 0.000, η = 0.054) and peak heart rates (P = 0.027, η = 0.022). Performing simulated pilotage tasks evoked a measurable stress response in both trainee and expert maritime pilots.